Pragma.cpp revision f45b646244705410866d62f1d8bf017a047ed662
1//===--- Pragma.cpp - Pragma registration and handling --------------------===//
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 PragmaHandler/PragmaTable interfaces and implements
11// pragma related methods of the Preprocessor class.
12//
13//===----------------------------------------------------------------------===//
14
15#include "clang/Lex/Pragma.h"
16#include "clang/Lex/HeaderSearch.h"
17#include "clang/Lex/LiteralSupport.h"
18#include "clang/Lex/Preprocessor.h"
19#include "clang/Lex/LexDiagnostic.h"
20#include "clang/Basic/FileManager.h"
21#include "clang/Basic/SourceManager.h"
22#include <algorithm>
23using namespace clang;
24
25// Out-of-line destructor to provide a home for the class.
26PragmaHandler::~PragmaHandler() {
27}
28
29//===----------------------------------------------------------------------===//
30// PragmaNamespace Implementation.
31//===----------------------------------------------------------------------===//
32
33
34PragmaNamespace::~PragmaNamespace() {
35  for (unsigned i = 0, e = Handlers.size(); i != e; ++i)
36    delete Handlers[i];
37}
38
39/// FindHandler - Check to see if there is already a handler for the
40/// specified name.  If not, return the handler for the null identifier if it
41/// exists, otherwise return null.  If IgnoreNull is true (the default) then
42/// the null handler isn't returned on failure to match.
43PragmaHandler *PragmaNamespace::FindHandler(const IdentifierInfo *Name,
44                                            bool IgnoreNull) const {
45  PragmaHandler *NullHandler = 0;
46  for (unsigned i = 0, e = Handlers.size(); i != e; ++i) {
47    if (Handlers[i]->getName() == Name)
48      return Handlers[i];
49
50    if (Handlers[i]->getName() == 0)
51      NullHandler = Handlers[i];
52  }
53  return IgnoreNull ? 0 : NullHandler;
54}
55
56void PragmaNamespace::RemovePragmaHandler(PragmaHandler *Handler) {
57  for (unsigned i = 0, e = Handlers.size(); i != e; ++i) {
58    if (Handlers[i] == Handler) {
59      Handlers[i] = Handlers.back();
60      Handlers.pop_back();
61      return;
62    }
63  }
64  assert(0 && "Handler not registered in this namespace");
65}
66
67void PragmaNamespace::HandlePragma(Preprocessor &PP, Token &Tok) {
68  // Read the 'namespace' that the directive is in, e.g. STDC.  Do not macro
69  // expand it, the user can have a STDC #define, that should not affect this.
70  PP.LexUnexpandedToken(Tok);
71
72  // Get the handler for this token.  If there is no handler, ignore the pragma.
73  PragmaHandler *Handler = FindHandler(Tok.getIdentifierInfo(), false);
74  if (Handler == 0) {
75    PP.Diag(Tok, diag::warn_pragma_ignored);
76    return;
77  }
78
79  // Otherwise, pass it down.
80  Handler->HandlePragma(PP, Tok);
81}
82
83//===----------------------------------------------------------------------===//
84// Preprocessor Pragma Directive Handling.
85//===----------------------------------------------------------------------===//
86
87/// HandlePragmaDirective - The "#pragma" directive has been parsed.  Lex the
88/// rest of the pragma, passing it to the registered pragma handlers.
89void Preprocessor::HandlePragmaDirective() {
90  ++NumPragma;
91
92  // Invoke the first level of pragma handlers which reads the namespace id.
93  Token Tok;
94  PragmaHandlers->HandlePragma(*this, Tok);
95
96  // If the pragma handler didn't read the rest of the line, consume it now.
97  if (CurPPLexer && CurPPLexer->ParsingPreprocessorDirective)
98    DiscardUntilEndOfDirective();
99}
100
101/// Handle_Pragma - Read a _Pragma directive, slice it up, process it, then
102/// return the first token after the directive.  The _Pragma token has just
103/// been read into 'Tok'.
