InitPreprocessor.cpp revision 4ae4c919205307c6e98e6c920aa55019040cbe77 
1//===--- InitPreprocessor.cpp - PP initialization code. ---------*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file implements the clang::InitializePreprocessor function.
11//
12//===----------------------------------------------------------------------===//
13
14#include "clang/Basic/Version.h"
15#include "clang/Frontend/Utils.h"
16#include "clang/Basic/MacroBuilder.h"
17#include "clang/Basic/TargetInfo.h"
18#include "clang/Frontend/FrontendDiagnostic.h"
19#include "clang/Frontend/FrontendOptions.h"
20#include "clang/Frontend/PreprocessorOptions.h"
21#include "clang/Lex/Preprocessor.h"
22#include "clang/Basic/FileManager.h"
23#include "clang/Basic/SourceManager.h"
24#include "llvm/ADT/APFloat.h"
25#include "llvm/Support/MemoryBuffer.h"
26#include "llvm/System/Path.h"
27using namespace clang;
28
29// Append a #define line to Buf for Macro.  Macro should be of the form XXX,
30// in which case we emit "#define XXX 1" or "XXX=Y z W" in which case we emit
31// "#define XXX Y z W".  To get a #define with no value, use "XXX=".
32static void DefineBuiltinMacro(MacroBuilder &Builder, llvm::StringRef Macro,
33                               Diagnostic &Diags) {
34  std::pair<llvm::StringRef, llvm::StringRef> MacroPair = Macro.split('=');
35  llvm::StringRef MacroName = MacroPair.first;
36  llvm::StringRef MacroBody = MacroPair.second;
37  if (MacroName.size() != Macro.size()) {
38    // Per GCC -D semantics, the macro ends at \n if it exists.
39    llvm::StringRef::size_type End = MacroBody.find_first_of("\n\r");
40    if (End != llvm::StringRef::npos)
41      Diags.Report(diag::warn_fe_macro_contains_embedded_newline)
42        << MacroName;
43    Builder.defineMacro(MacroName, MacroBody.substr(0, End));
44  } else {
45    // Push "macroname 1".
46    Builder.defineMacro(Macro);
47  }
48}
49
50std::string clang::NormalizeDashIncludePath(llvm::StringRef File) {
51  // Implicit include paths should be resolved relative to the current
52  // working directory first, and then use the regular header search
53  // mechanism. The proper way to handle this is to have the
54  // predefines buffer located at the current working directory, but
55  // it has not file entry. For now, workaround this by using an
56  // absolute path if we find the file here, and otherwise letting
57  // header search handle it.
58  llvm::sys::Path Path(File);
59  Path.makeAbsolute();
60  if (!Path.exists())
61    Path = File;
62
63  return Lexer::Stringify(Path.str());
64}
65
66/// AddImplicitInclude - Add an implicit #include of the specified file to the
67/// predefines buffer.
68static void AddImplicitInclude(MacroBuilder &Builder, llvm::StringRef File) {
69  Builder.append("#include \"" +
70                 llvm::Twine(NormalizeDashIncludePath(File)) + "\"");
71}
72
73static void AddImplicitIncludeMacros(MacroBuilder &Builder,
74                                     llvm::StringRef File) {
75  Builder.append("#__include_macros \"" +
76                 llvm::Twine(NormalizeDashIncludePath(File)) + "\"");
77  // Marker token to stop the __include_macros fetch loop.
78  Builder.append("##"); // ##?
79}
80
81/// AddImplicitIncludePTH - Add an implicit #include using the original file
82///  used to generate a PTH cache.
83static void AddImplicitIncludePTH(MacroBuilder &Builder, Preprocessor &PP,
84                                  llvm::StringRef ImplicitIncludePTH) {
85  PTHManager *P = PP.getPTHManager();
86  assert(P && "No PTHManager.");
87  // Null check 'P' in the corner case where it couldn't be created.
