/usr/src/gnu/usr.bin/clang/libclangSerialization/../../../llvm/clang/lib/Serialization/ASTReader.cpp

Bug Summary

File:	src/gnu/usr.bin/clang/libclangSerialization/../../../llvm/clang/lib/Serialization/ASTReader.cpp
Warning:	line 4952, column 37 Called C++ object pointer is null
Annotated Source Code

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clang -cc1 -cc1 -triple amd64-unknown-openbsd7.0 -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name ASTReader.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -mrelocation-model static -mframe-pointer=all -relaxed-aliasing -fno-rounding-math -mconstructor-aliases -munwind-tables -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -fcoverage-compilation-dir=/usr/src/gnu/usr.bin/clang/libclangSerialization/obj -resource-dir /usr/local/lib/clang/13.0.0 -I /usr/src/gnu/usr.bin/clang/libclangSerialization/../../../llvm/clang/include -I /usr/src/gnu/usr.bin/clang/libclangSerialization/../../../llvm/llvm/include -I /usr/src/gnu/usr.bin/clang/libclangSerialization/../include -I /usr/src/gnu/usr.bin/clang/libclangSerialization/obj -I /usr/src/gnu/usr.bin/clang/libclangSerialization/obj/../include -D NDEBUG -D __STDC_LIMIT_MACROS -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D LLVM_PREFIX="/usr" -internal-isystem /usr/include/c++/v1 -internal-isystem /usr/local/lib/clang/13.0.0/include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-comment -std=c++14 -fdeprecated-macro -fdebug-compilation-dir=/usr/src/gnu/usr.bin/clang/libclangSerialization/obj -ferror-limit 19 -fvisibility-inlines-hidden -fwrapv -stack-protector 2 -fno-rtti -fgnuc-version=4.2.1 -vectorize-loops -vectorize-slp -fno-builtin-malloc -fno-builtin-calloc -fno-builtin-realloc -fno-builtin-valloc -fno-builtin-free -fno-builtin-strdup -fno-builtin-strndup -analyzer-output=html -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /home/ben/Projects/vmm/scan-build/2022-01-12-194120-40624-1 -x c++ /usr/src/gnu/usr.bin/clang/libclangSerialization/../../../llvm/clang/lib/Serialization/ASTReader.cpp
/usr/src/gnu/usr.bin/clang/libclangSerialization/../../../llvm/clang/lib/Serialization/ASTReader.cpp

→
1//===- ASTReader.cpp - AST File Reader ------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9//  This file defines the ASTReader class, which reads AST files.
10//
11//===----------------------------------------------------------------------===//

13#include "clang/Basic/OpenMPKinds.h"
14#include "clang/Serialization/ASTRecordReader.h"
15#include "ASTCommon.h"
16#include "ASTReaderInternals.h"
17#include "clang/AST/AbstractTypeReader.h"
18#include "clang/AST/ASTConsumer.h"
19#include "clang/AST/ASTContext.h"
20#include "clang/AST/ASTMutationListener.h"
21#include "clang/AST/ASTUnresolvedSet.h"
22#include "clang/AST/Decl.h"
23#include "clang/AST/DeclBase.h"
24#include "clang/AST/DeclCXX.h"
25#include "clang/AST/DeclFriend.h"
26#include "clang/AST/DeclGroup.h"
27#include "clang/AST/DeclObjC.h"
28#include "clang/AST/DeclTemplate.h"
29#include "clang/AST/DeclarationName.h"
30#include "clang/AST/Expr.h"
31#include "clang/AST/ExprCXX.h"
32#include "clang/AST/ExternalASTSource.h"
33#include "clang/AST/NestedNameSpecifier.h"
34#include "clang/AST/OpenMPClause.h"
35#include "clang/AST/ODRHash.h"
36#include "clang/AST/RawCommentList.h"
37#include "clang/AST/TemplateBase.h"
38#include "clang/AST/TemplateName.h"
39#include "clang/AST/Type.h"
40#include "clang/AST/TypeLoc.h"
41#include "clang/AST/TypeLocVisitor.h"
42#include "clang/AST/UnresolvedSet.h"
43#include "clang/Basic/CommentOptions.h"
44#include "clang/Basic/Diagnostic.h"
45#include "clang/Basic/DiagnosticOptions.h"
46#include "clang/Basic/ExceptionSpecificationType.h"
47#include "clang/Basic/FileManager.h"
48#include "clang/Basic/FileSystemOptions.h"
49#include "clang/Basic/IdentifierTable.h"
50#include "clang/Basic/LLVM.h"
51#include "clang/Basic/LangOptions.h"
52#include "clang/Basic/Module.h"
53#include "clang/Basic/ObjCRuntime.h"
54#include "clang/Basic/OperatorKinds.h"
55#include "clang/Basic/PragmaKinds.h"
56#include "clang/Basic/Sanitizers.h"
57#include "clang/Basic/SourceLocation.h"
58#include "clang/Basic/SourceManager.h"
59#include "clang/Basic/SourceManagerInternals.h"
60#include "clang/Basic/Specifiers.h"
61#include "clang/Basic/TargetInfo.h"
62#include "clang/Basic/TargetOptions.h"
63#include "clang/Basic/TokenKinds.h"
64#include "clang/Basic/Version.h"
65#include "clang/Lex/HeaderSearch.h"
66#include "clang/Lex/HeaderSearchOptions.h"
67#include "clang/Lex/MacroInfo.h"
68#include "clang/Lex/ModuleMap.h"
69#include "clang/Lex/PreprocessingRecord.h"
70#include "clang/Lex/Preprocessor.h"
71#include "clang/Lex/PreprocessorOptions.h"
72#include "clang/Lex/Token.h"
73#include "clang/Sema/ObjCMethodList.h"
74#include "clang/Sema/Scope.h"
75#include "clang/Sema/Sema.h"
76#include "clang/Sema/Weak.h"
77#include "clang/Serialization/ASTBitCodes.h"
78#include "clang/Serialization/ASTDeserializationListener.h"
79#include "clang/Serialization/ContinuousRangeMap.h"
80#include "clang/Serialization/GlobalModuleIndex.h"
81#include "clang/Serialization/InMemoryModuleCache.h"
82#include "clang/Serialization/ModuleFile.h"
83#include "clang/Serialization/ModuleFileExtension.h"
84#include "clang/Serialization/ModuleManager.h"
85#include "clang/Serialization/PCHContainerOperations.h"
86#include "clang/Serialization/SerializationDiagnostic.h"
87#include "llvm/ADT/APFloat.h"
88#include "llvm/ADT/APInt.h"
89#include "llvm/ADT/APSInt.h"
90#include "llvm/ADT/ArrayRef.h"
91#include "llvm/ADT/DenseMap.h"
92#include "llvm/ADT/FloatingPointMode.h"
93#include "llvm/ADT/FoldingSet.h"
94#include "llvm/ADT/Hashing.h"
95#include "llvm/ADT/IntrusiveRefCntPtr.h"
96#include "llvm/ADT/None.h"
97#include "llvm/ADT/Optional.h"
98#include "llvm/ADT/STLExtras.h"
99#include "llvm/ADT/ScopeExit.h"
100#include "llvm/ADT/SmallPtrSet.h"
101#include "llvm/ADT/SmallString.h"
102#include "llvm/ADT/SmallVector.h"
103#include "llvm/ADT/StringExtras.h"
104#include "llvm/ADT/StringMap.h"
105#include "llvm/ADT/StringRef.h"
106#include "llvm/ADT/Triple.h"
107#include "llvm/ADT/iterator_range.h"
108#include "llvm/Bitstream/BitstreamReader.h"
109#include "llvm/Support/Casting.h"
110#include "llvm/Support/Compiler.h"
111#include "llvm/Support/Compression.h"
112#include "llvm/Support/DJB.h"
113#include "llvm/Support/Endian.h"
114#include "llvm/Support/Error.h"
115#include "llvm/Support/ErrorHandling.h"
116#include "llvm/Support/FileSystem.h"
117#include "llvm/Support/LEB128.h"
118#include "llvm/Support/MemoryBuffer.h"
119#include "llvm/Support/Path.h"
120#include "llvm/Support/SaveAndRestore.h"
121#include "llvm/Support/Timer.h"
122#include "llvm/Support/VersionTuple.h"
123#include "llvm/Support/raw_ostream.h"
124#include <algorithm>
125#include <cassert>
126#include <cstddef>
127#include <cstdint>
128#include <cstdio>
129#include <ctime>
130#include <iterator>
131#include <limits>
132#include <map>
133#include <memory>
134#include <string>
135#include <system_error>
136#include <tuple>
137#include <utility>
138#include <vector>

140using namespace clang;
141using namespace clang::serialization;
142using namespace clang::serialization::reader;
143using llvm::BitstreamCursor;
144using llvm::RoundingMode;

146//===----------------------------------------------------------------------===//
147// ChainedASTReaderListener implementation
148//===----------------------------------------------------------------------===//

150bool
151ChainedASTReaderListener::ReadFullVersionInformation(StringRef FullVersion) {
return First->ReadFullVersionInformation(FullVersion) ||
       Second->ReadFullVersionInformation(FullVersion);
154}

156void ChainedASTReaderListener::ReadModuleName(StringRef ModuleName) {
First->ReadModuleName(ModuleName);
Second->ReadModuleName(ModuleName);
159}

161void ChainedASTReaderListener::ReadModuleMapFile(StringRef ModuleMapPath) {
First->ReadModuleMapFile(ModuleMapPath);
Second->ReadModuleMapFile(ModuleMapPath);
164}

166bool
167ChainedASTReaderListener::ReadLanguageOptions(const LangOptions &LangOpts,
                                            bool Complain,
                                            bool AllowCompatibleDifferences) {
return First->ReadLanguageOptions(LangOpts, Complain,
                                  AllowCompatibleDifferences) ||
       Second->ReadLanguageOptions(LangOpts, Complain,
                                   AllowCompatibleDifferences);
174}

176bool ChainedASTReaderListener::ReadTargetOptions(
  const TargetOptions &TargetOpts, bool Complain,
  bool AllowCompatibleDifferences) {
return First->ReadTargetOptions(TargetOpts, Complain,
                                AllowCompatibleDifferences) ||
       Second->ReadTargetOptions(TargetOpts, Complain,
                                 AllowCompatibleDifferences);
183}

185bool ChainedASTReaderListener::ReadDiagnosticOptions(
  IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts, bool Complain) {
return First->ReadDiagnosticOptions(DiagOpts, Complain) ||
       Second->ReadDiagnosticOptions(DiagOpts, Complain);
189}

191bool
192ChainedASTReaderListener::ReadFileSystemOptions(const FileSystemOptions &FSOpts,
                                              bool Complain) {
return First->ReadFileSystemOptions(FSOpts, Complain) ||
       Second->ReadFileSystemOptions(FSOpts, Complain);
196}

198bool ChainedASTReaderListener::ReadHeaderSearchOptions(
  const HeaderSearchOptions &HSOpts, StringRef SpecificModuleCachePath,
  bool Complain) {
return First->ReadHeaderSearchOptions(HSOpts, SpecificModuleCachePath,
                                      Complain) ||
       Second->ReadHeaderSearchOptions(HSOpts, SpecificModuleCachePath,
                                       Complain);
205}

207bool ChainedASTReaderListener::ReadPreprocessorOptions(
  const PreprocessorOptions &PPOpts, bool Complain,
  std::string &SuggestedPredefines) {
return First->ReadPreprocessorOptions(PPOpts, Complain,
                                      SuggestedPredefines) ||
       Second->ReadPreprocessorOptions(PPOpts, Complain, SuggestedPredefines);
213}

215void ChainedASTReaderListener::ReadCounter(const serialization::ModuleFile &M,
                                         unsigned Value) {
First->ReadCounter(M, Value);
Second->ReadCounter(M, Value);
219}

221bool ChainedASTReaderListener::needsInputFileVisitation() {
return First->needsInputFileVisitation() ||
       Second->needsInputFileVisitation();
224}

226bool ChainedASTReaderListener::needsSystemInputFileVisitation() {
return First->needsSystemInputFileVisitation() ||
Second->needsSystemInputFileVisitation();
229}

231void ChainedASTReaderListener::visitModuleFile(StringRef Filename,
                                             ModuleKind Kind) {
First->visitModuleFile(Filename, Kind);
Second->visitModuleFile(Filename, Kind);
235}

237bool ChainedASTReaderListener::visitInputFile(StringRef Filename,
                                            bool isSystem,
                                            bool isOverridden,
                                            bool isExplicitModule) {
bool Continue = false;
if (First->needsInputFileVisitation() &&
    (!isSystem || First->needsSystemInputFileVisitation()))
  Continue |= First->visitInputFile(Filename, isSystem, isOverridden,
                                    isExplicitModule);
if (Second->needsInputFileVisitation() &&
    (!isSystem || Second->needsSystemInputFileVisitation()))
  Continue |= Second->visitInputFile(Filename, isSystem, isOverridden,
                                     isExplicitModule);
return Continue;
251}

253void ChainedASTReaderListener::readModuleFileExtension(
     const ModuleFileExtensionMetadata &Metadata) {
First->readModuleFileExtension(Metadata);
Second->readModuleFileExtension(Metadata);
257}

259//===----------------------------------------------------------------------===//
260// PCH validator implementation
261//===----------------------------------------------------------------------===//

263ASTReaderListener::~ASTReaderListener() = default;

265/// Compare the given set of language options against an existing set of
266/// language options.
267///
268/// \param Diags If non-NULL, diagnostics will be emitted via this engine.
269/// \param AllowCompatibleDifferences If true, differences between compatible
270///        language options will be permitted.
271///
272/// \returns true if the languagae options mis-match, false otherwise.
273static bool checkLanguageOptions(const LangOptions &LangOpts,
                               const LangOptions &ExistingLangOpts,
                               DiagnosticsEngine *Diags,
                               bool AllowCompatibleDifferences = true) {
277#define LANGOPT(Name, Bits, Default, Description)                 \
if (ExistingLangOpts.Name != LangOpts.Name) {                   \
  if (Diags)                                                    \
    Diags->Report(diag::err_pch_langopt_mismatch)               \
      << Description << LangOpts.Name << ExistingLangOpts.Name; \
  return true;                                                  \
}

285#define VALUE_LANGOPT(Name, Bits, Default, Description)   \
if (ExistingLangOpts.Name != LangOpts.Name) {           \
  if (Diags)                                            \
    Diags->Report(diag::err_pch_langopt_value_mismatch) \
      << Description;                                   \
  return true;                                          \
}

293#define ENUM_LANGOPT(Name, Type, Bits, Default, Description)   \
if (ExistingLangOpts.get##Name() != LangOpts.get##Name()) {  \
  if (Diags)                                                 \
    Diags->Report(diag::err_pch_langopt_value_mismatch)      \
      << Description;                                        \
  return true;                                               \
}

301#define COMPATIBLE_LANGOPT(Name, Bits, Default, Description)  \
if (!AllowCompatibleDifferences)                            \
  LANGOPT(Name, Bits, Default, Description)

305#define COMPATIBLE_ENUM_LANGOPT(Name, Bits, Default, Description)  \
if (!AllowCompatibleDifferences)                                 \
  ENUM_LANGOPT(Name, Bits, Default, Description)

309#define COMPATIBLE_VALUE_LANGOPT(Name, Bits, Default, Description) \
if (!AllowCompatibleDifferences)                                 \
  VALUE_LANGOPT(Name, Bits, Default, Description)

313#define BENIGN_LANGOPT(Name, Bits, Default, Description)
314#define BENIGN_ENUM_LANGOPT(Name, Type, Bits, Default, Description)
315#define BENIGN_VALUE_LANGOPT(Name, Type, Bits, Default, Description)
316#include "clang/Basic/LangOptions.def"

if (ExistingLangOpts.ModuleFeatures != LangOpts.ModuleFeatures) {
  if (Diags)
    Diags->Report(diag::err_pch_langopt_value_mismatch) << "module features";
  return true;
}

if (ExistingLangOpts.ObjCRuntime != LangOpts.ObjCRuntime) {
  if (Diags)
    Diags->Report(diag::err_pch_langopt_value_mismatch)
    << "target Objective-C runtime";
  return true;
}

if (ExistingLangOpts.CommentOpts.BlockCommandNames !=
    LangOpts.CommentOpts.BlockCommandNames) {
  if (Diags)
    Diags->Report(diag::err_pch_langopt_value_mismatch)
      << "block command names";
  return true;
}

// Sanitizer feature mismatches are treated as compatible differences. If
// compatible differences aren't allowed, we still only want to check for
// mismatches of non-modular sanitizers (the only ones which can affect AST
// generation).
if (!AllowCompatibleDifferences) {
  SanitizerMask ModularSanitizers = getPPTransparentSanitizers();
  SanitizerSet ExistingSanitizers = ExistingLangOpts.Sanitize;
  SanitizerSet ImportedSanitizers = LangOpts.Sanitize;
  ExistingSanitizers.clear(ModularSanitizers);
  ImportedSanitizers.clear(ModularSanitizers);
  if (ExistingSanitizers.Mask != ImportedSanitizers.Mask) {
    const std::string Flag = "-fsanitize=";
    if (Diags) {
352#define SANITIZER(NAME, ID)                                                    \
{                                                                            \
  bool InExistingModule = ExistingSanitizers.has(SanitizerKind::ID);         \
  bool InImportedModule = ImportedSanitizers.has(SanitizerKind::ID);         \
  if (InExistingModule != InImportedModule)                                  \
    Diags->Report(diag::err_pch_targetopt_feature_mismatch)                  \
        << InExistingModule << (Flag + NAME);                                \
}
360#include "clang/Basic/Sanitizers.def"
    }
    return true;
  }
}

return false;
367}

369/// Compare the given set of target options against an existing set of
370/// target options.
371///
372/// \param Diags If non-NULL, diagnostics will be emitted via this engine.
373///
374/// \returns true if the target options mis-match, false otherwise.
375static bool checkTargetOptions(const TargetOptions &TargetOpts,
                             const TargetOptions &ExistingTargetOpts,
                             DiagnosticsEngine *Diags,
                             bool AllowCompatibleDifferences = true) {
379#define CHECK_TARGET_OPT(Field, Name)                             \
if (TargetOpts.Field != ExistingTargetOpts.Field) {             \
  if (Diags)                                                    \
    Diags->Report(diag::err_pch_targetopt_mismatch)             \
      << Name << TargetOpts.Field << ExistingTargetOpts.Field;  \
  return true;                                                  \
}

// The triple and ABI must match exactly.
CHECK_TARGET_OPT(Triple, "target");
CHECK_TARGET_OPT(ABI, "target ABI");

// We can tolerate different CPUs in many cases, notably when one CPU
// supports a strict superset of another. When allowing compatible
// differences skip this check.
if (!AllowCompatibleDifferences) {
  CHECK_TARGET_OPT(CPU, "target CPU");
  CHECK_TARGET_OPT(TuneCPU, "tune CPU");
}

399#undef CHECK_TARGET_OPT

// Compare feature sets.
SmallVector<StringRef, 4> ExistingFeatures(
                                           ExistingTargetOpts.FeaturesAsWritten.begin(),
                                           ExistingTargetOpts.FeaturesAsWritten.end());
SmallVector<StringRef, 4> ReadFeatures(TargetOpts.FeaturesAsWritten.begin(),
                                       TargetOpts.FeaturesAsWritten.end());
llvm::sort(ExistingFeatures);
llvm::sort(ReadFeatures);

// We compute the set difference in both directions explicitly so that we can
// diagnose the differences differently.
SmallVector<StringRef, 4> UnmatchedExistingFeatures, UnmatchedReadFeatures;
std::set_difference(
    ExistingFeatures.begin(), ExistingFeatures.end(), ReadFeatures.begin(),
    ReadFeatures.end(), std::back_inserter(UnmatchedExistingFeatures));
std::set_difference(ReadFeatures.begin(), ReadFeatures.end(),
                    ExistingFeatures.begin(), ExistingFeatures.end(),
                    std::back_inserter(UnmatchedReadFeatures));

// If we are allowing compatible differences and the read feature set is
// a strict subset of the existing feature set, there is nothing to diagnose.
if (AllowCompatibleDifferences && UnmatchedReadFeatures.empty())
  return false;

if (Diags) {
  for (StringRef Feature : UnmatchedReadFeatures)
    Diags->Report(diag::err_pch_targetopt_feature_mismatch)
        << /* is-existing-feature */ false << Feature;
  for (StringRef Feature : UnmatchedExistingFeatures)
    Diags->Report(diag::err_pch_targetopt_feature_mismatch)
        << /* is-existing-feature */ true << Feature;
}

return !UnmatchedReadFeatures.empty() || !UnmatchedExistingFeatures.empty();
435}

437bool
438PCHValidator::ReadLanguageOptions(const LangOptions &LangOpts,
                                bool Complain,
                                bool AllowCompatibleDifferences) {
const LangOptions &ExistingLangOpts = PP.getLangOpts();
return checkLanguageOptions(LangOpts, ExistingLangOpts,
                            Complain ? &Reader.Diags : nullptr,
                            AllowCompatibleDifferences);
445}

447bool PCHValidator::ReadTargetOptions(const TargetOptions &TargetOpts,
                                   bool Complain,
                                   bool AllowCompatibleDifferences) {
const TargetOptions &ExistingTargetOpts = PP.getTargetInfo().getTargetOpts();
return checkTargetOptions(TargetOpts, ExistingTargetOpts,
                          Complain ? &Reader.Diags : nullptr,
                          AllowCompatibleDifferences);
454}

456namespace {

458using MacroDefinitionsMap =
  llvm::StringMap<std::pair<StringRef, bool /*IsUndef*/>>;
460using DeclsMap = llvm::DenseMap<DeclarationName, SmallVector<NamedDecl *, 8>>;

462} // namespace

464static bool checkDiagnosticGroupMappings(DiagnosticsEngine &StoredDiags,
                                       DiagnosticsEngine &Diags,
                                       bool Complain) {
using Level = DiagnosticsEngine::Level;

// Check current mappings for new -Werror mappings, and the stored mappings
// for cases that were explicitly mapped to *not* be errors that are now
// errors because of options like -Werror.
DiagnosticsEngine *MappingSources[] = { &Diags, &StoredDiags };

for (DiagnosticsEngine *MappingSource : MappingSources) {
  for (auto DiagIDMappingPair : MappingSource->getDiagnosticMappings()) {
    diag::kind DiagID = DiagIDMappingPair.first;
    Level CurLevel = Diags.getDiagnosticLevel(DiagID, SourceLocation());
    if (CurLevel < DiagnosticsEngine::Error)
      continue; // not significant
    Level StoredLevel =
        StoredDiags.getDiagnosticLevel(DiagID, SourceLocation());
    if (StoredLevel < DiagnosticsEngine::Error) {
      if (Complain)
        Diags.Report(diag::err_pch_diagopt_mismatch) << "-Werror=" +
            Diags.getDiagnosticIDs()->getWarningOptionForDiag(DiagID).str();
      return true;
    }
  }
}

return false;
492}

494static bool isExtHandlingFromDiagsError(DiagnosticsEngine &Diags) {
diag::Severity Ext = Diags.getExtensionHandlingBehavior();
if (Ext == diag::Severity::Warning && Diags.getWarningsAsErrors())
  return true;
return Ext >= diag::Severity::Error;
499}

501static bool checkDiagnosticMappings(DiagnosticsEngine &StoredDiags,
                                  DiagnosticsEngine &Diags,
                                  bool IsSystem, bool Complain) {
// Top-level options
if (IsSystem) {
  if (Diags.getSuppressSystemWarnings())
    return false;
  // If -Wsystem-headers was not enabled before, be conservative
  if (StoredDiags.getSuppressSystemWarnings()) {
    if (Complain)
      Diags.Report(diag::err_pch_diagopt_mismatch) << "-Wsystem-headers";
    return true;
  }
}

if (Diags.getWarningsAsErrors() && !StoredDiags.getWarningsAsErrors()) {
  if (Complain)
    Diags.Report(diag::err_pch_diagopt_mismatch) << "-Werror";
  return true;
}

if (Diags.getWarningsAsErrors() && Diags.getEnableAllWarnings() &&
    !StoredDiags.getEnableAllWarnings()) {
  if (Complain)
    Diags.Report(diag::err_pch_diagopt_mismatch) << "-Weverything -Werror";
  return true;
}

if (isExtHandlingFromDiagsError(Diags) &&
    !isExtHandlingFromDiagsError(StoredDiags)) {
  if (Complain)
    Diags.Report(diag::err_pch_diagopt_mismatch) << "-pedantic-errors";
  return true;
}

return checkDiagnosticGroupMappings(StoredDiags, Diags, Complain);
537}

539/// Return the top import module if it is implicit, nullptr otherwise.
540static Module *getTopImportImplicitModule(ModuleManager &ModuleMgr,
                                        Preprocessor &PP) {
// If the original import came from a file explicitly generated by the user,
// don't check the diagnostic mappings.
// FIXME: currently this is approximated by checking whether this is not a
// module import of an implicitly-loaded module file.
// Note: ModuleMgr.rbegin() may not be the current module, but it must be in
// the transitive closure of its imports, since unrelated modules cannot be
// imported until after this module finishes validation.
ModuleFile *TopImport = &*ModuleMgr.rbegin();
while (!TopImport->ImportedBy.empty())
  TopImport = TopImport->ImportedBy[0];
if (TopImport->Kind != MK_ImplicitModule)
  return nullptr;

StringRef ModuleName = TopImport->ModuleName;
assert(!ModuleName.empty() && "diagnostic options read before module name")((void)0);

Module *M = PP.getHeaderSearchInfo().lookupModule(ModuleName);
assert(M && "missing module")((void)0);
return M;
561}

563bool PCHValidator::ReadDiagnosticOptions(
  IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts, bool Complain) {
DiagnosticsEngine &ExistingDiags = PP.getDiagnostics();
IntrusiveRefCntPtr<DiagnosticIDs> DiagIDs(ExistingDiags.getDiagnosticIDs());
IntrusiveRefCntPtr<DiagnosticsEngine> Diags(
    new DiagnosticsEngine(DiagIDs, DiagOpts.get()));
// This should never fail, because we would have processed these options
// before writing them to an ASTFile.
ProcessWarningOptions(*Diags, *DiagOpts, /*Report*/false);

ModuleManager &ModuleMgr = Reader.getModuleManager();
assert(ModuleMgr.size() >= 1 && "what ASTFile is this then")((void)0);

Module *TopM = getTopImportImplicitModule(ModuleMgr, PP);
if (!TopM)
  return false;

// FIXME: if the diagnostics are incompatible, save a DiagnosticOptions that
// contains the union of their flags.
return checkDiagnosticMappings(*Diags, ExistingDiags, TopM->IsSystem,
                               Complain);
584}

586/// Collect the macro definitions provided by the given preprocessor
587/// options.
588static void
589collectMacroDefinitions(const PreprocessorOptions &PPOpts,
                      MacroDefinitionsMap &Macros,
                      SmallVectorImpl<StringRef> *MacroNames = nullptr) {
for (unsigned I = 0, N = PPOpts.Macros.size(); I != N; ++I) {
  StringRef Macro = PPOpts.Macros[I].first;
  bool IsUndef = PPOpts.Macros[I].second;

  std::pair<StringRef, StringRef> MacroPair = Macro.split('=');
  StringRef MacroName = MacroPair.first;
  StringRef MacroBody = MacroPair.second;

  // For an #undef'd macro, we only care about the name.
  if (IsUndef) {
    if (MacroNames && !Macros.count(MacroName))
      MacroNames->push_back(MacroName);

    Macros[MacroName] = std::make_pair("", true);
    continue;
  }

  // For a #define'd macro, figure out the actual definition.
  if (MacroName.size() == Macro.size())
    MacroBody = "1";
  else {
    // Note: GCC drops anything following an end-of-line character.
    StringRef::size_type End = MacroBody.find_first_of("\n\r");
    MacroBody = MacroBody.substr(0, End);
  }

  if (MacroNames && !Macros.count(MacroName))
    MacroNames->push_back(MacroName);
  Macros[MacroName] = std::make_pair(MacroBody, false);
}
622}

624/// Check the preprocessor options deserialized from the control block
625/// against the preprocessor options in an existing preprocessor.
626///
627/// \param Diags If non-null, produce diagnostics for any mismatches incurred.
628/// \param Validate If true, validate preprocessor options. If false, allow
629///        macros defined by \p ExistingPPOpts to override those defined by
630///        \p PPOpts in SuggestedPredefines.
631static bool checkPreprocessorOptions(const PreprocessorOptions &PPOpts,
                                   const PreprocessorOptions &ExistingPPOpts,
                                   DiagnosticsEngine *Diags,
                                   FileManager &FileMgr,
                                   std::string &SuggestedPredefines,
                                   const LangOptions &LangOpts,
                                   bool Validate = true) {
// Check macro definitions.
MacroDefinitionsMap ASTFileMacros;
collectMacroDefinitions(PPOpts, ASTFileMacros);
MacroDefinitionsMap ExistingMacros;
SmallVector<StringRef, 4> ExistingMacroNames;
collectMacroDefinitions(ExistingPPOpts, ExistingMacros, &ExistingMacroNames);

for (unsigned I = 0, N = ExistingMacroNames.size(); I != N; ++I) {
  // Dig out the macro definition in the existing preprocessor options.
  StringRef MacroName = ExistingMacroNames[I];
  std::pair<StringRef, bool> Existing = ExistingMacros[MacroName];

  // Check whether we know anything about this macro name or not.
  llvm::StringMap<std::pair<StringRef, bool /*IsUndef*/>>::iterator Known =
      ASTFileMacros.find(MacroName);
  if (!Validate || Known == ASTFileMacros.end()) {
    // FIXME: Check whether this identifier was referenced anywhere in the
    // AST file. If so, we should reject the AST file. Unfortunately, this
    // information isn't in the control block. What shall we do about it?

    if (Existing.second) {
      SuggestedPredefines += "#undef ";
      SuggestedPredefines += MacroName.str();
      SuggestedPredefines += '\n';
    } else {
      SuggestedPredefines += "#define ";
      SuggestedPredefines += MacroName.str();
      SuggestedPredefines += ' ';
      SuggestedPredefines += Existing.first.str();
      SuggestedPredefines += '\n';
    }
    continue;
  }

