Bug Summary

File:src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Bitstream/BitstreamReader.h
Warning:line 221, column 39
The result of the right shift is undefined due to shifting by '64', which is greater or equal to the width of type 'llvm::SimpleBitstreamCursor::word_t'

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 MetadataLoader.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 pic -pic-level 1 -fhalf-no-semantic-interposition -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/libLLVM/obj -resource-dir /usr/local/lib/clang/13.0.0 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Analysis -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ASMParser -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/BinaryFormat -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Bitcode -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Bitcode -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Bitstream -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /include/llvm/CodeGen -I /include/llvm/CodeGen/PBQP -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/IR -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/IR -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms/Coroutines -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ProfileData/Coverage -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/DebugInfo/CodeView -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/DebugInfo/DWARF -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/DebugInfo -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/DebugInfo/MSF -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/DebugInfo/PDB -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Demangle -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ExecutionEngine -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ExecutionEngine/JITLink -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ExecutionEngine/Orc -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Frontend -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Frontend/OpenACC -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Frontend -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Frontend/OpenMP -I /include/llvm/CodeGen/GlobalISel -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/IRReader -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms/InstCombine -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/Transforms/InstCombine -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/LTO -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Linker -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/MC -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/MC/MCParser -I /include/llvm/CodeGen/MIRParser -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Object -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Option -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Passes -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ProfileData -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms/Scalar -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ADT -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Support -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/DebugInfo/Symbolize -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Target -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms/Utils -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms/Vectorize -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms/IPO -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include -I /usr/src/gnu/usr.bin/clang/libLLVM/../include -I /usr/src/gnu/usr.bin/clang/libLLVM/obj -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include -D NDEBUG -D __STDC_LIMIT_MACROS -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D LLVM_PREFIX="/usr" -D PIC -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/libLLVM/obj -ferror-limit 19 -fvisibility-inlines-hidden -fwrapv -D_RET_PROTECTOR -ret-protector -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/libLLVM/../../../llvm/llvm/lib/Bitcode/Reader/MetadataLoader.cpp

/usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Bitcode/Reader/MetadataLoader.cpp

→
1//===- MetadataLoader.cpp - Internal BitcodeReader implementation ---------===//
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#include "MetadataLoader.h"
10#include "ValueList.h"
11
12#include "llvm/ADT/APFloat.h"
13#include "llvm/ADT/APInt.h"
14#include "llvm/ADT/ArrayRef.h"
15#include "llvm/ADT/DenseMap.h"
16#include "llvm/ADT/DenseSet.h"
17#include "llvm/ADT/None.h"
18#include "llvm/ADT/STLExtras.h"
19#include "llvm/ADT/SmallString.h"
20#include "llvm/ADT/Statistic.h"
21#include "llvm/ADT/StringRef.h"
22#include "llvm/ADT/Twine.h"
23#include "llvm/Bitcode/BitcodeReader.h"
24#include "llvm/Bitstream/BitstreamReader.h"
25#include "llvm/Bitcode/LLVMBitCodes.h"
26#include "llvm/IR/Argument.h"
27#include "llvm/IR/Attributes.h"
28#include "llvm/IR/AutoUpgrade.h"
29#include "llvm/IR/BasicBlock.h"
30#include "llvm/IR/CallingConv.h"
31#include "llvm/IR/Comdat.h"
32#include "llvm/IR/Constant.h"
33#include "llvm/IR/Constants.h"
34#include "llvm/IR/DebugInfo.h"
35#include "llvm/IR/DebugInfoMetadata.h"
36#include "llvm/IR/DebugLoc.h"
37#include "llvm/IR/DerivedTypes.h"
38#include "llvm/IR/DiagnosticPrinter.h"
39#include "llvm/IR/Function.h"
40#include "llvm/IR/GVMaterializer.h"
41#include "llvm/IR/GlobalAlias.h"
42#include "llvm/IR/GlobalIFunc.h"
43#include "llvm/IR/GlobalIndirectSymbol.h"
44#include "llvm/IR/GlobalObject.h"
45#include "llvm/IR/GlobalValue.h"
46#include "llvm/IR/GlobalVariable.h"
47#include "llvm/IR/InlineAsm.h"
48#include "llvm/IR/InstrTypes.h"
49#include "llvm/IR/Instruction.h"
50#include "llvm/IR/Instructions.h"
51#include "llvm/IR/IntrinsicInst.h"
52#include "llvm/IR/Intrinsics.h"
53#include "llvm/IR/LLVMContext.h"
54#include "llvm/IR/Module.h"
55#include "llvm/IR/ModuleSummaryIndex.h"
56#include "llvm/IR/OperandTraits.h"
57#include "llvm/IR/TrackingMDRef.h"
58#include "llvm/IR/Type.h"
59#include "llvm/IR/ValueHandle.h"
60#include "llvm/Support/AtomicOrdering.h"
61#include "llvm/Support/Casting.h"
62#include "llvm/Support/CommandLine.h"
63#include "llvm/Support/Compiler.h"
64#include "llvm/Support/Debug.h"
65#include "llvm/Support/ErrorHandling.h"
66#include "llvm/Support/ManagedStatic.h"
67#include "llvm/Support/MemoryBuffer.h"
68#include "llvm/Support/raw_ostream.h"
69#include <algorithm>
70#include <cassert>
71#include <cstddef>
72#include <cstdint>
73#include <deque>
74#include <limits>
75#include <map>
76#include <string>
77#include <system_error>
78#include <tuple>
79#include <utility>
80#include <vector>
81
82using namespace llvm;
83
84#define DEBUG_TYPE"bitcode-reader" "bitcode-reader"
85
86STATISTIC(NumMDStringLoaded, "Number of MDStrings loaded")static llvm::Statistic NumMDStringLoaded = {"bitcode-reader",
"NumMDStringLoaded", "Number of MDStrings loaded"};
87STATISTIC(NumMDNodeTemporary, "Number of MDNode::Temporary created")static llvm::Statistic NumMDNodeTemporary = {"bitcode-reader"
, "NumMDNodeTemporary", "Number of MDNode::Temporary created"
};
88STATISTIC(NumMDRecordLoaded, "Number of Metadata records loaded")static llvm::Statistic NumMDRecordLoaded = {"bitcode-reader",
"NumMDRecordLoaded", "Number of Metadata records loaded"};
89
90/// Flag whether we need to import full type definitions for ThinLTO.
91/// Currently needed for Darwin and LLDB.
92static cl::opt<bool> ImportFullTypeDefinitions(
93 "import-full-type-definitions", cl::init(false), cl::Hidden,
94 cl::desc("Import full type definitions for ThinLTO."));
95
96static cl::opt<bool> DisableLazyLoading(
97 "disable-ondemand-mds-loading", cl::init(false), cl::Hidden,
98 cl::desc("Force disable the lazy-loading on-demand of metadata when "
99 "loading bitcode for importing."));
100
101namespace {
102
103static int64_t unrotateSign(uint64_t U) { return (U & 1) ? ~(U >> 1) : U >> 1; }
104
105class BitcodeReaderMetadataList {
106 /// Array of metadata references.
107 ///
108 /// Don't use std::vector here. Some versions of libc++ copy (instead of
109 /// move) on resize, and TrackingMDRef is very expensive to copy.
110 SmallVector<TrackingMDRef, 1> MetadataPtrs;
111
112 /// The set of indices in MetadataPtrs above of forward references that were
113 /// generated.
114 SmallDenseSet<unsigned, 1> ForwardReference;
115
116 /// The set of indices in MetadataPtrs above of Metadata that need to be
117 /// resolved.
118 SmallDenseSet<unsigned, 1> UnresolvedNodes;
119
120 /// Structures for resolving old type refs.
121 struct {
122 SmallDenseMap<MDString *, TempMDTuple, 1> Unknown;
123 SmallDenseMap<MDString *, DICompositeType *, 1> Final;
124 SmallDenseMap<MDString *, DICompositeType *, 1> FwdDecls;
125 SmallVector<std::pair<TrackingMDRef, TempMDTuple>, 1> Arrays;
126 } OldTypeRefs;
127
128 LLVMContext &Context;
129
130 /// Maximum number of valid references. Forward references exceeding the
131 /// maximum must be invalid.
132 unsigned RefsUpperBound;
133
134public:
135 BitcodeReaderMetadataList(LLVMContext &C, size_t RefsUpperBound)
136 : Context(C),
137 RefsUpperBound(std::min((size_t)std::numeric_limits<unsigned>::max(),
138 RefsUpperBound)) {}
139
140 // vector compatibility methods
141 unsigned size() const { return MetadataPtrs.size(); }
142 void resize(unsigned N) { MetadataPtrs.resize(N); }
143 void push_back(Metadata *MD) { MetadataPtrs.emplace_back(MD); }
144 void clear() { MetadataPtrs.clear(); }
145 Metadata *back() const { return MetadataPtrs.back(); }
146 void pop_back() { MetadataPtrs.pop_back(); }
147 bool empty() const { return MetadataPtrs.empty(); }
148
149 Metadata *operator[](unsigned i) const {
150 assert(i < MetadataPtrs.size())((void)0);
151 return MetadataPtrs[i];
152 }
153
154 Metadata *lookup(unsigned I) const {
155 if (I < MetadataPtrs.size())
156 return MetadataPtrs[I];
157 return nullptr;
158 }
159
160 void shrinkTo(unsigned N) {
161 assert(N <= size() && "Invalid shrinkTo request!")((void)0);
162 assert(ForwardReference.empty() && "Unexpected forward refs")((void)0);
163 assert(UnresolvedNodes.empty() && "Unexpected unresolved node")((void)0);
164 MetadataPtrs.resize(N);
165 }
166
167 /// Return the given metadata, creating a replaceable forward reference if
168 /// necessary.
169 Metadata *getMetadataFwdRef(unsigned Idx);
170
171 /// Return the given metadata only if it is fully resolved.
172 ///
173 /// Gives the same result as \a lookup(), unless \a MDNode::isResolved()
174 /// would give \c false.
175 Metadata *getMetadataIfResolved(unsigned Idx);
176
177 MDNode *getMDNodeFwdRefOrNull(unsigned Idx);
178 void assignValue(Metadata *MD, unsigned Idx);
179 void tryToResolveCycles();
180 bool hasFwdRefs() const { return !ForwardReference.empty(); }
181 int getNextFwdRef() {
182 assert(hasFwdRefs())((void)0);
183 return *ForwardReference.begin();
184 }
185
186 /// Upgrade a type that had an MDString reference.
187 void addTypeRef(MDString &UUID, DICompositeType &CT);
188
189 /// Upgrade a type that had an MDString reference.
190 Metadata *upgradeTypeRef(Metadata *MaybeUUID);
191
192 /// Upgrade a type ref array that may have MDString references.
193 Metadata *upgradeTypeRefArray(Metadata *MaybeTuple);
194
195private:
196 Metadata *resolveTypeRefArray(Metadata *MaybeTuple);
197};
198
199void BitcodeReaderMetadataList::assignValue(Metadata *MD, unsigned Idx) {
200 if (auto *MDN = dyn_cast<MDNode>(MD))
201 if (!MDN->isResolved())
202 UnresolvedNodes.insert(Idx);
203
204 if (Idx == size()) {
205 push_back(MD);
206 return;
207 }
208
209 if (Idx >= size())
210 resize(Idx + 1);
211
212 TrackingMDRef &OldMD = MetadataPtrs[Idx];
213 if (!OldMD) {
214 OldMD.reset(MD);
215 return;
216 }
217
218 // If there was a forward reference to this value, replace it.
219 TempMDTuple PrevMD(cast<MDTuple>(OldMD.get()));
220 PrevMD->replaceAllUsesWith(MD);
221 ForwardReference.erase(Idx);
222}
223
224Metadata *BitcodeReaderMetadataList::getMetadataFwdRef(unsigned Idx) {
225 // Bail out for a clearly invalid value.
226 if (Idx >= RefsUpperBound)
227 return nullptr;
228
229 if (Idx >= size())
230 resize(Idx + 1);
231
232 if (Metadata *MD = MetadataPtrs[Idx])
233 return MD;
234
235 // Track forward refs to be resolved later.
236 ForwardReference.insert(Idx);
237
238 // Create and return a placeholder, which will later be RAUW'd.
239 ++NumMDNodeTemporary;
240 Metadata *MD = MDNode::getTemporary(Context, None).release();
241 MetadataPtrs[Idx].reset(MD);
242 return MD;
243}
244
245Metadata *BitcodeReaderMetadataList::getMetadataIfResolved(unsigned Idx) {
246 Metadata *MD = lookup(Idx);
247 if (auto *N = dyn_cast_or_null<MDNode>(MD))
248 if (!N->isResolved())
249 return nullptr;
250 return MD;
251}
252
253MDNode *BitcodeReaderMetadataList::getMDNodeFwdRefOrNull(unsigned Idx) {
254 return dyn_cast_or_null<MDNode>(getMetadataFwdRef(Idx));
255}
256
257void BitcodeReaderMetadataList::tryToResolveCycles() {
258 if (!ForwardReference.empty())
259 // Still forward references... can't resolve cycles.
260 return;
261
262 // Give up on finding a full definition for any forward decls that remain.
263 for (const auto &Ref : OldTypeRefs.FwdDecls)
264 OldTypeRefs.Final.insert(Ref);
265 OldTypeRefs.FwdDecls.clear();
266
267 // Upgrade from old type ref arrays. In strange cases, this could add to
268 // OldTypeRefs.Unknown.
269 for (const auto &Array : OldTypeRefs.Arrays)
270 Array.second->replaceAllUsesWith(resolveTypeRefArray(Array.first.get()));
271 OldTypeRefs.Arrays.clear();
272
273 // Replace old string-based type refs with the resolved node, if possible.
274 // If we haven't seen the node, leave it to the verifier to complain about
275 // the invalid string reference.
276 for (const auto &Ref : OldTypeRefs.Unknown) {
277 if (DICompositeType *CT = OldTypeRefs.Final.lookup(Ref.first))
278 Ref.second->replaceAllUsesWith(CT);
279 else
280 Ref.second->replaceAllUsesWith(Ref.first);
281 }
282 OldTypeRefs.Unknown.clear();
283
284 if (UnresolvedNodes.empty())
285 // Nothing to do.
286 return;
287
288 // Resolve any cycles.
289 for (unsigned I : UnresolvedNodes) {
290 auto &MD = MetadataPtrs[I];
291 auto *N = dyn_cast_or_null<MDNode>(MD);
292 if (!N)
293 continue;
294
295 assert(!N->isTemporary() && "Unexpected forward reference")((void)0);
296 N->resolveCycles();
297 }
298
299 // Make sure we return early again until there's another unresolved ref.
300 UnresolvedNodes.clear();
301}
302
303void BitcodeReaderMetadataList::addTypeRef(MDString &UUID,
304 DICompositeType &CT) {
305 assert(CT.getRawIdentifier() == &UUID && "Mismatched UUID")((void)0);
306 if (CT.isForwardDecl())
307 OldTypeRefs.FwdDecls.insert(std::make_pair(&UUID, &CT));
308 else
309 OldTypeRefs.Final.insert(std::make_pair(&UUID, &CT));
310}
311
312Metadata *BitcodeReaderMetadataList::upgradeTypeRef(Metadata *MaybeUUID) {
313 auto *UUID = dyn_cast_or_null<MDString>(MaybeUUID);
314 if (LLVM_LIKELY(!UUID)__builtin_expect((bool)(!UUID), true))
315 return MaybeUUID;
316
317 if (auto *CT = OldTypeRefs.Final.lookup(UUID))
318 return CT;
319
320 auto &Ref = OldTypeRefs.Unknown[UUID];
321 if (!Ref)
322 Ref = MDNode::getTemporary(Context, None);
323 return Ref.get();
324}
325
326Metadata *BitcodeReaderMetadataList::upgradeTypeRefArray(Metadata *MaybeTuple) {
327 auto *Tuple = dyn_cast_or_null<MDTuple>(MaybeTuple);
328 if (!Tuple || Tuple->isDistinct())
329 return MaybeTuple;
330
331 // Look through the array immediately if possible.
332 if (!Tuple->isTemporary())
333 return resolveTypeRefArray(Tuple);
334
335 // Create and return a placeholder to use for now. Eventually
336 // resolveTypeRefArrays() will be resolve this forward reference.
337 OldTypeRefs.Arrays.emplace_back(
338 std::piecewise_construct, std::forward_as_tuple(Tuple),
339 std::forward_as_tuple(MDTuple::getTemporary(Context, None)));
340 return OldTypeRefs.Arrays.back().second.get();
341}
342
343Metadata *BitcodeReaderMetadataList::resolveTypeRefArray(Metadata *MaybeTuple) {
344 auto *Tuple = dyn_cast_or_null<MDTuple>(MaybeTuple);
345 if (!Tuple || Tuple->isDistinct())
346 return MaybeTuple;
347
348 // Look through the DITypeRefArray, upgrading each DIType *.
349 SmallVector<Metadata *, 32> Ops;
350 Ops.reserve(Tuple->getNumOperands());
351 for (Metadata *MD : Tuple->operands())
352 Ops.push_back(upgradeTypeRef(MD));
353
354 return MDTuple::get(Context, Ops);
355}
356
357namespace {
358
359class PlaceholderQueue {
360 // Placeholders would thrash around when moved, so store in a std::deque
361 // instead of some sort of vector.
362 std::deque<DistinctMDOperandPlaceholder> PHs;
363
364public:
365 ~PlaceholderQueue() {
366 assert(empty() && "PlaceholderQueue hasn't been flushed before being destroyed")((void)0);
367 }
368 bool empty() const { return PHs.empty(); }
369 DistinctMDOperandPlaceholder &getPlaceholderOp(unsigned ID);
370 void flush(BitcodeReaderMetadataList &MetadataList);
371
372 /// Return the list of temporaries nodes in the queue, these need to be
373 /// loaded before we can flush the queue.
374 void getTemporaries(BitcodeReaderMetadataList &MetadataList,
375 DenseSet<unsigned> &Temporaries) {
376 for (auto &PH : PHs) {
377 auto ID = PH.getID();
378 auto *MD = MetadataList.lookup(ID);
379 if (!MD) {
380 Temporaries.insert(ID);
381 continue;
382 }
383 auto *N = dyn_cast_or_null<MDNode>(MD);
384 if (N && N->isTemporary())
385 Temporaries.insert(ID);
386 }
387 }
388};
389
390} // end anonymous namespace
391
392DistinctMDOperandPlaceholder &PlaceholderQueue::getPlaceholderOp(unsigned ID) {
393 PHs.emplace_back(ID);
394 return PHs.back();
395}
396
397void PlaceholderQueue::flush(BitcodeReaderMetadataList &MetadataList) {
398 while (!PHs.empty()) {
399 auto *MD = MetadataList.lookup(PHs.front().getID());
400 assert(MD && "Flushing placeholder on unassigned MD")((void)0);
401#ifndef NDEBUG1
402 if (auto *MDN = dyn_cast<MDNode>(MD))
403 assert(MDN->isResolved() &&((void)0)
404 "Flushing Placeholder while cycles aren't resolved")((void)0);
405#endif
406 PHs.front().replaceUseWith(MD);
407 PHs.pop_front();
408 }
409}
410
411} // anonymous namespace
412
413static Error error(const Twine &Message) {
414 return make_error<StringError>(
415 Message, make_error_code(BitcodeError::CorruptedBitcode));
416}
417
418class MetadataLoader::MetadataLoaderImpl {
419 BitcodeReaderMetadataList MetadataList;
420 BitcodeReaderValueList &ValueList;
421 BitstreamCursor &Stream;
422 LLVMContext &Context;
423 Module &TheModule;
424 std::function<Type *(unsigned)> getTypeByID;
425
426 /// Cursor associated with the lazy-loading of Metadata. This is the easy way
427 /// to keep around the right "context" (Abbrev list) to be able to jump in
428 /// the middle of the metadata block and load any record.
429 BitstreamCursor IndexCursor;
430
431 /// Index that keeps track of MDString values.
432 std::vector<StringRef> MDStringRef;
433
434 /// On-demand loading of a single MDString. Requires the index above to be
435 /// populated.
436 MDString *lazyLoadOneMDString(unsigned Idx);
437
438 /// Index that keeps track of where to find a metadata record in the stream.
439 std::vector<uint64_t> GlobalMetadataBitPosIndex;
440
441 /// Cursor position of the start of the global decl attachments, to enable
442 /// loading using the index built for lazy loading, instead of forward
443 /// references.
444 uint64_t GlobalDeclAttachmentPos = 0;
445
446#ifndef NDEBUG1
447 /// Sanity check that we end up parsing all of the global decl attachments.
448 unsigned NumGlobalDeclAttachSkipped = 0;
449 unsigned NumGlobalDeclAttachParsed = 0;
450#endif
451
452 /// Load the global decl attachments, using the index built for lazy loading.
453 Expected<bool> loadGlobalDeclAttachments();
454
455 /// Populate the index above to enable lazily loading of metadata, and load
456 /// the named metadata as well as the transitively referenced global
457 /// Metadata.
458 Expected<bool> lazyLoadModuleMetadataBlock();
459
460 /// On-demand loading of a single metadata. Requires the index above to be
461 /// populated.
462 void lazyLoadOneMetadata(unsigned Idx, PlaceholderQueue &Placeholders);
463
464 // Keep mapping of seens pair of old-style CU <-> SP, and update pointers to
465 // point from SP to CU after a block is completly parsed.
466 std::vector<std::pair<DICompileUnit *, Metadata *>> CUSubprograms;
467
468 /// Functions that need to be matched with subprograms when upgrading old
469 /// metadata.
470 SmallDenseMap<Function *, DISubprogram *, 16> FunctionsWithSPs;
471
472 // Map the bitcode's custom MDKind ID to the Module's MDKind ID.
473 DenseMap<unsigned, unsigned> MDKindMap;
474
475 bool StripTBAA = false;
476 bool HasSeenOldLoopTags = false;
477 bool NeedUpgradeToDIGlobalVariableExpression = false;
478 bool NeedDeclareExpressionUpgrade = false;
479
480 /// True if metadata is being parsed for a module being ThinLTO imported.
