Bug Summary

File:src/gnu/usr.bin/clang/llvm-objdump/../../../llvm/llvm/tools/llvm-objdump/COFFDump.cpp
Warning:line 204, column 10
1st function call argument is an uninitialized value

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

/usr/src/gnu/usr.bin/clang/llvm-objdump/../../../llvm/llvm/tools/llvm-objdump/COFFDump.cpp

→
1//===-- COFFDump.cpp - COFF-specific dumper ---------------------*- 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/// \file
10/// This file implements the COFF-specific dumper for llvm-objdump.
11/// It outputs the Win64 EH data structures as plain text.
12/// The encoding of the unwind codes is described in MSDN:
13/// http://msdn.microsoft.com/en-us/library/ck9asaa9.aspx
14///
15//===----------------------------------------------------------------------===//
16
17#include "COFFDump.h"
18
19#include "llvm-objdump.h"
20#include "llvm/Demangle/Demangle.h"
21#include "llvm/Object/COFF.h"
22#include "llvm/Object/COFFImportFile.h"
23#include "llvm/Object/ObjectFile.h"
24#include "llvm/Support/Format.h"
25#include "llvm/Support/Win64EH.h"
26#include "llvm/Support/WithColor.h"
27#include "llvm/Support/raw_ostream.h"
28
29using namespace llvm;
30using namespace llvm::objdump;
31using namespace llvm::object;
32using namespace llvm::Win64EH;
33
34// Returns the name of the unwind code.
35static StringRef getUnwindCodeTypeName(uint8_t Code) {
36 switch(Code) {
37 default: llvm_unreachable("Invalid unwind code")__builtin_unreachable();
38 case UOP_PushNonVol: return "UOP_PushNonVol";
39 case UOP_AllocLarge: return "UOP_AllocLarge";
40 case UOP_AllocSmall: return "UOP_AllocSmall";
41 case UOP_SetFPReg: return "UOP_SetFPReg";
42 case UOP_SaveNonVol: return "UOP_SaveNonVol";
43 case UOP_SaveNonVolBig: return "UOP_SaveNonVolBig";
44 case UOP_SaveXMM128: return "UOP_SaveXMM128";
45 case UOP_SaveXMM128Big: return "UOP_SaveXMM128Big";
46 case UOP_PushMachFrame: return "UOP_PushMachFrame";
47 }
48}
49
50// Returns the name of a referenced register.
51static StringRef getUnwindRegisterName(uint8_t Reg) {
52 switch(Reg) {
53 default: llvm_unreachable("Invalid register")__builtin_unreachable();
54 case 0: return "RAX";
55 case 1: return "RCX";
56 case 2: return "RDX";
57 case 3: return "RBX";
58 case 4: return "RSP";
59 case 5: return "RBP";
60 case 6: return "RSI";
61 case 7: return "RDI";
62 case 8: return "R8";
63 case 9: return "R9";
64 case 10: return "R10";
65 case 11: return "R11";
66 case 12: return "R12";
67 case 13: return "R13";
68 case 14: return "R14";
69 case 15: return "R15";
70 }
71}
72
73// Calculates the number of array slots required for the unwind code.
74static unsigned getNumUsedSlots(const UnwindCode &UnwindCode) {
75 switch (UnwindCode.getUnwindOp()) {
76 default: llvm_unreachable("Invalid unwind code")__builtin_unreachable();
77 case UOP_PushNonVol:
78 case UOP_AllocSmall:
79 case UOP_SetFPReg:
80 case UOP_PushMachFrame:
81 return 1;
82 case UOP_SaveNonVol:
83 case UOP_SaveXMM128:
84 return 2;
85 case UOP_SaveNonVolBig:
86 case UOP_SaveXMM128Big:
87 return 3;
88 case UOP_AllocLarge:
89 return (UnwindCode.getOpInfo() == 0) ? 2 : 3;
90 }
91}
92
93// Prints one unwind code. Because an unwind code can occupy up to 3 slots in
94// the unwind codes array, this function requires that the correct number of
95// slots is provided.
