xref: /llvm-project/clang/lib/Frontend/InitPreprocessor.cpp (revision 97eec24b0bc245fc96ac9615899c3d15a6bc8b3e)
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"
28 using 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=".
33 static void DefineBuiltinMacro(MacroBuilder &Builder, StringRef Macro,
34                                Diagnostic &Diags) {
35   std::pair<StringRef, StringRef> MacroPair = Macro.split('=');
36   StringRef MacroName = MacroPair.first;
37   StringRef MacroBody = MacroPair.second;
38   if (MacroName.size() != Macro.size()) {
39     // Per GCC -D semantics, the macro ends at \n if it exists.
40     StringRef::size_type End = MacroBody.find_first_of("\n\r");
41     if (End != 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 
51 std::string clang::NormalizeDashIncludePath(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.
73 static void AddImplicitInclude(MacroBuilder &Builder, StringRef File,
74                                FileManager &FileMgr) {
75   Builder.append("#include \"" +
76                  Twine(NormalizeDashIncludePath(File, FileMgr)) + "\"");
77 }
78 
79 static void AddImplicitIncludeMacros(MacroBuilder &Builder,
80                                      StringRef File,
81                                      FileManager &FileMgr) {
82   Builder.append("#__include_macros \"" +
83                  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.
90 static void AddImplicitIncludePTH(MacroBuilder &Builder, Preprocessor &PP,
91                                   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.
107 template <typename T>
108 static 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 
123 static void DefineFloatMacros(MacroBuilder &Builder, 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__", Twine(Digits));
157   Builder.defineMacro(DefPrefix + "EPSILON__", Twine(Epsilon));
158   Builder.defineMacro(DefPrefix + "HAS_INFINITY__");
159   Builder.defineMacro(DefPrefix + "HAS_QUIET_NAN__");
160   Builder.defineMacro(DefPrefix + "MANT_DIG__", Twine(MantissaDigits));
161 
162   Builder.defineMacro(DefPrefix + "MAX_10_EXP__", Twine(Max10Exp));
163   Builder.defineMacro(DefPrefix + "MAX_EXP__", Twine(MaxExp));
164   Builder.defineMacro(DefPrefix + "MAX__", Twine(Max));
165 
166   Builder.defineMacro(DefPrefix + "MIN_10_EXP__","("+Twine(Min10Exp)+")");
167   Builder.defineMacro(DefPrefix + "MIN_EXP__", "("+Twine(MinExp)+")");
168   Builder.defineMacro(DefPrefix + "MIN__", 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).
175 static void DefineTypeSize(StringRef MacroName, unsigned TypeWidth,
176                            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
185 static void DefineTypeSize(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 
191 static void DefineType(const Twine &MacroName, TargetInfo::IntType Ty,
192                        MacroBuilder &Builder) {
193   Builder.defineMacro(MacroName, TargetInfo::getTypeName(Ty));
194 }
195 
196 static void DefineTypeWidth(StringRef MacroName, TargetInfo::IntType Ty,
197                             const TargetInfo &TI, MacroBuilder &Builder) {
198   Builder.defineMacro(MacroName, Twine(TI.getTypeWidth(Ty)));
199 }
200 
201 static void DefineTypeSizeof(StringRef MacroName, unsigned BitWidth,
202                              const TargetInfo &TI, MacroBuilder &Builder) {
203   Builder.defineMacro(MacroName,
204                       Twine(BitWidth / TI.getCharWidth()));
205 }
206 
207 static 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" + Twine(TypeWidth) + "_TYPE__", Ty, Builder);
217 
218   StringRef ConstSuffix(TargetInfo::getTypeConstantSuffix(Ty));
219   if (!ConstSuffix.empty())
220     Builder.defineMacro("__INT" + Twine(TypeWidth) + "_C_SUFFIX__",
221                         ConstSuffix);
222 }
223 
224 /// \brief Add definitions required for a smooth interaction between
225 /// Objective-C++ automatic reference counting and libc++.
