InitPreprocessor.cpp revision 186696bee3b3544d942bb43041595e210de577c6 
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/Frontend/Utils.h"
15#include "clang/Basic/TargetInfo.h"
16#include "clang/Frontend/PreprocessorOptions.h"
17#include "clang/Lex/Preprocessor.h"
18#include "llvm/ADT/StringExtras.h"
19#include "llvm/ADT/STLExtras.h"
20#include "llvm/System/Path.h"
21using namespace clang;
22
23// Append a #define line to Buf for Macro.  Macro should be of the form XXX,
24// in which case we emit "#define XXX 1" or "XXX=Y z W" in which case we emit
25// "#define XXX Y z W".  To get a #define with no value, use "XXX=".
26static void DefineBuiltinMacro(std::vector<char> &Buf, const char *Macro) {
27  const char *Command = "#define ";
28  Buf.insert(Buf.end(), Command, Command+strlen(Command));
29  if (const char *Equal = strchr(Macro, '=')) {
30    // Turn the = into ' '.
31    Buf.insert(Buf.end(), Macro, Equal);
32    Buf.push_back(' ');
33
34    // Per GCC -D semantics, the macro ends at \n if it exists.
35    const char *End = strpbrk(Equal, "\n\r");
36    if (End) {
37      fprintf(stderr, "warning: macro '%s' contains embedded newline, text "
38              "after the newline is ignored.\n",
39              std::string(Macro, Equal).c_str());
40    } else {
41      End = Equal+strlen(Equal);
42    }
43
44    Buf.insert(Buf.end(), Equal+1, End);
45  } else {
46    // Push "macroname 1".
47    Buf.insert(Buf.end(), Macro, Macro+strlen(Macro));
48    Buf.push_back(' ');
49    Buf.push_back('1');
50  }
51  Buf.push_back('\n');
52}
53
54// Append a #undef line to Buf for Macro.  Macro should be of the form XXX
55// and we emit "#undef XXX".
56static void UndefineBuiltinMacro(std::vector<char> &Buf, const char *Macro) {
57  // Push "macroname".
58  const char *Command = "#undef ";
59  Buf.insert(Buf.end(), Command, Command+strlen(Command));
60  Buf.insert(Buf.end(), Macro, Macro+strlen(Macro));
61  Buf.push_back('\n');
62}
63
64std::string clang::NormalizeDashIncludePath(llvm::StringRef File) {
65  // Implicit include paths should be resolved relative to the current
66  // working directory first, and then use the regular header search
67  // mechanism. The proper way to handle this is to have the
68  // predefines buffer located at the current working directory, but
69  // it has not file entry. For now, workaround this by using an
70  // absolute path if we find the file here, and otherwise letting
71  // header search handle it.
72  llvm::sys::Path Path(File);
73  Path.makeAbsolute();
74  if (!Path.exists())
75    Path = File;
76
77  return Lexer::Stringify(Path.str());
78}
79
80/// Add the quoted name of an implicit include file.
81static void AddQuotedIncludePath(std::vector<char> &Buf,
82                                 const std::string &File) {
83
84  // Escape double quotes etc.
85  Buf.push_back('"');
86  std::string EscapedFile = NormalizeDashIncludePath(File);
87  Buf.insert(Buf.end(), EscapedFile.begin(), EscapedFile.end());
88  Buf.push_back('"');
89}
90
91/// AddImplicitInclude - Add an implicit #include of the specified file to the
92/// predefines buffer.
93static void AddImplicitInclude(std::vector<char> &Buf,
94                               const std::string &File) {
95  const char *Inc = "#include ";
96  Buf.insert(Buf.end(), Inc, Inc+strlen(Inc));
97  AddQuotedIncludePath(Buf, File);
98  Buf.push_back('\n');
99}
100
101static void AddImplicitIncludeMacros(std::vector<char> &Buf,
102                                     const std::string &File) {
103  const char *Inc = "#__include_macros ";
104  Buf.insert(Buf.end(), Inc, Inc+strlen(Inc));
105  AddQuotedIncludePath(Buf, File);
106  Buf.push_back('\n');
107  // Marker token to stop the __include_macros fetch loop.
