1 //===- Preprocessor.cpp - C Language Family Preprocessor Implementation ---===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file implements the Preprocessor interface.
10 //
11 //===----------------------------------------------------------------------===//
12 //
13 // Options to support:
14 // -H - Print the name of each header file used.
15 // -d[DNI] - Dump various things.
16 // -fworking-directory - #line's with preprocessor's working dir.
17 // -fpreprocessed
18 // -dependency-file,-M,-MM,-MF,-MG,-MP,-MT,-MQ,-MD,-MMD
19 // -W*
20 // -w
21 //
22 // Messages to emit:
23 // "Multiple include guards may be useful for:\n"
24 //
25 //===----------------------------------------------------------------------===//
26
27 #include "clang/Lex/Preprocessor.h"
28 #include "clang/Basic/Builtins.h"
29 #include "clang/Basic/FileManager.h"
30 #include "clang/Basic/FileSystemStatCache.h"
31 #include "clang/Basic/IdentifierTable.h"
32 #include "clang/Basic/LLVM.h"
33 #include "clang/Basic/LangOptions.h"
34 #include "clang/Basic/Module.h"
35 #include "clang/Basic/SourceLocation.h"
36 #include "clang/Basic/SourceManager.h"
37 #include "clang/Basic/TargetInfo.h"
38 #include "clang/Lex/CodeCompletionHandler.h"
39 #include "clang/Lex/ExternalPreprocessorSource.h"
40 #include "clang/Lex/HeaderSearch.h"
41 #include "clang/Lex/LexDiagnostic.h"
42 #include "clang/Lex/Lexer.h"
43 #include "clang/Lex/LiteralSupport.h"
44 #include "clang/Lex/MacroArgs.h"
45 #include "clang/Lex/MacroInfo.h"
46 #include "clang/Lex/ModuleLoader.h"
47 #include "clang/Lex/Pragma.h"
48 #include "clang/Lex/PreprocessingRecord.h"
49 #include "clang/Lex/PreprocessorLexer.h"
50 #include "clang/Lex/PreprocessorOptions.h"
51 #include "clang/Lex/ScratchBuffer.h"
52 #include "clang/Lex/Token.h"
53 #include "clang/Lex/TokenLexer.h"
54 #include "llvm/ADT/APInt.h"
55 #include "llvm/ADT/ArrayRef.h"
56 #include "llvm/ADT/DenseMap.h"
57 #include "llvm/ADT/STLExtras.h"
58 #include "llvm/ADT/SmallString.h"
59 #include "llvm/ADT/SmallVector.h"
60 #include "llvm/ADT/StringRef.h"
61 #include "llvm/ADT/StringSwitch.h"
62 #include "llvm/Support/Capacity.h"
63 #include "llvm/Support/ErrorHandling.h"
64 #include "llvm/Support/MemoryBuffer.h"
65 #include "llvm/Support/raw_ostream.h"
66 #include <algorithm>
67 #include <cassert>
68 #include <memory>
69 #include <string>
70 #include <utility>
71 #include <vector>
72
73 using namespace clang;
74
75 LLVM_INSTANTIATE_REGISTRY(PragmaHandlerRegistry)
76
77 ExternalPreprocessorSource::~ExternalPreprocessorSource() = default;
78
Preprocessor(std::shared_ptr<PreprocessorOptions> PPOpts,DiagnosticsEngine & diags,LangOptions & opts,SourceManager & SM,HeaderSearch & Headers,ModuleLoader & TheModuleLoader,IdentifierInfoLookup * IILookup,bool OwnsHeaders,TranslationUnitKind TUKind)79 Preprocessor::Preprocessor(std::shared_ptr<PreprocessorOptions> PPOpts,
80 DiagnosticsEngine &diags, LangOptions &opts,
81 SourceManager &SM, HeaderSearch &Headers,
82 ModuleLoader &TheModuleLoader,
83 IdentifierInfoLookup *IILookup, bool OwnsHeaders,
84 TranslationUnitKind TUKind)
85 : PPOpts(std::move(PPOpts)), Diags(&diags), LangOpts(opts),
86 FileMgr(Headers.getFileMgr()), SourceMgr(SM),
87 ScratchBuf(new ScratchBuffer(SourceMgr)), HeaderInfo(Headers),
88 TheModuleLoader(TheModuleLoader), ExternalSource(nullptr),
89 // As the language options may have not been loaded yet (when
90 // deserializing an ASTUnit), adding keywords to the identifier table is
91 // deferred to Preprocessor::Initialize().
92 Identifiers(IILookup), PragmaHandlers(new PragmaNamespace(StringRef())),
93 TUKind(TUKind), SkipMainFilePreamble(0, true),
94 CurSubmoduleState(&NullSubmoduleState) {
95 OwnsHeaderSearch = OwnsHeaders;
96
97 // Default to discarding comments.
98 KeepComments = false;
99 KeepMacroComments = false;
100 SuppressIncludeNotFoundError = false;
101
102 // Macro expansion is enabled.
103 DisableMacroExpansion = false;
104 MacroExpansionInDirectivesOverride = false;
105 InMacroArgs = false;
106 ArgMacro = nullptr;
107 InMacroArgPreExpansion = false;
108 NumCachedTokenLexers = 0;
109 PragmasEnabled = true;
110 ParsingIfOrElifDirective = false;
111 PreprocessedOutput = false;
112
113 // We haven't read anything from the external source.
114 ReadMacrosFromExternalSource = false;
115
116 BuiltinInfo = std::make_unique<Builtin::Context>();
117
118 // "Poison" __VA_ARGS__, __VA_OPT__ which can only appear in the expansion of
119 // a macro. They get unpoisoned where it is allowed.
120 (Ident__VA_ARGS__ = getIdentifierInfo("__VA_ARGS__"))->setIsPoisoned();
121 SetPoisonReason(Ident__VA_ARGS__,diag::ext_pp_bad_vaargs_use);
122 if (getLangOpts().CPlusPlus20) {
123 (Ident__VA_OPT__ = getIdentifierInfo("__VA_OPT__"))->setIsPoisoned();
124 SetPoisonReason(Ident__VA_OPT__,diag::ext_pp_bad_vaopt_use);
125 } else {
126 Ident__VA_OPT__ = nullptr;
127 }
128
129 // Initialize the pragma handlers.
130 RegisterBuiltinPragmas();
131
132 // Initialize builtin macros like __LINE__ and friends.
133 RegisterBuiltinMacros();
134
135 if(LangOpts.Borland) {
136 Ident__exception_info = getIdentifierInfo("_exception_info");
137 Ident___exception_info = getIdentifierInfo("__exception_info");
138 Ident_GetExceptionInfo = getIdentifierInfo("GetExceptionInformation");
139 Ident__exception_code = getIdentifierInfo("_exception_code");
140 Ident___exception_code = getIdentifierInfo("__exception_code");
141 Ident_GetExceptionCode = getIdentifierInfo("GetExceptionCode");
142 Ident__abnormal_termination = getIdentifierInfo("_abnormal_termination");
143 Ident___abnormal_termination = getIdentifierInfo("__abnormal_termination");
144 Ident_AbnormalTermination = getIdentifierInfo("AbnormalTermination");
145 } else {
146 Ident__exception_info = Ident__exception_code = nullptr;
147 Ident__abnormal_termination = Ident___exception_info = nullptr;
148 Ident___exception_code = Ident___abnormal_termination = nullptr;
149 Ident_GetExceptionInfo = Ident_GetExceptionCode = nullptr;
150 Ident_AbnormalTermination = nullptr;
151 }
152
153 // If using a PCH where a #pragma hdrstop is expected, start skipping tokens.
154 if (usingPCHWithPragmaHdrStop())
155 SkippingUntilPragmaHdrStop = true;
156
157 // If using a PCH with a through header, start skipping tokens.
158 if (!this->PPOpts->PCHThroughHeader.empty() &&
159 !this->PPOpts->ImplicitPCHInclude.empty())
160 SkippingUntilPCHThroughHeader = true;
161
162 if (this->PPOpts->GeneratePreamble)
163 PreambleConditionalStack.startRecording();
164
165 ExcludedConditionalDirectiveSkipMappings =
166 this->PPOpts->ExcludedConditionalDirectiveSkipMappings;
167 if (ExcludedConditionalDirectiveSkipMappings)
168 ExcludedConditionalDirectiveSkipMappings->clear();
169
170 MaxTokens = LangOpts.MaxTokens;
171 }
172
~Preprocessor()173 Preprocessor::~Preprocessor() {
174 assert(BacktrackPositions.empty() && "EnableBacktrack/Backtrack imbalance!");
175
176 IncludeMacroStack.clear();
177
178 // Destroy any macro definitions.