481 bool IsImporting = false;
482
483 Error parseOneMetadata(SmallVectorImpl<uint64_t> &Record, unsigned Code,
484 PlaceholderQueue &Placeholders, StringRef Blob,
485 unsigned &NextMetadataNo);
486 Error parseMetadataStrings(ArrayRef<uint64_t> Record, StringRef Blob,
487 function_ref<void(StringRef)> CallBack);
488 Error parseGlobalObjectAttachment(GlobalObject &GO,
489 ArrayRef<uint64_t> Record);
490 Error parseMetadataKindRecord(SmallVectorImpl<uint64_t> &Record);
491
492 void resolveForwardRefsAndPlaceholders(PlaceholderQueue &Placeholders);
493
494 /// Upgrade old-style CU <-> SP pointers to point from SP to CU.
495 void upgradeCUSubprograms() {
496 for (auto CU_SP : CUSubprograms)
497 if (auto *SPs = dyn_cast_or_null<MDTuple>(CU_SP.second))
498 for (auto &Op : SPs->operands())
499 if (auto *SP = dyn_cast_or_null<DISubprogram>(Op))
500 SP->replaceUnit(CU_SP.first);
501 CUSubprograms.clear();
502 }
503
504 /// Upgrade old-style bare DIGlobalVariables to DIGlobalVariableExpressions.
505 void upgradeCUVariables() {
506 if (!NeedUpgradeToDIGlobalVariableExpression)
507 return;
508
509 // Upgrade list of variables attached to the CUs.
510 if (NamedMDNode *CUNodes = TheModule.getNamedMetadata("llvm.dbg.cu"))
511 for (unsigned I = 0, E = CUNodes->getNumOperands(); I != E; ++I) {
512 auto *CU = cast<DICompileUnit>(CUNodes->getOperand(I));
513 if (auto *GVs = dyn_cast_or_null<MDTuple>(CU->getRawGlobalVariables()))
514 for (unsigned I = 0; I < GVs->getNumOperands(); I++)
515 if (auto *GV =
516 dyn_cast_or_null<DIGlobalVariable>(GVs->getOperand(I))) {
517 auto *DGVE = DIGlobalVariableExpression::getDistinct(
518 Context, GV, DIExpression::get(Context, {}));
519 GVs->replaceOperandWith(I, DGVE);
520 }
521 }
522
523 // Upgrade variables attached to globals.
524 for (auto &GV : TheModule.globals()) {
525 SmallVector<MDNode *, 1> MDs;
526 GV.getMetadata(LLVMContext::MD_dbg, MDs);
527 GV.eraseMetadata(LLVMContext::MD_dbg);
528 for (auto *MD : MDs)
529 if (auto *DGV = dyn_cast<DIGlobalVariable>(MD)) {
530 auto *DGVE = DIGlobalVariableExpression::getDistinct(
531 Context, DGV, DIExpression::get(Context, {}));
532 GV.addMetadata(LLVMContext::MD_dbg, *DGVE);
533 } else
534 GV.addMetadata(LLVMContext::MD_dbg, *MD);
535 }
536 }
537
538 /// Remove a leading DW_OP_deref from DIExpressions in a dbg.declare that
539 /// describes a function argument.
540 void upgradeDeclareExpressions(Function &F) {
541 if (!NeedDeclareExpressionUpgrade)
542 return;
543
544 for (auto &BB : F)
545 for (auto &I : BB)
546 if (auto *DDI = dyn_cast<DbgDeclareInst>(&I))
547 if (auto *DIExpr = DDI->getExpression())
548 if (DIExpr->startsWithDeref() &&
549 dyn_cast_or_null<Argument>(DDI->getAddress())) {
550 SmallVector<uint64_t, 8> Ops;
551 Ops.append(std::next(DIExpr->elements_begin()),
552 DIExpr->elements_end());
553 DDI->setExpression(DIExpression::get(Context, Ops));
554 }
555 }
556
557 /// Upgrade the expression from previous versions.
558 Error upgradeDIExpression(uint64_t FromVersion,
559 MutableArrayRef<uint64_t> &Expr,
560 SmallVectorImpl<uint64_t> &Buffer) {
561 auto N = Expr.size();
562 switch (FromVersion) {
563 default:
564 return error("Invalid record");
565 case 0:
566 if (N >= 3 && Expr[N - 3] == dwarf::DW_OP_bit_piece)
567 Expr[N - 3] = dwarf::DW_OP_LLVM_fragment;
568 LLVM_FALLTHROUGH[[gnu::fallthrough]];
569 case 1:
570 // Move DW_OP_deref to the end.
571 if (N && Expr[0] == dwarf::DW_OP_deref) {
572 auto End = Expr.end();
573 if (Expr.size() >= 3 &&
574 *std::prev(End, 3) == dwarf::DW_OP_LLVM_fragment)
575 End = std::prev(End, 3);
576 std::move(std::next(Expr.begin()), End, Expr.begin());
577 *std::prev(End) = dwarf::DW_OP_deref;
578 }
579 NeedDeclareExpressionUpgrade = true;
580 LLVM_FALLTHROUGH[[gnu::fallthrough]];
581 case 2: {
582 // Change DW_OP_plus to DW_OP_plus_uconst.
583 // Change DW_OP_minus to DW_OP_uconst, DW_OP_minus
584 auto SubExpr = ArrayRef<uint64_t>(Expr);
585 while (!SubExpr.empty()) {
586 // Skip past other operators with their operands
587 // for this version of the IR, obtained from
588 // from historic DIExpression::ExprOperand::getSize().
589 size_t HistoricSize;
590 switch (SubExpr.front()) {
591 default:
592 HistoricSize = 1;
593 break;
594 case dwarf::DW_OP_constu:
595 case dwarf::DW_OP_minus:
596 case dwarf::DW_OP_plus:
597 HistoricSize = 2;
598 break;
599 case dwarf::DW_OP_LLVM_fragment:
600 HistoricSize = 3;
601 break;
602 }
603
604 // If the expression is malformed, make sure we don't
605 // copy more elements than we should.
606 HistoricSize = std::min(SubExpr.size(), HistoricSize);
607 ArrayRef<uint64_t> Args = SubExpr.slice(1, HistoricSize-1);
608
609 switch (SubExpr.front()) {
610 case dwarf::DW_OP_plus:
611 Buffer.push_back(dwarf::DW_OP_plus_uconst);
612 Buffer.append(Args.begin(), Args.end());
613 break;
614 case dwarf::DW_OP_minus:
615 Buffer.push_back(dwarf::DW_OP_constu);
616 Buffer.append(Args.begin(), Args.end());
617 Buffer.push_back(dwarf::DW_OP_minus);
618 break;
619 default:
620 Buffer.push_back(*SubExpr.begin());
621 Buffer.append(Args.begin(), Args.end());
622 break;
623 }
624
625 // Continue with remaining elements.
626 SubExpr = SubExpr.slice(HistoricSize);
627 }
628 Expr = MutableArrayRef<uint64_t>(Buffer);
629 LLVM_FALLTHROUGH[[gnu::fallthrough]];
630 }
631 case 3:
632 // Up-to-date!
633 break;
634 }
635
636 return Error::success();
637 }
638
639 void upgradeDebugInfo() {
640 upgradeCUSubprograms();
641 upgradeCUVariables();
642 }
643
644public:
645 MetadataLoaderImpl(BitstreamCursor &Stream, Module &TheModule,
646 BitcodeReaderValueList &ValueList,
647 std::function<Type *(unsigned)> getTypeByID,
648 bool IsImporting)
649 : MetadataList(TheModule.getContext(), Stream.SizeInBytes()),
650 ValueList(ValueList), Stream(Stream), Context(TheModule.getContext()),
651 TheModule(TheModule), getTypeByID(std::move(getTypeByID)),
652 IsImporting(IsImporting) {}
653
654 Error parseMetadata(bool ModuleLevel);
655
656 bool hasFwdRefs() const { return MetadataList.hasFwdRefs(); }
657
658 Metadata *getMetadataFwdRefOrLoad(unsigned ID) {
659 if (ID < MDStringRef.size())
660 return lazyLoadOneMDString(ID);
661 if (auto *MD = MetadataList.lookup(ID))
662 return MD;
663 // If lazy-loading is enabled, we try recursively to load the operand
664 // instead of creating a temporary.
665 if (ID < (MDStringRef.size() + GlobalMetadataBitPosIndex.size())) {
666 PlaceholderQueue Placeholders;
667 lazyLoadOneMetadata(ID, Placeholders);
668 resolveForwardRefsAndPlaceholders(Placeholders);
669 return MetadataList.lookup(ID);
670 }
671 return MetadataList.getMetadataFwdRef(ID);
672 }
673
674 DISubprogram *lookupSubprogramForFunction(Function *F) {
675 return FunctionsWithSPs.lookup(F);
676 }
677
678 bool hasSeenOldLoopTags() const { return HasSeenOldLoopTags; }
679
680 Error parseMetadataAttachment(
681 Function &F, const SmallVectorImpl<Instruction *> &InstructionList);
682
683 Error parseMetadataKinds();
684
685 void setStripTBAA(bool Value) { StripTBAA = Value; }
686 bool isStrippingTBAA() const { return StripTBAA; }
687
688 unsigned size() const { return MetadataList.size(); }
689 void shrinkTo(unsigned N) { MetadataList.shrinkTo(N); }
690 void upgradeDebugIntrinsics(Function &F) { upgradeDeclareExpressions(F); }
691};
692
693Expected<bool>
694MetadataLoader::MetadataLoaderImpl::lazyLoadModuleMetadataBlock() {
695 IndexCursor = Stream;
696 SmallVector<uint64_t, 64> Record;
697 GlobalDeclAttachmentPos = 0;
698 // Get the abbrevs, and preload record positions to make them lazy-loadable.
699 while (true) {
700 uint64_t SavedPos = IndexCursor.GetCurrentBitNo();
701 Expected<BitstreamEntry> MaybeEntry = IndexCursor.advanceSkippingSubblocks(
702 BitstreamCursor::AF_DontPopBlockAtEnd);
703 if (!MaybeEntry)
704 return MaybeEntry.takeError();
705 BitstreamEntry Entry = MaybeEntry.get();
706
707 switch (Entry.Kind) {
708 case BitstreamEntry::SubBlock: // Handled for us already.
709 case BitstreamEntry::Error:
710 return error("Malformed block");
711 case BitstreamEntry::EndBlock: {
712 return true;
713 }
714 case BitstreamEntry::Record: {
715 // The interesting case.
716 ++NumMDRecordLoaded;
717 uint64_t CurrentPos = IndexCursor.GetCurrentBitNo();
718 Expected<unsigned> MaybeCode = IndexCursor.skipRecord(Entry.ID);
719 if (!MaybeCode)
720 return MaybeCode.takeError();
721 unsigned Code = MaybeCode.get();
722 switch (Code) {
723 case bitc::METADATA_STRINGS: {
724 // Rewind and parse the strings.
725 if (Error Err = IndexCursor.JumpToBit(CurrentPos))
726 return std::move(Err);
727 StringRef Blob;
728 Record.clear();
729 if (Expected<unsigned> MaybeRecord =
730 IndexCursor.readRecord(Entry.ID, Record, &Blob))
731 ;
732 else
733 return MaybeRecord.takeError();
734 unsigned NumStrings = Record[0];
735 MDStringRef.reserve(NumStrings);
736 auto IndexNextMDString = [&](StringRef Str) {
737 MDStringRef.push_back(Str);
738 };
739 if (auto Err = parseMetadataStrings(Record, Blob, IndexNextMDString))
740 return std::move(Err);
741 break;
742 }
743 case bitc::METADATA_INDEX_OFFSET: {
744 // This is the offset to the index, when we see this we skip all the
745 // records and load only an index to these.
746 if (Error Err = IndexCursor.JumpToBit(CurrentPos))
747 return std::move(Err);
748 Record.clear();
749 if (Expected<unsigned> MaybeRecord =
750 IndexCursor.readRecord(Entry.ID, Record))
751 ;
752 else
753 return MaybeRecord.takeError();
754 if (Record.size() != 2)
755 return error("Invalid record");
756 auto Offset = Record[0] + (Record[1] << 32);
757 auto BeginPos = IndexCursor.GetCurrentBitNo();
758 if (Error Err = IndexCursor.JumpToBit(BeginPos + Offset))
759 return std::move(Err);
760 Expected<BitstreamEntry> MaybeEntry =
761 IndexCursor.advanceSkippingSubblocks(
762 BitstreamCursor::AF_DontPopBlockAtEnd);
763 if (!MaybeEntry)
764 return MaybeEntry.takeError();
765 Entry = MaybeEntry.get();
766 assert(Entry.Kind == BitstreamEntry::Record &&((void)0)
767 "Corrupted bitcode: Expected `Record` when trying to find the "((void)0)
768 "Metadata index")((void)0);
769 Record.clear();
770 if (Expected<unsigned> MaybeCode =
771 IndexCursor.readRecord(Entry.ID, Record))
772 assert(MaybeCode.get() == bitc::METADATA_INDEX &&((void)0)
773 "Corrupted bitcode: Expected `METADATA_INDEX` when trying to "((void)0)
774 "find the Metadata index")((void)0);
775 else
776 return MaybeCode.takeError();
777 // Delta unpack
778 auto CurrentValue = BeginPos;
779 GlobalMetadataBitPosIndex.reserve(Record.size());
780 for (auto &Elt : Record) {
781 CurrentValue += Elt;
782 GlobalMetadataBitPosIndex.push_back(CurrentValue);
783 }
784 break;
785 }
786 case bitc::METADATA_INDEX:
787 // We don't expect to get there, the Index is loaded when we encounter
788 // the offset.
789 return error("Corrupted Metadata block");
790 case bitc::METADATA_NAME: {
791 // Named metadata need to be materialized now and aren't deferred.
792 if (Error Err = IndexCursor.JumpToBit(CurrentPos))
793 return std::move(Err);
794 Record.clear();
795
796 unsigned Code;
797 if (Expected<unsigned> MaybeCode =
798 IndexCursor.readRecord(Entry.ID, Record)) {
799 Code = MaybeCode.get();
800 assert(Code == bitc::METADATA_NAME)((void)0);
801 } else
802 return MaybeCode.takeError();
803
804 // Read name of the named metadata.
805 SmallString<8> Name(Record.begin(), Record.end());
806 if (Expected<unsigned> MaybeCode = IndexCursor.ReadCode())
807 Code = MaybeCode.get();
808 else
809 return MaybeCode.takeError();
810
811 // Named Metadata comes in two parts, we expect the name to be followed
812 // by the node
813 Record.clear();
814 if (Expected<unsigned> MaybeNextBitCode =
815 IndexCursor.readRecord(Code, Record))
816 assert(MaybeNextBitCode.get() == bitc::METADATA_NAMED_NODE)((void)0);
817 else
818 return MaybeNextBitCode.takeError();
819
820 // Read named metadata elements.
821 unsigned Size = Record.size();
822 NamedMDNode *NMD = TheModule.getOrInsertNamedMetadata(Name);
823 for (unsigned i = 0; i != Size; ++i) {
824 // FIXME: We could use a placeholder here, however NamedMDNode are
825 // taking MDNode as operand and not using the Metadata infrastructure.
826 // It is acknowledged by 'TODO: Inherit from Metadata' in the
827 // NamedMDNode class definition.
828 MDNode *MD = MetadataList.getMDNodeFwdRefOrNull(Record[i]);
829 assert(MD && "Invalid metadata: expect fwd ref to MDNode")((void)0);
830 NMD->addOperand(MD);
831 }
832 break;
833 }
834 case bitc::METADATA_GLOBAL_DECL_ATTACHMENT: {
835 if (!GlobalDeclAttachmentPos)
836 GlobalDeclAttachmentPos = SavedPos;
837#ifndef NDEBUG1
838 NumGlobalDeclAttachSkipped++;
839#endif
840 break;
841 }
842 case bitc::METADATA_KIND:
843 case bitc::METADATA_STRING_OLD:
844 case bitc::METADATA_OLD_FN_NODE:
845 case bitc::METADATA_OLD_NODE:
846 case bitc::METADATA_VALUE:
847 case bitc::METADATA_DISTINCT_NODE:
848 case bitc::METADATA_NODE:
849 case bitc::METADATA_LOCATION:
850 case bitc::METADATA_GENERIC_DEBUG:
851 case bitc::METADATA_SUBRANGE:
852 case bitc::METADATA_ENUMERATOR:
853 case bitc::METADATA_BASIC_TYPE:
854 case bitc::METADATA_STRING_TYPE:
855 case bitc::METADATA_DERIVED_TYPE:
856 case bitc::METADATA_COMPOSITE_TYPE:
857 case bitc::METADATA_SUBROUTINE_TYPE:
858 case bitc::METADATA_MODULE:
859 case bitc::METADATA_FILE:
860 case bitc::METADATA_COMPILE_UNIT:
861 case bitc::METADATA_SUBPROGRAM:
862 case bitc::METADATA_LEXICAL_BLOCK:
863 case bitc::METADATA_LEXICAL_BLOCK_FILE:
864 case bitc::METADATA_NAMESPACE:
865 case bitc::METADATA_COMMON_BLOCK:
866 case bitc::METADATA_MACRO:
867 case bitc::METADATA_MACRO_FILE:
868 case bitc::METADATA_TEMPLATE_TYPE:
869 case bitc::METADATA_TEMPLATE_VALUE:
870 case bitc::METADATA_GLOBAL_VAR:
871 case bitc::METADATA_LOCAL_VAR:
872 case bitc::METADATA_LABEL:
873 case bitc::METADATA_EXPRESSION:
874 case bitc::METADATA_OBJC_PROPERTY:
875 case bitc::METADATA_IMPORTED_ENTITY:
876 case bitc::METADATA_GLOBAL_VAR_EXPR:
877 case bitc::METADATA_GENERIC_SUBRANGE:
878 // We don't expect to see any of these, if we see one, give up on
879 // lazy-loading and fallback.
880 MDStringRef.clear();
881 GlobalMetadataBitPosIndex.clear();
882 return false;
883 }
884 break;
885 }
886 }
887 }
888}
889
890// Load the global decl attachments after building the lazy loading index.
891// We don't load them "lazily" - all global decl attachments must be
892// parsed since they aren't materialized on demand. However, by delaying
893// their parsing until after the index is created, we can use the index
894// instead of creating temporaries.
895Expected<bool> MetadataLoader::MetadataLoaderImpl::loadGlobalDeclAttachments() {
896 // Nothing to do if we didn't find any of these metadata records.
897 if (!GlobalDeclAttachmentPos)
898 return true;
899 // Use a temporary cursor so that we don't mess up the main Stream cursor or
900 // the lazy loading IndexCursor (which holds the necessary abbrev ids).
901 BitstreamCursor TempCursor = Stream;
902 SmallVector<uint64_t, 64> Record;
903 // Jump to the position before the first global decl attachment, so we can
904 // scan for the first BitstreamEntry record.
905 if (Error Err = TempCursor.JumpToBit(GlobalDeclAttachmentPos))
906 return std::move(Err);
907 while (true) {
908 Expected<BitstreamEntry> MaybeEntry = TempCursor.advanceSkippingSubblocks(
909 BitstreamCursor::AF_DontPopBlockAtEnd);
910 if (!MaybeEntry)
911 return MaybeEntry.takeError();
912 BitstreamEntry Entry = MaybeEntry.get();
913
914 switch (Entry.Kind) {
915 case BitstreamEntry::SubBlock: // Handled for us already.
916 case BitstreamEntry::Error:
917 return error("Malformed block");
918 case BitstreamEntry::EndBlock:
919 // Sanity check that we parsed them all.
920 assert(NumGlobalDeclAttachSkipped == NumGlobalDeclAttachParsed)((void)0);
921 return true;
922 case BitstreamEntry::Record:
923 break;
924 }
925 uint64_t CurrentPos = TempCursor.GetCurrentBitNo();
926 Expected<unsigned> MaybeCode = TempCursor.skipRecord(Entry.ID);
927 if (!MaybeCode)
928 return MaybeCode.takeError();
929 if (MaybeCode.get() != bitc::METADATA_GLOBAL_DECL_ATTACHMENT) {
930 // Anything other than a global decl attachment signals the end of
931 // these records. sanity check that we parsed them all.
932 assert(NumGlobalDeclAttachSkipped == NumGlobalDeclAttachParsed)((void)0);
933 return true;
934 }
935#ifndef NDEBUG1
936 NumGlobalDeclAttachParsed++;
937#endif
938 // FIXME: we need to do this early because we don't materialize global
939 // value explicitly.
940 if (Error Err = TempCursor.JumpToBit(CurrentPos))
941 return std::move(Err);
942 Record.clear();
943 if (Expected<unsigned> MaybeRecord =
944 TempCursor.readRecord(Entry.ID, Record))
945 ;
946 else
947 return MaybeRecord.takeError();
948 if (Record.size() % 2 == 0)
949 return error("Invalid record");
950 unsigned ValueID = Record[0];
951 if (ValueID >= ValueList.size())
952 return error("Invalid record");
953 if (auto *GO = dyn_cast<GlobalObject>(ValueList[ValueID])) {
954 // Need to save and restore the current position since
955 // parseGlobalObjectAttachment will resolve all forward references which
956 // would require parsing from locations stored in the index.
957 CurrentPos = TempCursor.GetCurrentBitNo();
958 if (Error Err = parseGlobalObjectAttachment(
959 *GO, ArrayRef<uint64_t>(Record).slice(1)))
960 return std::move(Err);
961 if (Error Err = TempCursor.JumpToBit(CurrentPos))
962 return std::move(Err);
963 }
964 }
965}
966
967/// Parse a METADATA_BLOCK. If ModuleLevel is true then we are parsing
968/// module level metadata.
969Error MetadataLoader::MetadataLoaderImpl::parseMetadata(bool ModuleLevel) {
970 if (!ModuleLevel && MetadataList.hasFwdRefs())
971 return error("Invalid metadata: fwd refs into function blocks");
972
973 // Record the entry position so that we can jump back here and efficiently
974 // skip the whole block in case we lazy-load.
975 auto EntryPos = Stream.GetCurrentBitNo();
976
977 if (Error Err = Stream.EnterSubBlock(bitc::METADATA_BLOCK_ID))
978 return Err;
979
980 SmallVector<uint64_t, 64> Record;
981 PlaceholderQueue Placeholders;
982
983 // We lazy-load module-level metadata: we build an index for each record, and
984 // then load individual record as needed, starting with the named metadata.
