xref: /llvm-project/clang/lib/Frontend/InitPreprocessor.cpp (revision c0cebeddb2014733a01d0af0624d489af8fa017b)
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/HeaderSearch.h"
22 #include "clang/Lex/Preprocessor.h"
23 #include "clang/Basic/FileManager.h"
24 #include "clang/Basic/SourceManager.h"
25 #include "llvm/ADT/APFloat.h"
26 #include "llvm/Support/FileSystem.h"
27 #include "llvm/Support/MemoryBuffer.h"
28 #include "llvm/Support/Path.h"
29 using namespace clang;
30 
31 // Append a #define line to Buf for Macro.  Macro should be of the form XXX,
32 // in which case we emit "#define XXX 1" or "XXX=Y z W" in which case we emit
33 // "#define XXX Y z W".  To get a #define with no value, use "XXX=".
34 static void DefineBuiltinMacro(MacroBuilder &Builder, StringRef Macro,
35                                DiagnosticsEngine &Diags) {
36   std::pair<StringRef, StringRef> MacroPair = Macro.split('=');
37   StringRef MacroName = MacroPair.first;
38   StringRef MacroBody = MacroPair.second;
39   if (MacroName.size() != Macro.size()) {
40     // Per GCC -D semantics, the macro ends at \n if it exists.
41     StringRef::size_type End = MacroBody.find_first_of("\n\r");
42     if (End != StringRef::npos)
43       Diags.Report(diag::warn_fe_macro_contains_embedded_newline)
44         << MacroName;
45     Builder.defineMacro(MacroName, MacroBody.substr(0, End));
46   } else {
47     // Push "macroname 1".
48     Builder.defineMacro(Macro);
49   }
50 }
51 
52 /// AddImplicitInclude - Add an implicit \#include of the specified file to the
53 /// predefines buffer.
54 static void AddImplicitInclude(MacroBuilder &Builder, StringRef File,
55                                FileManager &FileMgr) {
56   Builder.append(Twine("#include \"") +
57                  HeaderSearch::NormalizeDashIncludePath(File, FileMgr) + "\"");
58 }
59 
60 static void AddImplicitIncludeMacros(MacroBuilder &Builder,
61                                      StringRef File,
62                                      FileManager &FileMgr) {
63   Builder.append(Twine("#__include_macros \"") +
64                  HeaderSearch::NormalizeDashIncludePath(File, FileMgr) + "\"");
65   // Marker token to stop the __include_macros fetch loop.
66   Builder.append("##"); // ##?
67 }
68 
69 /// AddImplicitIncludePTH - Add an implicit \#include using the original file
70 /// used to generate a PTH cache.
71 static void AddImplicitIncludePTH(MacroBuilder &Builder, Preprocessor &PP,
72                                   StringRef ImplicitIncludePTH) {
73   PTHManager *P = PP.getPTHManager();
74   // Null check 'P' in the corner case where it couldn't be created.
75   const char *OriginalFile = P ? P->getOriginalSourceFile() : 0;
76 
77   if (!OriginalFile) {
78     PP.getDiagnostics().Report(diag::err_fe_pth_file_has_no_source_header)
79       << ImplicitIncludePTH;
80     return;
81   }
82 
83   AddImplicitInclude(Builder, OriginalFile, PP.getFileManager());
84 }
85 
86 /// PickFP - This is used to pick a value based on the FP semantics of the
87 /// specified FP model.