108  const char *Marker = "##\n"; // ##?
109  Buf.insert(Buf.end(), Marker, Marker+strlen(Marker));
110}
111
112/// AddImplicitIncludePTH - Add an implicit #include using the original file
113///  used to generate a PTH cache.
114static void AddImplicitIncludePTH(std::vector<char> &Buf, Preprocessor &PP,
115  const std::string& ImplicitIncludePTH) {
116  PTHManager *P = PP.getPTHManager();
117  assert(P && "No PTHManager.");
118  const char *OriginalFile = P->getOriginalSourceFile();
119
120  if (!OriginalFile) {
121    assert(!ImplicitIncludePTH.empty());
122    fprintf(stderr, "error: PTH file '%s' does not designate an original "
123            "source header file for -include-pth\n",
124            ImplicitIncludePTH.c_str());
125    exit (1);
126  }
127
128  AddImplicitInclude(Buf, OriginalFile);
129}
130
131/// PickFP - This is used to pick a value based on the FP semantics of the
132/// specified FP model.
133template <typename T>
134static T PickFP(const llvm::fltSemantics *Sem, T IEEESingleVal,
135                T IEEEDoubleVal, T X87DoubleExtendedVal, T PPCDoubleDoubleVal,
136                T IEEEQuadVal) {
137  if (Sem == (const llvm::fltSemantics*)&llvm::APFloat::IEEEsingle)
138    return IEEESingleVal;
139  if (Sem == (const llvm::fltSemantics*)&llvm::APFloat::IEEEdouble)
140    return IEEEDoubleVal;
141  if (Sem == (const llvm::fltSemantics*)&llvm::APFloat::x87DoubleExtended)
142    return X87DoubleExtendedVal;
143  if (Sem == (const llvm::fltSemantics*)&llvm::APFloat::PPCDoubleDouble)
144    return PPCDoubleDoubleVal;
145  assert(Sem == (const llvm::fltSemantics*)&llvm::APFloat::IEEEquad);
146  return IEEEQuadVal;
147}
148
149static void DefineFloatMacros(std::vector<char> &Buf, const char *Prefix,
150                              const llvm::fltSemantics *Sem) {
151  const char *DenormMin, *Epsilon, *Max, *Min;
152  DenormMin = PickFP(Sem, "1.40129846e-45F", "4.9406564584124654e-324",
153                     "3.64519953188247460253e-4951L",
154                     "4.94065645841246544176568792868221e-324L",
155                     "6.47517511943802511092443895822764655e-4966L");
156  int Digits = PickFP(Sem, 6, 15, 18, 31, 33);
157  Epsilon = PickFP(Sem, "1.19209290e-7F", "2.2204460492503131e-16",
158                   "1.08420217248550443401e-19L",
159                   "4.94065645841246544176568792868221e-324L",
160                   "1.92592994438723585305597794258492732e-34L");
161  int HasInifinity = 1, HasQuietNaN = 1;
162  int MantissaDigits = PickFP(Sem, 24, 53, 64, 106, 113);
163  int Min10Exp = PickFP(Sem, -37, -307, -4931, -291, -4931);
164  int Max10Exp = PickFP(Sem, 38, 308, 4932, 308, 4932);
