Bug Summary

File:include/llvm/Support/Error.h
Warning:line 201, column 5
Potential leak of memory pointed to by 'Payload._M_t._M_head_impl'

Annotated Source Code

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clang -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name Driver.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 -mrelocation-model pic -pic-level 2 -mthread-model posix -fmath-errno -masm-verbose -mconstructor-aliases -munwind-tables -fuse-init-array -target-cpu x86-64 -dwarf-column-info -debugger-tuning=gdb -momit-leaf-frame-pointer -ffunction-sections -fdata-sections -resource-dir /usr/lib/llvm-8/lib/clang/8.0.0 -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-8~svn345461/build-llvm/tools/lld/wasm -I /build/llvm-toolchain-snapshot-8~svn345461/tools/lld/wasm -I /build/llvm-toolchain-snapshot-8~svn345461/tools/lld/include -I /build/llvm-toolchain-snapshot-8~svn345461/build-llvm/tools/lld/include -I /build/llvm-toolchain-snapshot-8~svn345461/build-llvm/include -I /build/llvm-toolchain-snapshot-8~svn345461/include -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0/backward -internal-isystem /usr/include/clang/8.0.0/include/ -internal-isystem /usr/local/include -internal-isystem /usr/lib/llvm-8/lib/clang/8.0.0/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-comment -std=c++11 -fdeprecated-macro -fdebug-compilation-dir /build/llvm-toolchain-snapshot-8~svn345461/build-llvm/tools/lld/wasm -ferror-limit 19 -fmessage-length 0 -fvisibility-inlines-hidden -fobjc-runtime=gcc -fdiagnostics-show-option -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -o /tmp/scan-build-2018-10-27-211344-32123-1 -x c++ /build/llvm-toolchain-snapshot-8~svn345461/tools/lld/wasm/Driver.cpp -faddrsig

/build/llvm-toolchain-snapshot-8~svn345461/tools/lld/wasm/Driver.cpp

→
1//===- Driver.cpp ---------------------------------------------------------===//
2//
3// The LLVM Linker
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9
10#include "lld/Common/Driver.h"
11#include "Config.h"
12#include "InputChunks.h"
13#include "InputGlobal.h"
14#include "MarkLive.h"
15#include "SymbolTable.h"
16#include "Writer.h"
17#include "lld/Common/Args.h"
18#include "lld/Common/ErrorHandler.h"
19#include "lld/Common/Memory.h"
20#include "lld/Common/Strings.h"
21#include "lld/Common/Threads.h"
22#include "lld/Common/Version.h"
23#include "llvm/ADT/Twine.h"
24#include "llvm/Object/Wasm.h"
25#include "llvm/Option/ArgList.h"
26#include "llvm/Support/CommandLine.h"
27#include "llvm/Support/Path.h"
28#include "llvm/Support/Process.h"
29#include "llvm/Support/TargetSelect.h"
30
31#define DEBUG_TYPE"lld" "lld"
32
33using namespace llvm;
34using namespace llvm::sys;
35using namespace llvm::wasm;
36
37using namespace lld;
38using namespace lld::wasm;
39
40Configuration *lld::wasm::Config;
41
42namespace {
43
44// Create enum with OPT_xxx values for each option in Options.td
45enum {
46 OPT_INVALID = 0,
47#define OPTION(_1, _2, ID, _4, _5, _6, _7, _8, _9, _10, _11, _12) OPT_##ID,
48#include "Options.inc"
49#undef OPTION
50};
51
52// This function is called on startup. We need this for LTO since
53// LTO calls LLVM functions to compile bitcode files to native code.
54// Technically this can be delayed until we read bitcode files, but
55// we don't bother to do lazily because the initialization is fast.
56static void initLLVM() {
57 InitializeAllTargets();
58 InitializeAllTargetMCs();
59 InitializeAllAsmPrinters();
60 InitializeAllAsmParsers();
61}
62
63class LinkerDriver {
64public:
65 void link(ArrayRef<const char *> ArgsArr);
66
67private:
68 void createFiles(opt::InputArgList &Args);
69 void addFile(StringRef Path);
70 void addLibrary(StringRef Name);
71
72 // True if we are in --whole-archive and --no-whole-archive.
73 bool InWholeArchive = false;
74
75 std::vector<InputFile *> Files;
76};
77} // anonymous namespace
78
79bool lld::wasm::link(ArrayRef<const char *> Args, bool CanExitEarly,
80 raw_ostream &Error) {
81 errorHandler().LogName = args::getFilenameWithoutExe(Args[0]);
82 errorHandler().ErrorOS = &Error;
83 errorHandler().ColorDiagnostics = Error.has_colors();
84 errorHandler().ErrorLimitExceededMsg =
85 "too many errors emitted, stopping now (use "
86 "-error-limit=0 to see all errors)";
87
88 Config = make<Configuration>();
89 Symtab = make<SymbolTable>();
90
91 initLLVM();
92 LinkerDriver().link(Args);
1
Calling 'LinkerDriver::link'
→
93
94 // Exit immediately if we don't need to return to the caller.
95 // This saves time because the overhead of calling destructors
96 // for all globally-allocated objects is not negligible.
97 if (CanExitEarly)
98 exitLld(errorCount() ? 1 : 0);
99
100 freeArena();
101 return !errorCount();
102}
103
104// Create prefix string literals used in Options.td
105#define PREFIX(NAME, VALUE) const char *const NAME[] = VALUE;
106#include "Options.inc"
107#undef PREFIX
108
109// Create table mapping all options defined in Options.td
110static const opt::OptTable::Info OptInfo[] = {
111#define OPTION(X1, X2, ID, KIND, GROUP, ALIAS, X7, X8, X9, X10, X11, X12) \
112 {X1, X2, X10, X11, OPT_##ID, opt::Option::KIND##Class, \
113 X9, X8, OPT_##GROUP, OPT_##ALIAS, X7, X12},
114#include "Options.inc"
115#undef OPTION
116};
117
118namespace {
119class WasmOptTable : public llvm::opt::OptTable {
120public:
121 WasmOptTable() : OptTable(OptInfo) {}
122 opt::InputArgList parse(ArrayRef<const char *> Argv);
123};
124} // namespace
125
126// Set color diagnostics according to -color-diagnostics={auto,always,never}
127// or -no-color-diagnostics flags.
128static void handleColorDiagnostics(opt::InputArgList &Args) {
129 auto *Arg = Args.getLastArg(OPT_color_diagnostics, OPT_color_diagnostics_eq,
130 OPT_no_color_diagnostics);
131 if (!Arg)
132 return;
133 if (Arg->getOption().getID() == OPT_color_diagnostics) {
134 errorHandler().ColorDiagnostics = true;
135 } else if (Arg->getOption().getID() == OPT_no_color_diagnostics) {
136 errorHandler().ColorDiagnostics = false;
137 } else {
138 StringRef S = Arg->getValue();
139 if (S == "always")
140 errorHandler().ColorDiagnostics = true;
141 else if (S == "never")
142 errorHandler().ColorDiagnostics = false;
143 else if (S != "auto")
144 error("unknown option: --color-diagnostics=" + S);
145 }
146}
147
148// Find a file by concatenating given paths.
149static Optional<std::string> findFile(StringRef Path1, const Twine &Path2) {
150 SmallString<128> S;
151 path::append(S, Path1, Path2);
152 if (fs::exists(S))
153 return S.str().str();
154 return None;
155}
156
157opt::InputArgList WasmOptTable::parse(ArrayRef<const char *> Argv) {
158 SmallVector<const char *, 256> Vec(Argv.data(), Argv.data() + Argv.size());
159
160 unsigned MissingIndex;
161 unsigned MissingCount;
162
163 // Expand response files (arguments in the form of @<filename>)
164 cl::ExpandResponseFiles(Saver, cl::TokenizeGNUCommandLine, Vec);
165
166 opt::InputArgList Args = this->ParseArgs(Vec, MissingIndex, MissingCount);
167
168 handleColorDiagnostics(Args);
169 for (auto *Arg : Args.filtered(OPT_UNKNOWN))
170 error("unknown argument: " + Arg->getSpelling());
171 return Args;
172}
173
174// Currently we allow a ".imports" to live alongside a library. This can
175// be used to specify a list of symbols which can be undefined at link
176// time (imported from the environment. For example libc.a include an
177// import file that lists the syscall functions it relies on at runtime.
178// In the long run this information would be better stored as a symbol
179// attribute/flag in the object file itself.
180// See: https://github.com/WebAssembly/tool-conventions/issues/35
181static void readImportFile(StringRef Filename) {
182 if (Optional<MemoryBufferRef> Buf = readFile(Filename))
183 for (StringRef Sym : args::getLines(*Buf))
184 Config->AllowUndefinedSymbols.insert(Sym);
185}
186
187// Returns slices of MB by parsing MB as an archive file.
188// Each slice consists of a member file in the archive.
189std::vector<MemoryBufferRef> static getArchiveMembers(MemoryBufferRef MB) {
190 std::unique_ptr<Archive> File =
191 CHECK(Archive::create(MB),check2((Archive::create(MB)), [&] { return toString(MB.getBufferIdentifier
() + ": failed to parse archive"); })
192 MB.getBufferIdentifier() + ": failed to parse archive")check2((Archive::create(MB)), [&] { return toString(MB.getBufferIdentifier
() + ": failed to parse archive"); });
193
194 std::vector<MemoryBufferRef> V;
195 Error Err = Error::success();
196 for (const ErrorOr<Archive::Child> &COrErr : File->children(Err)) {
197 Archive::Child C =
198 CHECK(COrErr, MB.getBufferIdentifier() +check2((COrErr), [&] { return toString(MB.getBufferIdentifier
() + ": could not get the child of the archive"); })
199 ": could not get the child of the archive")check2((COrErr), [&] { return toString(MB.getBufferIdentifier
() + ": could not get the child of the archive"); });
200 MemoryBufferRef MBRef =
201 CHECK(C.getMemoryBufferRef(),check2((C.getMemoryBufferRef()), [&] { return toString(MB
.getBufferIdentifier() + ": could not get the buffer for a child of the archive"
); })
202 MB.getBufferIdentifier() +check2((C.getMemoryBufferRef()), [&] { return toString(MB
.getBufferIdentifier() + ": could not get the buffer for a child of the archive"
); })
203 ": could not get the buffer for a child of the archive")check2((C.getMemoryBufferRef()), [&] { return toString(MB
.getBufferIdentifier() + ": could not get the buffer for a child of the archive"
); });
204 V.push_back(MBRef);
205 }
206 if (Err)
207 fatal(MB.getBufferIdentifier() +
208 ": Archive::children failed: " + toString(std::move(Err)));
209
210 // Take ownership of memory buffers created for members of thin archives.
