InitPreprocessor.cpp revision 219077 
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/FileSystem.h"
26#include "llvm/Support/MemoryBuffer.h"
27#include "llvm/Support/Path.h"
28using namespace clang;
29
30// Append a #define line to Buf for Macro.  Macro should be of the form XXX,
31// in which case we emit "#define XXX 1" or "XXX=Y z W" in which case we emit
32// "#define XXX Y z W".  To get a #define with no value, use "XXX=".
33static void DefineBuiltinMacro(MacroBuilder &Builder, llvm::StringRef Macro,
34                               Diagnostic &Diags) {
35  std::pair<llvm::StringRef, llvm::StringRef> MacroPair = Macro.split('=');
36  llvm::StringRef MacroName = MacroPair.first;
37  llvm::StringRef MacroBody = MacroPair.second;
38  if (MacroName.size() != Macro.size()) {
39    // Per GCC -D semantics, the macro ends at \n if it exists.
40    llvm::StringRef::size_type End = MacroBody.find_first_of("\n\r");
41    if (End != llvm::StringRef::npos)
42      Diags.Report(diag::warn_fe_macro_contains_embedded_newline)
43        << MacroName;
44    Builder.defineMacro(MacroName, MacroBody.substr(0, End));
45  } else {
46    // Push "macroname 1".
47    Builder.defineMacro(Macro);
48  }
49}
50
51std::string clang::NormalizeDashIncludePath(llvm::StringRef File,
52                                            FileManager &FileMgr) {
53  // Implicit include paths should be resolved relative to the current
54  // working directory first, and then use the regular header search
55  // mechanism. The proper way to handle this is to have the
56  // predefines buffer located at the current working directory, but
57  // it has no file entry. For now, workaround this by using an
58  // absolute path if we find the file here, and otherwise letting
59  // header search handle it.
60  llvm::SmallString<128> Path(File);
61  llvm::sys::fs::make_absolute(Path);
62  bool exists;
63  if (llvm::sys::fs::exists(Path.str(), exists) || !exists)
64    Path = File;
65  else if (exists)
66    FileMgr.getFile(File);
67
68  return Lexer::Stringify(Path.str());
69}
70
71/// AddImplicitInclude - Add an implicit #include of the specified file to the
72/// predefines buffer.
73static void AddImplicitInclude(MacroBuilder &Builder, llvm::StringRef File,
74                               FileManager &FileMgr) {
75  Builder.append("#include \"" +
76                 llvm::Twine(NormalizeDashIncludePath(File, FileMgr)) + "\"");
77}
78
79static void AddImplicitIncludeMacros(MacroBuilder &Builder,
80                                     llvm::StringRef File,
81                                     FileManager &FileMgr) {
82  Builder.append("#__include_macros \"" +
83                 llvm::Twine(NormalizeDashIncludePath(File, FileMgr)) + "\"");
84  // Marker token to stop the __include_macros fetch loop.
85  Builder.append("##"); // ##?
86}
87
88/// AddImplicitIncludePTH - Add an implicit #include using the original file
89///  used to generate a PTH cache.
90static void AddImplicitIncludePTH(MacroBuilder &Builder, Preprocessor &PP,
91                                  llvm::StringRef ImplicitIncludePTH) {
92  PTHManager *P = PP.getPTHManager();
93  // Null check 'P' in the corner case where it couldn't be created.
94  const char *OriginalFile = P ? P->getOriginalSourceFile() : 0;
95
96  if (!OriginalFile) {
97    PP.getDiagnostics().Report(diag::err_fe_pth_file_has_no_source_header)
98      << ImplicitIncludePTH;
99    return;
100  }
101
102  AddImplicitInclude(Builder, OriginalFile, PP.getFileManager());
103}
104
105/// PickFP - This is used to pick a value based on the FP semantics of the
106/// specified FP model.