88  const char *OriginalFile = P ? P->getOriginalSourceFile() : 0;
89
90  if (!OriginalFile) {
91    PP.getDiagnostics().Report(diag::err_fe_pth_file_has_no_source_header)
92      << ImplicitIncludePTH;
93    return;
94  }
95
96  AddImplicitInclude(Builder, OriginalFile);
97}
98
99/// PickFP - This is used to pick a value based on the FP semantics of the
100/// specified FP model.
101template <typename T>
102static T PickFP(const llvm::fltSemantics *Sem, T IEEESingleVal,
103                T IEEEDoubleVal, T X87DoubleExtendedVal, T PPCDoubleDoubleVal,
104                T IEEEQuadVal) {
105  if (Sem == (const llvm::fltSemantics*)&llvm::APFloat::IEEEsingle)
106    return IEEESingleVal;
107  if (Sem == (const llvm::fltSemantics*)&llvm::APFloat::IEEEdouble)
108    return IEEEDoubleVal;
109  if (Sem == (const llvm::fltSemantics*)&llvm::APFloat::x87DoubleExtended)
110    return X87DoubleExtendedVal;
111  if (Sem == (const llvm::fltSemantics*)&llvm::APFloat::PPCDoubleDouble)
112    return PPCDoubleDoubleVal;
113  assert(Sem == (const llvm::fltSemantics*)&llvm::APFloat::IEEEquad);
114  return IEEEQuadVal;
115}
116
117static void DefineFloatMacros(MacroBuilder &Builder, llvm::StringRef Prefix,
118                              const llvm::fltSemantics *Sem) {
119  const char *DenormMin, *Epsilon, *Max, *Min;
120  DenormMin = PickFP(Sem, "1.40129846e-45F", "4.9406564584124654e-324",
121                     "3.64519953188247460253e-4951L",
122                     "4.94065645841246544176568792868221e-324L",
123                     "6.47517511943802511092443895822764655e-4966L");
124  int Digits = PickFP(Sem, 6, 15, 18, 31, 33);
125  Epsilon = PickFP(Sem, "1.19209290e-7F", "2.2204460492503131e-16",
126                   "1.08420217248550443401e-19L",
127                   "4.94065645841246544176568792868221e-324L",
128                   "1.92592994438723585305597794258492732e-34L");
129  int MantissaDigits = PickFP(Sem, 24, 53, 64, 106, 113);
130  int Min10Exp = PickFP(Sem, -37, -307, -4931, -291, -4931);
131  int Max10Exp = PickFP(Sem, 38, 308, 4932, 308, 4932);
132  int MinExp = PickFP(Sem, -125, -1021, -16381, -968, -16381);
133  int MaxExp = PickFP(Sem, 128, 1024, 16384, 1024, 16384);
134  Min = PickFP(Sem, "1.17549435e-38F", "2.2250738585072014e-308",
135               "3.36210314311209350626e-4932L",
136               "2.00416836000897277799610805135016e-292L",
137               "3.36210314311209350626267781732175260e-4932L");
138  Max = PickFP(Sem, "3.40282347e+38F", "1.7976931348623157e+308",
139               "1.18973149535723176502e+4932L",
140               "1.79769313486231580793728971405301e+308L",
141               "1.18973149535723176508575932662800702e+4932L");
142
143  llvm::SmallString<32> DefPrefix;
144  DefPrefix = "__";
145  DefPrefix += Prefix;
146  DefPrefix += "_";
147
148  Builder.defineMacro(DefPrefix + "DENORM_MIN__", DenormMin);
149  Builder.defineMacro(DefPrefix + "HAS_DENORM__");
150  Builder.defineMacro(DefPrefix + "DIG__", llvm::Twine(Digits));
151  Builder.defineMacro(DefPrefix + "EPSILON__", llvm::Twine(Epsilon));
152  Builder.defineMacro(DefPrefix + "HAS_INFINITY__");
153  Builder.defineMacro(DefPrefix + "HAS_QUIET_NAN__");
154  Builder.defineMacro(DefPrefix + "MANT_DIG__", llvm::Twine(MantissaDigits));
155
156  Builder.defineMacro(DefPrefix + "MAX_10_EXP__", llvm::Twine(Max10Exp));
157  Builder.defineMacro(DefPrefix + "MAX_EXP__", llvm::Twine(MaxExp));
158  Builder.defineMacro(DefPrefix + "MAX__", llvm::Twine(Max));
159
160  Builder.defineMacro(DefPrefix + "MIN_10_EXP__","("+llvm::Twine(Min10Exp)+")");
161  Builder.defineMacro(DefPrefix + "MIN_EXP__", "("+llvm::Twine(MinExp)+")");
162  Builder.defineMacro(DefPrefix + "MIN__", llvm::Twine(Min));
163}
164
165
166/// DefineTypeSize - Emit a macro to the predefines buffer that declares a macro
167/// named MacroName with the max value for a type with width 'TypeWidth' a
168/// signedness of 'isSigned' and with a value suffix of 'ValSuffix' (e.g. LL).