104void Preprocessor::Handle_Pragma(Token &Tok) {
105  // Remember the pragma token location.
106  SourceLocation PragmaLoc = Tok.getLocation();
107
108  // Read the '('.
109  Lex(Tok);
110  if (Tok.isNot(tok::l_paren)) {
111    Diag(PragmaLoc, diag::err__Pragma_malformed);
112    return;
113  }
114
115  // Read the '"..."'.
116  Lex(Tok);
117  if (Tok.isNot(tok::string_literal) && Tok.isNot(tok::wide_string_literal)) {
118    Diag(PragmaLoc, diag::err__Pragma_malformed);
119    return;
120  }
121
122  // Remember the string.
123  std::string StrVal = getSpelling(Tok);
124
125  // Read the ')'.
126  Lex(Tok);
127  if (Tok.isNot(tok::r_paren)) {
128    Diag(PragmaLoc, diag::err__Pragma_malformed);
129    return;
130  }
131
132  SourceLocation RParenLoc = Tok.getLocation();
133
134  // The _Pragma is lexically sound.  Destringize according to C99 6.10.9.1:
135  // "The string literal is destringized by deleting the L prefix, if present,
136  // deleting the leading and trailing double-quotes, replacing each escape
137  // sequence \" by a double-quote, and replacing each escape sequence \\ by a
138  // single backslash."
139  if (StrVal[0] == 'L')  // Remove L prefix.
140    StrVal.erase(StrVal.begin());
141  assert(StrVal[0] == '"' && StrVal[StrVal.size()-1] == '"' &&
142         "Invalid string token!");
143
144  // Remove the front quote, replacing it with a space, so that the pragma
145  // contents appear to have a space before them.
146  StrVal[0] = ' ';
147
148  // Replace the terminating quote with a \n.
149  StrVal[StrVal.size()-1] = '\n';
150
151  // Remove escaped quotes and escapes.
152  for (unsigned i = 0, e = StrVal.size(); i != e-1; ++i) {
153    if (StrVal[i] == '\\' &&
154        (StrVal[i+1] == '\\' || StrVal[i+1] == '"')) {
155      // \\ -> '\' and \" -> '"'.
156      StrVal.erase(StrVal.begin()+i);
157      --e;
158    }
159  }
160
161  // Plop the string (including the newline and trailing null) into a buffer
162  // where we can lex it.
163  Token TmpTok;
164  TmpTok.startToken();
165  CreateString(&StrVal[0], StrVal.size(), TmpTok);
166  SourceLocation TokLoc = TmpTok.getLocation();
167
168  // Make and enter a lexer object so that we lex and expand the tokens just
169  // like any others.
170  Lexer *TL = Lexer::Create_PragmaLexer(TokLoc, PragmaLoc, RParenLoc,
171                                        StrVal.size(), *this);
172
173  EnterSourceFileWithLexer(TL, 0);
174
175  // With everything set up, lex this as a #pragma directive.
176  HandlePragmaDirective();
177
178  // Finally, return whatever came after the pragma directive.
179  return Lex(Tok);
180}
181
182
183
184/// HandlePragmaOnce - Handle #pragma once.  OnceTok is the 'once'.
185///
186void Preprocessor::HandlePragmaOnce(Token &OnceTok) {
187  if (isInPrimaryFile()) {
188    Diag(OnceTok, diag::pp_pragma_once_in_main_file);
189    return;
190  }
191
192  // Get the current file lexer we're looking at.  Ignore _Pragma 'files' etc.
193  // Mark the file as a once-only file now.
194  HeaderInfo.MarkFileIncludeOnce(getCurrentFileLexer()->getFileEntry());
195}
196
197void Preprocessor::HandlePragmaMark() {
198  assert(CurPPLexer && "No current lexer?");
199  if (CurLexer)
200    CurLexer->ReadToEndOfLine();
201  else
202    CurPTHLexer->DiscardToEndOfLine();
203}
204
205
206/// HandlePragmaPoison - Handle #pragma GCC poison.  PoisonTok is the 'poison'.