211 for (std::unique_ptr<MemoryBuffer> &MB : File->takeThinBuffers())
212 make<std::unique_ptr<MemoryBuffer>>(std::move(MB));
213
214 return V;
215}
216
217void LinkerDriver::addFile(StringRef Path) {
218 Optional<MemoryBufferRef> Buffer = readFile(Path);
219 if (!Buffer.hasValue())
220 return;
221 MemoryBufferRef MBRef = *Buffer;
222
223 switch (identify_magic(MBRef.getBuffer())) {
224 case file_magic::archive: {
225 // Handle -whole-archive.
226 if (InWholeArchive) {
227 for (MemoryBufferRef &M : getArchiveMembers(MBRef))
228 Files.push_back(createObjectFile(M));
229 return;
230 }
231
232 SmallString<128> ImportFile = Path;
233 path::replace_extension(ImportFile, ".imports");
234 if (fs::exists(ImportFile))
235 readImportFile(ImportFile.str());
236
237 Files.push_back(make<ArchiveFile>(MBRef));
238 return;
239 }
240 case file_magic::bitcode:
241 case file_magic::wasm_object:
242 Files.push_back(createObjectFile(MBRef));
243 break;
244 default:
245 error("unknown file type: " + MBRef.getBufferIdentifier());
246 }
247}
248
249// Add a given library by searching it from input search paths.
250void LinkerDriver::addLibrary(StringRef Name) {
251 for (StringRef Dir : Config->SearchPaths) {
252 if (Optional<std::string> S = findFile(Dir, "lib" + Name + ".a")) {
253 addFile(*S);
254 return;
255 }
256 }
257
258 error("unable to find library -l" + Name);
259}
260
261void LinkerDriver::createFiles(opt::InputArgList &Args) {
262 for (auto *Arg : Args) {
263 switch (Arg->getOption().getUnaliasedOption().getID()) {
264 case OPT_l:
265 addLibrary(Arg->getValue());
266 break;
267 case OPT_INPUT:
268 addFile(Arg->getValue());
269 break;
270 case OPT_whole_archive:
271 InWholeArchive = true;
272 break;
273 case OPT_no_whole_archive:
274 InWholeArchive = false;
275 break;
276 }
277 }
278}
279
280static StringRef getEntry(opt::InputArgList &Args, StringRef Default) {
281 auto *Arg = Args.getLastArg(OPT_entry, OPT_no_entry);
282 if (!Arg)
283 return Default;
284 if (Arg->getOption().getID() == OPT_no_entry)
285 return "";
286 return Arg->getValue();
287}
288
289static const uint8_t UnreachableFn[] = {
290 0x03 /* ULEB length */, 0x00 /* ULEB num locals */,
291 0x00 /* opcode unreachable */, 0x0b /* opcode end */
292};
293
294// For weak undefined functions, there may be "call" instructions that reference
295// the symbol. In this case, we need to synthesise a dummy/stub function that
296// will abort at runtime, so that relocations can still provided an operand to
297// the call instruction that passes Wasm validation.
298static void handleWeakUndefines() {
299 for (Symbol *Sym : Symtab->getSymbols()) {
300 if (!Sym->isUndefined() || !Sym->isWeak())
301 continue;
302 auto *FuncSym = dyn_cast<FunctionSymbol>(Sym);
303 if (!FuncSym)
304 continue;
305
306 // It is possible for undefined functions not to have a signature (eg. if
307 // added via "--undefined"), but weak undefined ones do have a signature.
308 assert(FuncSym->FunctionType)((FuncSym->FunctionType) ? static_cast<void> (0) : __assert_fail
("FuncSym->FunctionType", "/build/llvm-toolchain-snapshot-8~svn345461/tools/lld/wasm/Driver.cpp"
, 308, __PRETTY_FUNCTION__));
309 const WasmSignature &Sig = *FuncSym->FunctionType;
310
311 // Add a synthetic dummy for weak undefined functions. These dummies will
312 // be GC'd if not used as the target of any "call" instructions.
313 Optional<std::string> SymName = demangleItanium(Sym->getName());
314 StringRef DebugName =
315 Saver.save("undefined function " +
316 (SymName ? StringRef(*SymName) : Sym->getName()));
317 SyntheticFunction *Func =
318 make<SyntheticFunction>(Sig, Sym->getName(), DebugName);
319 Func->setBody(UnreachableFn);
320 // Ensure it compares equal to the null pointer, and so that table relocs
321 // don't pull in the stub body (only call-operand relocs should do that).
322 Func->setTableIndex(0);
323 Symtab->SyntheticFunctions.emplace_back(Func);
324 // Hide our dummy to prevent export.
325 uint32_t Flags = WASM_SYMBOL_VISIBILITY_HIDDEN;
326 replaceSymbol<DefinedFunction>(Sym, Sym->getName(), Flags, nullptr, Func);
327 }
328}
329
330// Force Sym to be entered in the output. Used for -u or equivalent.
331static Symbol *handleUndefined(StringRef Name) {
332 Symbol *Sym = Symtab->find(Name);
333 if (!Sym)
334 return nullptr;
335
336 // Since symbol S may not be used inside the program, LTO may
337 // eliminate it. Mark the symbol as "used" to prevent it.
338 Sym->IsUsedInRegularObj = true;
339
340 if (auto *LazySym = dyn_cast<LazySymbol>(Sym))
341 LazySym->fetch();
342
343 return Sym;
344}
345
346void LinkerDriver::link(ArrayRef<const char *> ArgsArr) {
347 WasmOptTable Parser;
348 opt::InputArgList Args = Parser.parse(ArgsArr.slice(1));
349
350 // Handle --help
351 if (Args.hasArg(OPT_help)) {
2
←
Assuming the condition is false
→
3
←
Taking false branch
→
352 Parser.PrintHelp(outs(),
353 (std::string(ArgsArr[0]) + " [options] file...").c_str(),
354 "LLVM Linker", false);
355 return;
356 }
357
358 // Handle --version
359 if (Args.hasArg(OPT_version) || Args.hasArg(OPT_v)) {
4
←
Assuming the condition is false
→
5
←
Assuming the condition is false
→
6
←
Taking false branch
→
360 outs() << getLLDVersion() << "\n";
361 return;
362 }
363
364 // Parse and evaluate -mllvm options.
365 std::vector<const char *> V;
366 V.push_back("wasm-ld (LLVM option parsing)");
367 for (auto *Arg : Args.filtered(OPT_mllvm))
368 V.push_back(Arg->getValue());
369 cl::ParseCommandLineOptions(V.size(), V.data());
370
371 errorHandler().ErrorLimit = args::getInteger(Args, OPT_error_limit, 20);
372
373 Config->AllowUndefined = Args.hasArg(OPT_allow_undefined);
374 Config->Demangle = Args.hasFlag(OPT_demangle, OPT_no_demangle, true);
375 Config->DisableVerify = Args.hasArg(OPT_disable_verify);
376 Config->Entry = getEntry(Args, Args.hasArg(OPT_relocatable) ? "" : "_start");
7
←
Assuming the condition is false
→
8
←
'?' condition is false
→
377 Config->ExportAll = Args.hasArg(OPT_export_all);
378 Config->ExportDynamic = Args.hasFlag(OPT_export_dynamic,
379 OPT_no_export_dynamic, false);
380 Config->ExportTable = Args.hasArg(OPT_export_table);
381 errorHandler().FatalWarnings =
382 Args.hasFlag(OPT_fatal_warnings, OPT_no_fatal_warnings, false);
383 Config->ImportMemory = Args.hasArg(OPT_import_memory);
384 Config->ImportTable = Args.hasArg(OPT_import_table);
385 Config->LTOO = args::getInteger(Args, OPT_lto_O, 2);
386 Config->LTOPartitions = args::getInteger(Args, OPT_lto_partitions, 1);
387 Config->Optimize = args::getInteger(Args, OPT_O, 0);
388 Config->OutputFile = Args.getLastArgValue(OPT_o);
389 Config->Relocatable = Args.hasArg(OPT_relocatable);
390 Config->GcSections =
391 Args.hasFlag(OPT_gc_sections, OPT_no_gc_sections, !Config->Relocatable);
9
←
Assuming the condition is false
→
392 Config->MergeDataSegments =
393 Args.hasFlag(OPT_merge_data_segments, OPT_no_merge_data_segments,
394 !Config->Relocatable);
10
←
Assuming the condition is false
→
395 Config->PrintGcSections =
396 Args.hasFlag(OPT_print_gc_sections, OPT_no_print_gc_sections, false);
397 Config->SaveTemps = Args.hasArg(OPT_save_temps);
398 Config->SearchPaths = args::getStrings(Args, OPT_L);
399 Config->StripAll = Args.hasArg(OPT_strip_all);
400 Config->StripDebug = Args.hasArg(OPT_strip_debug);
401 Config->CompressRelocations = Args.hasArg(OPT_compress_relocations);
402 Config->StackFirst = Args.hasArg(OPT_stack_first);
403 Config->ThinLTOCacheDir = Args.getLastArgValue(OPT_thinlto_cache_dir);
404 Config->ThinLTOCachePolicy = CHECK(check2((parseCachePruningPolicy(Args.getLastArgValue(OPT_thinlto_cache_policy
))), [&] { return toString("--thinlto-cache-policy: invalid cache policy"
); })
11
←
Within the expansion of the macro 'CHECK':
→
a
Calling 'check2<llvm::CachePruningPolicy>'
405 parseCachePruningPolicy(Args.getLastArgValue(OPT_thinlto_cache_policy)),check2((parseCachePruningPolicy(Args.getLastArgValue(OPT_thinlto_cache_policy
))), [&] { return toString("--thinlto-cache-policy: invalid cache policy"
); })
406 "--thinlto-cache-policy: invalid cache policy")check2((parseCachePruningPolicy(Args.getLastArgValue(OPT_thinlto_cache_policy
))), [&] { return toString("--thinlto-cache-policy: invalid cache policy"
); });
407 Config->ThinLTOJobs = args::getInteger(Args, OPT_thinlto_jobs, -1u);
408 errorHandler().Verbose = Args.hasArg(OPT_verbose);
409 ThreadsEnabled = Args.hasFlag(OPT_threads, OPT_no_threads, true);
410
411 Config->InitialMemory = args::getInteger(Args, OPT_initial_memory, 0);
412 Config->GlobalBase = args::getInteger(Args, OPT_global_base, 1024);
413 Config->MaxMemory = args::getInteger(Args, OPT_max_memory, 0);
414 Config->ZStackSize =
415 args::getZOptionValue(Args, OPT_z, "stack-size", WasmPageSize);
416
417 if (!Config->StripDebug && !Config->StripAll && Config->CompressRelocations)
418 error("--compress-relocations is incompatible with output debug"