96static void printUnwindCode(ArrayRef<UnwindCode> UCs) {
97 assert(UCs.size() >= getNumUsedSlots(UCs[0]))((void)0);
98 outs() << format(" 0x%02x: ", unsigned(UCs[0].u.CodeOffset))
99 << getUnwindCodeTypeName(UCs[0].getUnwindOp());
100 switch (UCs[0].getUnwindOp()) {
101 case UOP_PushNonVol:
102 outs() << " " << getUnwindRegisterName(UCs[0].getOpInfo());
103 break;
104 case UOP_AllocLarge:
105 if (UCs[0].getOpInfo() == 0) {
106 outs() << " " << UCs[1].FrameOffset;
107 } else {
108 outs() << " " << UCs[1].FrameOffset
109 + (static_cast<uint32_t>(UCs[2].FrameOffset) << 16);
110 }
111 break;
112 case UOP_AllocSmall:
113 outs() << " " << ((UCs[0].getOpInfo() + 1) * 8);
114 break;
115 case UOP_SetFPReg:
116 outs() << " ";
117 break;
118 case UOP_SaveNonVol:
119 outs() << " " << getUnwindRegisterName(UCs[0].getOpInfo())
120 << format(" [0x%04x]", 8 * UCs[1].FrameOffset);
121 break;
122 case UOP_SaveNonVolBig:
123 outs() << " " << getUnwindRegisterName(UCs[0].getOpInfo())
124 << format(" [0x%08x]", UCs[1].FrameOffset
125 + (static_cast<uint32_t>(UCs[2].FrameOffset) << 16));
126 break;
127 case UOP_SaveXMM128:
128 outs() << " XMM" << static_cast<uint32_t>(UCs[0].getOpInfo())
129 << format(" [0x%04x]", 16 * UCs[1].FrameOffset);
130 break;
131 case UOP_SaveXMM128Big:
132 outs() << " XMM" << UCs[0].getOpInfo()
133 << format(" [0x%08x]", UCs[1].FrameOffset
134 + (static_cast<uint32_t>(UCs[2].FrameOffset) << 16));
135 break;
136 case UOP_PushMachFrame:
137 outs() << " " << (UCs[0].getOpInfo() ? "w/o" : "w")
138 << " error code";
139 break;
140 }
141 outs() << "\n";
142}
143
144static void printAllUnwindCodes(ArrayRef<UnwindCode> UCs) {
145 for (const UnwindCode *I = UCs.begin(), *E = UCs.end(); I < E; ) {
146 unsigned UsedSlots = getNumUsedSlots(*I);
147 if (UsedSlots > UCs.size()) {
148 outs() << "Unwind data corrupted: Encountered unwind op "
149 << getUnwindCodeTypeName((*I).getUnwindOp())
150 << " which requires " << UsedSlots
151 << " slots, but only " << UCs.size()
152 << " remaining in buffer";
153 return ;
154 }
155 printUnwindCode(makeArrayRef(I, E));
156 I += UsedSlots;
157 }
158}
159
160// Given a symbol sym this functions returns the address and section of it.
161static Error resolveSectionAndAddress(const COFFObjectFile *Obj,
162 const SymbolRef &Sym,
163 const coff_section *&ResolvedSection,
164 uint64_t &ResolvedAddr) {
165 Expected<uint64_t> ResolvedAddrOrErr = Sym.getAddress();
166 if (!ResolvedAddrOrErr)
15
←
Taking true branch
→
167 return ResolvedAddrOrErr.takeError();
16
←
Returning without writing to 'ResolvedSection'
→
168 ResolvedAddr = *ResolvedAddrOrErr;
169 Expected<section_iterator> Iter = Sym.getSection();
170 if (!Iter)
171 return Iter.takeError();
172 ResolvedSection = Obj->getCOFFSection(**Iter);
173 return Error::success();
174}
175
176// Given a vector of relocations for a section and an offset into this section
177// the function returns the symbol used for the relocation at the offset.
178static Error resolveSymbol(const std::vector<RelocationRef> &Rels,
179 uint64_t Offset, SymbolRef &Sym) {
180 for (auto &R : Rels) {
181 uint64_t Ofs = R.getOffset();
182 if (Ofs == Offset) {
183 Sym = *R.getSymbol();
184 return Error::success();
185 }
186 }
187 return make_error<BinaryError>();
188}
189
190// Given a vector of relocations for a section and an offset into this section
191// the function resolves the symbol used for the relocation at the offset and
192// returns the section content and the address inside the content pointed to
193// by the symbol.