207///
208void Preprocessor::HandlePragmaPoison(Token &PoisonTok) {
209  Token Tok;
210
211  while (1) {
212    // Read the next token to poison.  While doing this, pretend that we are
213    // skipping while reading the identifier to poison.
214    // This avoids errors on code like:
215    //   #pragma GCC poison X
216    //   #pragma GCC poison X
217    if (CurPPLexer) CurPPLexer->LexingRawMode = true;
218    LexUnexpandedToken(Tok);
219    if (CurPPLexer) CurPPLexer->LexingRawMode = false;
220
221    // If we reached the end of line, we're done.
222    if (Tok.is(tok::eom)) return;
223
224    // Can only poison identifiers.
225    if (Tok.isNot(tok::identifier)) {
226      Diag(Tok, diag::err_pp_invalid_poison);
227      return;
228    }
229
230    // Look up the identifier info for the token.  We disabled identifier lookup
231    // by saying we're skipping contents, so we need to do this manually.
232    IdentifierInfo *II = LookUpIdentifierInfo(Tok);
233
234    // Already poisoned.
235    if (II->isPoisoned()) continue;
236
237    // If this is a macro identifier, emit a warning.
238    if (II->hasMacroDefinition())
239      Diag(Tok, diag::pp_poisoning_existing_macro);
240
241    // Finally, poison it!
242    II->setIsPoisoned();
243  }
244}
245
246/// HandlePragmaSystemHeader - Implement #pragma GCC system_header.  We know
247/// that the whole directive has been parsed.
248void Preprocessor::HandlePragmaSystemHeader(Token &SysHeaderTok) {
249  if (isInPrimaryFile()) {
250    Diag(SysHeaderTok, diag::pp_pragma_sysheader_in_main_file);
251    return;
252  }
253
254  // Get the current file lexer we're looking at.  Ignore _Pragma 'files' etc.
255  PreprocessorLexer *TheLexer = getCurrentFileLexer();
256
257  // Mark the file as a system header.
258  HeaderInfo.MarkFileSystemHeader(TheLexer->getFileEntry());
259
260
261  PresumedLoc PLoc = SourceMgr.getPresumedLoc(SysHeaderTok.getLocation());
262  unsigned FilenameLen = strlen(PLoc.getFilename());
263  unsigned FilenameID = SourceMgr.getLineTableFilenameID(PLoc.getFilename(),
264                                                         FilenameLen);
265
266  // Emit a line marker.  This will change any source locations from this point
267  // forward to realize they are in a system header.
268  // Create a line note with this information.
269  SourceMgr.AddLineNote(SysHeaderTok.getLocation(), PLoc.getLine(), FilenameID,
270                        false, false, true, false);
271
272  // Notify the client, if desired, that we are in a new source file.
273  if (Callbacks)
274    Callbacks->FileChanged(SysHeaderTok.getLocation(),
275                           PPCallbacks::SystemHeaderPragma, SrcMgr::C_System);
276}
277
278/// HandlePragmaDependency - Handle #pragma GCC dependency "foo" blah.
279///
280void Preprocessor::HandlePragmaDependency(Token &DependencyTok) {
281  Token FilenameTok;
282  CurPPLexer->LexIncludeFilename(FilenameTok);
283
284  // If the token kind is EOM, the error has already been diagnosed.
285  if (FilenameTok.is(tok::eom))
286    return;
287
288  // Reserve a buffer to get the spelling.
289  llvm::SmallString<128> FilenameBuffer;
290  FilenameBuffer.resize(FilenameTok.getLength());
291
292  const char *FilenameStart = &FilenameBuffer[0];
293  unsigned Len = getSpelling(FilenameTok, FilenameStart);
294  llvm::StringRef Filename(FilenameStart, Len);
295  bool isAngled =
296    GetIncludeFilenameSpelling(FilenameTok.getLocation(), Filename);
297  // If GetIncludeFilenameSpelling set the start ptr to null, there was an
298  // error.