419 " information. Please pass --strip-debug or --strip-all");
420
421 if (Config->LTOO > 3)
422 error("invalid optimization level for LTO: " + Twine(Config->LTOO));
423 if (Config->LTOPartitions == 0)
424 error("--lto-partitions: number of threads must be > 0");
425 if (Config->ThinLTOJobs == 0)
426 error("--thinlto-jobs: number of threads must be > 0");
427
428 if (auto *Arg = Args.getLastArg(OPT_allow_undefined_file))
429 readImportFile(Arg->getValue());
430
431 if (!Args.hasArg(OPT_INPUT)) {
432 error("no input files");
433 return;
434 }
435
436 if (Config->OutputFile.empty())
437 error("no output file specified");
438
439 if (Config->ImportTable && Config->ExportTable)
440 error("--import-table and --export-table may not be used together");
441
442 if (Config->Relocatable) {
443 if (!Config->Entry.empty())
444 error("entry point specified for relocatable output file");
445 if (Config->GcSections)
446 error("-r and --gc-sections may not be used together");
447 if (Config->CompressRelocations)
448 error("-r -and --compress-relocations may not be used together");
449 if (Args.hasArg(OPT_undefined))
450 error("-r -and --undefined may not be used together");
451 }
452
453 Symbol *EntrySym = nullptr;
454 if (!Config->Relocatable) {
455 llvm::wasm::WasmGlobal Global;
456 Global.Type = {WASM_TYPE_I32, true};
457 Global.InitExpr.Value.Int32 = 0;
458 Global.InitExpr.Opcode = WASM_OPCODE_I32_CONST;
459 Global.SymbolName = "__stack_pointer";
460 InputGlobal *StackPointer = make<InputGlobal>(Global, nullptr);
461 StackPointer->Live = true;
462
463 static WasmSignature NullSignature = {{}, {}};
464
465 // Add synthetic symbols before any others
466 WasmSym::CallCtors = Symtab->addSyntheticFunction(
467 "__wasm_call_ctors", WASM_SYMBOL_VISIBILITY_HIDDEN,
468 make<SyntheticFunction>(NullSignature, "__wasm_call_ctors"));
469 // TODO(sbc): Remove WASM_SYMBOL_VISIBILITY_HIDDEN when the mutable global
470 // spec proposal is implemented in all major browsers.
471 // See: https://github.com/WebAssembly/mutable-global
472 WasmSym::StackPointer = Symtab->addSyntheticGlobal(
473 "__stack_pointer", WASM_SYMBOL_VISIBILITY_HIDDEN, StackPointer);
474 WasmSym::HeapBase = Symtab->addSyntheticDataSymbol("__heap_base", 0);
475 WasmSym::DsoHandle = Symtab->addSyntheticDataSymbol(
476 "__dso_handle", WASM_SYMBOL_VISIBILITY_HIDDEN);
477 WasmSym::DataEnd = Symtab->addSyntheticDataSymbol("__data_end", 0);
478
479 // These two synthetic symbols exist purely for the embedder so we always
480 // want to export them.
481 WasmSym::HeapBase->ForceExport = true;
482 WasmSym::DataEnd->ForceExport = true;
483 }
484
485 createFiles(Args);
486 if (errorCount())
487 return;
488
489 // Add all files to the symbol table. This will add almost all
490 // symbols that we need to the symbol table.
491 for (InputFile *F : Files)
492 Symtab->addFile(F);
493 if (errorCount())
494 return;
495
496 // Handle the `--undefined <sym>` options.
497 for (auto *Arg : Args.filtered(OPT_undefined))
498 handleUndefined(Arg->getValue());
499
500 // Handle the `--export <sym>` options
501 // This works like --undefined but also exports the symbol if its found
502 for (auto *Arg : Args.filtered(OPT_export)) {
503 Symbol *Sym = handleUndefined(Arg->getValue());
504 if (Sym && Sym->isDefined())
505 Sym->ForceExport = true;
506 else if (!Config->AllowUndefined)
507 error(Twine("symbol exported via --export not found: ") +
508 Arg->getValue());
509 }
510
511 if (!Config->Relocatable) {
512 // Add synthetic dummies for weak undefined functions.
513 handleWeakUndefines();
514
515 if (!Config->Entry.empty()) {
516 EntrySym = handleUndefined(Config->Entry);
517 if (EntrySym && EntrySym->isDefined())
518 EntrySym->ForceExport = true;
519 else
520 error("entry symbol not defined (pass --no-entry to supress): " +
521 Config->Entry);
522 }
523
524 // Make sure we have resolved all symbols.
525 if (!Config->AllowUndefined)
526 Symtab->reportRemainingUndefines();
527 }
528
529 if (errorCount())
530 return;
531
532 // Do link-time optimization if given files are LLVM bitcode files.
533 // This compiles bitcode files into real object files.
534 Symtab->addCombinedLTOObject();
535 if (errorCount())
536 return;
537
538 if (EntrySym)
539 EntrySym->setHidden(false);
540
541 if (errorCount())
542 return;
543
544 // Do size optimizations: garbage collection
545 markLive();
546
547 // Write the result to the file.
548 writeResult();
549}
←

/build/llvm-toolchain-snapshot-8~svn345461/tools/lld/include/lld/Common/ErrorHandler.h

→
1//===- ErrorHandler.h -------------------------------------------*- C++ -*-===//
2//
3// The LLVM Linker
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// We designed lld's error handlers with the following goals in mind:
11//
12// - Errors can occur at any place where we handle user input, but we don't
13// want them to affect the normal execution path too much. Ideally,
14// handling errors should be as simple as reporting them and exit (but
15// without actually doing exit).
16//
17// In particular, the design to wrap all functions that could fail with
18// ErrorOr<T> is rejected because otherwise we would have to wrap a large
19// number of functions in lld with ErrorOr. With that approach, if some
20// function F can fail, not only F but all functions that transitively call
21// F have to be wrapped with ErrorOr. That seemed too much.
22//
23// - Finding only one error at a time is not sufficient. We want to find as
24// many errors as possible with one execution of the linker. That means the
25// linker needs to keep running after a first error and give up at some
26// checkpoint (beyond which it would find cascading, false errors caused by
27// the previous errors).
28//
29// - We want a simple interface to report errors. Unlike Clang, the data we
30// handle is compiled binary, so we don't need an error reporting mechanism
31// that's as sophisticated as the one that Clang has.
32//
33// The current lld's error handling mechanism is simple:
34//
35// - When you find an error, report it using error() and continue as far as
36// you can. An internal error counter is incremented by one every time you
37// call error().
38//
39// A common idiom to handle an error is calling error() and then returning
40// a reasonable default value. For example, if your function handles a
41// user-supplied alignment value, and if you find an invalid alignment
42// (e.g. 17 which is not 2^n), you may report it using error() and continue
43// as if it were alignment 1 (which is the simplest reasonable value).
44//
45// Note that you should not continue with an invalid value; that breaks the
46// internal consistency. You need to maintain all variables have some sane
47// value even after an error occurred. So, when you have to continue with
48// some value, always use a dummy value.
49//
50// - Find a reasonable checkpoint at where you want to stop the linker, and
51// add code to return from the function if errorCount() > 0. In most cases,
52// a checkpoint already exists, so you don't need to do anything for this.
53//
54// This interface satisfies all the goals that we mentioned above.
55//
56// You should never call fatal() except for reporting a corrupted input file.
57// fatal() immediately terminates the linker, so the function is not desirable
58// if you are using lld as a subroutine in other program, and with that you
59// can find only one error at a time.
60//
61// warn() doesn't do anything but printing out a given message.
62//
63// It is not recommended to use llvm::outs() or llvm::errs() directly in lld
64// because they are not thread-safe. The functions declared in this file are
65// thread-safe.
66//
67//===----------------------------------------------------------------------===//
68
69#ifndef LLD_COMMON_ERRORHANDLER_H
70#define LLD_COMMON_ERRORHANDLER_H
71
72#include "lld/Common/LLVM.h"
73
74#include "llvm/ADT/STLExtras.h"
75#include "llvm/Support/Error.h"
76#include "llvm/Support/FileOutputBuffer.h"
77
78namespace llvm {
79class DiagnosticInfo;
80}
81
82namespace lld {
83
84class ErrorHandler {
85public:
86 uint64_t ErrorCount = 0;
87 uint64_t ErrorLimit = 20;
88 StringRef ErrorLimitExceededMsg = "too many errors emitted, stopping now";
89 StringRef LogName = "lld";
90 llvm::raw_ostream *ErrorOS = &llvm::errs();
91 bool ColorDiagnostics = llvm::errs().has_colors();
92 bool ExitEarly = true;
93 bool FatalWarnings = false;
94 bool Verbose = false;
95
96 void error(const Twine &Msg);
97 LLVM_ATTRIBUTE_NORETURN__attribute__((noreturn)) void fatal(const Twine &Msg);
98 void log(const Twine &Msg);
99 void message(const Twine &Msg);
100 void warn(const Twine &Msg);
101
102 std::unique_ptr<llvm::FileOutputBuffer> OutputBuffer;
103
104private:
105 void print(StringRef S, raw_ostream::Colors C);
106};
107
108/// Returns the default error handler.