985 if (ModuleLevel && IsImporting && MetadataList.empty() &&
986 !DisableLazyLoading) {
987 auto SuccessOrErr = lazyLoadModuleMetadataBlock();
988 if (!SuccessOrErr)
989 return SuccessOrErr.takeError();
990 if (SuccessOrErr.get()) {
991 // An index was successfully created and we will be able to load metadata
992 // on-demand.
993 MetadataList.resize(MDStringRef.size() +
994 GlobalMetadataBitPosIndex.size());
995
996 // Now that we have built the index, load the global decl attachments
997 // that were deferred during that process. This avoids creating
998 // temporaries.
999 SuccessOrErr = loadGlobalDeclAttachments();
1000 if (!SuccessOrErr)
1001 return SuccessOrErr.takeError();
1002 assert(SuccessOrErr.get())((void)0);
1003
1004 // Reading the named metadata created forward references and/or
1005 // placeholders, that we flush here.
1006 resolveForwardRefsAndPlaceholders(Placeholders);
1007 upgradeDebugInfo();
1008 // Return at the beginning of the block, since it is easy to skip it
1009 // entirely from there.
1010 Stream.ReadBlockEnd(); // Pop the abbrev block context.
1011 if (Error Err = IndexCursor.JumpToBit(EntryPos))
1012 return Err;
1013 if (Error Err = Stream.SkipBlock()) {
1014 // FIXME this drops the error on the floor, which
1015 // ThinLTO/X86/debuginfo-cu-import.ll relies on.
1016 consumeError(std::move(Err));
1017 return Error::success();
1018 }
1019 return Error::success();
1020 }
1021 // Couldn't load an index, fallback to loading all the block "old-style".
1022 }
1023
1024 unsigned NextMetadataNo = MetadataList.size();
1025
1026 // Read all the records.
1027 while (true) {
1028 Expected<BitstreamEntry> MaybeEntry = Stream.advanceSkippingSubblocks();
1029 if (!MaybeEntry)
1030 return MaybeEntry.takeError();
1031 BitstreamEntry Entry = MaybeEntry.get();
1032
1033 switch (Entry.Kind) {
1034 case BitstreamEntry::SubBlock: // Handled for us already.
1035 case BitstreamEntry::Error:
1036 return error("Malformed block");
1037 case BitstreamEntry::EndBlock:
1038 resolveForwardRefsAndPlaceholders(Placeholders);
1039 upgradeDebugInfo();
1040 return Error::success();
1041 case BitstreamEntry::Record:
1042 // The interesting case.
1043 break;
1044 }
1045
1046 // Read a record.
1047 Record.clear();
1048 StringRef Blob;
1049 ++NumMDRecordLoaded;
1050 if (Expected<unsigned> MaybeCode =
1051 Stream.readRecord(Entry.ID, Record, &Blob)) {
1052 if (Error Err = parseOneMetadata(Record, MaybeCode.get(), Placeholders,
1053 Blob, NextMetadataNo))
1054 return Err;
1055 } else
1056 return MaybeCode.takeError();
1057 }
1058}
1059
1060MDString *MetadataLoader::MetadataLoaderImpl::lazyLoadOneMDString(unsigned ID) {
1061 ++NumMDStringLoaded;
1062 if (Metadata *MD = MetadataList.lookup(ID))
1063 return cast<MDString>(MD);
1064 auto MDS = MDString::get(Context, MDStringRef[ID]);
1065 MetadataList.assignValue(MDS, ID);
1066 return MDS;
1067}
1068
1069void MetadataLoader::MetadataLoaderImpl::lazyLoadOneMetadata(
1070 unsigned ID, PlaceholderQueue &Placeholders) {
1071 assert(ID < (MDStringRef.size()) + GlobalMetadataBitPosIndex.size())((void)0);
1072 assert(ID >= MDStringRef.size() && "Unexpected lazy-loading of MDString")((void)0);
1073 // Lookup first if the metadata hasn't already been loaded.
1074 if (auto *MD = MetadataList.lookup(ID)) {
1075 auto *N = cast<MDNode>(MD);
1076 if (!N->isTemporary())
1077 return;
1078 }
1079 SmallVector<uint64_t, 64> Record;
1080 StringRef Blob;
1081 if (Error Err = IndexCursor.JumpToBit(
1082 GlobalMetadataBitPosIndex[ID - MDStringRef.size()]))
1083 report_fatal_error("lazyLoadOneMetadata failed jumping: " +
1084 toString(std::move(Err)));
1085 Expected<BitstreamEntry> MaybeEntry = IndexCursor.advanceSkippingSubblocks();
1086 if (!MaybeEntry)
1087 // FIXME this drops the error on the floor.
1088 report_fatal_error("lazyLoadOneMetadata failed advanceSkippingSubblocks: " +
1089 toString(MaybeEntry.takeError()));
1090 BitstreamEntry Entry = MaybeEntry.get();
1091 ++NumMDRecordLoaded;
1092 if (Expected<unsigned> MaybeCode =
1093 IndexCursor.readRecord(Entry.ID, Record, &Blob)) {
1094 if (Error Err =
1095 parseOneMetadata(Record, MaybeCode.get(), Placeholders, Blob, ID))
1096 report_fatal_error("Can't lazyload MD, parseOneMetadata: " +
1097 toString(std::move(Err)));
1098 } else
1099 report_fatal_error("Can't lazyload MD: " + toString(MaybeCode.takeError()));
1100}
1101
1102/// Ensure that all forward-references and placeholders are resolved.
1103/// Iteratively lazy-loading metadata on-demand if needed.
1104void MetadataLoader::MetadataLoaderImpl::resolveForwardRefsAndPlaceholders(
1105 PlaceholderQueue &Placeholders) {
1106 DenseSet<unsigned> Temporaries;
1107 while (1) {
1108 // Populate Temporaries with the placeholders that haven't been loaded yet.
1109 Placeholders.getTemporaries(MetadataList, Temporaries);
1110
1111 // If we don't have any temporary, or FwdReference, we're done!
1112 if (Temporaries.empty() && !MetadataList.hasFwdRefs())
1113 break;
1114
1115 // First, load all the temporaries. This can add new placeholders or
1116 // forward references.
1117 for (auto ID : Temporaries)
1118 lazyLoadOneMetadata(ID, Placeholders);
1119 Temporaries.clear();
1120
1121 // Second, load the forward-references. This can also add new placeholders
1122 // or forward references.
1123 while (MetadataList.hasFwdRefs())
1124 lazyLoadOneMetadata(MetadataList.getNextFwdRef(), Placeholders);
1125 }
1126 // At this point we don't have any forward reference remaining, or temporary
1127 // that haven't been loaded. We can safely drop RAUW support and mark cycles
1128 // as resolved.
1129 MetadataList.tryToResolveCycles();
1130
1131 // Finally, everything is in place, we can replace the placeholders operands
1132 // with the final node they refer to.
1133 Placeholders.flush(MetadataList);
1134}
1135
1136Error MetadataLoader::MetadataLoaderImpl::parseOneMetadata(
1137 SmallVectorImpl<uint64_t> &Record, unsigned Code,
1138 PlaceholderQueue &Placeholders, StringRef Blob, unsigned &NextMetadataNo) {
1139
1140 bool IsDistinct = false;
1141 auto getMD = [&](unsigned ID) -> Metadata * {
1142 if (ID < MDStringRef.size())
1143 return lazyLoadOneMDString(ID);
1144 if (!IsDistinct) {
1145 if (auto *MD = MetadataList.lookup(ID))
1146 return MD;
1147 // If lazy-loading is enabled, we try recursively to load the operand
1148 // instead of creating a temporary.
1149 if (ID < (MDStringRef.size() + GlobalMetadataBitPosIndex.size())) {
1150 // Create a temporary for the node that is referencing the operand we
1151 // will lazy-load. It is needed before recursing in case there are
1152 // uniquing cycles.
1153 MetadataList.getMetadataFwdRef(NextMetadataNo);
1154 lazyLoadOneMetadata(ID, Placeholders);
1155 return MetadataList.lookup(ID);
1156 }
1157 // Return a temporary.
1158 return MetadataList.getMetadataFwdRef(ID);
1159 }
1160 if (auto *MD = MetadataList.getMetadataIfResolved(ID))
1161 return MD;
1162 return &Placeholders.getPlaceholderOp(ID);
1163 };
1164 auto getMDOrNull = [&](unsigned ID) -> Metadata * {
1165 if (ID)
1166 return getMD(ID - 1);
1167 return nullptr;
1168 };
1169 auto getMDOrNullWithoutPlaceholders = [&](unsigned ID) -> Metadata * {
1170 if (ID)
1171 return MetadataList.getMetadataFwdRef(ID - 1);
1172 return nullptr;
1173 };
1174 auto getMDString = [&](unsigned ID) -> MDString * {
1175 // This requires that the ID is not really a forward reference. In
1176 // particular, the MDString must already have been resolved.
1177 auto MDS = getMDOrNull(ID);
1178 return cast_or_null<MDString>(MDS);
1179 };
1180
1181 // Support for old type refs.
1182 auto getDITypeRefOrNull = [&](unsigned ID) {
1183 return MetadataList.upgradeTypeRef(getMDOrNull(ID));
1184 };
1185
1186#define GET_OR_DISTINCT(CLASS, ARGS) \
1187 (IsDistinct ? CLASS::getDistinct ARGS : CLASS::get ARGS)
1188
1189 switch (Code) {
1190 default: // Default behavior: ignore.
1191 break;
1192 case bitc::METADATA_NAME: {
1193 // Read name of the named metadata.
1194 SmallString<8> Name(Record.begin(), Record.end());
1195 Record.clear();
1196 Expected<unsigned> MaybeCode = Stream.ReadCode();
1197 if (!MaybeCode)
1198 return MaybeCode.takeError();
1199 Code = MaybeCode.get();
1200
1201 ++NumMDRecordLoaded;
1202 if (Expected<unsigned> MaybeNextBitCode = Stream.readRecord(Code, Record)) {
1203 if (MaybeNextBitCode.get() != bitc::METADATA_NAMED_NODE)
1204 return error("METADATA_NAME not followed by METADATA_NAMED_NODE");
1205 } else
1206 return MaybeNextBitCode.takeError();
1207
1208 // Read named metadata elements.
1209 unsigned Size = Record.size();
1210 NamedMDNode *NMD = TheModule.getOrInsertNamedMetadata(Name);
1211 for (unsigned i = 0; i != Size; ++i) {
1212 MDNode *MD = MetadataList.getMDNodeFwdRefOrNull(Record[i]);
1213 if (!MD)
1214 return error("Invalid named metadata: expect fwd ref to MDNode");
1215 NMD->addOperand(MD);
1216 }
1217 break;
1218 }
1219 case bitc::METADATA_OLD_FN_NODE: {
1220 // Deprecated, but still needed to read old bitcode files.
1221 // This is a LocalAsMetadata record, the only type of function-local
1222 // metadata.
1223 if (Record.size() % 2 == 1)
1224 return error("Invalid record");
1225
1226 // If this isn't a LocalAsMetadata record, we're dropping it. This used
1227 // to be legal, but there's no upgrade path.
1228 auto dropRecord = [&] {
1229 MetadataList.assignValue(MDNode::get(Context, None), NextMetadataNo);
1230 NextMetadataNo++;
1231 };
1232 if (Record.size() != 2) {
1233 dropRecord();
1234 break;
1235 }
1236
1237 Type *Ty = getTypeByID(Record[0]);
1238 if (Ty->isMetadataTy() || Ty->isVoidTy()) {
1239 dropRecord();
1240 break;
1241 }
1242
1243 MetadataList.assignValue(
1244 LocalAsMetadata::get(ValueList.getValueFwdRef(Record[1], Ty)),
1245 NextMetadataNo);
1246 NextMetadataNo++;
1247 break;
1248 }
1249 case bitc::METADATA_OLD_NODE: {
1250 // Deprecated, but still needed to read old bitcode files.
1251 if (Record.size() % 2 == 1)
1252 return error("Invalid record");
1253
1254 unsigned Size = Record.size();
1255 SmallVector<Metadata *, 8> Elts;
1256 for (unsigned i = 0; i != Size; i += 2) {
1257 Type *Ty = getTypeByID(Record[i]);
1258 if (!Ty)
1259 return error("Invalid record");
1260 if (Ty->isMetadataTy())
1261 Elts.push_back(getMD(Record[i + 1]));
1262 else if (!Ty->isVoidTy()) {
1263 auto *MD =
1264 ValueAsMetadata::get(ValueList.getValueFwdRef(Record[i + 1], Ty));
1265 assert(isa<ConstantAsMetadata>(MD) &&((void)0)
1266 "Expected non-function-local metadata")((void)0);
1267 Elts.push_back(MD);
1268 } else
1269 Elts.push_back(nullptr);
1270 }
1271 MetadataList.assignValue(MDNode::get(Context, Elts), NextMetadataNo);
1272 NextMetadataNo++;
1273 break;
1274 }
1275 case bitc::METADATA_VALUE: {
1276 if (Record.size() != 2)
1277 return error("Invalid record");
1278
1279 Type *Ty = getTypeByID(Record[0]);
1280 if (Ty->isMetadataTy() || Ty->isVoidTy())
1281 return error("Invalid record");
1282
1283 MetadataList.assignValue(
1284 ValueAsMetadata::get(ValueList.getValueFwdRef(Record[1], Ty)),
1285 NextMetadataNo);
1286 NextMetadataNo++;
1287 break;
1288 }
1289 case bitc::METADATA_DISTINCT_NODE:
1290 IsDistinct = true;
1291 LLVM_FALLTHROUGH[[gnu::fallthrough]];
1292 case bitc::METADATA_NODE: {
1293 SmallVector<Metadata *, 8> Elts;
1294 Elts.reserve(Record.size());
1295 for (unsigned ID : Record)
1296 Elts.push_back(getMDOrNull(ID));
1297 MetadataList.assignValue(IsDistinct ? MDNode::getDistinct(Context, Elts)
1298 : MDNode::get(Context, Elts),
1299 NextMetadataNo);
1300 NextMetadataNo++;
1301 break;
1302 }
1303 case bitc::METADATA_LOCATION: {
1304 if (Record.size() != 5 && Record.size() != 6)
1305 return error("Invalid record");
1306
1307 IsDistinct = Record[0];
1308 unsigned Line = Record[1];
1309 unsigned Column = Record[2];
1310 Metadata *Scope = getMD(Record[3]);
1311 Metadata *InlinedAt = getMDOrNull(Record[4]);
1312 bool ImplicitCode = Record.size() == 6 && Record[5];
1313 MetadataList.assignValue(
1314 GET_OR_DISTINCT(DILocation, (Context, Line, Column, Scope, InlinedAt,
1315 ImplicitCode)),
1316 NextMetadataNo);
1317 NextMetadataNo++;
1318 break;
1319 }
1320 case bitc::METADATA_GENERIC_DEBUG: {
1321 if (Record.size() < 4)
1322 return error("Invalid record");
1323
1324 IsDistinct = Record[0];
1325 unsigned Tag = Record[1];
1326 unsigned Version = Record[2];
1327
1328 if (Tag >= 1u << 16 || Version != 0)
1329 return error("Invalid record");
1330
1331 auto *Header = getMDString(Record[3]);
1332 SmallVector<Metadata *, 8> DwarfOps;
1333 for (unsigned I = 4, E = Record.size(); I != E; ++I)
1334 DwarfOps.push_back(getMDOrNull(Record[I]));
1335 MetadataList.assignValue(
1336 GET_OR_DISTINCT(GenericDINode, (Context, Tag, Header, DwarfOps)),
1337 NextMetadataNo);
1338 NextMetadataNo++;
1339 break;
1340 }
1341 case bitc::METADATA_SUBRANGE: {
1342 Metadata *Val = nullptr;
1343 // Operand 'count' is interpreted as:
1344 // - Signed integer (version 0)
1345 // - Metadata node (version 1)
1346 // Operand 'lowerBound' is interpreted as:
1347 // - Signed integer (version 0 and 1)
1348 // - Metadata node (version 2)
1349 // Operands 'upperBound' and 'stride' are interpreted as:
1350 // - Metadata node (version 2)
1351 switch (Record[0] >> 1) {
1352 case 0:
1353 Val = GET_OR_DISTINCT(DISubrange,
1354 (Context, Record[1], unrotateSign(Record[2])));
1355 break;
1356 case 1:
1357 Val = GET_OR_DISTINCT(DISubrange, (Context, getMDOrNull(Record[1]),
1358 unrotateSign(Record[2])));
1359 break;
1360 case 2:
1361 Val = GET_OR_DISTINCT(
1362 DISubrange, (Context, getMDOrNull(Record[1]), getMDOrNull(Record[2]),
1363 getMDOrNull(Record[3]), getMDOrNull(Record[4])));
1364 break;
1365 default:
1366 return error("Invalid record: Unsupported version of DISubrange");
1367 }
1368
1369 MetadataList.assignValue(Val, NextMetadataNo);
1370 IsDistinct = Record[0] & 1;
1371 NextMetadataNo++;
1372 break;
1373 }
1374 case bitc::METADATA_GENERIC_SUBRANGE: {
1375 Metadata *Val = nullptr;
1376 Val = GET_OR_DISTINCT(DIGenericSubrange,
1377 (Context, getMDOrNull(Record[1]),
1378 getMDOrNull(Record[2]), getMDOrNull(Record[3]),
1379 getMDOrNull(Record[4])));
1380
1381 MetadataList.assignValue(Val, NextMetadataNo);
1382 IsDistinct = Record[0] & 1;
1383 NextMetadataNo++;
1384 break;
1385 }
1386 case bitc::METADATA_ENUMERATOR: {
1387 if (Record.size() < 3)
1388 return error("Invalid record");
1389
1390 IsDistinct = Record[0] & 1;
1391 bool IsUnsigned = Record[0] & 2;
1392 bool IsBigInt = Record[0] & 4;
1393 APInt Value;
1394
1395 if (IsBigInt) {
1396 const uint64_t BitWidth = Record[1];
1397 const size_t NumWords = Record.size() - 3;
1398 Value = readWideAPInt(makeArrayRef(&Record[3], NumWords), BitWidth);
1399 } else
1400 Value = APInt(64, unrotateSign(Record[1]), !IsUnsigned);
1401
1402 MetadataList.assignValue(
1403 GET_OR_DISTINCT(DIEnumerator,
1404 (Context, Value, IsUnsigned, getMDString(Record[2]))),
1405 NextMetadataNo);
1406 NextMetadataNo++;
1407 break;
1408 }
1409 case bitc::METADATA_BASIC_TYPE: {
1410 if (Record.size() < 6 || Record.size() > 7)
1411 return error("Invalid record");
1412
1413 IsDistinct = Record[0];
1414 DINode::DIFlags Flags = (Record.size() > 6) ?
1415 static_cast<DINode::DIFlags>(Record[6]) : DINode::FlagZero;
1416
1417 MetadataList.assignValue(
1418 GET_OR_DISTINCT(DIBasicType,
1419 (Context, Record[1], getMDString(Record[2]), Record[3],
1420 Record[4], Record[5], Flags)),
1421 NextMetadataNo);
1422 NextMetadataNo++;
1423 break;
1424 }
1425 case bitc::METADATA_STRING_TYPE: {
1426 if (Record.size() != 8)
1427 return error("Invalid record");
1428
1429 IsDistinct = Record[0];
1430 MetadataList.assignValue(
1431 GET_OR_DISTINCT(DIStringType,
1432 (Context, Record[1], getMDString(Record[2]),
1433 getMDOrNull(Record[3]), getMDOrNull(Record[4]),
1434 Record[5], Record[6], Record[7])),
1435 NextMetadataNo);
1436 NextMetadataNo++;
1437 break;
1438 }
1439 case bitc::METADATA_DERIVED_TYPE: {
1440 if (Record.size() < 12 || Record.size() > 13)
1441 return error("Invalid record");
1442
1443 // DWARF address space is encoded as N->getDWARFAddressSpace() + 1. 0 means
1444 // that there is no DWARF address space associated with DIDerivedType.
1445 Optional<unsigned> DWARFAddressSpace;
1446 if (Record.size() > 12 && Record[12])
1447 DWARFAddressSpace = Record[12] - 1;
1448
1449 IsDistinct = Record[0];
1450 DINode::DIFlags Flags = static_cast<DINode::DIFlags>(Record[10]);
1451 MetadataList.assignValue(
1452 GET_OR_DISTINCT(DIDerivedType,
1453 (Context, Record[1], getMDString(Record[2]),
1454 getMDOrNull(Record[3]), Record[4],
1455 getDITypeRefOrNull(Record[5]),
1456 getDITypeRefOrNull(Record[6]), Record[7], Record[8],
1457 Record[9], DWARFAddressSpace, Flags,
1458 getDITypeRefOrNull(Record[11]))),
1459 NextMetadataNo);
1460 NextMetadataNo++;
1461 break;
1462 }
1463 case bitc::METADATA_COMPOSITE_TYPE: {
1464 if (Record.size() < 16 || Record.size() > 21)
1465 return error("Invalid record");
1466
1467 // If we have a UUID and this is not a forward declaration, lookup the
1468 // mapping.
1469 IsDistinct = Record[0] & 0x1;
1470 bool IsNotUsedInTypeRef = Record[0] >= 2;
1471 unsigned Tag = Record[1];
1472 MDString *Name = getMDString(Record[2]);
1473 Metadata *File = getMDOrNull(Record[3]);
1474 unsigned Line = Record[4];
1475 Metadata *Scope = getDITypeRefOrNull(Record[5]);
1476 Metadata *BaseType = nullptr;
1477 uint64_t SizeInBits = Record[7];
1478 if (Record[8] > (uint64_t)std::numeric_limits<uint32_t>::max())
1479 return error("Alignment value is too large");
1480 uint32_t AlignInBits = Record[8];
1481 uint64_t OffsetInBits = 0;
1482 DINode::DIFlags Flags = static_cast<DINode::DIFlags>(Record[10]);
1483 Metadata *Elements = nullptr;
1484 unsigned RuntimeLang = Record[12];
1485 Metadata *VTableHolder = nullptr;
1486 Metadata *TemplateParams = nullptr;
1487 Metadata *Discriminator = nullptr;
1488 Metadata *DataLocation = nullptr;
1489 Metadata *Associated = nullptr;
1490 Metadata *Allocated = nullptr;
1491 Metadata *Rank = nullptr;
1492 auto *Identifier = getMDString(Record[15]);
1493 // If this module is being parsed so that it can be ThinLTO imported
1494 // into another module, composite types only need to be imported
1495 // as type declarations (unless full type definitions requested).