165  int MinExp = PickFP(Sem, -125, -1021, -16381, -968, -16381);
166  int MaxExp = PickFP(Sem, 128, 1024, 16384, 1024, 16384);
167  Min = PickFP(Sem, "1.17549435e-38F", "2.2250738585072014e-308",
168               "3.36210314311209350626e-4932L",
169               "2.00416836000897277799610805135016e-292L",
170               "3.36210314311209350626267781732175260e-4932L");
171  Max = PickFP(Sem, "3.40282347e+38F", "1.7976931348623157e+308",
172               "1.18973149535723176502e+4932L",
173               "1.79769313486231580793728971405301e+308L",
174               "1.18973149535723176508575932662800702e+4932L");
175
176  char MacroBuf[100];
177  sprintf(MacroBuf, "__%s_DENORM_MIN__=%s", Prefix, DenormMin);
178  DefineBuiltinMacro(Buf, MacroBuf);
179  sprintf(MacroBuf, "__%s_DIG__=%d", Prefix, Digits);
180  DefineBuiltinMacro(Buf, MacroBuf);
181  sprintf(MacroBuf, "__%s_EPSILON__=%s", Prefix, Epsilon);
182  DefineBuiltinMacro(Buf, MacroBuf);
183  sprintf(MacroBuf, "__%s_HAS_INFINITY__=%d", Prefix, HasInifinity);
184  DefineBuiltinMacro(Buf, MacroBuf);
185  sprintf(MacroBuf, "__%s_HAS_QUIET_NAN__=%d", Prefix, HasQuietNaN);
186  DefineBuiltinMacro(Buf, MacroBuf);
187  sprintf(MacroBuf, "__%s_MANT_DIG__=%d", Prefix, MantissaDigits);
188  DefineBuiltinMacro(Buf, MacroBuf);
189  sprintf(MacroBuf, "__%s_MAX_10_EXP__=%d", Prefix, Max10Exp);
190  DefineBuiltinMacro(Buf, MacroBuf);
191  sprintf(MacroBuf, "__%s_MAX_EXP__=%d", Prefix, MaxExp);
192  DefineBuiltinMacro(Buf, MacroBuf);
193  sprintf(MacroBuf, "__%s_MAX__=%s", Prefix, Max);
194  DefineBuiltinMacro(Buf, MacroBuf);
195  sprintf(MacroBuf, "__%s_MIN_10_EXP__=(%d)", Prefix, Min10Exp);
196  DefineBuiltinMacro(Buf, MacroBuf);
197  sprintf(MacroBuf, "__%s_MIN_EXP__=(%d)", Prefix, MinExp);
198  DefineBuiltinMacro(Buf, MacroBuf);
199  sprintf(MacroBuf, "__%s_MIN__=%s", Prefix, Min);
200  DefineBuiltinMacro(Buf, MacroBuf);
201  sprintf(MacroBuf, "__%s_HAS_DENORM__=1", Prefix);
202  DefineBuiltinMacro(Buf, MacroBuf);
203}
204
205
206/// DefineTypeSize - Emit a macro to the predefines buffer that declares a macro
207/// named MacroName with the max value for a type with width 'TypeWidth' a
208/// signedness of 'isSigned' and with a value suffix of 'ValSuffix' (e.g. LL).
209static void DefineTypeSize(const char *MacroName, unsigned TypeWidth,
210                           const char *ValSuffix, bool isSigned,
211                           std::vector<char> &Buf) {
212  char MacroBuf[60];
213  long long MaxVal;
214  if (isSigned)
215    MaxVal = (1LL << (TypeWidth - 1)) - 1;
216  else
217    MaxVal = ~0LL >> (64-TypeWidth);
218
219  // FIXME: Switch to using raw_ostream and avoid utostr().