194static Error
195getSectionContents(const COFFObjectFile *Obj,
196 const std::vector<RelocationRef> &Rels, uint64_t Offset,
197 ArrayRef<uint8_t> &Contents, uint64_t &Addr) {
198 SymbolRef Sym;
199 if (Error E = resolveSymbol(Rels, Offset, Sym))
9
←
Calling 'Error::operator bool'
→
11
←
Returning from 'Error::operator bool'
→
12
←
Taking false branch
→
200 return E;
201 const coff_section *Section;
13
←
'Section' declared without an initial value
→
202 if (Error E = resolveSectionAndAddress(Obj, Sym, Section, Addr))
14
←
Calling 'resolveSectionAndAddress'
→
17
←
Returning from 'resolveSectionAndAddress'
→
18
←
Calling 'Error::operator bool'
→
21
←
Returning from 'Error::operator bool'
→
22
←
Taking false branch
→
203 return E;
204 return Obj->getSectionContents(Section, Contents);
23
←
1st function call argument is an uninitialized value
205}
206
207// Given a vector of relocations for a section and an offset into this section
208// the function returns the name of the symbol used for the relocation at the
209// offset.
210static Error resolveSymbolName(const std::vector<RelocationRef> &Rels,
211 uint64_t Offset, StringRef &Name) {
212 SymbolRef Sym;
213 if (Error EC = resolveSymbol(Rels, Offset, Sym))
214 return EC;
215 Expected<StringRef> NameOrErr = Sym.getName();
216 if (!NameOrErr)
217 return NameOrErr.takeError();
218 Name = *NameOrErr;
219 return Error::success();
220}
221
222static void printCOFFSymbolAddress(raw_ostream &Out,
223 const std::vector<RelocationRef> &Rels,
224 uint64_t Offset, uint32_t Disp) {
225 StringRef Sym;
226 if (!resolveSymbolName(Rels, Offset, Sym)) {
227 Out << Sym;
228 if (Disp > 0)
229 Out << format(" + 0x%04x", Disp);
230 } else {
231 Out << format("0x%04x", Disp);
232 }
233}
234
235static void
236printSEHTable(const COFFObjectFile *Obj, uint32_t TableVA, int Count) {
237 if (Count == 0)
238 return;
239
240 uintptr_t IntPtr = 0;
241 if (Error E = Obj->getVaPtr(TableVA, IntPtr))
242 reportError(std::move(E), Obj->getFileName());
243
244 const support::ulittle32_t *P = (const support::ulittle32_t *)IntPtr;
245 outs() << "SEH Table:";
246 for (int I = 0; I < Count; ++I)
247 outs() << format(" 0x%x", P[I] + Obj->getPE32Header()->ImageBase);
248 outs() << "\n\n";
249}
250
251template <typename T>
252static void printTLSDirectoryT(const coff_tls_directory<T> *TLSDir) {
253 size_t FormatWidth = sizeof(T) * 2;
254 outs() << "TLS directory:"
255 << "\n StartAddressOfRawData: "
256 << format_hex(TLSDir->StartAddressOfRawData, FormatWidth)
257 << "\n EndAddressOfRawData: "
258 << format_hex(TLSDir->EndAddressOfRawData, FormatWidth)
259 << "\n AddressOfIndex: "
260 << format_hex(TLSDir->AddressOfIndex, FormatWidth)
261 << "\n AddressOfCallBacks: "
262 << format_hex(TLSDir->AddressOfCallBacks, FormatWidth)
263 << "\n SizeOfZeroFill: "
264 << TLSDir->SizeOfZeroFill
265 << "\n Characteristics: "
266 << TLSDir->Characteristics
267 << "\n Alignment: "
268 << TLSDir->getAlignment()
269 << "\n\n";
270}
271
272static void printTLSDirectory(const COFFObjectFile *Obj) {
273 const pe32_header *PE32Header = Obj->getPE32Header();
274 const pe32plus_header *PE32PlusHeader = Obj->getPE32PlusHeader();
275
276 // Skip if it's not executable.
