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1 //===--- MacroExpansion.cpp - Top level Macro Expansion -------------------===//
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 implements the top level handling of macro expansion for the
11 // preprocessor.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #include "clang/Lex/Preprocessor.h"
16 #include "clang/Basic/Attributes.h"
17 #include "clang/Basic/FileManager.h"
18 #include "clang/Basic/SourceManager.h"
19 #include "clang/Basic/TargetInfo.h"
20 #include "clang/Lex/CodeCompletionHandler.h"
21 #include "clang/Lex/ExternalPreprocessorSource.h"
22 #include "clang/Lex/LexDiagnostic.h"
23 #include "clang/Lex/MacroArgs.h"
24 #include "clang/Lex/MacroInfo.h"
25 #include "llvm/ADT/STLExtras.h"
26 #include "llvm/ADT/SmallString.h"
27 #include "llvm/ADT/StringSwitch.h"
28 #include "llvm/Config/llvm-config.h"
29 #include "llvm/Support/ErrorHandling.h"
30 #include "llvm/Support/Format.h"
31 #include "llvm/Support/raw_ostream.h"
32 #include <cstdio>
33 #include <ctime>
34 using namespace clang;
35 
36 MacroDirective *
getLocalMacroDirectiveHistory(const IdentifierInfo * II) const37 Preprocessor::getLocalMacroDirectiveHistory(const IdentifierInfo *II) const {
38   if (!II->hadMacroDefinition())
39     return nullptr;
40   auto Pos = CurSubmoduleState->Macros.find(II);
41   return Pos == CurSubmoduleState->Macros.end() ? nullptr
42                                                 : Pos->second.getLatest();
43 }
44 
appendMacroDirective(IdentifierInfo * II,MacroDirective * MD)45 void Preprocessor::appendMacroDirective(IdentifierInfo *II, MacroDirective *MD){
46   assert(MD && "MacroDirective should be non-zero!");
47   assert(!MD->getPrevious() && "Already attached to a MacroDirective history.");
48 
49   MacroState &StoredMD = CurSubmoduleState->Macros[II];
50   auto *OldMD = StoredMD.getLatest();
51   MD->setPrevious(OldMD);
52   StoredMD.setLatest(MD);
53   StoredMD.overrideActiveModuleMacros(*this, II);
54 
55   if (needModuleMacros()) {
56     // Track that we created a new macro directive, so we know we should
57     // consider building a ModuleMacro for it when we get to the end of
58     // the module.
59     PendingModuleMacroNames.push_back(II);
60   }
61 
62   // Set up the identifier as having associated macro history.
63   II->setHasMacroDefinition(true);
64   if (!MD->isDefined() && LeafModuleMacros.find(II) == LeafModuleMacros.end())
65     II->setHasMacroDefinition(false);
66   if (II->isFromAST())
67     II->setChangedSinceDeserialization();
68 }
69 
setLoadedMacroDirective(IdentifierInfo * II,MacroDirective * MD)70 void Preprocessor::setLoadedMacroDirective(IdentifierInfo *II,
71                                            MacroDirective *MD) {
72   assert(II && MD);
73   MacroState &StoredMD = CurSubmoduleState->Macros[II];
74   assert(!StoredMD.getLatest() &&
75          "the macro history was modified before initializing it from a pch");
76   StoredMD = MD;
77   // Setup the identifier as having associated macro history.
78   II->setHasMacroDefinition(true);
79   if (!MD->isDefined() && LeafModuleMacros.find(II) == LeafModuleMacros.end())
80     II->setHasMacroDefinition(false);
81 }
82 
addModuleMacro(Module * Mod,IdentifierInfo * II,MacroInfo * Macro,ArrayRef<ModuleMacro * > Overrides,bool & New)83 ModuleMacro *Preprocessor::addModuleMacro(Module *Mod, IdentifierInfo *II,
84                                           MacroInfo *Macro,
85                                           ArrayRef<ModuleMacro *> Overrides,
86                                           bool &New) {
87   llvm::FoldingSetNodeID ID;
88   ModuleMacro::Profile(ID, Mod, II);
89 
90   void *InsertPos;
91   if (auto *MM = ModuleMacros.FindNodeOrInsertPos(ID, InsertPos)) {
92     New = false;
93     return MM;
94   }
95 
96   auto *MM = ModuleMacro::create(*this, Mod, II, Macro, Overrides);
97   ModuleMacros.InsertNode(MM, InsertPos);
98 
99   // Each overridden macro is now overridden by one more macro.
100   bool HidAny = false;
101   for (auto *O : Overrides) {
102     HidAny |= (O->NumOverriddenBy == 0);
103     ++O->NumOverriddenBy;
104   }
105 
106   // If we were the first overrider for any macro, it's no longer a leaf.
107   auto &LeafMacros = LeafModuleMacros[II];
108   if (HidAny) {
109     LeafMacros.erase(std::remove_if(LeafMacros.begin(), LeafMacros.end(),
110                                     [](ModuleMacro *MM) {
111                                       return MM->NumOverriddenBy != 0;
112                                     }),
113                      LeafMacros.end());
114   }
115 
116   // The new macro is always a leaf macro.
117   LeafMacros.push_back(MM);
118   // The identifier now has defined macros (that may or may not be visible).
119   II->setHasMacroDefinition(true);
120 
121   New = true;
122   return MM;
123 }
124 
getModuleMacro(Module * Mod,IdentifierInfo * II)125 ModuleMacro *Preprocessor::getModuleMacro(Module *Mod, IdentifierInfo *II) {
126   llvm::FoldingSetNodeID ID;
127   ModuleMacro::Profile(ID, Mod, II);
128 
129   void *InsertPos;
130   return ModuleMacros.FindNodeOrInsertPos(ID, InsertPos);
131 }
132 
updateModuleMacroInfo(const IdentifierInfo * II,ModuleMacroInfo & Info)133 void Preprocessor::updateModuleMacroInfo(const IdentifierInfo *II,
134                                          ModuleMacroInfo &Info) {
135   assert(Info.ActiveModuleMacrosGeneration !=
136              CurSubmoduleState->VisibleModules.getGeneration() &&
137          "don't need to update this macro name info");
138   Info.ActiveModuleMacrosGeneration =
139       CurSubmoduleState->VisibleModules.getGeneration();
140 
141   auto Leaf = LeafModuleMacros.find(II);
142   if (Leaf == LeafModuleMacros.end()) {
143     // No imported macros at all: nothing to do.
144     return;
145   }
146 
147   Info.ActiveModuleMacros.clear();
148 
149   // Every macro that's locally overridden is overridden by a visible macro.
150   llvm::DenseMap<ModuleMacro *, int> NumHiddenOverrides;
151   for (auto *O : Info.OverriddenMacros)
152     NumHiddenOverrides[O] = -1;
153 
154   // Collect all macros that are not overridden by a visible macro.
155   llvm::SmallVector<ModuleMacro *, 16> Worklist;
156   for (auto *LeafMM : Leaf->second) {
157     assert(LeafMM->getNumOverridingMacros() == 0 && "leaf macro overridden");
158     if (NumHiddenOverrides.lookup(LeafMM) == 0)
159       Worklist.push_back(LeafMM);
160   }
161   while (!Worklist.empty()) {
162     auto *MM = Worklist.pop_back_val();
163     if (CurSubmoduleState->VisibleModules.isVisible(MM->getOwningModule())) {
164       // We only care about collecting definitions; undefinitions only act
165       // to override other definitions.
166       if (MM->getMacroInfo())
167         Info.ActiveModuleMacros.push_back(MM);
168     } else {
169       for (auto *O : MM->overrides())
170         if ((unsigned)++NumHiddenOverrides[O] == O->getNumOverridingMacros())
171           Worklist.push_back(O);
172     }
173   }
174   // Our reverse postorder walk found the macros in reverse order.
175   std::reverse(Info.ActiveModuleMacros.begin(), Info.ActiveModuleMacros.end());
176 
177   // Determine whether the macro name is ambiguous.
178   MacroInfo *MI = nullptr;
179   bool IsSystemMacro = true;
180   bool IsAmbiguous = false;
181   if (auto *MD = Info.MD) {
182     while (MD && isa<VisibilityMacroDirective>(MD))
183       MD = MD->getPrevious();
184     if (auto *DMD = dyn_cast_or_null<DefMacroDirective>(MD)) {
185       MI = DMD->getInfo();
186       IsSystemMacro &= SourceMgr.isInSystemHeader(DMD->getLocation());
187     }
188   }
189   for (auto *Active : Info.ActiveModuleMacros) {
190     auto *NewMI = Active->getMacroInfo();
191 
192     // Before marking the macro as ambiguous, check if this is a case where
193     // both macros are in system headers. If so, we trust that the system
194     // did not get it wrong. This also handles cases where Clang's own
195     // headers have a different spelling of certain system macros:
196     //   #define LONG_MAX __LONG_MAX__ (clang's limits.h)
197     //   #define LONG_MAX 0x7fffffffffffffffL (system's limits.h)
198     //
199     // FIXME: Remove the defined-in-system-headers check. clang's limits.h
200     // overrides the system limits.h's macros, so there's no conflict here.
201     if (MI && NewMI != MI &&
202         !MI->isIdenticalTo(*NewMI, *this, /*Syntactically=*/true))
203       IsAmbiguous = true;
204     IsSystemMacro &= Active->getOwningModule()->IsSystem ||
205                      SourceMgr.isInSystemHeader(NewMI->getDefinitionLoc());
206     MI = NewMI;
207   }
208   Info.IsAmbiguous = IsAmbiguous && !IsSystemMacro;
209 }
210 
dumpMacroInfo(const IdentifierInfo * II)211 void Preprocessor::dumpMacroInfo(const IdentifierInfo *II) {
212   ArrayRef<ModuleMacro*> Leaf;
213   auto LeafIt = LeafModuleMacros.find(II);
214   if (LeafIt != LeafModuleMacros.end())
215     Leaf = LeafIt->second;
216   const MacroState *State = nullptr;
217   auto Pos = CurSubmoduleState->Macros.find(II);
218   if (Pos != CurSubmoduleState->Macros.end())
219     State = &Pos->second;
220 
221   llvm::errs() << "MacroState " << State << " " << II->getNameStart();
222   if (State && State->isAmbiguous(*this, II))
223     llvm::errs() << " ambiguous";
224   if (State && !State->getOverriddenMacros().empty()) {
225     llvm::errs() << " overrides";
226     for (auto *O : State->getOverriddenMacros())
227       llvm::errs() << " " << O->getOwningModule()->getFullModuleName();
228   }
229   llvm::errs() << "\n";
230 
231   // Dump local macro directives.
232   for (auto *MD = State ? State->getLatest() : nullptr; MD;
233        MD = MD->getPrevious()) {
234     llvm::errs() << " ";
235     MD->dump();
236   }
237 
238   // Dump module macros.