  // If the macro was defined in one but undef'd in the other, we have a
  // conflict.
  if (Existing.second != Known->second.second) {
    if (Diags) {
      Diags->Report(diag::err_pch_macro_def_undef)
        << MacroName << Known->second.second;
    }
    return true;
  }

  // If the macro was #undef'd in both, or if the macro bodies are identical,
  // it's fine.
  if (Existing.second || Existing.first == Known->second.first)
    continue;

  // The macro bodies differ; complain.
  if (Diags) {
    Diags->Report(diag::err_pch_macro_def_conflict)
      << MacroName << Known->second.first << Existing.first;
  }
  return true;
}

// Check whether we're using predefines.
if (PPOpts.UsePredefines != ExistingPPOpts.UsePredefines && Validate) {
  if (Diags) {
    Diags->Report(diag::err_pch_undef) << ExistingPPOpts.UsePredefines;
  }
  return true;
}

// Detailed record is important since it is used for the module cache hash.
if (LangOpts.Modules &&
    PPOpts.DetailedRecord != ExistingPPOpts.DetailedRecord && Validate) {
  if (Diags) {
    Diags->Report(diag::err_pch_pp_detailed_record) << PPOpts.DetailedRecord;
  }
  return true;
}

// Compute the #include and #include_macros lines we need.
for (unsigned I = 0, N = ExistingPPOpts.Includes.size(); I != N; ++I) {
  StringRef File = ExistingPPOpts.Includes[I];

  if (!ExistingPPOpts.ImplicitPCHInclude.empty() &&
      !ExistingPPOpts.PCHThroughHeader.empty()) {
    // In case the through header is an include, we must add all the includes
    // to the predefines so the start point can be determined.
    SuggestedPredefines += "#include \"";
    SuggestedPredefines += File;
    SuggestedPredefines += "\"\n";
    continue;
  }

  if (File == ExistingPPOpts.ImplicitPCHInclude)
    continue;

  if (std::find(PPOpts.Includes.begin(), PPOpts.Includes.end(), File)
        != PPOpts.Includes.end())
    continue;

  SuggestedPredefines += "#include \"";
  SuggestedPredefines += File;
  SuggestedPredefines += "\"\n";
}

for (unsigned I = 0, N = ExistingPPOpts.MacroIncludes.size(); I != N; ++I) {
  StringRef File = ExistingPPOpts.MacroIncludes[I];
  if (std::find(PPOpts.MacroIncludes.begin(), PPOpts.MacroIncludes.end(),
                File)
      != PPOpts.MacroIncludes.end())
    continue;

  SuggestedPredefines += "#__include_macros \"";
  SuggestedPredefines += File;
  SuggestedPredefines += "\"\n##\n";
}

return false;
751}

753bool PCHValidator::ReadPreprocessorOptions(const PreprocessorOptions &PPOpts,
                                         bool Complain,
                                         std::string &SuggestedPredefines) {
const PreprocessorOptions &ExistingPPOpts = PP.getPreprocessorOpts();

return checkPreprocessorOptions(PPOpts, ExistingPPOpts,
                                Complain? &Reader.Diags : nullptr,
                                PP.getFileManager(),
                                SuggestedPredefines,
                                PP.getLangOpts());
763}

765bool SimpleASTReaderListener::ReadPreprocessorOptions(
                                const PreprocessorOptions &PPOpts,
                                bool Complain,
                                std::string &SuggestedPredefines) {
return checkPreprocessorOptions(PPOpts,
                                PP.getPreprocessorOpts(),
                                nullptr,
                                PP.getFileManager(),
                                SuggestedPredefines,
                                PP.getLangOpts(),
                                false);
776}

778/// Check the header search options deserialized from the control block
779/// against the header search options in an existing preprocessor.
780///
781/// \param Diags If non-null, produce diagnostics for any mismatches incurred.
782static bool checkHeaderSearchOptions(const HeaderSearchOptions &HSOpts,
                                   StringRef SpecificModuleCachePath,
                                   StringRef ExistingModuleCachePath,
                                   DiagnosticsEngine *Diags,
                                   const LangOptions &LangOpts,
                                   const PreprocessorOptions &PPOpts) {
if (LangOpts.Modules) {
  if (SpecificModuleCachePath != ExistingModuleCachePath &&
      !PPOpts.AllowPCHWithDifferentModulesCachePath) {
    if (Diags)
      Diags->Report(diag::err_pch_modulecache_mismatch)
        << SpecificModuleCachePath << ExistingModuleCachePath;
    return true;
  }
}

return false;
799}

801bool PCHValidator::ReadHeaderSearchOptions(const HeaderSearchOptions &HSOpts,
                                         StringRef SpecificModuleCachePath,
                                         bool Complain) {
return checkHeaderSearchOptions(HSOpts, SpecificModuleCachePath,
                                PP.getHeaderSearchInfo().getModuleCachePath(),
                                Complain ? &Reader.Diags : nullptr,
                                PP.getLangOpts(), PP.getPreprocessorOpts());
808}

810void PCHValidator::ReadCounter(const ModuleFile &M, unsigned Value) {
PP.setCounterValue(Value);
812}

814//===----------------------------------------------------------------------===//
815// AST reader implementation
816//===----------------------------------------------------------------------===//

818static uint64_t readULEB(const unsigned char *&P) {
unsigned Length = 0;
const char *Error = nullptr;

uint64_t Val = llvm::decodeULEB128(P, &Length, nullptr, &Error);
if (Error)
  llvm::report_fatal_error(Error);
P += Length;
return Val;
827}

829/// Read ULEB-encoded key length and data length.
830static std::pair<unsigned, unsigned>
831readULEBKeyDataLength(const unsigned char *&P) {
unsigned KeyLen = readULEB(P);
if ((unsigned)KeyLen != KeyLen)
  llvm::report_fatal_error("key too large");

unsigned DataLen = readULEB(P);
if ((unsigned)DataLen != DataLen)
  llvm::report_fatal_error("data too large");

return std::make_pair(KeyLen, DataLen);
841}

843void ASTReader::setDeserializationListener(ASTDeserializationListener *Listener,
                                         bool TakeOwnership) {
DeserializationListener = Listener;
OwnsDeserializationListener = TakeOwnership;
847}

849unsigned ASTSelectorLookupTrait::ComputeHash(Selector Sel) {
return serialization::ComputeHash(Sel);
851}

853std::pair<unsigned, unsigned>
854ASTSelectorLookupTrait::ReadKeyDataLength(const unsigned char*& d) {
return readULEBKeyDataLength(d);
856}

858ASTSelectorLookupTrait::internal_key_type
859ASTSelectorLookupTrait::ReadKey(const unsigned char* d, unsigned) {
using namespace llvm::support;

SelectorTable &SelTable = Reader.getContext().Selectors;
unsigned N = endian::readNext<uint16_t, little, unaligned>(d);
IdentifierInfo *FirstII = Reader.getLocalIdentifier(
    F, endian::readNext<uint32_t, little, unaligned>(d));
if (N == 0)
  return SelTable.getNullarySelector(FirstII);
else if (N == 1)
  return SelTable.getUnarySelector(FirstII);

SmallVector<IdentifierInfo *, 16> Args;
Args.push_back(FirstII);
for (unsigned I = 1; I != N; ++I)
  Args.push_back(Reader.getLocalIdentifier(
      F, endian::readNext<uint32_t, little, unaligned>(d)));

return SelTable.getSelector(N, Args.data());
878}

880ASTSelectorLookupTrait::data_type
881ASTSelectorLookupTrait::ReadData(Selector, const unsigned char* d,
                               unsigned DataLen) {
using namespace llvm::support;

data_type Result;

Result.ID = Reader.getGlobalSelectorID(
    F, endian::readNext<uint32_t, little, unaligned>(d));
unsigned FullInstanceBits = endian::readNext<uint16_t, little, unaligned>(d);
unsigned FullFactoryBits = endian::readNext<uint16_t, little, unaligned>(d);
Result.InstanceBits = FullInstanceBits & 0x3;
Result.InstanceHasMoreThanOneDecl = (FullInstanceBits >> 2) & 0x1;
Result.FactoryBits = FullFactoryBits & 0x3;
Result.FactoryHasMoreThanOneDecl = (FullFactoryBits >> 2) & 0x1;
unsigned NumInstanceMethods = FullInstanceBits >> 3;
unsigned NumFactoryMethods = FullFactoryBits >> 3;

// Load instance methods
for (unsigned I = 0; I != NumInstanceMethods; ++I) {
  if (ObjCMethodDecl *Method = Reader.GetLocalDeclAs<ObjCMethodDecl>(
          F, endian::readNext<uint32_t, little, unaligned>(d)))
    Result.Instance.push_back(Method);
}

// Load factory methods
for (unsigned I = 0; I != NumFactoryMethods; ++I) {
  if (ObjCMethodDecl *Method = Reader.GetLocalDeclAs<ObjCMethodDecl>(
          F, endian::readNext<uint32_t, little, unaligned>(d)))
    Result.Factory.push_back(Method);
}

return Result;
913}

915unsigned ASTIdentifierLookupTraitBase::ComputeHash(const internal_key_type& a) {
return llvm::djbHash(a);
917}

919std::pair<unsigned, unsigned>
920ASTIdentifierLookupTraitBase::ReadKeyDataLength(const unsigned char*& d) {
return readULEBKeyDataLength(d);
922}

924ASTIdentifierLookupTraitBase::internal_key_type
925ASTIdentifierLookupTraitBase::ReadKey(const unsigned char* d, unsigned n) {
assert(n >= 2 && d[n-1] == '\0')((void)0);
return StringRef((const char*) d, n-1);
928}

930/// Whether the given identifier is "interesting".
931static bool isInterestingIdentifier(ASTReader &Reader, IdentifierInfo &II,
                                  bool IsModule) {
return II.hadMacroDefinition() || II.isPoisoned() ||
       (!IsModule && II.getObjCOrBuiltinID()) ||
       II.hasRevertedTokenIDToIdentifier() ||
       (!(IsModule && Reader.getPreprocessor().getLangOpts().CPlusPlus) &&
        II.getFETokenInfo());
938}

940static bool readBit(unsigned &Bits) {
bool Value = Bits & 0x1;
Bits >>= 1;
return Value;
944}

946IdentID ASTIdentifierLookupTrait::ReadIdentifierID(const unsigned char *d) {
using namespace llvm::support;

unsigned RawID = endian::readNext<uint32_t, little, unaligned>(d);
return Reader.getGlobalIdentifierID(F, RawID >> 1);
951}

953static void markIdentifierFromAST(ASTReader &Reader, IdentifierInfo &II) {
if (!II.isFromAST()) {
  II.setIsFromAST();
  bool IsModule = Reader.getPreprocessor().getCurrentModule() != nullptr;
  if (isInterestingIdentifier(Reader, II, IsModule))
    II.setChangedSinceDeserialization();
}
960}

962IdentifierInfo *ASTIdentifierLookupTrait::ReadData(const internal_key_type& k,
                                                 const unsigned char* d,
                                                 unsigned DataLen) {
using namespace llvm::support;

unsigned RawID = endian::readNext<uint32_t, little, unaligned>(d);
bool IsInteresting = RawID & 0x01;

// Wipe out the "is interesting" bit.
RawID = RawID >> 1;

// Build the IdentifierInfo and link the identifier ID with it.
IdentifierInfo *II = KnownII;
if (!II) {
  II = &Reader.getIdentifierTable().getOwn(k);
  KnownII = II;
}
markIdentifierFromAST(Reader, *II);
Reader.markIdentifierUpToDate(II);

IdentID ID = Reader.getGlobalIdentifierID(F, RawID);
if (!IsInteresting) {
  // For uninteresting identifiers, there's nothing else to do. Just notify
  // the reader that we've finished loading this identifier.
  Reader.SetIdentifierInfo(ID, II);
  return II;
}

unsigned ObjCOrBuiltinID = endian::readNext<uint16_t, little, unaligned>(d);
unsigned Bits = endian::readNext<uint16_t, little, unaligned>(d);
bool CPlusPlusOperatorKeyword = readBit(Bits);
bool HasRevertedTokenIDToIdentifier = readBit(Bits);
bool Poisoned = readBit(Bits);
bool ExtensionToken = readBit(Bits);
bool HadMacroDefinition = readBit(Bits);

assert(Bits == 0 && "Extra bits in the identifier?")((void)0);
DataLen -= 8;

// Set or check the various bits in the IdentifierInfo structure.
// Token IDs are read-only.
if (HasRevertedTokenIDToIdentifier && II->getTokenID() != tok::identifier)
  II->revertTokenIDToIdentifier();
if (!F.isModule())
  II->setObjCOrBuiltinID(ObjCOrBuiltinID);
assert(II->isExtensionToken() == ExtensionToken &&((void)0)
       "Incorrect extension token flag")((void)0);
(void)ExtensionToken;
if (Poisoned)
  II->setIsPoisoned(true);
assert(II->isCPlusPlusOperatorKeyword() == CPlusPlusOperatorKeyword &&((void)0)
       "Incorrect C++ operator keyword flag")((void)0);
(void)CPlusPlusOperatorKeyword;

// If this identifier is a macro, deserialize the macro
// definition.
if (HadMacroDefinition) {
  uint32_t MacroDirectivesOffset =
      endian::readNext<uint32_t, little, unaligned>(d);
  DataLen -= 4;

  Reader.addPendingMacro(II, &F, MacroDirectivesOffset);
}

Reader.SetIdentifierInfo(ID, II);

// Read all of the declarations visible at global scope with this
// name.
if (DataLen > 0) {
  SmallVector<uint32_t, 4> DeclIDs;
  for (; DataLen > 0; DataLen -= 4)
    DeclIDs.push_back(Reader.getGlobalDeclID(
        F, endian::readNext<uint32_t, little, unaligned>(d)));
  Reader.SetGloballyVisibleDecls(II, DeclIDs);
}

return II;
1039}

1041DeclarationNameKey::DeclarationNameKey(DeclarationName Name)
  : Kind(Name.getNameKind()) {
switch (Kind) {
case DeclarationName::Identifier:
  Data = (uint64_t)Name.getAsIdentifierInfo();
  break;
case DeclarationName::ObjCZeroArgSelector:
case DeclarationName::ObjCOneArgSelector:
case DeclarationName::ObjCMultiArgSelector:
  Data = (uint64_t)Name.getObjCSelector().getAsOpaquePtr();
  break;
case DeclarationName::CXXOperatorName:
  Data = Name.getCXXOverloadedOperator();
  break;
case DeclarationName::CXXLiteralOperatorName:
  Data = (uint64_t)Name.getCXXLiteralIdentifier();
  break;
case DeclarationName::CXXDeductionGuideName:
  Data = (uint64_t)Name.getCXXDeductionGuideTemplate()
             ->getDeclName().getAsIdentifierInfo();
  break;
case DeclarationName::CXXConstructorName:
case DeclarationName::CXXDestructorName:
case DeclarationName::CXXConversionFunctionName:
case DeclarationName::CXXUsingDirective:
  Data = 0;
  break;
}
1069}

1071unsigned DeclarationNameKey::getHash() const {
llvm::FoldingSetNodeID ID;
ID.AddInteger(Kind);

switch (Kind) {
case DeclarationName::Identifier:
case DeclarationName::CXXLiteralOperatorName:
case DeclarationName::CXXDeductionGuideName:
  ID.AddString(((IdentifierInfo*)Data)->getName());
  break;
case DeclarationName::ObjCZeroArgSelector:
case DeclarationName::ObjCOneArgSelector:
case DeclarationName::ObjCMultiArgSelector:
  ID.AddInteger(serialization::ComputeHash(Selector(Data)));
  break;
case DeclarationName::CXXOperatorName:
  ID.AddInteger((OverloadedOperatorKind)Data);
  break;
case DeclarationName::CXXConstructorName:
case DeclarationName::CXXDestructorName:
case DeclarationName::CXXConversionFunctionName:
case DeclarationName::CXXUsingDirective:
  break;
}

return ID.ComputeHash();
1097}

1099ModuleFile *
1100ASTDeclContextNameLookupTrait::ReadFileRef(const unsigned char *&d) {
using namespace llvm::support;

uint32_t ModuleFileID = endian::readNext<uint32_t, little, unaligned>(d);
return Reader.getLocalModuleFile(F, ModuleFileID);
1105}

1107std::pair<unsigned, unsigned>
1108ASTDeclContextNameLookupTrait::ReadKeyDataLength(const unsigned char *&d) {
return readULEBKeyDataLength(d);
1110}

1112ASTDeclContextNameLookupTrait::internal_key_type
1113ASTDeclContextNameLookupTrait::ReadKey(const unsigned char *d, unsigned) {
using namespace llvm::support;

auto Kind = (DeclarationName::NameKind)*d++;
uint64_t Data;
switch (Kind) {
case DeclarationName::Identifier:
case DeclarationName::CXXLiteralOperatorName:
case DeclarationName::CXXDeductionGuideName:
  Data = (uint64_t)Reader.getLocalIdentifier(
      F, endian::readNext<uint32_t, little, unaligned>(d));
  break;
case DeclarationName::ObjCZeroArgSelector:
case DeclarationName::ObjCOneArgSelector:
case DeclarationName::ObjCMultiArgSelector:
  Data =
      (uint64_t)Reader.getLocalSelector(
                           F, endian::readNext<uint32_t, little, unaligned>(
                                  d)).getAsOpaquePtr();
  break;
case DeclarationName::CXXOperatorName:
  Data = *d++; // OverloadedOperatorKind
  break;
case DeclarationName::CXXConstructorName:
case DeclarationName::CXXDestructorName:
case DeclarationName::CXXConversionFunctionName:
case DeclarationName::CXXUsingDirective:
  Data = 0;
  break;
}

return DeclarationNameKey(Kind, Data);
1145}

1147void ASTDeclContextNameLookupTrait::ReadDataInto(internal_key_type,
                                               const unsigned char *d,
                                               unsigned DataLen,
                                               data_type_builder &Val) {
using namespace llvm::support;

for (unsigned NumDecls = DataLen / 4; NumDecls; --NumDecls) {
  uint32_t LocalID = endian::readNext<uint32_t, little, unaligned>(d);
  Val.insert(Reader.getGlobalDeclID(F, LocalID));
}
1157}

1159bool ASTReader::ReadLexicalDeclContextStorage(ModuleFile &M,
                                            BitstreamCursor &Cursor,
                                            uint64_t Offset,
                                            DeclContext *DC) {
assert(Offset != 0)((void)0);

SavedStreamPosition SavedPosition(Cursor);
if (llvm::Error Err = Cursor.JumpToBit(Offset)) {
  Error(std::move(Err));
  return true;
}

RecordData Record;
StringRef Blob;
Expected<unsigned> MaybeCode = Cursor.ReadCode();
if (!MaybeCode) {
  Error(MaybeCode.takeError());
  return true;
}
unsigned Code = MaybeCode.get();

Expected<unsigned> MaybeRecCode = Cursor.readRecord(Code, Record, &Blob);
if (!MaybeRecCode) {
  Error(MaybeRecCode.takeError());
  return true;
}
unsigned RecCode = MaybeRecCode.get();
if (RecCode != DECL_CONTEXT_LEXICAL) {
  Error("Expected lexical block");
  return true;
}

assert(!isa<TranslationUnitDecl>(DC) &&((void)0)
       "expected a TU_UPDATE_LEXICAL record for TU")((void)0);
// If we are handling a C++ class template instantiation, we can see multiple
// lexical updates for the same record. It's important that we select only one
// of them, so that field numbering works properly. Just pick the first one we
// see.
auto &Lex = LexicalDecls[DC];
if (!Lex.first) {
  Lex = std::make_pair(
      &M, llvm::makeArrayRef(
              reinterpret_cast<const llvm::support::unaligned_uint32_t *>(
                  Blob.data()),
              Blob.size() / 4));
}
DC->setHasExternalLexicalStorage(true);
return false;
1207}

1209bool ASTReader::ReadVisibleDeclContextStorage(ModuleFile &M,
                                            BitstreamCursor &Cursor,
                                            uint64_t Offset,
                                            DeclID ID) {
assert(Offset != 0)((void)0);

SavedStreamPosition SavedPosition(Cursor);
if (llvm::Error Err = Cursor.JumpToBit(Offset)) {
  Error(std::move(Err));
  return true;
}

RecordData Record;
StringRef Blob;
Expected<unsigned> MaybeCode = Cursor.ReadCode();
if (!MaybeCode) {
  Error(MaybeCode.takeError());
  return true;
}
unsigned Code = MaybeCode.get();

Expected<unsigned> MaybeRecCode = Cursor.readRecord(Code, Record, &Blob);
if (!MaybeRecCode) {
  Error(MaybeRecCode.takeError());
  return true;
}
unsigned RecCode = MaybeRecCode.get();
if (RecCode != DECL_CONTEXT_VISIBLE) {
  Error("Expected visible lookup table block");
  return true;
}

// We can't safely determine the primary context yet, so delay attaching the
// lookup table until we're done with recursive deserialization.
auto *Data = (const unsigned char*)Blob.data();
PendingVisibleUpdates[ID].push_back(PendingVisibleUpdate{&M, Data});
return false;
1246}

1248void ASTReader::Error(StringRef Msg) const {
Error(diag::err_fe_pch_malformed, Msg);
if (PP.getLangOpts().Modules && !Diags.isDiagnosticInFlight() &&
    !PP.getHeaderSearchInfo().getModuleCachePath().empty()) {
  Diag(diag::note_module_cache_path)
    << PP.getHeaderSearchInfo().getModuleCachePath();
}
1255}

1257void ASTReader::Error(unsigned DiagID, StringRef Arg1, StringRef Arg2,
                    StringRef Arg3) const {
if (Diags.isDiagnosticInFlight())
  Diags.SetDelayedDiagnostic(DiagID, Arg1, Arg2, Arg3);
else
  Diag(DiagID) << Arg1 << Arg2 << Arg3;
1263}

1265void ASTReader::Error(llvm::Error &&Err) const {
Error(toString(std::move(Err)));
1267}

1269//===----------------------------------------------------------------------===//
1270// Source Manager Deserialization
1271//===----------------------------------------------------------------------===//

1273/// Read the line table in the source manager block.
1274/// \returns true if there was an error.
1275bool ASTReader::ParseLineTable(ModuleFile &F,
                             const RecordData &Record) {
unsigned Idx = 0;
LineTableInfo &LineTable = SourceMgr.getLineTable();

// Parse the file names
std::map<int, int> FileIDs;
FileIDs[-1] = -1; // For unspecified filenames.
for (unsigned I = 0; Record[Idx]; ++I) {
  // Extract the file name
  auto Filename = ReadPath(F, Record, Idx);
  FileIDs[I] = LineTable.getLineTableFilenameID(Filename);
}
++Idx;

// Parse the line entries
std::vector<LineEntry> Entries;
while (Idx < Record.size()) {
  int FID = Record[Idx++];
  assert(FID >= 0 && "Serialized line entries for non-local file.")((void)0);
  // Remap FileID from 1-based old view.
  FID += F.SLocEntryBaseID - 1;

  // Extract the line entries
  unsigned NumEntries = Record[Idx++];
  assert(NumEntries && "no line entries for file ID")((void)0);
  Entries.clear();
  Entries.reserve(NumEntries);
  for (unsigned I = 0; I != NumEntries; ++I) {
    unsigned FileOffset = Record[Idx++];
    unsigned LineNo = Record[Idx++];
    int FilenameID = FileIDs[Record[Idx++]];
    SrcMgr::CharacteristicKind FileKind
      = (SrcMgr::CharacteristicKind)Record[Idx++];
    unsigned IncludeOffset = Record[Idx++];
    Entries.push_back(LineEntry::get(FileOffset, LineNo, FilenameID,
                                     FileKind, IncludeOffset));
  }
  LineTable.AddEntry(FileID::get(FID), Entries);
}

return false;
1317}

1319/// Read a source manager block
1320bool ASTReader::ReadSourceManagerBlock(ModuleFile &F) {
using namespace SrcMgr;

BitstreamCursor &SLocEntryCursor = F.SLocEntryCursor;

// Set the source-location entry cursor to the current position in
// the stream. This cursor will be used to read the contents of the
// source manager block initially, and then lazily read
// source-location entries as needed.
SLocEntryCursor = F.Stream;

// The stream itself is going to skip over the source manager block.
if (llvm::Error Err = F.Stream.SkipBlock()) {
  Error(std::move(Err));
  return true;
}

// Enter the source manager block.
if (llvm::Error Err =
        SLocEntryCursor.EnterSubBlock(SOURCE_MANAGER_BLOCK_ID)) {
  Error(std::move(Err));
  return true;
}
F.SourceManagerBlockStartOffset = SLocEntryCursor.GetCurrentBitNo();

RecordData Record;
while (true) {
  Expected<llvm::BitstreamEntry> MaybeE =
      SLocEntryCursor.advanceSkippingSubblocks();
  if (!MaybeE) {
    Error(MaybeE.takeError());
    return true;
  }
  llvm::BitstreamEntry E = MaybeE.get();

  switch (E.Kind) {
  case llvm::BitstreamEntry::SubBlock: // Handled for us already.
  case llvm::BitstreamEntry::Error:
    Error("malformed block record in AST file");
    return true;
  case llvm::BitstreamEntry::EndBlock:
    return false;
  case llvm::BitstreamEntry::Record:
    // The interesting case.
    break;
  }

  // Read a record.
  Record.clear();
  StringRef Blob;
  Expected<unsigned> MaybeRecord =
      SLocEntryCursor.readRecord(E.ID, Record, &Blob);
  if (!MaybeRecord) {
    Error(MaybeRecord.takeError());
    return true;
  }
  switch (MaybeRecord.get()) {
  default:  // Default behavior: ignore.
    break;

  case SM_SLOC_FILE_ENTRY:
  case SM_SLOC_BUFFER_ENTRY:
  case SM_SLOC_EXPANSION_ENTRY:
    // Once we hit one of the source location entries, we're done.
    return false;
  }
}
1387}

1389/// If a header file is not found at the path that we expect it to be
1390/// and the PCH file was moved from its original location, try to resolve the
1391/// file by assuming that header+PCH were moved together and the header is in
1392/// the same place relative to the PCH.
1393static std::string
1394resolveFileRelativeToOriginalDir(const std::string &Filename,
                               const std::string &OriginalDir,
                               const std::string &CurrDir) {
assert(OriginalDir != CurrDir &&((void)0)
       "No point trying to resolve the file if the PCH dir didn't change")((void)0);

using namespace llvm::sys;

SmallString<128> filePath(Filename);
fs::make_absolute(filePath);
assert(path::is_absolute(OriginalDir))((void)0);
SmallString<128> currPCHPath(CurrDir);

path::const_iterator fileDirI = path::begin(path::parent_path(filePath)),
                     fileDirE = path::end(path::parent_path(filePath));
path::const_iterator origDirI = path::begin(OriginalDir),
                     origDirE = path::end(OriginalDir);
// Skip the common path components from filePath and OriginalDir.
while (fileDirI != fileDirE && origDirI != origDirE &&
       *fileDirI == *origDirI) {
  ++fileDirI;
  ++origDirI;
}
for (; origDirI != origDirE; ++origDirI)
  path::append(currPCHPath, "..");
path::append(currPCHPath, fileDirI, fileDirE);
path::append(currPCHPath, path::filename(Filename));
return std::string(currPCHPath.str());
1422}

1424bool ASTReader::ReadSLocEntry(int ID) {
if (ID == 0)
  return false;

if (unsigned(-ID) - 2 >= getTotalNumSLocs() || ID > 0) {
  Error("source location entry ID out-of-range for AST file");
  return true;
}

// Local helper to read the (possibly-compressed) buffer data following the
// entry record.
auto ReadBuffer = [this](
    BitstreamCursor &SLocEntryCursor,
    StringRef Name) -> std::unique_ptr<llvm::MemoryBuffer> {
  RecordData Record;
  StringRef Blob;
  Expected<unsigned> MaybeCode = SLocEntryCursor.ReadCode();
  if (!MaybeCode) {
    Error(MaybeCode.takeError());
    return nullptr;
  }
  unsigned Code = MaybeCode.get();

  Expected<unsigned> MaybeRecCode =
      SLocEntryCursor.readRecord(Code, Record, &Blob);
  if (!MaybeRecCode) {
    Error(MaybeRecCode.takeError());
    return nullptr;
  }
  unsigned RecCode = MaybeRecCode.get();

  if (RecCode == SM_SLOC_BUFFER_BLOB_COMPRESSED) {
    if (!llvm::zlib::isAvailable()) {
      Error("zlib is not available");
      return nullptr;
    }
    SmallString<0> Uncompressed;
    if (llvm::Error E =
            llvm::zlib::uncompress(Blob, Uncompressed, Record[0])) {
      Error("could not decompress embedded file contents: " +
            llvm::toString(std::move(E)));
      return nullptr;
    }
    return llvm::MemoryBuffer::getMemBufferCopy(Uncompressed, Name);
  } else if (RecCode == SM_SLOC_BUFFER_BLOB) {
    return llvm::MemoryBuffer::getMemBuffer(Blob.drop_back(1), Name, true);
  } else {
    Error("AST record has invalid code");
    return nullptr;
  }
};

ModuleFile *F = GlobalSLocEntryMap.find(-ID)->second;
if (llvm::Error Err = F->SLocEntryCursor.JumpToBit(
        F->SLocEntryOffsetsBase +
        F->SLocEntryOffsets[ID - F->SLocEntryBaseID])) {
  Error(std::move(Err));
  return true;
}

BitstreamCursor &SLocEntryCursor = F->SLocEntryCursor;
SourceLocation::UIntTy BaseOffset = F->SLocEntryBaseOffset;

++NumSLocEntriesRead;
Expected<llvm::BitstreamEntry> MaybeEntry = SLocEntryCursor.advance();
if (!MaybeEntry) {
  Error(MaybeEntry.takeError());
  return true;
}
llvm::BitstreamEntry Entry = MaybeEntry.get();

if (Entry.Kind != llvm::BitstreamEntry::Record) {
  Error("incorrectly-formatted source location entry in AST file");
  return true;
}