107template <typename T>
108static T PickFP(const llvm::fltSemantics *Sem, T IEEESingleVal,
109                T IEEEDoubleVal, T X87DoubleExtendedVal, T PPCDoubleDoubleVal,
110                T IEEEQuadVal) {
111  if (Sem == (const llvm::fltSemantics*)&llvm::APFloat::IEEEsingle)
112    return IEEESingleVal;
113  if (Sem == (const llvm::fltSemantics*)&llvm::APFloat::IEEEdouble)
114    return IEEEDoubleVal;
115  if (Sem == (const llvm::fltSemantics*)&llvm::APFloat::x87DoubleExtended)
116    return X87DoubleExtendedVal;
117  if (Sem == (const llvm::fltSemantics*)&llvm::APFloat::PPCDoubleDouble)
118    return PPCDoubleDoubleVal;
119  assert(Sem == (const llvm::fltSemantics*)&llvm::APFloat::IEEEquad);
120  return IEEEQuadVal;
121}
122
123static void DefineFloatMacros(MacroBuilder &Builder, llvm::StringRef Prefix,
124                              const llvm::fltSemantics *Sem) {
125  const char *DenormMin, *Epsilon, *Max, *Min;
126  DenormMin = PickFP(Sem, "1.40129846e-45F", "4.9406564584124654e-324",
127                     "3.64519953188247460253e-4951L",
128                     "4.94065645841246544176568792868221e-324L",
129                     "6.47517511943802511092443895822764655e-4966L");
130  int Digits = PickFP(Sem, 6, 15, 18, 31, 33);
131  Epsilon = PickFP(Sem, "1.19209290e-7F", "2.2204460492503131e-16",
132                   "1.08420217248550443401e-19L",
133                   "4.94065645841246544176568792868221e-324L",
134                   "1.92592994438723585305597794258492732e-34L");
135  int MantissaDigits = PickFP(Sem, 24, 53, 64, 106, 113);
136  int Min10Exp = PickFP(Sem, -37, -307, -4931, -291, -4931);
137  int Max10Exp = PickFP(Sem, 38, 308, 4932, 308, 4932);
138  int MinExp = PickFP(Sem, -125, -1021, -16381, -968, -16381);
139  int MaxExp = PickFP(Sem, 128, 1024, 16384, 1024, 16384);
140  Min = PickFP(Sem, "1.17549435e-38F", "2.2250738585072014e-308",
141               "3.36210314311209350626e-4932L",
142               "2.00416836000897277799610805135016e-292L",
143               "3.36210314311209350626267781732175260e-4932L");
144  Max = PickFP(Sem, "3.40282347e+38F", "1.7976931348623157e+308",
145               "1.18973149535723176502e+4932L",
146               "1.79769313486231580793728971405301e+308L",
147               "1.18973149535723176508575932662800702e+4932L");
148
149  llvm::SmallString<32> DefPrefix;
150  DefPrefix = "__";
151  DefPrefix += Prefix;
152  DefPrefix += "_";
153
154  Builder.defineMacro(DefPrefix + "DENORM_MIN__", DenormMin);
155  Builder.defineMacro(DefPrefix + "HAS_DENORM__");
156  Builder.defineMacro(DefPrefix + "DIG__", llvm::Twine(Digits));
157  Builder.defineMacro(DefPrefix + "EPSILON__", llvm::Twine(Epsilon));
158  Builder.defineMacro(DefPrefix + "HAS_INFINITY__");
159  Builder.defineMacro(DefPrefix + "HAS_QUIET_NAN__");
160  Builder.defineMacro(DefPrefix + "MANT_DIG__", llvm::Twine(MantissaDigits));
161
162  Builder.defineMacro(DefPrefix + "MAX_10_EXP__", llvm::Twine(Max10Exp));
163  Builder.defineMacro(DefPrefix + "MAX_EXP__", llvm::Twine(MaxExp));
164  Builder.defineMacro(DefPrefix + "MAX__", llvm::Twine(Max));
165
166  Builder.defineMacro(DefPrefix + "MIN_10_EXP__","("+llvm::Twine(Min10Exp)+")");
167  Builder.defineMacro(DefPrefix + "MIN_EXP__", "("+llvm::Twine(MinExp)+")");
168  Builder.defineMacro(DefPrefix + "MIN__", llvm::Twine(Min));
169}
170
171
172/// DefineTypeSize - Emit a macro to the predefines buffer that declares a macro
173/// named MacroName with the max value for a type with width 'TypeWidth' a
174/// signedness of 'isSigned' and with a value suffix of 'ValSuffix' (e.g. LL).