169static void DefineTypeSize(llvm::StringRef MacroName, unsigned TypeWidth,
170                           llvm::StringRef ValSuffix, bool isSigned,
171                           MacroBuilder& Builder) {
172  long long MaxVal;
173  if (isSigned)
174    MaxVal = (1LL << (TypeWidth - 1)) - 1;
175  else
176    MaxVal = ~0LL >> (64-TypeWidth);
177
178  Builder.defineMacro(MacroName, llvm::Twine(MaxVal) + ValSuffix);
179}
180
181/// DefineTypeSize - An overloaded helper that uses TargetInfo to determine
182/// the width, suffix, and signedness of the given type
183static void DefineTypeSize(llvm::StringRef MacroName, TargetInfo::IntType Ty,
184                           const TargetInfo &TI, MacroBuilder &Builder) {
185  DefineTypeSize(MacroName, TI.getTypeWidth(Ty), TI.getTypeConstantSuffix(Ty),
186                 TI.isTypeSigned(Ty), Builder);
187}
188
189static void DefineType(const llvm::Twine &MacroName, TargetInfo::IntType Ty,
190                       MacroBuilder &Builder) {
191  Builder.defineMacro(MacroName, TargetInfo::getTypeName(Ty));
192}
193
194static void DefineTypeWidth(llvm::StringRef MacroName, TargetInfo::IntType Ty,
195                            const TargetInfo &TI, MacroBuilder &Builder) {
196  Builder.defineMacro(MacroName, llvm::Twine(TI.getTypeWidth(Ty)));
197}
198
199static void DefineTypeSizeof(llvm::StringRef MacroName, unsigned BitWidth,
200                             const TargetInfo &TI, MacroBuilder &Builder) {
201  Builder.defineMacro(MacroName,
202                      llvm::Twine(BitWidth / TI.getCharWidth()));
203}
204
205static void DefineExactWidthIntType(TargetInfo::IntType Ty,
206                               const TargetInfo &TI, MacroBuilder &Builder) {
207  int TypeWidth = TI.getTypeWidth(Ty);
208  DefineType("__INT" + llvm::Twine(TypeWidth) + "_TYPE__", Ty, Builder);
209
210  llvm::StringRef ConstSuffix(TargetInfo::getTypeConstantSuffix(Ty));
211  if (!ConstSuffix.empty())
212    Builder.defineMacro("__INT" + llvm::Twine(TypeWidth) + "_C_SUFFIX__",
213                        ConstSuffix);
214}
215
216static void InitializePredefinedMacros(const TargetInfo &TI,
217                                       const LangOptions &LangOpts,
218                                       const FrontendOptions &FEOpts,
219                                       MacroBuilder &Builder) {
220  // Compiler version introspection macros.