1496 // Create type declarations up front to save memory. Also, buildODRType
1497 // handles the case where this is type ODRed with a definition needed
1498 // by the importing module, in which case the existing definition is
1499 // used.
1500 if (IsImporting && !ImportFullTypeDefinitions && Identifier &&
1501 (Tag == dwarf::DW_TAG_enumeration_type ||
1502 Tag == dwarf::DW_TAG_class_type ||
1503 Tag == dwarf::DW_TAG_structure_type ||
1504 Tag == dwarf::DW_TAG_union_type)) {
1505 Flags = Flags | DINode::FlagFwdDecl;
1506 } else {
1507 BaseType = getDITypeRefOrNull(Record[6]);
1508 OffsetInBits = Record[9];
1509 Elements = getMDOrNull(Record[11]);
1510 VTableHolder = getDITypeRefOrNull(Record[13]);
1511 TemplateParams = getMDOrNull(Record[14]);
1512 if (Record.size() > 16)
1513 Discriminator = getMDOrNull(Record[16]);
1514 if (Record.size() > 17)
1515 DataLocation = getMDOrNull(Record[17]);
1516 if (Record.size() > 19) {
1517 Associated = getMDOrNull(Record[18]);
1518 Allocated = getMDOrNull(Record[19]);
1519 }
1520 if (Record.size() > 20) {
1521 Rank = getMDOrNull(Record[20]);
1522 }
1523 }
1524 DICompositeType *CT = nullptr;
1525 if (Identifier)
1526 CT = DICompositeType::buildODRType(
1527 Context, *Identifier, Tag, Name, File, Line, Scope, BaseType,
1528 SizeInBits, AlignInBits, OffsetInBits, Flags, Elements, RuntimeLang,
1529 VTableHolder, TemplateParams, Discriminator, DataLocation, Associated,
1530 Allocated, Rank);
1531
1532 // Create a node if we didn't get a lazy ODR type.
1533 if (!CT)
1534 CT = GET_OR_DISTINCT(DICompositeType,
1535 (Context, Tag, Name, File, Line, Scope, BaseType,
1536 SizeInBits, AlignInBits, OffsetInBits, Flags,
1537 Elements, RuntimeLang, VTableHolder, TemplateParams,
1538 Identifier, Discriminator, DataLocation, Associated,
1539 Allocated, Rank));
1540 if (!IsNotUsedInTypeRef && Identifier)
1541 MetadataList.addTypeRef(*Identifier, *cast<DICompositeType>(CT));
1542
1543 MetadataList.assignValue(CT, NextMetadataNo);
1544 NextMetadataNo++;
1545 break;
1546 }
1547 case bitc::METADATA_SUBROUTINE_TYPE: {
1548 if (Record.size() < 3 || Record.size() > 4)
1549 return error("Invalid record");
1550 bool IsOldTypeRefArray = Record[0] < 2;
1551 unsigned CC = (Record.size() > 3) ? Record[3] : 0;
1552
1553 IsDistinct = Record[0] & 0x1;
1554 DINode::DIFlags Flags = static_cast<DINode::DIFlags>(Record[1]);
1555 Metadata *Types = getMDOrNull(Record[2]);
1556 if (LLVM_UNLIKELY(IsOldTypeRefArray)__builtin_expect((bool)(IsOldTypeRefArray), false))
1557 Types = MetadataList.upgradeTypeRefArray(Types);
1558
1559 MetadataList.assignValue(
1560 GET_OR_DISTINCT(DISubroutineType, (Context, Flags, CC, Types)),
1561 NextMetadataNo);
1562 NextMetadataNo++;
1563 break;
1564 }
1565
1566 case bitc::METADATA_MODULE: {
1567 if (Record.size() < 5 || Record.size() > 9)
1568 return error("Invalid record");
1569
1570 unsigned Offset = Record.size() >= 8 ? 2 : 1;
1571 IsDistinct = Record[0];
1572 MetadataList.assignValue(
1573 GET_OR_DISTINCT(
1574 DIModule,
1575 (Context, Record.size() >= 8 ? getMDOrNull(Record[1]) : nullptr,
1576 getMDOrNull(Record[0 + Offset]), getMDString(Record[1 + Offset]),
1577 getMDString(Record[2 + Offset]), getMDString(Record[3 + Offset]),
1578 getMDString(Record[4 + Offset]),
1579 Record.size() <= 7 ? 0 : Record[7],
1580 Record.size() <= 8 ? false : Record[8])),
1581 NextMetadataNo);
1582 NextMetadataNo++;
1583 break;
1584 }
1585
1586 case bitc::METADATA_FILE: {
1587 if (Record.size() != 3 && Record.size() != 5 && Record.size() != 6)
1588 return error("Invalid record");
1589
1590 IsDistinct = Record[0];
1591 Optional<DIFile::ChecksumInfo<MDString *>> Checksum;
1592 // The BitcodeWriter writes null bytes into Record[3:4] when the Checksum
1593 // is not present. This matches up with the old internal representation,
1594 // and the old encoding for CSK_None in the ChecksumKind. The new
1595 // representation reserves the value 0 in the ChecksumKind to continue to
1596 // encode None in a backwards-compatible way.
1597 if (Record.size() > 4 && Record[3] && Record[4])
1598 Checksum.emplace(static_cast<DIFile::ChecksumKind>(Record[3]),
1599 getMDString(Record[4]));
1600 MetadataList.assignValue(
1601 GET_OR_DISTINCT(
1602 DIFile,
1603 (Context, getMDString(Record[1]), getMDString(Record[2]), Checksum,
1604 Record.size() > 5 ? Optional<MDString *>(getMDString(Record[5]))
1605 : None)),
1606 NextMetadataNo);
1607 NextMetadataNo++;
1608 break;
1609 }
1610 case bitc::METADATA_COMPILE_UNIT: {
1611 if (Record.size() < 14 || Record.size() > 22)
1612 return error("Invalid record");
1613
1614 // Ignore Record[0], which indicates whether this compile unit is
1615 // distinct. It's always distinct.
1616 IsDistinct = true;
1617 auto *CU = DICompileUnit::getDistinct(
1618 Context, Record[1], getMDOrNull(Record[2]), getMDString(Record[3]),
1619 Record[4], getMDString(Record[5]), Record[6], getMDString(Record[7]),
1620 Record[8], getMDOrNull(Record[9]), getMDOrNull(Record[10]),
1621 getMDOrNull(Record[12]), getMDOrNull(Record[13]),
1622 Record.size() <= 15 ? nullptr : getMDOrNull(Record[15]),
1623 Record.size() <= 14 ? 0 : Record[14],
1624 Record.size() <= 16 ? true : Record[16],
1625 Record.size() <= 17 ? false : Record[17],
1626 Record.size() <= 18 ? 0 : Record[18],
1627 Record.size() <= 19 ? 0 : Record[19],
1628 Record.size() <= 20 ? nullptr : getMDString(Record[20]),
1629 Record.size() <= 21 ? nullptr : getMDString(Record[21]));
1630
1631 MetadataList.assignValue(CU, NextMetadataNo);
1632 NextMetadataNo++;
1633
1634 // Move the Upgrade the list of subprograms.
1635 if (Metadata *SPs = getMDOrNullWithoutPlaceholders(Record[11]))
1636 CUSubprograms.push_back({CU, SPs});
1637 break;
1638 }
1639 case bitc::METADATA_SUBPROGRAM: {
1640 if (Record.size() < 18 || Record.size() > 21)
1641 return error("Invalid record");
1642
1643 bool HasSPFlags = Record[0] & 4;
1644
1645 DINode::DIFlags Flags;
1646 DISubprogram::DISPFlags SPFlags;
1647 if (!HasSPFlags)
1648 Flags = static_cast<DINode::DIFlags>(Record[11 + 2]);
1649 else {
1650 Flags = static_cast<DINode::DIFlags>(Record[11]);
1651 SPFlags = static_cast<DISubprogram::DISPFlags>(Record[9]);
1652 }
1653
1654 // Support for old metadata when
1655 // subprogram specific flags are placed in DIFlags.
1656 const unsigned DIFlagMainSubprogram = 1 << 21;
1657 bool HasOldMainSubprogramFlag = Flags & DIFlagMainSubprogram;
1658 if (HasOldMainSubprogramFlag)
1659 // Remove old DIFlagMainSubprogram from DIFlags.
1660 // Note: This assumes that any future use of bit 21 defaults to it
1661 // being 0.
1662 Flags &= ~static_cast<DINode::DIFlags>(DIFlagMainSubprogram);
1663
1664 if (HasOldMainSubprogramFlag && HasSPFlags)
1665 SPFlags |= DISubprogram::SPFlagMainSubprogram;
1666 else if (!HasSPFlags)
1667 SPFlags = DISubprogram::toSPFlags(
1668 /*IsLocalToUnit=*/Record[7], /*IsDefinition=*/Record[8],
1669 /*IsOptimized=*/Record[14], /*Virtuality=*/Record[11],
1670 /*DIFlagMainSubprogram*/HasOldMainSubprogramFlag);
1671
1672 // All definitions should be distinct.
1673 IsDistinct = (Record[0] & 1) || (SPFlags & DISubprogram::SPFlagDefinition);
1674 // Version 1 has a Function as Record[15].
1675 // Version 2 has removed Record[15].
1676 // Version 3 has the Unit as Record[15].
1677 // Version 4 added thisAdjustment.
1678 // Version 5 repacked flags into DISPFlags, changing many element numbers.
1679 bool HasUnit = Record[0] & 2;
1680 if (!HasSPFlags && HasUnit && Record.size() < 19)
1681 return error("Invalid record");
1682 if (HasSPFlags && !HasUnit)
1683 return error("Invalid record");
1684 // Accommodate older formats.
1685 bool HasFn = false;
1686 bool HasThisAdj = true;
1687 bool HasThrownTypes = true;
1688 unsigned OffsetA = 0;
1689 unsigned OffsetB = 0;
1690 if (!HasSPFlags) {
1691 OffsetA = 2;
1692 OffsetB = 2;
1693 if (Record.size() >= 19) {
1694 HasFn = !HasUnit;
1695 OffsetB++;
1696 }
1697 HasThisAdj = Record.size() >= 20;
1698 HasThrownTypes = Record.size() >= 21;
1699 }
1700 Metadata *CUorFn = getMDOrNull(Record[12 + OffsetB]);
1701 DISubprogram *SP = GET_OR_DISTINCT(
1702 DISubprogram,
1703 (Context,
1704 getDITypeRefOrNull(Record[1]), // scope
1705 getMDString(Record[2]), // name
1706 getMDString(Record[3]), // linkageName
1707 getMDOrNull(Record[4]), // file
1708 Record[5], // line
1709 getMDOrNull(Record[6]), // type
1710 Record[7 + OffsetA], // scopeLine
1711 getDITypeRefOrNull(Record[8 + OffsetA]), // containingType
1712 Record[10 + OffsetA], // virtualIndex
1713 HasThisAdj ? Record[16 + OffsetB] : 0, // thisAdjustment
1714 Flags, // flags
1715 SPFlags, // SPFlags
1716 HasUnit ? CUorFn : nullptr, // unit
1717 getMDOrNull(Record[13 + OffsetB]), // templateParams
1718 getMDOrNull(Record[14 + OffsetB]), // declaration
1719 getMDOrNull(Record[15 + OffsetB]), // retainedNodes
1720 HasThrownTypes ? getMDOrNull(Record[17 + OffsetB])
1721 : nullptr // thrownTypes
1722 ));
1723 MetadataList.assignValue(SP, NextMetadataNo);
1724 NextMetadataNo++;
1725
1726 // Upgrade sp->function mapping to function->sp mapping.
1727 if (HasFn) {
1728 if (auto *CMD = dyn_cast_or_null<ConstantAsMetadata>(CUorFn))
1729 if (auto *F = dyn_cast<Function>(CMD->getValue())) {
1730 if (F->isMaterializable())
1731 // Defer until materialized; unmaterialized functions may not have
1732 // metadata.
1733 FunctionsWithSPs[F] = SP;
1734 else if (!F->empty())
1735 F->setSubprogram(SP);
1736 }
1737 }
1738 break;
1739 }
1740 case bitc::METADATA_LEXICAL_BLOCK: {
1741 if (Record.size() != 5)
1742 return error("Invalid record");
1743
1744 IsDistinct = Record[0];
1745 MetadataList.assignValue(
1746 GET_OR_DISTINCT(DILexicalBlock,
1747 (Context, getMDOrNull(Record[1]),
1748 getMDOrNull(Record[2]), Record[3], Record[4])),
1749 NextMetadataNo);
1750 NextMetadataNo++;
1751 break;
1752 }
1753 case bitc::METADATA_LEXICAL_BLOCK_FILE: {
1754 if (Record.size() != 4)
1755 return error("Invalid record");
1756
1757 IsDistinct = Record[0];
1758 MetadataList.assignValue(
1759 GET_OR_DISTINCT(DILexicalBlockFile,
1760 (Context, getMDOrNull(Record[1]),
1761 getMDOrNull(Record[2]), Record[3])),
1762 NextMetadataNo);
1763 NextMetadataNo++;
1764 break;
1765 }
1766 case bitc::METADATA_COMMON_BLOCK: {
1767 IsDistinct = Record[0] & 1;
1768 MetadataList.assignValue(
1769 GET_OR_DISTINCT(DICommonBlock,
1770 (Context, getMDOrNull(Record[1]),
1771 getMDOrNull(Record[2]), getMDString(Record[3]),
1772 getMDOrNull(Record[4]), Record[5])),
1773 NextMetadataNo);
1774 NextMetadataNo++;
1775 break;
1776 }
1777 case bitc::METADATA_NAMESPACE: {
1778 // Newer versions of DINamespace dropped file and line.
1779 MDString *Name;
1780 if (Record.size() == 3)
1781 Name = getMDString(Record[2]);
1782 else if (Record.size() == 5)
1783 Name = getMDString(Record[3]);
1784 else
1785 return error("Invalid record");
1786
1787 IsDistinct = Record[0] & 1;
1788 bool ExportSymbols = Record[0] & 2;
1789 MetadataList.assignValue(
1790 GET_OR_DISTINCT(DINamespace,
1791 (Context, getMDOrNull(Record[1]), Name, ExportSymbols)),
1792 NextMetadataNo);
1793 NextMetadataNo++;
1794 break;
1795 }
1796 case bitc::METADATA_MACRO: {
1797 if (Record.size() != 5)
1798 return error("Invalid record");
1799
1800 IsDistinct = Record[0];
1801 MetadataList.assignValue(
1802 GET_OR_DISTINCT(DIMacro,
1803 (Context, Record[1], Record[2], getMDString(Record[3]),
1804 getMDString(Record[4]))),
1805 NextMetadataNo);
1806 NextMetadataNo++;
1807 break;
1808 }
1809 case bitc::METADATA_MACRO_FILE: {
1810 if (Record.size() != 5)
1811 return error("Invalid record");
1812
1813 IsDistinct = Record[0];
1814 MetadataList.assignValue(
1815 GET_OR_DISTINCT(DIMacroFile,
1816 (Context, Record[1], Record[2], getMDOrNull(Record[3]),
1817 getMDOrNull(Record[4]))),
1818 NextMetadataNo);
1819 NextMetadataNo++;
1820 break;
1821 }
1822 case bitc::METADATA_TEMPLATE_TYPE: {
1823 if (Record.size() < 3 || Record.size() > 4)
1824 return error("Invalid record");
1825
1826 IsDistinct = Record[0];
1827 MetadataList.assignValue(
1828 GET_OR_DISTINCT(DITemplateTypeParameter,
1829 (Context, getMDString(Record[1]),
1830 getDITypeRefOrNull(Record[2]),
1831 (Record.size() == 4) ? getMDOrNull(Record[3])
1832 : getMDOrNull(false))),
1833 NextMetadataNo);
1834 NextMetadataNo++;
1835 break;
1836 }
1837 case bitc::METADATA_TEMPLATE_VALUE: {
1838 if (Record.size() < 5 || Record.size() > 6)
1839 return error("Invalid record");
1840
1841 IsDistinct = Record[0];
1842
1843 MetadataList.assignValue(
1844 GET_OR_DISTINCT(
1845 DITemplateValueParameter,
1846 (Context, Record[1], getMDString(Record[2]),
1847 getDITypeRefOrNull(Record[3]),
1848 (Record.size() == 6) ? getMDOrNull(Record[4]) : getMDOrNull(false),
1849 (Record.size() == 6) ? getMDOrNull(Record[5])
1850 : getMDOrNull(Record[4]))),
1851 NextMetadataNo);
1852 NextMetadataNo++;
1853 break;
1854 }
1855 case bitc::METADATA_GLOBAL_VAR: {
1856 if (Record.size() < 11 || Record.size() > 13)
1857 return error("Invalid record");
1858
1859 IsDistinct = Record[0] & 1;
1860 unsigned Version = Record[0] >> 1;
1861
1862 if (Version == 2) {
1863 MetadataList.assignValue(
1864 GET_OR_DISTINCT(
1865 DIGlobalVariable,
1866 (Context, getMDOrNull(Record[1]), getMDString(Record[2]),
1867 getMDString(Record[3]), getMDOrNull(Record[4]), Record[5],
1868 getDITypeRefOrNull(Record[6]), Record[7], Record[8],
1869 getMDOrNull(Record[9]), getMDOrNull(Record[10]), Record[11])),
1870 NextMetadataNo);
1871
1872 NextMetadataNo++;
1873 } else if (Version == 1) {
1874 // No upgrade necessary. A null field will be introduced to indicate
1875 // that no parameter information is available.
1876 MetadataList.assignValue(
1877 GET_OR_DISTINCT(DIGlobalVariable,
1878 (Context, getMDOrNull(Record[1]),
1879 getMDString(Record[2]), getMDString(Record[3]),
1880 getMDOrNull(Record[4]), Record[5],
1881 getDITypeRefOrNull(Record[6]), Record[7], Record[8],
1882 getMDOrNull(Record[10]), nullptr, Record[11])),
1883 NextMetadataNo);
1884
1885 NextMetadataNo++;
1886 } else if (Version == 0) {
1887 // Upgrade old metadata, which stored a global variable reference or a
1888 // ConstantInt here.
1889 NeedUpgradeToDIGlobalVariableExpression = true;
1890 Metadata *Expr = getMDOrNull(Record[9]);
1891 uint32_t AlignInBits = 0;
1892 if (Record.size() > 11) {
1893 if (Record[11] > (uint64_t)std::numeric_limits<uint32_t>::max())
1894 return error("Alignment value is too large");
1895 AlignInBits = Record[11];
1896 }
1897 GlobalVariable *Attach = nullptr;
1898 if (auto *CMD = dyn_cast_or_null<ConstantAsMetadata>(Expr)) {
1899 if (auto *GV = dyn_cast<GlobalVariable>(CMD->getValue())) {
1900 Attach = GV;
1901 Expr = nullptr;
1902 } else if (auto *CI = dyn_cast<ConstantInt>(CMD->getValue())) {
1903 Expr = DIExpression::get(Context,
1904 {dwarf::DW_OP_constu, CI->getZExtValue(),
1905 dwarf::DW_OP_stack_value});
1906 } else {
1907 Expr = nullptr;
1908 }
1909 }
1910 DIGlobalVariable *DGV = GET_OR_DISTINCT(
1911 DIGlobalVariable,
1912 (Context, getMDOrNull(Record[1]), getMDString(Record[2]),
1913 getMDString(Record[3]), getMDOrNull(Record[4]), Record[5],
1914 getDITypeRefOrNull(Record[6]), Record[7], Record[8],
1915 getMDOrNull(Record[10]), nullptr, AlignInBits));
1916
1917 DIGlobalVariableExpression *DGVE = nullptr;
1918 if (Attach || Expr)
1919 DGVE = DIGlobalVariableExpression::getDistinct(
1920 Context, DGV, Expr ? Expr : DIExpression::get(Context, {}));
1921 if (Attach)
1922 Attach->addDebugInfo(DGVE);
1923
1924 auto *MDNode = Expr ? cast<Metadata>(DGVE) : cast<Metadata>(DGV);
1925 MetadataList.assignValue(MDNode, NextMetadataNo);
1926 NextMetadataNo++;
1927 } else
1928 return error("Invalid record");
1929
1930 break;
1931 }
1932 case bitc::METADATA_LOCAL_VAR: {
1933 // 10th field is for the obseleted 'inlinedAt:' field.
1934 if (Record.size() < 8 || Record.size() > 10)
1935 return error("Invalid record");
1936
1937 IsDistinct = Record[0] & 1;
1938 bool HasAlignment = Record[0] & 2;
1939 // 2nd field used to be an artificial tag, either DW_TAG_auto_variable or
1940 // DW_TAG_arg_variable, if we have alignment flag encoded it means, that
1941 // this is newer version of record which doesn't have artificial tag.