175static void DefineTypeSize(llvm::StringRef MacroName, unsigned TypeWidth,
176                           llvm::StringRef ValSuffix, bool isSigned,
177                           MacroBuilder &Builder) {
178  llvm::APInt MaxVal = isSigned ? llvm::APInt::getSignedMaxValue(TypeWidth)
179                                : llvm::APInt::getMaxValue(TypeWidth);
180  Builder.defineMacro(MacroName, MaxVal.toString(10, isSigned) + ValSuffix);
181}
182
183/// DefineTypeSize - An overloaded helper that uses TargetInfo to determine
184/// the width, suffix, and signedness of the given type
185static void DefineTypeSize(llvm::StringRef MacroName, TargetInfo::IntType Ty,
186                           const TargetInfo &TI, MacroBuilder &Builder) {
187  DefineTypeSize(MacroName, TI.getTypeWidth(Ty), TI.getTypeConstantSuffix(Ty),
188                 TI.isTypeSigned(Ty), Builder);
189}
190
191static void DefineType(const llvm::Twine &MacroName, TargetInfo::IntType Ty,
192                       MacroBuilder &Builder) {
193  Builder.defineMacro(MacroName, TargetInfo::getTypeName(Ty));
194}
195
196static void DefineTypeWidth(llvm::StringRef MacroName, TargetInfo::IntType Ty,
197                            const TargetInfo &TI, MacroBuilder &Builder) {
198  Builder.defineMacro(MacroName, llvm::Twine(TI.getTypeWidth(Ty)));
199}
200
201static void DefineTypeSizeof(llvm::StringRef MacroName, unsigned BitWidth,
202                             const TargetInfo &TI, MacroBuilder &Builder) {
203  Builder.defineMacro(MacroName,
204                      llvm::Twine(BitWidth / TI.getCharWidth()));
205}
206
207static void DefineExactWidthIntType(TargetInfo::IntType Ty,
208                               const TargetInfo &TI, MacroBuilder &Builder) {
209  int TypeWidth = TI.getTypeWidth(Ty);
210
211  // Use the target specified int64 type, when appropriate, so that [u]int64_t
212  // ends up being defined in terms of the correct type.
213  if (TypeWidth == 64)
214    Ty = TI.getInt64Type();
215
216  DefineType("__INT" + llvm::Twine(TypeWidth) + "_TYPE__", Ty, Builder);
217
218  llvm::StringRef ConstSuffix(TargetInfo::getTypeConstantSuffix(Ty));
219  if (!ConstSuffix.empty())
220    Builder.defineMacro("__INT" + llvm::Twine(TypeWidth) + "_C_SUFFIX__",
221                        ConstSuffix);
222}
223
224static void InitializePredefinedMacros(const TargetInfo &TI,
225                                       const LangOptions &LangOpts,
226                                       const FrontendOptions &FEOpts,
227                                       MacroBuilder &Builder) {
228  // Compiler version introspection macros.
229  Builder.defineMacro("__llvm__");  // LLVM Backend
230  Builder.defineMacro("__clang__"); // Clang Frontend
231#define TOSTR2(X) #X
232#define TOSTR(X) TOSTR2(X)
233  Builder.defineMacro("__clang_major__", TOSTR(CLANG_VERSION_MAJOR));
234  Builder.defineMacro("__clang_minor__", TOSTR(CLANG_VERSION_MINOR));
235#ifdef CLANG_VERSION_PATCHLEVEL
236  Builder.defineMacro("__clang_patchlevel__", TOSTR(CLANG_VERSION_PATCHLEVEL));
237#else
238  Builder.defineMacro("__clang_patchlevel__", "0");
239#endif
240  Builder.defineMacro("__clang_version__",
241                      "\"" CLANG_VERSION_STRING " ("
242                      + getClangFullRepositoryVersion() + ")\"");
243#undef TOSTR
244#undef TOSTR2
245  // Currently claim to be compatible with GCC 4.2.1-5621.