179 while (MacroInfoChain *I = MIChainHead) {
180 MIChainHead = I->Next;
181 I->~MacroInfoChain();
182 }
183
184 // Free any cached macro expanders.
185 // This populates MacroArgCache, so all TokenLexers need to be destroyed
186 // before the code below that frees up the MacroArgCache list.
187 std::fill(TokenLexerCache, TokenLexerCache + NumCachedTokenLexers, nullptr);
188 CurTokenLexer.reset();
189
190 // Free any cached MacroArgs.
191 for (MacroArgs *ArgList = MacroArgCache; ArgList;)
192 ArgList = ArgList->deallocate();
193
194 // Delete the header search info, if we own it.
195 if (OwnsHeaderSearch)
196 delete &HeaderInfo;
197 }
198
Initialize(const TargetInfo & Target,const TargetInfo * AuxTarget)199 void Preprocessor::Initialize(const TargetInfo &Target,
200 const TargetInfo *AuxTarget) {
201 assert((!this->Target || this->Target == &Target) &&
202 "Invalid override of target information");
203 this->Target = &Target;
204
205 assert((!this->AuxTarget || this->AuxTarget == AuxTarget) &&
206 "Invalid override of aux target information.");
207 this->AuxTarget = AuxTarget;
208
209 // Initialize information about built-ins.
210 BuiltinInfo->InitializeTarget(Target, AuxTarget);
211 HeaderInfo.setTarget(Target);
212
213 // Populate the identifier table with info about keywords for the current language.
214 Identifiers.AddKeywords(LangOpts);
215 }
216
InitializeForModelFile()217 void Preprocessor::InitializeForModelFile() {
218 NumEnteredSourceFiles = 0;
219
220 // Reset pragmas
221 PragmaHandlersBackup = std::move(PragmaHandlers);
222 PragmaHandlers = std::make_unique<PragmaNamespace>(StringRef());
223 RegisterBuiltinPragmas();
224
225 // Reset PredefinesFileID
226 PredefinesFileID = FileID();
227 }
228
FinalizeForModelFile()229 void Preprocessor::FinalizeForModelFile() {
230 NumEnteredSourceFiles = 1;
231
232 PragmaHandlers = std::move(PragmaHandlersBackup);
233 }
234
DumpToken(const Token & Tok,bool DumpFlags) const235 void Preprocessor::DumpToken(const Token &Tok, bool DumpFlags) const {
236 llvm::errs() << tok::getTokenName(Tok.getKind()) << " '"
237 << getSpelling(Tok) << "'";
238
239 if (!DumpFlags) return;
240
241 llvm::errs() << "\t";
242 if (Tok.isAtStartOfLine())
243 llvm::errs() << " [StartOfLine]";
244 if (Tok.hasLeadingSpace())
245 llvm::errs() << " [LeadingSpace]";
246 if (Tok.isExpandDisabled())
247 llvm::errs() << " [ExpandDisabled]";
248 if (Tok.needsCleaning()) {
249 const char *Start = SourceMgr.getCharacterData(Tok.getLocation());
250 llvm::errs() << " [UnClean='" << StringRef(Start, Tok.getLength())
251 << "']";
252 }
253
254 llvm::errs() << "\tLoc=<";
255 DumpLocation(Tok.getLocation());
256 llvm::errs() << ">";
257 }
258
DumpLocation(SourceLocation Loc) const259 void Preprocessor::DumpLocation(SourceLocation Loc) const {
260 Loc.print(llvm::errs(), SourceMgr);
261 }
262
DumpMacro(const MacroInfo & MI) const263 void Preprocessor::DumpMacro(const MacroInfo &MI) const {
264 llvm::errs() << "MACRO: ";
265 for (unsigned i = 0, e = MI.getNumTokens(); i != e; ++i) {
266 DumpToken(MI.getReplacementToken(i));
267 llvm::errs() << " ";
268 }
269 llvm::errs() << "\n";
270 }
271
PrintStats()272 void Preprocessor::PrintStats() {
273 llvm::errs() << "\n*** Preprocessor Stats:\n";
274 llvm::errs() << NumDirectives << " directives found:\n";
275 llvm::errs() << " " << NumDefined << " #define.\n";
276 llvm::errs() << " " << NumUndefined << " #undef.\n";
277 llvm::errs() << " #include/#include_next/#import:\n";
278 llvm::errs() << " " << NumEnteredSourceFiles << " source files entered.\n";
279 llvm::errs() << " " << MaxIncludeStackDepth << " max include stack depth\n";
280 llvm::errs() << " " << NumIf << " #if/#ifndef/#ifdef.\n";
281 llvm::errs() << " " << NumElse << " #else/#elif.\n";
282 llvm::errs() << " " << NumEndif << " #endif.\n";
283 llvm::errs() << " " << NumPragma << " #pragma.\n";
284 llvm::errs() << NumSkipped << " #if/#ifndef#ifdef regions skipped\n";
285
286 llvm::errs() << NumMacroExpanded << "/" << NumFnMacroExpanded << "/"
287 << NumBuiltinMacroExpanded << " obj/fn/builtin macros expanded, "
288 << NumFastMacroExpanded << " on the fast path.\n";
289 llvm::errs() << (NumFastTokenPaste+NumTokenPaste)
290 << " token paste (##) operations performed, "
291 << NumFastTokenPaste << " on the fast path.\n";
292
293 llvm::errs() << "\nPreprocessor Memory: " << getTotalMemory() << "B total";
294
295 llvm::errs() << "\n BumpPtr: " << BP.getTotalMemory();
296 llvm::errs() << "\n Macro Expanded Tokens: "
297 << llvm::capacity_in_bytes(MacroExpandedTokens);
298 llvm::errs() << "\n Predefines Buffer: " << Predefines.capacity();
299 // FIXME: List information for all submodules.
300 llvm::errs() << "\n Macros: "
301 << llvm::capacity_in_bytes(CurSubmoduleState->Macros);
302 llvm::errs() << "\n #pragma push_macro Info: "
303 << llvm::capacity_in_bytes(PragmaPushMacroInfo);
304 llvm::errs() << "\n Poison Reasons: "
305 << llvm::capacity_in_bytes(PoisonReasons);
306 llvm::errs() << "\n Comment Handlers: "
307 << llvm::capacity_in_bytes(CommentHandlers) << "\n";
308 }
309
310 Preprocessor::macro_iterator
macro_begin(bool IncludeExternalMacros) const311 Preprocessor::macro_begin(bool IncludeExternalMacros) const {
312 if (IncludeExternalMacros && ExternalSource &&
313 !ReadMacrosFromExternalSource) {
314 ReadMacrosFromExternalSource = true;
315 ExternalSource->ReadDefinedMacros();
316 }
317
318 // Make sure we cover all macros in visible modules.
319 for (const ModuleMacro &Macro : ModuleMacros)
320 CurSubmoduleState->Macros.insert(std::make_pair(Macro.II, MacroState()));
321
322 return CurSubmoduleState->Macros.begin();
323 }
324
getTotalMemory() const325 size_t Preprocessor::getTotalMemory() const {
326 return BP.getTotalMemory()
327 + llvm::capacity_in_bytes(MacroExpandedTokens)
328 + Predefines.capacity() /* Predefines buffer. */
329 // FIXME: Include sizes from all submodules, and include MacroInfo sizes,
330 // and ModuleMacros.
331 + llvm::capacity_in_bytes(CurSubmoduleState->Macros)
332 + llvm::capacity_in_bytes(PragmaPushMacroInfo)
333 + llvm::capacity_in_bytes(PoisonReasons)
334 + llvm::capacity_in_bytes(CommentHandlers);
335 }
336
337 Preprocessor::macro_iterator
macro_end(bool IncludeExternalMacros) const338 Preprocessor::macro_end(bool IncludeExternalMacros) const {
339 if (IncludeExternalMacros && ExternalSource &&
340 !ReadMacrosFromExternalSource) {
341 ReadMacrosFromExternalSource = true;
342 ExternalSource->ReadDefinedMacros();
343 }
344
345 return CurSubmoduleState->Macros.end();
346 }
347
348 /// Compares macro tokens with a specified token value sequence.