299  if (Filename.empty())
300    return;
301
302  // Search include directories for this file.
303  const DirectoryLookup *CurDir;
304  const FileEntry *File = LookupFile(Filename, isAngled, 0, CurDir);
305  if (File == 0) {
306    Diag(FilenameTok, diag::err_pp_file_not_found) << Filename;
307    return;
308  }
309
310  const FileEntry *CurFile = getCurrentFileLexer()->getFileEntry();
311
312  // If this file is older than the file it depends on, emit a diagnostic.
313  if (CurFile && CurFile->getModificationTime() < File->getModificationTime()) {
314    // Lex tokens at the end of the message and include them in the message.
315    std::string Message;
316    Lex(DependencyTok);
317    while (DependencyTok.isNot(tok::eom)) {
318      Message += getSpelling(DependencyTok) + " ";
319      Lex(DependencyTok);
320    }
321
322    Message.erase(Message.end()-1);
323    Diag(FilenameTok, diag::pp_out_of_date_dependency) << Message;
324  }
325}
326
327/// HandlePragmaComment - Handle the microsoft #pragma comment extension.  The
328/// syntax is:
329///   #pragma comment(linker, "foo")
330/// 'linker' is one of five identifiers: compiler, exestr, lib, linker, user.
331/// "foo" is a string, which is fully macro expanded, and permits string
332/// concatenation, embedded escape characters etc.  See MSDN for more details.
333void Preprocessor::HandlePragmaComment(Token &Tok) {
334  SourceLocation CommentLoc = Tok.getLocation();
335  Lex(Tok);
336  if (Tok.isNot(tok::l_paren)) {
337    Diag(CommentLoc, diag::err_pragma_comment_malformed);
338    return;
339  }
340
341  // Read the identifier.
342  Lex(Tok);
343  if (Tok.isNot(tok::identifier)) {
344    Diag(CommentLoc, diag::err_pragma_comment_malformed);
345    return;
346  }
347
348  // Verify that this is one of the 5 whitelisted options.
349  // FIXME: warn that 'exestr' is deprecated.
350  const IdentifierInfo *II = Tok.getIdentifierInfo();
351  if (!II->isStr("compiler") && !II->isStr("exestr") && !II->isStr("lib") &&
352      !II->isStr("linker") && !II->isStr("user")) {
353    Diag(Tok.getLocation(), diag::err_pragma_comment_unknown_kind);
354    return;
355  }
356
357  // Read the optional string if present.
358  Lex(Tok);
359  std::string ArgumentString;
360  if (Tok.is(tok::comma)) {
361    Lex(Tok); // eat the comma.
362
363    // We need at least one string.
364    if (Tok.isNot(tok::string_literal)) {
365      Diag(Tok.getLocation(), diag::err_pragma_comment_malformed);
366      return;
367    }
368
369    // String concatenation allows multiple strings, which can even come from
370    // macro expansion.
371    // "foo " "bar" "Baz"
372    llvm::SmallVector<Token, 4> StrToks;
373    while (Tok.is(tok::string_literal)) {
374      StrToks.push_back(Tok);
375      Lex(Tok);
376    }
377
378    // Concatenate and parse the strings.
379    StringLiteralParser Literal(&StrToks[0], StrToks.size(), *this);
380    assert(!Literal.AnyWide && "Didn't allow wide strings in");
381    if (Literal.hadError)
382      return;
383    if (Literal.Pascal) {
384      Diag(StrToks[0].getLocation(), diag::err_pragma_comment_malformed);
385      return;
386    }
387
388    ArgumentString = std::string(Literal.GetString(),
389                                 Literal.GetString()+Literal.GetStringLength());
390  }
391
392  // FIXME: If the kind is "compiler" warn if the string is present (it is
393  // ignored).
394  // FIXME: 'lib' requires a comment string.
395  // FIXME: 'linker' requires a comment string, and has a specific list of
396  // things that are allowable.