239   llvm::DenseSet<ModuleMacro*> Active;
240   for (auto *MM : State ? State->getActiveModuleMacros(*this, II) : None)
241     Active.insert(MM);
242   llvm::DenseSet<ModuleMacro*> Visited;
243   llvm::SmallVector<ModuleMacro *, 16> Worklist(Leaf.begin(), Leaf.end());
244   while (!Worklist.empty()) {
245     auto *MM = Worklist.pop_back_val();
246     llvm::errs() << " ModuleMacro " << MM << " "
247                  << MM->getOwningModule()->getFullModuleName();
248     if (!MM->getMacroInfo())
249       llvm::errs() << " undef";
250 
251     if (Active.count(MM))
252       llvm::errs() << " active";
253     else if (!CurSubmoduleState->VisibleModules.isVisible(
254                  MM->getOwningModule()))
255       llvm::errs() << " hidden";
256     else if (MM->getMacroInfo())
257       llvm::errs() << " overridden";
258 
259     if (!MM->overrides().empty()) {
260       llvm::errs() << " overrides";
261       for (auto *O : MM->overrides()) {
262         llvm::errs() << " " << O->getOwningModule()->getFullModuleName();
263         if (Visited.insert(O).second)
264           Worklist.push_back(O);
265       }
266     }
267     llvm::errs() << "\n";
268     if (auto *MI = MM->getMacroInfo()) {
269       llvm::errs() << "  ";
270       MI->dump();
271       llvm::errs() << "\n";
272     }
273   }
274 }
275 
276 /// RegisterBuiltinMacro - Register the specified identifier in the identifier
277 /// table and mark it as a builtin macro to be expanded.
RegisterBuiltinMacro(Preprocessor & PP,const char * Name)278 static IdentifierInfo *RegisterBuiltinMacro(Preprocessor &PP, const char *Name){
279   // Get the identifier.
280   IdentifierInfo *Id = PP.getIdentifierInfo(Name);
281 
282   // Mark it as being a macro that is builtin.
283   MacroInfo *MI = PP.AllocateMacroInfo(SourceLocation());
284   MI->setIsBuiltinMacro();
285   PP.appendDefMacroDirective(Id, MI);
286   return Id;
287 }
288 
289 
290 /// RegisterBuiltinMacros - Register builtin macros, such as __LINE__ with the
291 /// identifier table.
RegisterBuiltinMacros()292 void Preprocessor::RegisterBuiltinMacros() {
293   Ident__LINE__ = RegisterBuiltinMacro(*this, "__LINE__");
294   Ident__FILE__ = RegisterBuiltinMacro(*this, "__FILE__");
295   Ident__DATE__ = RegisterBuiltinMacro(*this, "__DATE__");
296   Ident__TIME__ = RegisterBuiltinMacro(*this, "__TIME__");
297   Ident__COUNTER__ = RegisterBuiltinMacro(*this, "__COUNTER__");
298   Ident_Pragma  = RegisterBuiltinMacro(*this, "_Pragma");
299 
300   // C++ Standing Document Extensions.
301   if (LangOpts.CPlusPlus)
302     Ident__has_cpp_attribute =
303         RegisterBuiltinMacro(*this, "__has_cpp_attribute");
304   else
305     Ident__has_cpp_attribute = nullptr;
306 
307   // GCC Extensions.
308   Ident__BASE_FILE__     = RegisterBuiltinMacro(*this, "__BASE_FILE__");
309   Ident__INCLUDE_LEVEL__ = RegisterBuiltinMacro(*this, "__INCLUDE_LEVEL__");
310   Ident__TIMESTAMP__     = RegisterBuiltinMacro(*this, "__TIMESTAMP__");
311 
312   // Microsoft Extensions.
313   if (LangOpts.MicrosoftExt) {
314     Ident__identifier = RegisterBuiltinMacro(*this, "__identifier");
315     Ident__pragma = RegisterBuiltinMacro(*this, "__pragma");
316   } else {
317     Ident__identifier = nullptr;
318     Ident__pragma = nullptr;
319   }
320 
321   // Clang Extensions.
322   Ident__has_feature      = RegisterBuiltinMacro(*this, "__has_feature");
323   Ident__has_extension    = RegisterBuiltinMacro(*this, "__has_extension");
324   Ident__has_builtin      = RegisterBuiltinMacro(*this, "__has_builtin");
325   Ident__has_attribute    = RegisterBuiltinMacro(*this, "__has_attribute");
326   Ident__has_declspec = RegisterBuiltinMacro(*this, "__has_declspec_attribute");
327   Ident__has_include      = RegisterBuiltinMacro(*this, "__has_include");
328   Ident__has_include_next = RegisterBuiltinMacro(*this, "__has_include_next");
329   Ident__has_warning      = RegisterBuiltinMacro(*this, "__has_warning");
330   Ident__is_identifier    = RegisterBuiltinMacro(*this, "__is_identifier");
331 
332   // Modules.
333   Ident__building_module  = RegisterBuiltinMacro(*this, "__building_module");
334   if (!LangOpts.CurrentModule.empty())
335     Ident__MODULE__ = RegisterBuiltinMacro(*this, "__MODULE__");
336   else
337     Ident__MODULE__ = nullptr;
338 }
339 
340 /// isTrivialSingleTokenExpansion - Return true if MI, which has a single token
341 /// in its expansion, currently expands to that token literally.
isTrivialSingleTokenExpansion(const MacroInfo * MI,const IdentifierInfo * MacroIdent,Preprocessor & PP)342 static bool isTrivialSingleTokenExpansion(const MacroInfo *MI,
343                                           const IdentifierInfo *MacroIdent,
344                                           Preprocessor &PP) {
345   IdentifierInfo *II = MI->getReplacementToken(0).getIdentifierInfo();
346 
347   // If the token isn't an identifier, it's always literally expanded.
348   if (!II) return true;
349 
350   // If the information about this identifier is out of date, update it from
351   // the external source.
352   if (II->isOutOfDate())
353     PP.getExternalSource()->updateOutOfDateIdentifier(*II);
354 
355   // If the identifier is a macro, and if that macro is enabled, it may be
356   // expanded so it's not a trivial expansion.
357   if (auto *ExpansionMI = PP.getMacroInfo(II))
358     if (ExpansionMI->isEnabled() &&
359         // Fast expanding "#define X X" is ok, because X would be disabled.
360         II != MacroIdent)
361       return false;
362 
363   // If this is an object-like macro invocation, it is safe to trivially expand
364   // it.
365   if (MI->isObjectLike()) return true;
366 
367   // If this is a function-like macro invocation, it's safe to trivially expand
368   // as long as the identifier is not a macro argument.
369   return std::find(MI->arg_begin(), MI->arg_end(), II) == MI->arg_end();
370 
371 }
372 
373 
374 /// isNextPPTokenLParen - Determine whether the next preprocessor token to be
375 /// lexed is a '('.  If so, consume the token and return true, if not, this
376 /// method should have no observable side-effect on the lexed tokens.
isNextPPTokenLParen()377 bool Preprocessor::isNextPPTokenLParen() {
378   // Do some quick tests for rejection cases.
379   unsigned Val;
380   if (CurLexer)
381     Val = CurLexer->isNextPPTokenLParen();
382   else if (CurPTHLexer)
383     Val = CurPTHLexer->isNextPPTokenLParen();
384   else
385     Val = CurTokenLexer->isNextTokenLParen();
386 
387   if (Val == 2) {
388     // We have run off the end.  If it's a source file we don't
389     // examine enclosing ones (C99 5.1.1.2p4).  Otherwise walk up the
390     // macro stack.
391     if (CurPPLexer)
392       return false;
393     for (unsigned i = IncludeMacroStack.size(); i != 0; --i) {
394       IncludeStackInfo &Entry = IncludeMacroStack[i-1];
395       if (Entry.TheLexer)
396         Val = Entry.TheLexer->isNextPPTokenLParen();
397       else if (Entry.ThePTHLexer)
398         Val = Entry.ThePTHLexer->isNextPPTokenLParen();
399       else
400         Val = Entry.TheTokenLexer->isNextTokenLParen();
401 
402       if (Val != 2)
403         break;
404 
405       // Ran off the end of a source file?
406       if (Entry.ThePPLexer)
407         return false;
408     }
409   }
410 
411   // Okay, if we know that the token is a '(', lex it and return.  Otherwise we
412   // have found something that isn't a '(' or we found the end of the
413   // translation unit.  In either case, return false.
414   return Val == 1;
415 }
416 
417 /// HandleMacroExpandedIdentifier - If an identifier token is read that is to be
418 /// expanded as a macro, handle it and return the next token as 'Identifier'.
HandleMacroExpandedIdentifier(Token & Identifier,const MacroDefinition & M)419 bool Preprocessor::HandleMacroExpandedIdentifier(Token &Identifier,
420                                                  const MacroDefinition &M) {
421   MacroInfo *MI = M.getMacroInfo();
422 
423   // If this is a macro expansion in the "#if !defined(x)" line for the file,
424   // then the macro could expand to different things in other contexts, we need
425   // to disable the optimization in this case.
426   if (CurPPLexer) CurPPLexer->MIOpt.ExpandedMacro();
427 
428   // If this is a builtin macro, like __LINE__ or _Pragma, handle it specially.
429   if (MI->isBuiltinMacro()) {
430     if (Callbacks)
431       Callbacks->MacroExpands(Identifier, M, Identifier.getLocation(),
432                               /*Args=*/nullptr);
433     ExpandBuiltinMacro(Identifier);
434     return true;
435   }
436 
437   /// Args - If this is a function-like macro expansion, this contains,
438   /// for each macro argument, the list of tokens that were provided to the
439   /// invocation.
440   MacroArgs *Args = nullptr;
441 
442   // Remember where the end of the expansion occurred.  For an object-like
443   // macro, this is the identifier.  For a function-like macro, this is the ')'.
444   SourceLocation ExpansionEnd = Identifier.getLocation();
445 
446   // If this is a function-like macro, read the arguments.
447   if (MI->isFunctionLike()) {
448     // Remember that we are now parsing the arguments to a macro invocation.
449     // Preprocessor directives used inside macro arguments are not portable, and
450     // this enables the warning.
451     InMacroArgs = true;
452     Args = ReadFunctionLikeMacroArgs(Identifier, MI, ExpansionEnd);
453 
454     // Finished parsing args.
455     InMacroArgs = false;
456 
457     // If there was an error parsing the arguments, bail out.
458     if (!Args) return true;
459 
460     ++NumFnMacroExpanded;
461   } else {
462     ++NumMacroExpanded;
463   }
464 
465   // Notice that this macro has been used.
466   markMacroAsUsed(MI);
467 
468   // Remember where the token is expanded.
469   SourceLocation ExpandLoc = Identifier.getLocation();
470   SourceRange ExpansionRange(ExpandLoc, ExpansionEnd);
471 
472   if (Callbacks) {
473     if (InMacroArgs) {
474       // We can have macro expansion inside a conditional directive while
475       // reading the function macro arguments. To ensure, in that case, that
476       // MacroExpands callbacks still happen in source order, queue this
477       // callback to have it happen after the function macro callback.
478       DelayedMacroExpandsCallbacks.push_back(
479           MacroExpandsInfo(Identifier, M, ExpansionRange));
480     } else {
481       Callbacks->MacroExpands(Identifier, M, ExpansionRange, Args);
482       if (!DelayedMacroExpandsCallbacks.empty()) {
483         for (unsigned i=0, e = DelayedMacroExpandsCallbacks.size(); i!=e; ++i) {
484           MacroExpandsInfo &Info = DelayedMacroExpandsCallbacks[i];
485           // FIXME: We lose macro args info with delayed callback.
486           Callbacks->MacroExpands(Info.Tok, Info.MD, Info.Range,
487                                   /*Args=*/nullptr);
488         }
489         DelayedMacroExpandsCallbacks.clear();
490       }
491     }
492   }
493 
494   // If the macro definition is ambiguous, complain.