MacroDefinitionEquals(const MacroInfo * MI,ArrayRef<TokenValue> Tokens)349 static bool MacroDefinitionEquals(const MacroInfo *MI,
350 ArrayRef<TokenValue> Tokens) {
351 return Tokens.size() == MI->getNumTokens() &&
352 std::equal(Tokens.begin(), Tokens.end(), MI->tokens_begin());
353 }
354
getLastMacroWithSpelling(SourceLocation Loc,ArrayRef<TokenValue> Tokens) const355 StringRef Preprocessor::getLastMacroWithSpelling(
356 SourceLocation Loc,
357 ArrayRef<TokenValue> Tokens) const {
358 SourceLocation BestLocation;
359 StringRef BestSpelling;
360 for (Preprocessor::macro_iterator I = macro_begin(), E = macro_end();
361 I != E; ++I) {
362 const MacroDirective::DefInfo
363 Def = I->second.findDirectiveAtLoc(Loc, SourceMgr);
364 if (!Def || !Def.getMacroInfo())
365 continue;
366 if (!Def.getMacroInfo()->isObjectLike())
367 continue;
368 if (!MacroDefinitionEquals(Def.getMacroInfo(), Tokens))
369 continue;
370 SourceLocation Location = Def.getLocation();
371 // Choose the macro defined latest.
372 if (BestLocation.isInvalid() ||
373 (Location.isValid() &&
374 SourceMgr.isBeforeInTranslationUnit(BestLocation, Location))) {
375 BestLocation = Location;
376 BestSpelling = I->first->getName();
377 }
378 }
379 return BestSpelling;
380 }
381
recomputeCurLexerKind()382 void Preprocessor::recomputeCurLexerKind() {
383 if (CurLexer)
384 CurLexerKind = CLK_Lexer;
385 else if (CurTokenLexer)
386 CurLexerKind = CLK_TokenLexer;
387 else
388 CurLexerKind = CLK_CachingLexer;
389 }
390
SetCodeCompletionPoint(const FileEntry * File,unsigned CompleteLine,unsigned CompleteColumn)391 bool Preprocessor::SetCodeCompletionPoint(const FileEntry *File,
392 unsigned CompleteLine,
393 unsigned CompleteColumn) {
394 assert(File);
395 assert(CompleteLine && CompleteColumn && "Starts from 1:1");
396 assert(!CodeCompletionFile && "Already set");
397
398 // Load the actual file's contents.
399 Optional<llvm::MemoryBufferRef> Buffer =
400 SourceMgr.getMemoryBufferForFileOrNone(File);
401 if (!Buffer)
402 return true;
403
404 // Find the byte position of the truncation point.
405 const char *Position = Buffer->getBufferStart();
406 for (unsigned Line = 1; Line < CompleteLine; ++Line) {
407 for (; *Position; ++Position) {
408 if (*Position != '\r' && *Position != '\n')
409 continue;
410
411 // Eat \r\n or \n\r as a single line.
412 if ((Position[1] == '\r' || Position[1] == '\n') &&
413 Position[0] != Position[1])
414 ++Position;
415 ++Position;
416 break;
417 }
418 }
419
420 Position += CompleteColumn - 1;
421
422 // If pointing inside the preamble, adjust the position at the beginning of
423 // the file after the preamble.
424 if (SkipMainFilePreamble.first &&
425 SourceMgr.getFileEntryForID(SourceMgr.getMainFileID()) == File) {
426 if (Position - Buffer->getBufferStart() < SkipMainFilePreamble.first)
427 Position = Buffer->getBufferStart() + SkipMainFilePreamble.first;
428 }
429
430 if (Position > Buffer->getBufferEnd())
431 Position = Buffer->getBufferEnd();
432
433 CodeCompletionFile = File;
434 CodeCompletionOffset = Position - Buffer->getBufferStart();
435
436 auto NewBuffer = llvm::WritableMemoryBuffer::getNewUninitMemBuffer(
437 Buffer->getBufferSize() + 1, Buffer->getBufferIdentifier());
438 char *NewBuf = NewBuffer->getBufferStart();
439 char *NewPos = std::copy(Buffer->getBufferStart(), Position, NewBuf);
440 *NewPos = '\0';
441 std::copy(Position, Buffer->getBufferEnd(), NewPos+1);
442 SourceMgr.overrideFileContents(File, std::move(NewBuffer));
443
444 return false;
445 }
446
CodeCompleteIncludedFile(llvm::StringRef Dir,bool IsAngled)447 void Preprocessor::CodeCompleteIncludedFile(llvm::StringRef Dir,
448 bool IsAngled) {
449 if (CodeComplete)
450 CodeComplete->CodeCompleteIncludedFile(Dir, IsAngled);
451 setCodeCompletionReached();
452 }
453
CodeCompleteNaturalLanguage()454 void Preprocessor::CodeCompleteNaturalLanguage() {
455 if (CodeComplete)
456 CodeComplete->CodeCompleteNaturalLanguage();
457 setCodeCompletionReached();
458 }
459
460 /// getSpelling - This method is used to get the spelling of a token into a
461 /// SmallVector. Note that the returned StringRef may not point to the
462 /// supplied buffer if a copy can be avoided.
getSpelling(const Token & Tok,SmallVectorImpl<char> & Buffer,bool * Invalid) const463 StringRef Preprocessor::getSpelling(const Token &Tok,
464 SmallVectorImpl<char> &Buffer,
465 bool *Invalid) const {
466 // NOTE: this has to be checked *before* testing for an IdentifierInfo.
467 if (Tok.isNot(tok::raw_identifier) && !Tok.hasUCN()) {
468 // Try the fast path.
469 if (const IdentifierInfo *II = Tok.getIdentifierInfo())
470 return II->getName();
471 }
472
473 // Resize the buffer if we need to copy into it.
474 if (Tok.needsCleaning())
475 Buffer.resize(Tok.getLength());
476
477 const char *Ptr = Buffer.data();
478 unsigned Len = getSpelling(Tok, Ptr, Invalid);
479 return StringRef(Ptr, Len);
480 }
481
482 /// CreateString - Plop the specified string into a scratch buffer and return a
483 /// location for it. If specified, the source location provides a source
484 /// location for the token.
CreateString(StringRef Str,Token & Tok,SourceLocation ExpansionLocStart,SourceLocation ExpansionLocEnd)485 void Preprocessor::CreateString(StringRef Str, Token &Tok,
486 SourceLocation ExpansionLocStart,
487 SourceLocation ExpansionLocEnd) {
488 Tok.setLength(Str.size());
489
490 const char *DestPtr;
491 SourceLocation Loc = ScratchBuf->getToken(Str.data(), Str.size(), DestPtr);
492
493 if (ExpansionLocStart.isValid())
494 Loc = SourceMgr.createExpansionLoc(Loc, ExpansionLocStart,
495 ExpansionLocEnd, Str.size());
496 Tok.setLocation(Loc);
497
498 // If this is a raw identifier or a literal token, set the pointer data.
499 if (Tok.is(tok::raw_identifier))
500 Tok.setRawIdentifierData(DestPtr);
501 else if (Tok.isLiteral())
502 Tok.setLiteralData(DestPtr);
503 }
504
SplitToken(SourceLocation Loc,unsigned Length)505 SourceLocation Preprocessor::SplitToken(SourceLocation Loc, unsigned Length) {
506 auto &SM = getSourceManager();
507 SourceLocation SpellingLoc = SM.getSpellingLoc(Loc);
508 std::pair<FileID, unsigned> LocInfo = SM.getDecomposedLoc(SpellingLoc);
509 bool Invalid = false;
510 StringRef Buffer = SM.getBufferData(LocInfo.first, &Invalid);
511 if (Invalid)
512 return SourceLocation();
513
514 // FIXME: We could consider re-using spelling for tokens we see repeatedly.