RecordData Record;
StringRef Blob;
Expected<unsigned> MaybeSLOC =
    SLocEntryCursor.readRecord(Entry.ID, Record, &Blob);
if (!MaybeSLOC) {
  Error(MaybeSLOC.takeError());
  return true;
}
switch (MaybeSLOC.get()) {
default:
  Error("incorrectly-formatted source location entry in AST file");
  return true;

case SM_SLOC_FILE_ENTRY: {
  // We will detect whether a file changed and return 'Failure' for it, but
  // we will also try to fail gracefully by setting up the SLocEntry.
  unsigned InputID = Record[4];
  InputFile IF = getInputFile(*F, InputID);
  Optional<FileEntryRef> File = IF.getFile();
  bool OverriddenBuffer = IF.isOverridden();

  // Note that we only check if a File was returned. If it was out-of-date
  // we have complained but we will continue creating a FileID to recover
  // gracefully.
  if (!File)
    return true;

  SourceLocation IncludeLoc = ReadSourceLocation(*F, Record[1]);
  if (IncludeLoc.isInvalid() && F->Kind != MK_MainFile) {
    // This is the module's main file.
    IncludeLoc = getImportLocation(F);
  }
  SrcMgr::CharacteristicKind
    FileCharacter = (SrcMgr::CharacteristicKind)Record[2];
  FileID FID = SourceMgr.createFileID(*File, IncludeLoc, FileCharacter, ID,
                                      BaseOffset + Record[0]);
  SrcMgr::FileInfo &FileInfo =
        const_cast<SrcMgr::FileInfo&>(SourceMgr.getSLocEntry(FID).getFile());
  FileInfo.NumCreatedFIDs = Record[5];
  if (Record[3])
    FileInfo.setHasLineDirectives();

  unsigned NumFileDecls = Record[7];
  if (NumFileDecls && ContextObj) {
    const DeclID *FirstDecl = F->FileSortedDecls + Record[6];
    assert(F->FileSortedDecls && "FILE_SORTED_DECLS not encountered yet ?")((void)0);
    FileDeclIDs[FID] = FileDeclsInfo(F, llvm::makeArrayRef(FirstDecl,
                                                           NumFileDecls));
  }

  const SrcMgr::ContentCache &ContentCache =
      SourceMgr.getOrCreateContentCache(*File, isSystem(FileCharacter));
  if (OverriddenBuffer && !ContentCache.BufferOverridden &&
      ContentCache.ContentsEntry == ContentCache.OrigEntry &&
      !ContentCache.getBufferIfLoaded()) {
    auto Buffer = ReadBuffer(SLocEntryCursor, File->getName());
    if (!Buffer)
      return true;
    SourceMgr.overrideFileContents(*File, std::move(Buffer));
  }

  break;
}

case SM_SLOC_BUFFER_ENTRY: {
  const char *Name = Blob.data();
  unsigned Offset = Record[0];
  SrcMgr::CharacteristicKind
    FileCharacter = (SrcMgr::CharacteristicKind)Record[2];
  SourceLocation IncludeLoc = ReadSourceLocation(*F, Record[1]);
  if (IncludeLoc.isInvalid() && F->isModule()) {
    IncludeLoc = getImportLocation(F);
  }

  auto Buffer = ReadBuffer(SLocEntryCursor, Name);
  if (!Buffer)
    return true;
  SourceMgr.createFileID(std::move(Buffer), FileCharacter, ID,
                         BaseOffset + Offset, IncludeLoc);
  break;
}

case SM_SLOC_EXPANSION_ENTRY: {
  SourceLocation SpellingLoc = ReadSourceLocation(*F, Record[1]);
  SourceMgr.createExpansionLoc(SpellingLoc,
                                   ReadSourceLocation(*F, Record[2]),
                                   ReadSourceLocation(*F, Record[3]),
                                   Record[5],
                                   Record[4],
                                   ID,
                                   BaseOffset + Record[0]);
  break;
}
}

return false;
1596}

1598std::pair<SourceLocation, StringRef> ASTReader::getModuleImportLoc(int ID) {
if (ID == 0)
  return std::make_pair(SourceLocation(), "");

if (unsigned(-ID) - 2 >= getTotalNumSLocs() || ID > 0) {
  Error("source location entry ID out-of-range for AST file");
  return std::make_pair(SourceLocation(), "");
}

// Find which module file this entry lands in.
ModuleFile *M = GlobalSLocEntryMap.find(-ID)->second;
if (!M->isModule())
  return std::make_pair(SourceLocation(), "");

// FIXME: Can we map this down to a particular submodule? That would be
// ideal.
return std::make_pair(M->ImportLoc, StringRef(M->ModuleName));
1615}

1617/// Find the location where the module F is imported.
1618SourceLocation ASTReader::getImportLocation(ModuleFile *F) {
if (F->ImportLoc.isValid())
  return F->ImportLoc;

// Otherwise we have a PCH. It's considered to be "imported" at the first
// location of its includer.
if (F->ImportedBy.empty() || !F->ImportedBy[0]) {
  // Main file is the importer.
  assert(SourceMgr.getMainFileID().isValid() && "missing main file")((void)0);
  return SourceMgr.getLocForStartOfFile(SourceMgr.getMainFileID());
}
return F->ImportedBy[0]->FirstLoc;
1630}

1632/// Enter a subblock of the specified BlockID with the specified cursor. Read
1633/// the abbreviations that are at the top of the block and then leave the cursor
1634/// pointing into the block.
1635bool ASTReader::ReadBlockAbbrevs(BitstreamCursor &Cursor, unsigned BlockID,
                               uint64_t *StartOfBlockOffset) {
if (llvm::Error Err = Cursor.EnterSubBlock(BlockID)) {
  // FIXME this drops errors on the floor.
  consumeError(std::move(Err));
  return true;
}

if (StartOfBlockOffset)
  *StartOfBlockOffset = Cursor.GetCurrentBitNo();

while (true) {
  uint64_t Offset = Cursor.GetCurrentBitNo();
  Expected<unsigned> MaybeCode = Cursor.ReadCode();
  if (!MaybeCode) {
    // FIXME this drops errors on the floor.
    consumeError(MaybeCode.takeError());
    return true;
  }
  unsigned Code = MaybeCode.get();

  // We expect all abbrevs to be at the start of the block.
  if (Code != llvm::bitc::DEFINE_ABBREV) {
    if (llvm::Error Err = Cursor.JumpToBit(Offset)) {
      // FIXME this drops errors on the floor.
      consumeError(std::move(Err));
      return true;
    }
    return false;
  }
  if (llvm::Error Err = Cursor.ReadAbbrevRecord()) {
    // FIXME this drops errors on the floor.
    consumeError(std::move(Err));
    return true;
  }
}
1671}

1673Token ASTReader::ReadToken(ModuleFile &F, const RecordDataImpl &Record,
                         unsigned &Idx) {
Token Tok;
Tok.startToken();
Tok.setLocation(ReadSourceLocation(F, Record, Idx));
Tok.setLength(Record[Idx++]);
if (IdentifierInfo *II = getLocalIdentifier(F, Record[Idx++]))
  Tok.setIdentifierInfo(II);
Tok.setKind((tok::TokenKind)Record[Idx++]);
Tok.setFlag((Token::TokenFlags)Record[Idx++]);
return Tok;
1684}

1686MacroInfo *ASTReader::ReadMacroRecord(ModuleFile &F, uint64_t Offset) {
BitstreamCursor &Stream = F.MacroCursor;

// Keep track of where we are in the stream, then jump back there
// after reading this macro.
SavedStreamPosition SavedPosition(Stream);

if (llvm::Error Err = Stream.JumpToBit(Offset)) {
  // FIXME this drops errors on the floor.
  consumeError(std::move(Err));
  return nullptr;
}
RecordData Record;
SmallVector<IdentifierInfo*, 16> MacroParams;
MacroInfo *Macro = nullptr;

while (true) {
  // Advance to the next record, but if we get to the end of the block, don't
  // pop it (removing all the abbreviations from the cursor) since we want to
  // be able to reseek within the block and read entries.
  unsigned Flags = BitstreamCursor::AF_DontPopBlockAtEnd;
  Expected<llvm::BitstreamEntry> MaybeEntry =
      Stream.advanceSkippingSubblocks(Flags);
  if (!MaybeEntry) {
    Error(MaybeEntry.takeError());
    return Macro;
  }
  llvm::BitstreamEntry Entry = MaybeEntry.get();

  switch (Entry.Kind) {
  case llvm::BitstreamEntry::SubBlock: // Handled for us already.
  case llvm::BitstreamEntry::Error:
    Error("malformed block record in AST file");
    return Macro;
  case llvm::BitstreamEntry::EndBlock:
    return Macro;
  case llvm::BitstreamEntry::Record:
    // The interesting case.
    break;
  }

  // Read a record.
  Record.clear();
  PreprocessorRecordTypes RecType;
  if (Expected<unsigned> MaybeRecType = Stream.readRecord(Entry.ID, Record))
    RecType = (PreprocessorRecordTypes)MaybeRecType.get();
  else {
    Error(MaybeRecType.takeError());
    return Macro;
  }
  switch (RecType) {
  case PP_MODULE_MACRO:
  case PP_MACRO_DIRECTIVE_HISTORY:
    return Macro;

  case PP_MACRO_OBJECT_LIKE:
  case PP_MACRO_FUNCTION_LIKE: {
    // If we already have a macro, that means that we've hit the end
    // of the definition of the macro we were looking for. We're
    // done.
    if (Macro)
      return Macro;

    unsigned NextIndex = 1; // Skip identifier ID.
    SourceLocation Loc = ReadSourceLocation(F, Record, NextIndex);
    MacroInfo *MI = PP.AllocateMacroInfo(Loc);
    MI->setDefinitionEndLoc(ReadSourceLocation(F, Record, NextIndex));
    MI->setIsUsed(Record[NextIndex++]);
    MI->setUsedForHeaderGuard(Record[NextIndex++]);

    if (RecType == PP_MACRO_FUNCTION_LIKE) {
      // Decode function-like macro info.
      bool isC99VarArgs = Record[NextIndex++];
      bool isGNUVarArgs = Record[NextIndex++];
      bool hasCommaPasting = Record[NextIndex++];
      MacroParams.clear();
      unsigned NumArgs = Record[NextIndex++];
      for (unsigned i = 0; i != NumArgs; ++i)
        MacroParams.push_back(getLocalIdentifier(F, Record[NextIndex++]));

      // Install function-like macro info.
      MI->setIsFunctionLike();
      if (isC99VarArgs) MI->setIsC99Varargs();
      if (isGNUVarArgs) MI->setIsGNUVarargs();
      if (hasCommaPasting) MI->setHasCommaPasting();
      MI->setParameterList(MacroParams, PP.getPreprocessorAllocator());
    }

    // Remember that we saw this macro last so that we add the tokens that
    // form its body to it.
    Macro = MI;

    if (NextIndex + 1 == Record.size() && PP.getPreprocessingRecord() &&
        Record[NextIndex]) {
      // We have a macro definition. Register the association
      PreprocessedEntityID
          GlobalID = getGlobalPreprocessedEntityID(F, Record[NextIndex]);
      PreprocessingRecord &PPRec = *PP.getPreprocessingRecord();
      PreprocessingRecord::PPEntityID PPID =
          PPRec.getPPEntityID(GlobalID - 1, /*isLoaded=*/true);
      MacroDefinitionRecord *PPDef = cast_or_null<MacroDefinitionRecord>(
          PPRec.getPreprocessedEntity(PPID));
      if (PPDef)
        PPRec.RegisterMacroDefinition(Macro, PPDef);
    }

    ++NumMacrosRead;
    break;
  }

  case PP_TOKEN: {
    // If we see a TOKEN before a PP_MACRO_*, then the file is
    // erroneous, just pretend we didn't see this.
    if (!Macro) break;

    unsigned Idx = 0;
    Token Tok = ReadToken(F, Record, Idx);
    Macro->AddTokenToBody(Tok);
    break;
  }
  }
}
1808}

1810PreprocessedEntityID
1811ASTReader::getGlobalPreprocessedEntityID(ModuleFile &M,
                                       unsigned LocalID) const {
if (!M.ModuleOffsetMap.empty())
  ReadModuleOffsetMap(M);

ContinuousRangeMap<uint32_t, int, 2>::const_iterator
  I = M.PreprocessedEntityRemap.find(LocalID - NUM_PREDEF_PP_ENTITY_IDS);
assert(I != M.PreprocessedEntityRemap.end()((void)0)
       && "Invalid index into preprocessed entity index remap")((void)0);

return LocalID + I->second;
1822}

1824unsigned HeaderFileInfoTrait::ComputeHash(internal_key_ref ikey) {
return llvm::hash_combine(ikey.Size, ikey.ModTime);
1826}

1828HeaderFileInfoTrait::internal_key_type
1829HeaderFileInfoTrait::GetInternalKey(const FileEntry *FE) {
internal_key_type ikey = {FE->getSize(),
                          M.HasTimestamps ? FE->getModificationTime() : 0,
                          FE->getName(), /*Imported*/ false};
return ikey;
1834}

1836bool HeaderFileInfoTrait::EqualKey(internal_key_ref a, internal_key_ref b) {
if (a.Size != b.Size || (a.ModTime && b.ModTime && a.ModTime != b.ModTime))
  return false;

if (llvm::sys::path::is_absolute(a.Filename) && a.Filename == b.Filename)
  return true;

// Determine whether the actual files are equivalent.
FileManager &FileMgr = Reader.getFileManager();
auto GetFile = [&](const internal_key_type &Key) -> const FileEntry* {
  if (!Key.Imported) {
    if (auto File = FileMgr.getFile(Key.Filename))
      return *File;
    return nullptr;
  }

  std::string Resolved = std::string(Key.Filename);
  Reader.ResolveImportedPath(M, Resolved);
  if (auto File = FileMgr.getFile(Resolved))
    return *File;
  return nullptr;
};

const FileEntry *FEA = GetFile(a);
const FileEntry *FEB = GetFile(b);
return FEA && FEA == FEB;
1862}

1864std::pair<unsigned, unsigned>
1865HeaderFileInfoTrait::ReadKeyDataLength(const unsigned char*& d) {
return readULEBKeyDataLength(d);
1867}

1869HeaderFileInfoTrait::internal_key_type
1870HeaderFileInfoTrait::ReadKey(const unsigned char *d, unsigned) {
using namespace llvm::support;

internal_key_type ikey;
ikey.Size = off_t(endian::readNext<uint64_t, little, unaligned>(d));
ikey.ModTime = time_t(endian::readNext<uint64_t, little, unaligned>(d));
ikey.Filename = (const char *)d;
ikey.Imported = true;
return ikey;
1879}

1881HeaderFileInfoTrait::data_type
1882HeaderFileInfoTrait::ReadData(internal_key_ref key, const unsigned char *d,
                            unsigned DataLen) {
using namespace llvm::support;

const unsigned char *End = d + DataLen;
HeaderFileInfo HFI;
unsigned Flags = *d++;
// FIXME: Refactor with mergeHeaderFileInfo in HeaderSearch.cpp.
HFI.isImport |= (Flags >> 5) & 0x01;
HFI.isPragmaOnce |= (Flags >> 4) & 0x01;
HFI.DirInfo = (Flags >> 1) & 0x07;
HFI.IndexHeaderMapHeader = Flags & 0x01;
// FIXME: Find a better way to handle this. Maybe just store a
// "has been included" flag?
HFI.NumIncludes = std::max(endian::readNext<uint16_t, little, unaligned>(d),
                           HFI.NumIncludes);
HFI.ControllingMacroID = Reader.getGlobalIdentifierID(
    M, endian::readNext<uint32_t, little, unaligned>(d));
if (unsigned FrameworkOffset =
        endian::readNext<uint32_t, little, unaligned>(d)) {
  // The framework offset is 1 greater than the actual offset,
  // since 0 is used as an indicator for "no framework name".
  StringRef FrameworkName(FrameworkStrings + FrameworkOffset - 1);
  HFI.Framework = HS->getUniqueFrameworkName(FrameworkName);
}

assert((End - d) % 4 == 0 &&((void)0)
       "Wrong data length in HeaderFileInfo deserialization")((void)0);
while (d != End) {
  uint32_t LocalSMID = endian::readNext<uint32_t, little, unaligned>(d);
  auto HeaderRole = static_cast<ModuleMap::ModuleHeaderRole>(LocalSMID & 3);
  LocalSMID >>= 2;

  // This header is part of a module. Associate it with the module to enable
  // implicit module import.
  SubmoduleID GlobalSMID = Reader.getGlobalSubmoduleID(M, LocalSMID);
  Module *Mod = Reader.getSubmodule(GlobalSMID);
  FileManager &FileMgr = Reader.getFileManager();
  ModuleMap &ModMap =
      Reader.getPreprocessor().getHeaderSearchInfo().getModuleMap();

  std::string Filename = std::string(key.Filename);
  if (key.Imported)
    Reader.ResolveImportedPath(M, Filename);
  // FIXME: NameAsWritten
  Module::Header H = {std::string(key.Filename), "",
                      *FileMgr.getFile(Filename)};
  ModMap.addHeader(Mod, H, HeaderRole, /*Imported*/true);
  HFI.isModuleHeader |= !(HeaderRole & ModuleMap::TextualHeader);
}

// This HeaderFileInfo was externally loaded.
HFI.External = true;
HFI.IsValid = true;
return HFI;
1937}

1939void ASTReader::addPendingMacro(IdentifierInfo *II, ModuleFile *M,
                              uint32_t MacroDirectivesOffset) {
assert(NumCurrentElementsDeserializing > 0 &&"Missing deserialization guard")((void)0);
PendingMacroIDs[II].push_back(PendingMacroInfo(M, MacroDirectivesOffset));
1943}

1945void ASTReader::ReadDefinedMacros() {
// Note that we are loading defined macros.
Deserializing Macros(this);

for (ModuleFile &I : llvm::reverse(ModuleMgr)) {
  BitstreamCursor &MacroCursor = I.MacroCursor;

  // If there was no preprocessor block, skip this file.
  if (MacroCursor.getBitcodeBytes().empty())
    continue;

  BitstreamCursor Cursor = MacroCursor;
  if (llvm::Error Err = Cursor.JumpToBit(I.MacroStartOffset)) {
    Error(std::move(Err));
    return;
  }

  RecordData Record;
  while (true) {
    Expected<llvm::BitstreamEntry> MaybeE = Cursor.advanceSkippingSubblocks();
    if (!MaybeE) {
      Error(MaybeE.takeError());
      return;
    }
    llvm::BitstreamEntry E = MaybeE.get();

    switch (E.Kind) {
    case llvm::BitstreamEntry::SubBlock: // Handled for us already.
    case llvm::BitstreamEntry::Error:
      Error("malformed block record in AST file");
      return;
    case llvm::BitstreamEntry::EndBlock:
      goto NextCursor;

    case llvm::BitstreamEntry::Record: {
      Record.clear();
      Expected<unsigned> MaybeRecord = Cursor.readRecord(E.ID, Record);
      if (!MaybeRecord) {
        Error(MaybeRecord.takeError());
        return;
      }
      switch (MaybeRecord.get()) {
      default:  // Default behavior: ignore.
        break;

      case PP_MACRO_OBJECT_LIKE:
      case PP_MACRO_FUNCTION_LIKE: {
        IdentifierInfo *II = getLocalIdentifier(I, Record[0]);
        if (II->isOutOfDate())
          updateOutOfDateIdentifier(*II);
        break;
      }

      case PP_TOKEN:
        // Ignore tokens.
        break;
      }
      break;
    }
    }
  }
  NextCursor:  ;
}
2008}

2010namespace {

/// Visitor class used to look up identifirs in an AST file.
class IdentifierLookupVisitor {
  StringRef Name;
  unsigned NameHash;
  unsigned PriorGeneration;
  unsigned &NumIdentifierLookups;
  unsigned &NumIdentifierLookupHits;
  IdentifierInfo *Found = nullptr;

public:
  IdentifierLookupVisitor(StringRef Name, unsigned PriorGeneration,
                          unsigned &NumIdentifierLookups,
                          unsigned &NumIdentifierLookupHits)
    : Name(Name), NameHash(ASTIdentifierLookupTrait::ComputeHash(Name)),
      PriorGeneration(PriorGeneration),
      NumIdentifierLookups(NumIdentifierLookups),
      NumIdentifierLookupHits(NumIdentifierLookupHits) {}

  bool operator()(ModuleFile &M) {
    // If we've already searched this module file, skip it now.
    if (M.Generation <= PriorGeneration)
      return true;

    ASTIdentifierLookupTable *IdTable
      = (ASTIdentifierLookupTable *)M.IdentifierLookupTable;
    if (!IdTable)
      return false;

    ASTIdentifierLookupTrait Trait(IdTable->getInfoObj().getReader(), M,
                                   Found);
    ++NumIdentifierLookups;
    ASTIdentifierLookupTable::iterator Pos =
        IdTable->find_hashed(Name, NameHash, &Trait);
    if (Pos == IdTable->end())
      return false;

    // Dereferencing the iterator has the effect of building the
    // IdentifierInfo node and populating it with the various
    // declarations it needs.
    ++NumIdentifierLookupHits;
    Found = *Pos;
    return true;
  }

  // Retrieve the identifier info found within the module
  // files.
  IdentifierInfo *getIdentifierInfo() const { return Found; }
};

2061} // namespace

2063void ASTReader::updateOutOfDateIdentifier(IdentifierInfo &II) {
// Note that we are loading an identifier.
Deserializing AnIdentifier(this);

unsigned PriorGeneration = 0;
if (getContext().getLangOpts().Modules)
  PriorGeneration = IdentifierGeneration[&II];

// If there is a global index, look there first to determine which modules
// provably do not have any results for this identifier.
GlobalModuleIndex::HitSet Hits;
GlobalModuleIndex::HitSet *HitsPtr = nullptr;
if (!loadGlobalIndex()) {
  if (GlobalIndex->lookupIdentifier(II.getName(), Hits)) {
    HitsPtr = &Hits;
  }
}

IdentifierLookupVisitor Visitor(II.getName(), PriorGeneration,
                                NumIdentifierLookups,
                                NumIdentifierLookupHits);
ModuleMgr.visit(Visitor, HitsPtr);
markIdentifierUpToDate(&II);
2086}

2088void ASTReader::markIdentifierUpToDate(IdentifierInfo *II) {
if (!II)
  return;

II->setOutOfDate(false);

// Update the generation for this identifier.
if (getContext().getLangOpts().Modules)
  IdentifierGeneration[II] = getGeneration();
2097}

2099void ASTReader::resolvePendingMacro(IdentifierInfo *II,
                                  const PendingMacroInfo &PMInfo) {
ModuleFile &M = *PMInfo.M;

BitstreamCursor &Cursor = M.MacroCursor;
SavedStreamPosition SavedPosition(Cursor);
if (llvm::Error Err =
        Cursor.JumpToBit(M.MacroOffsetsBase + PMInfo.MacroDirectivesOffset)) {
  Error(std::move(Err));
  return;
}

struct ModuleMacroRecord {
  SubmoduleID SubModID;
  MacroInfo *MI;
  SmallVector<SubmoduleID, 8> Overrides;
};
llvm::SmallVector<ModuleMacroRecord, 8> ModuleMacros;

// We expect to see a sequence of PP_MODULE_MACRO records listing exported
// macros, followed by a PP_MACRO_DIRECTIVE_HISTORY record with the complete
// macro histroy.
RecordData Record;
while (true) {
  Expected<llvm::BitstreamEntry> MaybeEntry =
      Cursor.advance(BitstreamCursor::AF_DontPopBlockAtEnd);
  if (!MaybeEntry) {
    Error(MaybeEntry.takeError());
    return;
  }
  llvm::BitstreamEntry Entry = MaybeEntry.get();

  if (Entry.Kind != llvm::BitstreamEntry::Record) {
    Error("malformed block record in AST file");
    return;
  }

  Record.clear();
  Expected<unsigned> MaybePP = Cursor.readRecord(Entry.ID, Record);
  if (!MaybePP) {
    Error(MaybePP.takeError());
    return;
  }
  switch ((PreprocessorRecordTypes)MaybePP.get()) {
  case PP_MACRO_DIRECTIVE_HISTORY:
    break;

  case PP_MODULE_MACRO: {
    ModuleMacros.push_back(ModuleMacroRecord());
    auto &Info = ModuleMacros.back();
    Info.SubModID = getGlobalSubmoduleID(M, Record[0]);
    Info.MI = getMacro(getGlobalMacroID(M, Record[1]));
    for (int I = 2, N = Record.size(); I != N; ++I)
      Info.Overrides.push_back(getGlobalSubmoduleID(M, Record[I]));
    continue;
  }

  default:
    Error("malformed block record in AST file");
    return;
  }

  // We found the macro directive history; that's the last record
  // for this macro.
  break;
}

// Module macros are listed in reverse dependency order.
{
  std::reverse(ModuleMacros.begin(), ModuleMacros.end());
  llvm::SmallVector<ModuleMacro*, 8> Overrides;
  for (auto &MMR : ModuleMacros) {
    Overrides.clear();
    for (unsigned ModID : MMR.Overrides) {
      Module *Mod = getSubmodule(ModID);
      auto *Macro = PP.getModuleMacro(Mod, II);
      assert(Macro && "missing definition for overridden macro")((void)0);
      Overrides.push_back(Macro);
    }

    bool Inserted = false;
    Module *Owner = getSubmodule(MMR.SubModID);
    PP.addModuleMacro(Owner, II, MMR.MI, Overrides, Inserted);
  }
}

// Don't read the directive history for a module; we don't have anywhere
// to put it.
if (M.isModule())
  return;

// Deserialize the macro directives history in reverse source-order.
MacroDirective *Latest = nullptr, *Earliest = nullptr;
unsigned Idx = 0, N = Record.size();
while (Idx < N) {
  MacroDirective *MD = nullptr;
  SourceLocation Loc = ReadSourceLocation(M, Record, Idx);
  MacroDirective::Kind K = (MacroDirective::Kind)Record[Idx++];
  switch (K) {
  case MacroDirective::MD_Define: {
    MacroInfo *MI = getMacro(getGlobalMacroID(M, Record[Idx++]));
    MD = PP.AllocateDefMacroDirective(MI, Loc);
    break;
  }
  case MacroDirective::MD_Undefine:
    MD = PP.AllocateUndefMacroDirective(Loc);
    break;
  case MacroDirective::MD_Visibility:
    bool isPublic = Record[Idx++];
    MD = PP.AllocateVisibilityMacroDirective(Loc, isPublic);
    break;
  }

  if (!Latest)
    Latest = MD;
  if (Earliest)
    Earliest->setPrevious(MD);
  Earliest = MD;
}

if (Latest)
  PP.setLoadedMacroDirective(II, Earliest, Latest);
2221}

2223bool ASTReader::shouldDisableValidationForFile(
  const serialization::ModuleFile &M) const {
if (DisableValidationKind == DisableValidationForModuleKind::None)
  return false;

// If a PCH is loaded and validation is disabled for PCH then disable
// validation for the PCH and the modules it loads.
ModuleKind K = CurrentDeserializingModuleKind.getValueOr(M.Kind);

switch (K) {
case MK_MainFile:
case MK_Preamble:
case MK_PCH:
  return bool(DisableValidationKind & DisableValidationForModuleKind::PCH);
case MK_ImplicitModule:
case MK_ExplicitModule:
case MK_PrebuiltModule:
  return bool(DisableValidationKind & DisableValidationForModuleKind::Module);
}

return false;
2244}

2246ASTReader::InputFileInfo
2247ASTReader::readInputFileInfo(ModuleFile &F, unsigned ID) {
// Go find this input file.
BitstreamCursor &Cursor = F.InputFilesCursor;
SavedStreamPosition SavedPosition(Cursor);
if (llvm::Error Err = Cursor.JumpToBit(F.InputFileOffsets[ID - 1])) {
  // FIXME this drops errors on the floor.
  consumeError(std::move(Err));
}

Expected<unsigned> MaybeCode = Cursor.ReadCode();
if (!MaybeCode) {
  // FIXME this drops errors on the floor.
  consumeError(MaybeCode.takeError());
}
unsigned Code = MaybeCode.get();
RecordData Record;
StringRef Blob;

if (Expected<unsigned> Maybe = Cursor.readRecord(Code, Record, &Blob))
  assert(static_cast<InputFileRecordTypes>(Maybe.get()) == INPUT_FILE &&((void)0)
         "invalid record type for input file")((void)0);
else {
  // FIXME this drops errors on the floor.
  consumeError(Maybe.takeError());
}

assert(Record[0] == ID && "Bogus stored ID or offset")((void)0);
InputFileInfo R;
R.StoredSize = static_cast<off_t>(Record[1]);
R.StoredTime = static_cast<time_t>(Record[2]);
R.Overridden = static_cast<bool>(Record[3]);
R.Transient = static_cast<bool>(Record[4]);
R.TopLevelModuleMap = static_cast<bool>(Record[5]);
R.Filename = std::string(Blob);
ResolveImportedPath(F, R.Filename);

Expected<llvm::BitstreamEntry> MaybeEntry = Cursor.advance();
if (!MaybeEntry) // FIXME this drops errors on the floor.
  consumeError(MaybeEntry.takeError());
llvm::BitstreamEntry Entry = MaybeEntry.get();
assert(Entry.Kind == llvm::BitstreamEntry::Record &&((void)0)
       "expected record type for input file hash")((void)0);

Record.clear();
if (Expected<unsigned> Maybe = Cursor.readRecord(Entry.ID, Record))
  assert(static_cast<InputFileRecordTypes>(Maybe.get()) == INPUT_FILE_HASH &&((void)0)
         "invalid record type for input file hash")((void)0);
else {
  // FIXME this drops errors on the floor.
  consumeError(Maybe.takeError());
}
R.ContentHash = (static_cast<uint64_t>(Record[1]) << 32) |
                static_cast<uint64_t>(Record[0]);
return R;
2301}

2303static unsigned moduleKindForDiagnostic(ModuleKind Kind);
2304InputFile ASTReader::getInputFile(ModuleFile &F, unsigned ID, bool Complain) {
// If this ID is bogus, just return an empty input file.
if (ID == 0 || ID > F.InputFilesLoaded.size())
  return InputFile();

// If we've already loaded this input file, return it.
if (F.InputFilesLoaded[ID-1].getFile())
  return F.InputFilesLoaded[ID-1];

if (F.InputFilesLoaded[ID-1].isNotFound())
  return InputFile();