220  sprintf(MacroBuf, "%s=%s%s", MacroName, llvm::utostr(MaxVal).c_str(),
221          ValSuffix);
222  DefineBuiltinMacro(Buf, MacroBuf);
223}
224
225/// DefineTypeSize - An overloaded helper that uses TargetInfo to determine
226/// the width, suffix, and signedness of the given type
227static void DefineTypeSize(const char *MacroName, TargetInfo::IntType Ty,
228                           const TargetInfo &TI, std::vector<char> &Buf) {
229  DefineTypeSize(MacroName, TI.getTypeWidth(Ty), TI.getTypeConstantSuffix(Ty),
230                 TI.isTypeSigned(Ty), Buf);
231}
232
233static void DefineType(const char *MacroName, TargetInfo::IntType Ty,
234                       std::vector<char> &Buf) {
235  char MacroBuf[60];
236  sprintf(MacroBuf, "%s=%s", MacroName, TargetInfo::getTypeName(Ty));
237  DefineBuiltinMacro(Buf, MacroBuf);
238}
239
240static void DefineTypeWidth(const char *MacroName, TargetInfo::IntType Ty,
241                            const TargetInfo &TI, std::vector<char> &Buf) {
242  char MacroBuf[60];
243  sprintf(MacroBuf, "%s=%d", MacroName, TI.getTypeWidth(Ty));
244  DefineBuiltinMacro(Buf, MacroBuf);
245}
246
247static void DefineExactWidthIntType(TargetInfo::IntType Ty,
248                               const TargetInfo &TI, std::vector<char> &Buf) {
249  char MacroBuf[60];
250  int TypeWidth = TI.getTypeWidth(Ty);
251  sprintf(MacroBuf, "__INT%d_TYPE__", TypeWidth);
252  DefineType(MacroBuf, Ty, Buf);
253
254
255  const char *ConstSuffix = TargetInfo::getTypeConstantSuffix(Ty);
256  if (strlen(ConstSuffix) > 0) {
257    sprintf(MacroBuf, "__INT%d_C_SUFFIX__=%s", TypeWidth, ConstSuffix);
258    DefineBuiltinMacro(Buf, MacroBuf);
259  }
260}
261
262static void InitializePredefinedMacros(const TargetInfo &TI,
263                                       const LangOptions &LangOpts,
264                                       std::vector<char> &Buf) {
265  char MacroBuf[60];
266  // Compiler version introspection macros.
267  DefineBuiltinMacro(Buf, "__llvm__=1");   // LLVM Backend
268  DefineBuiltinMacro(Buf, "__clang__=1");  // Clang Frontend
269
270  // Currently claim to be compatible with GCC 4.2.1-5621.
271  DefineBuiltinMacro(Buf, "__GNUC_MINOR__=2");
272  DefineBuiltinMacro(Buf, "__GNUC_PATCHLEVEL__=1");
273  DefineBuiltinMacro(Buf, "__GNUC__=4");
274  DefineBuiltinMacro(Buf, "__GXX_ABI_VERSION=1002");
275  DefineBuiltinMacro(Buf, "__VERSION__=\"4.2.1 Compatible Clang Compiler\"");
276
277
278  // Initialize language-specific preprocessor defines.
279
280  // These should all be defined in the preprocessor according to the
281  // current language configuration.
282  if (!LangOpts.Microsoft)
283    DefineBuiltinMacro(Buf, "__STDC__=1");
284  if (LangOpts.AsmPreprocessor)
285    DefineBuiltinMacro(Buf, "__ASSEMBLER__=1");
286
287  if (!LangOpts.CPlusPlus) {
288    if (LangOpts.C99)
289      DefineBuiltinMacro(Buf, "__STDC_VERSION__=199901L");
290    else if (!LangOpts.GNUMode && LangOpts.Digraphs)
291      DefineBuiltinMacro(Buf, "__STDC_VERSION__=199409L");
292  }
293
294  // Standard conforming mode?
295  if (!LangOpts.GNUMode)
296    DefineBuiltinMacro(Buf, "__STRICT_ANSI__=1");
297
298  if (LangOpts.CPlusPlus0x)
299    DefineBuiltinMacro(Buf, "__GXX_EXPERIMENTAL_CXX0X__");
300
301  if (LangOpts.Freestanding)
302    DefineBuiltinMacro(Buf, "__STDC_HOSTED__=0");
303  else
304    DefineBuiltinMacro(Buf, "__STDC_HOSTED__=1");
305
306  if (LangOpts.ObjC1) {
307    DefineBuiltinMacro(Buf, "__OBJC__=1");
308    if (LangOpts.ObjCNonFragileABI) {
309      DefineBuiltinMacro(Buf, "__OBJC2__=1");
310      DefineBuiltinMacro(Buf, "OBJC_ZEROCOST_EXCEPTIONS=1");
311    }
312
313    if (LangOpts.getGCMode() != LangOptions::NonGC)
314      DefineBuiltinMacro(Buf, "__OBJC_GC__=1");
315
316    if (LangOpts.NeXTRuntime)
317      DefineBuiltinMacro(Buf, "__NEXT_RUNTIME__=1");
318  }
319
320  // darwin_constant_cfstrings controls this. This is also dependent
321  // on other things like the runtime I believe.  This is set even for C code.