515 const char *DestPtr;
516 SourceLocation Spelling =
517 ScratchBuf->getToken(Buffer.data() + LocInfo.second, Length, DestPtr);
518 return SM.createTokenSplitLoc(Spelling, Loc, Loc.getLocWithOffset(Length));
519 }
520
getCurrentModule()521 Module *Preprocessor::getCurrentModule() {
522 if (!getLangOpts().isCompilingModule())
523 return nullptr;
524
525 return getHeaderSearchInfo().lookupModule(getLangOpts().CurrentModule);
526 }
527
528 //===----------------------------------------------------------------------===//
529 // Preprocessor Initialization Methods
530 //===----------------------------------------------------------------------===//
531
532 /// EnterMainSourceFile - Enter the specified FileID as the main source file,
533 /// which implicitly adds the builtin defines etc.
EnterMainSourceFile()534 void Preprocessor::EnterMainSourceFile() {
535 // We do not allow the preprocessor to reenter the main file. Doing so will
536 // cause FileID's to accumulate information from both runs (e.g. #line
537 // information) and predefined macros aren't guaranteed to be set properly.
538 assert(NumEnteredSourceFiles == 0 && "Cannot reenter the main file!");
539 FileID MainFileID = SourceMgr.getMainFileID();
540
541 // If MainFileID is loaded it means we loaded an AST file, no need to enter
542 // a main file.
543 if (!SourceMgr.isLoadedFileID(MainFileID)) {
544 // Enter the main file source buffer.
545 EnterSourceFile(MainFileID, nullptr, SourceLocation());
546
547 // If we've been asked to skip bytes in the main file (e.g., as part of a
548 // precompiled preamble), do so now.
549 if (SkipMainFilePreamble.first > 0)
550 CurLexer->SetByteOffset(SkipMainFilePreamble.first,
551 SkipMainFilePreamble.second);
552
553 // Tell the header info that the main file was entered. If the file is later
554 // #imported, it won't be re-entered.
555 if (const FileEntry *FE = SourceMgr.getFileEntryForID(MainFileID))
556 HeaderInfo.IncrementIncludeCount(FE);
557 }
558
559 // Preprocess Predefines to populate the initial preprocessor state.
560 std::unique_ptr<llvm::MemoryBuffer> SB =
561 llvm::MemoryBuffer::getMemBufferCopy(Predefines, "<built-in>");
562 assert(SB && "Cannot create predefined source buffer");
563 FileID FID = SourceMgr.createFileID(std::move(SB));
564 assert(FID.isValid() && "Could not create FileID for predefines?");
565 setPredefinesFileID(FID);
566
567 // Start parsing the predefines.
568 EnterSourceFile(FID, nullptr, SourceLocation());
569
570 if (!PPOpts->PCHThroughHeader.empty()) {
571 // Lookup and save the FileID for the through header. If it isn't found
572 // in the search path, it's a fatal error.
573 const DirectoryLookup *CurDir;
574 Optional<FileEntryRef> File = LookupFile(
575 SourceLocation(), PPOpts->PCHThroughHeader,
576 /*isAngled=*/false, /*FromDir=*/nullptr, /*FromFile=*/nullptr, CurDir,
577 /*SearchPath=*/nullptr, /*RelativePath=*/nullptr,
578 /*SuggestedModule=*/nullptr, /*IsMapped=*/nullptr,
579 /*IsFrameworkFound=*/nullptr);
580 if (!File) {
581 Diag(SourceLocation(), diag::err_pp_through_header_not_found)
582 << PPOpts->PCHThroughHeader;
583 return;
584 }
585 setPCHThroughHeaderFileID(
586 SourceMgr.createFileID(*File, SourceLocation(), SrcMgr::C_User));
587 }
588
589 // Skip tokens from the Predefines and if needed the main file.
590 if ((usingPCHWithThroughHeader() && SkippingUntilPCHThroughHeader) ||
591 (usingPCHWithPragmaHdrStop() && SkippingUntilPragmaHdrStop))
592 SkipTokensWhileUsingPCH();
593 }
594
setPCHThroughHeaderFileID(FileID FID)595 void Preprocessor::setPCHThroughHeaderFileID(FileID FID) {
596 assert(PCHThroughHeaderFileID.isInvalid() &&
597 "PCHThroughHeaderFileID already set!");
598 PCHThroughHeaderFileID = FID;
599 }
600
isPCHThroughHeader(const FileEntry * FE)601 bool Preprocessor::isPCHThroughHeader(const FileEntry *FE) {
602 assert(PCHThroughHeaderFileID.isValid() &&
603 "Invalid PCH through header FileID");
604 return FE == SourceMgr.getFileEntryForID(PCHThroughHeaderFileID);
605 }
606
creatingPCHWithThroughHeader()607 bool Preprocessor::creatingPCHWithThroughHeader() {
608 return TUKind == TU_Prefix && !PPOpts->PCHThroughHeader.empty() &&
609 PCHThroughHeaderFileID.isValid();
610 }
611
usingPCHWithThroughHeader()612 bool Preprocessor::usingPCHWithThroughHeader() {
613 return TUKind != TU_Prefix && !PPOpts->PCHThroughHeader.empty() &&
614 PCHThroughHeaderFileID.isValid();
615 }
616
creatingPCHWithPragmaHdrStop()617 bool Preprocessor::creatingPCHWithPragmaHdrStop() {
618 return TUKind == TU_Prefix && PPOpts->PCHWithHdrStop;
619 }
620
usingPCHWithPragmaHdrStop()621 bool Preprocessor::usingPCHWithPragmaHdrStop() {
622 return TUKind != TU_Prefix && PPOpts->PCHWithHdrStop;
623 }
624
625 /// Skip tokens until after the #include of the through header or
626 /// until after a #pragma hdrstop is seen. Tokens in the predefines file
627 /// and the main file may be skipped. If the end of the predefines file
628 /// is reached, skipping continues into the main file. If the end of the
629 /// main file is reached, it's a fatal error.
SkipTokensWhileUsingPCH()630 void Preprocessor::SkipTokensWhileUsingPCH() {
631 bool ReachedMainFileEOF = false;
632 bool UsingPCHThroughHeader = SkippingUntilPCHThroughHeader;
633 bool UsingPragmaHdrStop = SkippingUntilPragmaHdrStop;
634 Token Tok;
635 while (true) {
636 bool InPredefines =
637 (CurLexer && CurLexer->getFileID() == getPredefinesFileID());
638 switch (CurLexerKind) {
639 case CLK_Lexer:
640 CurLexer->Lex(Tok);
641 break;
642 case CLK_TokenLexer:
643 CurTokenLexer->Lex(Tok);
644 break;
645 case CLK_CachingLexer:
646 CachingLex(Tok);
647 break;
648 case CLK_LexAfterModuleImport:
649 LexAfterModuleImport(Tok);
650 break;
651 }
652 if (Tok.is(tok::eof) && !InPredefines) {
653 ReachedMainFileEOF = true;
654 break;
655 }
656 if (UsingPCHThroughHeader && !SkippingUntilPCHThroughHeader)
657 break;
658 if (UsingPragmaHdrStop && !SkippingUntilPragmaHdrStop)
659 break;
660 }
661 if (ReachedMainFileEOF) {
662 if (UsingPCHThroughHeader)
663 Diag(SourceLocation(), diag::err_pp_through_header_not_seen)
664 << PPOpts->PCHThroughHeader << 1;
665 else if (!PPOpts->PCHWithHdrStopCreate)
666 Diag(SourceLocation(), diag::err_pp_pragma_hdrstop_not_seen);
667 }
668 }
669
replayPreambleConditionalStack()670 void Preprocessor::replayPreambleConditionalStack() {
671 // Restore the conditional stack from the preamble, if there is one.
672 if (PreambleConditionalStack.isReplaying()) {
673 assert(CurPPLexer &&
674 "CurPPLexer is null when calling replayPreambleConditionalStack.");
675 CurPPLexer->setConditionalLevels(PreambleConditionalStack.getStack());
676 PreambleConditionalStack.doneReplaying();
677 if (PreambleConditionalStack.reachedEOFWhileSkipping())
678 SkipExcludedConditionalBlock(
679 PreambleConditionalStack.SkipInfo->HashTokenLoc,
680 PreambleConditionalStack.SkipInfo->IfTokenLoc,
681 PreambleConditionalStack.SkipInfo->FoundNonSkipPortion,
682 PreambleConditionalStack.SkipInfo->FoundElse,
683 PreambleConditionalStack.SkipInfo->ElseLoc);
684 }
685 }
686
EndSourceFile()687 void Preprocessor::EndSourceFile() {
688 // Notify the client that we reached the end of the source file.