221  Builder.defineMacro("__llvm__");  // LLVM Backend
222  Builder.defineMacro("__clang__"); // Clang Frontend
223#define TOSTR2(X) #X
224#define TOSTR(X) TOSTR2(X)
225  Builder.defineMacro("__clang_major__", TOSTR(CLANG_VERSION_MAJOR));
226  Builder.defineMacro("__clang_minor__", TOSTR(CLANG_VERSION_MINOR));
227#ifdef CLANG_VERSION_PATCHLEVEL
228  Builder.defineMacro("__clang_patchlevel__", TOSTR(CLANG_VERSION_PATCHLEVEL));
229#else
230  Builder.defineMacro("__clang_patchlevel__", "0");
231#endif
232  Builder.defineMacro("__clang_version__",
233                      "\"" CLANG_VERSION_STRING " ("
234                      + getClangFullRepositoryVersion() + ")\"");
235#undef TOSTR
236#undef TOSTR2
237  // Currently claim to be compatible with GCC 4.2.1-5621.
238  Builder.defineMacro("__GNUC_MINOR__", "2");
239  Builder.defineMacro("__GNUC_PATCHLEVEL__", "1");
240  Builder.defineMacro("__GNUC__", "4");
241  Builder.defineMacro("__GXX_ABI_VERSION", "1002");
242  Builder.defineMacro("__VERSION__", "\"4.2.1 Compatible Clang Compiler\"");
243
244  // Initialize language-specific preprocessor defines.
245
246  // These should all be defined in the preprocessor according to the
247  // current language configuration.
248  if (!LangOpts.Microsoft)
249    Builder.defineMacro("__STDC__");
250  if (LangOpts.AsmPreprocessor)
251    Builder.defineMacro("__ASSEMBLER__");
252
253  if (!LangOpts.CPlusPlus) {
254    if (LangOpts.C99)
255      Builder.defineMacro("__STDC_VERSION__", "199901L");
256    else if (!LangOpts.GNUMode && LangOpts.Digraphs)
257      Builder.defineMacro("__STDC_VERSION__", "199409L");
258  }
259
260  // Standard conforming mode?
261  if (!LangOpts.GNUMode)
262    Builder.defineMacro("__STRICT_ANSI__");
263
264  if (LangOpts.CPlusPlus0x)
265    Builder.defineMacro("__GXX_EXPERIMENTAL_CXX0X__");
266
267  if (LangOpts.Freestanding)
268    Builder.defineMacro("__STDC_HOSTED__", "0");
269  else
270    Builder.defineMacro("__STDC_HOSTED__");
271
272  if (LangOpts.ObjC1) {
273    Builder.defineMacro("__OBJC__");
274    if (LangOpts.ObjCNonFragileABI) {
275      Builder.defineMacro("__OBJC2__");
276      Builder.defineMacro("OBJC_ZEROCOST_EXCEPTIONS");
277    }
278
279    if (LangOpts.getGCMode() != LangOptions::NonGC)
280      Builder.defineMacro("__OBJC_GC__");
281
282    if (LangOpts.NeXTRuntime)
283      Builder.defineMacro("__NEXT_RUNTIME__");
284  }
285
286  // darwin_constant_cfstrings controls this. This is also dependent
287  // on other things like the runtime I believe.  This is set even for C code.
288  Builder.defineMacro("__CONSTANT_CFSTRINGS__");
289
290  if (LangOpts.ObjC2)
291    Builder.defineMacro("OBJC_NEW_PROPERTIES");
292
293  if (LangOpts.PascalStrings)
294    Builder.defineMacro("__PASCAL_STRINGS__");
295
296  if (LangOpts.Blocks) {
297    Builder.defineMacro("__block", "__attribute__((__blocks__(byref)))");
298    Builder.defineMacro("__BLOCKS__");
299  }
300
301  if (LangOpts.Exceptions)
302    Builder.defineMacro("__EXCEPTIONS");
303  if (LangOpts.RTTI)
304    Builder.defineMacro("__GXX_RTTI");
305  if (LangOpts.SjLjExceptions)
306    Builder.defineMacro("__USING_SJLJ_EXCEPTIONS__");
307
308  if (LangOpts.CPlusPlus) {
309    Builder.defineMacro("__DEPRECATED");
310    Builder.defineMacro("__GNUG__", "4");
311    Builder.defineMacro("__GXX_WEAK__");
312    if (LangOpts.GNUMode)
313      Builder.defineMacro("__cplusplus");
314    else
315      // C++ [cpp.predefined]p1:
316      //   The name_ _cplusplusis defined to the value199711Lwhen compiling a
317      //   C++ translation unit.