277 if (!PE32Header && !PE32PlusHeader)
278 return;
279
280 const data_directory *DataDir = Obj->getDataDirectory(COFF::TLS_TABLE);
281 if (!DataDir)
282 reportError("missing data dir for TLS table", Obj->getFileName());
283
284 if (DataDir->RelativeVirtualAddress == 0)
285 return;
286
287 uintptr_t IntPtr = 0;
288 if (Error E =
289 Obj->getRvaPtr(DataDir->RelativeVirtualAddress, IntPtr))
290 reportError(std::move(E), Obj->getFileName());
291
292 if (PE32Header) {
293 auto *TLSDir = reinterpret_cast<const coff_tls_directory32 *>(IntPtr);
294 printTLSDirectoryT(TLSDir);
295 } else {
296 auto *TLSDir = reinterpret_cast<const coff_tls_directory64 *>(IntPtr);
297 printTLSDirectoryT(TLSDir);
298 }
299
300 outs() << "\n";
301}
302
303static void printLoadConfiguration(const COFFObjectFile *Obj) {
304 // Skip if it's not executable.
305 if (!Obj->getPE32Header())
306 return;
307
308 // Currently only x86 is supported
309 if (Obj->getMachine() != COFF::IMAGE_FILE_MACHINE_I386)
310 return;
311
312 const data_directory *DataDir = Obj->getDataDirectory(COFF::LOAD_CONFIG_TABLE);
313 if (!DataDir)
314 reportError("no load config data dir", Obj->getFileName());
315
316 uintptr_t IntPtr = 0;
317 if (DataDir->RelativeVirtualAddress == 0)
318 return;
319
320 if (Error E =
321 Obj->getRvaPtr(DataDir->RelativeVirtualAddress, IntPtr))
322 reportError(std::move(E), Obj->getFileName());
323
324 auto *LoadConf = reinterpret_cast<const coff_load_configuration32 *>(IntPtr);
325 outs() << "Load configuration:"
326 << "\n Timestamp: " << LoadConf->TimeDateStamp
327 << "\n Major Version: " << LoadConf->MajorVersion
328 << "\n Minor Version: " << LoadConf->MinorVersion
329 << "\n GlobalFlags Clear: " << LoadConf->GlobalFlagsClear
330 << "\n GlobalFlags Set: " << LoadConf->GlobalFlagsSet
331 << "\n Critical Section Default Timeout: " << LoadConf->CriticalSectionDefaultTimeout
332 << "\n Decommit Free Block Threshold: " << LoadConf->DeCommitFreeBlockThreshold
333 << "\n Decommit Total Free Threshold: " << LoadConf->DeCommitTotalFreeThreshold
334 << "\n Lock Prefix Table: " << LoadConf->LockPrefixTable
335 << "\n Maximum Allocation Size: " << LoadConf->MaximumAllocationSize
336 << "\n Virtual Memory Threshold: " << LoadConf->VirtualMemoryThreshold
337 << "\n Process Affinity Mask: " << LoadConf->ProcessAffinityMask
338 << "\n Process Heap Flags: " << LoadConf->ProcessHeapFlags
339 << "\n CSD Version: " << LoadConf->CSDVersion
340 << "\n Security Cookie: " << LoadConf->SecurityCookie
341 << "\n SEH Table: " << LoadConf->SEHandlerTable
342 << "\n SEH Count: " << LoadConf->SEHandlerCount
343 << "\n\n";
344 printSEHTable(Obj, LoadConf->SEHandlerTable, LoadConf->SEHandlerCount);
345 outs() << "\n";
346}
347
348// Prints import tables. The import table is a table containing the list of
349// DLL name and symbol names which will be linked by the loader.