689 if (Callbacks)
690 Callbacks->EndOfMainFile();
691 }
692
693 //===----------------------------------------------------------------------===//
694 // Lexer Event Handling.
695 //===----------------------------------------------------------------------===//
696
697 /// LookUpIdentifierInfo - Given a tok::raw_identifier token, look up the
698 /// identifier information for the token and install it into the token,
699 /// updating the token kind accordingly.
LookUpIdentifierInfo(Token & Identifier) const700 IdentifierInfo *Preprocessor::LookUpIdentifierInfo(Token &Identifier) const {
701 assert(!Identifier.getRawIdentifier().empty() && "No raw identifier data!");
702
703 // Look up this token, see if it is a macro, or if it is a language keyword.
704 IdentifierInfo *II;
705 if (!Identifier.needsCleaning() && !Identifier.hasUCN()) {
706 // No cleaning needed, just use the characters from the lexed buffer.
707 II = getIdentifierInfo(Identifier.getRawIdentifier());
708 } else {
709 // Cleaning needed, alloca a buffer, clean into it, then use the buffer.
710 SmallString<64> IdentifierBuffer;
711 StringRef CleanedStr = getSpelling(Identifier, IdentifierBuffer);
712
713 if (Identifier.hasUCN()) {
714 SmallString<64> UCNIdentifierBuffer;
715 expandUCNs(UCNIdentifierBuffer, CleanedStr);
716 II = getIdentifierInfo(UCNIdentifierBuffer);
717 } else {
718 II = getIdentifierInfo(CleanedStr);
719 }
720 }
721
722 // Update the token info (identifier info and appropriate token kind).
723 Identifier.setIdentifierInfo(II);
724 if (getLangOpts().MSVCCompat && II->isCPlusPlusOperatorKeyword() &&
725 getSourceManager().isInSystemHeader(Identifier.getLocation()))
726 Identifier.setKind(tok::identifier);
727 else
728 Identifier.setKind(II->getTokenID());
729
730 return II;
731 }
732
SetPoisonReason(IdentifierInfo * II,unsigned DiagID)733 void Preprocessor::SetPoisonReason(IdentifierInfo *II, unsigned DiagID) {
734 PoisonReasons[II] = DiagID;
735 }
736
PoisonSEHIdentifiers(bool Poison)737 void Preprocessor::PoisonSEHIdentifiers(bool Poison) {
738 assert(Ident__exception_code && Ident__exception_info);
739 assert(Ident___exception_code && Ident___exception_info);
740 Ident__exception_code->setIsPoisoned(Poison);
741 Ident___exception_code->setIsPoisoned(Poison);
742 Ident_GetExceptionCode->setIsPoisoned(Poison);
743 Ident__exception_info->setIsPoisoned(Poison);
744 Ident___exception_info->setIsPoisoned(Poison);
745 Ident_GetExceptionInfo->setIsPoisoned(Poison);
746 Ident__abnormal_termination->setIsPoisoned(Poison);
747 Ident___abnormal_termination->setIsPoisoned(Poison);
748 Ident_AbnormalTermination->setIsPoisoned(Poison);
749 }
750
HandlePoisonedIdentifier(Token & Identifier)751 void Preprocessor::HandlePoisonedIdentifier(Token & Identifier) {
752 assert(Identifier.getIdentifierInfo() &&
753 "Can't handle identifiers without identifier info!");
754 llvm::DenseMap<IdentifierInfo*,unsigned>::const_iterator it =
755 PoisonReasons.find(Identifier.getIdentifierInfo());
756 if(it == PoisonReasons.end())
757 Diag(Identifier, diag::err_pp_used_poisoned_id);
758 else
759 Diag(Identifier,it->second) << Identifier.getIdentifierInfo();
760 }
761
762 /// Returns a diagnostic message kind for reporting a future keyword as
763 /// appropriate for the identifier and specified language.
getFutureCompatDiagKind(const IdentifierInfo & II,const LangOptions & LangOpts)764 static diag::kind getFutureCompatDiagKind(const IdentifierInfo &II,
765 const LangOptions &LangOpts) {
766 assert(II.isFutureCompatKeyword() && "diagnostic should not be needed");
767
768 if (LangOpts.CPlusPlus)
769 return llvm::StringSwitch<diag::kind>(II.getName())
770 #define CXX11_KEYWORD(NAME, FLAGS) \
771 .Case(#NAME, diag::warn_cxx11_keyword)
772 #define CXX20_KEYWORD(NAME, FLAGS) \
773 .Case(#NAME, diag::warn_cxx20_keyword)
774 #include "clang/Basic/TokenKinds.def"
775 // char8_t is not modeled as a CXX20_KEYWORD because it's not
776 // unconditionally enabled in C++20 mode. (It can be disabled
777 // by -fno-char8_t.)
778 .Case("char8_t", diag::warn_cxx20_keyword)
779 ;
780
781 llvm_unreachable(
782 "Keyword not known to come from a newer Standard or proposed Standard");
783 }
784
updateOutOfDateIdentifier(IdentifierInfo & II) const785 void Preprocessor::updateOutOfDateIdentifier(IdentifierInfo &II) const {
786 assert(II.isOutOfDate() && "not out of date");
787 getExternalSource()->updateOutOfDateIdentifier(II);
788 }
789
790 /// HandleIdentifier - This callback is invoked when the lexer reads an
791 /// identifier. This callback looks up the identifier in the map and/or
792 /// potentially macro expands it or turns it into a named token (like 'for').
793 ///
794 /// Note that callers of this method are guarded by checking the
795 /// IdentifierInfo's 'isHandleIdentifierCase' bit. If this method changes, the
796 /// IdentifierInfo methods that compute these properties will need to change to
797 /// match.
HandleIdentifier(Token & Identifier)798 bool Preprocessor::HandleIdentifier(Token &Identifier) {
799 assert(Identifier.getIdentifierInfo() &&
800 "Can't handle identifiers without identifier info!");
801
802 IdentifierInfo &II = *Identifier.getIdentifierInfo();
803
804 // If the information about this identifier is out of date, update it from
805 // the external source.
806 // We have to treat __VA_ARGS__ in a special way, since it gets
807 // serialized with isPoisoned = true, but our preprocessor may have
808 // unpoisoned it if we're defining a C99 macro.
809 if (II.isOutOfDate()) {
810 bool CurrentIsPoisoned = false;
811 const bool IsSpecialVariadicMacro =
812 &II == Ident__VA_ARGS__ || &II == Ident__VA_OPT__;
813 if (IsSpecialVariadicMacro)
814 CurrentIsPoisoned = II.isPoisoned();
815
816 updateOutOfDateIdentifier(II);
817 Identifier.setKind(II.getTokenID());
818
819 if (IsSpecialVariadicMacro)
820 II.setIsPoisoned(CurrentIsPoisoned);
821 }
822
823 // If this identifier was poisoned, and if it was not produced from a macro
824 // expansion, emit an error.
825 if (II.isPoisoned() && CurPPLexer) {
826 HandlePoisonedIdentifier(Identifier);
827 }
828
829 // If this is a macro to be expanded, do it.
830 if (MacroDefinition MD = getMacroDefinition(&II)) {
831 auto *MI = MD.getMacroInfo();
832 assert(MI && "macro definition with no macro info?");
833 if (!DisableMacroExpansion) {
834 if (!Identifier.isExpandDisabled() && MI->isEnabled()) {
835 // C99 6.10.3p10: If the preprocessing token immediately after the
836 // macro name isn't a '(', this macro should not be expanded.
837 if (!MI->isFunctionLike() || isNextPPTokenLParen())
838 return HandleMacroExpandedIdentifier(Identifier, MD);
839 } else {
840 // C99 6.10.3.4p2 says that a disabled macro may never again be
841 // expanded, even if it's in a context where it could be expanded in the
842 // future.
843 Identifier.setFlag(Token::DisableExpand);
844 if (MI->isObjectLike() || isNextPPTokenLParen())
845 Diag(Identifier, diag::pp_disabled_macro_expansion);
846 }
847 }
848 }
849
850 // If this identifier is a keyword in a newer Standard or proposed Standard,
851 // produce a warning. Don't warn if we're not considering macro expansion,
852 // since this identifier might be the name of a macro.