318      Builder.defineMacro("__cplusplus", "199711L");
319    Builder.defineMacro("__private_extern__", "extern");
320  }
321
322  if (LangOpts.Microsoft) {
323    // Filter out some microsoft extensions when trying to parse in ms-compat
324    // mode.
325    Builder.defineMacro("__int8", "__INT8_TYPE__");
326    Builder.defineMacro("__int16", "__INT16_TYPE__");
327    Builder.defineMacro("__int32", "__INT32_TYPE__");
328    Builder.defineMacro("__int64", "__INT64_TYPE__");
329    // Both __PRETTY_FUNCTION__ and __FUNCTION__ are GCC extensions, however
330    // VC++ appears to only like __FUNCTION__.
331    Builder.defineMacro("__PRETTY_FUNCTION__", "__FUNCTION__");
332    // Work around some issues with Visual C++ headerws.
333    if (LangOpts.CPlusPlus) {
334      // Since we define wchar_t in C++ mode.
335      Builder.defineMacro("_WCHAR_T_DEFINED");
336      Builder.defineMacro("_NATIVE_WCHAR_T_DEFINED");
337      // FIXME:  This should be temporary until we have a __pragma
338      // solution, to avoid some errors flagged in VC++ headers.
339      Builder.defineMacro("_CRT_SECURE_CPP_OVERLOAD_SECURE_NAMES", "0");
340    }
341  }
342
343  if (LangOpts.Optimize)
344    Builder.defineMacro("__OPTIMIZE__");
345  if (LangOpts.OptimizeSize)
346    Builder.defineMacro("__OPTIMIZE_SIZE__");
347
348  // Initialize target-specific preprocessor defines.
349
350  // Define type sizing macros based on the target properties.
351  assert(TI.getCharWidth() == 8 && "Only support 8-bit char so far");
352  Builder.defineMacro("__CHAR_BIT__", "8");
353
354  DefineTypeSize("__SCHAR_MAX__", TI.getCharWidth(), "", true, Builder);
355  DefineTypeSize("__SHRT_MAX__", TargetInfo::SignedShort, TI, Builder);
356  DefineTypeSize("__INT_MAX__", TargetInfo::SignedInt, TI, Builder);
357  DefineTypeSize("__LONG_MAX__", TargetInfo::SignedLong, TI, Builder);
358  DefineTypeSize("__LONG_LONG_MAX__", TargetInfo::SignedLongLong, TI, Builder);
359  DefineTypeSize("__WCHAR_MAX__", TI.getWCharType(), TI, Builder);
360  DefineTypeSize("__INTMAX_MAX__", TI.getIntMaxType(), TI, Builder);
361
362  DefineTypeSizeof("__SIZEOF_DOUBLE__", TI.getDoubleWidth(), TI, Builder);
363  DefineTypeSizeof("__SIZEOF_FLOAT__", TI.getFloatWidth(), TI, Builder);
364  DefineTypeSizeof("__SIZEOF_INT__", TI.getIntWidth(), TI, Builder);
365  DefineTypeSizeof("__SIZEOF_LONG__", TI.getLongWidth(), TI, Builder);
366  DefineTypeSizeof("__SIZEOF_LONG_DOUBLE__",TI.getLongDoubleWidth(),TI,Builder);
367  DefineTypeSizeof("__SIZEOF_LONG_LONG__", TI.getLongLongWidth(), TI, Builder);
368  DefineTypeSizeof("__SIZEOF_POINTER__", TI.getPointerWidth(0), TI, Builder);
369  DefineTypeSizeof("__SIZEOF_SHORT__", TI.getShortWidth(), TI, Builder);