495   if (M.isAmbiguous()) {
496     Diag(Identifier, diag::warn_pp_ambiguous_macro)
497       << Identifier.getIdentifierInfo();
498     Diag(MI->getDefinitionLoc(), diag::note_pp_ambiguous_macro_chosen)
499       << Identifier.getIdentifierInfo();
500     M.forAllDefinitions([&](const MacroInfo *OtherMI) {
501       if (OtherMI != MI)
502         Diag(OtherMI->getDefinitionLoc(), diag::note_pp_ambiguous_macro_other)
503           << Identifier.getIdentifierInfo();
504     });
505   }
506 
507   // If we started lexing a macro, enter the macro expansion body.
508 
509   // If this macro expands to no tokens, don't bother to push it onto the
510   // expansion stack, only to take it right back off.
511   if (MI->getNumTokens() == 0) {
512     // No need for arg info.
513     if (Args) Args->destroy(*this);
514 
515     // Propagate whitespace info as if we had pushed, then popped,
516     // a macro context.
517     Identifier.setFlag(Token::LeadingEmptyMacro);
518     PropagateLineStartLeadingSpaceInfo(Identifier);
519     ++NumFastMacroExpanded;
520     return false;
521   } else if (MI->getNumTokens() == 1 &&
522              isTrivialSingleTokenExpansion(MI, Identifier.getIdentifierInfo(),
523                                            *this)) {
524     // Otherwise, if this macro expands into a single trivially-expanded
525     // token: expand it now.  This handles common cases like
526     // "#define VAL 42".
527 
528     // No need for arg info.
529     if (Args) Args->destroy(*this);
530 
531     // Propagate the isAtStartOfLine/hasLeadingSpace markers of the macro
532     // identifier to the expanded token.
533     bool isAtStartOfLine = Identifier.isAtStartOfLine();
534     bool hasLeadingSpace = Identifier.hasLeadingSpace();
535 
536     // Replace the result token.
537     Identifier = MI->getReplacementToken(0);
538 
539     // Restore the StartOfLine/LeadingSpace markers.
540     Identifier.setFlagValue(Token::StartOfLine , isAtStartOfLine);
541     Identifier.setFlagValue(Token::LeadingSpace, hasLeadingSpace);
542 
543     // Update the tokens location to include both its expansion and physical
544     // locations.
545     SourceLocation Loc =
546       SourceMgr.createExpansionLoc(Identifier.getLocation(), ExpandLoc,
547                                    ExpansionEnd,Identifier.getLength());
548     Identifier.setLocation(Loc);
549 
550     // If this is a disabled macro or #define X X, we must mark the result as
551     // unexpandable.
552     if (IdentifierInfo *NewII = Identifier.getIdentifierInfo()) {
553       if (MacroInfo *NewMI = getMacroInfo(NewII))
554         if (!NewMI->isEnabled() || NewMI == MI) {
555           Identifier.setFlag(Token::DisableExpand);
556           // Don't warn for "#define X X" like "#define bool bool" from
557           // stdbool.h.
558           if (NewMI != MI || MI->isFunctionLike())
559             Diag(Identifier, diag::pp_disabled_macro_expansion);
560         }
561     }
562 
563     // Since this is not an identifier token, it can't be macro expanded, so
564     // we're done.
565     ++NumFastMacroExpanded;
566     return true;
567   }
568 
569   // Start expanding the macro.
570   EnterMacro(Identifier, ExpansionEnd, MI, Args);
571   return false;
572 }
573 
574 enum Bracket {
575   Brace,
576   Paren
577 };
578 
579 /// CheckMatchedBrackets - Returns true if the braces and parentheses in the
580 /// token vector are properly nested.
CheckMatchedBrackets(const SmallVectorImpl<Token> & Tokens)581 static bool CheckMatchedBrackets(const SmallVectorImpl<Token> &Tokens) {
582   SmallVector<Bracket, 8> Brackets;
583   for (SmallVectorImpl<Token>::const_iterator I = Tokens.begin(),
584                                               E = Tokens.end();
585        I != E; ++I) {
586     if (I->is(tok::l_paren)) {
587       Brackets.push_back(Paren);
588     } else if (I->is(tok::r_paren)) {
589       if (Brackets.empty() || Brackets.back() == Brace)
590         return false;
591       Brackets.pop_back();
592     } else if (I->is(tok::l_brace)) {
593       Brackets.push_back(Brace);
594     } else if (I->is(tok::r_brace)) {
595       if (Brackets.empty() || Brackets.back() == Paren)
596         return false;
597       Brackets.pop_back();
598     }
599   }
600   return Brackets.empty();
601 }
602 
603 /// GenerateNewArgTokens - Returns true if OldTokens can be converted to a new
604 /// vector of tokens in NewTokens.  The new number of arguments will be placed
605 /// in NumArgs and the ranges which need to surrounded in parentheses will be
606 /// in ParenHints.
607 /// Returns false if the token stream cannot be changed.  If this is because
608 /// of an initializer list starting a macro argument, the range of those
609 /// initializer lists will be place in InitLists.
GenerateNewArgTokens(Preprocessor & PP,SmallVectorImpl<Token> & OldTokens,SmallVectorImpl<Token> & NewTokens,unsigned & NumArgs,SmallVectorImpl<SourceRange> & ParenHints,SmallVectorImpl<SourceRange> & InitLists)610 static bool GenerateNewArgTokens(Preprocessor &PP,
611                                  SmallVectorImpl<Token> &OldTokens,
612                                  SmallVectorImpl<Token> &NewTokens,
613                                  unsigned &NumArgs,
614                                  SmallVectorImpl<SourceRange> &ParenHints,
615                                  SmallVectorImpl<SourceRange> &InitLists) {
616   if (!CheckMatchedBrackets(OldTokens))
617     return false;
618 
619   // Once it is known that the brackets are matched, only a simple count of the
620   // braces is needed.
621   unsigned Braces = 0;
622 
623   // First token of a new macro argument.
624   SmallVectorImpl<Token>::iterator ArgStartIterator = OldTokens.begin();
625 
626   // First closing brace in a new macro argument.  Used to generate
627   // SourceRanges for InitLists.
628   SmallVectorImpl<Token>::iterator ClosingBrace = OldTokens.end();
629   NumArgs = 0;
630   Token TempToken;
631   // Set to true when a macro separator token is found inside a braced list.
632   // If true, the fixed argument spans multiple old arguments and ParenHints
633   // will be updated.
634   bool FoundSeparatorToken = false;
635   for (SmallVectorImpl<Token>::iterator I = OldTokens.begin(),
636                                         E = OldTokens.end();
637        I != E; ++I) {
638     if (I->is(tok::l_brace)) {
639       ++Braces;
640     } else if (I->is(tok::r_brace)) {
641       --Braces;
642       if (Braces == 0 && ClosingBrace == E && FoundSeparatorToken)
643         ClosingBrace = I;
644     } else if (I->is(tok::eof)) {
645       // EOF token is used to separate macro arguments
646       if (Braces != 0) {
647         // Assume comma separator is actually braced list separator and change
648         // it back to a comma.
649         FoundSeparatorToken = true;
650         I->setKind(tok::comma);
651         I->setLength(1);
652       } else { // Braces == 0
653         // Separator token still separates arguments.
654         ++NumArgs;
655 
656         // If the argument starts with a brace, it can't be fixed with
657         // parentheses.  A different diagnostic will be given.
658         if (FoundSeparatorToken && ArgStartIterator->is(tok::l_brace)) {
659           InitLists.push_back(
660               SourceRange(ArgStartIterator->getLocation(),
661                           PP.getLocForEndOfToken(ClosingBrace->getLocation())));
662           ClosingBrace = E;
663         }
664 
665         // Add left paren
666         if (FoundSeparatorToken) {
667           TempToken.startToken();
668           TempToken.setKind(tok::l_paren);
669           TempToken.setLocation(ArgStartIterator->getLocation());
670           TempToken.setLength(0);
671           NewTokens.push_back(TempToken);
672         }
673 
674         // Copy over argument tokens
675         NewTokens.insert(NewTokens.end(), ArgStartIterator, I);
676 
677         // Add right paren and store the paren locations in ParenHints
678         if (FoundSeparatorToken) {
679           SourceLocation Loc = PP.getLocForEndOfToken((I - 1)->getLocation());
680           TempToken.startToken();
681           TempToken.setKind(tok::r_paren);
682           TempToken.setLocation(Loc);
683           TempToken.setLength(0);
684           NewTokens.push_back(TempToken);
685           ParenHints.push_back(SourceRange(ArgStartIterator->getLocation(),
686                                            Loc));
687         }
688 
689         // Copy separator token
690         NewTokens.push_back(*I);
691 
692         // Reset values
693         ArgStartIterator = I + 1;
694         FoundSeparatorToken = false;
695       }
696     }
697   }
698 
699   return !ParenHints.empty() && InitLists.empty();
700 }
701 
702 /// ReadFunctionLikeMacroArgs - After reading "MACRO" and knowing that the next
703 /// token is the '(' of the macro, this method is invoked to read all of the
704 /// actual arguments specified for the macro invocation.  This returns null on
705 /// error.
ReadFunctionLikeMacroArgs(Token & MacroName,MacroInfo * MI,SourceLocation & MacroEnd)706 MacroArgs *Preprocessor::ReadFunctionLikeMacroArgs(Token &MacroName,
707                                                    MacroInfo *MI,
708                                                    SourceLocation &MacroEnd) {
709   // The number of fixed arguments to parse.
710   unsigned NumFixedArgsLeft = MI->getNumArgs();
711   bool isVariadic = MI->isVariadic();
712 
713   // Outer loop, while there are more arguments, keep reading them.
714   Token Tok;
715 
716   // Read arguments as unexpanded tokens.  This avoids issues, e.g., where
717   // an argument value in a macro could expand to ',' or '(' or ')'.
718   LexUnexpandedToken(Tok);
719   assert(Tok.is(tok::l_paren) && "Error computing l-paren-ness?");
720 
721   // ArgTokens - Build up a list of tokens that make up each argument.  Each
722   // argument is separated by an EOF token.  Use a SmallVector so we can avoid
723   // heap allocations in the common case.
724   SmallVector<Token, 64> ArgTokens;
725   bool ContainsCodeCompletionTok = false;
726   bool FoundElidedComma = false;
727 
728   SourceLocation TooManyArgsLoc;
729 
730   unsigned NumActuals = 0;
731   while (Tok.isNot(tok::r_paren)) {
732     if (ContainsCodeCompletionTok && Tok.isOneOf(tok::eof, tok::eod))
733       break;
734 
735     assert(Tok.isOneOf(tok::l_paren, tok::comma) &&
736            "only expect argument separators here");
737 
738     unsigned ArgTokenStart = ArgTokens.size();
739     SourceLocation ArgStartLoc = Tok.getLocation();
740 
741     // C99 6.10.3p11: Keep track of the number of l_parens we have seen.  Note
742     // that we already consumed the first one.
743     unsigned NumParens = 0;
744 
745     while (1) {
746       // Read arguments as unexpanded tokens.  This avoids issues, e.g., where
747       // an argument value in a macro could expand to ',' or '(' or ')'.