350static void printImportTables(const COFFObjectFile *Obj) {
351 import_directory_iterator I = Obj->import_directory_begin();
352 import_directory_iterator E = Obj->import_directory_end();
353 if (I == E)
354 return;
355 outs() << "The Import Tables:\n";
356 for (const ImportDirectoryEntryRef &DirRef : Obj->import_directories()) {
357 const coff_import_directory_table_entry *Dir;
358 StringRef Name;
359 if (DirRef.getImportTableEntry(Dir)) return;
360 if (DirRef.getName(Name)) return;
361
362 outs() << format(" lookup %08x time %08x fwd %08x name %08x addr %08x\n\n",
363 static_cast<uint32_t>(Dir->ImportLookupTableRVA),
364 static_cast<uint32_t>(Dir->TimeDateStamp),
365 static_cast<uint32_t>(Dir->ForwarderChain),
366 static_cast<uint32_t>(Dir->NameRVA),
367 static_cast<uint32_t>(Dir->ImportAddressTableRVA));
368 outs() << " DLL Name: " << Name << "\n";
369 outs() << " Hint/Ord Name\n";
370 for (const ImportedSymbolRef &Entry : DirRef.imported_symbols()) {
371 bool IsOrdinal;
372 if (Entry.isOrdinal(IsOrdinal))
373 return;
374 if (IsOrdinal) {
375 uint16_t Ordinal;
376 if (Entry.getOrdinal(Ordinal))
377 return;
378 outs() << format(" % 6d\n", Ordinal);
379 continue;
380 }
381 uint32_t HintNameRVA;
382 if (Entry.getHintNameRVA(HintNameRVA))
383 return;
384 uint16_t Hint;
385 StringRef Name;
386 if (Obj->getHintName(HintNameRVA, Hint, Name))
387 return;
388 outs() << format(" % 6d ", Hint) << Name << "\n";
389 }
390 outs() << "\n";
391 }
392}
393
394// Prints export tables. The export table is a table containing the list of
395// exported symbol from the DLL.
396static void printExportTable(const COFFObjectFile *Obj) {
397 outs() << "Export Table:\n";
398 export_directory_iterator I = Obj->export_directory_begin();
399 export_directory_iterator E = Obj->export_directory_end();
400 if (I == E)
401 return;
402 StringRef DllName;
403 uint32_t OrdinalBase;
404 if (I->getDllName(DllName))
405 return;
406 if (I->getOrdinalBase(OrdinalBase))
407 return;
408 outs() << " DLL name: " << DllName << "\n";
409 outs() << " Ordinal base: " << OrdinalBase << "\n";
410 outs() << " Ordinal RVA Name\n";
411 for (; I != E; I = ++I) {
412 uint32_t Ordinal;
413 if (I->getOrdinal(Ordinal))
414 return;
415 uint32_t RVA;
416 if (I->getExportRVA(RVA))
417 return;
418 bool IsForwarder;
419 if (I->isForwarder(IsForwarder))
420 return;
421
422 if (IsForwarder) {
423 // Export table entries can be used to re-export symbols that
424 // this COFF file is imported from some DLLs. This is rare.
425 // In most cases IsForwarder is false.
426 outs() << format(" % 4d ", Ordinal);
427 } else {
428 outs() << format(" % 4d %# 8x", Ordinal, RVA);
429 }
430
431 StringRef Name;
432 if (I->getSymbolName(Name))
433 continue;
434 if (!Name.empty())
435 outs() << " " << Name;
436 if (IsForwarder) {
437 StringRef S;
438 if (I->getForwardTo(S))
439 return;
440 outs() << " (forwarded to " << S << ")";
441 }
442 outs() << "\n";
443 }
444}
445
446// Given the COFF object file, this function returns the relocations for .pdata
447// and the pointer to "runtime function" structs.
448static bool getPDataSection(const COFFObjectFile *Obj,
449 std::vector<RelocationRef> &Rels,
450 const RuntimeFunction *&RFStart, int &NumRFs) {
451 for (const SectionRef &Section : Obj->sections()) {
452 StringRef Name = unwrapOrError(Section.getName(), Obj->getFileName());
453 if (Name != ".pdata")
454 continue;
455
456 const coff_section *Pdata = Obj->getCOFFSection(Section);
457 append_range(Rels, Section.relocations());
458
459 // Sort relocations by address.