1942 bool HasTag = !HasAlignment && Record.size() > 8;
1943 DINode::DIFlags Flags = static_cast<DINode::DIFlags>(Record[7 + HasTag]);
1944 uint32_t AlignInBits = 0;
1945 if (HasAlignment) {
1946 if (Record[8 + HasTag] > (uint64_t)std::numeric_limits<uint32_t>::max())
1947 return error("Alignment value is too large");
1948 AlignInBits = Record[8 + HasTag];
1949 }
1950 MetadataList.assignValue(
1951 GET_OR_DISTINCT(DILocalVariable,
1952 (Context, getMDOrNull(Record[1 + HasTag]),
1953 getMDString(Record[2 + HasTag]),
1954 getMDOrNull(Record[3 + HasTag]), Record[4 + HasTag],
1955 getDITypeRefOrNull(Record[5 + HasTag]),
1956 Record[6 + HasTag], Flags, AlignInBits)),
1957 NextMetadataNo);
1958 NextMetadataNo++;
1959 break;
1960 }
1961 case bitc::METADATA_LABEL: {
1962 if (Record.size() != 5)
1963 return error("Invalid record");
1964
1965 IsDistinct = Record[0] & 1;
1966 MetadataList.assignValue(
1967 GET_OR_DISTINCT(DILabel,
1968 (Context, getMDOrNull(Record[1]),
1969 getMDString(Record[2]),
1970 getMDOrNull(Record[3]), Record[4])),
1971 NextMetadataNo);
1972 NextMetadataNo++;
1973 break;
1974 }
1975 case bitc::METADATA_EXPRESSION: {
1976 if (Record.size() < 1)
1977 return error("Invalid record");
1978
1979 IsDistinct = Record[0] & 1;
1980 uint64_t Version = Record[0] >> 1;
1981 auto Elts = MutableArrayRef<uint64_t>(Record).slice(1);
1982
1983 SmallVector<uint64_t, 6> Buffer;
1984 if (Error Err = upgradeDIExpression(Version, Elts, Buffer))
1985 return Err;
1986
1987 MetadataList.assignValue(
1988 GET_OR_DISTINCT(DIExpression, (Context, Elts)), NextMetadataNo);
1989 NextMetadataNo++;
1990 break;
1991 }
1992 case bitc::METADATA_GLOBAL_VAR_EXPR: {
1993 if (Record.size() != 3)
1994 return error("Invalid record");
1995
1996 IsDistinct = Record[0];
1997 Metadata *Expr = getMDOrNull(Record[2]);
1998 if (!Expr)
1999 Expr = DIExpression::get(Context, {});
2000 MetadataList.assignValue(
2001 GET_OR_DISTINCT(DIGlobalVariableExpression,
2002 (Context, getMDOrNull(Record[1]), Expr)),
2003 NextMetadataNo);
2004 NextMetadataNo++;
2005 break;
2006 }
2007 case bitc::METADATA_OBJC_PROPERTY: {
2008 if (Record.size() != 8)
2009 return error("Invalid record");
2010
2011 IsDistinct = Record[0];
2012 MetadataList.assignValue(
2013 GET_OR_DISTINCT(DIObjCProperty,
2014 (Context, getMDString(Record[1]),
2015 getMDOrNull(Record[2]), Record[3],
2016 getMDString(Record[4]), getMDString(Record[5]),
2017 Record[6], getDITypeRefOrNull(Record[7]))),
2018 NextMetadataNo);
2019 NextMetadataNo++;
2020 break;
2021 }
2022 case bitc::METADATA_IMPORTED_ENTITY: {
2023 if (Record.size() != 6 && Record.size() != 7)
2024 return error("Invalid record");
2025
2026 IsDistinct = Record[0];
2027 bool HasFile = (Record.size() == 7);
2028 MetadataList.assignValue(
2029 GET_OR_DISTINCT(DIImportedEntity,
2030 (Context, Record[1], getMDOrNull(Record[2]),
2031 getDITypeRefOrNull(Record[3]),
2032 HasFile ? getMDOrNull(Record[6]) : nullptr,
2033 HasFile ? Record[4] : 0, getMDString(Record[5]))),
2034 NextMetadataNo);
2035 NextMetadataNo++;
2036 break;
2037 }
2038 case bitc::METADATA_STRING_OLD: {
2039 std::string String(Record.begin(), Record.end());
2040
2041 // Test for upgrading !llvm.loop.
2042 HasSeenOldLoopTags |= mayBeOldLoopAttachmentTag(String);
2043 ++NumMDStringLoaded;
2044 Metadata *MD = MDString::get(Context, String);
2045 MetadataList.assignValue(MD, NextMetadataNo);
2046 NextMetadataNo++;
2047 break;
2048 }
2049 case bitc::METADATA_STRINGS: {
2050 auto CreateNextMDString = [&](StringRef Str) {
2051 ++NumMDStringLoaded;
2052 MetadataList.assignValue(MDString::get(Context, Str), NextMetadataNo);
2053 NextMetadataNo++;
2054 };
2055 if (Error Err = parseMetadataStrings(Record, Blob, CreateNextMDString))
2056 return Err;
2057 break;
2058 }
2059 case bitc::METADATA_GLOBAL_DECL_ATTACHMENT: {
2060 if (Record.size() % 2 == 0)
2061 return error("Invalid record");
2062 unsigned ValueID = Record[0];
2063 if (ValueID >= ValueList.size())
2064 return error("Invalid record");
2065 if (auto *GO = dyn_cast<GlobalObject>(ValueList[ValueID]))
2066 if (Error Err = parseGlobalObjectAttachment(
2067 *GO, ArrayRef<uint64_t>(Record).slice(1)))
2068 return Err;
2069 break;
2070 }
2071 case bitc::METADATA_KIND: {
2072 // Support older bitcode files that had METADATA_KIND records in a
2073 // block with METADATA_BLOCK_ID.
2074 if (Error Err = parseMetadataKindRecord(Record))
2075 return Err;
2076 break;
2077 }
2078 case bitc::METADATA_ARG_LIST: {
2079 SmallVector<ValueAsMetadata *, 4> Elts;
2080 Elts.reserve(Record.size());
2081 for (uint64_t Elt : Record) {
2082 Metadata *MD = getMD(Elt);
2083 if (isa<MDNode>(MD) && cast<MDNode>(MD)->isTemporary())
2084 return error(
2085 "Invalid record: DIArgList should not contain forward refs");
2086 if (!isa<ValueAsMetadata>(MD))
2087 return error("Invalid record");
2088 Elts.push_back(cast<ValueAsMetadata>(MD));
2089 }
2090
2091 MetadataList.assignValue(DIArgList::get(Context, Elts), NextMetadataNo);
2092 NextMetadataNo++;
2093 break;
2094 }
2095 }
2096 return Error::success();
2097#undef GET_OR_DISTINCT
2098}
2099
2100Error MetadataLoader::MetadataLoaderImpl::parseMetadataStrings(
2101 ArrayRef<uint64_t> Record, StringRef Blob,
2102 function_ref<void(StringRef)> CallBack) {
2103 // All the MDStrings in the block are emitted together in a single
2104 // record. The strings are concatenated and stored in a blob along with
2105 // their sizes.
2106 if (Record.size() != 2)
2107 return error("Invalid record: metadata strings layout");
2108
2109 unsigned NumStrings = Record[0];
2110 unsigned StringsOffset = Record[1];
2111 if (!NumStrings)
2112 return error("Invalid record: metadata strings with no strings");
2113 if (StringsOffset > Blob.size())
2114 return error("Invalid record: metadata strings corrupt offset");
2115
2116 StringRef Lengths = Blob.slice(0, StringsOffset);
2117 SimpleBitstreamCursor R(Lengths);
2118
2119 StringRef Strings = Blob.drop_front(StringsOffset);
2120 do {
2121 if (R.AtEndOfStream())
2122 return error("Invalid record: metadata strings bad length");
2123
2124 Expected<uint32_t> MaybeSize = R.ReadVBR(6);
2125 if (!MaybeSize)
2126 return MaybeSize.takeError();
2127 uint32_t Size = MaybeSize.get();
2128 if (Strings.size() < Size)
2129 return error("Invalid record: metadata strings truncated chars");
2130
2131 CallBack(Strings.slice(0, Size));
2132 Strings = Strings.drop_front(Size);
2133 } while (--NumStrings);
2134
2135 return Error::success();
2136}
2137
2138Error MetadataLoader::MetadataLoaderImpl::parseGlobalObjectAttachment(
2139 GlobalObject &GO, ArrayRef<uint64_t> Record) {
2140 assert(Record.size() % 2 == 0)((void)0);
2141 for (unsigned I = 0, E = Record.size(); I != E; I += 2) {
2142 auto K = MDKindMap.find(Record[I]);
2143 if (K == MDKindMap.end())
2144 return error("Invalid ID");
2145 MDNode *MD =
2146 dyn_cast_or_null<MDNode>(getMetadataFwdRefOrLoad(Record[I + 1]));
2147 if (!MD)
2148 return error("Invalid metadata attachment: expect fwd ref to MDNode");
2149 GO.addMetadata(K->second, *MD);
2150 }
2151 return Error::success();
2152}
2153
2154/// Parse metadata attachments.
2155Error MetadataLoader::MetadataLoaderImpl::parseMetadataAttachment(
2156 Function &F, const SmallVectorImpl<Instruction *> &InstructionList) {
2157 if (Error Err = Stream.EnterSubBlock(bitc::METADATA_ATTACHMENT_ID))
2158 return Err;
2159
2160 SmallVector<uint64_t, 64> Record;
2161 PlaceholderQueue Placeholders;
2162
2163 while (true) {
2164 Expected<BitstreamEntry> MaybeEntry = Stream.advanceSkippingSubblocks();
2165 if (!MaybeEntry)
2166 return MaybeEntry.takeError();
2167 BitstreamEntry Entry = MaybeEntry.get();
2168
2169 switch (Entry.Kind) {
2170 case BitstreamEntry::SubBlock: // Handled for us already.
2171 case BitstreamEntry::Error:
2172 return error("Malformed block");
2173 case BitstreamEntry::EndBlock:
2174 resolveForwardRefsAndPlaceholders(Placeholders);
2175 return Error::success();
2176 case BitstreamEntry::Record:
2177 // The interesting case.
2178 break;
2179 }
2180
2181 // Read a metadata attachment record.
2182 Record.clear();
2183 ++NumMDRecordLoaded;
2184 Expected<unsigned> MaybeRecord = Stream.readRecord(Entry.ID, Record);
2185 if (!MaybeRecord)
2186 return MaybeRecord.takeError();
2187 switch (MaybeRecord.get()) {
2188 default: // Default behavior: ignore.
2189 break;
2190 case bitc::METADATA_ATTACHMENT: {
2191 unsigned RecordLength = Record.size();
2192 if (Record.empty())
2193 return error("Invalid record");
2194 if (RecordLength % 2 == 0) {
2195 // A function attachment.
2196 if (Error Err = parseGlobalObjectAttachment(F, Record))
2197 return Err;
2198 continue;
2199 }
2200
2201 // An instruction attachment.
2202 Instruction *Inst = InstructionList[Record[0]];
2203 for (unsigned i = 1; i != RecordLength; i = i + 2) {
2204 unsigned Kind = Record[i];
2205 DenseMap<unsigned, unsigned>::iterator I = MDKindMap.find(Kind);
2206 if (I == MDKindMap.end())
2207 return error("Invalid ID");
2208 if (I->second == LLVMContext::MD_tbaa && StripTBAA)
2209 continue;
2210
2211 auto Idx = Record[i + 1];
2212 if (Idx < (MDStringRef.size() + GlobalMetadataBitPosIndex.size()) &&
2213 !MetadataList.lookup(Idx)) {
2214 // Load the attachment if it is in the lazy-loadable range and hasn't
2215 // been loaded yet.
2216 lazyLoadOneMetadata(Idx, Placeholders);
2217 resolveForwardRefsAndPlaceholders(Placeholders);
2218 }
2219
2220 Metadata *Node = MetadataList.getMetadataFwdRef(Idx);
2221 if (isa<LocalAsMetadata>(Node))
2222 // Drop the attachment. This used to be legal, but there's no
2223 // upgrade path.
2224 break;
2225 MDNode *MD = dyn_cast_or_null<MDNode>(Node);
2226 if (!MD)
2227 return error("Invalid metadata attachment");
2228
2229 if (HasSeenOldLoopTags && I->second == LLVMContext::MD_loop)
2230 MD = upgradeInstructionLoopAttachment(*MD);
2231
2232 if (I->second == LLVMContext::MD_tbaa) {
2233 assert(!MD->isTemporary() && "should load MDs before attachments")((void)0);
2234 MD = UpgradeTBAANode(*MD);
2235 }
2236 Inst->setMetadata(I->second, MD);
2237 }
2238 break;
2239 }
2240 }
2241 }
2242}
2243
2244/// Parse a single METADATA_KIND record, inserting result in MDKindMap.
2245Error MetadataLoader::MetadataLoaderImpl::parseMetadataKindRecord(
2246 SmallVectorImpl<uint64_t> &Record) {
2247 if (Record.size() < 2)
2248 return error("Invalid record");
2249
2250 unsigned Kind = Record[0];
2251 SmallString<8> Name(Record.begin() + 1, Record.end());
2252
2253 unsigned NewKind = TheModule.getMDKindID(Name.str());
2254 if (!MDKindMap.insert(std::make_pair(Kind, NewKind)).second)
2255 return error("Conflicting METADATA_KIND records");
2256 return Error::success();
2257}
2258
2259/// Parse the metadata kinds out of the METADATA_KIND_BLOCK.
2260Error MetadataLoader::MetadataLoaderImpl::parseMetadataKinds() {
2261 if (Error Err = Stream.EnterSubBlock(bitc::METADATA_KIND_BLOCK_ID))
2
←
Taking false branch
→
2262 return Err;
2263
2264 SmallVector<uint64_t, 64> Record;
2265
2266 // Read all the records.
2267 while (true) {
3
←
Loop condition is true. Entering loop body
→
2268 Expected<BitstreamEntry> MaybeEntry = Stream.advanceSkippingSubblocks();
4
←
Calling 'BitstreamCursor::advanceSkippingSubblocks'
→
2269 if (!MaybeEntry)
2270 return MaybeEntry.takeError();
2271 BitstreamEntry Entry = MaybeEntry.get();
2272
2273 switch (Entry.Kind) {
2274 case BitstreamEntry::SubBlock: // Handled for us already.
2275 case BitstreamEntry::Error:
2276 return error("Malformed block");
2277 case BitstreamEntry::EndBlock:
2278 return Error::success();
2279 case BitstreamEntry::Record:
2280 // The interesting case.
2281 break;
2282 }
2283
2284 // Read a record.
2285 Record.clear();
2286 ++NumMDRecordLoaded;
2287 Expected<unsigned> MaybeCode = Stream.readRecord(Entry.ID, Record);
2288 if (!MaybeCode)
2289 return MaybeCode.takeError();
2290 switch (MaybeCode.get()) {
2291 default: // Default behavior: ignore.
2292 break;
2293 case bitc::METADATA_KIND: {
2294 if (Error Err = parseMetadataKindRecord(Record))
2295 return Err;
2296 break;
2297 }
2298 }
2299 }
2300}
2301
2302MetadataLoader &MetadataLoader::operator=(MetadataLoader &&RHS) {
2303 Pimpl = std::move(RHS.Pimpl);
2304 return *this;
2305}
2306MetadataLoader::MetadataLoader(MetadataLoader &&RHS)
2307 : Pimpl(std::move(RHS.Pimpl)) {}
2308
2309MetadataLoader::~MetadataLoader() = default;
2310MetadataLoader::MetadataLoader(BitstreamCursor &Stream, Module &TheModule,
2311 BitcodeReaderValueList &ValueList,
2312 bool IsImporting,
2313 std::function<Type *(unsigned)> getTypeByID)
2314 : Pimpl(std::make_unique<MetadataLoaderImpl>(
2315 Stream, TheModule, ValueList, std::move(getTypeByID), IsImporting)) {}
2316
2317Error MetadataLoader::parseMetadata(bool ModuleLevel) {
2318 return Pimpl->parseMetadata(ModuleLevel);
2319}
2320
2321bool MetadataLoader::hasFwdRefs() const { return Pimpl->hasFwdRefs(); }
2322
2323/// Return the given metadata, creating a replaceable forward reference if
2324/// necessary.
2325Metadata *MetadataLoader::getMetadataFwdRefOrLoad(unsigned Idx) {
2326 return Pimpl->getMetadataFwdRefOrLoad(Idx);
2327}
2328
2329DISubprogram *MetadataLoader::lookupSubprogramForFunction(Function *F) {
2330 return Pimpl->lookupSubprogramForFunction(F);
2331}
2332
2333Error MetadataLoader::parseMetadataAttachment(
2334 Function &F, const SmallVectorImpl<Instruction *> &InstructionList) {
2335 return Pimpl->parseMetadataAttachment(F, InstructionList);
2336}
2337
2338Error MetadataLoader::parseMetadataKinds() {
2339 return Pimpl->parseMetadataKinds();
1
Calling 'MetadataLoaderImpl::parseMetadataKinds'
→
2340}
2341
2342void MetadataLoader::setStripTBAA(bool StripTBAA) {
2343 return Pimpl->setStripTBAA(StripTBAA);
2344}
2345
2346bool MetadataLoader::isStrippingTBAA() { return Pimpl->isStrippingTBAA(); }
2347
2348unsigned MetadataLoader::size() const { return Pimpl->size(); }
2349void MetadataLoader::shrinkTo(unsigned N) { return Pimpl->shrinkTo(N); }
2350
2351void MetadataLoader::upgradeDebugIntrinsics(Function &F) {
2352 return Pimpl->upgradeDebugIntrinsics(F);
2353}
←

/usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Bitstream/BitstreamReader.h

→
1//===- BitstreamReader.h - Low-level bitstream reader interface -*- C++ -*-===//
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 header defines the BitstreamReader class. This class can be used to
10// read an arbitrary bitstream, regardless of its contents.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_BITSTREAM_BITSTREAMREADER_H
15#define LLVM_BITSTREAM_BITSTREAMREADER_H
16
17#include "llvm/ADT/ArrayRef.h"
18#include "llvm/ADT/SmallVector.h"
19#include "llvm/Bitstream/BitCodes.h"
20#include "llvm/Support/Endian.h"
21#include "llvm/Support/Error.h"
22#include "llvm/Support/ErrorHandling.h"
23#include "llvm/Support/MathExtras.h"
24#include "llvm/Support/MemoryBuffer.h"
25#include <algorithm>
26#include <cassert>
27#include <climits>
28#include <cstddef>
29#include <cstdint>
30#include <memory>
31#include <string>
32#include <utility>
33#include <vector>
34
35namespace llvm {
36
37/// This class maintains the abbreviations read from a block info block.
38class BitstreamBlockInfo {
39public:
40 /// This contains information emitted to BLOCKINFO_BLOCK blocks. These
41 /// describe abbreviations that all blocks of the specified ID inherit.
42 struct BlockInfo {
43 unsigned BlockID = 0;
44 std::vector<std::shared_ptr<BitCodeAbbrev>> Abbrevs;
45 std::string Name;
46 std::vector<std::pair<unsigned, std::string>> RecordNames;
47 };
48
49private:
50 std::vector<BlockInfo> BlockInfoRecords;
51
52public:
53 /// If there is block info for the specified ID, return it, otherwise return
54 /// null.
55 const BlockInfo *getBlockInfo(unsigned BlockID) const {
56 // Common case, the most recent entry matches BlockID.
57 if (!BlockInfoRecords.empty() && BlockInfoRecords.back().BlockID == BlockID)
58 return &BlockInfoRecords.back();
59
60 for (unsigned i = 0, e = static_cast<unsigned>(BlockInfoRecords.size());
61 i != e; ++i)
62 if (BlockInfoRecords[i].BlockID == BlockID)
63 return &BlockInfoRecords[i];
64 return nullptr;
65 }
66
67 BlockInfo &getOrCreateBlockInfo(unsigned BlockID) {
68 if (const BlockInfo *BI = getBlockInfo(BlockID))
69 return *const_cast<BlockInfo*>(BI);
70
71 // Otherwise, add a new record.
72 BlockInfoRecords.emplace_back();
73 BlockInfoRecords.back().BlockID = BlockID;
74 return BlockInfoRecords.back();
75 }
76};
77
78/// This represents a position within a bitstream. There may be multiple
79/// independent cursors reading within one bitstream, each maintaining their
80/// own local state.
81class SimpleBitstreamCursor {
82 ArrayRef<uint8_t> BitcodeBytes;
83 size_t NextChar = 0;
84
85public:
86 /// This is the current data we have pulled from the stream but have not
87 /// returned to the client. This is specifically and intentionally defined to
88 /// follow the word size of the host machine for efficiency. We use word_t in
89 /// places that are aware of this to make it perfectly explicit what is going
90 /// on.
91 using word_t = size_t;
92
93private:
94 word_t CurWord = 0;
95
96 /// This is the number of bits in CurWord that are valid. This is always from
97 /// [0...bits_of(size_t)-1] inclusive.
98 unsigned BitsInCurWord = 0;
99
100public:
101 static const constexpr size_t MaxChunkSize = sizeof(word_t) * 8;
102
103 SimpleBitstreamCursor() = default;
104 explicit SimpleBitstreamCursor(ArrayRef<uint8_t> BitcodeBytes)
105 : BitcodeBytes(BitcodeBytes) {}
106 explicit SimpleBitstreamCursor(StringRef BitcodeBytes)
107 : BitcodeBytes(arrayRefFromStringRef(BitcodeBytes)) {}
108 explicit SimpleBitstreamCursor(MemoryBufferRef BitcodeBytes)
109 : SimpleBitstreamCursor(BitcodeBytes.getBuffer()) {}
110
111 bool canSkipToPos(size_t pos) const {
112 // pos can be skipped to if it is a valid address or one byte past the end.
113 return pos <= BitcodeBytes.size();
114 }
115
116 bool AtEndOfStream() {
117 return BitsInCurWord == 0 && BitcodeBytes.size() <= NextChar;
118 }
119
120 /// Return the bit # of the bit we are reading.
121 uint64_t GetCurrentBitNo() const {
122 return NextChar*CHAR_BIT8 - BitsInCurWord;
123 }
124
125 // Return the byte # of the current bit.
126 uint64_t getCurrentByteNo() const { return GetCurrentBitNo() / 8; }
127
128 ArrayRef<uint8_t> getBitcodeBytes() const { return BitcodeBytes; }
129
130 /// Reset the stream to the specified bit number.
131 Error JumpToBit(uint64_t BitNo) {
132 size_t ByteNo = size_t(BitNo/8) & ~(sizeof(word_t)-1);
133 unsigned WordBitNo = unsigned(BitNo & (sizeof(word_t)*8-1));
134 assert(canSkipToPos(ByteNo) && "Invalid location")((void)0);
135
136 // Move the cursor to the right word.
137 NextChar = ByteNo;
138 BitsInCurWord = 0;
139
140 // Skip over any bits that are already consumed.
141 if (WordBitNo) {
142 if (Expected<word_t> Res = Read(WordBitNo))
143 return Error::success();
144 else
145 return Res.takeError();
146 }
147
148 return Error::success();
149 }
150
151 /// Get a pointer into the bitstream at the specified byte offset.
152 const uint8_t *getPointerToByte(uint64_t ByteNo, uint64_t NumBytes) {
153 return BitcodeBytes.data() + ByteNo;
154 }
155
156 /// Get a pointer into the bitstream at the specified bit offset.
157 ///
158 /// The bit offset must be on a byte boundary.
159 const uint8_t *getPointerToBit(uint64_t BitNo, uint64_t NumBytes) {
160 assert(!(BitNo % 8) && "Expected bit on byte boundary")((void)0);
161 return getPointerToByte(BitNo / 8, NumBytes);
162 }
163
164 Error fillCurWord() {
165 if (NextChar >= BitcodeBytes.size())
166 return createStringError(std::errc::io_error,
167 "Unexpected end of file reading %u of %u bytes",
168 NextChar, BitcodeBytes.size());
169
170 // Read the next word from the stream.