109ErrorHandler &errorHandler();
110
111inline void error(const Twine &Msg) { errorHandler().error(Msg); }
112inline LLVM_ATTRIBUTE_NORETURN__attribute__((noreturn)) void fatal(const Twine &Msg) {
113 errorHandler().fatal(Msg);
114}
115inline void log(const Twine &Msg) { errorHandler().log(Msg); }
116inline void message(const Twine &Msg) { errorHandler().message(Msg); }
117inline void warn(const Twine &Msg) { errorHandler().warn(Msg); }
118inline uint64_t errorCount() { return errorHandler().ErrorCount; }
119
120LLVM_ATTRIBUTE_NORETURN__attribute__((noreturn)) void exitLld(int Val);
121
122void diagnosticHandler(const llvm::DiagnosticInfo &DI);
123void checkError(Error E);
124
125// check functions are convenient functions to strip errors
126// from error-or-value objects.
127template <class T> T check(ErrorOr<T> E) {
128 if (auto EC = E.getError())
129 fatal(EC.message());
130 return std::move(*E);
131}
132
133template <class T> T check(Expected<T> E) {
134 if (!E)
135 fatal(llvm::toString(E.takeError()));
136 return std::move(*E);
137}
138
139template <class T>
140T check2(ErrorOr<T> E, llvm::function_ref<std::string()> Prefix) {
141 if (auto EC = E.getError())
142 fatal(Prefix() + ": " + EC.message());
143 return std::move(*E);
144}
145
146template <class T>
147T check2(Expected<T> E, llvm::function_ref<std::string()> Prefix) {
148 if (!E)
12
←
Taking true branch
→
149 fatal(Prefix() + ": " + toString(E.takeError()));
13
←
Calling 'toString'
→
150 return std::move(*E);
151}
152
153inline std::string toString(const Twine &S) { return S.str(); }
154
155// To evaluate the second argument lazily, we use C macro.
156#define CHECK(E, S)check2((E), [&] { return toString(S); }) check2((E), [&] { return toString(S); })
157
158} // namespace lld
159
160#endif
←

/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h

1//===- llvm/Support/Error.h - Recoverable error handling --------*- C++ -*-===//
2//
3// The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file defines an API used to report recoverable errors.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_SUPPORT_ERROR_H
15#define LLVM_SUPPORT_ERROR_H
16
17#include "llvm-c/Error.h"
18#include "llvm/ADT/STLExtras.h"
19#include "llvm/ADT/SmallVector.h"
20#include "llvm/ADT/StringExtras.h"
21#include "llvm/ADT/Twine.h"
22#include "llvm/Config/abi-breaking.h"
23#include "llvm/Support/AlignOf.h"
24#include "llvm/Support/Compiler.h"
25#include "llvm/Support/Debug.h"
26#include "llvm/Support/ErrorHandling.h"
27#include "llvm/Support/ErrorOr.h"
28#include "llvm/Support/Format.h"
29#include "llvm/Support/raw_ostream.h"
30#include <algorithm>
31#include <cassert>
32#include <cstdint>
33#include <cstdlib>
34#include <functional>
35#include <memory>
36#include <new>
37#include <string>
38#include <system_error>
39#include <type_traits>
40#include <utility>
41#include <vector>
42
43namespace llvm {
44
45class ErrorSuccess;
46
47/// Base class for error info classes. Do not extend this directly: Extend
48/// the ErrorInfo template subclass instead.
49class ErrorInfoBase {
50public:
51 virtual ~ErrorInfoBase() = default;
52
53 /// Print an error message to an output stream.
54 virtual void log(raw_ostream &OS) const = 0;
55
56 /// Return the error message as a string.
57 virtual std::string message() const {
58 std::string Msg;
59 raw_string_ostream OS(Msg);
60 log(OS);
61 return OS.str();
62 }
63
64 /// Convert this error to a std::error_code.
65 ///
66 /// This is a temporary crutch to enable interaction with code still
67 /// using std::error_code. It will be removed in the future.
68 virtual std::error_code convertToErrorCode() const = 0;
69
70 // Returns the class ID for this type.
71 static const void *classID() { return &ID; }
72
73 // Returns the class ID for the dynamic type of this ErrorInfoBase instance.
74 virtual const void *dynamicClassID() const = 0;
75
76 // Check whether this instance is a subclass of the class identified by
77 // ClassID.
78 virtual bool isA(const void *const ClassID) const {
79 return ClassID == classID();
80 }
81
82 // Check whether this instance is a subclass of ErrorInfoT.
83 template <typename ErrorInfoT> bool isA() const {
84 return isA(ErrorInfoT::classID());
85 }
86
87private:
88 virtual void anchor();
89
90 static char ID;
91};
92
93/// Lightweight error class with error context and mandatory checking.
94///
95/// Instances of this class wrap a ErrorInfoBase pointer. Failure states
96/// are represented by setting the pointer to a ErrorInfoBase subclass
97/// instance containing information describing the failure. Success is
98/// represented by a null pointer value.
99///
100/// Instances of Error also contains a 'Checked' flag, which must be set
101/// before the destructor is called, otherwise the destructor will trigger a
102/// runtime error. This enforces at runtime the requirement that all Error
103/// instances be checked or returned to the caller.
104///
105/// There are two ways to set the checked flag, depending on what state the
106/// Error instance is in. For Error instances indicating success, it
107/// is sufficient to invoke the boolean conversion operator. E.g.:
108///
109/// @code{.cpp}
110/// Error foo(<...>);
111///
112/// if (auto E = foo(<...>))
113/// return E; // <- Return E if it is in the error state.
114/// // We have verified that E was in the success state. It can now be safely
115/// // destroyed.
116/// @endcode
117///
118/// A success value *can not* be dropped. For example, just calling 'foo(<...>)'
119/// without testing the return value will raise a runtime error, even if foo
120/// returns success.
121///
122/// For Error instances representing failure, you must use either the
123/// handleErrors or handleAllErrors function with a typed handler. E.g.:
124///
125/// @code{.cpp}
126/// class MyErrorInfo : public ErrorInfo<MyErrorInfo> {
127/// // Custom error info.
128/// };
129///
130/// Error foo(<...>) { return make_error<MyErrorInfo>(...); }
131///
132/// auto E = foo(<...>); // <- foo returns failure with MyErrorInfo.
133/// auto NewE =
134/// handleErrors(E,
135/// [](const MyErrorInfo &M) {
136/// // Deal with the error.
137/// },
138/// [](std::unique_ptr<OtherError> M) -> Error {
139/// if (canHandle(*M)) {
140/// // handle error.
141/// return Error::success();
142/// }
143/// // Couldn't handle this error instance. Pass it up the stack.
144/// return Error(std::move(M));
145/// );
146/// // Note - we must check or return NewE in case any of the handlers
147/// // returned a new error.
148/// @endcode
149///
150/// The handleAllErrors function is identical to handleErrors, except
151/// that it has a void return type, and requires all errors to be handled and
152/// no new errors be returned. It prevents errors (assuming they can all be
153/// handled) from having to be bubbled all the way to the top-level.
154///
155/// *All* Error instances must be checked before destruction, even if
156/// they're moved-assigned or constructed from Success values that have already
157/// been checked. This enforces checking through all levels of the call stack.
158class LLVM_NODISCARD[[clang::warn_unused_result]] Error {
159 // Both ErrorList and FileError need to be able to yank ErrorInfoBase
160 // pointers out of this class to add to the error list.
161 friend class ErrorList;
162 friend class FileError;
163
164 // handleErrors needs to be able to set the Checked flag.
165 template <typename... HandlerTs>
166 friend Error handleErrors(Error E, HandlerTs &&... Handlers);
167
168 // Expected<T> needs to be able to steal the payload when constructed from an
169 // error.
170 template <typename T> friend class Expected;
171
172 // wrap needs to be able to steal the payload.
173 friend LLVMErrorRef wrap(Error);
174
175protected:
176 /// Create a success value. Prefer using 'Error::success()' for readability
177 Error() {
178 setPtr(nullptr);
179 setChecked(false);
180 }
181
182public:
183 /// Create a success value.
184 static ErrorSuccess success();
185
186 // Errors are not copy-constructable.
187 Error(const Error &Other) = delete;
188
189 /// Move-construct an error value. The newly constructed error is considered
190 /// unchecked, even if the source error had been checked. The original error
191 /// becomes a checked Success value, regardless of its original state.
192 Error(Error &&Other) {
193 setChecked(true);
194 *this = std::move(Other);
195 }
196
197 /// Create an error value. Prefer using the 'make_error' function, but
198 /// this constructor can be useful when "re-throwing" errors from handlers.
199 Error(std::unique_ptr<ErrorInfoBase> Payload) {
200 setPtr(Payload.release());
201 setChecked(false);
28
←
Potential leak of memory pointed to by 'Payload._M_t._M_head_impl'
202 }
203
204 // Errors are not copy-assignable.
205 Error &operator=(const Error &Other) = delete;
206
207 /// Move-assign an error value. The current error must represent success, you
208 /// you cannot overwrite an unhandled error. The current error is then
209 /// considered unchecked. The source error becomes a checked success value,
210 /// regardless of its original state.
211 Error &operator=(Error &&Other) {
212 // Don't allow overwriting of unchecked values.
213 assertIsChecked();
214 setPtr(Other.getPtr());
215
216 // This Error is unchecked, even if the source error was checked.
217 setChecked(false);
218
219 // Null out Other's payload and set its checked bit.
220 Other.setPtr(nullptr);
221 Other.setChecked(true);
222
223 return *this;
224 }
225
226 /// Destroy a Error. Fails with a call to abort() if the error is
227 /// unchecked.
228 ~Error() {
229 assertIsChecked();
230 delete getPtr();
231 }
232
233 /// Bool conversion. Returns true if this Error is in a failure state,
234 /// and false if it is in an accept state. If the error is in a Success state
235 /// it will be considered checked.
236 explicit operator bool() {
237 setChecked(getPtr() == nullptr);
238 return getPtr() != nullptr;
239 }
240
241 /// Check whether one error is a subclass of another.
242 template <typename ErrT> bool isA() const {
243 return getPtr() && getPtr()->isA(ErrT::classID());
244 }
245
246 /// Returns the dynamic class id of this error, or null if this is a success
247 /// value.
248 const void* dynamicClassID() const {
249 if (!getPtr())
250 return nullptr;
251 return getPtr()->dynamicClassID();
252 }
253
254private:
255#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
256 // assertIsChecked() happens very frequently, but under normal circumstances
257 // is supposed to be a no-op. So we want it to be inlined, but having a bunch
258 // of debug prints can cause the function to be too large for inlining. So
259 // it's important that we define this function out of line so that it can't be
260 // inlined.