// Go find this input file.
BitstreamCursor &Cursor = F.InputFilesCursor;
SavedStreamPosition SavedPosition(Cursor);
if (llvm::Error Err = Cursor.JumpToBit(F.InputFileOffsets[ID - 1])) {
  // FIXME this drops errors on the floor.
  consumeError(std::move(Err));
}

InputFileInfo FI = readInputFileInfo(F, ID);
off_t StoredSize = FI.StoredSize;
time_t StoredTime = FI.StoredTime;
bool Overridden = FI.Overridden;
bool Transient = FI.Transient;
StringRef Filename = FI.Filename;
uint64_t StoredContentHash = FI.ContentHash;

OptionalFileEntryRefDegradesToFileEntryPtr File =
    expectedToOptional(FileMgr.getFileRef(Filename, /*OpenFile=*/false));

// If we didn't find the file, resolve it relative to the
// original directory from which this AST file was created.
if (!File && !F.OriginalDir.empty() && !F.BaseDirectory.empty() &&
    F.OriginalDir != F.BaseDirectory) {
  std::string Resolved = resolveFileRelativeToOriginalDir(
      std::string(Filename), F.OriginalDir, F.BaseDirectory);
  if (!Resolved.empty())
    File = expectedToOptional(FileMgr.getFileRef(Resolved));
}

// For an overridden file, create a virtual file with the stored
// size/timestamp.
if ((Overridden || Transient) && !File)
  File = FileMgr.getVirtualFileRef(Filename, StoredSize, StoredTime);

if (!File) {
  if (Complain) {
    std::string ErrorStr = "could not find file '";
    ErrorStr += Filename;
    ErrorStr += "' referenced by AST file '";
    ErrorStr += F.FileName;
    ErrorStr += "'";
    Error(ErrorStr);
  }
  // Record that we didn't find the file.
  F.InputFilesLoaded[ID-1] = InputFile::getNotFound();
  return InputFile();
}

// Check if there was a request to override the contents of the file
// that was part of the precompiled header. Overriding such a file
// can lead to problems when lexing using the source locations from the
// PCH.
SourceManager &SM = getSourceManager();
// FIXME: Reject if the overrides are different.
if ((!Overridden && !Transient) && SM.isFileOverridden(File)) {
  if (Complain)
    Error(diag::err_fe_pch_file_overridden, Filename);

  // After emitting the diagnostic, bypass the overriding file to recover
  // (this creates a separate FileEntry).
  File = SM.bypassFileContentsOverride(*File);
  if (!File) {
    F.InputFilesLoaded[ID - 1] = InputFile::getNotFound();
    return InputFile();
  }
}

enum ModificationType {
  Size,
  ModTime,
  Content,
  None,
};
auto HasInputFileChanged = [&]() {
  if (StoredSize != File->getSize())
    return ModificationType::Size;
  if (!shouldDisableValidationForFile(F) && StoredTime &&
      StoredTime != File->getModificationTime()) {
    // In case the modification time changes but not the content,
    // accept the cached file as legit.
    if (ValidateASTInputFilesContent &&
        StoredContentHash != static_cast<uint64_t>(llvm::hash_code(-1))) {
      auto MemBuffOrError = FileMgr.getBufferForFile(File);
      if (!MemBuffOrError) {
        if (!Complain)
          return ModificationType::ModTime;
        std::string ErrorStr = "could not get buffer for file '";
        ErrorStr += File->getName();
        ErrorStr += "'";
        Error(ErrorStr);
        return ModificationType::ModTime;
      }

      auto ContentHash = hash_value(MemBuffOrError.get()->getBuffer());
      if (StoredContentHash == static_cast<uint64_t>(ContentHash))
        return ModificationType::None;
      return ModificationType::Content;
    }
    return ModificationType::ModTime;
  }
  return ModificationType::None;
};

bool IsOutOfDate = false;
auto FileChange = HasInputFileChanged();
// For an overridden file, there is nothing to validate.
if (!Overridden && FileChange != ModificationType::None) {
  if (Complain && !Diags.isDiagnosticInFlight()) {
    // Build a list of the PCH imports that got us here (in reverse).
    SmallVector<ModuleFile *, 4> ImportStack(1, &F);
    while (!ImportStack.back()->ImportedBy.empty())
      ImportStack.push_back(ImportStack.back()->ImportedBy[0]);

    // The top-level PCH is stale.
    StringRef TopLevelPCHName(ImportStack.back()->FileName);
    Diag(diag::err_fe_ast_file_modified)
        << Filename << moduleKindForDiagnostic(ImportStack.back()->Kind)
        << TopLevelPCHName << FileChange;

    // Print the import stack.
    if (ImportStack.size() > 1) {
      Diag(diag::note_pch_required_by)
        << Filename << ImportStack[0]->FileName;
      for (unsigned I = 1; I < ImportStack.size(); ++I)
        Diag(diag::note_pch_required_by)
          << ImportStack[I-1]->FileName << ImportStack[I]->FileName;
    }

    Diag(diag::note_pch_rebuild_required) << TopLevelPCHName;
  }

  IsOutOfDate = true;
}
// FIXME: If the file is overridden and we've already opened it,
// issue an error (or split it into a separate FileEntry).

InputFile IF = InputFile(*File, Overridden || Transient, IsOutOfDate);

// Note that we've loaded this input file.
F.InputFilesLoaded[ID-1] = IF;
return IF;
2457}

2459/// If we are loading a relocatable PCH or module file, and the filename
2460/// is not an absolute path, add the system or module root to the beginning of
2461/// the file name.
2462void ASTReader::ResolveImportedPath(ModuleFile &M, std::string &Filename) {
// Resolve relative to the base directory, if we have one.
if (!M.BaseDirectory.empty())
  return ResolveImportedPath(Filename, M.BaseDirectory);
2466}

2468void ASTReader::ResolveImportedPath(std::string &Filename, StringRef Prefix) {
if (Filename.empty() || llvm::sys::path::is_absolute(Filename))
  return;

SmallString<128> Buffer;
llvm::sys::path::append(Buffer, Prefix, Filename);
Filename.assign(Buffer.begin(), Buffer.end());
2475}

2477static bool isDiagnosedResult(ASTReader::ASTReadResult ARR, unsigned Caps) {
switch (ARR) {
case ASTReader::Failure: return true;
case ASTReader::Missing: return !(Caps & ASTReader::ARR_Missing);
case ASTReader::OutOfDate: return !(Caps & ASTReader::ARR_OutOfDate);
case ASTReader::VersionMismatch: return !(Caps & ASTReader::ARR_VersionMismatch);
case ASTReader::ConfigurationMismatch:
  return !(Caps & ASTReader::ARR_ConfigurationMismatch);
case ASTReader::HadErrors: return true;
case ASTReader::Success: return false;
}

llvm_unreachable("unknown ASTReadResult")__builtin_unreachable();
2490}

2492ASTReader::ASTReadResult ASTReader::ReadOptionsBlock(
  BitstreamCursor &Stream, unsigned ClientLoadCapabilities,
  bool AllowCompatibleConfigurationMismatch, ASTReaderListener &Listener,
  std::string &SuggestedPredefines) {
if (llvm::Error Err = Stream.EnterSubBlock(OPTIONS_BLOCK_ID)) {
  // FIXME this drops errors on the floor.
  consumeError(std::move(Err));
  return Failure;
}

// Read all of the records in the options block.
RecordData Record;
ASTReadResult Result = Success;
while (true) {
  Expected<llvm::BitstreamEntry> MaybeEntry = Stream.advance();
  if (!MaybeEntry) {
    // FIXME this drops errors on the floor.
    consumeError(MaybeEntry.takeError());
    return Failure;
  }
  llvm::BitstreamEntry Entry = MaybeEntry.get();

  switch (Entry.Kind) {
  case llvm::BitstreamEntry::Error:
  case llvm::BitstreamEntry::SubBlock:
    return Failure;

  case llvm::BitstreamEntry::EndBlock:
    return Result;

  case llvm::BitstreamEntry::Record:
    // The interesting case.
    break;
  }

  // Read and process a record.
  Record.clear();
  Expected<unsigned> MaybeRecordType = Stream.readRecord(Entry.ID, Record);
  if (!MaybeRecordType) {
    // FIXME this drops errors on the floor.
    consumeError(MaybeRecordType.takeError());
    return Failure;
  }
  switch ((OptionsRecordTypes)MaybeRecordType.get()) {
  case LANGUAGE_OPTIONS: {
    bool Complain = (ClientLoadCapabilities & ARR_ConfigurationMismatch) == 0;
    if (ParseLanguageOptions(Record, Complain, Listener,
                             AllowCompatibleConfigurationMismatch))
      Result = ConfigurationMismatch;
    break;
  }

  case TARGET_OPTIONS: {
    bool Complain = (ClientLoadCapabilities & ARR_ConfigurationMismatch) == 0;
    if (ParseTargetOptions(Record, Complain, Listener,
                           AllowCompatibleConfigurationMismatch))
      Result = ConfigurationMismatch;
    break;
  }

  case FILE_SYSTEM_OPTIONS: {
    bool Complain = (ClientLoadCapabilities & ARR_ConfigurationMismatch) == 0;
    if (!AllowCompatibleConfigurationMismatch &&
        ParseFileSystemOptions(Record, Complain, Listener))
      Result = ConfigurationMismatch;
    break;
  }

  case HEADER_SEARCH_OPTIONS: {
    bool Complain = (ClientLoadCapabilities & ARR_ConfigurationMismatch) == 0;
    if (!AllowCompatibleConfigurationMismatch &&
        ParseHeaderSearchOptions(Record, Complain, Listener))
      Result = ConfigurationMismatch;
    break;
  }

  case PREPROCESSOR_OPTIONS:
    bool Complain = (ClientLoadCapabilities & ARR_ConfigurationMismatch) == 0;
    if (!AllowCompatibleConfigurationMismatch &&
        ParsePreprocessorOptions(Record, Complain, Listener,
                                 SuggestedPredefines))
      Result = ConfigurationMismatch;
    break;
  }
}
2577}

2579ASTReader::ASTReadResult
2580ASTReader::ReadControlBlock(ModuleFile &F,
                          SmallVectorImpl<ImportedModule> &Loaded,
                          const ModuleFile *ImportedBy,
                          unsigned ClientLoadCapabilities) {
BitstreamCursor &Stream = F.Stream;

if (llvm::Error Err = Stream.EnterSubBlock(CONTROL_BLOCK_ID)) {
  Error(std::move(Err));
  return Failure;
}

// Lambda to read the unhashed control block the first time it's called.
//
// For PCM files, the unhashed control block cannot be read until after the
// MODULE_NAME record.  However, PCH files have no MODULE_NAME, and yet still
// need to look ahead before reading the IMPORTS record.  For consistency,
// this block is always read somehow (see BitstreamEntry::EndBlock).
bool HasReadUnhashedControlBlock = false;
auto readUnhashedControlBlockOnce = [&]() {
  if (!HasReadUnhashedControlBlock) {
    HasReadUnhashedControlBlock = true;
    if (ASTReadResult Result =
            readUnhashedControlBlock(F, ImportedBy, ClientLoadCapabilities))
      return Result;
  }
  return Success;
};

bool DisableValidation = shouldDisableValidationForFile(F);

// Read all of the records and blocks in the control block.
RecordData Record;
unsigned NumInputs = 0;
unsigned NumUserInputs = 0;
StringRef BaseDirectoryAsWritten;
while (true) {
  Expected<llvm::BitstreamEntry> MaybeEntry = Stream.advance();
  if (!MaybeEntry) {
    Error(MaybeEntry.takeError());
    return Failure;
  }
  llvm::BitstreamEntry Entry = MaybeEntry.get();

  switch (Entry.Kind) {
  case llvm::BitstreamEntry::Error:
    Error("malformed block record in AST file");
    return Failure;
  case llvm::BitstreamEntry::EndBlock: {
    // Validate the module before returning.  This call catches an AST with
    // no module name and no imports.
    if (ASTReadResult Result = readUnhashedControlBlockOnce())
      return Result;

    // Validate input files.
    const HeaderSearchOptions &HSOpts =
        PP.getHeaderSearchInfo().getHeaderSearchOpts();

    // All user input files reside at the index range [0, NumUserInputs), and
    // system input files reside at [NumUserInputs, NumInputs). For explicitly
    // loaded module files, ignore missing inputs.
    if (!DisableValidation && F.Kind != MK_ExplicitModule &&
        F.Kind != MK_PrebuiltModule) {
      bool Complain = (ClientLoadCapabilities & ARR_OutOfDate) == 0;

      // If we are reading a module, we will create a verification timestamp,
      // so we verify all input files.  Otherwise, verify only user input
      // files.

      unsigned N = NumUserInputs;
      if (ValidateSystemInputs ||
          (HSOpts.ModulesValidateOncePerBuildSession &&
           F.InputFilesValidationTimestamp <= HSOpts.BuildSessionTimestamp &&
           F.Kind == MK_ImplicitModule))
        N = NumInputs;

      for (unsigned I = 0; I < N; ++I) {
        InputFile IF = getInputFile(F, I+1, Complain);
        if (!IF.getFile() || IF.isOutOfDate())
          return OutOfDate;
      }
    }

    if (Listener)
      Listener->visitModuleFile(F.FileName, F.Kind);

    if (Listener && Listener->needsInputFileVisitation()) {
      unsigned N = Listener->needsSystemInputFileVisitation() ? NumInputs
                                                              : NumUserInputs;
      for (unsigned I = 0; I < N; ++I) {
        bool IsSystem = I >= NumUserInputs;
        InputFileInfo FI = readInputFileInfo(F, I+1);
        Listener->visitInputFile(FI.Filename, IsSystem, FI.Overridden,
                                 F.Kind == MK_ExplicitModule ||
                                 F.Kind == MK_PrebuiltModule);
      }
    }

    return Success;
  }

  case llvm::BitstreamEntry::SubBlock:
    switch (Entry.ID) {
    case INPUT_FILES_BLOCK_ID:
      F.InputFilesCursor = Stream;
      if (llvm::Error Err = Stream.SkipBlock()) {
        Error(std::move(Err));
        return Failure;
      }
      if (ReadBlockAbbrevs(F.InputFilesCursor, INPUT_FILES_BLOCK_ID)) {
        Error("malformed block record in AST file");
        return Failure;
      }
      continue;

    case OPTIONS_BLOCK_ID:
      // If we're reading the first module for this group, check its options
      // are compatible with ours. For modules it imports, no further checking
      // is required, because we checked them when we built it.
      if (Listener && !ImportedBy) {
        // Should we allow the configuration of the module file to differ from
        // the configuration of the current translation unit in a compatible
        // way?
        //
        // FIXME: Allow this for files explicitly specified with -include-pch.
        bool AllowCompatibleConfigurationMismatch =
            F.Kind == MK_ExplicitModule || F.Kind == MK_PrebuiltModule;

        ASTReadResult Result =
            ReadOptionsBlock(Stream, ClientLoadCapabilities,
                             AllowCompatibleConfigurationMismatch, *Listener,
                             SuggestedPredefines);
        if (Result == Failure) {
          Error("malformed block record in AST file");
          return Result;
        }

        if (DisableValidation ||
            (AllowConfigurationMismatch && Result == ConfigurationMismatch))
          Result = Success;

        // If we can't load the module, exit early since we likely
        // will rebuild the module anyway. The stream may be in the
        // middle of a block.
        if (Result != Success)
          return Result;
      } else if (llvm::Error Err = Stream.SkipBlock()) {
        Error(std::move(Err));
        return Failure;
      }
      continue;

    default:
      if (llvm::Error Err = Stream.SkipBlock()) {
        Error(std::move(Err));
        return Failure;
      }
      continue;
    }

  case llvm::BitstreamEntry::Record:
    // The interesting case.
    break;
  }

  // Read and process a record.
  Record.clear();
  StringRef Blob;
  Expected<unsigned> MaybeRecordType =
      Stream.readRecord(Entry.ID, Record, &Blob);
  if (!MaybeRecordType) {
    Error(MaybeRecordType.takeError());
    return Failure;
  }
  switch ((ControlRecordTypes)MaybeRecordType.get()) {
  case METADATA: {
    if (Record[0] != VERSION_MAJOR && !DisableValidation) {
      if ((ClientLoadCapabilities & ARR_VersionMismatch) == 0)
        Diag(Record[0] < VERSION_MAJOR? diag::err_pch_version_too_old
                                      : diag::err_pch_version_too_new);
      return VersionMismatch;
    }

    bool hasErrors = Record[6];
    if (hasErrors && !DisableValidation) {
      // If requested by the caller and the module hasn't already been read
      // or compiled, mark modules on error as out-of-date.
      if ((ClientLoadCapabilities & ARR_TreatModuleWithErrorsAsOutOfDate) &&
          canRecoverFromOutOfDate(F.FileName, ClientLoadCapabilities))
        return OutOfDate;

      if (!AllowASTWithCompilerErrors) {
        Diag(diag::err_pch_with_compiler_errors);
        return HadErrors;
      }
    }
    if (hasErrors) {
      Diags.ErrorOccurred = true;
      Diags.UncompilableErrorOccurred = true;
      Diags.UnrecoverableErrorOccurred = true;
    }

    F.RelocatablePCH = Record[4];
    // Relative paths in a relocatable PCH are relative to our sysroot.
    if (F.RelocatablePCH)
      F.BaseDirectory = isysroot.empty() ? "/" : isysroot;

    F.HasTimestamps = Record[5];

    const std::string &CurBranch = getClangFullRepositoryVersion();
    StringRef ASTBranch = Blob;
    if (StringRef(CurBranch) != ASTBranch && !DisableValidation) {
      if ((ClientLoadCapabilities & ARR_VersionMismatch) == 0)
        Diag(diag::err_pch_different_branch) << ASTBranch << CurBranch;
      return VersionMismatch;
    }
    break;
  }

  case IMPORTS: {
    // Validate the AST before processing any imports (otherwise, untangling
    // them can be error-prone and expensive).  A module will have a name and
    // will already have been validated, but this catches the PCH case.
    if (ASTReadResult Result = readUnhashedControlBlockOnce())
      return Result;

    // Load each of the imported PCH files.
    unsigned Idx = 0, N = Record.size();
    while (Idx < N) {
      // Read information about the AST file.
      ModuleKind ImportedKind = (ModuleKind)Record[Idx++];
      // The import location will be the local one for now; we will adjust
      // all import locations of module imports after the global source
      // location info are setup, in ReadAST.
      SourceLocation ImportLoc =
          ReadUntranslatedSourceLocation(Record[Idx++]);
      off_t StoredSize = (off_t)Record[Idx++];
      time_t StoredModTime = (time_t)Record[Idx++];
      auto FirstSignatureByte = Record.begin() + Idx;
      ASTFileSignature StoredSignature = ASTFileSignature::create(
          FirstSignatureByte, FirstSignatureByte + ASTFileSignature::size);
      Idx += ASTFileSignature::size;

      std::string ImportedName = ReadString(Record, Idx);
      std::string ImportedFile;

      // For prebuilt and explicit modules first consult the file map for
      // an override. Note that here we don't search prebuilt module
      // directories, only the explicit name to file mappings. Also, we will
      // still verify the size/signature making sure it is essentially the
      // same file but perhaps in a different location.
      if (ImportedKind == MK_PrebuiltModule || ImportedKind == MK_ExplicitModule)
        ImportedFile = PP.getHeaderSearchInfo().getPrebuiltModuleFileName(
          ImportedName, /*FileMapOnly*/ true);

      if (ImportedFile.empty())
        // Use BaseDirectoryAsWritten to ensure we use the same path in the
        // ModuleCache as when writing.
        ImportedFile = ReadPath(BaseDirectoryAsWritten, Record, Idx);
      else
        SkipPath(Record, Idx);

      // If our client can't cope with us being out of date, we can't cope with
      // our dependency being missing.
      unsigned Capabilities = ClientLoadCapabilities;
      if ((ClientLoadCapabilities & ARR_OutOfDate) == 0)
        Capabilities &= ~ARR_Missing;

      // Load the AST file.
      auto Result = ReadASTCore(ImportedFile, ImportedKind, ImportLoc, &F,
                                Loaded, StoredSize, StoredModTime,
                                StoredSignature, Capabilities);

      // If we diagnosed a problem, produce a backtrace.
      bool recompilingFinalized =
          Result == OutOfDate && (Capabilities & ARR_OutOfDate) &&
          getModuleManager().getModuleCache().isPCMFinal(F.FileName);
      if (isDiagnosedResult(Result, Capabilities) || recompilingFinalized)
        Diag(diag::note_module_file_imported_by)
            << F.FileName << !F.ModuleName.empty() << F.ModuleName;
      if (recompilingFinalized)
        Diag(diag::note_module_file_conflict);

      switch (Result) {
      case Failure: return Failure;
        // If we have to ignore the dependency, we'll have to ignore this too.
      case Missing:
      case OutOfDate: return OutOfDate;
      case VersionMismatch: return VersionMismatch;
      case ConfigurationMismatch: return ConfigurationMismatch;
      case HadErrors: return HadErrors;
      case Success: break;
      }
    }
    break;
  }

  case ORIGINAL_FILE:
    F.OriginalSourceFileID = FileID::get(Record[0]);
    F.ActualOriginalSourceFileName = std::string(Blob);
    F.OriginalSourceFileName = F.ActualOriginalSourceFileName;
    ResolveImportedPath(F, F.OriginalSourceFileName);
    break;

  case ORIGINAL_FILE_ID:
    F.OriginalSourceFileID = FileID::get(Record[0]);
    break;

  case ORIGINAL_PCH_DIR:
    F.OriginalDir = std::string(Blob);
    break;

  case MODULE_NAME:
    F.ModuleName = std::string(Blob);
    Diag(diag::remark_module_import)
        << F.ModuleName << F.FileName << (ImportedBy ? true : false)
        << (ImportedBy ? StringRef(ImportedBy->ModuleName) : StringRef());
    if (Listener)
      Listener->ReadModuleName(F.ModuleName);

    // Validate the AST as soon as we have a name so we can exit early on
    // failure.
    if (ASTReadResult Result = readUnhashedControlBlockOnce())
      return Result;

    break;

  case MODULE_DIRECTORY: {
    // Save the BaseDirectory as written in the PCM for computing the module
    // filename for the ModuleCache.
    BaseDirectoryAsWritten = Blob;
    assert(!F.ModuleName.empty() &&((void)0)
           "MODULE_DIRECTORY found before MODULE_NAME")((void)0);
    // If we've already loaded a module map file covering this module, we may
    // have a better path for it (relative to the current build).
    Module *M = PP.getHeaderSearchInfo().lookupModule(
        F.ModuleName, /*AllowSearch*/ true,
        /*AllowExtraModuleMapSearch*/ true);
    if (M && M->Directory) {
      // If we're implicitly loading a module, the base directory can't
      // change between the build and use.
      // Don't emit module relocation error if we have -fno-validate-pch
      if (!bool(PP.getPreprocessorOpts().DisablePCHOrModuleValidation &
                DisableValidationForModuleKind::Module) &&
          F.Kind != MK_ExplicitModule && F.Kind != MK_PrebuiltModule) {
        auto BuildDir = PP.getFileManager().getDirectory(Blob);
        if (!BuildDir || *BuildDir != M->Directory) {
          if (!canRecoverFromOutOfDate(F.FileName, ClientLoadCapabilities))
            Diag(diag::err_imported_module_relocated)
                << F.ModuleName << Blob << M->Directory->getName();
          return OutOfDate;
        }
      }
      F.BaseDirectory = std::string(M->Directory->getName());
    } else {
      F.BaseDirectory = std::string(Blob);
    }
    break;
  }

  case MODULE_MAP_FILE:
    if (ASTReadResult Result =
            ReadModuleMapFileBlock(Record, F, ImportedBy, ClientLoadCapabilities))
      return Result;
    break;

  case INPUT_FILE_OFFSETS:
    NumInputs = Record[0];
    NumUserInputs = Record[1];
    F.InputFileOffsets =
        (const llvm::support::unaligned_uint64_t *)Blob.data();
    F.InputFilesLoaded.resize(NumInputs);
    F.NumUserInputFiles = NumUserInputs;
    break;
  }
}
2955}

2957ASTReader::ASTReadResult
2958ASTReader::ReadASTBlock(ModuleFile &F, unsigned ClientLoadCapabilities) {
BitstreamCursor &Stream = F.Stream;

if (llvm::Error Err = Stream.EnterSubBlock(AST_BLOCK_ID)) {
  Error(std::move(Err));
  return Failure;
}
F.ASTBlockStartOffset = Stream.GetCurrentBitNo();

// Read all of the records and blocks for the AST file.
RecordData Record;
while (true) {
  Expected<llvm::BitstreamEntry> MaybeEntry = Stream.advance();
  if (!MaybeEntry) {
    Error(MaybeEntry.takeError());
    return Failure;
  }
  llvm::BitstreamEntry Entry = MaybeEntry.get();

  switch (Entry.Kind) {
  case llvm::BitstreamEntry::Error:
    Error("error at end of module block in AST file");
    return Failure;
  case llvm::BitstreamEntry::EndBlock:
    // Outside of C++, we do not store a lookup map for the translation unit.
    // Instead, mark it as needing a lookup map to be built if this module
    // contains any declarations lexically within it (which it always does!).
    // This usually has no cost, since we very rarely need the lookup map for
    // the translation unit outside C++.
    if (ASTContext *Ctx = ContextObj) {
      DeclContext *DC = Ctx->getTranslationUnitDecl();
      if (DC->hasExternalLexicalStorage() && !Ctx->getLangOpts().CPlusPlus)
        DC->setMustBuildLookupTable();
    }

    return Success;
  case llvm::BitstreamEntry::SubBlock:
    switch (Entry.ID) {
    case DECLTYPES_BLOCK_ID:
      // We lazily load the decls block, but we want to set up the
      // DeclsCursor cursor to point into it.  Clone our current bitcode
      // cursor to it, enter the block and read the abbrevs in that block.
      // With the main cursor, we just skip over it.
      F.DeclsCursor = Stream;
      if (llvm::Error Err = Stream.SkipBlock()) {
        Error(std::move(Err));
        return Failure;
      }
      if (ReadBlockAbbrevs(F.DeclsCursor, DECLTYPES_BLOCK_ID,
                           &F.DeclsBlockStartOffset)) {
        Error("malformed block record in AST file");
        return Failure;
      }
      break;

    case PREPROCESSOR_BLOCK_ID:
      F.MacroCursor = Stream;
      if (!PP.getExternalSource())
        PP.setExternalSource(this);

      if (llvm::Error Err = Stream.SkipBlock()) {
        Error(std::move(Err));
        return Failure;
      }
      if (ReadBlockAbbrevs(F.MacroCursor, PREPROCESSOR_BLOCK_ID)) {
        Error("malformed block record in AST file");
        return Failure;
      }
      F.MacroStartOffset = F.MacroCursor.GetCurrentBitNo();
      break;

    case PREPROCESSOR_DETAIL_BLOCK_ID:
      F.PreprocessorDetailCursor = Stream;

      if (llvm::Error Err = Stream.SkipBlock()) {
        Error(std::move(Err));
        return Failure;
      }
      if (ReadBlockAbbrevs(F.PreprocessorDetailCursor,
                           PREPROCESSOR_DETAIL_BLOCK_ID)) {
        Error("malformed preprocessor detail record in AST file");
        return Failure;
      }
      F.PreprocessorDetailStartOffset
      = F.PreprocessorDetailCursor.GetCurrentBitNo();

      if (!PP.getPreprocessingRecord())
        PP.createPreprocessingRecord();
      if (!PP.getPreprocessingRecord()->getExternalSource())
        PP.getPreprocessingRecord()->SetExternalSource(*this);
      break;

    case SOURCE_MANAGER_BLOCK_ID:
      if (ReadSourceManagerBlock(F))
        return Failure;
      break;

    case SUBMODULE_BLOCK_ID:
      if (ASTReadResult Result =
              ReadSubmoduleBlock(F, ClientLoadCapabilities))
        return Result;
      break;

    case COMMENTS_BLOCK_ID: {
      BitstreamCursor C = Stream;

      if (llvm::Error Err = Stream.SkipBlock()) {
        Error(std::move(Err));
        return Failure;
      }
      if (ReadBlockAbbrevs(C, COMMENTS_BLOCK_ID)) {
        Error("malformed comments block in AST file");
        return Failure;
      }
      CommentsCursors.push_back(std::make_pair(C, &F));
      break;
    }

    default:
      if (llvm::Error Err = Stream.SkipBlock()) {
        Error(std::move(Err));
        return Failure;
      }
      break;
    }
    continue;

  case llvm::BitstreamEntry::Record:
    // The interesting case.
    break;
  }

  // Read and process a record.
  Record.clear();
  StringRef Blob;
  Expected<unsigned> MaybeRecordType =
      Stream.readRecord(Entry.ID, Record, &Blob);
  if (!MaybeRecordType) {
    Error(MaybeRecordType.takeError());
    return Failure;
  }
  ASTRecordTypes RecordType = (ASTRecordTypes)MaybeRecordType.get();

  // If we're not loading an AST context, we don't care about most records.
  if (!ContextObj) {
    switch (RecordType) {
    case IDENTIFIER_TABLE:
    case IDENTIFIER_OFFSET:
    case INTERESTING_IDENTIFIERS:
    case STATISTICS:
    case PP_CONDITIONAL_STACK:
    case PP_COUNTER_VALUE:
    case SOURCE_LOCATION_OFFSETS:
    case MODULE_OFFSET_MAP:
    case SOURCE_MANAGER_LINE_TABLE:
    case SOURCE_LOCATION_PRELOADS:
    case PPD_ENTITIES_OFFSETS:
    case HEADER_SEARCH_TABLE:
    case IMPORTED_MODULES:
    case MACRO_OFFSET:
      break;
    default:
      continue;
    }
  }

  switch (RecordType) {
  default:  // Default behavior: ignore.
    break;

  case TYPE_OFFSET: {
    if (F.LocalNumTypes != 0) {
      Error("duplicate TYPE_OFFSET record in AST file");
      return Failure;
    }
    F.TypeOffsets = reinterpret_cast<const UnderalignedInt64 *>(Blob.data());
    F.LocalNumTypes = Record[0];
    unsigned LocalBaseTypeIndex = Record[1];
    F.BaseTypeIndex = getTotalNumTypes();

    if (F.LocalNumTypes > 0) {
      // Introduce the global -> local mapping for types within this module.
      GlobalTypeMap.insert(std::make_pair(getTotalNumTypes(), &F));