397
398  if (Tok.isNot(tok::r_paren)) {
399    Diag(Tok.getLocation(), diag::err_pragma_comment_malformed);
400    return;
401  }
402  Lex(Tok);  // eat the r_paren.
403
404  if (Tok.isNot(tok::eom)) {
405    Diag(Tok.getLocation(), diag::err_pragma_comment_malformed);
406    return;
407  }
408
409  // If the pragma is lexically sound, notify any interested PPCallbacks.
410  if (Callbacks)
411    Callbacks->PragmaComment(CommentLoc, II, ArgumentString);
412}
413
414
415
416
417/// AddPragmaHandler - Add the specified pragma handler to the preprocessor.
418/// If 'Namespace' is non-null, then it is a token required to exist on the
419/// pragma line before the pragma string starts, e.g. "STDC" or "GCC".
420void Preprocessor::AddPragmaHandler(const char *Namespace,
421                                    PragmaHandler *Handler) {
422  PragmaNamespace *InsertNS = PragmaHandlers;
423
424  // If this is specified to be in a namespace, step down into it.
425  if (Namespace) {
426    IdentifierInfo *NSID = getIdentifierInfo(Namespace);
427
428    // If there is already a pragma handler with the name of this namespace,
429    // we either have an error (directive with the same name as a namespace) or
430    // we already have the namespace to insert into.
431    if (PragmaHandler *Existing = PragmaHandlers->FindHandler(NSID)) {
432      InsertNS = Existing->getIfNamespace();
433      assert(InsertNS != 0 && "Cannot have a pragma namespace and pragma"
434             " handler with the same name!");
435    } else {
436      // Otherwise, this namespace doesn't exist yet, create and insert the
437      // handler for it.
438      InsertNS = new PragmaNamespace(NSID);
439      PragmaHandlers->AddPragma(InsertNS);
440    }
441  }
442
443  // Check to make sure we don't already have a pragma for this identifier.
444  assert(!InsertNS->FindHandler(Handler->getName()) &&
445         "Pragma handler already exists for this identifier!");
446  InsertNS->AddPragma(Handler);
447}
448
449/// RemovePragmaHandler - Remove the specific pragma handler from the
450/// preprocessor. If \arg Namespace is non-null, then it should be the
451/// namespace that \arg Handler was added to. It is an error to remove
452/// a handler that has not been registered.
453void Preprocessor::RemovePragmaHandler(const char *Namespace,
454                                       PragmaHandler *Handler) {
455  PragmaNamespace *NS = PragmaHandlers;
456
457  // If this is specified to be in a namespace, step down into it.
458  if (Namespace) {
459    IdentifierInfo *NSID = getIdentifierInfo(Namespace);
460    PragmaHandler *Existing = PragmaHandlers->FindHandler(NSID);
461    assert(Existing && "Namespace containing handler does not exist!");
462
463    NS = Existing->getIfNamespace();
464    assert(NS && "Invalid namespace, registered as a regular pragma handler!");
465  }
466
467  NS->RemovePragmaHandler(Handler);
468
469  // If this is a non-default namespace and it is now empty, remove
470  // it.
471  if (NS != PragmaHandlers && NS->IsEmpty())
472    PragmaHandlers->RemovePragmaHandler(NS);
473}
474
475namespace {
476/// PragmaOnceHandler - "#pragma once" marks the file as atomically included.
477struct PragmaOnceHandler : public PragmaHandler {
478  PragmaOnceHandler(const IdentifierInfo *OnceID) : PragmaHandler(OnceID) {}
479  virtual void HandlePragma(Preprocessor &PP, Token &OnceTok) {
480    PP.CheckEndOfDirective("pragma once");
481    PP.HandlePragmaOnce(OnceTok);
482  }
483};
484
485/// PragmaMarkHandler - "#pragma mark ..." is ignored by the compiler, and the
486/// rest of the line is not lexed.