322  DefineBuiltinMacro(Buf, "__CONSTANT_CFSTRINGS__=1");
323
324  if (LangOpts.ObjC2)
325    DefineBuiltinMacro(Buf, "OBJC_NEW_PROPERTIES");
326
327  if (LangOpts.PascalStrings)
328    DefineBuiltinMacro(Buf, "__PASCAL_STRINGS__");
329
330  if (LangOpts.Blocks) {
331    DefineBuiltinMacro(Buf, "__block=__attribute__((__blocks__(byref)))");
332    DefineBuiltinMacro(Buf, "__BLOCKS__=1");
333  }
334
335  if (LangOpts.Exceptions)
336    DefineBuiltinMacro(Buf, "__EXCEPTIONS=1");
337
338  if (LangOpts.CPlusPlus) {
339    DefineBuiltinMacro(Buf, "__DEPRECATED=1");
340    DefineBuiltinMacro(Buf, "__GNUG__=4");
341    DefineBuiltinMacro(Buf, "__GXX_WEAK__=1");
342    if (LangOpts.GNUMode)
343      DefineBuiltinMacro(Buf, "__cplusplus=1");
344    else
345      // C++ [cpp.predefined]p1:
346      //   The name_ _cplusplusis defined to the value199711Lwhen compiling a
347      //   C++ translation unit.
348      DefineBuiltinMacro(Buf, "__cplusplus=199711L");
349    DefineBuiltinMacro(Buf, "__private_extern__=extern");
350    // Ugly hack to work with GNU libstdc++.
351    DefineBuiltinMacro(Buf, "_GNU_SOURCE=1");
352  }
353
354  if (LangOpts.Microsoft) {
355    // Filter out some microsoft extensions when trying to parse in ms-compat
356    // mode.
357    DefineBuiltinMacro(Buf, "__int8=__INT8_TYPE__");
358    DefineBuiltinMacro(Buf, "__int16=__INT16_TYPE__");
359    DefineBuiltinMacro(Buf, "__int32=__INT32_TYPE__");
360    DefineBuiltinMacro(Buf, "__int64=__INT64_TYPE__");
361    // Work around some issues with Visual C++ headerws.
362    if (LangOpts.CPlusPlus) {
363      // Since we define wchar_t in C++ mode.
364      DefineBuiltinMacro(Buf, "_WCHAR_T_DEFINED=1");
365      DefineBuiltinMacro(Buf, "_NATIVE_WCHAR_T_DEFINED=1");
366      // FIXME:  This should be temporary until we have a __pragma
367      // solution, to avoid some errors flagged in VC++ headers.
368      DefineBuiltinMacro(Buf, "_CRT_SECURE_CPP_OVERLOAD_SECURE_NAMES=0");
369    }
370  }
371
372  if (LangOpts.Optimize)
373    DefineBuiltinMacro(Buf, "__OPTIMIZE__=1");
374  if (LangOpts.OptimizeSize)
375    DefineBuiltinMacro(Buf, "__OPTIMIZE_SIZE__=1");
376
377  // Initialize target-specific preprocessor defines.
378
379  // Define type sizing macros based on the target properties.