261 LLVM_ATTRIBUTE_NORETURN__attribute__((noreturn))
262 void fatalUncheckedError() const;
263#endif
264
265 void assertIsChecked() {
266#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
267 if (LLVM_UNLIKELY(!getChecked() || getPtr())__builtin_expect((bool)(!getChecked() || getPtr()), false))
268 fatalUncheckedError();
269#endif
270 }
271
272 ErrorInfoBase *getPtr() const {
273 return reinterpret_cast<ErrorInfoBase*>(
274 reinterpret_cast<uintptr_t>(Payload) &
275 ~static_cast<uintptr_t>(0x1));
276 }
277
278 void setPtr(ErrorInfoBase *EI) {
279#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
280 Payload = reinterpret_cast<ErrorInfoBase*>(
281 (reinterpret_cast<uintptr_t>(EI) &
282 ~static_cast<uintptr_t>(0x1)) |
283 (reinterpret_cast<uintptr_t>(Payload) & 0x1));
284#else
285 Payload = EI;
286#endif
287 }
288
289 bool getChecked() const {
290#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
291 return (reinterpret_cast<uintptr_t>(Payload) & 0x1) == 0;
292#else
293 return true;
294#endif
295 }
296
297 void setChecked(bool V) {
298 Payload = reinterpret_cast<ErrorInfoBase*>(
299 (reinterpret_cast<uintptr_t>(Payload) &
300 ~static_cast<uintptr_t>(0x1)) |
301 (V ? 0 : 1));
302 }
303
304 std::unique_ptr<ErrorInfoBase> takePayload() {
305 std::unique_ptr<ErrorInfoBase> Tmp(getPtr());
306 setPtr(nullptr);
307 setChecked(true);
308 return Tmp;
309 }
310
311 friend raw_ostream &operator<<(raw_ostream &OS, const Error &E) {
312 if (auto P = E.getPtr())
313 P->log(OS);
314 else
315 OS << "success";
316 return OS;
317 }
318
319 ErrorInfoBase *Payload = nullptr;
320};
321
322/// Subclass of Error for the sole purpose of identifying the success path in
323/// the type system. This allows to catch invalid conversion to Expected<T> at
324/// compile time.
325class ErrorSuccess final : public Error {};
326
327inline ErrorSuccess Error::success() { return ErrorSuccess(); }
328
329/// Make a Error instance representing failure using the given error info
330/// type.
331template <typename ErrT, typename... ArgTs> Error make_error(ArgTs &&... Args) {
332 return Error(llvm::make_unique<ErrT>(std::forward<ArgTs>(Args)...));
333}
334
335/// Base class for user error types. Users should declare their error types
336/// like:
337///
338/// class MyError : public ErrorInfo<MyError> {
339/// ....
340/// };
341///
342/// This class provides an implementation of the ErrorInfoBase::kind
343/// method, which is used by the Error RTTI system.
344template <typename ThisErrT, typename ParentErrT = ErrorInfoBase>
345class ErrorInfo : public ParentErrT {
346public:
347 using ParentErrT::ParentErrT; // inherit constructors
348
349 static const void *classID() { return &ThisErrT::ID; }
350
351 const void *dynamicClassID() const override { return &ThisErrT::ID; }
352
353 bool isA(const void *const ClassID) const override {
354 return ClassID == classID() || ParentErrT::isA(ClassID);
355 }
356};
357
358/// Special ErrorInfo subclass representing a list of ErrorInfos.
359/// Instances of this class are constructed by joinError.
360class ErrorList final : public ErrorInfo<ErrorList> {
361 // handleErrors needs to be able to iterate the payload list of an
362 // ErrorList.
363 template <typename... HandlerTs>
364 friend Error handleErrors(Error E, HandlerTs &&... Handlers);
365
366 // joinErrors is implemented in terms of join.
367 friend Error joinErrors(Error, Error);
368
369public:
370 void log(raw_ostream &OS) const override {
371 OS << "Multiple errors:\n";
372 for (auto &ErrPayload : Payloads) {
373 ErrPayload->log(OS);
374 OS << "\n";
375 }
376 }
377
378 std::error_code convertToErrorCode() const override;
379
380 // Used by ErrorInfo::classID.
381 static char ID;
382
383private:
384 ErrorList(std::unique_ptr<ErrorInfoBase> Payload1,
385 std::unique_ptr<ErrorInfoBase> Payload2) {
386 assert(!Payload1->isA<ErrorList>() && !Payload2->isA<ErrorList>() &&((!Payload1->isA<ErrorList>() && !Payload2->
isA<ErrorList>() && "ErrorList constructor payloads should be singleton errors"
) ? static_cast<void> (0) : __assert_fail ("!Payload1->isA<ErrorList>() && !Payload2->isA<ErrorList>() && \"ErrorList constructor payloads should be singleton errors\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 387, __PRETTY_FUNCTION__))
387 "ErrorList constructor payloads should be singleton errors")((!Payload1->isA<ErrorList>() && !Payload2->
isA<ErrorList>() && "ErrorList constructor payloads should be singleton errors"
) ? static_cast<void> (0) : __assert_fail ("!Payload1->isA<ErrorList>() && !Payload2->isA<ErrorList>() && \"ErrorList constructor payloads should be singleton errors\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 387, __PRETTY_FUNCTION__));
388 Payloads.push_back(std::move(Payload1));
389 Payloads.push_back(std::move(Payload2));
390 }
391
392 static Error join(Error E1, Error E2) {
393 if (!E1)
20
←
Taking false branch
→
394 return E2;
395 if (!E2)
21
←
Taking false branch
→
396 return E1;
397 if (E1.isA<ErrorList>()) {
22
←
Assuming the condition is false
→
23
←
Taking false branch
→
398 auto &E1List = static_cast<ErrorList &>(*E1.getPtr());
399 if (E2.isA<ErrorList>()) {
400 auto E2Payload = E2.takePayload();
401 auto &E2List = static_cast<ErrorList &>(*E2Payload);
402 for (auto &Payload : E2List.Payloads)
403 E1List.Payloads.push_back(std::move(Payload));
404 } else
405 E1List.Payloads.push_back(E2.takePayload());
406
407 return E1;
408 }
409 if (E2.isA<ErrorList>()) {
24
←
Assuming the condition is false
→
25
←
Taking false branch
→
410 auto &E2List = static_cast<ErrorList &>(*E2.getPtr());
411 E2List.Payloads.insert(E2List.Payloads.begin(), E1.takePayload());
412 return E2;
413 }
414 return Error(std::unique_ptr<ErrorList>(
27
←
Calling constructor for 'Error'
→
415 new ErrorList(E1.takePayload(), E2.takePayload())));
26
←
Memory is allocated
→
416 }
417
418 std::vector<std::unique_ptr<ErrorInfoBase>> Payloads;
419};
420
421/// Concatenate errors. The resulting Error is unchecked, and contains the
422/// ErrorInfo(s), if any, contained in E1, followed by the
423/// ErrorInfo(s), if any, contained in E2.
424inline Error joinErrors(Error E1, Error E2) {
425 return ErrorList::join(std::move(E1), std::move(E2));
426}
427
428/// Tagged union holding either a T or a Error.
429///
430/// This class parallels ErrorOr, but replaces error_code with Error. Since
431/// Error cannot be copied, this class replaces getError() with
432/// takeError(). It also adds an bool errorIsA<ErrT>() method for testing the
433/// error class type.
434template <class T> class LLVM_NODISCARD[[clang::warn_unused_result]] Expected {
435 template <class T1> friend class ExpectedAsOutParameter;
436 template <class OtherT> friend class Expected;
437
438 static const bool isRef = std::is_reference<T>::value;
439
440 using wrap = std::reference_wrapper<typename std::remove_reference<T>::type>;
441
442 using error_type = std::unique_ptr<ErrorInfoBase>;
443
444public:
445 using storage_type = typename std::conditional<isRef, wrap, T>::type;
446 using value_type = T;
447
448private:
449 using reference = typename std::remove_reference<T>::type &;
450 using const_reference = const typename std::remove_reference<T>::type &;
451 using pointer = typename std::remove_reference<T>::type *;
452 using const_pointer = const typename std::remove_reference<T>::type *;
453
454public:
455 /// Create an Expected<T> error value from the given Error.
456 Expected(Error Err)
457 : HasError(true)
458#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
459 // Expected is unchecked upon construction in Debug builds.
460 , Unchecked(true)
461#endif
462 {
463 assert(Err && "Cannot create Expected<T> from Error success value.")((Err && "Cannot create Expected<T> from Error success value."
) ? static_cast<void> (0) : __assert_fail ("Err && \"Cannot create Expected<T> from Error success value.\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 463, __PRETTY_FUNCTION__));
464 new (getErrorStorage()) error_type(Err.takePayload());
465 }
466
467 /// Forbid to convert from Error::success() implicitly, this avoids having
468 /// Expected<T> foo() { return Error::success(); } which compiles otherwise
469 /// but triggers the assertion above.
470 Expected(ErrorSuccess) = delete;
471
472 /// Create an Expected<T> success value from the given OtherT value, which
473 /// must be convertible to T.
474 template <typename OtherT>
475 Expected(OtherT &&Val,
476 typename std::enable_if<std::is_convertible<OtherT, T>::value>::type
477 * = nullptr)
478 : HasError(false)
479#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
480 // Expected is unchecked upon construction in Debug builds.
481 , Unchecked(true)
482#endif
483 {
484 new (getStorage()) storage_type(std::forward<OtherT>(Val));
485 }
486
487 /// Move construct an Expected<T> value.
488 Expected(Expected &&Other) { moveConstruct(std::move(Other)); }
489
490 /// Move construct an Expected<T> value from an Expected<OtherT>, where OtherT
491 /// must be convertible to T.
492 template <class OtherT>
493 Expected(Expected<OtherT> &&Other,
494 typename std::enable_if<std::is_convertible<OtherT, T>::value>::type
495 * = nullptr) {
496 moveConstruct(std::move(Other));
497 }
498
499 /// Move construct an Expected<T> value from an Expected<OtherT>, where OtherT
500 /// isn't convertible to T.