487struct PragmaMarkHandler : public PragmaHandler {
488  PragmaMarkHandler(const IdentifierInfo *MarkID) : PragmaHandler(MarkID) {}
489  virtual void HandlePragma(Preprocessor &PP, Token &MarkTok) {
490    PP.HandlePragmaMark();
491  }
492};
493
494/// PragmaPoisonHandler - "#pragma poison x" marks x as not usable.
495struct PragmaPoisonHandler : public PragmaHandler {
496  PragmaPoisonHandler(const IdentifierInfo *ID) : PragmaHandler(ID) {}
497  virtual void HandlePragma(Preprocessor &PP, Token &PoisonTok) {
498    PP.HandlePragmaPoison(PoisonTok);
499  }
500};
501
502/// PragmaSystemHeaderHandler - "#pragma system_header" marks the current file
503/// as a system header, which silences warnings in it.
504struct PragmaSystemHeaderHandler : public PragmaHandler {
505  PragmaSystemHeaderHandler(const IdentifierInfo *ID) : PragmaHandler(ID) {}
506  virtual void HandlePragma(Preprocessor &PP, Token &SHToken) {
507    PP.HandlePragmaSystemHeader(SHToken);
508    PP.CheckEndOfDirective("pragma");
509  }
510};
511struct PragmaDependencyHandler : public PragmaHandler {
512  PragmaDependencyHandler(const IdentifierInfo *ID) : PragmaHandler(ID) {}
513  virtual void HandlePragma(Preprocessor &PP, Token &DepToken) {
514    PP.HandlePragmaDependency(DepToken);
515  }
516};
517
518/// PragmaDiagnosticHandler - e.g. '#pragma GCC diagnostic ignored "-Wformat"'
519/// Since clang's diagnostic supports extended functionality beyond GCC's
520/// the constructor takes a clangMode flag to tell it whether or not to allow
521/// clang's extended functionality, or whether to reject it.
522struct PragmaDiagnosticHandler : public PragmaHandler {
523private:
524  const bool ClangMode;
525public:
526  PragmaDiagnosticHandler(const IdentifierInfo *ID,
527                          const bool clangMode) : PragmaHandler(ID),
528                                                  ClangMode(clangMode) {}
529  virtual void HandlePragma(Preprocessor &PP, Token &DiagToken) {
530    Token Tok;
531    PP.LexUnexpandedToken(Tok);
532    if (Tok.isNot(tok::identifier)) {
533      unsigned Diag = ClangMode ? diag::warn_pragma_diagnostic_clang_invalid
534                                 : diag::warn_pragma_diagnostic_gcc_invalid;
535      PP.Diag(Tok, Diag);
536      return;
537    }
538    IdentifierInfo *II = Tok.getIdentifierInfo();
539
540    diag::Mapping Map;
541    if (II->isStr("warning"))
542      Map = diag::MAP_WARNING;
543    else if (II->isStr("error"))
544      Map = diag::MAP_ERROR;
545    else if (II->isStr("ignored"))
546      Map = diag::MAP_IGNORE;
547    else if (II->isStr("fatal"))
548      Map = diag::MAP_FATAL;
549    else if (ClangMode) {
550      if (II->isStr("pop")) {
551        if (!PP.getDiagnostics().popMappings())
552          PP.Diag(Tok, diag::warn_pragma_diagnostic_clang_cannot_ppp);
553        return;
554      }
555
556      if (II->isStr("push")) {
557        PP.getDiagnostics().pushMappings();
558        return;
559      }
560
561      PP.Diag(Tok, diag::warn_pragma_diagnostic_clang_invalid);
562      return;
563    } else {
564      PP.Diag(Tok, diag::warn_pragma_diagnostic_gcc_invalid);
565      return;
566    }
567
568    PP.LexUnexpandedToken(Tok);
569
570    // We need at least one string.
571    if (Tok.isNot(tok::string_literal)) {
572      PP.Diag(Tok.getLocation(), diag::warn_pragma_diagnostic_invalid_token);
573      return;
574    }
575
576    // String concatenation allows multiple strings, which can even come from
577    // macro expansion.