460 llvm::sort(Rels, isRelocAddressLess);
461
462 ArrayRef<uint8_t> Contents;
463 if (Error E = Obj->getSectionContents(Pdata, Contents))
464 reportError(std::move(E), Obj->getFileName());
465
466 if (Contents.empty())
467 continue;
468
469 RFStart = reinterpret_cast<const RuntimeFunction *>(Contents.data());
470 NumRFs = Contents.size() / sizeof(RuntimeFunction);
471 return true;
472 }
473 return false;
474}
475
476Error objdump::getCOFFRelocationValueString(const COFFObjectFile *Obj,
477 const RelocationRef &Rel,
478 SmallVectorImpl<char> &Result) {
479 symbol_iterator SymI = Rel.getSymbol();
480 Expected<StringRef> SymNameOrErr = SymI->getName();
481 if (!SymNameOrErr)
482 return SymNameOrErr.takeError();
483 StringRef SymName = *SymNameOrErr;
484 Result.append(SymName.begin(), SymName.end());
485 return Error::success();
486}
487
488static void printWin64EHUnwindInfo(const Win64EH::UnwindInfo *UI) {
489 // The casts to int are required in order to output the value as number.
490 // Without the casts the value would be interpreted as char data (which
491 // results in garbage output).
492 outs() << " Version: " << static_cast<int>(UI->getVersion()) << "\n";
493 outs() << " Flags: " << static_cast<int>(UI->getFlags());
494 if (UI->getFlags()) {
495 if (UI->getFlags() & UNW_ExceptionHandler)
496 outs() << " UNW_ExceptionHandler";
497 if (UI->getFlags() & UNW_TerminateHandler)
498 outs() << " UNW_TerminateHandler";
499 if (UI->getFlags() & UNW_ChainInfo)
500 outs() << " UNW_ChainInfo";
501 }
502 outs() << "\n";
503 outs() << " Size of prolog: " << static_cast<int>(UI->PrologSize) << "\n";
504 outs() << " Number of Codes: " << static_cast<int>(UI->NumCodes) << "\n";
505 // Maybe this should move to output of UOP_SetFPReg?
506 if (UI->getFrameRegister()) {
507 outs() << " Frame register: "
508 << getUnwindRegisterName(UI->getFrameRegister()) << "\n";
509 outs() << " Frame offset: " << 16 * UI->getFrameOffset() << "\n";
510 } else {
511 outs() << " No frame pointer used\n";
512 }
513 if (UI->getFlags() & (UNW_ExceptionHandler | UNW_TerminateHandler)) {
514 // FIXME: Output exception handler data
515 } else if (UI->getFlags() & UNW_ChainInfo) {
516 // FIXME: Output chained unwind info
517 }
518
519 if (UI->NumCodes)
520 outs() << " Unwind Codes:\n";
521
522 printAllUnwindCodes(makeArrayRef(&UI->UnwindCodes[0], UI->NumCodes));
523
524 outs() << "\n";
525 outs().flush();
526}
527
528/// Prints out the given RuntimeFunction struct for x64, assuming that Obj is
529/// pointing to an executable file.
530static void printRuntimeFunction(const COFFObjectFile *Obj,
531 const RuntimeFunction &RF) {
532 if (!RF.StartAddress)
533 return;
534 outs() << "Function Table:\n"
535 << format(" Start Address: 0x%04x\n",
536 static_cast<uint32_t>(RF.StartAddress))
537 << format(" End Address: 0x%04x\n",
538 static_cast<uint32_t>(RF.EndAddress))
539 << format(" Unwind Info Address: 0x%04x\n",
540 static_cast<uint32_t>(RF.UnwindInfoOffset));
541 uintptr_t addr;
542 if (Obj->getRvaPtr(RF.UnwindInfoOffset, addr))
543 return;
544 printWin64EHUnwindInfo(reinterpret_cast<const Win64EH::UnwindInfo *>(addr));
545}
546
547/// Prints out the given RuntimeFunction struct for x64, assuming that Obj is
548/// pointing to an object file. Unlike executable, fields in RuntimeFunction
549/// struct are filled with zeros, but instead there are relocations pointing to
550/// them so that the linker will fill targets' RVAs to the fields at link
551/// time. This function interprets the relocations to find the data to be used
552/// in the resulting executable.