88 template <typename T>
89 static T PickFP(const llvm::fltSemantics *Sem, T IEEESingleVal,
90                 T IEEEDoubleVal, T X87DoubleExtendedVal, T PPCDoubleDoubleVal,
91                 T IEEEQuadVal) {
92   if (Sem == (const llvm::fltSemantics*)&llvm::APFloat::IEEEsingle)
93     return IEEESingleVal;
94   if (Sem == (const llvm::fltSemantics*)&llvm::APFloat::IEEEdouble)
95     return IEEEDoubleVal;
96   if (Sem == (const llvm::fltSemantics*)&llvm::APFloat::x87DoubleExtended)
97     return X87DoubleExtendedVal;
98   if (Sem == (const llvm::fltSemantics*)&llvm::APFloat::PPCDoubleDouble)
99     return PPCDoubleDoubleVal;
100   assert(Sem == (const llvm::fltSemantics*)&llvm::APFloat::IEEEquad);
101   return IEEEQuadVal;
102 }
103 
104 static void DefineFloatMacros(MacroBuilder &Builder, StringRef Prefix,
105                               const llvm::fltSemantics *Sem) {
106   const char *DenormMin, *Epsilon, *Max, *Min;
107   DenormMin = PickFP(Sem, "1.40129846e-45F", "4.9406564584124654e-324",
108                      "3.64519953188247460253e-4951L",
109                      "4.94065645841246544176568792868221e-324L",
110                      "6.47517511943802511092443895822764655e-4966L");
111   int Digits = PickFP(Sem, 6, 15, 18, 31, 33);
112   Epsilon = PickFP(Sem, "1.19209290e-7F", "2.2204460492503131e-16",
113                    "1.08420217248550443401e-19L",
114                    "4.94065645841246544176568792868221e-324L",
115                    "1.92592994438723585305597794258492732e-34L");
116   int MantissaDigits = PickFP(Sem, 24, 53, 64, 106, 113);
117   int Min10Exp = PickFP(Sem, -37, -307, -4931, -291, -4931);
118   int Max10Exp = PickFP(Sem, 38, 308, 4932, 308, 4932);
119   int MinExp = PickFP(Sem, -125, -1021, -16381, -968, -16381);
120   int MaxExp = PickFP(Sem, 128, 1024, 16384, 1024, 16384);
121   Min = PickFP(Sem, "1.17549435e-38F", "2.2250738585072014e-308",
122                "3.36210314311209350626e-4932L",
123                "2.00416836000897277799610805135016e-292L",
124                "3.36210314311209350626267781732175260e-4932L");
125   Max = PickFP(Sem, "3.40282347e+38F", "1.7976931348623157e+308",
126                "1.18973149535723176502e+4932L",
127                "1.79769313486231580793728971405301e+308L",
128                "1.18973149535723176508575932662800702e+4932L");
129 
130   SmallString<32> DefPrefix;
131   DefPrefix = "__";
132   DefPrefix += Prefix;
133   DefPrefix += "_";
134 
135   Builder.defineMacro(DefPrefix + "DENORM_MIN__", DenormMin);
136   Builder.defineMacro(DefPrefix + "HAS_DENORM__");
137   Builder.defineMacro(DefPrefix + "DIG__", Twine(Digits));
138   Builder.defineMacro(DefPrefix + "EPSILON__", Twine(Epsilon));
139   Builder.defineMacro(DefPrefix + "HAS_INFINITY__");
140   Builder.defineMacro(DefPrefix + "HAS_QUIET_NAN__");
141   Builder.defineMacro(DefPrefix + "MANT_DIG__", Twine(MantissaDigits));
142 
143   Builder.defineMacro(DefPrefix + "MAX_10_EXP__", Twine(Max10Exp));
144   Builder.defineMacro(DefPrefix + "MAX_EXP__", Twine(MaxExp));
145   Builder.defineMacro(DefPrefix + "MAX__", Twine(Max));
146 
147   Builder.defineMacro(DefPrefix + "MIN_10_EXP__","("+Twine(Min10Exp)+")");
148   Builder.defineMacro(DefPrefix + "MIN_EXP__", "("+Twine(MinExp)+")");
149   Builder.defineMacro(DefPrefix + "MIN__", Twine(Min));
150 }
151 
152 
153 /// DefineTypeSize - Emit a macro to the predefines buffer that declares a macro
154 /// named MacroName with the max value for a type with width 'TypeWidth' a
155 /// signedness of 'isSigned' and with a value suffix of 'ValSuffix' (e.g. LL).