380  assert(TI.getCharWidth() == 8 && "Only support 8-bit char so far");
381  DefineBuiltinMacro(Buf, "__CHAR_BIT__=8");
382
383  DefineTypeSize("__SCHAR_MAX__", TI.getCharWidth(), "", true, Buf);
384  DefineTypeSize("__SHRT_MAX__", TargetInfo::SignedShort, TI, Buf);
385  DefineTypeSize("__INT_MAX__", TargetInfo::SignedInt, TI, Buf);
386  DefineTypeSize("__LONG_MAX__", TargetInfo::SignedLong, TI, Buf);
387  DefineTypeSize("__LONG_LONG_MAX__", TargetInfo::SignedLongLong, TI, Buf);
388  DefineTypeSize("__WCHAR_MAX__", TI.getWCharType(), TI, Buf);
389  DefineTypeSize("__INTMAX_MAX__", TI.getIntMaxType(), TI, Buf);
390
391  DefineType("__INTMAX_TYPE__", TI.getIntMaxType(), Buf);
392  DefineType("__UINTMAX_TYPE__", TI.getUIntMaxType(), Buf);
393  DefineTypeWidth("__INTMAX_WIDTH__",  TI.getIntMaxType(), TI, Buf);
394  DefineType("__PTRDIFF_TYPE__", TI.getPtrDiffType(0), Buf);
395  DefineType("__INTPTR_TYPE__", TI.getIntPtrType(), Buf);
396  DefineType("__SIZE_TYPE__", TI.getSizeType(), Buf);
397  DefineType("__WCHAR_TYPE__", TI.getWCharType(), Buf);
398  DefineType("__WINT_TYPE__", TI.getWIntType(), Buf);
399
400  DefineFloatMacros(Buf, "FLT", &TI.getFloatFormat());
401  DefineFloatMacros(Buf, "DBL", &TI.getDoubleFormat());
402  DefineFloatMacros(Buf, "LDBL", &TI.getLongDoubleFormat());
403
404  // Define a __POINTER_WIDTH__ macro for stdint.h.
405  sprintf(MacroBuf, "__POINTER_WIDTH__=%d", (int)TI.getPointerWidth(0));
406  DefineBuiltinMacro(Buf, MacroBuf);
407
408  if (!LangOpts.CharIsSigned)
409    DefineBuiltinMacro(Buf, "__CHAR_UNSIGNED__");
410
411  // Define exact-width integer types for stdint.h
412  sprintf(MacroBuf, "__INT%d_TYPE__=char", TI.getCharWidth());
413  DefineBuiltinMacro(Buf, MacroBuf);
414
415  if (TI.getShortWidth() > TI.getCharWidth())
416    DefineExactWidthIntType(TargetInfo::SignedShort, TI, Buf);
417
418  if (TI.getIntWidth() > TI.getShortWidth())
419    DefineExactWidthIntType(TargetInfo::SignedInt, TI, Buf);
420
421  if (TI.getLongWidth() > TI.getIntWidth())
422    DefineExactWidthIntType(TargetInfo::SignedLong, TI, Buf);
423
424  if (TI.getLongLongWidth() > TI.getLongWidth())
425    DefineExactWidthIntType(TargetInfo::SignedLongLong, TI, Buf);
426
427  // Add __builtin_va_list typedef.
428  {
429    const char *VAList = TI.getVAListDeclaration();
430    Buf.insert(Buf.end(), VAList, VAList+strlen(VAList));
431    Buf.push_back('\n');
432  }
433
434  if (const char *Prefix = TI.getUserLabelPrefix()) {
435    sprintf(MacroBuf, "__USER_LABEL_PREFIX__=%s", Prefix);
436    DefineBuiltinMacro(Buf, MacroBuf);
437  }
438
439  // Build configuration options.  FIXME: these should be controlled by
440  // command line options or something.