226 static void AddObjCXXARCLibcxxDefines(const LangOptions &LangOpts,
227                                       MacroBuilder &Builder) {
228   Builder.defineMacro("_LIBCPP_PREDEFINED_OBJC_ARC_ADDRESSOF");
229 
230   std::string Result;
231   {
232     // Provide overloads of the function std::__1::addressof() that accept
233     // references to lifetime-qualified objects. libc++'s (more general)
234     // std::__1::addressof() template fails to instantiate with such types,
235     // because it attempts to convert the object to a char& before
236     // dereferencing.
237     llvm::raw_string_ostream Out(Result);
238 
239     Out << "#pragma clang diagnostic push\n"
240         << "#pragma clang diagnostic ignored \"-Wc++0x-extensions\"\n"
241         << "namespace std { inline namespace __1 {\n"
242         << "\n";
243 
244     Out << "template <class _Tp>\n"
245         << "inline __attribute__ ((__visibility__(\"hidden\"), "
246         << "__always_inline__))\n"
247         << "__attribute__((objc_ownership(strong))) _Tp*\n"
248         << "addressof(__attribute__((objc_ownership(strong))) _Tp& __x) {\n"
249         << "  return &__x;\n"
250         << "}\n"
251         << "\n";
252 
253     if (LangOpts.ObjCRuntimeHasWeak) {
254       Out << "template <class _Tp>\n"
255           << "inline __attribute__ ((__visibility__(\"hidden\"),"
256           << "__always_inline__))\n"
257           << "__attribute__((objc_ownership(weak))) _Tp*\n"
258           << "addressof(__attribute__((objc_ownership(weak))) _Tp& __x) {\n"
259           << "  return &__x;\n"
260           << "};\n"
261           << "\n";
262     }
263 
264     Out << "template <class _Tp>\n"
265         << "inline __attribute__ ((__visibility__(\"hidden\"),"
266         << "__always_inline__))\n"
267         << "__attribute__((objc_ownership(autoreleasing))) _Tp*\n"
268         << "addressof(__attribute__((objc_ownership(autoreleasing))) _Tp& __x) "
269         << "{\n"
270         << " return &__x;\n"
271         << "}\n"
272         << "\n";
273 
274     Out << "template <class _Tp>\n"
275         << "inline __attribute__ ((__visibility__(\"hidden\"), "
276         << "__always_inline__))\n"
277         << "__unsafe_unretained _Tp* addressof(__unsafe_unretained _Tp& __x)"
278         << " {\n"
279         << "  return &__x;\n"
280         << "}\n";
281 
282     Out << "\n"
283         << "} }\n"
284         << "#pragma clang diagnostic pop\n"
285         << "\n";
286   }
287   Builder.append(Result);
288 }
289 
290 /// \brief Add definitions required for a smooth interaction between
291 /// Objective-C++ automated reference counting and libstdc++ (4.2).
292 static void AddObjCXXARCLibstdcxxDefines(const LangOptions &LangOpts,
293                                          MacroBuilder &Builder) {
294   Builder.defineMacro("_GLIBCXX_PREDEFINED_OBJC_ARC_IS_SCALAR");
295 
296   std::string Result;
297   {
298     // Provide specializations for the __is_scalar type trait so that
299     // lifetime-qualified objects are not considered "scalar" types, which
300     // libstdc++ uses as an indicator of the presence of trivial copy, assign,
301     // default-construct, and destruct semantics (none of which hold for
302     // lifetime-qualified objects in ARC).