156 static void DefineTypeSize(StringRef MacroName, unsigned TypeWidth,
157                            StringRef ValSuffix, bool isSigned,
158                            MacroBuilder &Builder) {
159   llvm::APInt MaxVal = isSigned ? llvm::APInt::getSignedMaxValue(TypeWidth)
160                                 : llvm::APInt::getMaxValue(TypeWidth);
161   Builder.defineMacro(MacroName, MaxVal.toString(10, isSigned) + ValSuffix);
162 }
163 
164 /// DefineTypeSize - An overloaded helper that uses TargetInfo to determine
165 /// the width, suffix, and signedness of the given type
166 static void DefineTypeSize(StringRef MacroName, TargetInfo::IntType Ty,
167                            const TargetInfo &TI, MacroBuilder &Builder) {
168   DefineTypeSize(MacroName, TI.getTypeWidth(Ty), TI.getTypeConstantSuffix(Ty),
169                  TI.isTypeSigned(Ty), Builder);
170 }
171 
172 static void DefineType(const Twine &MacroName, TargetInfo::IntType Ty,
173                        MacroBuilder &Builder) {
174   Builder.defineMacro(MacroName, TargetInfo::getTypeName(Ty));
175 }
176 
177 static void DefineTypeWidth(StringRef MacroName, TargetInfo::IntType Ty,
178                             const TargetInfo &TI, MacroBuilder &Builder) {
179   Builder.defineMacro(MacroName, Twine(TI.getTypeWidth(Ty)));
180 }
181 
182 static void DefineTypeSizeof(StringRef MacroName, unsigned BitWidth,
183                              const TargetInfo &TI, MacroBuilder &Builder) {
184   Builder.defineMacro(MacroName,
185                       Twine(BitWidth / TI.getCharWidth()));
186 }
187 
188 static void DefineExactWidthIntType(TargetInfo::IntType Ty,
189                                const TargetInfo &TI, MacroBuilder &Builder) {
190   int TypeWidth = TI.getTypeWidth(Ty);
191 
192   // Use the target specified int64 type, when appropriate, so that [u]int64_t
193   // ends up being defined in terms of the correct type.
194   if (TypeWidth == 64)
195     Ty = TI.getInt64Type();
196 
197   DefineType("__INT" + Twine(TypeWidth) + "_TYPE__", Ty, Builder);
198 
199   StringRef ConstSuffix(TargetInfo::getTypeConstantSuffix(Ty));
200   if (!ConstSuffix.empty())
201     Builder.defineMacro("__INT" + Twine(TypeWidth) + "_C_SUFFIX__",
202                         ConstSuffix);
203 }
204 
205 /// Get the value the ATOMIC_*_LOCK_FREE macro should have for a type with
206 /// the specified properties.
207 static const char *getLockFreeValue(unsigned TypeWidth, unsigned TypeAlign,
208                                     unsigned InlineWidth) {
209   // Fully-aligned, power-of-2 sizes no larger than the inline
210   // width will be inlined as lock-free operations.
211   if (TypeWidth == TypeAlign && (TypeWidth & (TypeWidth - 1)) == 0 &&
212       TypeWidth <= InlineWidth)
213     return "2"; // "always lock free"
214   // We cannot be certain what operations the lib calls might be
215   // able to implement as lock-free on future processors.
216   return "1"; // "sometimes lock free"
217 }
218 
219 /// \brief Add definitions required for a smooth interaction between
220 /// Objective-C++ automated reference counting and libstdc++ (4.2).
221 static void AddObjCXXARCLibstdcxxDefines(const LangOptions &LangOpts,
222                                          MacroBuilder &Builder) {
223   Builder.defineMacro("_GLIBCXX_PREDEFINED_OBJC_ARC_IS_SCALAR");
224 
225   std::string Result;
226   {
227     // Provide specializations for the __is_scalar type trait so that
228     // lifetime-qualified objects are not considered "scalar" types, which
229     // libstdc++ uses as an indicator of the presence of trivial copy, assign,
230     // default-construct, and destruct semantics (none of which hold for
231     // lifetime-qualified objects in ARC).