171 const uint8_t *NextCharPtr = BitcodeBytes.data() + NextChar;
172 unsigned BytesRead;
173 if (BitcodeBytes.size() >= NextChar + sizeof(word_t)) {
174 BytesRead = sizeof(word_t);
175 CurWord =
176 support::endian::read<word_t, support::little, support::unaligned>(
177 NextCharPtr);
178 } else {
179 // Short read.
180 BytesRead = BitcodeBytes.size() - NextChar;
181 CurWord = 0;
182 for (unsigned B = 0; B != BytesRead; ++B)
183 CurWord |= uint64_t(NextCharPtr[B]) << (B * 8);
184 }
185 NextChar += BytesRead;
186 BitsInCurWord = BytesRead * 8;
187 return Error::success();
188 }
189
190 Expected<word_t> Read(unsigned NumBits) {
191 static const unsigned BitsInWord = MaxChunkSize;
192
193 assert(NumBits && NumBits <= BitsInWord &&((void)0)
194 "Cannot return zero or more than BitsInWord bits!")((void)0);
195
196 static const unsigned Mask = sizeof(word_t) > 4 ? 0x3f : 0x1f;
11
←
'?' condition is true
→
197
198 // If the field is fully contained by CurWord, return it quickly.
199 if (BitsInCurWord >= NumBits) {
12
←
Assuming 'NumBits' is > field 'BitsInCurWord'
→
13
←
Taking false branch
→
200 word_t R = CurWord & (~word_t(0) >> (BitsInWord - NumBits));
201
202 // Use a mask to avoid undefined behavior.
203 CurWord >>= (NumBits & Mask);
204
205 BitsInCurWord -= NumBits;
206 return R;
207 }
208
209 word_t R = BitsInCurWord
13.1
Field 'BitsInCurWord' is not equal to 0
13.1
Field 'BitsInCurWord' is not equal to 0
13.1
Field 'BitsInCurWord' is not equal to 0
 ? CurWord : 0;
14
←
'?' condition is true
→
210 unsigned BitsLeft = NumBits - BitsInCurWord;
211
212 if (Error fillResult = fillCurWord())
15
←
Calling 'Error::operator bool'
→
17
←
Returning from 'Error::operator bool'
→
18
←
Taking false branch
→
213 return std::move(fillResult);
214
215 // If we run out of data, abort.
216 if (BitsLeft > BitsInCurWord)
19
←
Assuming 'BitsLeft' is <= field 'BitsInCurWord'
→
20
←
Taking false branch
→
217 return createStringError(std::errc::io_error,
218 "Unexpected end of file reading %u of %u bits",
219 BitsInCurWord, BitsLeft);
220
221 word_t R2 = CurWord & (~word_t(0) >> (BitsInWord - BitsLeft));
21
←
The result of the right shift is undefined due to shifting by '64', which is greater or equal to the width of type 'llvm::SimpleBitstreamCursor::word_t'
222
223 // Use a mask to avoid undefined behavior.
224 CurWord >>= (BitsLeft & Mask);
225
226 BitsInCurWord -= BitsLeft;
227
228 R |= R2 << (NumBits - BitsLeft);
229
230 return R;
231 }
232
233 Expected<uint32_t> ReadVBR(unsigned NumBits) {
234 Expected<unsigned> MaybeRead = Read(NumBits);
235 if (!MaybeRead)
236 return MaybeRead;
237 uint32_t Piece = MaybeRead.get();
238
239 if ((Piece & (1U << (NumBits-1))) == 0)
240 return Piece;
241
242 uint32_t Result = 0;
243 unsigned NextBit = 0;
244 while (true) {
245 Result |= (Piece & ((1U << (NumBits-1))-1)) << NextBit;
246
247 if ((Piece & (1U << (NumBits-1))) == 0)
248 return Result;
249
250 NextBit += NumBits-1;
251 MaybeRead = Read(NumBits);
252 if (!MaybeRead)
253 return MaybeRead;
254 Piece = MaybeRead.get();
255 }
256 }
257
258 // Read a VBR that may have a value up to 64-bits in size. The chunk size of
259 // the VBR must still be <= 32 bits though.
260 Expected<uint64_t> ReadVBR64(unsigned NumBits) {
261 Expected<uint64_t> MaybeRead = Read(NumBits);
262 if (!MaybeRead)
263 return MaybeRead;
264 uint32_t Piece = MaybeRead.get();
265
266 if ((Piece & (1U << (NumBits-1))) == 0)
267 return uint64_t(Piece);
268
269 uint64_t Result = 0;
270 unsigned NextBit = 0;
271 while (true) {
272 Result |= uint64_t(Piece & ((1U << (NumBits-1))-1)) << NextBit;
273
274 if ((Piece & (1U << (NumBits-1))) == 0)
275 return Result;
276
277 NextBit += NumBits-1;
278 MaybeRead = Read(NumBits);
279 if (!MaybeRead)
280 return MaybeRead;
281 Piece = MaybeRead.get();
282 }
283 }
284
285 void SkipToFourByteBoundary() {
286 // If word_t is 64-bits and if we've read less than 32 bits, just dump
287 // the bits we have up to the next 32-bit boundary.
288 if (sizeof(word_t) > 4 &&
289 BitsInCurWord >= 32) {
290 CurWord >>= BitsInCurWord-32;
291 BitsInCurWord = 32;
292 return;
293 }
294
295 BitsInCurWord = 0;
296 }
297
298 /// Return the size of the stream in bytes.
299 size_t SizeInBytes() const { return BitcodeBytes.size(); }
300
301 /// Skip to the end of the file.
302 void skipToEnd() { NextChar = BitcodeBytes.size(); }
303};
304
305/// When advancing through a bitstream cursor, each advance can discover a few
306/// different kinds of entries:
307struct BitstreamEntry {
308 enum {
309 Error, // Malformed bitcode was found.
310 EndBlock, // We've reached the end of the current block, (or the end of the
311 // file, which is treated like a series of EndBlock records.
312 SubBlock, // This is the start of a new subblock of a specific ID.
313 Record // This is a record with a specific AbbrevID.
314 } Kind;
315
316 unsigned ID;
317
318 static BitstreamEntry getError() {
319 BitstreamEntry E; E.Kind = Error; return E;
320 }
321
322 static BitstreamEntry getEndBlock() {
323 BitstreamEntry E; E.Kind = EndBlock; return E;
324 }
325
326 static BitstreamEntry getSubBlock(unsigned ID) {
327 BitstreamEntry E; E.Kind = SubBlock; E.ID = ID; return E;
328 }
329
330 static BitstreamEntry getRecord(unsigned AbbrevID) {
331 BitstreamEntry E; E.Kind = Record; E.ID = AbbrevID; return E;
332 }
333};
334
335/// This represents a position within a bitcode file, implemented on top of a
336/// SimpleBitstreamCursor.
337///
338/// Unlike iterators, BitstreamCursors are heavy-weight objects that should not
339/// be passed by value.
340class BitstreamCursor : SimpleBitstreamCursor {
341 // This is the declared size of code values used for the current block, in
342 // bits.
343 unsigned CurCodeSize = 2;
344
345 /// Abbrevs installed at in this block.
346 std::vector<std::shared_ptr<BitCodeAbbrev>> CurAbbrevs;
347
348 struct Block {
349 unsigned PrevCodeSize;
350 std::vector<std::shared_ptr<BitCodeAbbrev>> PrevAbbrevs;
351
352 explicit Block(unsigned PCS) : PrevCodeSize(PCS) {}
353 };
354
355 /// This tracks the codesize of parent blocks.
356 SmallVector<Block, 8> BlockScope;
357
358 BitstreamBlockInfo *BlockInfo = nullptr;
359
360public:
361 static const size_t MaxChunkSize = sizeof(word_t) * 8;
362
363 BitstreamCursor() = default;
364 explicit BitstreamCursor(ArrayRef<uint8_t> BitcodeBytes)
365 : SimpleBitstreamCursor(BitcodeBytes) {}
366 explicit BitstreamCursor(StringRef BitcodeBytes)
367 : SimpleBitstreamCursor(BitcodeBytes) {}
368 explicit BitstreamCursor(MemoryBufferRef BitcodeBytes)
369 : SimpleBitstreamCursor(BitcodeBytes) {}
370
371 using SimpleBitstreamCursor::AtEndOfStream;
372 using SimpleBitstreamCursor::canSkipToPos;
373 using SimpleBitstreamCursor::fillCurWord;
374 using SimpleBitstreamCursor::getBitcodeBytes;
375 using SimpleBitstreamCursor::GetCurrentBitNo;
376 using SimpleBitstreamCursor::getCurrentByteNo;
377 using SimpleBitstreamCursor::getPointerToByte;
378 using SimpleBitstreamCursor::JumpToBit;
379 using SimpleBitstreamCursor::Read;
380 using SimpleBitstreamCursor::ReadVBR;
381 using SimpleBitstreamCursor::ReadVBR64;
382 using SimpleBitstreamCursor::SizeInBytes;
383 using SimpleBitstreamCursor::skipToEnd;
384
385 /// Return the number of bits used to encode an abbrev #.
386 unsigned getAbbrevIDWidth() const { return CurCodeSize; }
387
388 /// Flags that modify the behavior of advance().
389 enum {
390 /// If this flag is used, the advance() method does not automatically pop
391 /// the block scope when the end of a block is reached.
392 AF_DontPopBlockAtEnd = 1,
393
394 /// If this flag is used, abbrev entries are returned just like normal
395 /// records.
396 AF_DontAutoprocessAbbrevs = 2
397 };
398
399 /// Advance the current bitstream, returning the next entry in the stream.
400 Expected<BitstreamEntry> advance(unsigned Flags = 0) {
401 while (true) {
7
←
Loop condition is true. Entering loop body
→
402 if (AtEndOfStream())
8
←
Taking false branch
→
403 return BitstreamEntry::getError();
404
405 Expected<unsigned> MaybeCode = ReadCode();
9
←
Calling 'BitstreamCursor::ReadCode'
→
406 if (!MaybeCode)
407 return MaybeCode.takeError();
408 unsigned Code = MaybeCode.get();
409
410 if (Code == bitc::END_BLOCK) {
411 // Pop the end of the block unless Flags tells us not to.
412 if (!(Flags & AF_DontPopBlockAtEnd) && ReadBlockEnd())
413 return BitstreamEntry::getError();
414 return BitstreamEntry::getEndBlock();
415 }
416
417 if (Code == bitc::ENTER_SUBBLOCK) {
418 if (Expected<unsigned> MaybeSubBlock = ReadSubBlockID())
419 return BitstreamEntry::getSubBlock(MaybeSubBlock.get());
420 else
421 return MaybeSubBlock.takeError();
422 }
423
424 if (Code == bitc::DEFINE_ABBREV &&
425 !(Flags & AF_DontAutoprocessAbbrevs)) {
426 // We read and accumulate abbrev's, the client can't do anything with
427 // them anyway.
428 if (Error Err = ReadAbbrevRecord())
429 return std::move(Err);
430 continue;
431 }
432
433 return BitstreamEntry::getRecord(Code);
434 }
435 }
436
437 /// This is a convenience function for clients that don't expect any
438 /// subblocks. This just skips over them automatically.
439 Expected<BitstreamEntry> advanceSkippingSubblocks(unsigned Flags = 0) {
440 while (true) {
5
←
Loop condition is true. Entering loop body
→
441 // If we found a normal entry, return it.
442 Expected<BitstreamEntry> MaybeEntry = advance(Flags);
6
←
Calling 'BitstreamCursor::advance'
→
443 if (!MaybeEntry)
444 return MaybeEntry;
445 BitstreamEntry Entry = MaybeEntry.get();
446
447 if (Entry.Kind != BitstreamEntry::SubBlock)
448 return Entry;
449
450 // If we found a sub-block, just skip over it and check the next entry.
451 if (Error Err = SkipBlock())
452 return std::move(Err);
453 }
454 }
455
456 Expected<unsigned> ReadCode() { return Read(CurCodeSize); }
10
←
Calling 'SimpleBitstreamCursor::Read'
→
457
458 // Block header:
459 // [ENTER_SUBBLOCK, blockid, newcodelen, <align4bytes>, blocklen]
460
461 /// Having read the ENTER_SUBBLOCK code, read the BlockID for the block.
462 Expected<unsigned> ReadSubBlockID() { return ReadVBR(bitc::BlockIDWidth); }
463
464 /// Having read the ENTER_SUBBLOCK abbrevid and a BlockID, skip over the body
465 /// of this block.
466 Error SkipBlock() {
467 // Read and ignore the codelen value.
468 if (Expected<uint32_t> Res = ReadVBR(bitc::CodeLenWidth))
469 ; // Since we are skipping this block, we don't care what code widths are
470 // used inside of it.
471 else
472 return Res.takeError();
473
474 SkipToFourByteBoundary();
475 Expected<unsigned> MaybeNum = Read(bitc::BlockSizeWidth);
476 if (!MaybeNum)
477 return MaybeNum.takeError();
478 size_t NumFourBytes = MaybeNum.get();
479
480 // Check that the block wasn't partially defined, and that the offset isn't
481 // bogus.
482 size_t SkipTo = GetCurrentBitNo() + NumFourBytes * 4 * 8;
483 if (AtEndOfStream())
484 return createStringError(std::errc::illegal_byte_sequence,
485 "can't skip block: already at end of stream");
486 if (!canSkipToPos(SkipTo / 8))
487 return createStringError(std::errc::illegal_byte_sequence,
488 "can't skip to bit %zu from %" PRIu64"llu", SkipTo,
489 GetCurrentBitNo());
490
491 if (Error Res = JumpToBit(SkipTo))
492 return Res;
493
494 return Error::success();
495 }
496
497 /// Having read the ENTER_SUBBLOCK abbrevid, and enter the block.
498 Error EnterSubBlock(unsigned BlockID, unsigned *NumWordsP = nullptr);
499
500 bool ReadBlockEnd() {
501 if (BlockScope.empty()) return true;
502
503 // Block tail:
504 // [END_BLOCK, <align4bytes>]
505 SkipToFourByteBoundary();
506
507 popBlockScope();
508 return false;
509 }
510
511private:
512 void popBlockScope() {
513 CurCodeSize = BlockScope.back().PrevCodeSize;
514
515 CurAbbrevs = std::move(BlockScope.back().PrevAbbrevs);
516 BlockScope.pop_back();
517 }
518
519 //===--------------------------------------------------------------------===//
520 // Record Processing
521 //===--------------------------------------------------------------------===//
522
523public:
524 /// Return the abbreviation for the specified AbbrevId.
525 const BitCodeAbbrev *getAbbrev(unsigned AbbrevID) {
526 unsigned AbbrevNo = AbbrevID - bitc::FIRST_APPLICATION_ABBREV;
527 if (AbbrevNo >= CurAbbrevs.size())
528 report_fatal_error("Invalid abbrev number");
529 return CurAbbrevs[AbbrevNo].get();
530 }
531
532 /// Read the current record and discard it, returning the code for the record.
533 Expected<unsigned> skipRecord(unsigned AbbrevID);
534
535 Expected<unsigned> readRecord(unsigned AbbrevID,
536 SmallVectorImpl<uint64_t> &Vals,
537 StringRef *Blob = nullptr);
538
539 //===--------------------------------------------------------------------===//
540 // Abbrev Processing
541 //===--------------------------------------------------------------------===//
542 Error ReadAbbrevRecord();
543
544 /// Read and return a block info block from the bitstream. If an error was
545 /// encountered, return None.
546 ///
547 /// \param ReadBlockInfoNames Whether to read block/record name information in
548 /// the BlockInfo block. Only llvm-bcanalyzer uses this.
549 Expected<Optional<BitstreamBlockInfo>>
550 ReadBlockInfoBlock(bool ReadBlockInfoNames = false);
551
552 /// Set the block info to be used by this BitstreamCursor to interpret
553 /// abbreviated records.
554 void setBlockInfo(BitstreamBlockInfo *BI) { BlockInfo = BI; }
555};
556
557} // end llvm namespace
558
559#endif // LLVM_BITSTREAM_BITSTREAMREADER_H
←

/usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Support/Error.h

1//===- llvm/Support/Error.h - Recoverable error handling --------*- C++ -*-===//
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 an API used to report recoverable errors.
10//
11//===----------------------------------------------------------------------===//
12
13#ifndef LLVM_SUPPORT_ERROR_H
14#define LLVM_SUPPORT_ERROR_H
15
16#include "llvm-c/Error.h"
17#include "llvm/ADT/STLExtras.h"
18#include "llvm/ADT/SmallVector.h"
19#include "llvm/ADT/StringExtras.h"
20#include "llvm/ADT/Twine.h"
21#include "llvm/Config/abi-breaking.h"
22#include "llvm/Support/AlignOf.h"
23#include "llvm/Support/Compiler.h"
24#include "llvm/Support/Debug.h"
25#include "llvm/Support/ErrorHandling.h"
26#include "llvm/Support/ErrorOr.h"
27#include "llvm/Support/Format.h"
28#include "llvm/Support/raw_ostream.h"
29#include <algorithm>
30#include <cassert>
31#include <cstdint>
32#include <cstdlib>
33#include <functional>
34#include <memory>
35#include <new>
36#include <string>
37#include <system_error>
38#include <type_traits>
39#include <utility>
40#include <vector>
41
42namespace llvm {
43
44class ErrorSuccess;
45
46/// Base class for error info classes. Do not extend this directly: Extend
47/// the ErrorInfo template subclass instead.
48class ErrorInfoBase {
49public:
50 virtual ~ErrorInfoBase() = default;
51
52 /// Print an error message to an output stream.
53 virtual void log(raw_ostream &OS) const = 0;
54
55 /// Return the error message as a string.
56 virtual std::string message() const {
57 std::string Msg;
58 raw_string_ostream OS(Msg);
59 log(OS);
60 return OS.str();
61 }
62
63 /// Convert this error to a std::error_code.
64 ///
65 /// This is a temporary crutch to enable interaction with code still
66 /// using std::error_code. It will be removed in the future.
67 virtual std::error_code convertToErrorCode() const = 0;
68
69 // Returns the class ID for this type.
70 static const void *classID() { return &ID; }
71
72 // Returns the class ID for the dynamic type of this ErrorInfoBase instance.
73 virtual const void *dynamicClassID() const = 0;
74
75 // Check whether this instance is a subclass of the class identified by
76 // ClassID.
77 virtual bool isA(const void *const ClassID) const {
78 return ClassID == classID();
79 }
80
81 // Check whether this instance is a subclass of ErrorInfoT.
82 template <typename ErrorInfoT> bool isA() const {
83 return isA(ErrorInfoT::classID());
84 }
85
86private:
87 virtual void anchor();
88
89 static char ID;
90};
91
92/// Lightweight error class with error context and mandatory checking.
93///
94/// Instances of this class wrap a ErrorInfoBase pointer. Failure states
95/// are represented by setting the pointer to a ErrorInfoBase subclass
96/// instance containing information describing the failure. Success is
97/// represented by a null pointer value.
98///
99/// Instances of Error also contains a 'Checked' flag, which must be set
100/// before the destructor is called, otherwise the destructor will trigger a
101/// runtime error. This enforces at runtime the requirement that all Error
102/// instances be checked or returned to the caller.
103///
104/// There are two ways to set the checked flag, depending on what state the
105/// Error instance is in. For Error instances indicating success, it
106/// is sufficient to invoke the boolean conversion operator. E.g.:
107///
108/// @code{.cpp}
109/// Error foo(<...>);
110///
111/// if (auto E = foo(<...>))
112/// return E; // <- Return E if it is in the error state.
113/// // We have verified that E was in the success state. It can now be safely
114/// // destroyed.
115/// @endcode
116///
117/// A success value *can not* be dropped. For example, just calling 'foo(<...>)'
118/// without testing the return value will raise a runtime error, even if foo
119/// returns success.
120///
121/// For Error instances representing failure, you must use either the
122/// handleErrors or handleAllErrors function with a typed handler. E.g.:
123///
124/// @code{.cpp}
125/// class MyErrorInfo : public ErrorInfo<MyErrorInfo> {
126/// // Custom error info.
127/// };
128///
129/// Error foo(<...>) { return make_error<MyErrorInfo>(...); }
130///
131/// auto E = foo(<...>); // <- foo returns failure with MyErrorInfo.
132/// auto NewE =
133/// handleErrors(E,
134/// [](const MyErrorInfo &M) {
135/// // Deal with the error.
136/// },
137/// [](std::unique_ptr<OtherError> M) -> Error {
138/// if (canHandle(*M)) {
139/// // handle error.
140/// return Error::success();
141/// }
142/// // Couldn't handle this error instance. Pass it up the stack.
143/// return Error(std::move(M));
144/// );
145/// // Note - we must check or return NewE in case any of the handlers
146/// // returned a new error.
147/// @endcode
148///
149/// The handleAllErrors function is identical to handleErrors, except
150/// that it has a void return type, and requires all errors to be handled and
151/// no new errors be returned. It prevents errors (assuming they can all be
152/// handled) from having to be bubbled all the way to the top-level.
153///
154/// *All* Error instances must be checked before destruction, even if
155/// they're moved-assigned or constructed from Success values that have already
156/// been checked. This enforces checking through all levels of the call stack.
157class LLVM_NODISCARD[[clang::warn_unused_result]] Error {
158 // ErrorList needs to be able to yank ErrorInfoBase pointers out of Errors
159 // to add to the error list. It can't rely on handleErrors for this, since
160 // handleErrors does not support ErrorList handlers.
161 friend class ErrorList;
162
163 // handleErrors needs to be able to set the Checked flag.
164 template <typename... HandlerTs>
165 friend Error handleErrors(Error E, HandlerTs &&... Handlers);
166
167 // Expected<T> needs to be able to steal the payload when constructed from an
168 // error.
169 template <typename T> friend class Expected;
170
171 // wrap needs to be able to steal the payload.
172 friend LLVMErrorRef wrap(Error);
173
174protected:
175 /// Create a success value. Prefer using 'Error::success()' for readability
176 Error() {
177 setPtr(nullptr);
178 setChecked(false);
179 }
180
181public:
182 /// Create a success value.
183 static ErrorSuccess success();
184
185 // Errors are not copy-constructable.