501 template <class OtherT>
502 explicit Expected(
503 Expected<OtherT> &&Other,
504 typename std::enable_if<!std::is_convertible<OtherT, T>::value>::type * =
505 nullptr) {
506 moveConstruct(std::move(Other));
507 }
508
509 /// Move-assign from another Expected<T>.
510 Expected &operator=(Expected &&Other) {
511 moveAssign(std::move(Other));
512 return *this;
513 }
514
515 /// Destroy an Expected<T>.
516 ~Expected() {
517 assertIsChecked();
518 if (!HasError)
519 getStorage()->~storage_type();
520 else
521 getErrorStorage()->~error_type();
522 }
523
524 /// Return false if there is an error.
525 explicit operator bool() {
526#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
527 Unchecked = HasError;
528#endif
529 return !HasError;
530 }
531
532 /// Returns a reference to the stored T value.
533 reference get() {
534 assertIsChecked();
535 return *getStorage();
536 }
537
538 /// Returns a const reference to the stored T value.
539 const_reference get() const {
540 assertIsChecked();
541 return const_cast<Expected<T> *>(this)->get();
542 }
543
544 /// Check that this Expected<T> is an error of type ErrT.
545 template <typename ErrT> bool errorIsA() const {
546 return HasError && (*getErrorStorage())->template isA<ErrT>();
547 }
548
549 /// Take ownership of the stored error.
550 /// After calling this the Expected<T> is in an indeterminate state that can
551 /// only be safely destructed. No further calls (beside the destructor) should
552 /// be made on the Expected<T> vaule.
553 Error takeError() {
554#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
555 Unchecked = false;
556#endif
557 return HasError ? Error(std::move(*getErrorStorage())) : Error::success();
558 }
559
560 /// Returns a pointer to the stored T value.
561 pointer operator->() {
562 assertIsChecked();
563 return toPointer(getStorage());
564 }
565
566 /// Returns a const pointer to the stored T value.
567 const_pointer operator->() const {
568 assertIsChecked();
569 return toPointer(getStorage());
570 }
571
572 /// Returns a reference to the stored T value.
573 reference operator*() {
574 assertIsChecked();
575 return *getStorage();
576 }
577
578 /// Returns a const reference to the stored T value.
579 const_reference operator*() const {
580 assertIsChecked();
581 return *getStorage();
582 }
583
584private:
585 template <class T1>
586 static bool compareThisIfSameType(const T1 &a, const T1 &b) {
587 return &a == &b;
588 }
589
590 template <class T1, class T2>
591 static bool compareThisIfSameType(const T1 &a, const T2 &b) {
592 return false;
593 }
594
595 template <class OtherT> void moveConstruct(Expected<OtherT> &&Other) {
596 HasError = Other.HasError;
597#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
598 Unchecked = true;
599 Other.Unchecked = false;
600#endif
601
602 if (!HasError)
603 new (getStorage()) storage_type(std::move(*Other.getStorage()));
604 else
605 new (getErrorStorage()) error_type(std::move(*Other.getErrorStorage()));
606 }
607
608 template <class OtherT> void moveAssign(Expected<OtherT> &&Other) {
609 assertIsChecked();
610
611 if (compareThisIfSameType(*this, Other))
612 return;
613
614 this->~Expected();
615 new (this) Expected(std::move(Other));
616 }
617
618 pointer toPointer(pointer Val) { return Val; }
619
620 const_pointer toPointer(const_pointer Val) const { return Val; }
621
622 pointer toPointer(wrap *Val) { return &Val->get(); }
623
624 const_pointer toPointer(const wrap *Val) const { return &Val->get(); }
625
626 storage_type *getStorage() {
627 assert(!HasError && "Cannot get value when an error exists!")((!HasError && "Cannot get value when an error exists!"
) ? static_cast<void> (0) : __assert_fail ("!HasError && \"Cannot get value when an error exists!\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 627, __PRETTY_FUNCTION__));
628 return reinterpret_cast<storage_type *>(TStorage.buffer);
629 }
630
631 const storage_type *getStorage() const {
632 assert(!HasError && "Cannot get value when an error exists!")((!HasError && "Cannot get value when an error exists!"
) ? static_cast<void> (0) : __assert_fail ("!HasError && \"Cannot get value when an error exists!\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 632, __PRETTY_FUNCTION__));
633 return reinterpret_cast<const storage_type *>(TStorage.buffer);
634 }
635
636 error_type *getErrorStorage() {
637 assert(HasError && "Cannot get error when a value exists!")((HasError && "Cannot get error when a value exists!"
) ? static_cast<void> (0) : __assert_fail ("HasError && \"Cannot get error when a value exists!\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 637, __PRETTY_FUNCTION__));
638 return reinterpret_cast<error_type *>(ErrorStorage.buffer);
639 }
640
641 const error_type *getErrorStorage() const {
642 assert(HasError && "Cannot get error when a value exists!")((HasError && "Cannot get error when a value exists!"
) ? static_cast<void> (0) : __assert_fail ("HasError && \"Cannot get error when a value exists!\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 642, __PRETTY_FUNCTION__));
643 return reinterpret_cast<const error_type *>(ErrorStorage.buffer);
644 }
645
646 // Used by ExpectedAsOutParameter to reset the checked flag.
647 void setUnchecked() {
648#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
649 Unchecked = true;
650#endif
651 }
652
653#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
654 LLVM_ATTRIBUTE_NORETURN__attribute__((noreturn))
655 LLVM_ATTRIBUTE_NOINLINE__attribute__((noinline))
656 void fatalUncheckedExpected() const {
657 dbgs() << "Expected<T> must be checked before access or destruction.\n";
658 if (HasError) {
659 dbgs() << "Unchecked Expected<T> contained error:\n";
660 (*getErrorStorage())->log(dbgs());
661 } else
662 dbgs() << "Expected<T> value was in success state. (Note: Expected<T> "
663 "values in success mode must still be checked prior to being "
664 "destroyed).\n";
665 abort();
666 }
667#endif
668
669 void assertIsChecked() {
670#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
671 if (LLVM_UNLIKELY(Unchecked)__builtin_expect((bool)(Unchecked), false))
672 fatalUncheckedExpected();
673#endif
674 }
675
676 union {
677 AlignedCharArrayUnion<storage_type> TStorage;
678 AlignedCharArrayUnion<error_type> ErrorStorage;
679 };
680 bool HasError : 1;
681#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
682 bool Unchecked : 1;
683#endif
684};
685
686/// Report a serious error, calling any installed error handler. See
687/// ErrorHandling.h.
688LLVM_ATTRIBUTE_NORETURN__attribute__((noreturn)) void report_fatal_error(Error Err,
689 bool gen_crash_diag = true);
690
691/// Report a fatal error if Err is a failure value.
692///
693/// This function can be used to wrap calls to fallible functions ONLY when it
694/// is known that the Error will always be a success value. E.g.
695///
696/// @code{.cpp}
697/// // foo only attempts the fallible operation if DoFallibleOperation is
698/// // true. If DoFallibleOperation is false then foo always returns
699/// // Error::success().
700/// Error foo(bool DoFallibleOperation);
701///
702/// cantFail(foo(false));
703/// @endcode
704inline void cantFail(Error Err, const char *Msg = nullptr) {
705 if (Err) {
706 if (!Msg)
707 Msg = "Failure value returned from cantFail wrapped call";
708 llvm_unreachable(Msg)::llvm::llvm_unreachable_internal(Msg, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 708);
709 }
710}
711
712/// Report a fatal error if ValOrErr is a failure value, otherwise unwraps and
713/// returns the contained value.
714///
715/// This function can be used to wrap calls to fallible functions ONLY when it
716/// is known that the Error will always be a success value. E.g.
717///
718/// @code{.cpp}
719/// // foo only attempts the fallible operation if DoFallibleOperation is
720/// // true. If DoFallibleOperation is false then foo always returns an int.
721/// Expected<int> foo(bool DoFallibleOperation);
722///
723/// int X = cantFail(foo(false));
724/// @endcode
725template <typename T>
726T cantFail(Expected<T> ValOrErr, const char *Msg = nullptr) {
727 if (ValOrErr)
728 return std::move(*ValOrErr);
729 else {
730 if (!Msg)
731 Msg = "Failure value returned from cantFail wrapped call";
732 llvm_unreachable(Msg)::llvm::llvm_unreachable_internal(Msg, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 732);
733 }
734}
735
736/// Report a fatal error if ValOrErr is a failure value, otherwise unwraps and
737/// returns the contained reference.
738///
739/// This function can be used to wrap calls to fallible functions ONLY when it
740/// is known that the Error will always be a success value. E.g.
741///
742/// @code{.cpp}
743/// // foo only attempts the fallible operation if DoFallibleOperation is
744/// // true. If DoFallibleOperation is false then foo always returns a Bar&.
745/// Expected<Bar&> foo(bool DoFallibleOperation);
746///
747/// Bar &X = cantFail(foo(false));
748/// @endcode
749template <typename T>
750T& cantFail(Expected<T&> ValOrErr, const char *Msg = nullptr) {
751 if (ValOrErr)
752 return *ValOrErr;
753 else {
754 if (!Msg)
755 Msg = "Failure value returned from cantFail wrapped call";
756 llvm_unreachable(Msg)::llvm::llvm_unreachable_internal(Msg, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 756);
757 }
758}
759
760/// Helper for testing applicability of, and applying, handlers for
761/// ErrorInfo types.
762template <typename HandlerT>
763class ErrorHandlerTraits
764 : public ErrorHandlerTraits<decltype(
765 &std::remove_reference<HandlerT>::type::operator())> {};
766
767// Specialization functions of the form 'Error (const ErrT&)'.
768template <typename ErrT> class ErrorHandlerTraits<Error (&)(ErrT &)> {
769public:
770 static bool appliesTo(const ErrorInfoBase &E) {
771 return E.template isA<ErrT>();
772 }
773
774 template <typename HandlerT>
775 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
776 assert(appliesTo(*E) && "Applying incorrect handler")((appliesTo(*E) && "Applying incorrect handler") ? static_cast
<void> (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 776, __PRETTY_FUNCTION__));
777 return H(static_cast<ErrT &>(*E));
778 }
779};
780
781// Specialization functions of the form 'void (const ErrT&)'.