748       LexUnexpandedToken(Tok);
749 
750       if (Tok.isOneOf(tok::eof, tok::eod)) { // "#if f(<eof>" & "#if f(\n"
751         if (!ContainsCodeCompletionTok) {
752           Diag(MacroName, diag::err_unterm_macro_invoc);
753           Diag(MI->getDefinitionLoc(), diag::note_macro_here)
754             << MacroName.getIdentifierInfo();
755           // Do not lose the EOF/EOD.  Return it to the client.
756           MacroName = Tok;
757           return nullptr;
758         }
759         // Do not lose the EOF/EOD.
760         auto Toks = llvm::make_unique<Token[]>(1);
761         Toks[0] = Tok;
762         EnterTokenStream(std::move(Toks), 1, true);
763         break;
764       } else if (Tok.is(tok::r_paren)) {
765         // If we found the ) token, the macro arg list is done.
766         if (NumParens-- == 0) {
767           MacroEnd = Tok.getLocation();
768           if (!ArgTokens.empty() &&
769               ArgTokens.back().commaAfterElided()) {
770             FoundElidedComma = true;
771           }
772           break;
773         }
774       } else if (Tok.is(tok::l_paren)) {
775         ++NumParens;
776       } else if (Tok.is(tok::comma) && NumParens == 0 &&
777                  !(Tok.getFlags() & Token::IgnoredComma)) {
778         // In Microsoft-compatibility mode, single commas from nested macro
779         // expansions should not be considered as argument separators. We test
780         // for this with the IgnoredComma token flag above.
781 
782         // Comma ends this argument if there are more fixed arguments expected.
783         // However, if this is a variadic macro, and this is part of the
784         // variadic part, then the comma is just an argument token.
785         if (!isVariadic) break;
786         if (NumFixedArgsLeft > 1)
787           break;
788       } else if (Tok.is(tok::comment) && !KeepMacroComments) {
789         // If this is a comment token in the argument list and we're just in
790         // -C mode (not -CC mode), discard the comment.
791         continue;
792       } else if (!Tok.isAnnotation() && Tok.getIdentifierInfo() != nullptr) {
793         // Reading macro arguments can cause macros that we are currently
794         // expanding from to be popped off the expansion stack.  Doing so causes
795         // them to be reenabled for expansion.  Here we record whether any
796         // identifiers we lex as macro arguments correspond to disabled macros.
797         // If so, we mark the token as noexpand.  This is a subtle aspect of
798         // C99 6.10.3.4p2.
799         if (MacroInfo *MI = getMacroInfo(Tok.getIdentifierInfo()))
800           if (!MI->isEnabled())
801             Tok.setFlag(Token::DisableExpand);
802       } else if (Tok.is(tok::code_completion)) {
803         ContainsCodeCompletionTok = true;
804         if (CodeComplete)
805           CodeComplete->CodeCompleteMacroArgument(MacroName.getIdentifierInfo(),
806                                                   MI, NumActuals);
807         // Don't mark that we reached the code-completion point because the
808         // parser is going to handle the token and there will be another
809         // code-completion callback.
810       }
811 
812       ArgTokens.push_back(Tok);
813     }
814 
815     // If this was an empty argument list foo(), don't add this as an empty
816     // argument.
817     if (ArgTokens.empty() && Tok.getKind() == tok::r_paren)
818       break;
819 
820     // If this is not a variadic macro, and too many args were specified, emit
821     // an error.
822     if (!isVariadic && NumFixedArgsLeft == 0 && TooManyArgsLoc.isInvalid()) {
823       if (ArgTokens.size() != ArgTokenStart)
824         TooManyArgsLoc = ArgTokens[ArgTokenStart].getLocation();
825       else
826         TooManyArgsLoc = ArgStartLoc;
827     }
828 
829     // Empty arguments are standard in C99 and C++0x, and are supported as an
830     // extension in other modes.
831     if (ArgTokens.size() == ArgTokenStart && !LangOpts.C99)
832       Diag(Tok, LangOpts.CPlusPlus11 ?
833            diag::warn_cxx98_compat_empty_fnmacro_arg :
834            diag::ext_empty_fnmacro_arg);
835 
836     // Add a marker EOF token to the end of the token list for this argument.
837     Token EOFTok;
838     EOFTok.startToken();
839     EOFTok.setKind(tok::eof);
840     EOFTok.setLocation(Tok.getLocation());
841     EOFTok.setLength(0);
842     ArgTokens.push_back(EOFTok);
843     ++NumActuals;
844     if (!ContainsCodeCompletionTok && NumFixedArgsLeft != 0)
845       --NumFixedArgsLeft;
846   }
847 
848   // Okay, we either found the r_paren.  Check to see if we parsed too few
849   // arguments.
850   unsigned MinArgsExpected = MI->getNumArgs();
851 
852   // If this is not a variadic macro, and too many args were specified, emit
853   // an error.
854   if (!isVariadic && NumActuals > MinArgsExpected &&
855       !ContainsCodeCompletionTok) {
856     // Emit the diagnostic at the macro name in case there is a missing ).
857     // Emitting it at the , could be far away from the macro name.
858     Diag(TooManyArgsLoc, diag::err_too_many_args_in_macro_invoc);
859     Diag(MI->getDefinitionLoc(), diag::note_macro_here)
860       << MacroName.getIdentifierInfo();
861 
862     // Commas from braced initializer lists will be treated as argument
863     // separators inside macros.  Attempt to correct for this with parentheses.
864     // TODO: See if this can be generalized to angle brackets for templates
865     // inside macro arguments.
866 
867     SmallVector<Token, 4> FixedArgTokens;
868     unsigned FixedNumArgs = 0;
869     SmallVector<SourceRange, 4> ParenHints, InitLists;
870     if (!GenerateNewArgTokens(*this, ArgTokens, FixedArgTokens, FixedNumArgs,
871                               ParenHints, InitLists)) {
872       if (!InitLists.empty()) {
873         DiagnosticBuilder DB =
874             Diag(MacroName,
875                  diag::note_init_list_at_beginning_of_macro_argument);
876         for (SourceRange Range : InitLists)
877           DB << Range;
878       }
879       return nullptr;
880     }
881     if (FixedNumArgs != MinArgsExpected)
882       return nullptr;
883 
884     DiagnosticBuilder DB = Diag(MacroName, diag::note_suggest_parens_for_macro);
885     for (SourceRange ParenLocation : ParenHints) {
886       DB << FixItHint::CreateInsertion(ParenLocation.getBegin(), "(");
887       DB << FixItHint::CreateInsertion(ParenLocation.getEnd(), ")");
888     }
889     ArgTokens.swap(FixedArgTokens);
890     NumActuals = FixedNumArgs;
891   }
892 
893   // See MacroArgs instance var for description of this.
894   bool isVarargsElided = false;
895 
896   if (ContainsCodeCompletionTok) {
897     // Recover from not-fully-formed macro invocation during code-completion.
898     Token EOFTok;
899     EOFTok.startToken();
900     EOFTok.setKind(tok::eof);
901     EOFTok.setLocation(Tok.getLocation());
902     EOFTok.setLength(0);
903     for (; NumActuals < MinArgsExpected; ++NumActuals)
904       ArgTokens.push_back(EOFTok);
905   }
906 
907   if (NumActuals < MinArgsExpected) {
908     // There are several cases where too few arguments is ok, handle them now.
909     if (NumActuals == 0 && MinArgsExpected == 1) {
910       // #define A(X)  or  #define A(...)   ---> A()
911 
912       // If there is exactly one argument, and that argument is missing,
913       // then we have an empty "()" argument empty list.  This is fine, even if
914       // the macro expects one argument (the argument is just empty).
915       isVarargsElided = MI->isVariadic();
916     } else if ((FoundElidedComma || MI->isVariadic()) &&
917                (NumActuals+1 == MinArgsExpected ||  // A(x, ...) -> A(X)
918                 (NumActuals == 0 && MinArgsExpected == 2))) {// A(x,...) -> A()
919       // Varargs where the named vararg parameter is missing: OK as extension.
920       //   #define A(x, ...)
921       //   A("blah")
922       //
923       // If the macro contains the comma pasting extension, the diagnostic
924       // is suppressed; we know we'll get another diagnostic later.
925       if (!MI->hasCommaPasting()) {
926         Diag(Tok, diag::ext_missing_varargs_arg);
927         Diag(MI->getDefinitionLoc(), diag::note_macro_here)
928           << MacroName.getIdentifierInfo();
929       }
930 
931       // Remember this occurred, allowing us to elide the comma when used for
932       // cases like:
933       //   #define A(x, foo...) blah(a, ## foo)
934       //   #define B(x, ...) blah(a, ## __VA_ARGS__)
935       //   #define C(...) blah(a, ## __VA_ARGS__)
936       //  A(x) B(x) C()
937       isVarargsElided = true;
938     } else if (!ContainsCodeCompletionTok) {
939       // Otherwise, emit the error.
940       Diag(Tok, diag::err_too_few_args_in_macro_invoc);
941       Diag(MI->getDefinitionLoc(), diag::note_macro_here)
942         << MacroName.getIdentifierInfo();
943       return nullptr;
944     }
945 
946     // Add a marker EOF token to the end of the token list for this argument.
947     SourceLocation EndLoc = Tok.getLocation();
948     Tok.startToken();
949     Tok.setKind(tok::eof);
950     Tok.setLocation(EndLoc);
951     Tok.setLength(0);
952     ArgTokens.push_back(Tok);
953 
954     // If we expect two arguments, add both as empty.
955     if (NumActuals == 0 && MinArgsExpected == 2)
956       ArgTokens.push_back(Tok);
957 
958   } else if (NumActuals > MinArgsExpected && !MI->isVariadic() &&
959              !ContainsCodeCompletionTok) {
960     // Emit the diagnostic at the macro name in case there is a missing ).
961     // Emitting it at the , could be far away from the macro name.
962     Diag(MacroName, diag::err_too_many_args_in_macro_invoc);
963     Diag(MI->getDefinitionLoc(), diag::note_macro_here)
964       << MacroName.getIdentifierInfo();
965     return nullptr;
966   }
967 
968   return MacroArgs::create(MI, ArgTokens, isVarargsElided, *this);
969 }
970 
971 /// \brief Keeps macro expanded tokens for TokenLexers.
972 //
973 /// Works like a stack; a TokenLexer adds the macro expanded tokens that is
974 /// going to lex in the cache and when it finishes the tokens are removed
975 /// from the end of the cache.
cacheMacroExpandedTokens(TokenLexer * tokLexer,ArrayRef<Token> tokens)976 Token *Preprocessor::cacheMacroExpandedTokens(TokenLexer *tokLexer,
977                                               ArrayRef<Token> tokens) {
978   assert(tokLexer);
979   if (tokens.empty())
980     return nullptr;
981 
982   size_t newIndex = MacroExpandedTokens.size();
983   bool cacheNeedsToGrow = tokens.size() >
984                       MacroExpandedTokens.capacity()-MacroExpandedTokens.size();
985   MacroExpandedTokens.append(tokens.begin(), tokens.end());
986 
987   if (cacheNeedsToGrow) {
988     // Go through all the TokenLexers whose 'Tokens' pointer points in the
989     // buffer and update the pointers to the (potential) new buffer array.