578    // "foo " "bar" "Baz"
579    llvm::SmallVector<Token, 4> StrToks;
580    while (Tok.is(tok::string_literal)) {
581      StrToks.push_back(Tok);
582      PP.LexUnexpandedToken(Tok);
583    }
584
585    if (Tok.isNot(tok::eom)) {
586      PP.Diag(Tok.getLocation(), diag::warn_pragma_diagnostic_invalid_token);
587      return;
588    }
589
590    // Concatenate and parse the strings.
591    StringLiteralParser Literal(&StrToks[0], StrToks.size(), PP);
592    assert(!Literal.AnyWide && "Didn't allow wide strings in");
593    if (Literal.hadError)
594      return;
595    if (Literal.Pascal) {
596      unsigned Diag = ClangMode ? diag::warn_pragma_diagnostic_clang_invalid
597                                 : diag::warn_pragma_diagnostic_gcc_invalid;
598      PP.Diag(Tok, Diag);
599      return;
600    }
601
602    std::string WarningName(Literal.GetString(),
603                            Literal.GetString()+Literal.GetStringLength());
604
605    if (WarningName.size() < 3 || WarningName[0] != '-' ||
606        WarningName[1] != 'W') {
607      PP.Diag(StrToks[0].getLocation(),
608              diag::warn_pragma_diagnostic_invalid_option);
609      return;
610    }
611
612    if (PP.getDiagnostics().setDiagnosticGroupMapping(WarningName.c_str()+2,
613                                                      Map))
614      PP.Diag(StrToks[0].getLocation(),
615              diag::warn_pragma_diagnostic_unknown_warning) << WarningName;
616  }
617};
618
619/// PragmaCommentHandler - "#pragma comment ...".
620struct PragmaCommentHandler : public PragmaHandler {
621  PragmaCommentHandler(const IdentifierInfo *ID) : PragmaHandler(ID) {}
622  virtual void HandlePragma(Preprocessor &PP, Token &CommentTok) {
623    PP.HandlePragmaComment(CommentTok);
624  }
625};
626
627// Pragma STDC implementations.
628
629enum STDCSetting {
630  STDC_ON, STDC_OFF, STDC_DEFAULT, STDC_INVALID
631};
632
633static STDCSetting LexOnOffSwitch(Preprocessor &PP) {
634  Token Tok;
635  PP.LexUnexpandedToken(Tok);
636
637  if (Tok.isNot(tok::identifier)) {
638    PP.Diag(Tok, diag::ext_stdc_pragma_syntax);
639    return STDC_INVALID;
640  }
641  IdentifierInfo *II = Tok.getIdentifierInfo();
642  STDCSetting Result;
643  if (II->isStr("ON"))
644    Result = STDC_ON;
645  else if (II->isStr("OFF"))
646    Result = STDC_OFF;
647  else if (II->isStr("DEFAULT"))
648    Result = STDC_DEFAULT;
649  else {
650    PP.Diag(Tok, diag::ext_stdc_pragma_syntax);
651    return STDC_INVALID;
652  }
653
654  // Verify that this is followed by EOM.
655  PP.LexUnexpandedToken(Tok);
656  if (Tok.isNot(tok::eom))
657    PP.Diag(Tok, diag::ext_stdc_pragma_syntax_eom);
658  return Result;
659}
660
661/// PragmaSTDC_FP_CONTRACTHandler - "#pragma STDC FP_CONTRACT ...".
662struct PragmaSTDC_FP_CONTRACTHandler : public PragmaHandler {
663  PragmaSTDC_FP_CONTRACTHandler(const IdentifierInfo *ID) : PragmaHandler(ID) {}
664  virtual void HandlePragma(Preprocessor &PP, Token &Tok) {
665    // We just ignore the setting of FP_CONTRACT. Since we don't do contractions
666    // at all, our default is OFF and setting it to ON is an optimization hint
667    // we can safely ignore.  When we support -ffma or something, we would need
668    // to diagnose that we are ignoring FMA.