782template <typename ErrT> class ErrorHandlerTraits<void (&)(ErrT &)> {
783public:
784 static bool appliesTo(const ErrorInfoBase &E) {
785 return E.template isA<ErrT>();
786 }
787
788 template <typename HandlerT>
789 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
790 assert(appliesTo(*E) && "Applying incorrect handler")((appliesTo(*E) && "Applying incorrect handler") ? static_cast
<void> (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 790, __PRETTY_FUNCTION__));
791 H(static_cast<ErrT &>(*E));
792 return Error::success();
793 }
794};
795
796/// Specialization for functions of the form 'Error (std::unique_ptr<ErrT>)'.
797template <typename ErrT>
798class ErrorHandlerTraits<Error (&)(std::unique_ptr<ErrT>)> {
799public:
800 static bool appliesTo(const ErrorInfoBase &E) {
801 return E.template isA<ErrT>();
802 }
803
804 template <typename HandlerT>
805 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
806 assert(appliesTo(*E) && "Applying incorrect handler")((appliesTo(*E) && "Applying incorrect handler") ? static_cast
<void> (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 806, __PRETTY_FUNCTION__));
807 std::unique_ptr<ErrT> SubE(static_cast<ErrT *>(E.release()));
808 return H(std::move(SubE));
809 }
810};
811
812/// Specialization for functions of the form 'void (std::unique_ptr<ErrT>)'.
813template <typename ErrT>
814class ErrorHandlerTraits<void (&)(std::unique_ptr<ErrT>)> {
815public:
816 static bool appliesTo(const ErrorInfoBase &E) {
817 return E.template isA<ErrT>();
818 }
819
820 template <typename HandlerT>
821 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
822 assert(appliesTo(*E) && "Applying incorrect handler")((appliesTo(*E) && "Applying incorrect handler") ? static_cast
<void> (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 822, __PRETTY_FUNCTION__));
823 std::unique_ptr<ErrT> SubE(static_cast<ErrT *>(E.release()));
824 H(std::move(SubE));
825 return Error::success();
826 }
827};
828
829// Specialization for member functions of the form 'RetT (const ErrT&)'.
830template <typename C, typename RetT, typename ErrT>
831class ErrorHandlerTraits<RetT (C::*)(ErrT &)>
832 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
833
834// Specialization for member functions of the form 'RetT (const ErrT&) const'.
835template <typename C, typename RetT, typename ErrT>
836class ErrorHandlerTraits<RetT (C::*)(ErrT &) const>
837 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
838
839// Specialization for member functions of the form 'RetT (const ErrT&)'.
840template <typename C, typename RetT, typename ErrT>
841class ErrorHandlerTraits<RetT (C::*)(const ErrT &)>
842 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
843
844// Specialization for member functions of the form 'RetT (const ErrT&) const'.
845template <typename C, typename RetT, typename ErrT>
846class ErrorHandlerTraits<RetT (C::*)(const ErrT &) const>
847 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
848
849/// Specialization for member functions of the form
850/// 'RetT (std::unique_ptr<ErrT>)'.
851template <typename C, typename RetT, typename ErrT>
852class ErrorHandlerTraits<RetT (C::*)(std::unique_ptr<ErrT>)>
853 : public ErrorHandlerTraits<RetT (&)(std::unique_ptr<ErrT>)> {};
854
855/// Specialization for member functions of the form
856/// 'RetT (std::unique_ptr<ErrT>) const'.
857template <typename C, typename RetT, typename ErrT>
858class ErrorHandlerTraits<RetT (C::*)(std::unique_ptr<ErrT>) const>
859 : public ErrorHandlerTraits<RetT (&)(std::unique_ptr<ErrT>)> {};
860
861inline Error handleErrorImpl(std::unique_ptr<ErrorInfoBase> Payload) {
862 return Error(std::move(Payload));
863}
864
865template <typename HandlerT, typename... HandlerTs>
866Error handleErrorImpl(std::unique_ptr<ErrorInfoBase> Payload,
867 HandlerT &&Handler, HandlerTs &&... Handlers) {
868 if (ErrorHandlerTraits<HandlerT>::appliesTo(*Payload))
869 return ErrorHandlerTraits<HandlerT>::apply(std::forward<HandlerT>(Handler),
870 std::move(Payload));
871 return handleErrorImpl(std::move(Payload),
872 std::forward<HandlerTs>(Handlers)...);
873}
874
875/// Pass the ErrorInfo(s) contained in E to their respective handlers. Any
876/// unhandled errors (or Errors returned by handlers) are re-concatenated and
877/// returned.
878/// Because this function returns an error, its result must also be checked
879/// or returned. If you intend to handle all errors use handleAllErrors
880/// (which returns void, and will abort() on unhandled errors) instead.
881template <typename... HandlerTs>
882Error handleErrors(Error E, HandlerTs &&... Hs) {
883 if (!E)
16
←
Taking false branch
→
884 return Error::success();
885
886 std::unique_ptr<ErrorInfoBase> Payload = E.takePayload();
887
888 if (Payload->isA<ErrorList>()) {
17
←
Assuming the condition is true
→
18
←
Taking true branch
→
889 ErrorList &List = static_cast<ErrorList &>(*Payload);
890 Error R;
891 for (auto &P : List.Payloads)
892 R = ErrorList::join(
19
←
Calling 'ErrorList::join'
→
893 std::move(R),
894 handleErrorImpl(std::move(P), std::forward<HandlerTs>(Hs)...));
895 return R;
896 }
897
898 return handleErrorImpl(std::move(Payload), std::forward<HandlerTs>(Hs)...);
899}
900
901/// Behaves the same as handleErrors, except that by contract all errors
902/// *must* be handled by the given handlers (i.e. there must be no remaining
903/// errors after running the handlers, or llvm_unreachable is called).
904template <typename... HandlerTs>
905void handleAllErrors(Error E, HandlerTs &&... Handlers) {
906 cantFail(handleErrors(std::move(E), std::forward<HandlerTs>(Handlers)...));
15
←
Calling 'handleErrors<(lambda at /build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h:965:33)>'
→
907}
908
909/// Check that E is a non-error, then drop it.
910/// If E is an error, llvm_unreachable will be called.
911inline void handleAllErrors(Error E) {
912 cantFail(std::move(E));
913}
914
915/// Handle any errors (if present) in an Expected<T>, then try a recovery path.
916///
917/// If the incoming value is a success value it is returned unmodified. If it
918/// is a failure value then it the contained error is passed to handleErrors.
919/// If handleErrors is able to handle the error then the RecoveryPath functor
920/// is called to supply the final result. If handleErrors is not able to
921/// handle all errors then the unhandled errors are returned.
922///
923/// This utility enables the follow pattern:
924///
925/// @code{.cpp}
926/// enum FooStrategy { Aggressive, Conservative };
927/// Expected<Foo> foo(FooStrategy S);
928///
929/// auto ResultOrErr =
930/// handleExpected(
931/// foo(Aggressive),
932/// []() { return foo(Conservative); },
933/// [](AggressiveStrategyError&) {
934/// // Implicitly conusme this - we'll recover by using a conservative
935/// // strategy.
936/// });
937///
938/// @endcode
939template <typename T, typename RecoveryFtor, typename... HandlerTs>
940Expected<T> handleExpected(Expected<T> ValOrErr, RecoveryFtor &&RecoveryPath,
941 HandlerTs &&... Handlers) {
942 if (ValOrErr)
943 return ValOrErr;
944
945 if (auto Err = handleErrors(ValOrErr.takeError(),
946 std::forward<HandlerTs>(Handlers)...))
947 return std::move(Err);
948
949 return RecoveryPath();
950}
951
952/// Log all errors (if any) in E to OS. If there are any errors, ErrorBanner
953/// will be printed before the first one is logged. A newline will be printed
954/// after each error.
955///
956/// This is useful in the base level of your program to allow clean termination
957/// (allowing clean deallocation of resources, etc.), while reporting error
958/// information to the user.
959void logAllUnhandledErrors(Error E, raw_ostream &OS, Twine ErrorBanner);
960
961/// Write all error messages (if any) in E to a string. The newline character
962/// is used to separate error messages.
963inline std::string toString(Error E) {
964 SmallVector<std::string, 2> Errors;
965 handleAllErrors(std::move(E), [&Errors](const ErrorInfoBase &EI) {
14
←
Calling 'handleAllErrors<(lambda at /build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h:965:33)>'
→
966 Errors.push_back(EI.message());
967 });
968 return join(Errors.begin(), Errors.end(), "\n");
969}
970
971/// Consume a Error without doing anything. This method should be used
972/// only where an error can be considered a reasonable and expected return
973/// value.
974///
975/// Uses of this method are potentially indicative of design problems: If it's
976/// legitimate to do nothing while processing an "error", the error-producer
977/// might be more clearly refactored to return an Optional<T>.
978inline void consumeError(Error Err) {
979 handleAllErrors(std::move(Err), [](const ErrorInfoBase &) {});
980}
981
982/// Helper for converting an Error to a bool.
983///
984/// This method returns true if Err is in an error state, or false if it is
985/// in a success state. Puts Err in a checked state in both cases (unlike
986/// Error::operator bool(), which only does this for success states).
987inline bool errorToBool(Error Err) {
988 bool IsError = static_cast<bool>(Err);
989 if (IsError)
990 consumeError(std::move(Err));
991 return IsError;
992}
993
994/// Helper for Errors used as out-parameters.
995///
996/// This helper is for use with the Error-as-out-parameter idiom, where an error
997/// is passed to a function or method by reference, rather than being returned.
998/// In such cases it is helpful to set the checked bit on entry to the function
999/// so that the error can be written to (unchecked Errors abort on assignment)
1000/// and clear the checked bit on exit so that clients cannot accidentally forget
1001/// to check the result. This helper performs these actions automatically using
1002/// RAII:
1003///
1004/// @code{.cpp}
1005/// Result foo(Error &Err) {
1006/// ErrorAsOutParameter ErrAsOutParam(&Err); // 'Checked' flag set
1007/// // <body of foo>
1008/// // <- 'Checked' flag auto-cleared when ErrAsOutParam is destructed.
1009/// }
1010/// @endcode
1011///
1012/// ErrorAsOutParameter takes an Error* rather than Error& so that it can be
1013/// used with optional Errors (Error pointers that are allowed to be null). If
1014/// ErrorAsOutParameter took an Error reference, an instance would have to be
1015/// created inside every condition that verified that Error was non-null. By
1016/// taking an Error pointer we can just create one instance at the top of the
1017/// function.