303     llvm::raw_string_ostream Out(Result);
304 
305     Out << "namespace std {\n"
306         << "\n"
307         << "struct __true_type;\n"
308         << "struct __false_type;\n"
309         << "\n";
310 
311     Out << "template<typename _Tp> struct __is_scalar;\n"
312         << "\n";
313 
314     Out << "template<typename _Tp>\n"
315         << "struct __is_scalar<__attribute__((objc_ownership(strong))) _Tp> {\n"
316         << "  enum { __value = 0 };\n"
317         << "  typedef __false_type __type;\n"
318         << "};\n"
319         << "\n";
320 
321     if (LangOpts.ObjCRuntimeHasWeak) {
322       Out << "template<typename _Tp>\n"
323           << "struct __is_scalar<__attribute__((objc_ownership(weak))) _Tp> {\n"
324           << "  enum { __value = 0 };\n"
325           << "  typedef __false_type __type;\n"
326           << "};\n"
327           << "\n";
328     }
329 
330     Out << "template<typename _Tp>\n"
331         << "struct __is_scalar<__attribute__((objc_ownership(autoreleasing)))"
332         << " _Tp> {\n"
333         << "  enum { __value = 0 };\n"
334         << "  typedef __false_type __type;\n"
335         << "};\n"
336         << "\n";
337 
338     Out << "}\n";
339   }
340   Builder.append(Result);
341 }
342 
343 static void InitializeStandardPredefinedMacros(const TargetInfo &TI,
344                                                const LangOptions &LangOpts,
345                                                const FrontendOptions &FEOpts,
346                                                MacroBuilder &Builder) {
347   if (!LangOpts.Microsoft && !LangOpts.TraditionalCPP)
348     Builder.defineMacro("__STDC__");
349   if (LangOpts.Freestanding)
350     Builder.defineMacro("__STDC_HOSTED__", "0");
351   else
352     Builder.defineMacro("__STDC_HOSTED__");
353 
354   if (!LangOpts.CPlusPlus) {
355     if (LangOpts.C99)
356       Builder.defineMacro("__STDC_VERSION__", "199901L");
357     else if (!LangOpts.GNUMode && LangOpts.Digraphs)
358       Builder.defineMacro("__STDC_VERSION__", "199409L");
359   } else {
360     if (LangOpts.GNUMode)
361       Builder.defineMacro("__cplusplus");
362     else {
363       // C++0x [cpp.predefined]p1:
364       //   The name_ _cplusplus is defined to the value 201103L when compiling a
365       //   C++ translation unit.
366       if (LangOpts.CPlusPlus0x)
367         Builder.defineMacro("__cplusplus", "201103L");
368       // C++03 [cpp.predefined]p1:
369       //   The name_ _cplusplus is defined to the value 199711L when compiling a
370       //   C++ translation unit.
371       else
372         Builder.defineMacro("__cplusplus", "199711L");
373     }
374   }
375 
376   if (LangOpts.ObjC1)
377     Builder.defineMacro("__OBJC__");
378 
379   // Not "standard" per se, but available even with the -undef flag.
380   if (LangOpts.AsmPreprocessor)
381     Builder.defineMacro("__ASSEMBLER__");
382 }
383 
384 static void InitializePredefinedMacros(const TargetInfo &TI,
385                                        const LangOptions &LangOpts,
386                                        const FrontendOptions &FEOpts,
387                                        MacroBuilder &Builder) {
388   // Compiler version introspection macros.
389   Builder.defineMacro("__llvm__");  // LLVM Backend
390   Builder.defineMacro("__clang__"); // Clang Frontend
391 #define TOSTR2(X) #X
392 #define TOSTR(X) TOSTR2(X)
393   Builder.defineMacro("__clang_major__", TOSTR(CLANG_VERSION_MAJOR));
394   Builder.defineMacro("__clang_minor__", TOSTR(CLANG_VERSION_MINOR));
395 #ifdef CLANG_VERSION_PATCHLEVEL
396   Builder.defineMacro("__clang_patchlevel__", TOSTR(CLANG_VERSION_PATCHLEVEL));
397 #else
398   Builder.defineMacro("__clang_patchlevel__", "0");
399 #endif
400   Builder.defineMacro("__clang_version__",
401                       "\"" CLANG_VERSION_STRING " ("
402                       + getClangFullRepositoryVersion() + ")\"");
403 #undef TOSTR
404 #undef TOSTR2
405   // Currently claim to be compatible with GCC 4.2.1-5621.