553static void printRuntimeFunctionRels(const COFFObjectFile *Obj,
554 const RuntimeFunction &RF,
555 uint64_t SectionOffset,
556 const std::vector<RelocationRef> &Rels) {
557 outs() << "Function Table:\n";
558 outs() << " Start Address: ";
559 printCOFFSymbolAddress(outs(), Rels,
560 SectionOffset +
561 /*offsetof(RuntimeFunction, StartAddress)*/ 0,
562 RF.StartAddress);
563 outs() << "\n";
564
565 outs() << " End Address: ";
566 printCOFFSymbolAddress(outs(), Rels,
567 SectionOffset +
568 /*offsetof(RuntimeFunction, EndAddress)*/ 4,
569 RF.EndAddress);
570 outs() << "\n";
571
572 outs() << " Unwind Info Address: ";
573 printCOFFSymbolAddress(outs(), Rels,
574 SectionOffset +
575 /*offsetof(RuntimeFunction, UnwindInfoOffset)*/ 8,
576 RF.UnwindInfoOffset);
577 outs() << "\n";
578
579 ArrayRef<uint8_t> XContents;
580 uint64_t UnwindInfoOffset = 0;
581 if (Error E = getSectionContents(
8
←
Calling 'getSectionContents'
→
582 Obj, Rels,
583 SectionOffset +
584 /*offsetof(RuntimeFunction, UnwindInfoOffset)*/ 8,
585 XContents, UnwindInfoOffset))
586 reportError(std::move(E), Obj->getFileName());
587 if (XContents.empty())
588 return;
589
590 UnwindInfoOffset += RF.UnwindInfoOffset;
591 if (UnwindInfoOffset > XContents.size())
592 return;
593
594 auto *UI = reinterpret_cast<const Win64EH::UnwindInfo *>(XContents.data() +
595 UnwindInfoOffset);
596 printWin64EHUnwindInfo(UI);
597}
598
599void objdump::printCOFFUnwindInfo(const COFFObjectFile *Obj) {
600 if (Obj->getMachine() != COFF::IMAGE_FILE_MACHINE_AMD64) {
1
Assuming the condition is false
→
2
←
Taking false branch
→
601 WithColor::error(errs(), "llvm-objdump")
602 << "unsupported image machine type "
603 "(currently only AMD64 is supported).\n";
604 return;
605 }
606
607 std::vector<RelocationRef> Rels;
608 const RuntimeFunction *RFStart;
609 int NumRFs;
610 if (!getPDataSection(Obj, Rels, RFStart, NumRFs))
3
←
Taking false branch
→
611 return;
612 ArrayRef<RuntimeFunction> RFs(RFStart, NumRFs);
613
614 bool IsExecutable = Rels.empty();
615 if (IsExecutable) {
4
←
Assuming 'IsExecutable' is false
→
5
←
Taking false branch
→
616 for (const RuntimeFunction &RF : RFs)
617 printRuntimeFunction(Obj, RF);
618 return;
619 }
620
621 for (const RuntimeFunction &RF : RFs) {
6
←
Assuming '__begin1' is not equal to '__end1'
→
622 uint64_t SectionOffset =
623 std::distance(RFs.begin(), &RF) * sizeof(RuntimeFunction);
624 printRuntimeFunctionRels(Obj, RF, SectionOffset, Rels);
7
←
Calling 'printRuntimeFunctionRels'
→
625 }
626}
627
628void objdump::printCOFFFileHeader(const object::ObjectFile *Obj) {
629 const COFFObjectFile *file = dyn_cast<const COFFObjectFile>(Obj);
630 printTLSDirectory(file);
631 printLoadConfiguration(file);
632 printImportTables(file);
633 printExportTable(file);
634}
635
636void objdump::printCOFFSymbolTable(const object::COFFImportFile *i) {
637 unsigned Index = 0;
638 bool IsCode = i->getCOFFImportHeader()->getType() == COFF::IMPORT_CODE;
639
640 for (const object::BasicSymbolRef &Sym : i->symbols()) {
641 std::string Name;
642 raw_string_ostream NS(Name);
643
644 cantFail(Sym.printName(NS));
645 NS.flush();
646
647 outs() << "[" << format("%2d", Index) << "]"
648 << "(sec " << format("%2d", 0) << ")"
649 << "(fl 0x00)" // Flag bits, which COFF doesn't have.
