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