      // Introduce the local -> global mapping for types within this module.
      F.TypeRemap.insertOrReplace(
        std::make_pair(LocalBaseTypeIndex,
                       F.BaseTypeIndex - LocalBaseTypeIndex));

      TypesLoaded.resize(TypesLoaded.size() + F.LocalNumTypes);
    }
    break;
  }

  case DECL_OFFSET: {
    if (F.LocalNumDecls != 0) {
      Error("duplicate DECL_OFFSET record in AST file");
      return Failure;
    }
    F.DeclOffsets = (const DeclOffset *)Blob.data();
    F.LocalNumDecls = Record[0];
    unsigned LocalBaseDeclID = Record[1];
    F.BaseDeclID = getTotalNumDecls();

    if (F.LocalNumDecls > 0) {
      // Introduce the global -> local mapping for declarations within this
      // module.
      GlobalDeclMap.insert(
        std::make_pair(getTotalNumDecls() + NUM_PREDEF_DECL_IDS, &F));

      // Introduce the local -> global mapping for declarations within this
      // module.
      F.DeclRemap.insertOrReplace(
        std::make_pair(LocalBaseDeclID, F.BaseDeclID - LocalBaseDeclID));

      // Introduce the global -> local mapping for declarations within this
      // module.
      F.GlobalToLocalDeclIDs[&F] = LocalBaseDeclID;

      DeclsLoaded.resize(DeclsLoaded.size() + F.LocalNumDecls);
    }
    break;
  }

  case TU_UPDATE_LEXICAL: {
    DeclContext *TU = ContextObj->getTranslationUnitDecl();
    LexicalContents Contents(
        reinterpret_cast<const llvm::support::unaligned_uint32_t *>(
            Blob.data()),
        static_cast<unsigned int>(Blob.size() / 4));
    TULexicalDecls.push_back(std::make_pair(&F, Contents));
    TU->setHasExternalLexicalStorage(true);
    break;
  }

  case UPDATE_VISIBLE: {
    unsigned Idx = 0;
    serialization::DeclID ID = ReadDeclID(F, Record, Idx);
    auto *Data = (const unsigned char*)Blob.data();
    PendingVisibleUpdates[ID].push_back(PendingVisibleUpdate{&F, Data});
    // If we've already loaded the decl, perform the updates when we finish
    // loading this block.
    if (Decl *D = GetExistingDecl(ID))
      PendingUpdateRecords.push_back(
          PendingUpdateRecord(ID, D, /*JustLoaded=*/false));
    break;
  }

  case IDENTIFIER_TABLE:
    F.IdentifierTableData =
        reinterpret_cast<const unsigned char *>(Blob.data());
    if (Record[0]) {
      F.IdentifierLookupTable = ASTIdentifierLookupTable::Create(
          F.IdentifierTableData + Record[0],
          F.IdentifierTableData + sizeof(uint32_t),
          F.IdentifierTableData,
          ASTIdentifierLookupTrait(*this, F));

      PP.getIdentifierTable().setExternalIdentifierLookup(this);
    }
    break;

  case IDENTIFIER_OFFSET: {
    if (F.LocalNumIdentifiers != 0) {
      Error("duplicate IDENTIFIER_OFFSET record in AST file");
      return Failure;
    }
    F.IdentifierOffsets = (const uint32_t *)Blob.data();
    F.LocalNumIdentifiers = Record[0];
    unsigned LocalBaseIdentifierID = Record[1];
    F.BaseIdentifierID = getTotalNumIdentifiers();

    if (F.LocalNumIdentifiers > 0) {
      // Introduce the global -> local mapping for identifiers within this
      // module.
      GlobalIdentifierMap.insert(std::make_pair(getTotalNumIdentifiers() + 1,
                                                &F));

      // Introduce the local -> global mapping for identifiers within this
      // module.
      F.IdentifierRemap.insertOrReplace(
        std::make_pair(LocalBaseIdentifierID,
                       F.BaseIdentifierID - LocalBaseIdentifierID));

      IdentifiersLoaded.resize(IdentifiersLoaded.size()
                               + F.LocalNumIdentifiers);
    }
    break;
  }

  case INTERESTING_IDENTIFIERS:
    F.PreloadIdentifierOffsets.assign(Record.begin(), Record.end());
    break;

  case EAGERLY_DESERIALIZED_DECLS:
    // FIXME: Skip reading this record if our ASTConsumer doesn't care
    // about "interesting" decls (for instance, if we're building a module).
    for (unsigned I = 0, N = Record.size(); I != N; ++I)
      EagerlyDeserializedDecls.push_back(getGlobalDeclID(F, Record[I]));
    break;

  case MODULAR_CODEGEN_DECLS:
    // FIXME: Skip reading this record if our ASTConsumer doesn't care about
    // them (ie: if we're not codegenerating this module).
    if (F.Kind == MK_MainFile ||
        getContext().getLangOpts().BuildingPCHWithObjectFile)
      for (unsigned I = 0, N = Record.size(); I != N; ++I)
        EagerlyDeserializedDecls.push_back(getGlobalDeclID(F, Record[I]));
    break;

  case SPECIAL_TYPES:
    if (SpecialTypes.empty()) {
      for (unsigned I = 0, N = Record.size(); I != N; ++I)
        SpecialTypes.push_back(getGlobalTypeID(F, Record[I]));
      break;
    }

    if (SpecialTypes.size() != Record.size()) {
      Error("invalid special-types record");
      return Failure;
    }

    for (unsigned I = 0, N = Record.size(); I != N; ++I) {
      serialization::TypeID ID = getGlobalTypeID(F, Record[I]);
      if (!SpecialTypes[I])
        SpecialTypes[I] = ID;
      // FIXME: If ID && SpecialTypes[I] != ID, do we need a separate
      // merge step?
    }
    break;

  case STATISTICS:
    TotalNumStatements += Record[0];
    TotalNumMacros += Record[1];
    TotalLexicalDeclContexts += Record[2];
    TotalVisibleDeclContexts += Record[3];
    break;

  case UNUSED_FILESCOPED_DECLS:
    for (unsigned I = 0, N = Record.size(); I != N; ++I)
      UnusedFileScopedDecls.push_back(getGlobalDeclID(F, Record[I]));
    break;

  case DELEGATING_CTORS:
    for (unsigned I = 0, N = Record.size(); I != N; ++I)
      DelegatingCtorDecls.push_back(getGlobalDeclID(F, Record[I]));
    break;

  case WEAK_UNDECLARED_IDENTIFIERS:
    if (Record.size() % 4 != 0) {
      Error("invalid weak identifiers record");
      return Failure;
    }

    // FIXME: Ignore weak undeclared identifiers from non-original PCH
    // files. This isn't the way to do it :)
    WeakUndeclaredIdentifiers.clear();

    // Translate the weak, undeclared identifiers into global IDs.
    for (unsigned I = 0, N = Record.size(); I < N; /* in loop */) {
      WeakUndeclaredIdentifiers.push_back(
        getGlobalIdentifierID(F, Record[I++]));
      WeakUndeclaredIdentifiers.push_back(
        getGlobalIdentifierID(F, Record[I++]));
      WeakUndeclaredIdentifiers.push_back(
        ReadSourceLocation(F, Record, I).getRawEncoding());
      WeakUndeclaredIdentifiers.push_back(Record[I++]);
    }
    break;

  case SELECTOR_OFFSETS: {
    F.SelectorOffsets = (const uint32_t *)Blob.data();
    F.LocalNumSelectors = Record[0];
    unsigned LocalBaseSelectorID = Record[1];
    F.BaseSelectorID = getTotalNumSelectors();

    if (F.LocalNumSelectors > 0) {
      // Introduce the global -> local mapping for selectors within this
      // module.
      GlobalSelectorMap.insert(std::make_pair(getTotalNumSelectors()+1, &F));

      // Introduce the local -> global mapping for selectors within this
      // module.
      F.SelectorRemap.insertOrReplace(
        std::make_pair(LocalBaseSelectorID,
                       F.BaseSelectorID - LocalBaseSelectorID));

      SelectorsLoaded.resize(SelectorsLoaded.size() + F.LocalNumSelectors);
    }
    break;
  }

  case METHOD_POOL:
    F.SelectorLookupTableData = (const unsigned char *)Blob.data();
    if (Record[0])
      F.SelectorLookupTable
        = ASTSelectorLookupTable::Create(
                      F.SelectorLookupTableData + Record[0],
                      F.SelectorLookupTableData,
                      ASTSelectorLookupTrait(*this, F));
    TotalNumMethodPoolEntries += Record[1];
    break;

  case REFERENCED_SELECTOR_POOL:
    if (!Record.empty()) {
      for (unsigned Idx = 0, N = Record.size() - 1; Idx < N; /* in loop */) {
        ReferencedSelectorsData.push_back(getGlobalSelectorID(F,
                                                              Record[Idx++]));
        ReferencedSelectorsData.push_back(ReadSourceLocation(F, Record, Idx).
                                            getRawEncoding());
      }
    }
    break;

  case PP_CONDITIONAL_STACK:
    if (!Record.empty()) {
      unsigned Idx = 0, End = Record.size() - 1;
      bool ReachedEOFWhileSkipping = Record[Idx++];
      llvm::Optional<Preprocessor::PreambleSkipInfo> SkipInfo;
      if (ReachedEOFWhileSkipping) {
        SourceLocation HashToken = ReadSourceLocation(F, Record, Idx);
        SourceLocation IfTokenLoc = ReadSourceLocation(F, Record, Idx);
        bool FoundNonSkipPortion = Record[Idx++];
        bool FoundElse = Record[Idx++];
        SourceLocation ElseLoc = ReadSourceLocation(F, Record, Idx);
        SkipInfo.emplace(HashToken, IfTokenLoc, FoundNonSkipPortion,
                         FoundElse, ElseLoc);
      }
      SmallVector<PPConditionalInfo, 4> ConditionalStack;
      while (Idx < End) {
        auto Loc = ReadSourceLocation(F, Record, Idx);
        bool WasSkipping = Record[Idx++];
        bool FoundNonSkip = Record[Idx++];
        bool FoundElse = Record[Idx++];
        ConditionalStack.push_back(
            {Loc, WasSkipping, FoundNonSkip, FoundElse});
      }
      PP.setReplayablePreambleConditionalStack(ConditionalStack, SkipInfo);
    }
    break;

  case PP_COUNTER_VALUE:
    if (!Record.empty() && Listener)
      Listener->ReadCounter(F, Record[0]);
    break;

  case FILE_SORTED_DECLS:
    F.FileSortedDecls = (const DeclID *)Blob.data();
    F.NumFileSortedDecls = Record[0];
    break;

  case SOURCE_LOCATION_OFFSETS: {
    F.SLocEntryOffsets = (const uint32_t *)Blob.data();
    F.LocalNumSLocEntries = Record[0];
    SourceLocation::UIntTy SLocSpaceSize = Record[1];
    F.SLocEntryOffsetsBase = Record[2] + F.SourceManagerBlockStartOffset;
    std::tie(F.SLocEntryBaseID, F.SLocEntryBaseOffset) =
        SourceMgr.AllocateLoadedSLocEntries(F.LocalNumSLocEntries,
                                            SLocSpaceSize);
    if (!F.SLocEntryBaseID) {
      Error("ran out of source locations");
      break;
    }
    // Make our entry in the range map. BaseID is negative and growing, so
    // we invert it. Because we invert it, though, we need the other end of
    // the range.
    unsigned RangeStart =
        unsigned(-F.SLocEntryBaseID) - F.LocalNumSLocEntries + 1;
    GlobalSLocEntryMap.insert(std::make_pair(RangeStart, &F));
    F.FirstLoc = SourceLocation::getFromRawEncoding(F.SLocEntryBaseOffset);

    // SLocEntryBaseOffset is lower than MaxLoadedOffset and decreasing.
    assert((F.SLocEntryBaseOffset & SourceLocation::MacroIDBit) == 0)((void)0);
    GlobalSLocOffsetMap.insert(
        std::make_pair(SourceManager::MaxLoadedOffset - F.SLocEntryBaseOffset
                         - SLocSpaceSize,&F));

    // Initialize the remapping table.
    // Invalid stays invalid.
    F.SLocRemap.insertOrReplace(std::make_pair(0U, 0));
    // This module. Base was 2 when being compiled.
    F.SLocRemap.insertOrReplace(std::make_pair(
        2U, static_cast<SourceLocation::IntTy>(F.SLocEntryBaseOffset - 2)));

    TotalNumSLocEntries += F.LocalNumSLocEntries;
    break;
  }

  case MODULE_OFFSET_MAP:
    F.ModuleOffsetMap = Blob;
    break;

  case SOURCE_MANAGER_LINE_TABLE:
    if (ParseLineTable(F, Record)) {
      Error("malformed SOURCE_MANAGER_LINE_TABLE in AST file");
      return Failure;
    }
    break;

  case SOURCE_LOCATION_PRELOADS: {
    // Need to transform from the local view (1-based IDs) to the global view,
    // which is based off F.SLocEntryBaseID.
    if (!F.PreloadSLocEntries.empty()) {
      Error("Multiple SOURCE_LOCATION_PRELOADS records in AST file");
      return Failure;
    }

    F.PreloadSLocEntries.swap(Record);
    break;
  }

  case EXT_VECTOR_DECLS:
    for (unsigned I = 0, N = Record.size(); I != N; ++I)
      ExtVectorDecls.push_back(getGlobalDeclID(F, Record[I]));
    break;

  case VTABLE_USES:
    if (Record.size() % 3 != 0) {
      Error("Invalid VTABLE_USES record");
      return Failure;
    }

    // Later tables overwrite earlier ones.
    // FIXME: Modules will have some trouble with this. This is clearly not
    // the right way to do this.
    VTableUses.clear();

    for (unsigned Idx = 0, N = Record.size(); Idx != N; /* In loop */) {
      VTableUses.push_back(getGlobalDeclID(F, Record[Idx++]));
      VTableUses.push_back(
        ReadSourceLocation(F, Record, Idx).getRawEncoding());
      VTableUses.push_back(Record[Idx++]);
    }
    break;

  case PENDING_IMPLICIT_INSTANTIATIONS:
    if (PendingInstantiations.size() % 2 != 0) {
      Error("Invalid existing PendingInstantiations");
      return Failure;
    }

    if (Record.size() % 2 != 0) {
      Error("Invalid PENDING_IMPLICIT_INSTANTIATIONS block");
      return Failure;
    }

    for (unsigned I = 0, N = Record.size(); I != N; /* in loop */) {
      PendingInstantiations.push_back(getGlobalDeclID(F, Record[I++]));
      PendingInstantiations.push_back(
        ReadSourceLocation(F, Record, I).getRawEncoding());
    }
    break;

  case SEMA_DECL_REFS:
    if (Record.size() != 3) {
      Error("Invalid SEMA_DECL_REFS block");
      return Failure;
    }
    for (unsigned I = 0, N = Record.size(); I != N; ++I)
      SemaDeclRefs.push_back(getGlobalDeclID(F, Record[I]));
    break;

  case PPD_ENTITIES_OFFSETS: {
    F.PreprocessedEntityOffsets = (const PPEntityOffset *)Blob.data();
    assert(Blob.size() % sizeof(PPEntityOffset) == 0)((void)0);
    F.NumPreprocessedEntities = Blob.size() / sizeof(PPEntityOffset);

    unsigned LocalBasePreprocessedEntityID = Record[0];

    unsigned StartingID;
    if (!PP.getPreprocessingRecord())
      PP.createPreprocessingRecord();
    if (!PP.getPreprocessingRecord()->getExternalSource())
      PP.getPreprocessingRecord()->SetExternalSource(*this);
    StartingID
      = PP.getPreprocessingRecord()
          ->allocateLoadedEntities(F.NumPreprocessedEntities);
    F.BasePreprocessedEntityID = StartingID;

    if (F.NumPreprocessedEntities > 0) {
      // Introduce the global -> local mapping for preprocessed entities in
      // this module.
      GlobalPreprocessedEntityMap.insert(std::make_pair(StartingID, &F));

      // Introduce the local -> global mapping for preprocessed entities in
      // this module.
      F.PreprocessedEntityRemap.insertOrReplace(
        std::make_pair(LocalBasePreprocessedEntityID,
          F.BasePreprocessedEntityID - LocalBasePreprocessedEntityID));
    }

    break;
  }

  case PPD_SKIPPED_RANGES: {
    F.PreprocessedSkippedRangeOffsets = (const PPSkippedRange*)Blob.data();
    assert(Blob.size() % sizeof(PPSkippedRange) == 0)((void)0);
    F.NumPreprocessedSkippedRanges = Blob.size() / sizeof(PPSkippedRange);

    if (!PP.getPreprocessingRecord())
      PP.createPreprocessingRecord();
    if (!PP.getPreprocessingRecord()->getExternalSource())
      PP.getPreprocessingRecord()->SetExternalSource(*this);
    F.BasePreprocessedSkippedRangeID = PP.getPreprocessingRecord()
        ->allocateSkippedRanges(F.NumPreprocessedSkippedRanges);

    if (F.NumPreprocessedSkippedRanges > 0)
      GlobalSkippedRangeMap.insert(
          std::make_pair(F.BasePreprocessedSkippedRangeID, &F));
    break;
  }

  case DECL_UPDATE_OFFSETS:
    if (Record.size() % 2 != 0) {
      Error("invalid DECL_UPDATE_OFFSETS block in AST file");
      return Failure;
    }
    for (unsigned I = 0, N = Record.size(); I != N; I += 2) {
      GlobalDeclID ID = getGlobalDeclID(F, Record[I]);
      DeclUpdateOffsets[ID].push_back(std::make_pair(&F, Record[I + 1]));

      // If we've already loaded the decl, perform the updates when we finish
      // loading this block.
      if (Decl *D = GetExistingDecl(ID))
        PendingUpdateRecords.push_back(
            PendingUpdateRecord(ID, D, /*JustLoaded=*/false));
    }
    break;

  case OBJC_CATEGORIES_MAP:
    if (F.LocalNumObjCCategoriesInMap != 0) {
      Error("duplicate OBJC_CATEGORIES_MAP record in AST file");
      return Failure;
    }

    F.LocalNumObjCCategoriesInMap = Record[0];
    F.ObjCCategoriesMap = (const ObjCCategoriesInfo *)Blob.data();
    break;

  case OBJC_CATEGORIES:
    F.ObjCCategories.swap(Record);
    break;

  case CUDA_SPECIAL_DECL_REFS:
    // Later tables overwrite earlier ones.
    // FIXME: Modules will have trouble with this.
    CUDASpecialDeclRefs.clear();
    for (unsigned I = 0, N = Record.size(); I != N; ++I)
      CUDASpecialDeclRefs.push_back(getGlobalDeclID(F, Record[I]));
    break;

  case HEADER_SEARCH_TABLE:
    F.HeaderFileInfoTableData = Blob.data();
    F.LocalNumHeaderFileInfos = Record[1];
    if (Record[0]) {
      F.HeaderFileInfoTable
        = HeaderFileInfoLookupTable::Create(
                 (const unsigned char *)F.HeaderFileInfoTableData + Record[0],
                 (const unsigned char *)F.HeaderFileInfoTableData,
                 HeaderFileInfoTrait(*this, F,
                                     &PP.getHeaderSearchInfo(),
                                     Blob.data() + Record[2]));

      PP.getHeaderSearchInfo().SetExternalSource(this);
      if (!PP.getHeaderSearchInfo().getExternalLookup())
        PP.getHeaderSearchInfo().SetExternalLookup(this);
    }
    break;

  case FP_PRAGMA_OPTIONS:
    // Later tables overwrite earlier ones.
    FPPragmaOptions.swap(Record);
    break;

  case OPENCL_EXTENSIONS:
    for (unsigned I = 0, E = Record.size(); I != E; ) {
      auto Name = ReadString(Record, I);
      auto &OptInfo = OpenCLExtensions.OptMap[Name];
      OptInfo.Supported = Record[I++] != 0;
      OptInfo.Enabled = Record[I++] != 0;
      OptInfo.WithPragma = Record[I++] != 0;
      OptInfo.Avail = Record[I++];
      OptInfo.Core = Record[I++];
      OptInfo.Opt = Record[I++];
    }
    break;

  case TENTATIVE_DEFINITIONS:
    for (unsigned I = 0, N = Record.size(); I != N; ++I)
      TentativeDefinitions.push_back(getGlobalDeclID(F, Record[I]));
    break;

  case KNOWN_NAMESPACES:
    for (unsigned I = 0, N = Record.size(); I != N; ++I)
      KnownNamespaces.push_back(getGlobalDeclID(F, Record[I]));
    break;

  case UNDEFINED_BUT_USED:
    if (UndefinedButUsed.size() % 2 != 0) {
      Error("Invalid existing UndefinedButUsed");
      return Failure;
    }

    if (Record.size() % 2 != 0) {
      Error("invalid undefined-but-used record");
      return Failure;
    }
    for (unsigned I = 0, N = Record.size(); I != N; /* in loop */) {
      UndefinedButUsed.push_back(getGlobalDeclID(F, Record[I++]));
      UndefinedButUsed.push_back(
          ReadSourceLocation(F, Record, I).getRawEncoding());
    }
    break;

  case DELETE_EXPRS_TO_ANALYZE:
    for (unsigned I = 0, N = Record.size(); I != N;) {
      DelayedDeleteExprs.push_back(getGlobalDeclID(F, Record[I++]));
      const uint64_t Count = Record[I++];
      DelayedDeleteExprs.push_back(Count);
      for (uint64_t C = 0; C < Count; ++C) {
        DelayedDeleteExprs.push_back(ReadSourceLocation(F, Record, I).getRawEncoding());
        bool IsArrayForm = Record[I++] == 1;
        DelayedDeleteExprs.push_back(IsArrayForm);
      }
    }
    break;

  case IMPORTED_MODULES:
    if (!F.isModule()) {
      // If we aren't loading a module (which has its own exports), make
      // all of the imported modules visible.
      // FIXME: Deal with macros-only imports.
      for (unsigned I = 0, N = Record.size(); I != N; /**/) {
        unsigned GlobalID = getGlobalSubmoduleID(F, Record[I++]);
        SourceLocation Loc = ReadSourceLocation(F, Record, I);
        if (GlobalID) {
          ImportedModules.push_back(ImportedSubmodule(GlobalID, Loc));
          if (DeserializationListener)
            DeserializationListener->ModuleImportRead(GlobalID, Loc);
        }
      }
    }
    break;

  case MACRO_OFFSET: {
    if (F.LocalNumMacros != 0) {
      Error("duplicate MACRO_OFFSET record in AST file");
      return Failure;
    }
    F.MacroOffsets = (const uint32_t *)Blob.data();
    F.LocalNumMacros = Record[0];
    unsigned LocalBaseMacroID = Record[1];
    F.MacroOffsetsBase = Record[2] + F.ASTBlockStartOffset;
    F.BaseMacroID = getTotalNumMacros();

    if (F.LocalNumMacros > 0) {
      // Introduce the global -> local mapping for macros within this module.
      GlobalMacroMap.insert(std::make_pair(getTotalNumMacros() + 1, &F));

      // Introduce the local -> global mapping for macros within this module.
      F.MacroRemap.insertOrReplace(
        std::make_pair(LocalBaseMacroID,
                       F.BaseMacroID - LocalBaseMacroID));

      MacrosLoaded.resize(MacrosLoaded.size() + F.LocalNumMacros);
    }
    break;
  }

  case LATE_PARSED_TEMPLATE:
    LateParsedTemplates.emplace_back(
        std::piecewise_construct, std::forward_as_tuple(&F),
        std::forward_as_tuple(Record.begin(), Record.end()));
    break;

  case OPTIMIZE_PRAGMA_OPTIONS:
    if (Record.size() != 1) {
      Error("invalid pragma optimize record");
      return Failure;
    }
    OptimizeOffPragmaLocation = ReadSourceLocation(F, Record[0]);
    break;

  case MSSTRUCT_PRAGMA_OPTIONS:
    if (Record.size() != 1) {
      Error("invalid pragma ms_struct record");
      return Failure;
    }
    PragmaMSStructState = Record[0];
    break;

  case POINTERS_TO_MEMBERS_PRAGMA_OPTIONS:
    if (Record.size() != 2) {
      Error("invalid pragma ms_struct record");
      return Failure;
    }
    PragmaMSPointersToMembersState = Record[0];
    PointersToMembersPragmaLocation = ReadSourceLocation(F, Record[1]);
    break;

  case UNUSED_LOCAL_TYPEDEF_NAME_CANDIDATES:
    for (unsigned I = 0, N = Record.size(); I != N; ++I)
      UnusedLocalTypedefNameCandidates.push_back(
          getGlobalDeclID(F, Record[I]));
    break;

  case CUDA_PRAGMA_FORCE_HOST_DEVICE_DEPTH:
    if (Record.size() != 1) {
      Error("invalid cuda pragma options record");
      return Failure;
    }
    ForceCUDAHostDeviceDepth = Record[0];
    break;

  case ALIGN_PACK_PRAGMA_OPTIONS: {
    if (Record.size() < 3) {
      Error("invalid pragma pack record");
      return Failure;
    }
    PragmaAlignPackCurrentValue = ReadAlignPackInfo(Record[0]);
    PragmaAlignPackCurrentLocation = ReadSourceLocation(F, Record[1]);
    unsigned NumStackEntries = Record[2];
    unsigned Idx = 3;
    // Reset the stack when importing a new module.
    PragmaAlignPackStack.clear();
    for (unsigned I = 0; I < NumStackEntries; ++I) {
      PragmaAlignPackStackEntry Entry;
      Entry.Value = ReadAlignPackInfo(Record[Idx++]);
      Entry.Location = ReadSourceLocation(F, Record[Idx++]);
      Entry.PushLocation = ReadSourceLocation(F, Record[Idx++]);
      PragmaAlignPackStrings.push_back(ReadString(Record, Idx));
      Entry.SlotLabel = PragmaAlignPackStrings.back();
      PragmaAlignPackStack.push_back(Entry);
    }
    break;
  }

  case FLOAT_CONTROL_PRAGMA_OPTIONS: {
    if (Record.size() < 3) {
      Error("invalid pragma pack record");
      return Failure;
    }
    FpPragmaCurrentValue = FPOptionsOverride::getFromOpaqueInt(Record[0]);
    FpPragmaCurrentLocation = ReadSourceLocation(F, Record[1]);
    unsigned NumStackEntries = Record[2];
    unsigned Idx = 3;
    // Reset the stack when importing a new module.
    FpPragmaStack.clear();
    for (unsigned I = 0; I < NumStackEntries; ++I) {
      FpPragmaStackEntry Entry;
      Entry.Value = FPOptionsOverride::getFromOpaqueInt(Record[Idx++]);
      Entry.Location = ReadSourceLocation(F, Record[Idx++]);
      Entry.PushLocation = ReadSourceLocation(F, Record[Idx++]);
      FpPragmaStrings.push_back(ReadString(Record, Idx));
      Entry.SlotLabel = FpPragmaStrings.back();
      FpPragmaStack.push_back(Entry);
    }
    break;
  }

  case DECLS_TO_CHECK_FOR_DEFERRED_DIAGS:
    for (unsigned I = 0, N = Record.size(); I != N; ++I)
      DeclsToCheckForDeferredDiags.insert(getGlobalDeclID(F, Record[I]));
    break;
  }
}
3824}

3826void ASTReader::ReadModuleOffsetMap(ModuleFile &F) const {
assert(!F.ModuleOffsetMap.empty() && "no module offset map to read")((void)0);

// Additional remapping information.
const unsigned char *Data = (const unsigned char*)F.ModuleOffsetMap.data();
const unsigned char *DataEnd = Data + F.ModuleOffsetMap.size();
F.ModuleOffsetMap = StringRef();

// If we see this entry before SOURCE_LOCATION_OFFSETS, add placeholders.
if (F.SLocRemap.find(0) == F.SLocRemap.end()) {
  F.SLocRemap.insert(std::make_pair(0U, 0));
  F.SLocRemap.insert(std::make_pair(2U, 1));
}

// Continuous range maps we may be updating in our module.
using SLocRemapBuilder =
    ContinuousRangeMap<SourceLocation::UIntTy, SourceLocation::IntTy,
                       2>::Builder;
using RemapBuilder = ContinuousRangeMap<uint32_t, int, 2>::Builder;
SLocRemapBuilder SLocRemap(F.SLocRemap);
RemapBuilder IdentifierRemap(F.IdentifierRemap);
RemapBuilder MacroRemap(F.MacroRemap);
RemapBuilder PreprocessedEntityRemap(F.PreprocessedEntityRemap);
RemapBuilder SubmoduleRemap(F.SubmoduleRemap);
RemapBuilder SelectorRemap(F.SelectorRemap);
RemapBuilder DeclRemap(F.DeclRemap);
RemapBuilder TypeRemap(F.TypeRemap);

while (Data < DataEnd) {
  // FIXME: Looking up dependency modules by filename is horrible. Let's
  // start fixing this with prebuilt, explicit and implicit modules and see
  // how it goes...
  using namespace llvm::support;
  ModuleKind Kind = static_cast<ModuleKind>(
    endian::readNext<uint8_t, little, unaligned>(Data));
  uint16_t Len = endian::readNext<uint16_t, little, unaligned>(Data);
  StringRef Name = StringRef((const char*)Data, Len);
  Data += Len;
  ModuleFile *OM = (Kind == MK_PrebuiltModule || Kind == MK_ExplicitModule ||
                            Kind == MK_ImplicitModule
                        ? ModuleMgr.lookupByModuleName(Name)
                        : ModuleMgr.lookupByFileName(Name));
  if (!OM) {
    std::string Msg =
        "SourceLocation remap refers to unknown module, cannot find ";
    Msg.append(std::string(Name));
    Error(Msg);
    return;
  }