246  Builder.defineMacro("__GNUC_MINOR__", "2");
247  Builder.defineMacro("__GNUC_PATCHLEVEL__", "1");
248  Builder.defineMacro("__GNUC__", "4");
249  Builder.defineMacro("__GXX_ABI_VERSION", "1002");
250  Builder.defineMacro("__VERSION__", "\"4.2.1 Compatible Clang Compiler\"");
251
252  // Initialize language-specific preprocessor defines.
253
254  // These should all be defined in the preprocessor according to the
255  // current language configuration.
256  if (!LangOpts.Microsoft)
257    Builder.defineMacro("__STDC__");
258  if (LangOpts.AsmPreprocessor)
259    Builder.defineMacro("__ASSEMBLER__");
260
261  if (!LangOpts.CPlusPlus) {
262    if (LangOpts.C99)
263      Builder.defineMacro("__STDC_VERSION__", "199901L");
264    else if (!LangOpts.GNUMode && LangOpts.Digraphs)
265      Builder.defineMacro("__STDC_VERSION__", "199409L");
266  }
267
268  // Standard conforming mode?
269  if (!LangOpts.GNUMode)
270    Builder.defineMacro("__STRICT_ANSI__");
271
272  if (LangOpts.CPlusPlus0x)
273    Builder.defineMacro("__GXX_EXPERIMENTAL_CXX0X__");
274
275  if (LangOpts.Freestanding)
276    Builder.defineMacro("__STDC_HOSTED__", "0");
277  else
278    Builder.defineMacro("__STDC_HOSTED__");
279
280  if (LangOpts.ObjC1) {
281    Builder.defineMacro("__OBJC__");
282    if (LangOpts.ObjCNonFragileABI) {
283      Builder.defineMacro("__OBJC2__");
284      Builder.defineMacro("OBJC_ZEROCOST_EXCEPTIONS");
285    }
286
287    if (LangOpts.getGCMode() != LangOptions::NonGC)
288      Builder.defineMacro("__OBJC_GC__");
289
290    if (LangOpts.NeXTRuntime)
291      Builder.defineMacro("__NEXT_RUNTIME__");
292  }
293
294  // darwin_constant_cfstrings controls this. This is also dependent
295  // on other things like the runtime I believe.  This is set even for C code.
296  Builder.defineMacro("__CONSTANT_CFSTRINGS__");
297
298  if (LangOpts.ObjC2)
299    Builder.defineMacro("OBJC_NEW_PROPERTIES");
300
301  if (LangOpts.PascalStrings)
302    Builder.defineMacro("__PASCAL_STRINGS__");
303
304  if (LangOpts.Blocks) {
305    Builder.defineMacro("__block", "__attribute__((__blocks__(byref)))");
306    Builder.defineMacro("__BLOCKS__");
307  }
308
309  if (LangOpts.Exceptions)
310    Builder.defineMacro("__EXCEPTIONS");
311  if (LangOpts.RTTI)
312    Builder.defineMacro("__GXX_RTTI");
313  if (LangOpts.SjLjExceptions)
314    Builder.defineMacro("__USING_SJLJ_EXCEPTIONS__");
315
316  if (LangOpts.CPlusPlus) {
317    Builder.defineMacro("__DEPRECATED");
318    Builder.defineMacro("__GNUG__", "4");
319    Builder.defineMacro("__GXX_WEAK__");
320    if (LangOpts.GNUMode)
321      Builder.defineMacro("__cplusplus");
322    else
323      // C++ [cpp.predefined]p1:
324      //   The name_ _cplusplusis defined to the value 199711L when compiling a
325      //   C++ translation unit.