406   Builder.defineMacro("__GNUC_MINOR__", "2");
407   Builder.defineMacro("__GNUC_PATCHLEVEL__", "1");
408   Builder.defineMacro("__GNUC__", "4");
409   Builder.defineMacro("__GXX_ABI_VERSION", "1002");
410 
411   // As sad as it is, enough software depends on the __VERSION__ for version
412   // checks that it is necessary to report 4.2.1 (the base GCC version we claim
413   // compatibility with) first.
414   Builder.defineMacro("__VERSION__", "\"4.2.1 Compatible " +
415                       Twine(getClangFullCPPVersion()) + "\"");
416 
417   // Initialize language-specific preprocessor defines.
418 
419   // Standard conforming mode?
420   if (!LangOpts.GNUMode)
421     Builder.defineMacro("__STRICT_ANSI__");
422 
423   if (LangOpts.CPlusPlus0x)
424     Builder.defineMacro("__GXX_EXPERIMENTAL_CXX0X__");
425 
426   if (LangOpts.ObjC1) {
427     if (LangOpts.ObjCNonFragileABI) {
428       Builder.defineMacro("__OBJC2__");
429 
430       if (LangOpts.ObjCExceptions)
431         Builder.defineMacro("OBJC_ZEROCOST_EXCEPTIONS");
432     }
433 
434     if (LangOpts.getGC() != LangOptions::NonGC)
435       Builder.defineMacro("__OBJC_GC__");
436 
437     if (LangOpts.NeXTRuntime)
438       Builder.defineMacro("__NEXT_RUNTIME__");
439   }
440 
441   // darwin_constant_cfstrings controls this. This is also dependent
442   // on other things like the runtime I believe.  This is set even for C code.
443   if (!LangOpts.NoConstantCFStrings)
444       Builder.defineMacro("__CONSTANT_CFSTRINGS__");
445 
446   if (LangOpts.ObjC2)
447     Builder.defineMacro("OBJC_NEW_PROPERTIES");
448 
449   if (LangOpts.PascalStrings)
450     Builder.defineMacro("__PASCAL_STRINGS__");
451 
452   if (LangOpts.Blocks) {
453     Builder.defineMacro("__block", "__attribute__((__blocks__(byref)))");
454     Builder.defineMacro("__BLOCKS__");
455   }
456 
457   if (LangOpts.CXXExceptions)
458     Builder.defineMacro("__EXCEPTIONS");
459   if (LangOpts.RTTI)
460     Builder.defineMacro("__GXX_RTTI");
461   if (LangOpts.SjLjExceptions)
462     Builder.defineMacro("__USING_SJLJ_EXCEPTIONS__");
463 
464   if (LangOpts.Deprecated)
465     Builder.defineMacro("__DEPRECATED");
466 
467   if (LangOpts.CPlusPlus) {
468     Builder.defineMacro("__GNUG__", "4");
469     Builder.defineMacro("__GXX_WEAK__");
470     Builder.defineMacro("__private_extern__", "extern");
471   }
472 
473   if (LangOpts.Microsoft) {
474     // Both __PRETTY_FUNCTION__ and __FUNCTION__ are GCC extensions, however
475     // VC++ appears to only like __FUNCTION__.
476     Builder.defineMacro("__PRETTY_FUNCTION__", "__FUNCTION__");
477     // Work around some issues with Visual C++ headerws.
478     if (LangOpts.CPlusPlus) {
479       // Since we define wchar_t in C++ mode.
480       Builder.defineMacro("_WCHAR_T_DEFINED");
481       Builder.defineMacro("_NATIVE_WCHAR_T_DEFINED");
482       // FIXME: Support Microsoft's __identifier extension in the lexer.
483       Builder.append("#define __identifier(x) x");
484       Builder.append("class type_info;");
485     }
486 
487     if (LangOpts.CPlusPlus0x) {
488       Builder.defineMacro("_HAS_CHAR16_T_LANGUAGE_SUPPORT", "1");
489     }
490   }
491 
492   if (LangOpts.Optimize)
493     Builder.defineMacro("__OPTIMIZE__");
494   if (LangOpts.OptimizeSize)
495     Builder.defineMacro("__OPTIMIZE_SIZE__");
496 
497   // Initialize target-specific preprocessor defines.