853 // FIXME: This warning is disabled in cases where it shouldn't be, like
854 // "#define constexpr constexpr", "int constexpr;"
855 if (II.isFutureCompatKeyword() && !DisableMacroExpansion) {
856 Diag(Identifier, getFutureCompatDiagKind(II, getLangOpts()))
857 << II.getName();
858 // Don't diagnose this keyword again in this translation unit.
859 II.setIsFutureCompatKeyword(false);
860 }
861
862 // If this is an extension token, diagnose its use.
863 // We avoid diagnosing tokens that originate from macro definitions.
864 // FIXME: This warning is disabled in cases where it shouldn't be,
865 // like "#define TY typeof", "TY(1) x".
866 if (II.isExtensionToken() && !DisableMacroExpansion)
867 Diag(Identifier, diag::ext_token_used);
868
869 // If this is the 'import' contextual keyword following an '@', note
870 // that the next token indicates a module name.
871 //
872 // Note that we do not treat 'import' as a contextual
873 // keyword when we're in a caching lexer, because caching lexers only get
874 // used in contexts where import declarations are disallowed.
875 //
876 // Likewise if this is the C++ Modules TS import keyword.
877 if (((LastTokenWasAt && II.isModulesImport()) ||
878 Identifier.is(tok::kw_import)) &&
879 !InMacroArgs && !DisableMacroExpansion &&
880 (getLangOpts().Modules || getLangOpts().DebuggerSupport) &&
881 CurLexerKind != CLK_CachingLexer) {
882 ModuleImportLoc = Identifier.getLocation();
883 ModuleImportPath.clear();
884 ModuleImportExpectsIdentifier = true;
885 CurLexerKind = CLK_LexAfterModuleImport;
886 }
887 return true;
888 }
889
Lex(Token & Result)890 void Preprocessor::Lex(Token &Result) {
891 ++LexLevel;
892
893 // We loop here until a lex function returns a token; this avoids recursion.
894 bool ReturnedToken;
895 do {
896 switch (CurLexerKind) {
897 case CLK_Lexer:
898 ReturnedToken = CurLexer->Lex(Result);
899 break;
900 case CLK_TokenLexer:
901 ReturnedToken = CurTokenLexer->Lex(Result);
902 break;
903 case CLK_CachingLexer:
904 CachingLex(Result);
905 ReturnedToken = true;
906 break;
907 case CLK_LexAfterModuleImport:
908 ReturnedToken = LexAfterModuleImport(Result);
909 break;
910 }
911 } while (!ReturnedToken);
912
913 if (Result.is(tok::unknown) && TheModuleLoader.HadFatalFailure)
914 return;
915
916 if (Result.is(tok::code_completion) && Result.getIdentifierInfo()) {
917 // Remember the identifier before code completion token.
918 setCodeCompletionIdentifierInfo(Result.getIdentifierInfo());
919 setCodeCompletionTokenRange(Result.getLocation(), Result.getEndLoc());
920 // Set IdenfitierInfo to null to avoid confusing code that handles both
921 // identifiers and completion tokens.
922 Result.setIdentifierInfo(nullptr);
923 }
924
925 // Update ImportSeqState to track our position within a C++20 import-seq
926 // if this token is being produced as a result of phase 4 of translation.
927 if (getLangOpts().CPlusPlusModules && LexLevel == 1 &&
928 !Result.getFlag(Token::IsReinjected)) {
929 switch (Result.getKind()) {
930 case tok::l_paren: case tok::l_square: case tok::l_brace:
931 ImportSeqState.handleOpenBracket();
932 break;
933 case tok::r_paren: case tok::r_square:
934 ImportSeqState.handleCloseBracket();
935 break;
936 case tok::r_brace:
937 ImportSeqState.handleCloseBrace();
938 break;
939 case tok::semi:
940 ImportSeqState.handleSemi();
941 break;
942 case tok::header_name:
943 case tok::annot_header_unit:
944 ImportSeqState.handleHeaderName();
945 break;
946 case tok::kw_export:
947 ImportSeqState.handleExport();
948 break;
949 case tok::identifier:
950 if (Result.getIdentifierInfo()->isModulesImport()) {
951 ImportSeqState.handleImport();
952 if (ImportSeqState.afterImportSeq()) {
953 ModuleImportLoc = Result.getLocation();
954 ModuleImportPath.clear();
955 ModuleImportExpectsIdentifier = true;
956 CurLexerKind = CLK_LexAfterModuleImport;
957 }
958 break;
959 }
960 LLVM_FALLTHROUGH;
961 default:
962 ImportSeqState.handleMisc();
963 break;
964 }
965 }
966
967 LastTokenWasAt = Result.is(tok::at);
968 --LexLevel;
969
970 if ((LexLevel == 0 || PreprocessToken) &&
971 !Result.getFlag(Token::IsReinjected)) {
972 if (LexLevel == 0)
973 ++TokenCount;
974 if (OnToken)
975 OnToken(Result);
976 }
977 }
978
979 /// Lex a header-name token (including one formed from header-name-tokens if
980 /// \p AllowConcatenation is \c true).
981 ///
982 /// \param FilenameTok Filled in with the next token. On success, this will
983 /// be either a header_name token. On failure, it will be whatever other
984 /// token was found instead.
985 /// \param AllowMacroExpansion If \c true, allow the header name to be formed
986 /// by macro expansion (concatenating tokens as necessary if the first
987 /// token is a '<').
988 /// \return \c true if we reached EOD or EOF while looking for a > token in
989 /// a concatenated header name and diagnosed it. \c false otherwise.
LexHeaderName(Token & FilenameTok,bool AllowMacroExpansion)990 bool Preprocessor::LexHeaderName(Token &FilenameTok, bool AllowMacroExpansion) {
991 // Lex using header-name tokenization rules if tokens are being lexed from
992 // a file. Just grab a token normally if we're in a macro expansion.
993 if (CurPPLexer)
994 CurPPLexer->LexIncludeFilename(FilenameTok);
995 else
996 Lex(FilenameTok);
997
998 // This could be a <foo/bar.h> file coming from a macro expansion. In this
999 // case, glue the tokens together into an angle_string_literal token.
1000 SmallString<128> FilenameBuffer;
1001 if (FilenameTok.is(tok::less) && AllowMacroExpansion) {
1002 bool StartOfLine = FilenameTok.isAtStartOfLine();
1003 bool LeadingSpace = FilenameTok.hasLeadingSpace();
1004 bool LeadingEmptyMacro = FilenameTok.hasLeadingEmptyMacro();
1005
1006 SourceLocation Start = FilenameTok.getLocation();
1007 SourceLocation End;
1008 FilenameBuffer.push_back('<');
1009
1010 // Consume tokens until we find a '>'.
1011 // FIXME: A header-name could be formed starting or ending with an
1012 // alternative token. It's not clear whether that's ill-formed in all
1013 // cases.
1014 while (FilenameTok.isNot(tok::greater)) {
1015 Lex(FilenameTok);
1016 if (FilenameTok.isOneOf(tok::eod, tok::eof)) {
1017 Diag(FilenameTok.getLocation(), diag::err_expected) << tok::greater;
1018 Diag(Start, diag::note_matching) << tok::less;
1019 return true;
1020 }
1021
1022 End = FilenameTok.getLocation();
1023
1024 // FIXME: Provide code completion for #includes.
1025 if (FilenameTok.is(tok::code_completion)) {
1026 setCodeCompletionReached();
1027 Lex(FilenameTok);
1028 continue;
1029 }
1030
1031 // Append the spelling of this token to the buffer. If there was a space
1032 // before it, add it now.
1033 if (FilenameTok.hasLeadingSpace())
1034 FilenameBuffer.push_back(' ');
1035
1036 // Get the spelling of the token, directly into FilenameBuffer if
1037 // possible.
1038 size_t PreAppendSize = FilenameBuffer.size();
1039 FilenameBuffer.resize(PreAppendSize + FilenameTok.getLength());
1040
1041 const char *BufPtr = &FilenameBuffer[PreAppendSize];
1042 unsigned ActualLen = getSpelling(FilenameTok, BufPtr);
1043
1044 // If the token was spelled somewhere else, copy it into FilenameBuffer.
1045 if (BufPtr != &FilenameBuffer[PreAppendSize])
1046 memcpy(&FilenameBuffer[PreAppendSize], BufPtr, ActualLen);
1047
1048 // Resize FilenameBuffer to the correct size.