669    LexOnOffSwitch(PP);
670  }
671};
672
673/// PragmaSTDC_FENV_ACCESSHandler - "#pragma STDC FENV_ACCESS ...".
674struct PragmaSTDC_FENV_ACCESSHandler : public PragmaHandler {
675  PragmaSTDC_FENV_ACCESSHandler(const IdentifierInfo *ID) : PragmaHandler(ID) {}
676  virtual void HandlePragma(Preprocessor &PP, Token &Tok) {
677    if (LexOnOffSwitch(PP) == STDC_ON)
678      PP.Diag(Tok, diag::warn_stdc_fenv_access_not_supported);
679  }
680};
681
682/// PragmaSTDC_CX_LIMITED_RANGEHandler - "#pragma STDC CX_LIMITED_RANGE ...".
683struct PragmaSTDC_CX_LIMITED_RANGEHandler : public PragmaHandler {
684  PragmaSTDC_CX_LIMITED_RANGEHandler(const IdentifierInfo *ID)
685    : PragmaHandler(ID) {}
686  virtual void HandlePragma(Preprocessor &PP, Token &Tok) {
687    LexOnOffSwitch(PP);
688  }
689};
690
691/// PragmaSTDC_UnknownHandler - "#pragma STDC ...".
692struct PragmaSTDC_UnknownHandler : public PragmaHandler {
693  PragmaSTDC_UnknownHandler() : PragmaHandler(0) {}
694  virtual void HandlePragma(Preprocessor &PP, Token &UnknownTok) {
695    // C99 6.10.6p2, unknown forms are not allowed.
696    PP.Diag(UnknownTok, diag::ext_stdc_pragma_ignored);
697  }
698};
699
700}  // end anonymous namespace
701
702
703/// RegisterBuiltinPragmas - Install the standard preprocessor pragmas:
704/// #pragma GCC poison/system_header/dependency and #pragma once.
705void Preprocessor::RegisterBuiltinPragmas() {
706  AddPragmaHandler(0, new PragmaOnceHandler(getIdentifierInfo("once")));
707  AddPragmaHandler(0, new PragmaMarkHandler(getIdentifierInfo("mark")));
708
709  // #pragma GCC ...
710  AddPragmaHandler("GCC", new PragmaPoisonHandler(getIdentifierInfo("poison")));
711  AddPragmaHandler("GCC", new PragmaSystemHeaderHandler(
712                                          getIdentifierInfo("system_header")));
713  AddPragmaHandler("GCC", new PragmaDependencyHandler(
714                                          getIdentifierInfo("dependency")));
715  AddPragmaHandler("GCC", new PragmaDiagnosticHandler(
716                                              getIdentifierInfo("diagnostic"),
717                                              false));
718  // #pragma clang ...
719  AddPragmaHandler("clang", new PragmaPoisonHandler(
720                                          getIdentifierInfo("poison")));
721  AddPragmaHandler("clang", new PragmaSystemHeaderHandler(
722                                          getIdentifierInfo("system_header")));
723  AddPragmaHandler("clang", new PragmaDependencyHandler(
724                                          getIdentifierInfo("dependency")));
725  AddPragmaHandler("clang", new PragmaDiagnosticHandler(
726                                          getIdentifierInfo("diagnostic"),
727                                          true));
728
729  AddPragmaHandler("STDC", new PragmaSTDC_FP_CONTRACTHandler(
730                                             getIdentifierInfo("FP_CONTRACT")));
731  AddPragmaHandler("STDC", new PragmaSTDC_FENV_ACCESSHandler(
732                                             getIdentifierInfo("FENV_ACCESS")));
733  AddPragmaHandler("STDC", new PragmaSTDC_CX_LIMITED_RANGEHandler(
734                                        getIdentifierInfo("CX_LIMITED_RANGE")));
735  AddPragmaHandler("STDC", new PragmaSTDC_UnknownHandler());
736
737  // MS extensions.
738  if (Features.Microsoft)
739    AddPragmaHandler(0, new PragmaCommentHandler(getIdentifierInfo("comment")));
740}
741