186 Error(const Error &Other) = delete;
187
188 /// Move-construct an error value. The newly constructed error is considered
189 /// unchecked, even if the source error had been checked. The original error
190 /// becomes a checked Success value, regardless of its original state.
191 Error(Error &&Other) {
192 setChecked(true);
193 *this = std::move(Other);
194 }
195
196 /// Create an error value. Prefer using the 'make_error' function, but
197 /// this constructor can be useful when "re-throwing" errors from handlers.
198 Error(std::unique_ptr<ErrorInfoBase> Payload) {
199 setPtr(Payload.release());
200 setChecked(false);
201 }
202
203 // Errors are not copy-assignable.
204 Error &operator=(const Error &Other) = delete;
205
206 /// Move-assign an error value. The current error must represent success, you
207 /// you cannot overwrite an unhandled error. The current error is then
208 /// considered unchecked. The source error becomes a checked success value,
209 /// regardless of its original state.
210 Error &operator=(Error &&Other) {
211 // Don't allow overwriting of unchecked values.
212 assertIsChecked();
213 setPtr(Other.getPtr());
214
215 // This Error is unchecked, even if the source error was checked.
216 setChecked(false);
217
218 // Null out Other's payload and set its checked bit.
219 Other.setPtr(nullptr);
220 Other.setChecked(true);
221
222 return *this;
223 }
224
225 /// Destroy a Error. Fails with a call to abort() if the error is
226 /// unchecked.
227 ~Error() {
228 assertIsChecked();
229 delete getPtr();
230 }
231
232 /// Bool conversion. Returns true if this Error is in a failure state,
233 /// and false if it is in an accept state. If the error is in a Success state
234 /// it will be considered checked.
235 explicit operator bool() {
236 setChecked(getPtr() == nullptr);
237 return getPtr() != nullptr;
16
←
Returning zero, which participates in a condition later
→
238 }
239
240 /// Check whether one error is a subclass of another.
241 template <typename ErrT> bool isA() const {
242 return getPtr() && getPtr()->isA(ErrT::classID());
243 }
244
245 /// Returns the dynamic class id of this error, or null if this is a success
246 /// value.
247 const void* dynamicClassID() const {
248 if (!getPtr())
249 return nullptr;
250 return getPtr()->dynamicClassID();
251 }
252
253private:
254#if LLVM_ENABLE_ABI_BREAKING_CHECKS0
255 // assertIsChecked() happens very frequently, but under normal circumstances
256 // is supposed to be a no-op. So we want it to be inlined, but having a bunch
257 // of debug prints can cause the function to be too large for inlining. So
258 // it's important that we define this function out of line so that it can't be
259 // inlined.
260 LLVM_ATTRIBUTE_NORETURN__attribute__((noreturn))
261 void fatalUncheckedError() const;
262#endif
263
264 void assertIsChecked() {
265#if LLVM_ENABLE_ABI_BREAKING_CHECKS0
266 if (LLVM_UNLIKELY(!getChecked() || getPtr())__builtin_expect((bool)(!getChecked() || getPtr()), false))
267 fatalUncheckedError();
268#endif
269 }
270
271 ErrorInfoBase *getPtr() const {
272#if LLVM_ENABLE_ABI_BREAKING_CHECKS0
273 return reinterpret_cast<ErrorInfoBase*>(
274 reinterpret_cast<uintptr_t>(Payload) &
275 ~static_cast<uintptr_t>(0x1));
276#else
277 return Payload;
278#endif
279 }
280
281 void setPtr(ErrorInfoBase *EI) {
282#if LLVM_ENABLE_ABI_BREAKING_CHECKS0
283 Payload = reinterpret_cast<ErrorInfoBase*>(
284 (reinterpret_cast<uintptr_t>(EI) &
285 ~static_cast<uintptr_t>(0x1)) |
286 (reinterpret_cast<uintptr_t>(Payload) & 0x1));
287#else
288 Payload = EI;
289#endif
290 }
291
292 bool getChecked() const {
293#if LLVM_ENABLE_ABI_BREAKING_CHECKS0
294 return (reinterpret_cast<uintptr_t>(Payload) & 0x1) == 0;
295#else
296 return true;
297#endif
298 }
299
300 void setChecked(bool V) {
301#if LLVM_ENABLE_ABI_BREAKING_CHECKS0
302 Payload = reinterpret_cast<ErrorInfoBase*>(
303 (reinterpret_cast<uintptr_t>(Payload) &
304 ~static_cast<uintptr_t>(0x1)) |
305 (V ? 0 : 1));
306#endif
307 }
308
309 std::unique_ptr<ErrorInfoBase> takePayload() {
310 std::unique_ptr<ErrorInfoBase> Tmp(getPtr());
311 setPtr(nullptr);
312 setChecked(true);
313 return Tmp;
314 }
315
316 friend raw_ostream &operator<<(raw_ostream &OS, const Error &E) {
317 if (auto P = E.getPtr())
318 P->log(OS);
319 else
320 OS << "success";
321 return OS;
322 }
323
324 ErrorInfoBase *Payload = nullptr;
325};
326
327/// Subclass of Error for the sole purpose of identifying the success path in
328/// the type system. This allows to catch invalid conversion to Expected<T> at
329/// compile time.
330class ErrorSuccess final : public Error {};
331
332inline ErrorSuccess Error::success() { return ErrorSuccess(); }
333
334/// Make a Error instance representing failure using the given error info
335/// type.
336template <typename ErrT, typename... ArgTs> Error make_error(ArgTs &&... Args) {
337 return Error(std::make_unique<ErrT>(std::forward<ArgTs>(Args)...));
338}
339
340/// Base class for user error types. Users should declare their error types
341/// like:
342///
343/// class MyError : public ErrorInfo<MyError> {
344/// ....
345/// };
346///
347/// This class provides an implementation of the ErrorInfoBase::kind
348/// method, which is used by the Error RTTI system.
349template <typename ThisErrT, typename ParentErrT = ErrorInfoBase>
350class ErrorInfo : public ParentErrT {
351public:
352 using ParentErrT::ParentErrT; // inherit constructors
353
354 static const void *classID() { return &ThisErrT::ID; }
355
356 const void *dynamicClassID() const override { return &ThisErrT::ID; }
357
358 bool isA(const void *const ClassID) const override {
359 return ClassID == classID() || ParentErrT::isA(ClassID);
360 }
361};
362
363/// Special ErrorInfo subclass representing a list of ErrorInfos.
364/// Instances of this class are constructed by joinError.
365class ErrorList final : public ErrorInfo<ErrorList> {
366 // handleErrors needs to be able to iterate the payload list of an
367 // ErrorList.
368 template <typename... HandlerTs>
369 friend Error handleErrors(Error E, HandlerTs &&... Handlers);
370
371 // joinErrors is implemented in terms of join.
372 friend Error joinErrors(Error, Error);
373
374public:
375 void log(raw_ostream &OS) const override {
376 OS << "Multiple errors:\n";
377 for (auto &ErrPayload : Payloads) {
378 ErrPayload->log(OS);
379 OS << "\n";
380 }
381 }
382
383 std::error_code convertToErrorCode() const override;
384
385 // Used by ErrorInfo::classID.
386 static char ID;
387
388private:
389 ErrorList(std::unique_ptr<ErrorInfoBase> Payload1,
390 std::unique_ptr<ErrorInfoBase> Payload2) {
391 assert(!Payload1->isA<ErrorList>() && !Payload2->isA<ErrorList>() &&((void)0)
392 "ErrorList constructor payloads should be singleton errors")((void)0);
393 Payloads.push_back(std::move(Payload1));
394 Payloads.push_back(std::move(Payload2));
395 }
396
397 static Error join(Error E1, Error E2) {
398 if (!E1)
399 return E2;
400 if (!E2)
401 return E1;
402 if (E1.isA<ErrorList>()) {
403 auto &E1List = static_cast<ErrorList &>(*E1.getPtr());
404 if (E2.isA<ErrorList>()) {
405 auto E2Payload = E2.takePayload();
406 auto &E2List = static_cast<ErrorList &>(*E2Payload);
407 for (auto &Payload : E2List.Payloads)
408 E1List.Payloads.push_back(std::move(Payload));
409 } else
410 E1List.Payloads.push_back(E2.takePayload());
411
412 return E1;
413 }
414 if (E2.isA<ErrorList>()) {
415 auto &E2List = static_cast<ErrorList &>(*E2.getPtr());
416 E2List.Payloads.insert(E2List.Payloads.begin(), E1.takePayload());
417 return E2;
418 }
419 return Error(std::unique_ptr<ErrorList>(
420 new ErrorList(E1.takePayload(), E2.takePayload())));
421 }
422
423 std::vector<std::unique_ptr<ErrorInfoBase>> Payloads;
424};
425
426/// Concatenate errors. The resulting Error is unchecked, and contains the
427/// ErrorInfo(s), if any, contained in E1, followed by the
428/// ErrorInfo(s), if any, contained in E2.
429inline Error joinErrors(Error E1, Error E2) {
430 return ErrorList::join(std::move(E1), std::move(E2));
431}
432
433/// Tagged union holding either a T or a Error.
434///
435/// This class parallels ErrorOr, but replaces error_code with Error. Since
436/// Error cannot be copied, this class replaces getError() with
437/// takeError(). It also adds an bool errorIsA<ErrT>() method for testing the
438/// error class type.
439///
440/// Example usage of 'Expected<T>' as a function return type:
441///
442/// @code{.cpp}
443/// Expected<int> myDivide(int A, int B) {
444/// if (B == 0) {
445/// // return an Error
446/// return createStringError(inconvertibleErrorCode(),
447/// "B must not be zero!");
448/// }
449/// // return an integer
450/// return A / B;
451/// }
452/// @endcode
453///
454/// Checking the results of to a function returning 'Expected<T>':
455/// @code{.cpp}
456/// if (auto E = Result.takeError()) {
457/// // We must consume the error. Typically one of:
458/// // - return the error to our caller
459/// // - toString(), when logging
460/// // - consumeError(), to silently swallow the error
461/// // - handleErrors(), to distinguish error types
462/// errs() << "Problem with division " << toString(std::move(E)) << "\n";
463/// return;
464/// }
465/// // use the result
466/// outs() << "The answer is " << *Result << "\n";
467/// @endcode
468///
469/// For unit-testing a function returning an 'Expceted<T>', see the
470/// 'EXPECT_THAT_EXPECTED' macros in llvm/Testing/Support/Error.h
471
472template <class T> class LLVM_NODISCARD[[clang::warn_unused_result]] Expected {
473 template <class T1> friend class ExpectedAsOutParameter;
474 template <class OtherT> friend class Expected;
475
476 static constexpr bool isRef = std::is_reference<T>::value;
477
478 using wrap = std::reference_wrapper<std::remove_reference_t<T>>;
479
480 using error_type = std::unique_ptr<ErrorInfoBase>;
481
482public:
483 using storage_type = std::conditional_t<isRef, wrap, T>;
484 using value_type = T;
485
486private:
487 using reference = std::remove_reference_t<T> &;
488 using const_reference = const std::remove_reference_t<T> &;
489 using pointer = std::remove_reference_t<T> *;
490 using const_pointer = const std::remove_reference_t<T> *;
491
492public:
493 /// Create an Expected<T> error value from the given Error.
494 Expected(Error Err)
495 : HasError(true)
496#if LLVM_ENABLE_ABI_BREAKING_CHECKS0
497 // Expected is unchecked upon construction in Debug builds.
498 , Unchecked(true)
499#endif
500 {
501 assert(Err && "Cannot create Expected<T> from Error success value.")((void)0);
502 new (getErrorStorage()) error_type(Err.takePayload());
503 }
504
505 /// Forbid to convert from Error::success() implicitly, this avoids having
506 /// Expected<T> foo() { return Error::success(); } which compiles otherwise
507 /// but triggers the assertion above.
508 Expected(ErrorSuccess) = delete;
509
510 /// Create an Expected<T> success value from the given OtherT value, which
511 /// must be convertible to T.
512 template <typename OtherT>
513 Expected(OtherT &&Val,
514 std::enable_if_t<std::is_convertible<OtherT, T>::value> * = nullptr)
515 : HasError(false)
516#if LLVM_ENABLE_ABI_BREAKING_CHECKS0
517 // Expected is unchecked upon construction in Debug builds.
518 ,
519 Unchecked(true)
520#endif
521 {
522 new (getStorage()) storage_type(std::forward<OtherT>(Val));
523 }
524
525 /// Move construct an Expected<T> value.
526 Expected(Expected &&Other) { moveConstruct(std::move(Other)); }
527
528 /// Move construct an Expected<T> value from an Expected<OtherT>, where OtherT
529 /// must be convertible to T.
530 template <class OtherT>
531 Expected(
532 Expected<OtherT> &&Other,
533 std::enable_if_t<std::is_convertible<OtherT, T>::value> * = nullptr) {
534 moveConstruct(std::move(Other));
535 }
536
537 /// Move construct an Expected<T> value from an Expected<OtherT>, where OtherT
538 /// isn't convertible to T.
539 template <class OtherT>
540 explicit Expected(
541 Expected<OtherT> &&Other,
542 std::enable_if_t<!std::is_convertible<OtherT, T>::value> * = nullptr) {
543 moveConstruct(std::move(Other));
544 }
545
546 /// Move-assign from another Expected<T>.
547 Expected &operator=(Expected &&Other) {
548 moveAssign(std::move(Other));
549 return *this;
550 }
551
552 /// Destroy an Expected<T>.
553 ~Expected() {
554 assertIsChecked();
555 if (!HasError)
556 getStorage()->~storage_type();
557 else
558 getErrorStorage()->~error_type();
559 }
560
561 /// Return false if there is an error.
562 explicit operator bool() {
563#if LLVM_ENABLE_ABI_BREAKING_CHECKS0
564 Unchecked = HasError;
565#endif
566 return !HasError;
567 }
568
569 /// Returns a reference to the stored T value.
570 reference get() {
571 assertIsChecked();
572 return *getStorage();
573 }
574
575 /// Returns a const reference to the stored T value.
576 const_reference get() const {
577 assertIsChecked();
578 return const_cast<Expected<T> *>(this)->get();
579 }
580
581 /// Check that this Expected<T> is an error of type ErrT.
582 template <typename ErrT> bool errorIsA() const {
583 return HasError && (*getErrorStorage())->template isA<ErrT>();
584 }
585
586 /// Take ownership of the stored error.
587 /// After calling this the Expected<T> is in an indeterminate state that can
588 /// only be safely destructed. No further calls (beside the destructor) should
589 /// be made on the Expected<T> value.
590 Error takeError() {
591#if LLVM_ENABLE_ABI_BREAKING_CHECKS0
592 Unchecked = false;
593#endif
594 return HasError ? Error(std::move(*getErrorStorage())) : Error::success();
595 }
596
597 /// Returns a pointer to the stored T value.
598 pointer operator->() {
599 assertIsChecked();
600 return toPointer(getStorage());
601 }
602
603 /// Returns a const pointer to the stored T value.
604 const_pointer operator->() const {
605 assertIsChecked();
606 return toPointer(getStorage());
607 }
608
609 /// Returns a reference to the stored T value.
610 reference operator*() {
611 assertIsChecked();
612 return *getStorage();
613 }
614
615 /// Returns a const reference to the stored T value.
616 const_reference operator*() const {
617 assertIsChecked();
618 return *getStorage();
619 }
620
621private:
622 template <class T1>
623 static bool compareThisIfSameType(const T1 &a, const T1 &b) {
624 return &a == &b;
625 }
626
627 template <class T1, class T2>
628 static bool compareThisIfSameType(const T1 &, const T2 &) {
629 return false;
630 }
631
632 template <class OtherT> void moveConstruct(Expected<OtherT> &&Other) {
633 HasError = Other.HasError;
634#if LLVM_ENABLE_ABI_BREAKING_CHECKS0
635 Unchecked = true;
636 Other.Unchecked = false;
637#endif
638
639 if (!HasError)
640 new (getStorage()) storage_type(std::move(*Other.getStorage()));
641 else
642 new (getErrorStorage()) error_type(std::move(*Other.getErrorStorage()));
643 }
644
645 template <class OtherT> void moveAssign(Expected<OtherT> &&Other) {
646 assertIsChecked();
647
648 if (compareThisIfSameType(*this, Other))
649 return;
650
651 this->~Expected();
652 new (this) Expected(std::move(Other));
653 }
654
655 pointer toPointer(pointer Val) { return Val; }
656
657 const_pointer toPointer(const_pointer Val) const { return Val; }
658
659 pointer toPointer(wrap *Val) { return &Val->get(); }
660
661 const_pointer toPointer(const wrap *Val) const { return &Val->get(); }
662
663 storage_type *getStorage() {
664 assert(!HasError && "Cannot get value when an error exists!")((void)0);
665 return reinterpret_cast<storage_type *>(&TStorage);
666 }
667
668 const storage_type *getStorage() const {
669 assert(!HasError && "Cannot get value when an error exists!")((void)0);
670 return reinterpret_cast<const storage_type *>(&TStorage);
671 }
672
673 error_type *getErrorStorage() {
674 assert(HasError && "Cannot get error when a value exists!")((void)0);
675 return reinterpret_cast<error_type *>(&ErrorStorage);
676 }
677
678 const error_type *getErrorStorage() const {
679 assert(HasError && "Cannot get error when a value exists!")((void)0);
680 return reinterpret_cast<const error_type *>(&ErrorStorage);
681 }
682
683 // Used by ExpectedAsOutParameter to reset the checked flag.
684 void setUnchecked() {
685#if LLVM_ENABLE_ABI_BREAKING_CHECKS0
686 Unchecked = true;
687#endif
688 }
689
690#if LLVM_ENABLE_ABI_BREAKING_CHECKS0
691 LLVM_ATTRIBUTE_NORETURN__attribute__((noreturn))
692 LLVM_ATTRIBUTE_NOINLINE__attribute__((noinline))
693 void fatalUncheckedExpected() const {
694 dbgs() << "Expected<T> must be checked before access or destruction.\n";
695 if (HasError) {
696 dbgs() << "Unchecked Expected<T> contained error:\n";
697 (*getErrorStorage())->log(dbgs());
698 } else
699 dbgs() << "Expected<T> value was in success state. (Note: Expected<T> "
700 "values in success mode must still be checked prior to being "
701 "destroyed).\n";
702 abort();
703 }
704#endif
705
706 void assertIsChecked() const {
707#if LLVM_ENABLE_ABI_BREAKING_CHECKS0
708 if (LLVM_UNLIKELY(Unchecked)__builtin_expect((bool)(Unchecked), false))
709 fatalUncheckedExpected();
710#endif
711 }
712
713 union {
714 AlignedCharArrayUnion<storage_type> TStorage;
715 AlignedCharArrayUnion<error_type> ErrorStorage;
716 };
717 bool HasError : 1;
718#if LLVM_ENABLE_ABI_BREAKING_CHECKS0
719 bool Unchecked : 1;
720#endif
721};
722
723/// Report a serious error, calling any installed error handler. See
724/// ErrorHandling.h.
725LLVM_ATTRIBUTE_NORETURN__attribute__((noreturn)) void report_fatal_error(Error Err,
726 bool gen_crash_diag = true);
727
728/// Report a fatal error if Err is a failure value.
729///
730/// This function can be used to wrap calls to fallible functions ONLY when it
731/// is known that the Error will always be a success value. E.g.
732///
733/// @code{.cpp}
734/// // foo only attempts the fallible operation if DoFallibleOperation is
735/// // true. If DoFallibleOperation is false then foo always returns
736/// // Error::success().
737/// Error foo(bool DoFallibleOperation);
738///
739/// cantFail(foo(false));
740/// @endcode
741inline void cantFail(Error Err, const char *Msg = nullptr) {
742 if (Err) {
743 if (!Msg)
744 Msg = "Failure value returned from cantFail wrapped call";
745#ifndef NDEBUG1
746 std::string Str;
747 raw_string_ostream OS(Str);
748 OS << Msg << "\n" << Err;
749 Msg = OS.str().c_str();
750#endif
751 llvm_unreachable(Msg)__builtin_unreachable();
752 }
753}
754
755/// Report a fatal error if ValOrErr is a failure value, otherwise unwraps and
756/// returns the contained value.
757///
758/// This function can be used to wrap calls to fallible functions ONLY when it
759/// is known that the Error will always be a success value. E.g.
760///
761/// @code{.cpp}
762/// // foo only attempts the fallible operation if DoFallibleOperation is
763/// // true. If DoFallibleOperation is false then foo always returns an int.
764/// Expected<int> foo(bool DoFallibleOperation);
765///
766/// int X = cantFail(foo(false));
767/// @endcode
768template <typename T>
769T cantFail(Expected<T> ValOrErr, const char *Msg = nullptr) {
770 if (ValOrErr)
771 return std::move(*ValOrErr);
772 else {
773 if (!Msg)
774 Msg = "Failure value returned from cantFail wrapped call";
775#ifndef NDEBUG1
776 std::string Str;
777 raw_string_ostream OS(Str);
778 auto E = ValOrErr.takeError();
779 OS << Msg << "\n" << E;
780 Msg = OS.str().c_str();
781#endif
782 llvm_unreachable(Msg)__builtin_unreachable();
783 }
784}
785
786/// Report a fatal error if ValOrErr is a failure value, otherwise unwraps and
787/// returns the contained reference.
788///
789/// This function can be used to wrap calls to fallible functions ONLY when it
790/// is known that the Error will always be a success value. E.g.
791///
792/// @code{.cpp}
793/// // foo only attempts the fallible operation if DoFallibleOperation is
794/// // true. If DoFallibleOperation is false then foo always returns a Bar&.
795/// Expected<Bar&> foo(bool DoFallibleOperation);
796///
797/// Bar &X = cantFail(foo(false));
798/// @endcode
799template <typename T>
800T& cantFail(Expected<T&> ValOrErr, const char *Msg = nullptr) {
801 if (ValOrErr)
802 return *ValOrErr;
803 else {
804 if (!Msg)
805 Msg = "Failure value returned from cantFail wrapped call";
806#ifndef NDEBUG1
807 std::string Str;
808 raw_string_ostream OS(Str);
809 auto E = ValOrErr.takeError();
810 OS << Msg << "\n" << E;
811 Msg = OS.str().c_str();
812#endif
813 llvm_unreachable(Msg)__builtin_unreachable();
814 }
815}
816
817/// Helper for testing applicability of, and applying, handlers for
818/// ErrorInfo types.