990     for (unsigned i = 0, e = MacroExpandingLexersStack.size(); i != e; ++i) {
991       TokenLexer *prevLexer;
992       size_t tokIndex;
993       std::tie(prevLexer, tokIndex) = MacroExpandingLexersStack[i];
994       prevLexer->Tokens = MacroExpandedTokens.data() + tokIndex;
995     }
996   }
997 
998   MacroExpandingLexersStack.push_back(std::make_pair(tokLexer, newIndex));
999   return MacroExpandedTokens.data() + newIndex;
1000 }
1001 
removeCachedMacroExpandedTokensOfLastLexer()1002 void Preprocessor::removeCachedMacroExpandedTokensOfLastLexer() {
1003   assert(!MacroExpandingLexersStack.empty());
1004   size_t tokIndex = MacroExpandingLexersStack.back().second;
1005   assert(tokIndex < MacroExpandedTokens.size());
1006   // Pop the cached macro expanded tokens from the end.
1007   MacroExpandedTokens.resize(tokIndex);
1008   MacroExpandingLexersStack.pop_back();
1009 }
1010 
1011 /// ComputeDATE_TIME - Compute the current time, enter it into the specified
1012 /// scratch buffer, then return DATELoc/TIMELoc locations with the position of
1013 /// the identifier tokens inserted.
ComputeDATE_TIME(SourceLocation & DATELoc,SourceLocation & TIMELoc,Preprocessor & PP)1014 static void ComputeDATE_TIME(SourceLocation &DATELoc, SourceLocation &TIMELoc,
1015                              Preprocessor &PP) {
1016   time_t TT = time(nullptr);
1017   struct tm *TM = localtime(&TT);
1018 
1019   static const char * const Months[] = {
1020     "Jan","Feb","Mar","Apr","May","Jun","Jul","Aug","Sep","Oct","Nov","Dec"
1021   };
1022 
1023   {
1024     SmallString<32> TmpBuffer;
1025     llvm::raw_svector_ostream TmpStream(TmpBuffer);
1026     TmpStream << llvm::format("\"%s %2d %4d\"", Months[TM->tm_mon],
1027                               TM->tm_mday, TM->tm_year + 1900);
1028     Token TmpTok;
1029     TmpTok.startToken();
1030     PP.CreateString(TmpStream.str(), TmpTok);
1031     DATELoc = TmpTok.getLocation();
1032   }
1033 
1034   {
1035     SmallString<32> TmpBuffer;
1036     llvm::raw_svector_ostream TmpStream(TmpBuffer);
1037     TmpStream << llvm::format("\"%02d:%02d:%02d\"",
1038                               TM->tm_hour, TM->tm_min, TM->tm_sec);
1039     Token TmpTok;
1040     TmpTok.startToken();
1041     PP.CreateString(TmpStream.str(), TmpTok);
1042     TIMELoc = TmpTok.getLocation();
1043   }
1044 }
1045 
1046 
1047 /// HasFeature - Return true if we recognize and implement the feature
1048 /// specified by the identifier as a standard language feature.
HasFeature(const Preprocessor & PP,StringRef Feature)1049 static bool HasFeature(const Preprocessor &PP, StringRef Feature) {
1050   const LangOptions &LangOpts = PP.getLangOpts();
1051 
1052   // Normalize the feature name, __foo__ becomes foo.
1053   if (Feature.startswith("__") && Feature.endswith("__") && Feature.size() >= 4)
1054     Feature = Feature.substr(2, Feature.size() - 4);
1055 
1056   return llvm::StringSwitch<bool>(Feature)
1057       .Case("address_sanitizer",
1058             LangOpts.Sanitize.hasOneOf(SanitizerKind::Address |
1059                                        SanitizerKind::KernelAddress))
1060       .Case("assume_nonnull", true)
1061       .Case("attribute_analyzer_noreturn", true)
1062       .Case("attribute_availability", true)
1063       .Case("attribute_availability_with_message", true)
1064       .Case("attribute_availability_app_extension", true)
1065       .Case("attribute_availability_with_version_underscores", true)
1066       .Case("attribute_availability_tvos", true)
1067       .Case("attribute_availability_watchos", true)
1068       .Case("attribute_availability_with_strict", true)
1069       .Case("attribute_availability_with_replacement", true)
1070       .Case("attribute_availability_in_templates", true)
1071       .Case("attribute_cf_returns_not_retained", true)
1072       .Case("attribute_cf_returns_retained", true)
1073       .Case("attribute_cf_returns_on_parameters", true)
1074       .Case("attribute_deprecated_with_message", true)
1075       .Case("attribute_deprecated_with_replacement", true)
1076       .Case("attribute_ext_vector_type", true)
1077       .Case("attribute_ns_returns_not_retained", true)
1078       .Case("attribute_ns_returns_retained", true)
1079       .Case("attribute_ns_consumes_self", true)
1080       .Case("attribute_ns_consumed", true)
1081       .Case("attribute_cf_consumed", true)
1082       .Case("attribute_objc_ivar_unused", true)
1083       .Case("attribute_objc_method_family", true)
1084       .Case("attribute_overloadable", true)
1085       .Case("attribute_unavailable_with_message", true)
1086       .Case("attribute_unused_on_fields", true)
1087       .Case("blocks", LangOpts.Blocks)
1088       .Case("c_thread_safety_attributes", true)
1089       .Case("cxx_exceptions", LangOpts.CXXExceptions)
1090       .Case("cxx_rtti", LangOpts.RTTI && LangOpts.RTTIData)
1091       .Case("enumerator_attributes", true)
1092       .Case("nullability", true)
1093       .Case("memory_sanitizer", LangOpts.Sanitize.has(SanitizerKind::Memory))
1094       .Case("thread_sanitizer", LangOpts.Sanitize.has(SanitizerKind::Thread))
1095       .Case("dataflow_sanitizer", LangOpts.Sanitize.has(SanitizerKind::DataFlow))
1096       .Case("efficiency_sanitizer",
1097             LangOpts.Sanitize.hasOneOf(SanitizerKind::Efficiency))
1098       // Objective-C features
1099       .Case("objc_arr", LangOpts.ObjCAutoRefCount) // FIXME: REMOVE?
1100       .Case("objc_arc", LangOpts.ObjCAutoRefCount)
1101       .Case("objc_arc_weak", LangOpts.ObjCWeak)
1102       .Case("objc_default_synthesize_properties", LangOpts.ObjC2)
1103       .Case("objc_fixed_enum", LangOpts.ObjC2)
1104       .Case("objc_instancetype", LangOpts.ObjC2)
1105       .Case("objc_kindof", LangOpts.ObjC2)
1106       .Case("objc_modules", LangOpts.ObjC2 && LangOpts.Modules)
1107       .Case("objc_nonfragile_abi", LangOpts.ObjCRuntime.isNonFragile())
1108       .Case("objc_property_explicit_atomic",
1109             true) // Does clang support explicit "atomic" keyword?
1110       .Case("objc_protocol_qualifier_mangling", true)
1111       .Case("objc_weak_class", LangOpts.ObjCRuntime.hasWeakClassImport())
1112       .Case("ownership_holds", true)
1113       .Case("ownership_returns", true)
1114       .Case("ownership_takes", true)
1115       .Case("objc_bool", true)
1116       .Case("objc_subscripting", LangOpts.ObjCRuntime.isNonFragile())
1117       .Case("objc_array_literals", LangOpts.ObjC2)
1118       .Case("objc_dictionary_literals", LangOpts.ObjC2)
1119       .Case("objc_boxed_expressions", LangOpts.ObjC2)
1120       .Case("objc_boxed_nsvalue_expressions", LangOpts.ObjC2)
1121       .Case("arc_cf_code_audited", true)
1122       .Case("objc_bridge_id", true)
1123       .Case("objc_bridge_id_on_typedefs", true)
1124       .Case("objc_generics", LangOpts.ObjC2)
1125       .Case("objc_generics_variance", LangOpts.ObjC2)
1126       .Case("objc_class_property", LangOpts.ObjC2)
1127       // C11 features
1128       .Case("c_alignas", LangOpts.C11)
1129       .Case("c_alignof", LangOpts.C11)
1130       .Case("c_atomic", LangOpts.C11)
1131       .Case("c_generic_selections", LangOpts.C11)
1132       .Case("c_static_assert", LangOpts.C11)
1133       .Case("c_thread_local",
1134             LangOpts.C11 && PP.getTargetInfo().isTLSSupported())
1135       // C++11 features
1136       .Case("cxx_access_control_sfinae", LangOpts.CPlusPlus11)
1137       .Case("cxx_alias_templates", LangOpts.CPlusPlus11)
1138       .Case("cxx_alignas", LangOpts.CPlusPlus11)
1139       .Case("cxx_alignof", LangOpts.CPlusPlus11)
1140       .Case("cxx_atomic", LangOpts.CPlusPlus11)
1141       .Case("cxx_attributes", LangOpts.CPlusPlus11)
1142       .Case("cxx_auto_type", LangOpts.CPlusPlus11)
1143       .Case("cxx_constexpr", LangOpts.CPlusPlus11)
1144       .Case("cxx_decltype", LangOpts.CPlusPlus11)
1145       .Case("cxx_decltype_incomplete_return_types", LangOpts.CPlusPlus11)
1146       .Case("cxx_default_function_template_args", LangOpts.CPlusPlus11)
1147       .Case("cxx_defaulted_functions", LangOpts.CPlusPlus11)
1148       .Case("cxx_delegating_constructors", LangOpts.CPlusPlus11)
1149       .Case("cxx_deleted_functions", LangOpts.CPlusPlus11)
1150       .Case("cxx_explicit_conversions", LangOpts.CPlusPlus11)
1151       .Case("cxx_generalized_initializers", LangOpts.CPlusPlus11)
1152       .Case("cxx_implicit_moves", LangOpts.CPlusPlus11)
1153       .Case("cxx_inheriting_constructors", LangOpts.CPlusPlus11)
1154       .Case("cxx_inline_namespaces", LangOpts.CPlusPlus11)
1155       .Case("cxx_lambdas", LangOpts.CPlusPlus11)
1156       .Case("cxx_local_type_template_args", LangOpts.CPlusPlus11)
1157       .Case("cxx_nonstatic_member_init", LangOpts.CPlusPlus11)
1158       .Case("cxx_noexcept", LangOpts.CPlusPlus11)
1159       .Case("cxx_nullptr", LangOpts.CPlusPlus11)
1160       .Case("cxx_override_control", LangOpts.CPlusPlus11)
1161       .Case("cxx_range_for", LangOpts.CPlusPlus11)
1162       .Case("cxx_raw_string_literals", LangOpts.CPlusPlus11)
1163       .Case("cxx_reference_qualified_functions", LangOpts.CPlusPlus11)
1164       .Case("cxx_rvalue_references", LangOpts.CPlusPlus11)
1165       .Case("cxx_strong_enums", LangOpts.CPlusPlus11)
1166       .Case("cxx_static_assert", LangOpts.CPlusPlus11)
1167       .Case("cxx_thread_local",
1168             LangOpts.CPlusPlus11 && PP.getTargetInfo().isTLSSupported())
1169       .Case("cxx_trailing_return", LangOpts.CPlusPlus11)
1170       .Case("cxx_unicode_literals", LangOpts.CPlusPlus11)
1171       .Case("cxx_unrestricted_unions", LangOpts.CPlusPlus11)
1172       .Case("cxx_user_literals", LangOpts.CPlusPlus11)
1173       .Case("cxx_variadic_templates", LangOpts.CPlusPlus11)
1174       // C++1y features
1175       .Case("cxx_aggregate_nsdmi", LangOpts.CPlusPlus14)
1176       .Case("cxx_binary_literals", LangOpts.CPlusPlus14)
1177       .Case("cxx_contextual_conversions", LangOpts.CPlusPlus14)
1178       .Case("cxx_decltype_auto", LangOpts.CPlusPlus14)
1179       .Case("cxx_generic_lambdas", LangOpts.CPlusPlus14)
1180       .Case("cxx_init_captures", LangOpts.CPlusPlus14)
1181       .Case("cxx_relaxed_constexpr", LangOpts.CPlusPlus14)
1182       .Case("cxx_return_type_deduction", LangOpts.CPlusPlus14)
1183       .Case("cxx_variable_templates", LangOpts.CPlusPlus14)
1184       // C++ TSes
1185       //.Case("cxx_runtime_arrays", LangOpts.CPlusPlusTSArrays)
1186       //.Case("cxx_concepts", LangOpts.CPlusPlusTSConcepts)
1187       // FIXME: Should this be __has_feature or __has_extension?