326      Builder.defineMacro("__cplusplus", "199711L");
327    Builder.defineMacro("__private_extern__", "extern");
328  }
329
330  if (LangOpts.Microsoft) {
331    // Filter out some microsoft extensions when trying to parse in ms-compat
332    // mode.
333    Builder.defineMacro("__int8", "__INT8_TYPE__");
334    Builder.defineMacro("__int16", "__INT16_TYPE__");
335    Builder.defineMacro("__int32", "__INT32_TYPE__");
336    Builder.defineMacro("__int64", "__INT64_TYPE__");
337    // Both __PRETTY_FUNCTION__ and __FUNCTION__ are GCC extensions, however
338    // VC++ appears to only like __FUNCTION__.
339    Builder.defineMacro("__PRETTY_FUNCTION__", "__FUNCTION__");
340    // Work around some issues with Visual C++ headerws.
341    if (LangOpts.CPlusPlus) {
342      // Since we define wchar_t in C++ mode.
343      Builder.defineMacro("_WCHAR_T_DEFINED");
344      Builder.defineMacro("_NATIVE_WCHAR_T_DEFINED");
345      Builder.append("class type_info;");
346    }
347
348    if (LangOpts.CPlusPlus0x) {
349      Builder.defineMacro("_HAS_CHAR16_T_LANGUAGE_SUPPORT", "1");
350    }
351  }
352
353  if (LangOpts.Optimize)
354    Builder.defineMacro("__OPTIMIZE__");
355  if (LangOpts.OptimizeSize)
356    Builder.defineMacro("__OPTIMIZE_SIZE__");
357
358  // Initialize target-specific preprocessor defines.
359
360  // Define type sizing macros based on the target properties.
361  assert(TI.getCharWidth() == 8 && "Only support 8-bit char so far");
362  Builder.defineMacro("__CHAR_BIT__", "8");
363
364  DefineTypeSize("__SCHAR_MAX__", TI.getCharWidth(), "", true, Builder);
365  DefineTypeSize("__SHRT_MAX__", TargetInfo::SignedShort, TI, Builder);
366  DefineTypeSize("__INT_MAX__", TargetInfo::SignedInt, TI, Builder);
367  DefineTypeSize("__LONG_MAX__", TargetInfo::SignedLong, TI, Builder);
368  DefineTypeSize("__LONG_LONG_MAX__", TargetInfo::SignedLongLong, TI, Builder);
369  DefineTypeSize("__WCHAR_MAX__", TI.getWCharType(), TI, Builder);
370  DefineTypeSize("__INTMAX_MAX__", TI.getIntMaxType(), TI, Builder);
371
372  DefineTypeSizeof("__SIZEOF_DOUBLE__", TI.getDoubleWidth(), TI, Builder);
373  DefineTypeSizeof("__SIZEOF_FLOAT__", TI.getFloatWidth(), TI, Builder);
374  DefineTypeSizeof("__SIZEOF_INT__", TI.getIntWidth(), TI, Builder);
375  DefineTypeSizeof("__SIZEOF_LONG__", TI.getLongWidth(), TI, Builder);
376  DefineTypeSizeof("__SIZEOF_LONG_DOUBLE__",TI.getLongDoubleWidth(),TI,Builder);
377  DefineTypeSizeof("__SIZEOF_LONG_LONG__", TI.getLongLongWidth(), TI, Builder);
378  DefineTypeSizeof("__SIZEOF_POINTER__", TI.getPointerWidth(0), TI, Builder);
379  DefineTypeSizeof("__SIZEOF_SHORT__", TI.getShortWidth(), TI, Builder);
380  DefineTypeSizeof("__SIZEOF_PTRDIFF_T__",
381                   TI.getTypeWidth(TI.getPtrDiffType(0)), TI, Builder);
382  DefineTypeSizeof("__SIZEOF_SIZE_T__",