498 
499   // Define type sizing macros based on the target properties.
500   assert(TI.getCharWidth() == 8 && "Only support 8-bit char so far");
501   Builder.defineMacro("__CHAR_BIT__", "8");
502 
503   DefineTypeSize("__SCHAR_MAX__", TI.getCharWidth(), "", true, Builder);
504   DefineTypeSize("__SHRT_MAX__", TargetInfo::SignedShort, TI, Builder);
505   DefineTypeSize("__INT_MAX__", TargetInfo::SignedInt, TI, Builder);
506   DefineTypeSize("__LONG_MAX__", TargetInfo::SignedLong, TI, Builder);
507   DefineTypeSize("__LONG_LONG_MAX__", TargetInfo::SignedLongLong, TI, Builder);
508   DefineTypeSize("__WCHAR_MAX__", TI.getWCharType(), TI, Builder);
509   DefineTypeSize("__INTMAX_MAX__", TI.getIntMaxType(), TI, Builder);
510 
511   DefineTypeSizeof("__SIZEOF_DOUBLE__", TI.getDoubleWidth(), TI, Builder);
512   DefineTypeSizeof("__SIZEOF_FLOAT__", TI.getFloatWidth(), TI, Builder);
513   DefineTypeSizeof("__SIZEOF_INT__", TI.getIntWidth(), TI, Builder);
514   DefineTypeSizeof("__SIZEOF_LONG__", TI.getLongWidth(), TI, Builder);
515   DefineTypeSizeof("__SIZEOF_LONG_DOUBLE__",TI.getLongDoubleWidth(),TI,Builder);
516   DefineTypeSizeof("__SIZEOF_LONG_LONG__", TI.getLongLongWidth(), TI, Builder);
517   DefineTypeSizeof("__SIZEOF_POINTER__", TI.getPointerWidth(0), TI, Builder);
518   DefineTypeSizeof("__SIZEOF_SHORT__", TI.getShortWidth(), TI, Builder);
519   DefineTypeSizeof("__SIZEOF_PTRDIFF_T__",
520                    TI.getTypeWidth(TI.getPtrDiffType(0)), TI, Builder);
521   DefineTypeSizeof("__SIZEOF_SIZE_T__",
522                    TI.getTypeWidth(TI.getSizeType()), TI, Builder);
523   DefineTypeSizeof("__SIZEOF_WCHAR_T__",
524                    TI.getTypeWidth(TI.getWCharType()), TI, Builder);
525   DefineTypeSizeof("__SIZEOF_WINT_T__",
526                    TI.getTypeWidth(TI.getWIntType()), TI, Builder);
527 
528   DefineType("__INTMAX_TYPE__", TI.getIntMaxType(), Builder);
529   DefineType("__UINTMAX_TYPE__", TI.getUIntMaxType(), Builder);
530   DefineTypeWidth("__INTMAX_WIDTH__",  TI.getIntMaxType(), TI, Builder);
531   DefineType("__PTRDIFF_TYPE__", TI.getPtrDiffType(0), Builder);
532   DefineTypeWidth("__PTRDIFF_WIDTH__", TI.getPtrDiffType(0), TI, Builder);
533   DefineType("__INTPTR_TYPE__", TI.getIntPtrType(), Builder);
534   DefineTypeWidth("__INTPTR_WIDTH__", TI.getIntPtrType(), TI, Builder);
535   DefineType("__SIZE_TYPE__", TI.getSizeType(), Builder);
536   DefineTypeWidth("__SIZE_WIDTH__", TI.getSizeType(), TI, Builder);
537   DefineType("__WCHAR_TYPE__", TI.getWCharType(), Builder);
538   DefineTypeWidth("__WCHAR_WIDTH__", TI.getWCharType(), TI, Builder);
539   DefineType("__WINT_TYPE__", TI.getWIntType(), Builder);
540   DefineTypeWidth("__WINT_WIDTH__", TI.getWIntType(), TI, Builder);
541   DefineTypeWidth("__SIG_ATOMIC_WIDTH__", TI.getSigAtomicType(), TI, Builder);
542   DefineType("__CHAR16_TYPE__", TI.getChar16Type(), Builder);
543   DefineType("__CHAR32_TYPE__", TI.getChar32Type(), Builder);
544 
545   DefineFloatMacros(Builder, "FLT", &TI.getFloatFormat());
546   DefineFloatMacros(Builder, "DBL", &TI.getDoubleFormat());
547   DefineFloatMacros(Builder, "LDBL", &TI.getLongDoubleFormat());
548 
549   // Define a __POINTER_WIDTH__ macro for stdint.h.