441  DefineBuiltinMacro(Buf, "__FINITE_MATH_ONLY__=0");
442
443  if (LangOpts.GNUInline)
444    DefineBuiltinMacro(Buf, "__GNUC_GNU_INLINE__=1");
445  else
446    DefineBuiltinMacro(Buf, "__GNUC_STDC_INLINE__=1");
447
448  if (LangOpts.NoInline)
449    DefineBuiltinMacro(Buf, "__NO_INLINE__=1");
450
451  if (unsigned PICLevel = LangOpts.PICLevel) {
452    sprintf(MacroBuf, "__PIC__=%d", PICLevel);
453    DefineBuiltinMacro(Buf, MacroBuf);
454
455    sprintf(MacroBuf, "__pic__=%d", PICLevel);
456    DefineBuiltinMacro(Buf, MacroBuf);
457  }
458
459  // Macros to control C99 numerics and <float.h>
460  DefineBuiltinMacro(Buf, "__FLT_EVAL_METHOD__=0");
461  DefineBuiltinMacro(Buf, "__FLT_RADIX__=2");
462  sprintf(MacroBuf, "__DECIMAL_DIG__=%d",
463          PickFP(&TI.getLongDoubleFormat(), -1/*FIXME*/, 17, 21, 33, 36));
464  DefineBuiltinMacro(Buf, MacroBuf);
465
466  if (LangOpts.getStackProtectorMode() == LangOptions::SSPOn)
467    DefineBuiltinMacro(Buf, "__SSP__=1");
468  else if (LangOpts.getStackProtectorMode() == LangOptions::SSPReq)
469    DefineBuiltinMacro(Buf, "__SSP_ALL__=2");
470
471  // Get other target #defines.
472  TI.getTargetDefines(LangOpts, Buf);
473}
474
475/// InitializePreprocessor - Initialize the preprocessor getting it and the
476/// environment ready to process a single file. This returns true on error.
477///
478void clang::InitializePreprocessor(Preprocessor &PP,
479                                   const PreprocessorOptions &InitOpts,
480                                   const HeaderSearchOptions &HSOpts) {
481  std::vector<char> PredefineBuffer;
482
483  const char *LineDirective = "# 1 \"<built-in>\" 3\n";
484  PredefineBuffer.insert(PredefineBuffer.end(),
485                         LineDirective, LineDirective+strlen(LineDirective));
486
487  // Install things like __POWERPC__, __GNUC__, etc into the macro table.
488  if (InitOpts.UsePredefines)
489    InitializePredefinedMacros(PP.getTargetInfo(), PP.getLangOptions(),
490                               PredefineBuffer);
491
492  // Add on the predefines from the driver.  Wrap in a #line directive to report
493  // that they come from the command line.
494  LineDirective = "# 1 \"<command line>\" 1\n";
495  PredefineBuffer.insert(PredefineBuffer.end(),
496                         LineDirective, LineDirective+strlen(LineDirective));
497
498  // Process #define's and #undef's in the order they are given.
499  for (unsigned i = 0, e = InitOpts.Macros.size(); i != e; ++i) {
500    if (InitOpts.Macros[i].second)  // isUndef
501      UndefineBuiltinMacro(PredefineBuffer, InitOpts.Macros[i].first.c_str());
502    else
503      DefineBuiltinMacro(PredefineBuffer, InitOpts.Macros[i].first.c_str());
504  }
505
506  // If -imacros are specified, include them now.  These are processed before
507  // any -include directives.
508  for (unsigned i = 0, e = InitOpts.MacroIncludes.size(); i != e; ++i)
509    AddImplicitIncludeMacros(PredefineBuffer, InitOpts.MacroIncludes[i]);
510
511  // Process -include directives.
512  for (unsigned i = 0, e = InitOpts.Includes.size(); i != e; ++i) {
513    const std::string &Path = InitOpts.Includes[i];
514    if (Path == InitOpts.ImplicitPTHInclude)
515      AddImplicitIncludePTH(PredefineBuffer, PP, Path);
516    else
517      AddImplicitInclude(PredefineBuffer, Path);
518  }
519
520  // Null terminate PredefinedBuffer and add it.
521  PredefineBuffer.push_back(0);
522  PP.setPredefines(&PredefineBuffer[0]);
523
524  // Initialize the header search object.
525  ApplyHeaderSearchOptions(PP.getHeaderSearchInfo(), HSOpts,
526                           PP.getLangOptions(),
527                           PP.getTargetInfo().getTriple());
528}
529