232     llvm::raw_string_ostream Out(Result);
233 
234     Out << "namespace std {\n"
235         << "\n"
236         << "struct __true_type;\n"
237         << "struct __false_type;\n"
238         << "\n";
239 
240     Out << "template<typename _Tp> struct __is_scalar;\n"
241         << "\n";
242 
243     Out << "template<typename _Tp>\n"
244         << "struct __is_scalar<__attribute__((objc_ownership(strong))) _Tp> {\n"
245         << "  enum { __value = 0 };\n"
246         << "  typedef __false_type __type;\n"
247         << "};\n"
248         << "\n";
249 
250     if (LangOpts.ObjCRuntimeHasWeak) {
251       Out << "template<typename _Tp>\n"
252           << "struct __is_scalar<__attribute__((objc_ownership(weak))) _Tp> {\n"
253           << "  enum { __value = 0 };\n"
254           << "  typedef __false_type __type;\n"
255           << "};\n"
256           << "\n";
257     }
258 
259     Out << "template<typename _Tp>\n"
260         << "struct __is_scalar<__attribute__((objc_ownership(autoreleasing)))"
261         << " _Tp> {\n"
262         << "  enum { __value = 0 };\n"
263         << "  typedef __false_type __type;\n"
264         << "};\n"
265         << "\n";
266 
267     Out << "}\n";
268   }
269   Builder.append(Result);
270 }
271 
272 static void InitializeStandardPredefinedMacros(const TargetInfo &TI,
273                                                const LangOptions &LangOpts,
274                                                const FrontendOptions &FEOpts,
275                                                MacroBuilder &Builder) {
276   if (!LangOpts.MicrosoftMode && !LangOpts.TraditionalCPP)
277     Builder.defineMacro("__STDC__");
278   if (LangOpts.Freestanding)
279     Builder.defineMacro("__STDC_HOSTED__", "0");
280   else
281     Builder.defineMacro("__STDC_HOSTED__");
282 
283   if (!LangOpts.CPlusPlus) {
284     if (LangOpts.C11)
285       Builder.defineMacro("__STDC_VERSION__", "201112L");
286     else if (LangOpts.C99)
287       Builder.defineMacro("__STDC_VERSION__", "199901L");
288     else if (!LangOpts.GNUMode && LangOpts.Digraphs)
289       Builder.defineMacro("__STDC_VERSION__", "199409L");
290   } else {
291     // C++11 [cpp.predefined]p1:
292     //   The name __cplusplus is defined to the value 201103L when compiling a
293     //   C++ translation unit.
294     if (LangOpts.CPlusPlus0x)
295       Builder.defineMacro("__cplusplus", "201103L");
296     // C++03 [cpp.predefined]p1:
297     //   The name __cplusplus is defined to the value 199711L when compiling a
298     //   C++ translation unit.
299     else
300       Builder.defineMacro("__cplusplus", "199711L");
301   }
302 
303   if (LangOpts.ObjC1)
304     Builder.defineMacro("__OBJC__");
305 
306   // Not "standard" per se, but available even with the -undef flag.
307   if (LangOpts.AsmPreprocessor)
308     Builder.defineMacro("__ASSEMBLER__");
309 }
310 
311 static void InitializePredefinedMacros(const TargetInfo &TI,
312                                        const LangOptions &LangOpts,
313                                        const FrontendOptions &FEOpts,
314                                        MacroBuilder &Builder) {
315   // Compiler version introspection macros.