370  DefineTypeSizeof("__SIZEOF_PTRDIFF_T__",
371                   TI.getTypeWidth(TI.getPtrDiffType(0)), TI, Builder);
372  DefineTypeSizeof("__SIZEOF_SIZE_T__",
373                   TI.getTypeWidth(TI.getSizeType()), TI, Builder);
374  DefineTypeSizeof("__SIZEOF_WCHAR_T__",
375                   TI.getTypeWidth(TI.getWCharType()), TI, Builder);
376  DefineTypeSizeof("__SIZEOF_WINT_T__",
377                   TI.getTypeWidth(TI.getWIntType()), TI, Builder);
378
379  DefineType("__INTMAX_TYPE__", TI.getIntMaxType(), Builder);
380  DefineType("__UINTMAX_TYPE__", TI.getUIntMaxType(), Builder);
381  DefineTypeWidth("__INTMAX_WIDTH__",  TI.getIntMaxType(), TI, Builder);
382  DefineType("__PTRDIFF_TYPE__", TI.getPtrDiffType(0), Builder);
383  DefineTypeWidth("__PTRDIFF_WIDTH__", TI.getPtrDiffType(0), TI, Builder);
384  DefineType("__INTPTR_TYPE__", TI.getIntPtrType(), Builder);
385  DefineTypeWidth("__INTPTR_WIDTH__", TI.getIntPtrType(), TI, Builder);
386  DefineType("__SIZE_TYPE__", TI.getSizeType(), Builder);
387  DefineTypeWidth("__SIZE_WIDTH__", TI.getSizeType(), TI, Builder);
388  DefineType("__WCHAR_TYPE__", TI.getWCharType(), Builder);
389  DefineTypeWidth("__WCHAR_WIDTH__", TI.getWCharType(), TI, Builder);
390  DefineType("__WINT_TYPE__", TI.getWIntType(), Builder);
391  DefineTypeWidth("__WINT_WIDTH__", TI.getWIntType(), TI, Builder);
392  DefineTypeWidth("__SIG_ATOMIC_WIDTH__", TI.getSigAtomicType(), TI, Builder);
393  DefineType("__CHAR16_TYPE__", TI.getChar16Type(), Builder);
394  DefineType("__CHAR32_TYPE__", TI.getChar32Type(), Builder);
395
396  DefineFloatMacros(Builder, "FLT", &TI.getFloatFormat());
397  DefineFloatMacros(Builder, "DBL", &TI.getDoubleFormat());
398  DefineFloatMacros(Builder, "LDBL", &TI.getLongDoubleFormat());
399
400  // Define a __POINTER_WIDTH__ macro for stdint.h.
401  Builder.defineMacro("__POINTER_WIDTH__",
402                      llvm::Twine((int)TI.getPointerWidth(0)));
403
404  if (!LangOpts.CharIsSigned)
405    Builder.defineMacro("__CHAR_UNSIGNED__");
406
407  // Define exact-width integer types for stdint.h
408  Builder.defineMacro("__INT" + llvm::Twine(TI.getCharWidth()) + "_TYPE__",
409                      "char");
410
411  if (TI.getShortWidth() > TI.getCharWidth())
412    DefineExactWidthIntType(TargetInfo::SignedShort, TI, Builder);
413
414  if (TI.getIntWidth() > TI.getShortWidth())
415    DefineExactWidthIntType(TargetInfo::SignedInt, TI, Builder);
416
417  if (TI.getLongWidth() > TI.getIntWidth())
418    DefineExactWidthIntType(TargetInfo::SignedLong, TI, Builder);
419
420  if (TI.getLongLongWidth() > TI.getLongWidth())
421    DefineExactWidthIntType(TargetInfo::SignedLongLong, TI, Builder);
422
423  // Add __builtin_va_list typedef.