550   Builder.defineMacro("__POINTER_WIDTH__",
551                       Twine((int)TI.getPointerWidth(0)));
552 
553   if (!LangOpts.CharIsSigned)
554     Builder.defineMacro("__CHAR_UNSIGNED__");
555 
556   if (!TargetInfo::isTypeSigned(TI.getWIntType()))
557     Builder.defineMacro("__WINT_UNSIGNED__");
558 
559   if (!TargetInfo::isTypeSigned(TI.getWCharType()))
560     Builder.defineMacro("__WCHAR_UNSIGNED__");
561 
562   // Define exact-width integer types for stdint.h
563   Builder.defineMacro("__INT" + Twine(TI.getCharWidth()) + "_TYPE__",
564                       "char");
565 
566   if (TI.getShortWidth() > TI.getCharWidth())
567     DefineExactWidthIntType(TargetInfo::SignedShort, TI, Builder);
568 
569   if (TI.getIntWidth() > TI.getShortWidth())
570     DefineExactWidthIntType(TargetInfo::SignedInt, TI, Builder);
571 
572   if (TI.getLongWidth() > TI.getIntWidth())
573     DefineExactWidthIntType(TargetInfo::SignedLong, TI, Builder);
574 
575   if (TI.getLongLongWidth() > TI.getLongWidth())
576     DefineExactWidthIntType(TargetInfo::SignedLongLong, TI, Builder);
577 
578   // Add __builtin_va_list typedef.
579   Builder.append(TI.getVAListDeclaration());
580 
581   if (const char *Prefix = TI.getUserLabelPrefix())
582     Builder.defineMacro("__USER_LABEL_PREFIX__", Prefix);
583 
584   // Build configuration options.  FIXME: these should be controlled by
585   // command line options or something.
586   Builder.defineMacro("__FINITE_MATH_ONLY__", "0");
587 
588   if (LangOpts.GNUInline)
589     Builder.defineMacro("__GNUC_GNU_INLINE__");
590   else
591     Builder.defineMacro("__GNUC_STDC_INLINE__");
592 
593   if (LangOpts.NoInline)
594     Builder.defineMacro("__NO_INLINE__");
595 
596   if (unsigned PICLevel = LangOpts.PICLevel) {
597     Builder.defineMacro("__PIC__", Twine(PICLevel));
598     Builder.defineMacro("__pic__", Twine(PICLevel));
599   }
600 
601   // Macros to control C99 numerics and <float.h>
602   Builder.defineMacro("__FLT_EVAL_METHOD__", "0");
603   Builder.defineMacro("__FLT_RADIX__", "2");
604   int Dig = PickFP(&TI.getLongDoubleFormat(), -1/*FIXME*/, 17, 21, 33, 36);
605   Builder.defineMacro("__DECIMAL_DIG__", Twine(Dig));
606 
607   if (LangOpts.getStackProtector() == LangOptions::SSPOn)
608     Builder.defineMacro("__SSP__");
609   else if (LangOpts.getStackProtector() == LangOptions::SSPReq)
610     Builder.defineMacro("__SSP_ALL__", "2");
611 
612   if (FEOpts.ProgramAction == frontend::RewriteObjC)
613     Builder.defineMacro("__weak", "__attribute__((objc_gc(weak)))");
614 
615   // Define a macro that exists only when using the static analyzer.