650 << "(ty " << format("%3x", (IsCode && Index) ? 32 : 0) << ")"
651 << "(scl " << format("%3x", 0) << ") "
652 << "(nx " << 0 << ") "
653 << "0x" << format("%08x", 0) << " " << Name << '\n';
654
655 ++Index;
656 }
657}
658
659void objdump::printCOFFSymbolTable(const COFFObjectFile *coff) {
660 for (unsigned SI = 0, SE = coff->getNumberOfSymbols(); SI != SE; ++SI) {
661 Expected<COFFSymbolRef> Symbol = coff->getSymbol(SI);
662 if (!Symbol)
663 reportError(Symbol.takeError(), coff->getFileName());
664
665 Expected<StringRef> NameOrErr = coff->getSymbolName(*Symbol);
666 if (!NameOrErr)
667 reportError(NameOrErr.takeError(), coff->getFileName());
668 StringRef Name = *NameOrErr;
669
670 outs() << "[" << format("%2d", SI) << "]"
671 << "(sec " << format("%2d", int(Symbol->getSectionNumber())) << ")"
672 << "(fl 0x00)" // Flag bits, which COFF doesn't have.
673 << "(ty " << format("%3x", unsigned(Symbol->getType())) << ")"
674 << "(scl " << format("%3x", unsigned(Symbol->getStorageClass()))
675 << ") "
676 << "(nx " << unsigned(Symbol->getNumberOfAuxSymbols()) << ") "
677 << "0x" << format("%08x", unsigned(Symbol->getValue())) << " "
678 << Name;
679 if (Demangle && Name.startswith("?")) {
680 int Status = -1;
681 char *DemangledSymbol =
682 microsoftDemangle(Name.data(), nullptr, nullptr, nullptr, &Status);
683
684 if (Status == 0 && DemangledSymbol) {
685 outs() << " (" << StringRef(DemangledSymbol) << ")";
686 std::free(DemangledSymbol);
687 } else {
688 outs() << " (invalid mangled name)";
689 }
690 }
691 outs() << "\n";
692
693 for (unsigned AI = 0, AE = Symbol->getNumberOfAuxSymbols(); AI < AE; ++AI, ++SI) {
694 if (Symbol->isSectionDefinition()) {
695 const coff_aux_section_definition *asd;
696 if (Error E =
697 coff->getAuxSymbol<coff_aux_section_definition>(SI + 1, asd))
698 reportError(std::move(E), coff->getFileName());
699
700 int32_t AuxNumber = asd->getNumber(Symbol->isBigObj());
701
702 outs() << "AUX "
703 << format("scnlen 0x%x nreloc %d nlnno %d checksum 0x%x "
704 , unsigned(asd->Length)
705 , unsigned(asd->NumberOfRelocations)
706 , unsigned(asd->NumberOfLinenumbers)
707 , unsigned(asd->CheckSum))
708 << format("assoc %d comdat %d\n"
709 , unsigned(AuxNumber)
710 , unsigned(asd->Selection));
711 } else if (Symbol->isFileRecord()) {
712 const char *FileName;
713 if (Error E = coff->getAuxSymbol<char>(SI + 1, FileName))
714 reportError(std::move(E), coff->getFileName());
715
716 StringRef Name(FileName, Symbol->getNumberOfAuxSymbols() *
717 coff->getSymbolTableEntrySize());
718 outs() << "AUX " << Name.rtrim(StringRef("\0", 1)) << '\n';
719
720 SI = SI + Symbol->getNumberOfAuxSymbols();
721 break;
722 } else if (Symbol->isWeakExternal()) {
723 const coff_aux_weak_external *awe;
724 if (Error E = coff->getAuxSymbol<coff_aux_weak_external>(SI + 1, awe))
725 reportError(std::move(E), coff->getFileName());
726
727 outs() << "AUX " << format("indx %d srch %d\n",
728 static_cast<uint32_t>(awe->TagIndex),
729 static_cast<uint32_t>(awe->Characteristics));
730 } else {
731 outs() << "AUX Unknown\n";
732 }
733 }
734 }
735}
←

/usr/src/gnu/usr.bin/clang/llvm-objdump/../../../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);
19
←
Assuming the condition is true
→
237 return getPtr() != nullptr;
10
←
Returning zero, which participates in a condition later
→
20
←
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