383                   TI.getTypeWidth(TI.getSizeType()), TI, Builder);
384  DefineTypeSizeof("__SIZEOF_WCHAR_T__",
385                   TI.getTypeWidth(TI.getWCharType()), TI, Builder);
386  DefineTypeSizeof("__SIZEOF_WINT_T__",
387                   TI.getTypeWidth(TI.getWIntType()), TI, Builder);
388
389  DefineType("__INTMAX_TYPE__", TI.getIntMaxType(), Builder);
390  DefineType("__UINTMAX_TYPE__", TI.getUIntMaxType(), Builder);
391  DefineTypeWidth("__INTMAX_WIDTH__",  TI.getIntMaxType(), TI, Builder);
392  DefineType("__PTRDIFF_TYPE__", TI.getPtrDiffType(0), Builder);
393  DefineTypeWidth("__PTRDIFF_WIDTH__", TI.getPtrDiffType(0), TI, Builder);
394  DefineType("__INTPTR_TYPE__", TI.getIntPtrType(), Builder);
395  DefineTypeWidth("__INTPTR_WIDTH__", TI.getIntPtrType(), TI, Builder);
396  DefineType("__SIZE_TYPE__", TI.getSizeType(), Builder);
397  DefineTypeWidth("__SIZE_WIDTH__", TI.getSizeType(), TI, Builder);
398  DefineType("__WCHAR_TYPE__", TI.getWCharType(), Builder);
399  DefineTypeWidth("__WCHAR_WIDTH__", TI.getWCharType(), TI, Builder);
400  DefineType("__WINT_TYPE__", TI.getWIntType(), Builder);
401  DefineTypeWidth("__WINT_WIDTH__", TI.getWIntType(), TI, Builder);
402  DefineTypeWidth("__SIG_ATOMIC_WIDTH__", TI.getSigAtomicType(), TI, Builder);
403  DefineType("__CHAR16_TYPE__", TI.getChar16Type(), Builder);
404  DefineType("__CHAR32_TYPE__", TI.getChar32Type(), Builder);
405
406  DefineFloatMacros(Builder, "FLT", &TI.getFloatFormat());
407  DefineFloatMacros(Builder, "DBL", &TI.getDoubleFormat());
408  DefineFloatMacros(Builder, "LDBL", &TI.getLongDoubleFormat());
409
410  // Define a __POINTER_WIDTH__ macro for stdint.h.
411  Builder.defineMacro("__POINTER_WIDTH__",
412                      llvm::Twine((int)TI.getPointerWidth(0)));
413
414  if (!LangOpts.CharIsSigned)
415    Builder.defineMacro("__CHAR_UNSIGNED__");
416
417  // Define exact-width integer types for stdint.h
418  Builder.defineMacro("__INT" + llvm::Twine(TI.getCharWidth()) + "_TYPE__",
419                      "char");
420
421  if (TI.getShortWidth() > TI.getCharWidth())
422    DefineExactWidthIntType(TargetInfo::SignedShort, TI, Builder);
423
424  if (TI.getIntWidth() > TI.getShortWidth())
425    DefineExactWidthIntType(TargetInfo::SignedInt, TI, Builder);
426
427  if (TI.getLongWidth() > TI.getIntWidth())
428    DefineExactWidthIntType(TargetInfo::SignedLong, TI, Builder);
429
430  if (TI.getLongLongWidth() > TI.getLongWidth())
431    DefineExactWidthIntType(TargetInfo::SignedLongLong, TI, Builder);
432
433  // Add __builtin_va_list typedef.
434  Builder.append(TI.getVAListDeclaration());
435
436  if (const char *Prefix = TI.getUserLabelPrefix())
437    Builder.defineMacro("__USER_LABEL_PREFIX__", Prefix);
438
439  // Build configuration options.  FIXME: these should be controlled by
440  // command line options or something.