  SourceLocation::UIntTy SLocOffset =
      endian::readNext<uint32_t, little, unaligned>(Data);
  uint32_t IdentifierIDOffset =
      endian::readNext<uint32_t, little, unaligned>(Data);
  uint32_t MacroIDOffset =
      endian::readNext<uint32_t, little, unaligned>(Data);
  uint32_t PreprocessedEntityIDOffset =
      endian::readNext<uint32_t, little, unaligned>(Data);
  uint32_t SubmoduleIDOffset =
      endian::readNext<uint32_t, little, unaligned>(Data);
  uint32_t SelectorIDOffset =
      endian::readNext<uint32_t, little, unaligned>(Data);
  uint32_t DeclIDOffset =
      endian::readNext<uint32_t, little, unaligned>(Data);
  uint32_t TypeIndexOffset =
      endian::readNext<uint32_t, little, unaligned>(Data);

  auto mapOffset = [&](uint32_t Offset, uint32_t BaseOffset,
                       RemapBuilder &Remap) {
    constexpr uint32_t None = std::numeric_limits<uint32_t>::max();
    if (Offset != None)
      Remap.insert(std::make_pair(Offset,
                                  static_cast<int>(BaseOffset - Offset)));
  };

  constexpr SourceLocation::UIntTy SLocNone =
      std::numeric_limits<SourceLocation::UIntTy>::max();
  if (SLocOffset != SLocNone)
    SLocRemap.insert(std::make_pair(
        SLocOffset, static_cast<SourceLocation::IntTy>(
                        OM->SLocEntryBaseOffset - SLocOffset)));

  mapOffset(IdentifierIDOffset, OM->BaseIdentifierID, IdentifierRemap);
  mapOffset(MacroIDOffset, OM->BaseMacroID, MacroRemap);
  mapOffset(PreprocessedEntityIDOffset, OM->BasePreprocessedEntityID,
            PreprocessedEntityRemap);
  mapOffset(SubmoduleIDOffset, OM->BaseSubmoduleID, SubmoduleRemap);
  mapOffset(SelectorIDOffset, OM->BaseSelectorID, SelectorRemap);
  mapOffset(DeclIDOffset, OM->BaseDeclID, DeclRemap);
  mapOffset(TypeIndexOffset, OM->BaseTypeIndex, TypeRemap);

  // Global -> local mappings.
  F.GlobalToLocalDeclIDs[OM] = DeclIDOffset;
}
3920}

3922ASTReader::ASTReadResult
3923ASTReader::ReadModuleMapFileBlock(RecordData &Record, ModuleFile &F,
                                const ModuleFile *ImportedBy,
                                unsigned ClientLoadCapabilities) {
unsigned Idx = 0;
F.ModuleMapPath = ReadPath(F, Record, Idx);

// Try to resolve ModuleName in the current header search context and
// verify that it is found in the same module map file as we saved. If the
// top-level AST file is a main file, skip this check because there is no
// usable header search context.
assert(!F.ModuleName.empty() &&((void)0)
       "MODULE_NAME should come before MODULE_MAP_FILE")((void)0);
if (F.Kind == MK_ImplicitModule && ModuleMgr.begin()->Kind != MK_MainFile) {
  // An implicitly-loaded module file should have its module listed in some
  // module map file that we've already loaded.
  Module *M = PP.getHeaderSearchInfo().lookupModule(F.ModuleName);
  auto &Map = PP.getHeaderSearchInfo().getModuleMap();
  const FileEntry *ModMap = M ? Map.getModuleMapFileForUniquing(M) : nullptr;
  // Don't emit module relocation error if we have -fno-validate-pch
  if (!bool(PP.getPreprocessorOpts().DisablePCHOrModuleValidation &
            DisableValidationForModuleKind::Module) &&
      !ModMap) {
    if (!canRecoverFromOutOfDate(F.FileName, ClientLoadCapabilities)) {
      if (auto ASTFE = M ? M->getASTFile() : None) {
        // This module was defined by an imported (explicit) module.
        Diag(diag::err_module_file_conflict) << F.ModuleName << F.FileName
                                             << ASTFE->getName();
      } else {
        // This module was built with a different module map.
        Diag(diag::err_imported_module_not_found)
            << F.ModuleName << F.FileName
            << (ImportedBy ? ImportedBy->FileName : "") << F.ModuleMapPath
            << !ImportedBy;
        // In case it was imported by a PCH, there's a chance the user is
        // just missing to include the search path to the directory containing
        // the modulemap.
        if (ImportedBy && ImportedBy->Kind == MK_PCH)
          Diag(diag::note_imported_by_pch_module_not_found)
              << llvm::sys::path::parent_path(F.ModuleMapPath);
      }
    }
    return OutOfDate;
  }

  assert(M && M->Name == F.ModuleName && "found module with different name")((void)0);

  // Check the primary module map file.
  auto StoredModMap = FileMgr.getFile(F.ModuleMapPath);
  if (!StoredModMap || *StoredModMap != ModMap) {
    assert(ModMap && "found module is missing module map file")((void)0);
    assert((ImportedBy || F.Kind == MK_ImplicitModule) &&((void)0)
           "top-level import should be verified")((void)0);
    bool NotImported = F.Kind == MK_ImplicitModule && !ImportedBy;
    if (!canRecoverFromOutOfDate(F.FileName, ClientLoadCapabilities))
      Diag(diag::err_imported_module_modmap_changed)
          << F.ModuleName << (NotImported ? F.FileName : ImportedBy->FileName)
          << ModMap->getName() << F.ModuleMapPath << NotImported;
    return OutOfDate;
  }

  llvm::SmallPtrSet<const FileEntry *, 1> AdditionalStoredMaps;
  for (unsigned I = 0, N = Record[Idx++]; I < N; ++I) {
    // FIXME: we should use input files rather than storing names.
    std::string Filename = ReadPath(F, Record, Idx);
    auto SF = FileMgr.getFile(Filename, false, false);
    if (!SF) {
      if (!canRecoverFromOutOfDate(F.FileName, ClientLoadCapabilities))
        Error("could not find file '" + Filename +"' referenced by AST file");
      return OutOfDate;
    }
    AdditionalStoredMaps.insert(*SF);
  }

  // Check any additional module map files (e.g. module.private.modulemap)
  // that are not in the pcm.
  if (auto *AdditionalModuleMaps = Map.getAdditionalModuleMapFiles(M)) {
    for (const FileEntry *ModMap : *AdditionalModuleMaps) {
      // Remove files that match
      // Note: SmallPtrSet::erase is really remove
      if (!AdditionalStoredMaps.erase(ModMap)) {
        if (!canRecoverFromOutOfDate(F.FileName, ClientLoadCapabilities))
          Diag(diag::err_module_different_modmap)
            << F.ModuleName << /*new*/0 << ModMap->getName();
        return OutOfDate;
      }
    }
  }

  // Check any additional module map files that are in the pcm, but not
  // found in header search. Cases that match are already removed.
  for (const FileEntry *ModMap : AdditionalStoredMaps) {
    if (!canRecoverFromOutOfDate(F.FileName, ClientLoadCapabilities))
      Diag(diag::err_module_different_modmap)
        << F.ModuleName << /*not new*/1 << ModMap->getName();
    return OutOfDate;
  }
}

if (Listener)
  Listener->ReadModuleMapFile(F.ModuleMapPath);
return Success;
4024}

4026/// Move the given method to the back of the global list of methods.
4027static void moveMethodToBackOfGlobalList(Sema &S, ObjCMethodDecl *Method) {
// Find the entry for this selector in the method pool.
Sema::GlobalMethodPool::iterator Known
  = S.MethodPool.find(Method->getSelector());
if (Known == S.MethodPool.end())
  return;

// Retrieve the appropriate method list.
ObjCMethodList &Start = Method->isInstanceMethod()? Known->second.first
                                                  : Known->second.second;
bool Found = false;
for (ObjCMethodList *List = &Start; List; List = List->getNext()) {
  if (!Found) {
    if (List->getMethod() == Method) {
      Found = true;
    } else {
      // Keep searching.
      continue;
    }
  }

  if (List->getNext())
    List->setMethod(List->getNext()->getMethod());
  else
    List->setMethod(Method);
}
4053}

4055void ASTReader::makeNamesVisible(const HiddenNames &Names, Module *Owner) {
assert(Owner->NameVisibility != Module::Hidden && "nothing to make visible?")((void)0);
for (Decl *D : Names) {
  bool wasHidden = !D->isUnconditionallyVisible();
  D->setVisibleDespiteOwningModule();

  if (wasHidden && SemaObj) {
    if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(D)) {
      moveMethodToBackOfGlobalList(*SemaObj, Method);
    }
  }
}
4067}

4069void ASTReader::makeModuleVisible(Module *Mod,
                                Module::NameVisibilityKind NameVisibility,
                                SourceLocation ImportLoc) {
llvm::SmallPtrSet<Module *, 4> Visited;
SmallVector<Module *, 4> Stack;
Stack.push_back(Mod);
while (!Stack.empty()) {
  Mod = Stack.pop_back_val();

  if (NameVisibility <= Mod->NameVisibility) {
    // This module already has this level of visibility (or greater), so
    // there is nothing more to do.
    continue;
  }

  if (Mod->isUnimportable()) {
    // Modules that aren't importable cannot be made visible.
    continue;
  }

  // Update the module's name visibility.
  Mod->NameVisibility = NameVisibility;

  // If we've already deserialized any names from this module,
  // mark them as visible.
  HiddenNamesMapType::iterator Hidden = HiddenNamesMap.find(Mod);
  if (Hidden != HiddenNamesMap.end()) {
    auto HiddenNames = std::move(*Hidden);
    HiddenNamesMap.erase(Hidden);
    makeNamesVisible(HiddenNames.second, HiddenNames.first);
    assert(HiddenNamesMap.find(Mod) == HiddenNamesMap.end() &&((void)0)
           "making names visible added hidden names")((void)0);
  }

  // Push any exported modules onto the stack to be marked as visible.
  SmallVector<Module *, 16> Exports;
  Mod->getExportedModules(Exports);
  for (SmallVectorImpl<Module *>::iterator
         I = Exports.begin(), E = Exports.end(); I != E; ++I) {
    Module *Exported = *I;
    if (Visited.insert(Exported).second)
      Stack.push_back(Exported);
  }
}
4113}

4115/// We've merged the definition \p MergedDef into the existing definition
4116/// \p Def. Ensure that \p Def is made visible whenever \p MergedDef is made
4117/// visible.
4118void ASTReader::mergeDefinitionVisibility(NamedDecl *Def,
                                        NamedDecl *MergedDef) {
if (!Def->isUnconditionallyVisible()) {
  // If MergedDef is visible or becomes visible, make the definition visible.
  if (MergedDef->isUnconditionallyVisible())
    Def->setVisibleDespiteOwningModule();
  else {
    getContext().mergeDefinitionIntoModule(
        Def, MergedDef->getImportedOwningModule(),
        /*NotifyListeners*/ false);
    PendingMergedDefinitionsToDeduplicate.insert(Def);
  }
}
4131}

4133bool ASTReader::loadGlobalIndex() {
if (GlobalIndex)
  return false;

if (TriedLoadingGlobalIndex || !UseGlobalIndex ||
    !PP.getLangOpts().Modules)
  return true;

// Try to load the global index.
TriedLoadingGlobalIndex = true;
StringRef ModuleCachePath
  = getPreprocessor().getHeaderSearchInfo().getModuleCachePath();
std::pair<GlobalModuleIndex *, llvm::Error> Result =
    GlobalModuleIndex::readIndex(ModuleCachePath);
if (llvm::Error Err = std::move(Result.second)) {
  assert(!Result.first)((void)0);
  consumeError(std::move(Err)); // FIXME this drops errors on the floor.
  return true;
}

GlobalIndex.reset(Result.first);
ModuleMgr.setGlobalIndex(GlobalIndex.get());
return false;
4156}

4158bool ASTReader::isGlobalIndexUnavailable() const {
return PP.getLangOpts().Modules && UseGlobalIndex &&
       !hasGlobalIndex() && TriedLoadingGlobalIndex;
4161}

4163static void updateModuleTimestamp(ModuleFile &MF) {
// Overwrite the timestamp file contents so that file's mtime changes.
std::string TimestampFilename = MF.getTimestampFilename();
std::error_code EC;
llvm::raw_fd_ostream OS(TimestampFilename, EC,
                        llvm::sys::fs::OF_TextWithCRLF);
if (EC)
  return;
OS << "Timestamp file\n";
OS.close();
OS.clear_error(); // Avoid triggering a fatal error.
4174}

4176/// Given a cursor at the start of an AST file, scan ahead and drop the
4177/// cursor into the start of the given block ID, returning false on success and
4178/// true on failure.
4179static bool SkipCursorToBlock(BitstreamCursor &Cursor, unsigned BlockID) {
while (true) {
  Expected<llvm::BitstreamEntry> MaybeEntry = Cursor.advance();
  if (!MaybeEntry) {
    // FIXME this drops errors on the floor.
    consumeError(MaybeEntry.takeError());
    return true;
  }
  llvm::BitstreamEntry Entry = MaybeEntry.get();

  switch (Entry.Kind) {
  case llvm::BitstreamEntry::Error:
  case llvm::BitstreamEntry::EndBlock:
    return true;

  case llvm::BitstreamEntry::Record:
    // Ignore top-level records.
    if (Expected<unsigned> Skipped = Cursor.skipRecord(Entry.ID))
      break;
    else {
      // FIXME this drops errors on the floor.
      consumeError(Skipped.takeError());
      return true;
    }

  case llvm::BitstreamEntry::SubBlock:
    if (Entry.ID == BlockID) {
      if (llvm::Error Err = Cursor.EnterSubBlock(BlockID)) {
        // FIXME this drops the error on the floor.
        consumeError(std::move(Err));
        return true;
      }
      // Found it!
      return false;
    }

    if (llvm::Error Err = Cursor.SkipBlock()) {
      // FIXME this drops the error on the floor.
      consumeError(std::move(Err));
      return true;
    }
  }
}
4222}

4224ASTReader::ASTReadResult ASTReader::ReadAST(StringRef FileName,
                                          ModuleKind Type,
                                          SourceLocation ImportLoc,
                                          unsigned ClientLoadCapabilities,
                                          SmallVectorImpl<ImportedSubmodule> *Imported) {
llvm::SaveAndRestore<SourceLocation>
  SetCurImportLocRAII(CurrentImportLoc, ImportLoc);
llvm::SaveAndRestore<Optional<ModuleKind>> SetCurModuleKindRAII(
    CurrentDeserializingModuleKind, Type);

// Defer any pending actions until we get to the end of reading the AST file.
Deserializing AnASTFile(this);

// Bump the generation number.
unsigned PreviousGeneration = 0;
if (ContextObj)
1
Assuming field 'ContextObj' is null→
2
←
Taking false branch→
  PreviousGeneration = incrementGeneration(*ContextObj);

unsigned NumModules = ModuleMgr.size();
auto removeModulesAndReturn = [&](ASTReadResult ReadResult) {
  assert(ReadResult && "expected to return error")((void)0);
  ModuleMgr.removeModules(ModuleMgr.begin() + NumModules,
                          PP.getLangOpts().Modules
                              ? &PP.getHeaderSearchInfo().getModuleMap()
                              : nullptr);

  // If we find that any modules are unusable, the global index is going
  // to be out-of-date. Just remove it.
  GlobalIndex.reset();
  ModuleMgr.setGlobalIndex(nullptr);
  return ReadResult;
};

SmallVector<ImportedModule, 4> Loaded;
switch (ASTReadResult ReadResult =
3
←
Control jumps to 'case Success:'  at line 4269→
            ReadASTCore(FileName, Type, ImportLoc,
                        /*ImportedBy=*/nullptr, Loaded, 0, 0,
                        ASTFileSignature(), ClientLoadCapabilities)) {
case Failure:
case Missing:
case OutOfDate:
case VersionMismatch:
case ConfigurationMismatch:
case HadErrors:
  return removeModulesAndReturn(ReadResult);
case Success:
  break;
4
←
 Execution continues on line 4277→
}

// Here comes stuff that we only do once the entire chain is loaded.

// Load the AST blocks of all of the modules that we loaded.  We can still
// hit errors parsing the ASTs at this point.
for (ImportedModule &M : Loaded) {
5
←
Assuming '__begin1' is equal to '__end1'→
  ModuleFile &F = *M.Mod;

  // Read the AST block.
  if (ASTReadResult Result = ReadASTBlock(F, ClientLoadCapabilities))
    return removeModulesAndReturn(Result);

  // The AST block should always have a definition for the main module.
  if (F.isModule() && !F.DidReadTopLevelSubmodule) {
    Error(diag::err_module_file_missing_top_level_submodule, F.FileName);
    return removeModulesAndReturn(Failure);
  }

  // Read the extension blocks.
  while (!SkipCursorToBlock(F.Stream, EXTENSION_BLOCK_ID)) {
    if (ASTReadResult Result = ReadExtensionBlock(F))
      return removeModulesAndReturn(Result);
  }

  // Once read, set the ModuleFile bit base offset and update the size in
  // bits of all files we've seen.
  F.GlobalBitOffset = TotalModulesSizeInBits;
  TotalModulesSizeInBits += F.SizeInBits;
  GlobalBitOffsetsMap.insert(std::make_pair(F.GlobalBitOffset, &F));
}

// Preload source locations and interesting indentifiers.
for (ImportedModule &M : Loaded) {
6
←
Assuming '__begin1' is equal to '__end1'→
  ModuleFile &F = *M.Mod;

  // Preload SLocEntries.
  for (unsigned I = 0, N = F.PreloadSLocEntries.size(); I != N; ++I) {
    int Index = int(F.PreloadSLocEntries[I] - 1) + F.SLocEntryBaseID;
    // Load it through the SourceManager and don't call ReadSLocEntry()
    // directly because the entry may have already been loaded in which case
    // calling ReadSLocEntry() directly would trigger an assertion in
    // SourceManager.
    SourceMgr.getLoadedSLocEntryByID(Index);
  }

  // Map the original source file ID into the ID space of the current
  // compilation.
  if (F.OriginalSourceFileID.isValid()) {
    F.OriginalSourceFileID = FileID::get(
        F.SLocEntryBaseID + F.OriginalSourceFileID.getOpaqueValue() - 1);
  }

  // Preload all the pending interesting identifiers by marking them out of
  // date.
  for (auto Offset : F.PreloadIdentifierOffsets) {
    const unsigned char *Data = F.IdentifierTableData + Offset;

    ASTIdentifierLookupTrait Trait(*this, F);
    auto KeyDataLen = Trait.ReadKeyDataLength(Data);
    auto Key = Trait.ReadKey(Data, KeyDataLen.first);
    auto &II = PP.getIdentifierTable().getOwn(Key);
    II.setOutOfDate(true);

    // Mark this identifier as being from an AST file so that we can track
    // whether we need to serialize it.
    markIdentifierFromAST(*this, II);

    // Associate the ID with the identifier so that the writer can reuse it.
    auto ID = Trait.ReadIdentifierID(Data + KeyDataLen.first);
    SetIdentifierInfo(ID, &II);
  }
}

// Setup the import locations and notify the module manager that we've
// committed to these module files.
for (ImportedModule &M : Loaded) {
7
←
Assuming '__begin1' is equal to '__end1'→
  ModuleFile &F = *M.Mod;

  ModuleMgr.moduleFileAccepted(&F);

  // Set the import location.
  F.DirectImportLoc = ImportLoc;
  // FIXME: We assume that locations from PCH / preamble do not need
  // any translation.
  if (!M.ImportedBy)
    F.ImportLoc = M.ImportLoc;
  else
    F.ImportLoc = TranslateSourceLocation(*M.ImportedBy, M.ImportLoc);
}

if (!PP.getLangOpts().CPlusPlus ||
8
←
Assuming field 'CPlusPlus' is not equal to 0→
    (Type != MK_ImplicitModule && Type != MK_ExplicitModule &&
9
←
Assuming 'Type' is equal to MK_ImplicitModule→
     Type != MK_PrebuiltModule)) {
  // Mark all of the identifiers in the identifier table as being out of date,
  // so that various accessors know to check the loaded modules when the
  // identifier is used.
  //
  // For C++ modules, we don't need information on many identifiers (just
  // those that provide macros or are poisoned), so we mark all of
  // the interesting ones via PreloadIdentifierOffsets.
  for (IdentifierTable::iterator Id = PP.getIdentifierTable().begin(),
                              IdEnd = PP.getIdentifierTable().end();
       Id != IdEnd; ++Id)
    Id->second->setOutOfDate(true);
}
// Mark selectors as out of date.
for (auto Sel : SelectorGeneration)
  SelectorOutOfDate[Sel.first] = true;

// Resolve any unresolved module exports.
for (unsigned I = 0, N = UnresolvedModuleRefs.size(); I != N; ++I) {
10
←
Assuming 'I' is equal to 'N'→
11
←
Loop condition is false. Execution continues on line 4409→
  UnresolvedModuleRef &Unresolved = UnresolvedModuleRefs[I];
  SubmoduleID GlobalID = getGlobalSubmoduleID(*Unresolved.File,Unresolved.ID);
  Module *ResolvedMod = getSubmodule(GlobalID);

  switch (Unresolved.Kind) {
  case UnresolvedModuleRef::Conflict:
    if (ResolvedMod) {
      Module::Conflict Conflict;
      Conflict.Other = ResolvedMod;
      Conflict.Message = Unresolved.String.str();
      Unresolved.Mod->Conflicts.push_back(Conflict);
    }
    continue;

  case UnresolvedModuleRef::Import:
    if (ResolvedMod)
      Unresolved.Mod->Imports.insert(ResolvedMod);
    continue;

  case UnresolvedModuleRef::Export:
    if (ResolvedMod || Unresolved.IsWildcard)
      Unresolved.Mod->Exports.push_back(
        Module::ExportDecl(ResolvedMod, Unresolved.IsWildcard));
    continue;
  }
}
UnresolvedModuleRefs.clear();

if (Imported)
12
←
Assuming 'Imported' is null→
13
←
Taking false branch→
  Imported->append(ImportedModules.begin(),
                   ImportedModules.end());

// FIXME: How do we load the 'use'd modules? They may not be submodules.
// Might be unnecessary as use declarations are only used to build the
// module itself.

if (ContextObj)
14
←
Assuming field 'ContextObj' is non-null→
15
←
Taking true branch→
  InitializeContext();
16
←
Calling 'ASTReader::InitializeContext'→

if (SemaObj)
  UpdateSema();

if (DeserializationListener)
  DeserializationListener->ReaderInitialized(this);

ModuleFile &PrimaryModule = ModuleMgr.getPrimaryModule();
if (PrimaryModule.OriginalSourceFileID.isValid()) {
  // If this AST file is a precompiled preamble, then set the
  // preamble file ID of the source manager to the file source file
  // from which the preamble was built.
  if (Type == MK_Preamble) {
    SourceMgr.setPreambleFileID(PrimaryModule.OriginalSourceFileID);
  } else if (Type == MK_MainFile) {
    SourceMgr.setMainFileID(PrimaryModule.OriginalSourceFileID);
  }
}

// For any Objective-C class definitions we have already loaded, make sure
// that we load any additional categories.
if (ContextObj) {
  for (unsigned I = 0, N = ObjCClassesLoaded.size(); I != N; ++I) {
    loadObjCCategories(ObjCClassesLoaded[I]->getGlobalID(),
                       ObjCClassesLoaded[I],
                       PreviousGeneration);
  }
}

if (PP.getHeaderSearchInfo()
        .getHeaderSearchOpts()
        .ModulesValidateOncePerBuildSession) {
  // Now we are certain that the module and all modules it depends on are
  // up to date.  Create or update timestamp files for modules that are
  // located in the module cache (not for PCH files that could be anywhere
  // in the filesystem).
  for (unsigned I = 0, N = Loaded.size(); I != N; ++I) {
    ImportedModule &M = Loaded[I];
    if (M.Mod->Kind == MK_ImplicitModule) {
      updateModuleTimestamp(*M.Mod);
    }
  }
}

return Success;
4466}

4468static ASTFileSignature readASTFileSignature(StringRef PCH);

4470/// Whether \p Stream doesn't start with the AST/PCH file magic number 'CPCH'.
4471static llvm::Error doesntStartWithASTFileMagic(BitstreamCursor &Stream) {
// FIXME checking magic headers is done in other places such as
// SerializedDiagnosticReader and GlobalModuleIndex, but error handling isn't
// always done the same. Unify it all with a helper.
if (!Stream.canSkipToPos(4))
  return llvm::createStringError(std::errc::illegal_byte_sequence,
                                 "file too small to contain AST file magic");
for (unsigned C : {'C', 'P', 'C', 'H'})
  if (Expected<llvm::SimpleBitstreamCursor::word_t> Res = Stream.Read(8)) {
    if (Res.get() != C)
      return llvm::createStringError(
          std::errc::illegal_byte_sequence,
          "file doesn't start with AST file magic");
  } else
    return Res.takeError();
return llvm::Error::success();
4487}

4489static unsigned moduleKindForDiagnostic(ModuleKind Kind) {
switch (Kind) {
case MK_PCH:
  return 0; // PCH
case MK_ImplicitModule:
case MK_ExplicitModule:
case MK_PrebuiltModule:
  return 1; // module
case MK_MainFile:
case MK_Preamble:
  return 2; // main source file
}
llvm_unreachable("unknown module kind")__builtin_unreachable();
4502}

4504ASTReader::ASTReadResult
4505ASTReader::ReadASTCore(StringRef FileName,
                     ModuleKind Type,
                     SourceLocation ImportLoc,
                     ModuleFile *ImportedBy,
                     SmallVectorImpl<ImportedModule> &Loaded,
                     off_t ExpectedSize, time_t ExpectedModTime,
                     ASTFileSignature ExpectedSignature,
                     unsigned ClientLoadCapabilities) {
ModuleFile *M;
std::string ErrorStr;
ModuleManager::AddModuleResult AddResult
  = ModuleMgr.addModule(FileName, Type, ImportLoc, ImportedBy,
                        getGeneration(), ExpectedSize, ExpectedModTime,
                        ExpectedSignature, readASTFileSignature,
                        M, ErrorStr);

switch (AddResult) {
case ModuleManager::AlreadyLoaded:
  Diag(diag::remark_module_import)
      << M->ModuleName << M->FileName << (ImportedBy ? true : false)
      << (ImportedBy ? StringRef(ImportedBy->ModuleName) : StringRef());
  return Success;

case ModuleManager::NewlyLoaded:
  // Load module file below.
  break;

case ModuleManager::Missing:
  // The module file was missing; if the client can handle that, return
  // it.
  if (ClientLoadCapabilities & ARR_Missing)
    return Missing;

  // Otherwise, return an error.
  Diag(diag::err_ast_file_not_found)
      << moduleKindForDiagnostic(Type) << FileName << !ErrorStr.empty()
      << ErrorStr;
  return Failure;

case ModuleManager::OutOfDate:
  // We couldn't load the module file because it is out-of-date. If the
  // client can handle out-of-date, return it.
  if (ClientLoadCapabilities & ARR_OutOfDate)
    return OutOfDate;

  // Otherwise, return an error.
  Diag(diag::err_ast_file_out_of_date)
      << moduleKindForDiagnostic(Type) << FileName << !ErrorStr.empty()
      << ErrorStr;
  return Failure;
}

assert(M && "Missing module file")((void)0);

bool ShouldFinalizePCM = false;
auto FinalizeOrDropPCM = llvm::make_scope_exit([&]() {
  auto &MC = getModuleManager().getModuleCache();
  if (ShouldFinalizePCM)
    MC.finalizePCM(FileName);
  else
    MC.tryToDropPCM(FileName);
});
ModuleFile &F = *M;
BitstreamCursor &Stream = F.Stream;
Stream = BitstreamCursor(PCHContainerRdr.ExtractPCH(*F.Buffer));
F.SizeInBits = F.Buffer->getBufferSize() * 8;

// Sniff for the signature.
if (llvm::Error Err = doesntStartWithASTFileMagic(Stream)) {
  Diag(diag::err_ast_file_invalid)
      << moduleKindForDiagnostic(Type) << FileName << std::move(Err);
  return Failure;
}

// This is used for compatibility with older PCH formats.
bool HaveReadControlBlock = false;
while (true) {
  Expected<llvm::BitstreamEntry> MaybeEntry = Stream.advance();
  if (!MaybeEntry) {
    Error(MaybeEntry.takeError());
    return Failure;
  }
  llvm::BitstreamEntry Entry = MaybeEntry.get();

  switch (Entry.Kind) {
  case llvm::BitstreamEntry::Error:
  case llvm::BitstreamEntry::Record:
  case llvm::BitstreamEntry::EndBlock:
    Error("invalid record at top-level of AST file");
    return Failure;

  case llvm::BitstreamEntry::SubBlock:
    break;
  }

  switch (Entry.ID) {
  case CONTROL_BLOCK_ID:
    HaveReadControlBlock = true;
    switch (ReadControlBlock(F, Loaded, ImportedBy, ClientLoadCapabilities)) {
    case Success:
      // Check that we didn't try to load a non-module AST file as a module.
      //
      // FIXME: Should we also perform the converse check? Loading a module as
      // a PCH file sort of works, but it's a bit wonky.
      if ((Type == MK_ImplicitModule || Type == MK_ExplicitModule ||
           Type == MK_PrebuiltModule) &&
          F.ModuleName.empty()) {
        auto Result = (Type == MK_ImplicitModule) ? OutOfDate : Failure;
        if (Result != OutOfDate ||
            (ClientLoadCapabilities & ARR_OutOfDate) == 0)
          Diag(diag::err_module_file_not_module) << FileName;
        return Result;
      }
      break;

    case Failure: return Failure;
    case Missing: return Missing;
    case OutOfDate: return OutOfDate;
    case VersionMismatch: return VersionMismatch;
    case ConfigurationMismatch: return ConfigurationMismatch;
    case HadErrors: return HadErrors;
    }
    break;

  case AST_BLOCK_ID:
    if (!HaveReadControlBlock) {
      if ((ClientLoadCapabilities & ARR_VersionMismatch) == 0)
        Diag(diag::err_pch_version_too_old);
      return VersionMismatch;
    }

    // Record that we've loaded this module.
    Loaded.push_back(ImportedModule(M, ImportedBy, ImportLoc));
    ShouldFinalizePCM = true;
    return Success;

  case UNHASHED_CONTROL_BLOCK_ID:
    // This block is handled using look-ahead during ReadControlBlock.  We
    // shouldn't get here!
    Error("malformed block record in AST file");
    return Failure;

  default:
    if (llvm::Error Err = Stream.SkipBlock()) {
      Error(std::move(Err));
      return Failure;
    }
    break;
  }
}

llvm_unreachable("unexpected break; expected return")__builtin_unreachable();
4657}