616   if (FEOpts.ProgramAction == frontend::RunAnalysis)
617     Builder.defineMacro("__clang_analyzer__");
618 
619   if (LangOpts.FastRelaxedMath)
620     Builder.defineMacro("__FAST_RELAXED_MATH__");
621 
622   if (LangOpts.ObjCAutoRefCount) {
623     Builder.defineMacro("__weak", "__attribute__((objc_ownership(weak)))");
624     Builder.defineMacro("__strong", "__attribute__((objc_ownership(strong)))");
625     Builder.defineMacro("__autoreleasing",
626                         "__attribute__((objc_ownership(autoreleasing)))");
627     Builder.defineMacro("__unsafe_unretained",
628                         "__attribute__((objc_ownership(none)))");
629   }
630 
631   // Get other target #defines.
632   TI.getTargetDefines(LangOpts, Builder);
633 }
634 
635 // Initialize the remapping of files to alternative contents, e.g.,
636 // those specified through other files.
637 static void InitializeFileRemapping(Diagnostic &Diags,
638                                     SourceManager &SourceMgr,
639                                     FileManager &FileMgr,
640                                     const PreprocessorOptions &InitOpts) {
641   // Remap files in the source manager (with buffers).
642   for (PreprocessorOptions::const_remapped_file_buffer_iterator
643          Remap = InitOpts.remapped_file_buffer_begin(),
644          RemapEnd = InitOpts.remapped_file_buffer_end();
645        Remap != RemapEnd;
646        ++Remap) {
647     // Create the file entry for the file that we're mapping from.
648     const FileEntry *FromFile = FileMgr.getVirtualFile(Remap->first,
649                                                 Remap->second->getBufferSize(),
650                                                        0);
651     if (!FromFile) {
652       Diags.Report(diag::err_fe_remap_missing_from_file)
653         << Remap->first;
654       if (!InitOpts.RetainRemappedFileBuffers)
655         delete Remap->second;
656       continue;
657     }
658 
659     // Override the contents of the "from" file with the contents of
660     // the "to" file.
661     SourceMgr.overrideFileContents(FromFile, Remap->second,
662                                    InitOpts.RetainRemappedFileBuffers);
663   }
664 
665   // Remap files in the source manager (with other files).
666   for (PreprocessorOptions::const_remapped_file_iterator
667          Remap = InitOpts.remapped_file_begin(),
668          RemapEnd = InitOpts.remapped_file_end();
669        Remap != RemapEnd;
670        ++Remap) {
671     // Find the file that we're mapping to.
672     const FileEntry *ToFile = FileMgr.getFile(Remap->second);
673     if (!ToFile) {
674       Diags.Report(diag::err_fe_remap_missing_to_file)
675       << Remap->first << Remap->second;
676       continue;
677     }
678 
679     // Create the file entry for the file that we're mapping from.
680     const FileEntry *FromFile = FileMgr.getVirtualFile(Remap->first,
681                                                        ToFile->getSize(), 0);
682     if (!FromFile) {
683       Diags.Report(diag::err_fe_remap_missing_from_file)
684       << Remap->first;
685       continue;
686     }
687 
688     // Override the contents of the "from" file with the contents of
689     // the "to" file.
690     SourceMgr.overrideFileContents(FromFile, ToFile);
691   }
692 
693   SourceMgr.setOverridenFilesKeepOriginalName(
694                                         InitOpts.RemappedFilesKeepOriginalName);
695 }
696 
697 /// InitializePreprocessor - Initialize the preprocessor getting it and the
698 /// environment ready to process a single file. This returns true on error.
699 ///
700 void clang::InitializePreprocessor(Preprocessor &PP,
701                                    const PreprocessorOptions &InitOpts,
702                                    const HeaderSearchOptions &HSOpts,
703                                    const FrontendOptions &FEOpts) {
704   const LangOptions &LangOpts = PP.getLangOptions();
705   std::string PredefineBuffer;
706   PredefineBuffer.reserve(4080);
707   llvm::raw_string_ostream Predefines(PredefineBuffer);
708   MacroBuilder Builder(Predefines);
709 
710   InitializeFileRemapping(PP.getDiagnostics(), PP.getSourceManager(),
711                           PP.getFileManager(), InitOpts);
712 
713   // Specify whether the preprocessor should replace #include/#import with
714   // module imports when plausible.