441  Builder.defineMacro("__FINITE_MATH_ONLY__", "0");
442
443  if (LangOpts.GNUInline)
444    Builder.defineMacro("__GNUC_GNU_INLINE__");
445  else
446    Builder.defineMacro("__GNUC_STDC_INLINE__");
447
448  if (LangOpts.NoInline)
449    Builder.defineMacro("__NO_INLINE__");
450
451  if (unsigned PICLevel = LangOpts.PICLevel) {
452    Builder.defineMacro("__PIC__", llvm::Twine(PICLevel));
453    Builder.defineMacro("__pic__", llvm::Twine(PICLevel));
454  }
455
456  // Macros to control C99 numerics and <float.h>
457  Builder.defineMacro("__FLT_EVAL_METHOD__", "0");
458  Builder.defineMacro("__FLT_RADIX__", "2");
459  int Dig = PickFP(&TI.getLongDoubleFormat(), -1/*FIXME*/, 17, 21, 33, 36);
460  Builder.defineMacro("__DECIMAL_DIG__", llvm::Twine(Dig));
461
462  if (LangOpts.getStackProtectorMode() == LangOptions::SSPOn)
463    Builder.defineMacro("__SSP__");
464  else if (LangOpts.getStackProtectorMode() == LangOptions::SSPReq)
465    Builder.defineMacro("__SSP_ALL__", "2");
466
467  if (FEOpts.ProgramAction == frontend::RewriteObjC)
468    Builder.defineMacro("__weak", "__attribute__((objc_gc(weak)))");
469
470  // Define a macro that exists only when using the static analyzer.
471  if (FEOpts.ProgramAction == frontend::RunAnalysis)
472    Builder.defineMacro("__clang_analyzer__");
473
474  if (LangOpts.FastRelaxedMath)
475    Builder.defineMacro("__FAST_RELAXED_MATH__");
476
477  // Get other target #defines.
478  TI.getTargetDefines(LangOpts, Builder);
479}
480
481// Initialize the remapping of files to alternative contents, e.g.,
482// those specified through other files.
483static void InitializeFileRemapping(Diagnostic &Diags,
484                                    SourceManager &SourceMgr,
485                                    FileManager &FileMgr,
486                                    const PreprocessorOptions &InitOpts) {
487  // Remap files in the source manager (with buffers).
488  for (PreprocessorOptions::const_remapped_file_buffer_iterator
489         Remap = InitOpts.remapped_file_buffer_begin(),
490         RemapEnd = InitOpts.remapped_file_buffer_end();
491       Remap != RemapEnd;
492       ++Remap) {
493    // Create the file entry for the file that we're mapping from.
494    const FileEntry *FromFile = FileMgr.getVirtualFile(Remap->first,
495                                                Remap->second->getBufferSize(),
496                                                       0);
497    if (!FromFile) {
498      Diags.Report(diag::err_fe_remap_missing_from_file)
499        << Remap->first;
500      if (!InitOpts.RetainRemappedFileBuffers)
501        delete Remap->second;
502      continue;
503    }
504
505    // Override the contents of the "from" file with the contents of
506    // the "to" file.
507    SourceMgr.overrideFileContents(FromFile, Remap->second,
508                                   InitOpts.RetainRemappedFileBuffers);
509  }
510
511  // Remap files in the source manager (with other files).
512  for (PreprocessorOptions::const_remapped_file_iterator
513         Remap = InitOpts.remapped_file_begin(),
514         RemapEnd = InitOpts.remapped_file_end();
515       Remap != RemapEnd;
516       ++Remap) {
517    // Find the file that we're mapping to.
518    const FileEntry *ToFile = FileMgr.getFile(Remap->second);
519    if (!ToFile) {
520      Diags.Report(diag::err_fe_remap_missing_to_file)
521      << Remap->first << Remap->second;
522      continue;
523    }
524
525    // Create the file entry for the file that we're mapping from.
526    const FileEntry *FromFile = FileMgr.getVirtualFile(Remap->first,
527                                                       ToFile->getSize(), 0);
528    if (!FromFile) {
529      Diags.Report(diag::err_fe_remap_missing_from_file)
530      << Remap->first;
531      continue;
532    }
533
534    // Load the contents of the file we're mapping to.