1049 if (FilenameTok.getLength() != ActualLen)
1050 FilenameBuffer.resize(PreAppendSize + ActualLen);
1051 }
1052
1053 FilenameTok.startToken();
1054 FilenameTok.setKind(tok::header_name);
1055 FilenameTok.setFlagValue(Token::StartOfLine, StartOfLine);
1056 FilenameTok.setFlagValue(Token::LeadingSpace, LeadingSpace);
1057 FilenameTok.setFlagValue(Token::LeadingEmptyMacro, LeadingEmptyMacro);
1058 CreateString(FilenameBuffer, FilenameTok, Start, End);
1059 } else if (FilenameTok.is(tok::string_literal) && AllowMacroExpansion) {
1060 // Convert a string-literal token of the form " h-char-sequence "
1061 // (produced by macro expansion) into a header-name token.
1062 //
1063 // The rules for header-names don't quite match the rules for
1064 // string-literals, but all the places where they differ result in
1065 // undefined behavior, so we can and do treat them the same.
1066 //
1067 // A string-literal with a prefix or suffix is not translated into a
1068 // header-name. This could theoretically be observable via the C++20
1069 // context-sensitive header-name formation rules.
1070 StringRef Str = getSpelling(FilenameTok, FilenameBuffer);
1071 if (Str.size() >= 2 && Str.front() == '"' && Str.back() == '"')
1072 FilenameTok.setKind(tok::header_name);
1073 }
1074
1075 return false;
1076 }
1077
1078 /// Collect the tokens of a C++20 pp-import-suffix.
CollectPpImportSuffix(SmallVectorImpl<Token> & Toks)1079 void Preprocessor::CollectPpImportSuffix(SmallVectorImpl<Token> &Toks) {
1080 // FIXME: For error recovery, consider recognizing attribute syntax here
1081 // and terminating / diagnosing a missing semicolon if we find anything
1082 // else? (Can we leave that to the parser?)
1083 unsigned BracketDepth = 0;
1084 while (true) {
1085 Toks.emplace_back();
1086 Lex(Toks.back());
1087
1088 switch (Toks.back().getKind()) {
1089 case tok::l_paren: case tok::l_square: case tok::l_brace:
1090 ++BracketDepth;
1091 break;
1092
1093 case tok::r_paren: case tok::r_square: case tok::r_brace:
1094 if (BracketDepth == 0)
1095 return;
1096 --BracketDepth;
1097 break;
1098
1099 case tok::semi:
1100 if (BracketDepth == 0)
1101 return;
1102 break;
1103
1104 case tok::eof:
1105 return;
1106
1107 default:
1108 break;
1109 }
1110 }
1111 }
1112
1113
1114 /// Lex a token following the 'import' contextual keyword.
1115 ///
1116 /// pp-import: [C++20]
1117 /// import header-name pp-import-suffix[opt] ;
1118 /// import header-name-tokens pp-import-suffix[opt] ;
1119 /// [ObjC] @ import module-name ;
1120 /// [Clang] import module-name ;
1121 ///
1122 /// header-name-tokens:
1123 /// string-literal
1124 /// < [any sequence of preprocessing-tokens other than >] >
1125 ///
1126 /// module-name:
1127 /// module-name-qualifier[opt] identifier
1128 ///
1129 /// module-name-qualifier
1130 /// module-name-qualifier[opt] identifier .
1131 ///
1132 /// We respond to a pp-import by importing macros from the named module.
LexAfterModuleImport(Token & Result)1133 bool Preprocessor::LexAfterModuleImport(Token &Result) {
1134 // Figure out what kind of lexer we actually have.
1135 recomputeCurLexerKind();
1136
1137 // Lex the next token. The header-name lexing rules are used at the start of
1138 // a pp-import.
1139 //
1140 // For now, we only support header-name imports in C++20 mode.
1141 // FIXME: Should we allow this in all language modes that support an import
1142 // declaration as an extension?
1143 if (ModuleImportPath.empty() && getLangOpts().CPlusPlusModules) {
1144 if (LexHeaderName(Result))
1145 return true;
1146 } else {
1147 Lex(Result);
1148 }
1149
1150 // Allocate a holding buffer for a sequence of tokens and introduce it into
1151 // the token stream.
1152 auto EnterTokens = [this](ArrayRef<Token> Toks) {
1153 auto ToksCopy = std::make_unique<Token[]>(Toks.size());
1154 std::copy(Toks.begin(), Toks.end(), ToksCopy.get());
1155 EnterTokenStream(std::move(ToksCopy), Toks.size(),
1156 /*DisableMacroExpansion*/ true, /*IsReinject*/ false);
1157 };
1158
1159 // Check for a header-name.
1160 SmallVector<Token, 32> Suffix;
1161 if (Result.is(tok::header_name)) {
1162 // Enter the header-name token into the token stream; a Lex action cannot
1163 // both return a token and cache tokens (doing so would corrupt the token
1164 // cache if the call to Lex comes from CachingLex / PeekAhead).
1165 Suffix.push_back(Result);
1166
1167 // Consume the pp-import-suffix and expand any macros in it now. We'll add
1168 // it back into the token stream later.
1169 CollectPpImportSuffix(Suffix);
1170 if (Suffix.back().isNot(tok::semi)) {
1171 // This is not a pp-import after all.
1172 EnterTokens(Suffix);
1173 return false;
1174 }
1175
1176 // C++2a [cpp.module]p1:
1177 // The ';' preprocessing-token terminating a pp-import shall not have
1178 // been produced by macro replacement.
1179 SourceLocation SemiLoc = Suffix.back().getLocation();
1180 if (SemiLoc.isMacroID())
1181 Diag(SemiLoc, diag::err_header_import_semi_in_macro);
1182
1183 // Reconstitute the import token.
1184 Token ImportTok;
1185 ImportTok.startToken();
1186 ImportTok.setKind(tok::kw_import);
1187 ImportTok.setLocation(ModuleImportLoc);
1188 ImportTok.setIdentifierInfo(getIdentifierInfo("import"));
1189 ImportTok.setLength(6);
1190
1191 auto Action = HandleHeaderIncludeOrImport(
1192 /*HashLoc*/ SourceLocation(), ImportTok, Suffix.front(), SemiLoc);
1193 switch (Action.Kind) {
1194 case ImportAction::None:
1195 break;
1196
1197 case ImportAction::ModuleBegin:
1198 // Let the parser know we're textually entering the module.
1199 Suffix.emplace_back();
1200 Suffix.back().startToken();
1201 Suffix.back().setKind(tok::annot_module_begin);
1202 Suffix.back().setLocation(SemiLoc);
1203 Suffix.back().setAnnotationEndLoc(SemiLoc);
1204 Suffix.back().setAnnotationValue(Action.ModuleForHeader);
1205 LLVM_FALLTHROUGH;
1206
1207 case ImportAction::ModuleImport:
1208 case ImportAction::SkippedModuleImport:
1209 // We chose to import (or textually enter) the file. Convert the
1210 // header-name token into a header unit annotation token.
1211 Suffix[0].setKind(tok::annot_header_unit);
1212 Suffix[0].setAnnotationEndLoc(Suffix[0].getLocation());
1213 Suffix[0].setAnnotationValue(Action.ModuleForHeader);
1214 // FIXME: Call the moduleImport callback?
1215 break;
1216 case ImportAction::Failure:
1217 assert(TheModuleLoader.HadFatalFailure &&
1218 "This should be an early exit only to a fatal error");
1219 Result.setKind(tok::eof);
1220 CurLexer->cutOffLexing();
1221 EnterTokens(Suffix);
1222 return true;
1223 }
1224
1225 EnterTokens(Suffix);
1226 return false;
1227 }
1228
1229 // The token sequence
1230 //
1231 // import identifier (. identifier)*
1232 //
1233 // indicates a module import directive. We already saw the 'import'
1234 // contextual keyword, so now we're looking for the identifiers.
1235 if (ModuleImportExpectsIdentifier && Result.getKind() == tok::identifier) {
1236 // We expected to see an identifier here, and we did; continue handling
1237 // identifiers.