819template <typename HandlerT>
820class ErrorHandlerTraits
821 : public ErrorHandlerTraits<decltype(
822 &std::remove_reference<HandlerT>::type::operator())> {};
823
824// Specialization functions of the form 'Error (const ErrT&)'.
825template <typename ErrT> class ErrorHandlerTraits<Error (&)(ErrT &)> {
826public:
827 static bool appliesTo(const ErrorInfoBase &E) {
828 return E.template isA<ErrT>();
829 }
830
831 template <typename HandlerT>
832 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
833 assert(appliesTo(*E) && "Applying incorrect handler")((void)0);
834 return H(static_cast<ErrT &>(*E));
835 }
836};
837
838// Specialization functions of the form 'void (const ErrT&)'.
839template <typename ErrT> class ErrorHandlerTraits<void (&)(ErrT &)> {
840public:
841 static bool appliesTo(const ErrorInfoBase &E) {
842 return E.template isA<ErrT>();
843 }
844
845 template <typename HandlerT>
846 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
847 assert(appliesTo(*E) && "Applying incorrect handler")((void)0);
848 H(static_cast<ErrT &>(*E));
849 return Error::success();
850 }
851};
852
853/// Specialization for functions of the form 'Error (std::unique_ptr<ErrT>)'.
854template <typename ErrT>
855class ErrorHandlerTraits<Error (&)(std::unique_ptr<ErrT>)> {
856public:
857 static bool appliesTo(const ErrorInfoBase &E) {
858 return E.template isA<ErrT>();
859 }
860
861 template <typename HandlerT>
862 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
863 assert(appliesTo(*E) && "Applying incorrect handler")((void)0);
864 std::unique_ptr<ErrT> SubE(static_cast<ErrT *>(E.release()));
865 return H(std::move(SubE));
866 }
867};
868
869/// Specialization for functions of the form 'void (std::unique_ptr<ErrT>)'.
870template <typename ErrT>
871class ErrorHandlerTraits<void (&)(std::unique_ptr<ErrT>)> {
872public:
873 static bool appliesTo(const ErrorInfoBase &E) {
874 return E.template isA<ErrT>();
875 }
876
877 template <typename HandlerT>
878 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
879 assert(appliesTo(*E) && "Applying incorrect handler")((void)0);
880 std::unique_ptr<ErrT> SubE(static_cast<ErrT *>(E.release()));
881 H(std::move(SubE));
882 return Error::success();
883 }
884};
885
886// Specialization for member functions of the form 'RetT (const ErrT&)'.
887template <typename C, typename RetT, typename ErrT>
888class ErrorHandlerTraits<RetT (C::*)(ErrT &)>
889 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
890
891// Specialization for member functions of the form 'RetT (const ErrT&) const'.
892template <typename C, typename RetT, typename ErrT>
893class ErrorHandlerTraits<RetT (C::*)(ErrT &) const>
894 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
895
896// Specialization for member functions of the form 'RetT (const ErrT&)'.
897template <typename C, typename RetT, typename ErrT>
898class ErrorHandlerTraits<RetT (C::*)(const ErrT &)>
899 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
900
901// Specialization for member functions of the form 'RetT (const ErrT&) const'.
902template <typename C, typename RetT, typename ErrT>
903class ErrorHandlerTraits<RetT (C::*)(const ErrT &) const>
904 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
905
906/// Specialization for member functions of the form
907/// 'RetT (std::unique_ptr<ErrT>)'.
908template <typename C, typename RetT, typename ErrT>
909class ErrorHandlerTraits<RetT (C::*)(std::unique_ptr<ErrT>)>
910 : public ErrorHandlerTraits<RetT (&)(std::unique_ptr<ErrT>)> {};
911
912/// Specialization for member functions of the form
913/// 'RetT (std::unique_ptr<ErrT>) const'.
914template <typename C, typename RetT, typename ErrT>
915class ErrorHandlerTraits<RetT (C::*)(std::unique_ptr<ErrT>) const>
916 : public ErrorHandlerTraits<RetT (&)(std::unique_ptr<ErrT>)> {};
917
918inline Error handleErrorImpl(std::unique_ptr<ErrorInfoBase> Payload) {
919 return Error(std::move(Payload));
920}
921
922template <typename HandlerT, typename... HandlerTs>
923Error handleErrorImpl(std::unique_ptr<ErrorInfoBase> Payload,
924 HandlerT &&Handler, HandlerTs &&... Handlers) {
925 if (ErrorHandlerTraits<HandlerT>::appliesTo(*Payload))
926 return ErrorHandlerTraits<HandlerT>::apply(std::forward<HandlerT>(Handler),
927 std::move(Payload));
928 return handleErrorImpl(std::move(Payload),
929 std::forward<HandlerTs>(Handlers)...);
930}
931
932/// Pass the ErrorInfo(s) contained in E to their respective handlers. Any
933/// unhandled errors (or Errors returned by handlers) are re-concatenated and
934/// returned.
935/// Because this function returns an error, its result must also be checked
936/// or returned. If you intend to handle all errors use handleAllErrors
937/// (which returns void, and will abort() on unhandled errors) instead.
938template <typename... HandlerTs>
939Error handleErrors(Error E, HandlerTs &&... Hs) {
940 if (!E)
941 return Error::success();
942
943 std::unique_ptr<ErrorInfoBase> Payload = E.takePayload();
944
945 if (Payload->isA<ErrorList>()) {
946 ErrorList &List = static_cast<ErrorList &>(*Payload);
947 Error R;
948 for (auto &P : List.Payloads)
949 R = ErrorList::join(
950 std::move(R),
951 handleErrorImpl(std::move(P), std::forward<HandlerTs>(Hs)...));
952 return R;
953 }
954
955 return handleErrorImpl(std::move(Payload), std::forward<HandlerTs>(Hs)...);
956}
957
958/// Behaves the same as handleErrors, except that by contract all errors
959/// *must* be handled by the given handlers (i.e. there must be no remaining
960/// errors after running the handlers, or llvm_unreachable is called).
961template <typename... HandlerTs>
962void handleAllErrors(Error E, HandlerTs &&... Handlers) {
963 cantFail(handleErrors(std::move(E), std::forward<HandlerTs>(Handlers)...));
964}
965
966/// Check that E is a non-error, then drop it.
967/// If E is an error, llvm_unreachable will be called.
968inline void handleAllErrors(Error E) {
969 cantFail(std::move(E));
970}
971
972/// Handle any errors (if present) in an Expected<T>, then try a recovery path.
973///
974/// If the incoming value is a success value it is returned unmodified. If it
975/// is a failure value then it the contained error is passed to handleErrors.
976/// If handleErrors is able to handle the error then the RecoveryPath functor
977/// is called to supply the final result. If handleErrors is not able to
978/// handle all errors then the unhandled errors are returned.
979///
980/// This utility enables the follow pattern:
981///
982/// @code{.cpp}
983/// enum FooStrategy { Aggressive, Conservative };
984/// Expected<Foo> foo(FooStrategy S);
985///
986/// auto ResultOrErr =
987/// handleExpected(
988/// foo(Aggressive),
989/// []() { return foo(Conservative); },
990/// [](AggressiveStrategyError&) {
991/// // Implicitly conusme this - we'll recover by using a conservative
992/// // strategy.
993/// });
994///
995/// @endcode
996template <typename T, typename RecoveryFtor, typename... HandlerTs>
997Expected<T> handleExpected(Expected<T> ValOrErr, RecoveryFtor &&RecoveryPath,
998 HandlerTs &&... Handlers) {
999 if (ValOrErr)
1000 return ValOrErr;
1001
1002 if (auto Err = handleErrors(ValOrErr.takeError(),
1003 std::forward<HandlerTs>(Handlers)...))
1004 return std::move(Err);
1005
1006 return RecoveryPath();
1007}
1008
1009/// Log all errors (if any) in E to OS. If there are any errors, ErrorBanner
1010/// will be printed before the first one is logged. A newline will be printed
1011/// after each error.
1012///
1013/// This function is compatible with the helpers from Support/WithColor.h. You
1014/// can pass any of them as the OS. Please consider using them instead of
1015/// including 'error: ' in the ErrorBanner.
1016///
1017/// This is useful in the base level of your program to allow clean termination
1018/// (allowing clean deallocation of resources, etc.), while reporting error
1019/// information to the user.
1020void logAllUnhandledErrors(Error E, raw_ostream &OS, Twine ErrorBanner = {});
1021
1022/// Write all error messages (if any) in E to a string. The newline character
1023/// is used to separate error messages.
1024inline std::string toString(Error E) {
1025 SmallVector<std::string, 2> Errors;
1026 handleAllErrors(std::move(E), [&Errors](const ErrorInfoBase &EI) {
1027 Errors.push_back(EI.message());
1028 });
1029 return join(Errors.begin(), Errors.end(), "\n");
1030}
1031
1032/// Consume a Error without doing anything. This method should be used
1033/// only where an error can be considered a reasonable and expected return
1034/// value.
1035///
1036/// Uses of this method are potentially indicative of design problems: If it's
1037/// legitimate to do nothing while processing an "error", the error-producer
1038/// might be more clearly refactored to return an Optional<T>.
1039inline void consumeError(Error Err) {
1040 handleAllErrors(std::move(Err), [](const ErrorInfoBase &) {});
1041}
1042
1043/// Convert an Expected to an Optional without doing anything. This method
1044/// should be used only where an error can be considered a reasonable and
1045/// expected return value.
1046///
1047/// Uses of this method are potentially indicative of problems: perhaps the
1048/// error should be propagated further, or the error-producer should just
1049/// return an Optional in the first place.
1050template <typename T> Optional<T> expectedToOptional(Expected<T> &&E) {
1051 if (E)
1052 return std::move(*E);
1053 consumeError(E.takeError());
1054 return None;
1055}
1056
1057/// Helper for converting an Error to a bool.
1058///
1059/// This method returns true if Err is in an error state, or false if it is
1060/// in a success state. Puts Err in a checked state in both cases (unlike
1061/// Error::operator bool(), which only does this for success states).
1062inline bool errorToBool(Error Err) {
1063 bool IsError = static_cast<bool>(Err);
1064 if (IsError)
1065 consumeError(std::move(Err));
1066 return IsError;
1067}
1068
1069/// Helper for Errors used as out-parameters.
1070///
1071/// This helper is for use with the Error-as-out-parameter idiom, where an error
1072/// is passed to a function or method by reference, rather than being returned.
1073/// In such cases it is helpful to set the checked bit on entry to the function
1074/// so that the error can be written to (unchecked Errors abort on assignment)
1075/// and clear the checked bit on exit so that clients cannot accidentally forget
1076/// to check the result. This helper performs these actions automatically using
1077/// RAII:
1078///
1079/// @code{.cpp}
1080/// Result foo(Error &Err) {
1081/// ErrorAsOutParameter ErrAsOutParam(&Err); // 'Checked' flag set
1082/// // <body of foo>
1083/// // <- 'Checked' flag auto-cleared when ErrAsOutParam is destructed.
1084/// }
1085/// @endcode
1086///
1087/// ErrorAsOutParameter takes an Error* rather than Error& so that it can be
1088/// used with optional Errors (Error pointers that are allowed to be null). If
1089/// ErrorAsOutParameter took an Error reference, an instance would have to be
1090/// created inside every condition that verified that Error was non-null. By
1091/// taking an Error pointer we can just create one instance at the top of the
1092/// function.
1093class ErrorAsOutParameter {
1094public:
1095 ErrorAsOutParameter(Error *Err) : Err(Err) {
1096 // Raise the checked bit if Err is success.
1097 if (Err)
1098 (void)!!*Err;
1099 }
1100
1101 ~ErrorAsOutParameter() {
1102 // Clear the checked bit.
1103 if (Err && !*Err)
1104 *Err = Error::success();
1105 }
1106
1107private:
1108 Error *Err;
1109};
1110
1111/// Helper for Expected<T>s used as out-parameters.
1112///
1113/// See ErrorAsOutParameter.
1114template <typename T>
1115class ExpectedAsOutParameter {
1116public:
1117 ExpectedAsOutParameter(Expected<T> *ValOrErr)
1118 : ValOrErr(ValOrErr) {
1119 if (ValOrErr)
1120 (void)!!*ValOrErr;
1121 }
1122
1123 ~ExpectedAsOutParameter() {
1124 if (ValOrErr)
1125 ValOrErr->setUnchecked();
1126 }
1127
1128private:
1129 Expected<T> *ValOrErr;
1130};
1131
1132/// This class wraps a std::error_code in a Error.
1133///
1134/// This is useful if you're writing an interface that returns a Error
1135/// (or Expected) and you want to call code that still returns
1136/// std::error_codes.
1137class ECError : public ErrorInfo<ECError> {
1138 friend Error errorCodeToError(std::error_code);
1139
1140 virtual void anchor() override;
1141
1142public:
1143 void setErrorCode(std::error_code EC) { this->EC = EC; }
1144 std::error_code convertToErrorCode() const override { return EC; }
1145 void log(raw_ostream &OS) const override { OS << EC.message(); }
1146
1147 // Used by ErrorInfo::classID.
1148 static char ID;
1149
1150protected:
1151 ECError() = default;
1152 ECError(std::error_code EC) : EC(EC) {}
1153
1154 std::error_code EC;
1155};
1156
1157/// The value returned by this function can be returned from convertToErrorCode
1158/// for Error values where no sensible translation to std::error_code exists.
1159/// It should only be used in this situation, and should never be used where a
1160/// sensible conversion to std::error_code is available, as attempts to convert
1161/// to/from this error will result in a fatal error. (i.e. it is a programmatic
1162///error to try to convert such a value).
1163std::error_code inconvertibleErrorCode();
1164
1165/// Helper for converting an std::error_code to a Error.
1166Error errorCodeToError(std::error_code EC);
1167
1168/// Helper for converting an ECError to a std::error_code.
1169///
1170/// This method requires that Err be Error() or an ECError, otherwise it
1171/// will trigger a call to abort().
1172std::error_code errorToErrorCode(Error Err);
1173
1174/// Convert an ErrorOr<T> to an Expected<T>.
1175template <typename T> Expected<T> errorOrToExpected(ErrorOr<T> &&EO) {
1176 if (auto EC = EO.getError())
1177 return errorCodeToError(EC);
1178 return std::move(*EO);
1179}
1180
1181/// Convert an Expected<T> to an ErrorOr<T>.
1182template <typename T> ErrorOr<T> expectedToErrorOr(Expected<T> &&E) {
1183 if (auto Err = E.takeError())
1184 return errorToErrorCode(std::move(Err));
1185 return std::move(*E);
1186}
1187
1188/// This class wraps a string in an Error.
1189///
1190/// StringError is useful in cases where the client is not expected to be able
1191/// to consume the specific error message programmatically (for example, if the
1192/// error message is to be presented to the user).
1193///
1194/// StringError can also be used when additional information is to be printed
1195/// along with a error_code message. Depending on the constructor called, this
1196/// class can either display:
1197/// 1. the error_code message (ECError behavior)
1198/// 2. a string
1199/// 3. the error_code message and a string
1200///
1201/// These behaviors are useful when subtyping is required; for example, when a
1202/// specific library needs an explicit error type. In the example below,
1203/// PDBError is derived from StringError:
1204///
1205/// @code{.cpp}
1206/// Expected<int> foo() {
1207/// return llvm::make_error<PDBError>(pdb_error_code::dia_failed_loading,
1208/// "Additional information");
1209/// }
1210/// @endcode
1211///
1212class StringError : public ErrorInfo<StringError> {
1213public:
1214 static char ID;
1215
1216 // Prints EC + S and converts to EC
1217 StringError(std::error_code EC, const Twine &S = Twine());
1218
1219 // Prints S and converts to EC
1220 StringError(const Twine &S, std::error_code EC);
1221
1222 void log(raw_ostream &OS) const override;
1223 std::error_code convertToErrorCode() const override;
1224
1225 const std::string &getMessage() const { return Msg; }
1226
1227private:
1228 std::string Msg;
1229 std::error_code EC;
1230 const bool PrintMsgOnly = false;
1231};
1232
1233/// Create formatted StringError object.
1234template <typename... Ts>
1235inline Error createStringError(std::error_code EC, char const *Fmt,
1236 const Ts &... Vals) {
1237 std::string Buffer;
1238 raw_string_ostream Stream(Buffer);
1239 Stream << format(Fmt, Vals...);
1240 return make_error<StringError>(Stream.str(), EC);
1241}
1242
1243Error createStringError(std::error_code EC, char const *Msg);
1244
1245inline Error createStringError(std::error_code EC, const Twine &S) {
1246 return createStringError(EC, S.str().c_str());
1247}
1248
1249template <typename... Ts>
1250inline Error createStringError(std::errc EC, char const *Fmt,
1251 const Ts &... Vals) {
1252 return createStringError(std::make_error_code(EC), Fmt, Vals...);
1253}
1254
1255/// This class wraps a filename and another Error.
1256///
1257/// In some cases, an error needs to live along a 'source' name, in order to
1258/// show more detailed information to the user.
1259class FileError final : public ErrorInfo<FileError> {
1260
1261 friend Error createFileError(const Twine &, Error);
1262 friend Error createFileError(const Twine &, size_t, Error);
1263
1264public:
1265 void log(raw_ostream &OS) const override {
1266 assert(Err && !FileName.empty() && "Trying to log after takeError().")((void)0);
1267 OS << "'" << FileName << "': ";
1268 if (Line.hasValue())
1269 OS << "line " << Line.getValue() << ": ";
1270 Err->log(OS);
1271 }
1272
1273 StringRef getFileName() { return FileName; }
1274
1275 Error takeError() { return Error(std::move(Err)); }
1276
1277 std::error_code convertToErrorCode() const override;
1278
1279 // Used by ErrorInfo::classID.
1280 static char ID;
1281
1282private:
1283 FileError(const Twine &F, Optional<size_t> LineNum,
1284 std::unique_ptr<ErrorInfoBase> E) {
1285 assert(E && "Cannot create FileError from Error success value.")((void)0);
1286 assert(!F.isTriviallyEmpty() &&((void)0)
1287 "The file name provided to FileError must not be empty.")((void)0);
1288 FileName = F.str();
1289 Err = std::move(E);
1290 Line = std::move(LineNum);
1291 }
1292
1293 static Error build(const Twine &F, Optional<size_t> Line, Error E) {
1294 std::unique_ptr<ErrorInfoBase> Payload;
1295 handleAllErrors(std::move(E),
1296 [&](std::unique_ptr<ErrorInfoBase> EIB) -> Error {
1297 Payload = std::move(EIB);
1298 return Error::success();
1299 });
1300 return Error(
1301 std::unique_ptr<FileError>(new FileError(F, Line, std::move(Payload))));
1302 }
1303
1304 std::string FileName;
1305 Optional<size_t> Line;
1306 std::unique_ptr<ErrorInfoBase> Err;
1307};
1308
1309/// Concatenate a source file path and/or name with an Error. The resulting
1310/// Error is unchecked.
1311inline Error createFileError(const Twine &F, Error E) {
1312 return FileError::build(F, Optional<size_t>(), std::move(E));
1313}
1314
1315/// Concatenate a source file path and/or name with line number and an Error.
1316/// The resulting Error is unchecked.
1317inline Error createFileError(const Twine &F, size_t Line, Error E) {
1318 return FileError::build(F, Optional<size_t>(Line), std::move(E));
1319}
1320
1321/// Concatenate a source file path and/or name with a std::error_code
1322/// to form an Error object.
1323inline Error createFileError(const Twine &F, std::error_code EC) {
1324 return createFileError(F, errorCodeToError(EC));
1325}
1326
1327/// Concatenate a source file path and/or name with line number and
1328/// std::error_code to form an Error object.
1329inline Error createFileError(const Twine &F, size_t Line, std::error_code EC) {
1330 return createFileError(F, Line, errorCodeToError(EC));
1331}
1332
1333Error createFileError(const Twine &F, ErrorSuccess) = delete;
1334
1335/// Helper for check-and-exit error handling.
1336///
1337/// For tool use only. NOT FOR USE IN LIBRARY CODE.
1338///
1339class ExitOnError {
1340public:
1341 /// Create an error on exit helper.
1342 ExitOnError(std::string Banner = "", int DefaultErrorExitCode = 1)
1343 : Banner(std::move(Banner)),
1344 GetExitCode([=](const Error &) { return DefaultErrorExitCode; }) {}
1345
1346 /// Set the banner string for any errors caught by operator().
1347 void setBanner(std::string Banner) { this->Banner = std::move(Banner); }
1348
1349 /// Set the exit-code mapper function.
1350 void setExitCodeMapper(std::function<int(const Error &)> GetExitCode) {
1351 this->GetExitCode = std::move(GetExitCode);
1352 }
1353
1354 /// Check Err. If it's in a failure state log the error(s) and exit.
1355 void operator()(Error Err) const { checkError(std::move(Err)); }
1356
1357 /// Check E. If it's in a success state then return the contained value. If
1358 /// it's in a failure state log the error(s) and exit.
1359 template <typename T> T operator()(Expected<T> &&E) const {
1360 checkError(E.takeError());
1361 return std::move(*E);
1362 }
1363
1364 /// Check E. If it's in a success state then return the contained reference. If
1365 /// it's in a failure state log the error(s) and exit.
1366 template <typename T> T& operator()(Expected<T&> &&E) const {
1367 checkError(E.takeError());
1368 return *E;
1369 }
1370
1371private:
1372 void checkError(Error Err) const {
1373 if (Err) {
1374 int ExitCode = GetExitCode(Err);
1375 logAllUnhandledErrors(std::move(Err), errs(), Banner);
1376 exit(ExitCode);
1377 }
1378 }
1379
1380 std::string Banner;
1381 std::function<int(const Error &)> GetExitCode;
1382};
1383
1384/// Conversion from Error to LLVMErrorRef for C error bindings.
1385inline LLVMErrorRef wrap(Error Err) {
1386 return reinterpret_cast<LLVMErrorRef>(Err.takePayload().release());
1387}
1388
1389/// Conversion from LLVMErrorRef to Error for C error bindings.
1390inline Error unwrap(LLVMErrorRef ErrRef) {
1391 return Error(std::unique_ptr<ErrorInfoBase>(
1392 reinterpret_cast<ErrorInfoBase *>(ErrRef)));
1393}
1394
1395} // end namespace llvm
1396
1397#endif // LLVM_SUPPORT_ERROR_H