424  Builder.append(TI.getVAListDeclaration());
425
426  if (const char *Prefix = TI.getUserLabelPrefix())
427    Builder.defineMacro("__USER_LABEL_PREFIX__", Prefix);
428
429  // Build configuration options.  FIXME: these should be controlled by
430  // command line options or something.
431  Builder.defineMacro("__FINITE_MATH_ONLY__", "0");
432
433  if (LangOpts.GNUInline)
434    Builder.defineMacro("__GNUC_GNU_INLINE__");
435  else
436    Builder.defineMacro("__GNUC_STDC_INLINE__");
437
438  if (LangOpts.NoInline)
439    Builder.defineMacro("__NO_INLINE__");
440
441  if (unsigned PICLevel = LangOpts.PICLevel) {
442    Builder.defineMacro("__PIC__", llvm::Twine(PICLevel));
443    Builder.defineMacro("__pic__", llvm::Twine(PICLevel));
444  }
445
446  // Macros to control C99 numerics and <float.h>
447  Builder.defineMacro("__FLT_EVAL_METHOD__", "0");
448  Builder.defineMacro("__FLT_RADIX__", "2");
449  int Dig = PickFP(&TI.getLongDoubleFormat(), -1/*FIXME*/, 17, 21, 33, 36);
450  Builder.defineMacro("__DECIMAL_DIG__", llvm::Twine(Dig));
451
452  if (LangOpts.getStackProtectorMode() == LangOptions::SSPOn)
453    Builder.defineMacro("__SSP__");
454  else if (LangOpts.getStackProtectorMode() == LangOptions::SSPReq)
455    Builder.defineMacro("__SSP_ALL__", "2");
456
457  if (FEOpts.ProgramAction == frontend::RewriteObjC)
458    Builder.defineMacro("__weak", "__attribute__((objc_gc(weak)))");
459
460  // Define a macro that exists only when using the static analyzer.
461  if (FEOpts.ProgramAction == frontend::RunAnalysis)
462    Builder.defineMacro("__clang_analyzer__");
463
464  // Get other target #defines.
465  TI.getTargetDefines(LangOpts, Builder);
466}
467
468// Initialize the remapping of files to alternative contents, e.g.,
469// those specified through other files.
470static void InitializeFileRemapping(Diagnostic &Diags,
471                                    SourceManager &SourceMgr,
472                                    FileManager &FileMgr,
473                                    const PreprocessorOptions &InitOpts) {
474  // Remap files in the source manager (with buffers).
475  for (PreprocessorOptions::remapped_file_buffer_iterator
476         Remap = InitOpts.remapped_file_buffer_begin(),
477         RemapEnd = InitOpts.remapped_file_buffer_end();
478       Remap != RemapEnd;
479       ++Remap) {
480    // Create the file entry for the file that we're mapping from.
481    const FileEntry *FromFile = FileMgr.getVirtualFile(Remap->first,
482                                                Remap->second->getBufferSize(),
483                                                       0);
484    if (!FromFile) {
485      Diags.Report(diag::err_fe_remap_missing_from_file)
486        << Remap->first;
487      delete Remap->second;
488      continue;
489    }
490
491    // Override the contents of the "from" file with the contents of
492    // the "to" file.
493    SourceMgr.overrideFileContents(FromFile, Remap->second);
494  }
495
496  // Remap files in the source manager (with other files).
497  for (PreprocessorOptions::remapped_file_iterator
498       Remap = InitOpts.remapped_file_begin(),
499       RemapEnd = InitOpts.remapped_file_end();
500       Remap != RemapEnd;
501       ++Remap) {
502    // Find the file that we're mapping to.
503    const FileEntry *ToFile = FileMgr.getFile(Remap->second);
504    if (!ToFile) {
505      Diags.Report(diag::err_fe_remap_missing_to_file)
506      << Remap->first << Remap->second;
507      continue;
508    }
509
510    // Create the file entry for the file that we're mapping from.