1238 ModuleImportPath.push_back(std::make_pair(Result.getIdentifierInfo(),
1239 Result.getLocation()));
1240 ModuleImportExpectsIdentifier = false;
1241 CurLexerKind = CLK_LexAfterModuleImport;
1242 return true;
1243 }
1244
1245 // If we're expecting a '.' or a ';', and we got a '.', then wait until we
1246 // see the next identifier. (We can also see a '[[' that begins an
1247 // attribute-specifier-seq here under the C++ Modules TS.)
1248 if (!ModuleImportExpectsIdentifier && Result.getKind() == tok::period) {
1249 ModuleImportExpectsIdentifier = true;
1250 CurLexerKind = CLK_LexAfterModuleImport;
1251 return true;
1252 }
1253
1254 // If we didn't recognize a module name at all, this is not a (valid) import.
1255 if (ModuleImportPath.empty() || Result.is(tok::eof))
1256 return true;
1257
1258 // Consume the pp-import-suffix and expand any macros in it now, if we're not
1259 // at the semicolon already.
1260 SourceLocation SemiLoc = Result.getLocation();
1261 if (Result.isNot(tok::semi)) {
1262 Suffix.push_back(Result);
1263 CollectPpImportSuffix(Suffix);
1264 if (Suffix.back().isNot(tok::semi)) {
1265 // This is not an import after all.
1266 EnterTokens(Suffix);
1267 return false;
1268 }
1269 SemiLoc = Suffix.back().getLocation();
1270 }
1271
1272 // Under the Modules TS, the dot is just part of the module name, and not
1273 // a real hierarchy separator. Flatten such module names now.
1274 //
1275 // FIXME: Is this the right level to be performing this transformation?
1276 std::string FlatModuleName;
1277 if (getLangOpts().ModulesTS || getLangOpts().CPlusPlusModules) {
1278 for (auto &Piece : ModuleImportPath) {
1279 if (!FlatModuleName.empty())
1280 FlatModuleName += ".";
1281 FlatModuleName += Piece.first->getName();
1282 }
1283 SourceLocation FirstPathLoc = ModuleImportPath[0].second;
1284 ModuleImportPath.clear();
1285 ModuleImportPath.push_back(
1286 std::make_pair(getIdentifierInfo(FlatModuleName), FirstPathLoc));
1287 }
1288
1289 Module *Imported = nullptr;
1290 if (getLangOpts().Modules) {
1291 Imported = TheModuleLoader.loadModule(ModuleImportLoc,
1292 ModuleImportPath,
1293 Module::Hidden,
1294 /*IsInclusionDirective=*/false);
1295 if (Imported)
1296 makeModuleVisible(Imported, SemiLoc);
1297 }
1298 if (Callbacks)
1299 Callbacks->moduleImport(ModuleImportLoc, ModuleImportPath, Imported);
1300
1301 if (!Suffix.empty()) {
1302 EnterTokens(Suffix);
1303 return false;
1304 }
1305 return true;
1306 }
1307
makeModuleVisible(Module * M,SourceLocation Loc)1308 void Preprocessor::makeModuleVisible(Module *M, SourceLocation Loc) {
1309 CurSubmoduleState->VisibleModules.setVisible(
1310 M, Loc, [](Module *) {},
1311 [&](ArrayRef<Module *> Path, Module *Conflict, StringRef Message) {
1312 // FIXME: Include the path in the diagnostic.
1313 // FIXME: Include the import location for the conflicting module.
1314 Diag(ModuleImportLoc, diag::warn_module_conflict)
1315 << Path[0]->getFullModuleName()
1316 << Conflict->getFullModuleName()
1317 << Message;
1318 });
1319
1320 // Add this module to the imports list of the currently-built submodule.
1321 if (!BuildingSubmoduleStack.empty() && M != BuildingSubmoduleStack.back().M)
1322 BuildingSubmoduleStack.back().M->Imports.insert(M);
1323 }
1324
FinishLexStringLiteral(Token & Result,std::string & String,const char * DiagnosticTag,bool AllowMacroExpansion)1325 bool Preprocessor::FinishLexStringLiteral(Token &Result, std::string &String,
1326 const char *DiagnosticTag,
1327 bool AllowMacroExpansion) {
1328 // We need at least one string literal.
1329 if (Result.isNot(tok::string_literal)) {
1330 Diag(Result, diag::err_expected_string_literal)
1331 << /*Source='in...'*/0 << DiagnosticTag;
1332 return false;
1333 }
1334
1335 // Lex string literal tokens, optionally with macro expansion.
1336 SmallVector<Token, 4> StrToks;
1337 do {
1338 StrToks.push_back(Result);
1339
1340 if (Result.hasUDSuffix())
1341 Diag(Result, diag::err_invalid_string_udl);
1342
1343 if (AllowMacroExpansion)
1344 Lex(Result);
1345 else
1346 LexUnexpandedToken(Result);
1347 } while (Result.is(tok::string_literal));
1348
1349 // Concatenate and parse the strings.
1350 StringLiteralParser Literal(StrToks, *this);
1351 assert(Literal.isAscii() && "Didn't allow wide strings in");
1352
1353 if (Literal.hadError)
1354 return false;
1355
1356 if (Literal.Pascal) {
1357 Diag(StrToks[0].getLocation(), diag::err_expected_string_literal)
1358 << /*Source='in...'*/0 << DiagnosticTag;
1359 return false;
1360 }
1361
1362 String = std::string(Literal.GetString());
1363 return true;
1364 }
1365
parseSimpleIntegerLiteral(Token & Tok,uint64_t & Value)1366 bool Preprocessor::parseSimpleIntegerLiteral(Token &Tok, uint64_t &Value) {
1367 assert(Tok.is(tok::numeric_constant));
1368 SmallString<8> IntegerBuffer;
1369 bool NumberInvalid = false;
1370 StringRef Spelling = getSpelling(Tok, IntegerBuffer, &NumberInvalid);
1371 if (NumberInvalid)
1372 return false;
1373 NumericLiteralParser Literal(Spelling, Tok.getLocation(), getSourceManager(),
1374 getLangOpts(), getTargetInfo(),
1375 getDiagnostics());
1376 if (Literal.hadError || !Literal.isIntegerLiteral() || Literal.hasUDSuffix())
1377 return false;
1378 llvm::APInt APVal(64, 0);
1379 if (Literal.GetIntegerValue(APVal))
1380 return false;
1381 Lex(Tok);
1382 Value = APVal.getLimitedValue();
1383 return true;
1384 }
1385
addCommentHandler(CommentHandler * Handler)1386 void Preprocessor::addCommentHandler(CommentHandler *Handler) {
1387 assert(Handler && "NULL comment handler");
1388 assert(llvm::find(CommentHandlers, Handler) == CommentHandlers.end() &&
1389 "Comment handler already registered");
1390 CommentHandlers.push_back(Handler);
1391 }
1392
removeCommentHandler(CommentHandler * Handler)1393 void Preprocessor::removeCommentHandler(CommentHandler *Handler) {
1394 std::vector<CommentHandler *>::iterator Pos =
1395 llvm::find(CommentHandlers, Handler);
1396 assert(Pos != CommentHandlers.end() && "Comment handler not registered");
1397 CommentHandlers.erase(Pos);
1398 }
1399
HandleComment(Token & result,SourceRange Comment)1400 bool Preprocessor::HandleComment(Token &result, SourceRange Comment) {
1401 bool AnyPendingTokens = false;
1402 for (std::vector<CommentHandler *>::iterator H = CommentHandlers.begin(),
1403 HEnd = CommentHandlers.end();
1404 H != HEnd; ++H) {
1405 if ((*H)->HandleComment(*this, Comment))
1406 AnyPendingTokens = true;
1407 }
1408 if (!AnyPendingTokens || getCommentRetentionState())
1409 return false;
1410 Lex(result);
1411 return true;
1412 }
1413
1414 ModuleLoader::~ModuleLoader() = default;
1415
1416 CommentHandler::~CommentHandler() = default;
1417
1418 EmptylineHandler::~EmptylineHandler() = default;
1419
1420 CodeCompletionHandler::~CodeCompletionHandler() = default;
1421
createPreprocessingRecord()1422 void Preprocessor::createPreprocessingRecord() {
1423 if (Record)
1424 return;
1425
1426 Record = new PreprocessingRecord(getSourceManager());
1427 addPPCallbacks(std::unique_ptr<PPCallbacks>(Record));
1428 }
1429