1018class ErrorAsOutParameter {
1019public:
1020 ErrorAsOutParameter(Error *Err) : Err(Err) {
1021 // Raise the checked bit if Err is success.
1022 if (Err)
1023 (void)!!*Err;
1024 }
1025
1026 ~ErrorAsOutParameter() {
1027 // Clear the checked bit.
1028 if (Err && !*Err)
1029 *Err = Error::success();
1030 }
1031
1032private:
1033 Error *Err;
1034};
1035
1036/// Helper for Expected<T>s used as out-parameters.
1037///
1038/// See ErrorAsOutParameter.
1039template <typename T>
1040class ExpectedAsOutParameter {
1041public:
1042 ExpectedAsOutParameter(Expected<T> *ValOrErr)
1043 : ValOrErr(ValOrErr) {
1044 if (ValOrErr)
1045 (void)!!*ValOrErr;
1046 }
1047
1048 ~ExpectedAsOutParameter() {
1049 if (ValOrErr)
1050 ValOrErr->setUnchecked();
1051 }
1052
1053private:
1054 Expected<T> *ValOrErr;
1055};
1056
1057/// This class wraps a std::error_code in a Error.
1058///
1059/// This is useful if you're writing an interface that returns a Error
1060/// (or Expected) and you want to call code that still returns
1061/// std::error_codes.
1062class ECError : public ErrorInfo<ECError> {
1063 friend Error errorCodeToError(std::error_code);
1064
1065public:
1066 void setErrorCode(std::error_code EC) { this->EC = EC; }
1067 std::error_code convertToErrorCode() const override { return EC; }
1068 void log(raw_ostream &OS) const override { OS << EC.message(); }
1069
1070 // Used by ErrorInfo::classID.
1071 static char ID;
1072
1073protected:
1074 ECError() = default;
1075 ECError(std::error_code EC) : EC(EC) {}
1076
1077 std::error_code EC;
1078};
1079
1080/// The value returned by this function can be returned from convertToErrorCode
1081/// for Error values where no sensible translation to std::error_code exists.
1082/// It should only be used in this situation, and should never be used where a
1083/// sensible conversion to std::error_code is available, as attempts to convert
1084/// to/from this error will result in a fatal error. (i.e. it is a programmatic
1085///error to try to convert such a value).
1086std::error_code inconvertibleErrorCode();
1087
1088/// Helper for converting an std::error_code to a Error.
1089Error errorCodeToError(std::error_code EC);
1090
1091/// Helper for converting an ECError to a std::error_code.
1092///
1093/// This method requires that Err be Error() or an ECError, otherwise it
1094/// will trigger a call to abort().
1095std::error_code errorToErrorCode(Error Err);
1096
1097/// Convert an ErrorOr<T> to an Expected<T>.
1098template <typename T> Expected<T> errorOrToExpected(ErrorOr<T> &&EO) {
1099 if (auto EC = EO.getError())
1100 return errorCodeToError(EC);
1101 return std::move(*EO);
1102}
1103
1104/// Convert an Expected<T> to an ErrorOr<T>.
1105template <typename T> ErrorOr<T> expectedToErrorOr(Expected<T> &&E) {
1106 if (auto Err = E.takeError())
1107 return errorToErrorCode(std::move(Err));
1108 return std::move(*E);
1109}
1110
1111/// This class wraps a string in an Error.
1112///
1113/// StringError is useful in cases where the client is not expected to be able
1114/// to consume the specific error message programmatically (for example, if the
1115/// error message is to be presented to the user).
1116///
1117/// StringError can also be used when additional information is to be printed
1118/// along with a error_code message. Depending on the constructor called, this
1119/// class can either display:
1120/// 1. the error_code message (ECError behavior)
1121/// 2. a string
1122/// 3. the error_code message and a string
1123///
1124/// These behaviors are useful when subtyping is required; for example, when a
1125/// specific library needs an explicit error type. In the example below,
1126/// PDBError is derived from StringError:
1127///
1128/// @code{.cpp}
1129/// Expected<int> foo() {
1130/// return llvm::make_error<PDBError>(pdb_error_code::dia_failed_loading,
1131/// "Additional information");
1132/// }
1133/// @endcode
1134///
1135class StringError : public ErrorInfo<StringError> {
1136public:
1137 static char ID;
1138
1139 // Prints EC + S and converts to EC
1140 StringError(std::error_code EC, const Twine &S = Twine());
1141
1142 // Prints S and converts to EC
1143 StringError(const Twine &S, std::error_code EC);
1144
1145 void log(raw_ostream &OS) const override;
1146 std::error_code convertToErrorCode() const override;
1147
1148 const std::string &getMessage() const { return Msg; }
1149
1150private:
1151 std::string Msg;
1152 std::error_code EC;
1153 const bool PrintMsgOnly = false;
1154};
1155
1156/// Create formatted StringError object.
1157template <typename... Ts>
1158Error createStringError(std::error_code EC, char const *Fmt,
1159 const Ts &... Vals) {
1160 std::string Buffer;
1161 raw_string_ostream Stream(Buffer);
1162 Stream << format(Fmt, Vals...);
1163 return make_error<StringError>(Stream.str(), EC);
1164}
1165
1166Error createStringError(std::error_code EC, char const *Msg);
1167
1168/// This class wraps a filename and another Error.
1169///
1170/// In some cases, an error needs to live along a 'source' name, in order to
1171/// show more detailed information to the user.
1172class FileError final : public ErrorInfo<FileError> {
1173
1174 friend Error createFileError(std::string, Error);
1175
1176public:
1177 void log(raw_ostream &OS) const override {
1178 assert(Err && !FileName.empty() && "Trying to log after takeError().")((Err && !FileName.empty() && "Trying to log after takeError()."
) ? static_cast<void> (0) : __assert_fail ("Err && !FileName.empty() && \"Trying to log after takeError().\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 1178, __PRETTY_FUNCTION__));
1179 OS << "'" << FileName << "': ";
1180 Err->log(OS);
1181 }
1182
1183 Error takeError() { return Error(std::move(Err)); }
1184
1185 std::error_code convertToErrorCode() const override;
1186
1187 // Used by ErrorInfo::classID.
1188 static char ID;
1189
1190private:
1191 FileError(std::string F, std::unique_ptr<ErrorInfoBase> E) {
1192 assert(E && "Cannot create FileError from Error success value.")((E && "Cannot create FileError from Error success value."
) ? static_cast<void> (0) : __assert_fail ("E && \"Cannot create FileError from Error success value.\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 1192, __PRETTY_FUNCTION__));
1193 assert(!F.empty() &&((!F.empty() && "The file name provided to FileError must not be empty."
) ? static_cast<void> (0) : __assert_fail ("!F.empty() && \"The file name provided to FileError must not be empty.\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 1194, __PRETTY_FUNCTION__))
1194 "The file name provided to FileError must not be empty.")((!F.empty() && "The file name provided to FileError must not be empty."
) ? static_cast<void> (0) : __assert_fail ("!F.empty() && \"The file name provided to FileError must not be empty.\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 1194, __PRETTY_FUNCTION__));
1195 FileName = F;
1196 Err = std::move(E);
1197 }
1198
1199 static Error build(std::string F, Error E) {
1200 return Error(std::unique_ptr<FileError>(new FileError(F, E.takePayload())));
1201 }
1202
1203 std::string FileName;
1204 std::unique_ptr<ErrorInfoBase> Err;
1205};
1206
1207/// Concatenate a source file path and/or name with an Error. The resulting
1208/// Error is unchecked.
1209inline Error createFileError(std::string F, Error E) {
1210 return FileError::build(F, std::move(E));
1211}
1212
1213Error createFileError(std::string F, ErrorSuccess) = delete;
1214
1215/// Helper for check-and-exit error handling.
1216///
1217/// For tool use only. NOT FOR USE IN LIBRARY CODE.
1218///
1219class ExitOnError {
1220public:
1221 /// Create an error on exit helper.
1222 ExitOnError(std::string Banner = "", int DefaultErrorExitCode = 1)
1223 : Banner(std::move(Banner)),
1224 GetExitCode([=](const Error &) { return DefaultErrorExitCode; }) {}
1225
1226 /// Set the banner string for any errors caught by operator().
1227 void setBanner(std::string Banner) { this->Banner = std::move(Banner); }
1228
1229 /// Set the exit-code mapper function.
1230 void setExitCodeMapper(std::function<int(const Error &)> GetExitCode) {
1231 this->GetExitCode = std::move(GetExitCode);
1232 }
1233
1234 /// Check Err. If it's in a failure state log the error(s) and exit.
1235 void operator()(Error Err) const { checkError(std::move(Err)); }
1236
1237 /// Check E. If it's in a success state then return the contained value. If
1238 /// it's in a failure state log the error(s) and exit.
1239 template <typename T> T operator()(Expected<T> &&E) const {
1240 checkError(E.takeError());
1241 return std::move(*E);
1242 }
1243
1244 /// Check E. If it's in a success state then return the contained reference. If
1245 /// it's in a failure state log the error(s) and exit.
1246 template <typename T> T& operator()(Expected<T&> &&E) const {
1247 checkError(E.takeError());
1248 return *E;
1249 }
1250
1251private:
1252 void checkError(Error Err) const {
1253 if (Err) {
1254 int ExitCode = GetExitCode(Err);
1255 logAllUnhandledErrors(std::move(Err), errs(), Banner);
1256 exit(ExitCode);
1257 }
1258 }
1259
1260 std::string Banner;
1261 std::function<int(const Error &)> GetExitCode;
1262};
1263
1264/// Conversion from Error to LLVMErrorRef for C error bindings.
1265inline LLVMErrorRef wrap(Error Err) {
1266 return reinterpret_cast<LLVMErrorRef>(Err.takePayload().release());
1267}
1268
1269/// Conversion from LLVMErrorRef to Error for C error bindings.
1270inline Error unwrap(LLVMErrorRef ErrRef) {
1271 return Error(std::unique_ptr<ErrorInfoBase>(
1272 reinterpret_cast<ErrorInfoBase *>(ErrRef)));
1273}
1274
1275} // end namespace llvm
1276
1277#endif // LLVM_SUPPORT_ERROR_H