511    const FileEntry *FromFile = FileMgr.getVirtualFile(Remap->first,
512                                                       ToFile->getSize(),
513                                                       0);
514    if (!FromFile) {
515      Diags.Report(diag::err_fe_remap_missing_from_file)
516      << Remap->first;
517      continue;
518    }
519
520    // Load the contents of the file we're mapping to.
521    std::string ErrorStr;
522    const llvm::MemoryBuffer *Buffer
523    = llvm::MemoryBuffer::getFile(ToFile->getName(), &ErrorStr);
524    if (!Buffer) {
525      Diags.Report(diag::err_fe_error_opening)
526        << Remap->second << ErrorStr;
527      continue;
528    }
529
530    // Override the contents of the "from" file with the contents of
531    // the "to" file.
532    SourceMgr.overrideFileContents(FromFile, Buffer);
533  }
534}
535
536/// InitializePreprocessor - Initialize the preprocessor getting it and the
537/// environment ready to process a single file. This returns true on error.
538///
539void clang::InitializePreprocessor(Preprocessor &PP,
540                                   const PreprocessorOptions &InitOpts,
541                                   const HeaderSearchOptions &HSOpts,
542                                   const FrontendOptions &FEOpts) {
543  std::string PredefineBuffer;
544  PredefineBuffer.reserve(4080);
545  llvm::raw_string_ostream Predefines(PredefineBuffer);
546  MacroBuilder Builder(Predefines);
547
548  InitializeFileRemapping(PP.getDiagnostics(), PP.getSourceManager(),
549                          PP.getFileManager(), InitOpts);
550
551  // Emit line markers for various builtin sections of the file.  We don't do
552  // this in asm preprocessor mode, because "# 4" is not a line marker directive
553  // in this mode.
554  if (!PP.getLangOptions().AsmPreprocessor)
555    Builder.append("# 1 \"<built-in>\" 3");
556
557  // Install things like __POWERPC__, __GNUC__, etc into the macro table.
558  if (InitOpts.UsePredefines)
559    InitializePredefinedMacros(PP.getTargetInfo(), PP.getLangOptions(),
560                               FEOpts, Builder);
561
562  // Add on the predefines from the driver.  Wrap in a #line directive to report
563  // that they come from the command line.
564  if (!PP.getLangOptions().AsmPreprocessor)
565    Builder.append("# 1 \"<command line>\" 1");
566
567  // Process #define's and #undef's in the order they are given.
568  for (unsigned i = 0, e = InitOpts.Macros.size(); i != e; ++i) {
569    if (InitOpts.Macros[i].second)  // isUndef
570      Builder.undefineMacro(InitOpts.Macros[i].first);
571    else
572      DefineBuiltinMacro(Builder, InitOpts.Macros[i].first,
573                         PP.getDiagnostics());
574  }
575
576  // If -imacros are specified, include them now.  These are processed before
577  // any -include directives.
578  for (unsigned i = 0, e = InitOpts.MacroIncludes.size(); i != e; ++i)
579    AddImplicitIncludeMacros(Builder, InitOpts.MacroIncludes[i]);
580
581  // Process -include directives.
582  for (unsigned i = 0, e = InitOpts.Includes.size(); i != e; ++i) {
583    const std::string &Path = InitOpts.Includes[i];
584    if (Path == InitOpts.ImplicitPTHInclude)
585      AddImplicitIncludePTH(Builder, PP, Path);
586    else
587      AddImplicitInclude(Builder, Path);
588  }
589
590  // Exit the command line and go back to <built-in> (2 is LC_LEAVE).
591  if (!PP.getLangOptions().AsmPreprocessor)
592    Builder.append("# 1 \"<built-in>\" 2");
593
594  // Copy PredefinedBuffer into the Preprocessor.
595  PP.setPredefines(Predefines.str());
596
597  // Initialize the header search object.
598  ApplyHeaderSearchOptions(PP.getHeaderSearchInfo(), HSOpts,
599                           PP.getLangOptions(),
600                           PP.getTargetInfo().getTriple());
601}
602