535    std::string ErrorStr;
536    const llvm::MemoryBuffer *Buffer
537      = FileMgr.getBufferForFile(ToFile->getName(), &ErrorStr);
538    if (!Buffer) {
539      Diags.Report(diag::err_fe_error_opening)
540        << Remap->second << ErrorStr;
541      continue;
542    }
543
544    // Override the contents of the "from" file with the contents of
545    // the "to" file.
546    SourceMgr.overrideFileContents(FromFile, Buffer);
547  }
548}
549
550/// InitializePreprocessor - Initialize the preprocessor getting it and the
551/// environment ready to process a single file. This returns true on error.
552///
553void clang::InitializePreprocessor(Preprocessor &PP,
554                                   const PreprocessorOptions &InitOpts,
555                                   const HeaderSearchOptions &HSOpts,
556                                   const FrontendOptions &FEOpts) {
557  std::string PredefineBuffer;
558  PredefineBuffer.reserve(4080);
559  llvm::raw_string_ostream Predefines(PredefineBuffer);
560  MacroBuilder Builder(Predefines);
561
562  InitializeFileRemapping(PP.getDiagnostics(), PP.getSourceManager(),
563                          PP.getFileManager(), InitOpts);
564
565  // Emit line markers for various builtin sections of the file.  We don't do
566  // this in asm preprocessor mode, because "# 4" is not a line marker directive
567  // in this mode.
568  if (!PP.getLangOptions().AsmPreprocessor)
569    Builder.append("# 1 \"<built-in>\" 3");
570
571  // Install things like __POWERPC__, __GNUC__, etc into the macro table.
572  if (InitOpts.UsePredefines)
573    InitializePredefinedMacros(PP.getTargetInfo(), PP.getLangOptions(),
574                               FEOpts, Builder);
575
576  // Add on the predefines from the driver.  Wrap in a #line directive to report
577  // that they come from the command line.
578  if (!PP.getLangOptions().AsmPreprocessor)
579    Builder.append("# 1 \"<command line>\" 1");
580
581  // Process #define's and #undef's in the order they are given.
582  for (unsigned i = 0, e = InitOpts.Macros.size(); i != e; ++i) {
583    if (InitOpts.Macros[i].second)  // isUndef
584      Builder.undefineMacro(InitOpts.Macros[i].first);
585    else
586      DefineBuiltinMacro(Builder, InitOpts.Macros[i].first,
587                         PP.getDiagnostics());
588  }
589
590  // If -imacros are specified, include them now.  These are processed before
591  // any -include directives.
592  for (unsigned i = 0, e = InitOpts.MacroIncludes.size(); i != e; ++i)
593    AddImplicitIncludeMacros(Builder, InitOpts.MacroIncludes[i],
594                             PP.getFileManager());
595
596  // Process -include directives.
597  for (unsigned i = 0, e = InitOpts.Includes.size(); i != e; ++i) {
598    const std::string &Path = InitOpts.Includes[i];
599    if (Path == InitOpts.ImplicitPTHInclude)
600      AddImplicitIncludePTH(Builder, PP, Path);
601    else
602      AddImplicitInclude(Builder, Path, PP.getFileManager());
603  }
604
605  // Exit the command line and go back to <built-in> (2 is LC_LEAVE).
606  if (!PP.getLangOptions().AsmPreprocessor)
607    Builder.append("# 1 \"<built-in>\" 2");
608
609  // Instruct the preprocessor to skip the preamble.
610  PP.setSkipMainFilePreamble(InitOpts.PrecompiledPreambleBytes.first,
611                             InitOpts.PrecompiledPreambleBytes.second);
612
613  // Copy PredefinedBuffer into the Preprocessor.
614  PP.setPredefines(Predefines.str());
615
616  // Initialize the header search object.
617  ApplyHeaderSearchOptions(PP.getHeaderSearchInfo(), HSOpts,
618                           PP.getLangOptions(),
619                           PP.getTargetInfo().getTriple());
620}
621