1188       //.Case("raw_invocation_type", LangOpts.CPlusPlus)
1189       // Type traits
1190       // N.B. Additional type traits should not be added to the following list.
1191       // Instead, they should be detected by has_extension.
1192       .Case("has_nothrow_assign", LangOpts.CPlusPlus)
1193       .Case("has_nothrow_copy", LangOpts.CPlusPlus)
1194       .Case("has_nothrow_constructor", LangOpts.CPlusPlus)
1195       .Case("has_trivial_assign", LangOpts.CPlusPlus)
1196       .Case("has_trivial_copy", LangOpts.CPlusPlus)
1197       .Case("has_trivial_constructor", LangOpts.CPlusPlus)
1198       .Case("has_trivial_destructor", LangOpts.CPlusPlus)
1199       .Case("has_virtual_destructor", LangOpts.CPlusPlus)
1200       .Case("is_abstract", LangOpts.CPlusPlus)
1201       .Case("is_base_of", LangOpts.CPlusPlus)
1202       .Case("is_class", LangOpts.CPlusPlus)
1203       .Case("is_constructible", LangOpts.CPlusPlus)
1204       .Case("is_convertible_to", LangOpts.CPlusPlus)
1205       .Case("is_empty", LangOpts.CPlusPlus)
1206       .Case("is_enum", LangOpts.CPlusPlus)
1207       .Case("is_final", LangOpts.CPlusPlus)
1208       .Case("is_literal", LangOpts.CPlusPlus)
1209       .Case("is_standard_layout", LangOpts.CPlusPlus)
1210       .Case("is_pod", LangOpts.CPlusPlus)
1211       .Case("is_polymorphic", LangOpts.CPlusPlus)
1212       .Case("is_sealed", LangOpts.CPlusPlus && LangOpts.MicrosoftExt)
1213       .Case("is_trivial", LangOpts.CPlusPlus)
1214       .Case("is_trivially_assignable", LangOpts.CPlusPlus)
1215       .Case("is_trivially_constructible", LangOpts.CPlusPlus)
1216       .Case("is_trivially_copyable", LangOpts.CPlusPlus)
1217       .Case("is_union", LangOpts.CPlusPlus)
1218       .Case("modules", LangOpts.Modules)
1219       .Case("safe_stack", LangOpts.Sanitize.has(SanitizerKind::SafeStack))
1220       .Case("tls", PP.getTargetInfo().isTLSSupported())
1221       .Case("underlying_type", LangOpts.CPlusPlus)
1222       .Default(false);
1223 }
1224 
1225 /// HasExtension - Return true if we recognize and implement the feature
1226 /// specified by the identifier, either as an extension or a standard language
1227 /// feature.
HasExtension(const Preprocessor & PP,StringRef Extension)1228 static bool HasExtension(const Preprocessor &PP, StringRef Extension) {
1229   if (HasFeature(PP, Extension))
1230     return true;
1231 
1232   // If the use of an extension results in an error diagnostic, extensions are
1233   // effectively unavailable, so just return false here.
1234   if (PP.getDiagnostics().getExtensionHandlingBehavior() >=
1235       diag::Severity::Error)
1236     return false;
1237 
1238   const LangOptions &LangOpts = PP.getLangOpts();
1239 
1240   // Normalize the extension name, __foo__ becomes foo.
1241   if (Extension.startswith("__") && Extension.endswith("__") &&
1242       Extension.size() >= 4)
1243     Extension = Extension.substr(2, Extension.size() - 4);
1244 
1245   // Because we inherit the feature list from HasFeature, this string switch
1246   // must be less restrictive than HasFeature's.
1247   return llvm::StringSwitch<bool>(Extension)
1248            // C11 features supported by other languages as extensions.
1249            .Case("c_alignas", true)
1250            .Case("c_alignof", true)
1251            .Case("c_atomic", true)
1252            .Case("c_generic_selections", true)
1253            .Case("c_static_assert", true)
1254            .Case("c_thread_local", PP.getTargetInfo().isTLSSupported())
1255            // C++11 features supported by other languages as extensions.
1256            .Case("cxx_atomic", LangOpts.CPlusPlus)
1257            .Case("cxx_deleted_functions", LangOpts.CPlusPlus)
1258            .Case("cxx_explicit_conversions", LangOpts.CPlusPlus)
1259            .Case("cxx_inline_namespaces", LangOpts.CPlusPlus)
1260            .Case("cxx_local_type_template_args", LangOpts.CPlusPlus)
1261            .Case("cxx_nonstatic_member_init", LangOpts.CPlusPlus)
1262            .Case("cxx_override_control", LangOpts.CPlusPlus)
1263            .Case("cxx_range_for", LangOpts.CPlusPlus)
1264            .Case("cxx_reference_qualified_functions", LangOpts.CPlusPlus)
1265            .Case("cxx_rvalue_references", LangOpts.CPlusPlus)
1266            .Case("cxx_variadic_templates", LangOpts.CPlusPlus)
1267            // C++1y features supported by other languages as extensions.
1268            .Case("cxx_binary_literals", true)
1269            .Case("cxx_init_captures", LangOpts.CPlusPlus11)
1270            .Case("cxx_variable_templates", LangOpts.CPlusPlus)
1271            .Default(false);
1272 }
1273 
1274 /// EvaluateHasIncludeCommon - Process a '__has_include("path")'
1275 /// or '__has_include_next("path")' expression.
1276 /// Returns true if successful.
EvaluateHasIncludeCommon(Token & Tok,IdentifierInfo * II,Preprocessor & PP,const DirectoryLookup * LookupFrom,const FileEntry * LookupFromFile)1277 static bool EvaluateHasIncludeCommon(Token &Tok,
1278                                      IdentifierInfo *II, Preprocessor &PP,
1279                                      const DirectoryLookup *LookupFrom,
1280                                      const FileEntry *LookupFromFile) {
1281   // Save the location of the current token.  If a '(' is later found, use
1282   // that location.  If not, use the end of this location instead.
1283   SourceLocation LParenLoc = Tok.getLocation();
1284 
1285   // These expressions are only allowed within a preprocessor directive.
1286   if (!PP.isParsingIfOrElifDirective()) {
1287     PP.Diag(LParenLoc, diag::err_pp_directive_required) << II->getName();
1288     // Return a valid identifier token.
1289     assert(Tok.is(tok::identifier));
1290     Tok.setIdentifierInfo(II);
1291     return false;
1292   }
1293 
1294   // Get '('.
1295   PP.LexNonComment(Tok);
1296 
1297   // Ensure we have a '('.
1298   if (Tok.isNot(tok::l_paren)) {
1299     // No '(', use end of last token.
1300     LParenLoc = PP.getLocForEndOfToken(LParenLoc);
1301     PP.Diag(LParenLoc, diag::err_pp_expected_after) << II << tok::l_paren;
1302     // If the next token looks like a filename or the start of one,
1303     // assume it is and process it as such.
1304     if (!Tok.is(tok::angle_string_literal) && !Tok.is(tok::string_literal) &&
1305         !Tok.is(tok::less))
1306       return false;
1307   } else {
1308     // Save '(' location for possible missing ')' message.
1309     LParenLoc = Tok.getLocation();
1310 
1311     if (PP.getCurrentLexer()) {
1312       // Get the file name.
1313       PP.getCurrentLexer()->LexIncludeFilename(Tok);
1314     } else {
1315       // We're in a macro, so we can't use LexIncludeFilename; just
1316       // grab the next token.
1317       PP.Lex(Tok);
1318     }
1319   }
1320 
1321   // Reserve a buffer to get the spelling.
1322   SmallString<128> FilenameBuffer;
1323   StringRef Filename;
1324   SourceLocation EndLoc;
1325 
1326   switch (Tok.getKind()) {
1327   case tok::eod:
1328     // If the token kind is EOD, the error has already been diagnosed.
1329     return false;
1330 
1331   case tok::angle_string_literal:
1332   case tok::string_literal: {
1333     bool Invalid = false;
1334     Filename = PP.getSpelling(Tok, FilenameBuffer, &Invalid);
1335     if (Invalid)
1336       return false;
1337     break;
1338   }
1339 
1340   case tok::less:
1341     // This could be a <foo/bar.h> file coming from a macro expansion.  In this
1342     // case, glue the tokens together into FilenameBuffer and interpret those.
1343     FilenameBuffer.push_back('<');
1344     if (PP.ConcatenateIncludeName(FilenameBuffer, EndLoc)) {
1345       // Let the caller know a <eod> was found by changing the Token kind.
1346       Tok.setKind(tok::eod);
1347       return false;   // Found <eod> but no ">"?  Diagnostic already emitted.
1348     }
1349     Filename = FilenameBuffer;
1350     break;
1351   default:
1352     PP.Diag(Tok.getLocation(), diag::err_pp_expects_filename);
1353     return false;
1354   }
1355 
1356   SourceLocation FilenameLoc = Tok.getLocation();
1357 
1358   // Get ')'.
1359   PP.LexNonComment(Tok);
1360 
1361   // Ensure we have a trailing ).
1362   if (Tok.isNot(tok::r_paren)) {
1363     PP.Diag(PP.getLocForEndOfToken(FilenameLoc), diag::err_pp_expected_after)
1364         << II << tok::r_paren;
1365     PP.Diag(LParenLoc, diag::note_matching) << tok::l_paren;
1366     return false;
1367   }
1368 
1369   bool isAngled = PP.GetIncludeFilenameSpelling(Tok.getLocation(), Filename);
1370   // If GetIncludeFilenameSpelling set the start ptr to null, there was an
1371   // error.
1372   if (Filename.empty())
1373     return false;
1374 
1375   // Search include directories.
1376   const DirectoryLookup *CurDir;
1377   const FileEntry *File =
1378       PP.LookupFile(FilenameLoc, Filename, isAngled, LookupFrom, LookupFromFile,
1379                     CurDir, nullptr, nullptr, nullptr);
1380 
1381   // Get the result value.  A result of true means the file exists.
1382   return File != nullptr;
1383 }
1384 
1385 /// EvaluateHasInclude - Process a '__has_include("path")' expression.
1386 /// Returns true if successful.
EvaluateHasInclude(Token & Tok,IdentifierInfo * II,Preprocessor & PP)1387 static bool EvaluateHasInclude(Token &Tok, IdentifierInfo *II,
1388                                Preprocessor &PP) {
1389   return EvaluateHasIncludeCommon(Tok, II, PP, nullptr, nullptr);
1390 }
1391 
1392 /// EvaluateHasIncludeNext - Process '__has_include_next("path")' expression.