4659ASTReader::ASTReadResult
4660ASTReader::readUnhashedControlBlock(ModuleFile &F, bool WasImportedBy,
                                  unsigned ClientLoadCapabilities) {
const HeaderSearchOptions &HSOpts =
    PP.getHeaderSearchInfo().getHeaderSearchOpts();
bool AllowCompatibleConfigurationMismatch =
    F.Kind == MK_ExplicitModule || F.Kind == MK_PrebuiltModule;
bool DisableValidation = shouldDisableValidationForFile(F);

ASTReadResult Result = readUnhashedControlBlockImpl(
    &F, F.Data, ClientLoadCapabilities, AllowCompatibleConfigurationMismatch,
    Listener.get(),
    WasImportedBy ? false : HSOpts.ModulesValidateDiagnosticOptions);

// If F was directly imported by another module, it's implicitly validated by
// the importing module.
if (DisableValidation || WasImportedBy ||
    (AllowConfigurationMismatch && Result == ConfigurationMismatch))
  return Success;

if (Result == Failure) {
  Error("malformed block record in AST file");
  return Failure;
}

if (Result == OutOfDate && F.Kind == MK_ImplicitModule) {
  // If this module has already been finalized in the ModuleCache, we're stuck
  // with it; we can only load a single version of each module.
  //
  // This can happen when a module is imported in two contexts: in one, as a
  // user module; in another, as a system module (due to an import from
  // another module marked with the [system] flag).  It usually indicates a
  // bug in the module map: this module should also be marked with [system].
  //
  // If -Wno-system-headers (the default), and the first import is as a
  // system module, then validation will fail during the as-user import,
  // since -Werror flags won't have been validated.  However, it's reasonable
  // to treat this consistently as a system module.
  //
  // If -Wsystem-headers, the PCM on disk was built with
  // -Wno-system-headers, and the first import is as a user module, then
  // validation will fail during the as-system import since the PCM on disk
  // doesn't guarantee that -Werror was respected.  However, the -Werror
  // flags were checked during the initial as-user import.
  if (getModuleManager().getModuleCache().isPCMFinal(F.FileName)) {
    Diag(diag::warn_module_system_bit_conflict) << F.FileName;
    return Success;
  }
}

return Result;
4710}

4712ASTReader::ASTReadResult ASTReader::readUnhashedControlBlockImpl(
  ModuleFile *F, llvm::StringRef StreamData, unsigned ClientLoadCapabilities,
  bool AllowCompatibleConfigurationMismatch, ASTReaderListener *Listener,
  bool ValidateDiagnosticOptions) {
// Initialize a stream.
BitstreamCursor Stream(StreamData);

// Sniff for the signature.
if (llvm::Error Err = doesntStartWithASTFileMagic(Stream)) {
  // FIXME this drops the error on the floor.
  consumeError(std::move(Err));
  return Failure;
}

// Scan for the UNHASHED_CONTROL_BLOCK_ID block.
if (SkipCursorToBlock(Stream, UNHASHED_CONTROL_BLOCK_ID))
  return Failure;

// Read all of the records in the options block.
RecordData Record;
ASTReadResult Result = Success;
while (true) {
  Expected<llvm::BitstreamEntry> MaybeEntry = Stream.advance();
  if (!MaybeEntry) {
    // FIXME this drops the error on the floor.
    consumeError(MaybeEntry.takeError());
    return Failure;
  }
  llvm::BitstreamEntry Entry = MaybeEntry.get();

  switch (Entry.Kind) {
  case llvm::BitstreamEntry::Error:
  case llvm::BitstreamEntry::SubBlock:
    return Failure;

  case llvm::BitstreamEntry::EndBlock:
    return Result;

  case llvm::BitstreamEntry::Record:
    // The interesting case.
    break;
  }

  // Read and process a record.
  Record.clear();
  Expected<unsigned> MaybeRecordType = Stream.readRecord(Entry.ID, Record);
  if (!MaybeRecordType) {
    // FIXME this drops the error.
    return Failure;
  }
  switch ((UnhashedControlBlockRecordTypes)MaybeRecordType.get()) {
  case SIGNATURE:
    if (F)
      F->Signature = ASTFileSignature::create(Record.begin(), Record.end());
    break;
  case AST_BLOCK_HASH:
    if (F)
      F->ASTBlockHash =
          ASTFileSignature::create(Record.begin(), Record.end());
    break;
  case DIAGNOSTIC_OPTIONS: {
    bool Complain = (ClientLoadCapabilities & ARR_OutOfDate) == 0;
    if (Listener && ValidateDiagnosticOptions &&
        !AllowCompatibleConfigurationMismatch &&
        ParseDiagnosticOptions(Record, Complain, *Listener))
      Result = OutOfDate; // Don't return early.  Read the signature.
    break;
  }
  case DIAG_PRAGMA_MAPPINGS:
    if (!F)
      break;
    if (F->PragmaDiagMappings.empty())
      F->PragmaDiagMappings.swap(Record);
    else
      F->PragmaDiagMappings.insert(F->PragmaDiagMappings.end(),
                                   Record.begin(), Record.end());
    break;
  }
}
4791}

4793/// Parse a record and blob containing module file extension metadata.
4794static bool parseModuleFileExtensionMetadata(
            const SmallVectorImpl<uint64_t> &Record,
            StringRef Blob,
            ModuleFileExtensionMetadata &Metadata) {
if (Record.size() < 4) return true;

Metadata.MajorVersion = Record[0];
Metadata.MinorVersion = Record[1];

unsigned BlockNameLen = Record[2];
unsigned UserInfoLen = Record[3];

if (BlockNameLen + UserInfoLen > Blob.size()) return true;

Metadata.BlockName = std::string(Blob.data(), Blob.data() + BlockNameLen);
Metadata.UserInfo = std::string(Blob.data() + BlockNameLen,
                                Blob.data() + BlockNameLen + UserInfoLen);
return false;
4812}

4814ASTReader::ASTReadResult ASTReader::ReadExtensionBlock(ModuleFile &F) {
BitstreamCursor &Stream = F.Stream;

RecordData Record;
while (true) {
  Expected<llvm::BitstreamEntry> MaybeEntry = Stream.advance();
  if (!MaybeEntry) {
    Error(MaybeEntry.takeError());
    return Failure;
  }
  llvm::BitstreamEntry Entry = MaybeEntry.get();

  switch (Entry.Kind) {
  case llvm::BitstreamEntry::SubBlock:
    if (llvm::Error Err = Stream.SkipBlock()) {
      Error(std::move(Err));
      return Failure;
    }
    continue;

  case llvm::BitstreamEntry::EndBlock:
    return Success;

  case llvm::BitstreamEntry::Error:
    return HadErrors;

  case llvm::BitstreamEntry::Record:
    break;
  }

  Record.clear();
  StringRef Blob;
  Expected<unsigned> MaybeRecCode =
      Stream.readRecord(Entry.ID, Record, &Blob);
  if (!MaybeRecCode) {
    Error(MaybeRecCode.takeError());
    return Failure;
  }
  switch (MaybeRecCode.get()) {
  case EXTENSION_METADATA: {
    ModuleFileExtensionMetadata Metadata;
    if (parseModuleFileExtensionMetadata(Record, Blob, Metadata)) {
      Error("malformed EXTENSION_METADATA in AST file");
      return Failure;
    }

    // Find a module file extension with this block name.
    auto Known = ModuleFileExtensions.find(Metadata.BlockName);
    if (Known == ModuleFileExtensions.end()) break;

    // Form a reader.
    if (auto Reader = Known->second->createExtensionReader(Metadata, *this,
                                                           F, Stream)) {
      F.ExtensionReaders.push_back(std::move(Reader));
    }

    break;
  }
  }
}

return Success;
4876}

4878void ASTReader::InitializeContext() {
assert(ContextObj && "no context to initialize")((void)0);
ASTContext &Context = *ContextObj;

// If there's a listener, notify them that we "read" the translation unit.
if (DeserializationListener)
17
←
Assuming field 'DeserializationListener' is null→
18
←
Taking false branch→
  DeserializationListener->DeclRead(PREDEF_DECL_TRANSLATION_UNIT_ID,
                                    Context.getTranslationUnitDecl());

// FIXME: Find a better way to deal with collisions between these
// built-in types. Right now, we just ignore the problem.

// Load the special types.
if (SpecialTypes.size() >= NumSpecialTypeIDs) {
19
←
Assuming the condition is true→
20
←
Taking true branch→
  if (unsigned String = SpecialTypes[SPECIAL_TYPE_CF_CONSTANT_STRING]) {
21
←
Assuming 'String' is 0→
22
←
Taking false branch→
    if (!Context.CFConstantStringTypeDecl)
      Context.setCFConstantStringType(GetType(String));
  }

  if (unsigned File = SpecialTypes[SPECIAL_TYPE_FILE]) {
23
←
Assuming 'File' is 0→
24
←
Taking false branch→
    QualType FileType = GetType(File);
    if (FileType.isNull()) {
      Error("FILE type is NULL");
      return;
    }

    if (!Context.FILEDecl) {
      if (const TypedefType *Typedef = FileType->getAs<TypedefType>())
        Context.setFILEDecl(Typedef->getDecl());
      else {
        const TagType *Tag = FileType->getAs<TagType>();
        if (!Tag) {
          Error("Invalid FILE type in AST file");
          return;
        }
        Context.setFILEDecl(Tag->getDecl());
      }
    }
  }

  if (unsigned Jmp_buf = SpecialTypes[SPECIAL_TYPE_JMP_BUF]) {
25
←
Assuming 'Jmp_buf' is 0→
26
←
Taking false branch→
    QualType Jmp_bufType = GetType(Jmp_buf);
    if (Jmp_bufType.isNull()) {
      Error("jmp_buf type is NULL");
      return;
    }

    if (!Context.jmp_bufDecl) {
      if (const TypedefType *Typedef = Jmp_bufType->getAs<TypedefType>())
        Context.setjmp_bufDecl(Typedef->getDecl());
      else {
        const TagType *Tag = Jmp_bufType->getAs<TagType>();
        if (!Tag) {
          Error("Invalid jmp_buf type in AST file");
          return;
        }
        Context.setjmp_bufDecl(Tag->getDecl());
      }
    }
  }

  if (unsigned Sigjmp_buf = SpecialTypes[SPECIAL_TYPE_SIGJMP_BUF]) {
27
←
Assuming 'Sigjmp_buf' is not equal to 0→
28
←
Taking true branch→
    QualType Sigjmp_bufType = GetType(Sigjmp_buf);
    if (Sigjmp_bufType.isNull()) {
29
←
Calling 'QualType::isNull'→
35
←
Returning from 'QualType::isNull'→
36
←
Taking false branch→
      Error("sigjmp_buf type is NULL");
      return;
    }

    if (!Context.sigjmp_bufDecl) {
37
←
Assuming field 'sigjmp_bufDecl' is null→
38
←
Taking true branch→
      if (const TypedefType *Typedef39.1
'Typedef' is null
1
'Typedef' is null
1
'Typedef' is null
 = Sigjmp_bufType->getAs<TypedefType>())
39
←
Assuming the object is not a 'TypedefType'→
40
←
Taking false branch→
        Context.setsigjmp_bufDecl(Typedef->getDecl());
      else {
        const TagType *Tag = Sigjmp_bufType->getAs<TagType>();
41
←
Assuming the object is not a 'TagType'→
42
←
'Tag' initialized to a null pointer value→
        assert(Tag && "Invalid sigjmp_buf type in AST file")((void)0);
        Context.setsigjmp_bufDecl(Tag->getDecl());
43
←
Called C++ object pointer is null
      }
    }
  }

  if (unsigned ObjCIdRedef
        = SpecialTypes[SPECIAL_TYPE_OBJC_ID_REDEFINITION]) {
    if (Context.ObjCIdRedefinitionType.isNull())
      Context.ObjCIdRedefinitionType = GetType(ObjCIdRedef);
  }

  if (unsigned ObjCClassRedef
        = SpecialTypes[SPECIAL_TYPE_OBJC_CLASS_REDEFINITION]) {
    if (Context.ObjCClassRedefinitionType.isNull())
      Context.ObjCClassRedefinitionType = GetType(ObjCClassRedef);
  }

  if (unsigned ObjCSelRedef
        = SpecialTypes[SPECIAL_TYPE_OBJC_SEL_REDEFINITION]) {
    if (Context.ObjCSelRedefinitionType.isNull())
      Context.ObjCSelRedefinitionType = GetType(ObjCSelRedef);
  }

  if (unsigned Ucontext_t = SpecialTypes[SPECIAL_TYPE_UCONTEXT_T]) {
    QualType Ucontext_tType = GetType(Ucontext_t);
    if (Ucontext_tType.isNull()) {
      Error("ucontext_t type is NULL");
      return;
    }

    if (!Context.ucontext_tDecl) {
      if (const TypedefType *Typedef = Ucontext_tType->getAs<TypedefType>())
        Context.setucontext_tDecl(Typedef->getDecl());
      else {
        const TagType *Tag = Ucontext_tType->getAs<TagType>();
        assert(Tag && "Invalid ucontext_t type in AST file")((void)0);
        Context.setucontext_tDecl(Tag->getDecl());
      }
    }
  }
}

ReadPragmaDiagnosticMappings(Context.getDiagnostics());

// If there were any CUDA special declarations, deserialize them.
if (!CUDASpecialDeclRefs.empty()) {
  assert(CUDASpecialDeclRefs.size() == 1 && "More decl refs than expected!")((void)0);
  Context.setcudaConfigureCallDecl(
                         cast<FunctionDecl>(GetDecl(CUDASpecialDeclRefs[0])));
}

// Re-export any modules that were imported by a non-module AST file.
// FIXME: This does not make macro-only imports visible again.
for (auto &Import : ImportedModules) {
  if (Module *Imported = getSubmodule(Import.ID)) {
    makeModuleVisible(Imported, Module::AllVisible,
                      /*ImportLoc=*/Import.ImportLoc);
    if (Import.ImportLoc.isValid())
      PP.makeModuleVisible(Imported, Import.ImportLoc);
    // This updates visibility for Preprocessor only. For Sema, which can be
    // nullptr here, we do the same later, in UpdateSema().
  }
}
5015}

5017void ASTReader::finalizeForWriting() {
// Nothing to do for now.
5019}

5021/// Reads and return the signature record from \p PCH's control block, or
5022/// else returns 0.
5023static ASTFileSignature readASTFileSignature(StringRef PCH) {
BitstreamCursor Stream(PCH);
if (llvm::Error Err = doesntStartWithASTFileMagic(Stream)) {
  // FIXME this drops the error on the floor.
  consumeError(std::move(Err));
  return ASTFileSignature();
}

// Scan for the UNHASHED_CONTROL_BLOCK_ID block.
if (SkipCursorToBlock(Stream, UNHASHED_CONTROL_BLOCK_ID))
  return ASTFileSignature();

// Scan for SIGNATURE inside the diagnostic options block.
ASTReader::RecordData Record;
while (true) {
  Expected<llvm::BitstreamEntry> MaybeEntry =
      Stream.advanceSkippingSubblocks();
  if (!MaybeEntry) {
    // FIXME this drops the error on the floor.
    consumeError(MaybeEntry.takeError());
    return ASTFileSignature();
  }
  llvm::BitstreamEntry Entry = MaybeEntry.get();

  if (Entry.Kind != llvm::BitstreamEntry::Record)
    return ASTFileSignature();

  Record.clear();
  StringRef Blob;
  Expected<unsigned> MaybeRecord = Stream.readRecord(Entry.ID, Record, &Blob);
  if (!MaybeRecord) {
    // FIXME this drops the error on the floor.
    consumeError(MaybeRecord.takeError());
    return ASTFileSignature();
  }
  if (SIGNATURE == MaybeRecord.get())
    return ASTFileSignature::create(Record.begin(),
                                    Record.begin() + ASTFileSignature::size);
}
5062}

5064/// Retrieve the name of the original source file name
5065/// directly from the AST file, without actually loading the AST
5066/// file.
5067std::string ASTReader::getOriginalSourceFile(
  const std::string &ASTFileName, FileManager &FileMgr,
  const PCHContainerReader &PCHContainerRdr, DiagnosticsEngine &Diags) {
// Open the AST file.
auto Buffer = FileMgr.getBufferForFile(ASTFileName);
if (!Buffer) {
  Diags.Report(diag::err_fe_unable_to_read_pch_file)
      << ASTFileName << Buffer.getError().message();
  return std::string();
}

// Initialize the stream
BitstreamCursor Stream(PCHContainerRdr.ExtractPCH(**Buffer));

// Sniff for the signature.
if (llvm::Error Err = doesntStartWithASTFileMagic(Stream)) {
  Diags.Report(diag::err_fe_not_a_pch_file) << ASTFileName << std::move(Err);
  return std::string();
}

// Scan for the CONTROL_BLOCK_ID block.
if (SkipCursorToBlock(Stream, CONTROL_BLOCK_ID)) {
  Diags.Report(diag::err_fe_pch_malformed_block) << ASTFileName;
  return std::string();
}

// Scan for ORIGINAL_FILE inside the control block.
RecordData Record;
while (true) {
  Expected<llvm::BitstreamEntry> MaybeEntry =
      Stream.advanceSkippingSubblocks();
  if (!MaybeEntry) {
    // FIXME this drops errors on the floor.
    consumeError(MaybeEntry.takeError());
    return std::string();
  }
  llvm::BitstreamEntry Entry = MaybeEntry.get();

  if (Entry.Kind == llvm::BitstreamEntry::EndBlock)
    return std::string();

  if (Entry.Kind != llvm::BitstreamEntry::Record) {
    Diags.Report(diag::err_fe_pch_malformed_block) << ASTFileName;
    return std::string();
  }

  Record.clear();
  StringRef Blob;
  Expected<unsigned> MaybeRecord = Stream.readRecord(Entry.ID, Record, &Blob);
  if (!MaybeRecord) {
    // FIXME this drops the errors on the floor.
    consumeError(MaybeRecord.takeError());
    return std::string();
  }
  if (ORIGINAL_FILE == MaybeRecord.get())
    return Blob.str();
}
5124}

5126namespace {

class SimplePCHValidator : public ASTReaderListener {
  const LangOptions &ExistingLangOpts;
  const TargetOptions &ExistingTargetOpts;
  const PreprocessorOptions &ExistingPPOpts;
  std::string ExistingModuleCachePath;
  FileManager &FileMgr;

public:
  SimplePCHValidator(const LangOptions &ExistingLangOpts,
                     const TargetOptions &ExistingTargetOpts,
                     const PreprocessorOptions &ExistingPPOpts,
                     StringRef ExistingModuleCachePath, FileManager &FileMgr)
      : ExistingLangOpts(ExistingLangOpts),
        ExistingTargetOpts(ExistingTargetOpts),
        ExistingPPOpts(ExistingPPOpts),
        ExistingModuleCachePath(ExistingModuleCachePath), FileMgr(FileMgr) {}

  bool ReadLanguageOptions(const LangOptions &LangOpts, bool Complain,
                           bool AllowCompatibleDifferences) override {
    return checkLanguageOptions(ExistingLangOpts, LangOpts, nullptr,
                                AllowCompatibleDifferences);
  }

  bool ReadTargetOptions(const TargetOptions &TargetOpts, bool Complain,
                         bool AllowCompatibleDifferences) override {
    return checkTargetOptions(ExistingTargetOpts, TargetOpts, nullptr,
                              AllowCompatibleDifferences);
  }

  bool ReadHeaderSearchOptions(const HeaderSearchOptions &HSOpts,
                               StringRef SpecificModuleCachePath,
                               bool Complain) override {
    return checkHeaderSearchOptions(HSOpts, SpecificModuleCachePath,
                                    ExistingModuleCachePath, nullptr,
                                    ExistingLangOpts, ExistingPPOpts);
  }

  bool ReadPreprocessorOptions(const PreprocessorOptions &PPOpts,
                               bool Complain,
                               std::string &SuggestedPredefines) override {
    return checkPreprocessorOptions(ExistingPPOpts, PPOpts, nullptr, FileMgr,
                                    SuggestedPredefines, ExistingLangOpts);
  }
};

5173} // namespace

5175bool ASTReader::readASTFileControlBlock(
  StringRef Filename, FileManager &FileMgr,
  const PCHContainerReader &PCHContainerRdr,
  bool FindModuleFileExtensions,
  ASTReaderListener &Listener, bool ValidateDiagnosticOptions) {
// Open the AST file.
// FIXME: This allows use of the VFS; we do not allow use of the
// VFS when actually loading a module.
auto Buffer = FileMgr.getBufferForFile(Filename);
if (!Buffer) {
  return true;
}

// Initialize the stream
StringRef Bytes = PCHContainerRdr.ExtractPCH(**Buffer);
BitstreamCursor Stream(Bytes);

// Sniff for the signature.
if (llvm::Error Err = doesntStartWithASTFileMagic(Stream)) {
  consumeError(std::move(Err)); // FIXME this drops errors on the floor.
  return true;
}

// Scan for the CONTROL_BLOCK_ID block.
if (SkipCursorToBlock(Stream, CONTROL_BLOCK_ID))
  return true;

bool NeedsInputFiles = Listener.needsInputFileVisitation();
bool NeedsSystemInputFiles = Listener.needsSystemInputFileVisitation();
bool NeedsImports = Listener.needsImportVisitation();
BitstreamCursor InputFilesCursor;

RecordData Record;
std::string ModuleDir;
bool DoneWithControlBlock = false;
while (!DoneWithControlBlock) {
  Expected<llvm::BitstreamEntry> MaybeEntry = Stream.advance();
  if (!MaybeEntry) {
    // FIXME this drops the error on the floor.
    consumeError(MaybeEntry.takeError());
    return true;
  }
  llvm::BitstreamEntry Entry = MaybeEntry.get();

  switch (Entry.Kind) {
  case llvm::BitstreamEntry::SubBlock: {
    switch (Entry.ID) {
    case OPTIONS_BLOCK_ID: {
      std::string IgnoredSuggestedPredefines;
      if (ReadOptionsBlock(Stream, ARR_ConfigurationMismatch | ARR_OutOfDate,
                           /*AllowCompatibleConfigurationMismatch*/ false,
                           Listener, IgnoredSuggestedPredefines) != Success)
        return true;
      break;
    }

    case INPUT_FILES_BLOCK_ID:
      InputFilesCursor = Stream;
      if (llvm::Error Err = Stream.SkipBlock()) {
        // FIXME this drops the error on the floor.
        consumeError(std::move(Err));
        return true;
      }
      if (NeedsInputFiles &&
          ReadBlockAbbrevs(InputFilesCursor, INPUT_FILES_BLOCK_ID))
        return true;
      break;

    default:
      if (llvm::Error Err = Stream.SkipBlock()) {
        // FIXME this drops the error on the floor.
        consumeError(std::move(Err));
        return true;
      }
      break;
    }

    continue;
  }

  case llvm::BitstreamEntry::EndBlock:
    DoneWithControlBlock = true;
    break;

  case llvm::BitstreamEntry::Error:
    return true;

  case llvm::BitstreamEntry::Record:
    break;
  }

  if (DoneWithControlBlock) break;

  Record.clear();
  StringRef Blob;
  Expected<unsigned> MaybeRecCode =
      Stream.readRecord(Entry.ID, Record, &Blob);
  if (!MaybeRecCode) {
    // FIXME this drops the error.
    return Failure;
  }
  switch ((ControlRecordTypes)MaybeRecCode.get()) {
  case METADATA:
    if (Record[0] != VERSION_MAJOR)
      return true;
    if (Listener.ReadFullVersionInformation(Blob))
      return true;
    break;
  case MODULE_NAME:
    Listener.ReadModuleName(Blob);
    break;
  case MODULE_DIRECTORY:
    ModuleDir = std::string(Blob);
    break;
  case MODULE_MAP_FILE: {
    unsigned Idx = 0;
    auto Path = ReadString(Record, Idx);
    ResolveImportedPath(Path, ModuleDir);
    Listener.ReadModuleMapFile(Path);
    break;
  }
  case INPUT_FILE_OFFSETS: {
    if (!NeedsInputFiles)
      break;

    unsigned NumInputFiles = Record[0];
    unsigned NumUserFiles = Record[1];
    const llvm::support::unaligned_uint64_t *InputFileOffs =
        (const llvm::support::unaligned_uint64_t *)Blob.data();
    for (unsigned I = 0; I != NumInputFiles; ++I) {
      // Go find this input file.
      bool isSystemFile = I >= NumUserFiles;

      if (isSystemFile && !NeedsSystemInputFiles)
        break; // the rest are system input files

      BitstreamCursor &Cursor = InputFilesCursor;
      SavedStreamPosition SavedPosition(Cursor);
      if (llvm::Error Err = Cursor.JumpToBit(InputFileOffs[I])) {
        // FIXME this drops errors on the floor.
        consumeError(std::move(Err));
      }

      Expected<unsigned> MaybeCode = Cursor.ReadCode();
      if (!MaybeCode) {
        // FIXME this drops errors on the floor.
        consumeError(MaybeCode.takeError());
      }
      unsigned Code = MaybeCode.get();

      RecordData Record;
      StringRef Blob;
      bool shouldContinue = false;
      Expected<unsigned> MaybeRecordType =
          Cursor.readRecord(Code, Record, &Blob);
      if (!MaybeRecordType) {
        // FIXME this drops errors on the floor.
        consumeError(MaybeRecordType.takeError());
      }
      switch ((InputFileRecordTypes)MaybeRecordType.get()) {
      case INPUT_FILE_HASH:
        break;
      case INPUT_FILE:
        bool Overridden = static_cast<bool>(Record[3]);
        std::string Filename = std::string(Blob);
        ResolveImportedPath(Filename, ModuleDir);
        shouldContinue = Listener.visitInputFile(
            Filename, isSystemFile, Overridden, /*IsExplicitModule*/false);
        break;
      }
      if (!shouldContinue)
        break;
    }
    break;
  }

  case IMPORTS: {
    if (!NeedsImports)
      break;

    unsigned Idx = 0, N = Record.size();
    while (Idx < N) {
      // Read information about the AST file.
      Idx +=
          1 + 1 + 1 + 1 +
          ASTFileSignature::size; // Kind, ImportLoc, Size, ModTime, Signature
      std::string ModuleName = ReadString(Record, Idx);
      std::string Filename = ReadString(Record, Idx);
      ResolveImportedPath(Filename, ModuleDir);
      Listener.visitImport(ModuleName, Filename);
    }
    break;
  }

  default:
    // No other validation to perform.
    break;
  }
}

// Look for module file extension blocks, if requested.
if (FindModuleFileExtensions) {
  BitstreamCursor SavedStream = Stream;
  while (!SkipCursorToBlock(Stream, EXTENSION_BLOCK_ID)) {
    bool DoneWithExtensionBlock = false;
    while (!DoneWithExtensionBlock) {
      Expected<llvm::BitstreamEntry> MaybeEntry = Stream.advance();
      if (!MaybeEntry) {
        // FIXME this drops the error.
        return true;
      }
      llvm::BitstreamEntry Entry = MaybeEntry.get();

      switch (Entry.Kind) {
      case llvm::BitstreamEntry::SubBlock:
        if (llvm::Error Err = Stream.SkipBlock()) {
          // FIXME this drops the error on the floor.
          consumeError(std::move(Err));
          return true;
        }
        continue;

      case llvm::BitstreamEntry::EndBlock:
        DoneWithExtensionBlock = true;
        continue;

      case llvm::BitstreamEntry::Error:
        return true;

      case llvm::BitstreamEntry::Record:
        break;
      }

     Record.clear();
     StringRef Blob;
     Expected<unsigned> MaybeRecCode =
         Stream.readRecord(Entry.ID, Record, &Blob);
     if (!MaybeRecCode) {
       // FIXME this drops the error.
       return true;
     }
     switch (MaybeRecCode.get()) {
     case EXTENSION_METADATA: {
       ModuleFileExtensionMetadata Metadata;
       if (parseModuleFileExtensionMetadata(Record, Blob, Metadata))
         return true;

       Listener.readModuleFileExtension(Metadata);
       break;
     }
     }
    }
  }
  Stream = SavedStream;
}

// Scan for the UNHASHED_CONTROL_BLOCK_ID block.
if (readUnhashedControlBlockImpl(
        nullptr, Bytes, ARR_ConfigurationMismatch | ARR_OutOfDate,
        /*AllowCompatibleConfigurationMismatch*/ false, &Listener,
        ValidateDiagnosticOptions) != Success)
  return true;

return false;
5439}

5441bool ASTReader::isAcceptableASTFile(StringRef Filename, FileManager &FileMgr,
                                  const PCHContainerReader &PCHContainerRdr,
                                  const LangOptions &LangOpts,
                                  const TargetOptions &TargetOpts,
                                  const PreprocessorOptions &PPOpts,
                                  StringRef ExistingModuleCachePath) {
SimplePCHValidator validator(LangOpts, TargetOpts, PPOpts,
                             ExistingModuleCachePath, FileMgr);
return !readASTFileControlBlock(Filename, FileMgr, PCHContainerRdr,
                                /*FindModuleFileExtensions=*/false,
                                validator,
                                /*ValidateDiagnosticOptions=*/true);
5453}

5455ASTReader::ASTReadResult
5456ASTReader::ReadSubmoduleBlock(ModuleFile &F, unsigned ClientLoadCapabilities) {
// Enter the submodule block.
if (llvm::Error Err = F.Stream.EnterSubBlock(SUBMODULE_BLOCK_ID)) {
  Error(std::move(Err));
  return Failure;
}

ModuleMap &ModMap = PP.getHeaderSearchInfo().getModuleMap();
bool First = true;
Module *CurrentModule = nullptr;
RecordData Record;
while (true) {
  Expected<llvm::BitstreamEntry> MaybeEntry =
      F.Stream.advanceSkippingSubblocks();
  if (!MaybeEntry) {
    Error(MaybeEntry.takeError());
    return Failure;
  }
  llvm::BitstreamEntry Entry = MaybeEntry.get();

  switch (Entry.Kind) {
  case llvm::BitstreamEntry::SubBlock: // Handled for us already.
  case llvm::BitstreamEntry::Error:
    Error("malformed block record in AST file");
    return Failure;
  case llvm::BitstreamEntry::EndBlock:
    return Success;
  case llvm::BitstreamEntry::Record:
    // The interesting case.
    break;
  }