715   PP.setAutoModuleImport(InitOpts.AutoModuleImport);
716 
717   // Emit line markers for various builtin sections of the file.  We don't do
718   // this in asm preprocessor mode, because "# 4" is not a line marker directive
719   // in this mode.
720   if (!PP.getLangOptions().AsmPreprocessor)
721     Builder.append("# 1 \"<built-in>\" 3");
722 
723   // Install things like __POWERPC__, __GNUC__, etc into the macro table.
724   if (InitOpts.UsePredefines) {
725     InitializePredefinedMacros(PP.getTargetInfo(), LangOpts, FEOpts, Builder);
726 
727     // Install definitions to make Objective-C++ ARC work well with various
728     // C++ Standard Library implementations.
729     if (LangOpts.ObjC1 && LangOpts.CPlusPlus && LangOpts.ObjCAutoRefCount) {
730       switch (InitOpts.ObjCXXARCStandardLibrary) {
731       case ARCXX_nolib:
732         break;
733 
734       case ARCXX_libcxx:
735         AddObjCXXARCLibcxxDefines(LangOpts, Builder);
736         break;
737 
738       case ARCXX_libstdcxx:
739         AddObjCXXARCLibstdcxxDefines(LangOpts, Builder);
740         break;
741       }
742     }
743   }
744 
745   // Even with predefines off, some macros are still predefined.
746   // These should all be defined in the preprocessor according to the
747   // current language configuration.
748   InitializeStandardPredefinedMacros(PP.getTargetInfo(), PP.getLangOptions(),
749                                      FEOpts, Builder);
750 
751   // Add on the predefines from the driver.  Wrap in a #line directive to report
752   // that they come from the command line.
753   if (!PP.getLangOptions().AsmPreprocessor)
754     Builder.append("# 1 \"<command line>\" 1");
755 
756   // Process #define's and #undef's in the order they are given.
757   for (unsigned i = 0, e = InitOpts.Macros.size(); i != e; ++i) {
758     if (InitOpts.Macros[i].second)  // isUndef
759       Builder.undefineMacro(InitOpts.Macros[i].first);
760     else
761       DefineBuiltinMacro(Builder, InitOpts.Macros[i].first,
762                          PP.getDiagnostics());
763   }
764 
765   // If -imacros are specified, include them now.  These are processed before
766   // any -include directives.
767   for (unsigned i = 0, e = InitOpts.MacroIncludes.size(); i != e; ++i)
768     AddImplicitIncludeMacros(Builder, InitOpts.MacroIncludes[i],
769                              PP.getFileManager());
770 
771   // Process -include directives.
772   for (unsigned i = 0, e = InitOpts.Includes.size(); i != e; ++i) {
773     const std::string &Path = InitOpts.Includes[i];
774     if (Path == InitOpts.ImplicitPTHInclude)
775       AddImplicitIncludePTH(Builder, PP, Path);
776     else
777       AddImplicitInclude(Builder, Path, PP.getFileManager());
778   }
779 
780   // Exit the command line and go back to <built-in> (2 is LC_LEAVE).
781   if (!PP.getLangOptions().AsmPreprocessor)
782     Builder.append("# 1 \"<built-in>\" 2");
783 
784   // Instruct the preprocessor to skip the preamble.
785   PP.setSkipMainFilePreamble(InitOpts.PrecompiledPreambleBytes.first,
786                              InitOpts.PrecompiledPreambleBytes.second);
787 
788   // Copy PredefinedBuffer into the Preprocessor.
789   PP.setPredefines(Predefines.str());
790 
791   // Initialize the header search object.
792   ApplyHeaderSearchOptions(PP.getHeaderSearchInfo(), HSOpts,
793                            PP.getLangOptions(),
794                            PP.getTargetInfo().getTriple());
795 }
796