1393 /// Returns true if successful.
EvaluateHasIncludeNext(Token & Tok,IdentifierInfo * II,Preprocessor & PP)1394 static bool EvaluateHasIncludeNext(Token &Tok,
1395                                    IdentifierInfo *II, Preprocessor &PP) {
1396   // __has_include_next is like __has_include, except that we start
1397   // searching after the current found directory.  If we can't do this,
1398   // issue a diagnostic.
1399   // FIXME: Factor out duplication with
1400   // Preprocessor::HandleIncludeNextDirective.
1401   const DirectoryLookup *Lookup = PP.GetCurDirLookup();
1402   const FileEntry *LookupFromFile = nullptr;
1403   if (PP.isInPrimaryFile()) {
1404     Lookup = nullptr;
1405     PP.Diag(Tok, diag::pp_include_next_in_primary);
1406   } else if (PP.getCurrentSubmodule()) {
1407     // Start looking up in the directory *after* the one in which the current
1408     // file would be found, if any.
1409     assert(PP.getCurrentLexer() && "#include_next directive in macro?");
1410     LookupFromFile = PP.getCurrentLexer()->getFileEntry();
1411     Lookup = nullptr;
1412   } else if (!Lookup) {
1413     PP.Diag(Tok, diag::pp_include_next_absolute_path);
1414   } else {
1415     // Start looking up in the next directory.
1416     ++Lookup;
1417   }
1418 
1419   return EvaluateHasIncludeCommon(Tok, II, PP, Lookup, LookupFromFile);
1420 }
1421 
1422 /// \brief Process single-argument builtin feature-like macros that return
1423 /// integer values.
EvaluateFeatureLikeBuiltinMacro(llvm::raw_svector_ostream & OS,Token & Tok,IdentifierInfo * II,Preprocessor & PP,llvm::function_ref<int (Token & Tok,bool & HasLexedNextTok)> Op)1424 static void EvaluateFeatureLikeBuiltinMacro(llvm::raw_svector_ostream& OS,
1425                                             Token &Tok, IdentifierInfo *II,
1426                                             Preprocessor &PP,
1427                                             llvm::function_ref<
1428                                               int(Token &Tok,
1429                                                   bool &HasLexedNextTok)> Op) {
1430   // Parse the initial '('.
1431   PP.LexUnexpandedToken(Tok);
1432   if (Tok.isNot(tok::l_paren)) {
1433     PP.Diag(Tok.getLocation(), diag::err_pp_expected_after) << II
1434                                                             << tok::l_paren;
1435 
1436     // Provide a dummy '0' value on output stream to elide further errors.
1437     if (!Tok.isOneOf(tok::eof, tok::eod)) {
1438       OS << 0;
1439       Tok.setKind(tok::numeric_constant);
1440     }
1441     return;
1442   }
1443 
1444   unsigned ParenDepth = 1;
1445   SourceLocation LParenLoc = Tok.getLocation();
1446   llvm::Optional<int> Result;
1447 
1448   Token ResultTok;
1449   bool SuppressDiagnostic = false;
1450   while (true) {
1451     // Parse next token.
1452     PP.LexUnexpandedToken(Tok);
1453 
1454 already_lexed:
1455     switch (Tok.getKind()) {
1456       case tok::eof:
1457       case tok::eod:
1458         // Don't provide even a dummy value if the eod or eof marker is
1459         // reached.  Simply provide a diagnostic.
1460         PP.Diag(Tok.getLocation(), diag::err_unterm_macro_invoc);
1461         return;
1462 
1463       case tok::comma:
1464         if (!SuppressDiagnostic) {
1465           PP.Diag(Tok.getLocation(), diag::err_too_many_args_in_macro_invoc);
1466           SuppressDiagnostic = true;
1467         }
1468         continue;
1469 
1470       case tok::l_paren:
1471         ++ParenDepth;
1472         if (Result.hasValue())
1473           break;
1474         if (!SuppressDiagnostic) {
1475           PP.Diag(Tok.getLocation(), diag::err_pp_nested_paren) << II;
1476           SuppressDiagnostic = true;
1477         }
1478         continue;
1479 
1480       case tok::r_paren:
1481         if (--ParenDepth > 0)
1482           continue;
1483 
1484         // The last ')' has been reached; return the value if one found or
1485         // a diagnostic and a dummy value.
1486         if (Result.hasValue())
1487           OS << Result.getValue();
1488         else {
1489           OS << 0;
1490           if (!SuppressDiagnostic)
1491             PP.Diag(Tok.getLocation(), diag::err_too_few_args_in_macro_invoc);
1492         }
1493         Tok.setKind(tok::numeric_constant);
1494         return;
1495 
1496       default: {
1497         // Parse the macro argument, if one not found so far.
1498         if (Result.hasValue())
1499           break;
1500 
1501         bool HasLexedNextToken = false;
1502         Result = Op(Tok, HasLexedNextToken);
1503         ResultTok = Tok;
1504         if (HasLexedNextToken)
1505           goto already_lexed;
1506         continue;
1507       }
1508     }
1509 
1510     // Diagnose missing ')'.
1511     if (!SuppressDiagnostic) {
1512       if (auto Diag = PP.Diag(Tok.getLocation(), diag::err_pp_expected_after)) {
1513         if (IdentifierInfo *LastII = ResultTok.getIdentifierInfo())
1514           Diag << LastII;
1515         else
1516           Diag << ResultTok.getKind();
1517         Diag << tok::r_paren << ResultTok.getLocation();
1518       }
1519       PP.Diag(LParenLoc, diag::note_matching) << tok::l_paren;
1520       SuppressDiagnostic = true;
1521     }
1522   }
1523 }
1524 
1525 /// \brief Helper function to return the IdentifierInfo structure of a Token
1526 /// or generate a diagnostic if none available.
ExpectFeatureIdentifierInfo(Token & Tok,Preprocessor & PP,signed DiagID)1527 static IdentifierInfo *ExpectFeatureIdentifierInfo(Token &Tok,
1528                                                    Preprocessor &PP,
1529                                                    signed DiagID) {
1530   IdentifierInfo *II;
1531   if (!Tok.isAnnotation() && (II = Tok.getIdentifierInfo()))
1532     return II;
1533 
1534   PP.Diag(Tok.getLocation(), DiagID);
1535   return nullptr;
1536 }
1537 
1538 /// ExpandBuiltinMacro - If an identifier token is read that is to be expanded
1539 /// as a builtin macro, handle it and return the next token as 'Tok'.
ExpandBuiltinMacro(Token & Tok)1540 void Preprocessor::ExpandBuiltinMacro(Token &Tok) {
1541   // Figure out which token this is.
1542   IdentifierInfo *II = Tok.getIdentifierInfo();
1543   assert(II && "Can't be a macro without id info!");
1544 
1545   // If this is an _Pragma or Microsoft __pragma directive, expand it,
1546   // invoke the pragma handler, then lex the token after it.
1547   if (II == Ident_Pragma)
1548     return Handle_Pragma(Tok);
1549   else if (II == Ident__pragma) // in non-MS mode this is null
1550     return HandleMicrosoft__pragma(Tok);
1551 
1552   ++NumBuiltinMacroExpanded;
1553 
1554   SmallString<128> TmpBuffer;
1555   llvm::raw_svector_ostream OS(TmpBuffer);
1556 
1557   // Set up the return result.
1558   Tok.setIdentifierInfo(nullptr);
1559   Tok.clearFlag(Token::NeedsCleaning);
1560 
1561   if (II == Ident__LINE__) {
1562     // C99 6.10.8: "__LINE__: The presumed line number (within the current
1563     // source file) of the current source line (an integer constant)".  This can
1564     // be affected by #line.
1565     SourceLocation Loc = Tok.getLocation();
1566 
1567     // Advance to the location of the first _, this might not be the first byte
1568     // of the token if it starts with an escaped newline.
1569     Loc = AdvanceToTokenCharacter(Loc, 0);
1570 
1571     // One wrinkle here is that GCC expands __LINE__ to location of the *end* of
1572     // a macro expansion.  This doesn't matter for object-like macros, but
1573     // can matter for a function-like macro that expands to contain __LINE__.
1574     // Skip down through expansion points until we find a file loc for the
1575     // end of the expansion history.
1576     Loc = SourceMgr.getExpansionRange(Loc).second;
1577     PresumedLoc PLoc = SourceMgr.getPresumedLoc(Loc);
1578 
1579     // __LINE__ expands to a simple numeric value.
1580     OS << (PLoc.isValid()? PLoc.getLine() : 1);
1581     Tok.setKind(tok::numeric_constant);
1582   } else if (II == Ident__FILE__ || II == Ident__BASE_FILE__) {
1583     // C99 6.10.8: "__FILE__: The presumed name of the current source file (a
1584     // character string literal)". This can be affected by #line.
1585     PresumedLoc PLoc = SourceMgr.getPresumedLoc(Tok.getLocation());
1586 
1587     // __BASE_FILE__ is a GNU extension that returns the top of the presumed
1588     // #include stack instead of the current file.
1589     if (II == Ident__BASE_FILE__ && PLoc.isValid()) {
1590       SourceLocation NextLoc = PLoc.getIncludeLoc();
1591       while (NextLoc.isValid()) {
1592         PLoc = SourceMgr.getPresumedLoc(NextLoc);
1593         if (PLoc.isInvalid())
1594           break;
1595 
1596         NextLoc = PLoc.getIncludeLoc();
1597       }
1598     }
1599 
1600     // Escape this filename.  Turn '\' -> '\\' '"' -> '\"'
1601     SmallString<128> FN;
1602     if (PLoc.isValid()) {
1603       FN += PLoc.getFilename();
1604       Lexer::Stringify(FN);
1605       OS << '"' << FN << '"';
1606     }
1607     Tok.setKind(tok::string_literal);
1608   } else if (II == Ident__DATE__) {
1609     Diag(Tok.getLocation(), diag::warn_pp_date_time);
1610     if (!DATELoc.isValid())
1611       ComputeDATE_TIME(DATELoc, TIMELoc, *this);
1612     Tok.setKind(tok::string_literal);
1613     Tok.setLength(strlen("\"Mmm dd yyyy\""));
1614     Tok.setLocation(SourceMgr.createExpansionLoc(DATELoc, Tok.getLocation(),
1615                                                  Tok.getLocation(),
1616                                                  Tok.getLength()));
1617     return;
1618   } else if (II == Ident__TIME__) {
1619     Diag(Tok.getLocation(), diag::warn_pp_date_time);
1620     if (!TIMELoc.isValid())
1621       ComputeDATE_TIME(DATELoc, TIMELoc, *this);
1622     Tok.setKind(tok::string_literal);
1623     Tok.setLength(strlen("\"hh:mm:ss\""));
1624     Tok.setLocation(SourceMgr.createExpansionLoc(TIMELoc, Tok.getLocation(),
1625                                                  Tok.getLocation(),
1626                                                  Tok.getLength()));
1627     return;
1628   } else if (II == Ident__INCLUDE_LEVEL__) {
1629     // Compute the presumed include depth of this token.  This can be affected
1630     // by GNU line markers.