  // Read a record.
  StringRef Blob;
  Record.clear();
  Expected<unsigned> MaybeKind = F.Stream.readRecord(Entry.ID, Record, &Blob);
  if (!MaybeKind) {
    Error(MaybeKind.takeError());
    return Failure;
  }
  unsigned Kind = MaybeKind.get();

  if ((Kind == SUBMODULE_METADATA) != First) {
    Error("submodule metadata record should be at beginning of block");
    return Failure;
  }
  First = false;

  // Submodule information is only valid if we have a current module.
  // FIXME: Should we error on these cases?
  if (!CurrentModule && Kind != SUBMODULE_METADATA &&
      Kind != SUBMODULE_DEFINITION)
    continue;

  switch (Kind) {
  default:  // Default behavior: ignore.
    break;

  case SUBMODULE_DEFINITION: {
    if (Record.size() < 12) {
      Error("malformed module definition");
      return Failure;
    }

    StringRef Name = Blob;
    unsigned Idx = 0;
    SubmoduleID GlobalID = getGlobalSubmoduleID(F, Record[Idx++]);
    SubmoduleID Parent = getGlobalSubmoduleID(F, Record[Idx++]);
    Module::ModuleKind Kind = (Module::ModuleKind)Record[Idx++];
    bool IsFramework = Record[Idx++];
    bool IsExplicit = Record[Idx++];
    bool IsSystem = Record[Idx++];
    bool IsExternC = Record[Idx++];
    bool InferSubmodules = Record[Idx++];
    bool InferExplicitSubmodules = Record[Idx++];
    bool InferExportWildcard = Record[Idx++];
    bool ConfigMacrosExhaustive = Record[Idx++];
    bool ModuleMapIsPrivate = Record[Idx++];

    Module *ParentModule = nullptr;
    if (Parent)
      ParentModule = getSubmodule(Parent);

    // Retrieve this (sub)module from the module map, creating it if
    // necessary.
    CurrentModule =
        ModMap.findOrCreateModule(Name, ParentModule, IsFramework, IsExplicit)
            .first;

    // FIXME: set the definition loc for CurrentModule, or call
    // ModMap.setInferredModuleAllowedBy()

    SubmoduleID GlobalIndex = GlobalID - NUM_PREDEF_SUBMODULE_IDS;
    if (GlobalIndex >= SubmodulesLoaded.size() ||
        SubmodulesLoaded[GlobalIndex]) {
      Error("too many submodules");
      return Failure;
    }

    if (!ParentModule) {
      if (const FileEntry *CurFile = CurrentModule->getASTFile()) {
        // Don't emit module relocation error if we have -fno-validate-pch
        if (!bool(PP.getPreprocessorOpts().DisablePCHOrModuleValidation &
                  DisableValidationForModuleKind::Module) &&
            CurFile != F.File) {
          Error(diag::err_module_file_conflict,
                CurrentModule->getTopLevelModuleName(), CurFile->getName(),
                F.File->getName());
          return Failure;
        }
      }

      F.DidReadTopLevelSubmodule = true;
      CurrentModule->setASTFile(F.File);
      CurrentModule->PresumedModuleMapFile = F.ModuleMapPath;
    }

    CurrentModule->Kind = Kind;
    CurrentModule->Signature = F.Signature;
    CurrentModule->IsFromModuleFile = true;
    CurrentModule->IsSystem = IsSystem || CurrentModule->IsSystem;
    CurrentModule->IsExternC = IsExternC;
    CurrentModule->InferSubmodules = InferSubmodules;
    CurrentModule->InferExplicitSubmodules = InferExplicitSubmodules;
    CurrentModule->InferExportWildcard = InferExportWildcard;
    CurrentModule->ConfigMacrosExhaustive = ConfigMacrosExhaustive;
    CurrentModule->ModuleMapIsPrivate = ModuleMapIsPrivate;
    if (DeserializationListener)
      DeserializationListener->ModuleRead(GlobalID, CurrentModule);

    SubmodulesLoaded[GlobalIndex] = CurrentModule;

    // Clear out data that will be replaced by what is in the module file.
    CurrentModule->LinkLibraries.clear();
    CurrentModule->ConfigMacros.clear();
    CurrentModule->UnresolvedConflicts.clear();
    CurrentModule->Conflicts.clear();

    // The module is available unless it's missing a requirement; relevant
    // requirements will be (re-)added by SUBMODULE_REQUIRES records.
    // Missing headers that were present when the module was built do not
    // make it unavailable -- if we got this far, this must be an explicitly
    // imported module file.
    CurrentModule->Requirements.clear();
    CurrentModule->MissingHeaders.clear();
    CurrentModule->IsUnimportable =
        ParentModule && ParentModule->IsUnimportable;
    CurrentModule->IsAvailable = !CurrentModule->IsUnimportable;
    break;
  }

  case SUBMODULE_UMBRELLA_HEADER: {
    std::string Filename = std::string(Blob);
    ResolveImportedPath(F, Filename);
    if (auto Umbrella = PP.getFileManager().getFile(Filename)) {
      if (!CurrentModule->getUmbrellaHeader())
        // FIXME: NameAsWritten
        ModMap.setUmbrellaHeader(CurrentModule, *Umbrella, Blob, "");
      else if (CurrentModule->getUmbrellaHeader().Entry != *Umbrella) {
        if ((ClientLoadCapabilities & ARR_OutOfDate) == 0)
          Error("mismatched umbrella headers in submodule");
        return OutOfDate;
      }
    }
    break;
  }

  case SUBMODULE_HEADER:
  case SUBMODULE_EXCLUDED_HEADER:
  case SUBMODULE_PRIVATE_HEADER:
    // We lazily associate headers with their modules via the HeaderInfo table.
    // FIXME: Re-evaluate this section; maybe only store InputFile IDs instead
    // of complete filenames or remove it entirely.
    break;

  case SUBMODULE_TEXTUAL_HEADER:
  case SUBMODULE_PRIVATE_TEXTUAL_HEADER:
    // FIXME: Textual headers are not marked in the HeaderInfo table. Load
    // them here.
    break;

  case SUBMODULE_TOPHEADER:
    CurrentModule->addTopHeaderFilename(Blob);
    break;

  case SUBMODULE_UMBRELLA_DIR: {
    std::string Dirname = std::string(Blob);
    ResolveImportedPath(F, Dirname);
    if (auto Umbrella = PP.getFileManager().getDirectory(Dirname)) {
      if (!CurrentModule->getUmbrellaDir())
        // FIXME: NameAsWritten
        ModMap.setUmbrellaDir(CurrentModule, *Umbrella, Blob, "");
      else if (CurrentModule->getUmbrellaDir().Entry != *Umbrella) {
        if ((ClientLoadCapabilities & ARR_OutOfDate) == 0)
          Error("mismatched umbrella directories in submodule");
        return OutOfDate;
      }
    }
    break;
  }

  case SUBMODULE_METADATA: {
    F.BaseSubmoduleID = getTotalNumSubmodules();
    F.LocalNumSubmodules = Record[0];
    unsigned LocalBaseSubmoduleID = Record[1];
    if (F.LocalNumSubmodules > 0) {
      // Introduce the global -> local mapping for submodules within this
      // module.
      GlobalSubmoduleMap.insert(std::make_pair(getTotalNumSubmodules()+1,&F));

      // Introduce the local -> global mapping for submodules within this
      // module.
      F.SubmoduleRemap.insertOrReplace(
        std::make_pair(LocalBaseSubmoduleID,
                       F.BaseSubmoduleID - LocalBaseSubmoduleID));

      SubmodulesLoaded.resize(SubmodulesLoaded.size() + F.LocalNumSubmodules);
    }
    break;
  }

  case SUBMODULE_IMPORTS:
    for (unsigned Idx = 0; Idx != Record.size(); ++Idx) {
      UnresolvedModuleRef Unresolved;
      Unresolved.File = &F;
      Unresolved.Mod = CurrentModule;
      Unresolved.ID = Record[Idx];
      Unresolved.Kind = UnresolvedModuleRef::Import;
      Unresolved.IsWildcard = false;
      UnresolvedModuleRefs.push_back(Unresolved);
    }
    break;

  case SUBMODULE_EXPORTS:
    for (unsigned Idx = 0; Idx + 1 < Record.size(); Idx += 2) {
      UnresolvedModuleRef Unresolved;
      Unresolved.File = &F;
      Unresolved.Mod = CurrentModule;
      Unresolved.ID = Record[Idx];
      Unresolved.Kind = UnresolvedModuleRef::Export;
      Unresolved.IsWildcard = Record[Idx + 1];
      UnresolvedModuleRefs.push_back(Unresolved);
    }

    // Once we've loaded the set of exports, there's no reason to keep
    // the parsed, unresolved exports around.
    CurrentModule->UnresolvedExports.clear();
    break;

  case SUBMODULE_REQUIRES:
    CurrentModule->addRequirement(Blob, Record[0], PP.getLangOpts(),
                                  PP.getTargetInfo());
    break;

  case SUBMODULE_LINK_LIBRARY:
    ModMap.resolveLinkAsDependencies(CurrentModule);
    CurrentModule->LinkLibraries.push_back(
        Module::LinkLibrary(std::string(Blob), Record[0]));
    break;

  case SUBMODULE_CONFIG_MACRO:
    CurrentModule->ConfigMacros.push_back(Blob.str());
    break;

  case SUBMODULE_CONFLICT: {
    UnresolvedModuleRef Unresolved;
    Unresolved.File = &F;
    Unresolved.Mod = CurrentModule;
    Unresolved.ID = Record[0];
    Unresolved.Kind = UnresolvedModuleRef::Conflict;
    Unresolved.IsWildcard = false;
    Unresolved.String = Blob;
    UnresolvedModuleRefs.push_back(Unresolved);
    break;
  }

  case SUBMODULE_INITIALIZERS: {
    if (!ContextObj)
      break;
    SmallVector<uint32_t, 16> Inits;
    for (auto &ID : Record)
      Inits.push_back(getGlobalDeclID(F, ID));
    ContextObj->addLazyModuleInitializers(CurrentModule, Inits);
    break;
  }

  case SUBMODULE_EXPORT_AS:
    CurrentModule->ExportAsModule = Blob.str();
    ModMap.addLinkAsDependency(CurrentModule);
    break;
  }
}
5748}

5750/// Parse the record that corresponds to a LangOptions data
5751/// structure.
5752///
5753/// This routine parses the language options from the AST file and then gives
5754/// them to the AST listener if one is set.
5755///
5756/// \returns true if the listener deems the file unacceptable, false otherwise.
5757bool ASTReader::ParseLanguageOptions(const RecordData &Record,
                                   bool Complain,
                                   ASTReaderListener &Listener,
                                   bool AllowCompatibleDifferences) {
LangOptions LangOpts;
unsigned Idx = 0;
5763#define LANGOPT(Name, Bits, Default, Description) \
LangOpts.Name = Record[Idx++];
5765#define ENUM_LANGOPT(Name, Type, Bits, Default, Description) \
LangOpts.set##Name(static_cast<LangOptions::Type>(Record[Idx++]));
5767#include "clang/Basic/LangOptions.def"
5768#define SANITIZER(NAME, ID)                                                    \
LangOpts.Sanitize.set(SanitizerKind::ID, Record[Idx++]);
5770#include "clang/Basic/Sanitizers.def"

for (unsigned N = Record[Idx++]; N; --N)
  LangOpts.ModuleFeatures.push_back(ReadString(Record, Idx));

ObjCRuntime::Kind runtimeKind = (ObjCRuntime::Kind) Record[Idx++];
VersionTuple runtimeVersion = ReadVersionTuple(Record, Idx);
LangOpts.ObjCRuntime = ObjCRuntime(runtimeKind, runtimeVersion);

LangOpts.CurrentModule = ReadString(Record, Idx);

// Comment options.
for (unsigned N = Record[Idx++]; N; --N) {
  LangOpts.CommentOpts.BlockCommandNames.push_back(
    ReadString(Record, Idx));
}
LangOpts.CommentOpts.ParseAllComments = Record[Idx++];

// OpenMP offloading options.
for (unsigned N = Record[Idx++]; N; --N) {
  LangOpts.OMPTargetTriples.push_back(llvm::Triple(ReadString(Record, Idx)));
}

LangOpts.OMPHostIRFile = ReadString(Record, Idx);

return Listener.ReadLanguageOptions(LangOpts, Complain,
                                    AllowCompatibleDifferences);
5797}

5799bool ASTReader::ParseTargetOptions(const RecordData &Record, bool Complain,
                                 ASTReaderListener &Listener,
                                 bool AllowCompatibleDifferences) {
unsigned Idx = 0;
TargetOptions TargetOpts;
TargetOpts.Triple = ReadString(Record, Idx);
TargetOpts.CPU = ReadString(Record, Idx);
TargetOpts.TuneCPU = ReadString(Record, Idx);
TargetOpts.ABI = ReadString(Record, Idx);
for (unsigned N = Record[Idx++]; N; --N) {
  TargetOpts.FeaturesAsWritten.push_back(ReadString(Record, Idx));
}
for (unsigned N = Record[Idx++]; N; --N) {
  TargetOpts.Features.push_back(ReadString(Record, Idx));
}

return Listener.ReadTargetOptions(TargetOpts, Complain,
                                  AllowCompatibleDifferences);
5817}

5819bool ASTReader::ParseDiagnosticOptions(const RecordData &Record, bool Complain,
                                     ASTReaderListener &Listener) {
IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts(new DiagnosticOptions);
unsigned Idx = 0;
5823#define DIAGOPT(Name, Bits, Default) DiagOpts->Name = Record[Idx++];
5824#define ENUM_DIAGOPT(Name, Type, Bits, Default) \
DiagOpts->set##Name(static_cast<Type>(Record[Idx++]));
5826#include "clang/Basic/DiagnosticOptions.def"

for (unsigned N = Record[Idx++]; N; --N)
  DiagOpts->Warnings.push_back(ReadString(Record, Idx));
for (unsigned N = Record[Idx++]; N; --N)
  DiagOpts->Remarks.push_back(ReadString(Record, Idx));

return Listener.ReadDiagnosticOptions(DiagOpts, Complain);
5834}

5836bool ASTReader::ParseFileSystemOptions(const RecordData &Record, bool Complain,
                                     ASTReaderListener &Listener) {
FileSystemOptions FSOpts;
unsigned Idx = 0;
FSOpts.WorkingDir = ReadString(Record, Idx);
return Listener.ReadFileSystemOptions(FSOpts, Complain);
5842}

5844bool ASTReader::ParseHeaderSearchOptions(const RecordData &Record,
                                       bool Complain,
                                       ASTReaderListener &Listener) {
HeaderSearchOptions HSOpts;
unsigned Idx = 0;
HSOpts.Sysroot = ReadString(Record, Idx);

// Include entries.
for (unsigned N = Record[Idx++]; N; --N) {
  std::string Path = ReadString(Record, Idx);
  frontend::IncludeDirGroup Group
    = static_cast<frontend::IncludeDirGroup>(Record[Idx++]);
  bool IsFramework = Record[Idx++];
  bool IgnoreSysRoot = Record[Idx++];
  HSOpts.UserEntries.emplace_back(std::move(Path), Group, IsFramework,
                                  IgnoreSysRoot);
}

// System header prefixes.
for (unsigned N = Record[Idx++]; N; --N) {
  std::string Prefix = ReadString(Record, Idx);
  bool IsSystemHeader = Record[Idx++];
  HSOpts.SystemHeaderPrefixes.emplace_back(std::move(Prefix), IsSystemHeader);
}

HSOpts.ResourceDir = ReadString(Record, Idx);
HSOpts.ModuleCachePath = ReadString(Record, Idx);
HSOpts.ModuleUserBuildPath = ReadString(Record, Idx);
HSOpts.DisableModuleHash = Record[Idx++];
HSOpts.ImplicitModuleMaps = Record[Idx++];
HSOpts.ModuleMapFileHomeIsCwd = Record[Idx++];
HSOpts.EnablePrebuiltImplicitModules = Record[Idx++];
HSOpts.UseBuiltinIncludes = Record[Idx++];
HSOpts.UseStandardSystemIncludes = Record[Idx++];
HSOpts.UseStandardCXXIncludes = Record[Idx++];
HSOpts.UseLibcxx = Record[Idx++];
std::string SpecificModuleCachePath = ReadString(Record, Idx);

return Listener.ReadHeaderSearchOptions(HSOpts, SpecificModuleCachePath,
                                        Complain);
5884}

5886bool ASTReader::ParsePreprocessorOptions(const RecordData &Record,
                                       bool Complain,
                                       ASTReaderListener &Listener,
                                       std::string &SuggestedPredefines) {
PreprocessorOptions PPOpts;
unsigned Idx = 0;

// Macro definitions/undefs
for (unsigned N = Record[Idx++]; N; --N) {
  std::string Macro = ReadString(Record, Idx);
  bool IsUndef = Record[Idx++];
  PPOpts.Macros.push_back(std::make_pair(Macro, IsUndef));
}

// Includes
for (unsigned N = Record[Idx++]; N; --N) {
  PPOpts.Includes.push_back(ReadString(Record, Idx));
}

// Macro Includes
for (unsigned N = Record[Idx++]; N; --N) {
  PPOpts.MacroIncludes.push_back(ReadString(Record, Idx));
}

PPOpts.UsePredefines = Record[Idx++];
PPOpts.DetailedRecord = Record[Idx++];
PPOpts.ImplicitPCHInclude = ReadString(Record, Idx);
PPOpts.ObjCXXARCStandardLibrary =
  static_cast<ObjCXXARCStandardLibraryKind>(Record[Idx++]);
SuggestedPredefines.clear();
return Listener.ReadPreprocessorOptions(PPOpts, Complain,
                                        SuggestedPredefines);
5918}

5920std::pair<ModuleFile *, unsigned>
5921ASTReader::getModulePreprocessedEntity(unsigned GlobalIndex) {
GlobalPreprocessedEntityMapType::iterator
I = GlobalPreprocessedEntityMap.find(GlobalIndex);
assert(I != GlobalPreprocessedEntityMap.end() &&((void)0)
       "Corrupted global preprocessed entity map")((void)0);
ModuleFile *M = I->second;
unsigned LocalIndex = GlobalIndex - M->BasePreprocessedEntityID;
return std::make_pair(M, LocalIndex);
5929}

5931llvm::iterator_range<PreprocessingRecord::iterator>
5932ASTReader::getModulePreprocessedEntities(ModuleFile &Mod) const {
if (PreprocessingRecord *PPRec = PP.getPreprocessingRecord())
  return PPRec->getIteratorsForLoadedRange(Mod.BasePreprocessedEntityID,
                                           Mod.NumPreprocessedEntities);

return llvm::make_range(PreprocessingRecord::iterator(),
                        PreprocessingRecord::iterator());
5939}

5941bool ASTReader::canRecoverFromOutOfDate(StringRef ModuleFileName,
                                      unsigned int ClientLoadCapabilities) {
return ClientLoadCapabilities & ARR_OutOfDate &&
       !getModuleManager().getModuleCache().isPCMFinal(ModuleFileName);
5945}

5947llvm::iterator_range<ASTReader::ModuleDeclIterator>
5948ASTReader::getModuleFileLevelDecls(ModuleFile &Mod) {
return llvm::make_range(
    ModuleDeclIterator(this, &Mod, Mod.FileSortedDecls),
    ModuleDeclIterator(this, &Mod,
                       Mod.FileSortedDecls + Mod.NumFileSortedDecls));
5953}

5955SourceRange ASTReader::ReadSkippedRange(unsigned GlobalIndex) {
auto I = GlobalSkippedRangeMap.find(GlobalIndex);
assert(I != GlobalSkippedRangeMap.end() &&((void)0)
  "Corrupted global skipped range map")((void)0);
ModuleFile *M = I->second;
unsigned LocalIndex = GlobalIndex - M->BasePreprocessedSkippedRangeID;
assert(LocalIndex < M->NumPreprocessedSkippedRanges)((void)0);
PPSkippedRange RawRange = M->PreprocessedSkippedRangeOffsets[LocalIndex];
SourceRange Range(TranslateSourceLocation(*M, RawRange.getBegin()),
                  TranslateSourceLocation(*M, RawRange.getEnd()));
assert(Range.isValid())((void)0);
return Range;
5967}

5969PreprocessedEntity *ASTReader::ReadPreprocessedEntity(unsigned Index) {
PreprocessedEntityID PPID = Index+1;
std::pair<ModuleFile *, unsigned> PPInfo = getModulePreprocessedEntity(Index);
ModuleFile &M = *PPInfo.first;
unsigned LocalIndex = PPInfo.second;
const PPEntityOffset &PPOffs = M.PreprocessedEntityOffsets[LocalIndex];

if (!PP.getPreprocessingRecord()) {
  Error("no preprocessing record");
  return nullptr;
}

SavedStreamPosition SavedPosition(M.PreprocessorDetailCursor);
if (llvm::Error Err = M.PreprocessorDetailCursor.JumpToBit(
        M.MacroOffsetsBase + PPOffs.BitOffset)) {
  Error(std::move(Err));
  return nullptr;
}

Expected<llvm::BitstreamEntry> MaybeEntry =
    M.PreprocessorDetailCursor.advance(BitstreamCursor::AF_DontPopBlockAtEnd);
if (!MaybeEntry) {
  Error(MaybeEntry.takeError());
  return nullptr;
}
llvm::BitstreamEntry Entry = MaybeEntry.get();

if (Entry.Kind != llvm::BitstreamEntry::Record)
  return nullptr;

// Read the record.
SourceRange Range(TranslateSourceLocation(M, PPOffs.getBegin()),
                  TranslateSourceLocation(M, PPOffs.getEnd()));
PreprocessingRecord &PPRec = *PP.getPreprocessingRecord();
StringRef Blob;
RecordData Record;
Expected<unsigned> MaybeRecType =
    M.PreprocessorDetailCursor.readRecord(Entry.ID, Record, &Blob);
if (!MaybeRecType) {
  Error(MaybeRecType.takeError());
  return nullptr;
}
switch ((PreprocessorDetailRecordTypes)MaybeRecType.get()) {
case PPD_MACRO_EXPANSION: {
  bool isBuiltin = Record[0];
  IdentifierInfo *Name = nullptr;
  MacroDefinitionRecord *Def = nullptr;
  if (isBuiltin)
    Name = getLocalIdentifier(M, Record[1]);
  else {
    PreprocessedEntityID GlobalID =
        getGlobalPreprocessedEntityID(M, Record[1]);
    Def = cast<MacroDefinitionRecord>(
        PPRec.getLoadedPreprocessedEntity(GlobalID - 1));
  }

  MacroExpansion *ME;
  if (isBuiltin)
    ME = new (PPRec) MacroExpansion(Name, Range);
  else
    ME = new (PPRec) MacroExpansion(Def, Range);

  return ME;
}

case PPD_MACRO_DEFINITION: {
  // Decode the identifier info and then check again; if the macro is
  // still defined and associated with the identifier,
  IdentifierInfo *II = getLocalIdentifier(M, Record[0]);
  MacroDefinitionRecord *MD = new (PPRec) MacroDefinitionRecord(II, Range);

  if (DeserializationListener)
    DeserializationListener->MacroDefinitionRead(PPID, MD);

  return MD;
}

case PPD_INCLUSION_DIRECTIVE: {
  const char *FullFileNameStart = Blob.data() + Record[0];
  StringRef FullFileName(FullFileNameStart, Blob.size() - Record[0]);
  const FileEntry *File = nullptr;
  if (!FullFileName.empty())
    if (auto FE = PP.getFileManager().getFile(FullFileName))
      File = *FE;

  // FIXME: Stable encoding
  InclusionDirective::InclusionKind Kind
    = static_cast<InclusionDirective::InclusionKind>(Record[2]);
  InclusionDirective *ID
    = new (PPRec) InclusionDirective(PPRec, Kind,
                                     StringRef(Blob.data(), Record[0]),
                                     Record[1], Record[3],
                                     File,
                                     Range);
  return ID;
}
}

llvm_unreachable("Invalid PreprocessorDetailRecordTypes")__builtin_unreachable();
6068}

6070/// Find the next module that contains entities and return the ID
6071/// of the first entry.
6072///
6073/// \param SLocMapI points at a chunk of a module that contains no
6074/// preprocessed entities or the entities it contains are not the ones we are
6075/// looking for.
6076PreprocessedEntityID ASTReader::findNextPreprocessedEntity(
                     GlobalSLocOffsetMapType::const_iterator SLocMapI) const {
++SLocMapI;
for (GlobalSLocOffsetMapType::const_iterator
       EndI = GlobalSLocOffsetMap.end(); SLocMapI != EndI; ++SLocMapI) {
  ModuleFile &M = *SLocMapI->second;
  if (M.NumPreprocessedEntities)
    return M.BasePreprocessedEntityID;
}

return getTotalNumPreprocessedEntities();
6087}

6089namespace {

6091struct PPEntityComp {
const ASTReader &Reader;
ModuleFile &M;

PPEntityComp(const ASTReader &Reader, ModuleFile &M) : Reader(Reader), M(M) {}

bool operator()(const PPEntityOffset &L, const PPEntityOffset &R) const {
  SourceLocation LHS = getLoc(L);
  SourceLocation RHS = getLoc(R);
  return Reader.getSourceManager().isBeforeInTranslationUnit(LHS, RHS);
}

bool operator()(const PPEntityOffset &L, SourceLocation RHS) const {
  SourceLocation LHS = getLoc(L);
  return Reader.getSourceManager().isBeforeInTranslationUnit(LHS, RHS);
}

bool operator()(SourceLocation LHS, const PPEntityOffset &R) const {
  SourceLocation RHS = getLoc(R);
  return Reader.getSourceManager().isBeforeInTranslationUnit(LHS, RHS);
}

SourceLocation getLoc(const PPEntityOffset &PPE) const {
  return Reader.TranslateSourceLocation(M, PPE.getBegin());
}
6116};

6118} // namespace

6120PreprocessedEntityID ASTReader::findPreprocessedEntity(SourceLocation Loc,
                                                     bool EndsAfter) const {
if (SourceMgr.isLocalSourceLocation(Loc))
  return getTotalNumPreprocessedEntities();

GlobalSLocOffsetMapType::const_iterator SLocMapI = GlobalSLocOffsetMap.find(
    SourceManager::MaxLoadedOffset - Loc.getOffset() - 1);
assert(SLocMapI != GlobalSLocOffsetMap.end() &&((void)0)
       "Corrupted global sloc offset map")((void)0);

if (SLocMapI->second->NumPreprocessedEntities == 0)
  return findNextPreprocessedEntity(SLocMapI);

ModuleFile &M = *SLocMapI->second;

using pp_iterator = const PPEntityOffset *;

pp_iterator pp_begin = M.PreprocessedEntityOffsets;
pp_iterator pp_end = pp_begin + M.NumPreprocessedEntities;

size_t Count = M.NumPreprocessedEntities;
size_t Half;
pp_iterator First = pp_begin;
pp_iterator PPI;

if (EndsAfter) {
  PPI = std::upper_bound(pp_begin, pp_end, Loc,
                         PPEntityComp(*this, M));
} else {
  // Do a binary search manually instead of using std::lower_bound because
  // The end locations of entities may be unordered (when a macro expansion
  // is inside another macro argument), but for this case it is not important
  // whether we get the first macro expansion or its containing macro.
  while (Count > 0) {
    Half = Count / 2;
    PPI = First;
    std::advance(PPI, Half);
    if (SourceMgr.isBeforeInTranslationUnit(
            TranslateSourceLocation(M, PPI->getEnd()), Loc)) {
      First = PPI;
      ++First;
      Count = Count - Half - 1;
    } else
      Count = Half;
  }
}

if (PPI == pp_end)
  return findNextPreprocessedEntity(SLocMapI);

return M.BasePreprocessedEntityID + (PPI - pp_begin);
6171}

6173/// Returns a pair of [Begin, End) indices of preallocated
6174/// preprocessed entities that \arg Range encompasses.
6175std::pair<unsigned, unsigned>
  ASTReader::findPreprocessedEntitiesInRange(SourceRange Range) {
if (Range.isInvalid())
  return std::make_pair(0,0);
assert(!SourceMgr.isBeforeInTranslationUnit(Range.getEnd(),Range.getBegin()))((void)0);

PreprocessedEntityID BeginID =
    findPreprocessedEntity(Range.getBegin(), false);
PreprocessedEntityID EndID = findPreprocessedEntity(Range.getEnd(), true);
return std::make_pair(BeginID, EndID);
6185}

6187/// Optionally returns true or false if the preallocated preprocessed
6188/// entity with index \arg Index came from file \arg FID.
6189Optional<bool> ASTReader::isPreprocessedEntityInFileID(unsigned Index,
                                                           FileID FID) {
if (FID.isInvalid())
  return false;

std::pair<ModuleFile *, unsigned> PPInfo = getModulePreprocessedEntity(Index);
ModuleFile &M = *PPInfo.first;
unsigned LocalIndex = PPInfo.second;
const PPEntityOffset &PPOffs = M.PreprocessedEntityOffsets[LocalIndex];

SourceLocation Loc = TranslateSourceLocation(M, PPOffs.getBegin());
if (Loc.isInvalid())
  return false;

if (SourceMgr.isInFileID(SourceMgr.getFileLoc(Loc), FID))
  return true;
else
  return false;
6207}

6209namespace {

/// Visitor used to search for information about a header file.
class HeaderFileInfoVisitor {
  const FileEntry *FE;
  Optional<HeaderFileInfo> HFI;

public:
  explicit HeaderFileInfoVisitor(const FileEntry *FE) : FE(FE) {}

  bool operator()(ModuleFile &M) {
    HeaderFileInfoLookupTable *Table
      = static_cast<HeaderFileInfoLookupTable *>(M.HeaderFileInfoTable);
    if (!Table)
      return false;

    // Look in the on-disk hash table for an entry for this file name.
    HeaderFileInfoLookupTable::iterator Pos = Table->find(FE);
    if (Pos == Table->end())
      return false;

    HFI = *Pos;
    return true;
  }

  Optional<HeaderFileInfo> getHeaderFileInfo() const { return HFI; }
};

6237} // namespace

6