1631     unsigned Depth = 0;
1632 
1633     PresumedLoc PLoc = SourceMgr.getPresumedLoc(Tok.getLocation());
1634     if (PLoc.isValid()) {
1635       PLoc = SourceMgr.getPresumedLoc(PLoc.getIncludeLoc());
1636       for (; PLoc.isValid(); ++Depth)
1637         PLoc = SourceMgr.getPresumedLoc(PLoc.getIncludeLoc());
1638     }
1639 
1640     // __INCLUDE_LEVEL__ expands to a simple numeric value.
1641     OS << Depth;
1642     Tok.setKind(tok::numeric_constant);
1643   } else if (II == Ident__TIMESTAMP__) {
1644     Diag(Tok.getLocation(), diag::warn_pp_date_time);
1645     // MSVC, ICC, GCC, VisualAge C++ extension.  The generated string should be
1646     // of the form "Ddd Mmm dd hh::mm::ss yyyy", which is returned by asctime.
1647 
1648     // Get the file that we are lexing out of.  If we're currently lexing from
1649     // a macro, dig into the include stack.
1650     const FileEntry *CurFile = nullptr;
1651     PreprocessorLexer *TheLexer = getCurrentFileLexer();
1652 
1653     if (TheLexer)
1654       CurFile = SourceMgr.getFileEntryForID(TheLexer->getFileID());
1655 
1656     const char *Result;
1657     if (CurFile) {
1658       time_t TT = CurFile->getModificationTime();
1659       struct tm *TM = localtime(&TT);
1660       Result = asctime(TM);
1661     } else {
1662       Result = "??? ??? ?? ??:??:?? ????\n";
1663     }
1664     // Surround the string with " and strip the trailing newline.
1665     OS << '"' << StringRef(Result).drop_back() << '"';
1666     Tok.setKind(tok::string_literal);
1667   } else if (II == Ident__COUNTER__) {
1668     // __COUNTER__ expands to a simple numeric value.
1669     OS << CounterValue++;
1670     Tok.setKind(tok::numeric_constant);
1671   } else if (II == Ident__has_feature) {
1672     EvaluateFeatureLikeBuiltinMacro(OS, Tok, II, *this,
1673       [this](Token &Tok, bool &HasLexedNextToken) -> int {
1674         IdentifierInfo *II = ExpectFeatureIdentifierInfo(Tok, *this,
1675                                            diag::err_feature_check_malformed);
1676         return II && HasFeature(*this, II->getName());
1677       });
1678   } else if (II == Ident__has_extension) {
1679     EvaluateFeatureLikeBuiltinMacro(OS, Tok, II, *this,
1680       [this](Token &Tok, bool &HasLexedNextToken) -> int {
1681         IdentifierInfo *II = ExpectFeatureIdentifierInfo(Tok, *this,
1682                                            diag::err_feature_check_malformed);
1683         return II && HasExtension(*this, II->getName());
1684       });
1685   } else if (II == Ident__has_builtin) {
1686     EvaluateFeatureLikeBuiltinMacro(OS, Tok, II, *this,
1687       [this](Token &Tok, bool &HasLexedNextToken) -> int {
1688         IdentifierInfo *II = ExpectFeatureIdentifierInfo(Tok, *this,
1689                                            diag::err_feature_check_malformed);
1690         if (!II)
1691           return false;
1692         else if (II->getBuiltinID() != 0)
1693           return true;
1694         else {
1695           const LangOptions &LangOpts = getLangOpts();
1696           return llvm::StringSwitch<bool>(II->getName())
1697                       .Case("__make_integer_seq", LangOpts.CPlusPlus)
1698                       .Case("__type_pack_element", LangOpts.CPlusPlus)
1699                       .Default(false);
1700         }
1701       });
1702   } else if (II == Ident__is_identifier) {
1703     EvaluateFeatureLikeBuiltinMacro(OS, Tok, II, *this,
1704       [](Token &Tok, bool &HasLexedNextToken) -> int {
1705         return Tok.is(tok::identifier);
1706       });
1707   } else if (II == Ident__has_attribute) {
1708     EvaluateFeatureLikeBuiltinMacro(OS, Tok, II, *this,
1709       [this](Token &Tok, bool &HasLexedNextToken) -> int {
1710         IdentifierInfo *II = ExpectFeatureIdentifierInfo(Tok, *this,
1711                                            diag::err_feature_check_malformed);
1712         return II ? hasAttribute(AttrSyntax::GNU, nullptr, II,
1713                                  getTargetInfo(), getLangOpts()) : 0;
1714       });
1715   } else if (II == Ident__has_declspec) {
1716     EvaluateFeatureLikeBuiltinMacro(OS, Tok, II, *this,
1717       [this](Token &Tok, bool &HasLexedNextToken) -> int {
1718         IdentifierInfo *II = ExpectFeatureIdentifierInfo(Tok, *this,
1719                                            diag::err_feature_check_malformed);
1720         return II ? hasAttribute(AttrSyntax::Declspec, nullptr, II,
1721                                  getTargetInfo(), getLangOpts()) : 0;
1722       });
1723   } else if (II == Ident__has_cpp_attribute) {
1724     EvaluateFeatureLikeBuiltinMacro(OS, Tok, II, *this,
1725       [this](Token &Tok, bool &HasLexedNextToken) -> int {
1726         IdentifierInfo *ScopeII = nullptr;
1727         IdentifierInfo *II = ExpectFeatureIdentifierInfo(Tok, *this,
1728                                            diag::err_feature_check_malformed);
1729         if (!II)
1730           return false;
1731 
1732         // It is possible to receive a scope token.  Read the "::", if it is
1733         // available, and the subsequent identifier.
1734         LexUnexpandedToken(Tok);
1735         if (Tok.isNot(tok::coloncolon))
1736           HasLexedNextToken = true;
1737         else {
1738           ScopeII = II;
1739           LexUnexpandedToken(Tok);
1740           II = ExpectFeatureIdentifierInfo(Tok, *this,
1741                                            diag::err_feature_check_malformed);
1742         }
1743 
1744         return II ? hasAttribute(AttrSyntax::CXX, ScopeII, II,
1745                                  getTargetInfo(), getLangOpts()) : 0;
1746       });
1747   } else if (II == Ident__has_include ||
1748              II == Ident__has_include_next) {
1749     // The argument to these two builtins should be a parenthesized
1750     // file name string literal using angle brackets (<>) or
1751     // double-quotes ("").
1752     bool Value;
1753     if (II == Ident__has_include)
1754       Value = EvaluateHasInclude(Tok, II, *this);
1755     else
1756       Value = EvaluateHasIncludeNext(Tok, II, *this);
1757 
1758     if (Tok.isNot(tok::r_paren))
1759       return;
1760     OS << (int)Value;
1761     Tok.setKind(tok::numeric_constant);
1762   } else if (II == Ident__has_warning) {
1763     // The argument should be a parenthesized string literal.
1764     EvaluateFeatureLikeBuiltinMacro(OS, Tok, II, *this,
1765       [this](Token &Tok, bool &HasLexedNextToken) -> int {
1766         std::string WarningName;
1767         SourceLocation StrStartLoc = Tok.getLocation();
1768 
1769         HasLexedNextToken = Tok.is(tok::string_literal);
1770         if (!FinishLexStringLiteral(Tok, WarningName, "'__has_warning'",
1771                                     /*MacroExpansion=*/false))
1772           return false;
1773 
1774         // FIXME: Should we accept "-R..." flags here, or should that be
1775         // handled by a separate __has_remark?
1776         if (WarningName.size() < 3 || WarningName[0] != '-' ||
1777             WarningName[1] != 'W') {
1778           Diag(StrStartLoc, diag::warn_has_warning_invalid_option);
1779           return false;
1780         }
1781 
1782         // Finally, check if the warning flags maps to a diagnostic group.
1783         // We construct a SmallVector here to talk to getDiagnosticIDs().
1784         // Although we don't use the result, this isn't a hot path, and not
1785         // worth special casing.
1786         SmallVector<diag::kind, 10> Diags;
1787         return !getDiagnostics().getDiagnosticIDs()->
1788                 getDiagnosticsInGroup(diag::Flavor::WarningOrError,
1789                                       WarningName.substr(2), Diags);
1790       });
1791   } else if (II == Ident__building_module) {
1792     // The argument to this builtin should be an identifier. The
1793     // builtin evaluates to 1 when that identifier names the module we are
1794     // currently building.
1795     EvaluateFeatureLikeBuiltinMacro(OS, Tok, II, *this,
1796       [this](Token &Tok, bool &HasLexedNextToken) -> int {
1797         IdentifierInfo *II = ExpectFeatureIdentifierInfo(Tok, *this,
1798                                        diag::err_expected_id_building_module);
1799         return getLangOpts().CompilingModule && II &&
1800                (II->getName() == getLangOpts().CurrentModule);
1801       });
1802   } else if (II == Ident__MODULE__) {
1803     // The current module as an identifier.
1804     OS << getLangOpts().CurrentModule;
1805     IdentifierInfo *ModuleII = getIdentifierInfo(getLangOpts().CurrentModule);
1806     Tok.setIdentifierInfo(ModuleII);
1807     Tok.setKind(ModuleII->getTokenID());
1808   } else if (II == Ident__identifier) {
1809     SourceLocation Loc = Tok.getLocation();
1810 
1811     // We're expecting '__identifier' '(' identifier ')'. Try to recover
1812     // if the parens are missing.
1813     LexNonComment(Tok);
1814     if (Tok.isNot(tok::l_paren)) {
1815       // No '(', use end of last token.
1816       Diag(getLocForEndOfToken(Loc), diag::err_pp_expected_after)
1817         << II << tok::l_paren;
1818       // If the next token isn't valid as our argument, we can't recover.
1819       if (!Tok.isAnnotation() && Tok.getIdentifierInfo())
1820         Tok.setKind(tok::identifier);
1821       return;
1822     }
1823 
1824     SourceLocation LParenLoc = Tok.getLocation();
1825     LexNonComment(Tok);
1826 
1827     if (!Tok.isAnnotation() && Tok.getIdentifierInfo())
1828       Tok.setKind(tok::identifier);
1829     else {
1830       Diag(Tok.getLocation(), diag::err_pp_identifier_arg_not_identifier)
1831         << Tok.getKind();
1832       // Don't walk past anything that's not a real token.
1833       if (Tok.isOneOf(tok::eof, tok::eod) || Tok.isAnnotation())
1834         return;
1835     }
1836 
1837     // Discard the ')', preserving 'Tok' as our result.
1838     Token RParen;
1839     LexNonComment(RParen);
1840     if (RParen.isNot(tok::r_paren)) {
1841       Diag(getLocForEndOfToken(Tok.getLocation()), diag::err_pp_expected_after)
1842         << Tok.getKind() << tok::r_paren;
1843       Diag(LParenLoc, diag::note_matching) << tok::l_paren;
1844     }
1845     return;
1846   } else {
1847     llvm_unreachable("Unknown identifier!");
1848   }
1849   CreateString(OS.str(), Tok, Tok.getLocation(), Tok.getLocation());
1850 }
1851 
markMacroAsUsed(MacroInfo * MI)1852 void Preprocessor::markMacroAsUsed(MacroInfo *MI) {
1853   // If the 'used' status changed, and the macro requires 'unused' warning,
1854   // remove its SourceLocation from the warn-for-unused-macro locations.
1855   if (MI->isWarnIfUnused() && !MI->isUsed())
1856     WarnUnusedMacroLocs.erase(MI->getDefinitionLoc());
1857   MI->setIsUsed(true);
1858 }
1859