316   Builder.defineMacro("__llvm__");  // LLVM Backend
317   Builder.defineMacro("__clang__"); // Clang Frontend
318 #define TOSTR2(X) #X
319 #define TOSTR(X) TOSTR2(X)
320   Builder.defineMacro("__clang_major__", TOSTR(CLANG_VERSION_MAJOR));
321   Builder.defineMacro("__clang_minor__", TOSTR(CLANG_VERSION_MINOR));
322 #ifdef CLANG_VERSION_PATCHLEVEL
323   Builder.defineMacro("__clang_patchlevel__", TOSTR(CLANG_VERSION_PATCHLEVEL));
324 #else
325   Builder.defineMacro("__clang_patchlevel__", "0");
326 #endif
327   Builder.defineMacro("__clang_version__",
328                       "\"" CLANG_VERSION_STRING " ("
329                       + getClangFullRepositoryVersion() + ")\"");
330 #undef TOSTR
331 #undef TOSTR2
332   if (!LangOpts.MicrosoftMode) {
333     // Currently claim to be compatible with GCC 4.2.1-5621, but only if we're
334     // not compiling for MSVC compatibility
335     Builder.defineMacro("__GNUC_MINOR__", "2");
336     Builder.defineMacro("__GNUC_PATCHLEVEL__", "1");
337     Builder.defineMacro("__GNUC__", "4");
338     Builder.defineMacro("__GXX_ABI_VERSION", "1002");
339   }
340 
341   // Define macros for the C11 / C++11 memory orderings
342   Builder.defineMacro("__ATOMIC_RELAXED", "0");
343   Builder.defineMacro("__ATOMIC_CONSUME", "1");
344   Builder.defineMacro("__ATOMIC_ACQUIRE", "2");
345   Builder.defineMacro("__ATOMIC_RELEASE", "3");
346   Builder.defineMacro("__ATOMIC_ACQ_REL", "4");
347   Builder.defineMacro("__ATOMIC_SEQ_CST", "5");
348 
349   // Support for #pragma redefine_extname (Sun compatibility)
350   Builder.defineMacro("__PRAGMA_REDEFINE_EXTNAME", "1");
351 
352   // As sad as it is, enough software depends on the __VERSION__ for version
353   // checks that it is necessary to report 4.2.1 (the base GCC version we claim
354   // compatibility with) first.
355   Builder.defineMacro("__VERSION__", "\"4.2.1 Compatible " +
356                       Twine(getClangFullCPPVersion()) + "\"");
357 
358   // Initialize language-specific preprocessor defines.
359 
360   // Standard conforming mode?
361   if (!LangOpts.GNUMode)
362     Builder.defineMacro("__STRICT_ANSI__");
363 
364   if (LangOpts.CPlusPlus0x)
365     Builder.defineMacro("__GXX_EXPERIMENTAL_CXX0X__");
366 
367   if (LangOpts.ObjC1) {
368     if (LangOpts.ObjCRuntime.isNonFragile()) {
369       Builder.defineMacro("__OBJC2__");
370 
371       if (LangOpts.ObjCExceptions)
372         Builder.defineMacro("OBJC_ZEROCOST_EXCEPTIONS");
373     }
374 
375     if (LangOpts.getGC() != LangOptions::NonGC)
376       Builder.defineMacro("__OBJC_GC__");
377 
378     if (LangOpts.ObjCRuntime.isNeXTFamily())
379       Builder.defineMacro("__NEXT_RUNTIME__");
380 
381     Builder.defineMacro("IBOutlet", "__attribute__((iboutlet))");
382     Builder.defineMacro("IBOutletCollection(ClassName)",
383                         "__attribute__((iboutletcollection(ClassName)))");
384     Builder.defineMacro("IBAction", "void)__attribute__((ibaction)");
385   }
386 
387   // darwin_constant_cfstrings controls this. This is also dependent
388   // on other things like the runtime I believe.  This is set even for C code.
389   if (!LangOpts.NoConstantCFStrings)
390       Builder.defineMacro("__CONSTANT_CFSTRINGS__");
391 
392   if (LangOpts.ObjC2)
393     Builder.defineMacro("OBJC_NEW_PROPERTIES");
394 
395   if (LangOpts.PascalStrings)
396     Builder.defineMacro("__PASCAL_STRINGS__");
397 
398   if (LangOpts.Blocks) {
399     Builder.defineMacro("__block", "__attribute__((__blocks__(byref)))");
400     Builder.defineMacro("__BLOCKS__");
401   }
402 
403   if (LangOpts.CXXExceptions)
404     Builder.defineMacro("__EXCEPTIONS");
405   if (LangOpts.RTTI)
406     Builder.defineMacro("__GXX_RTTI");
407   if (LangOpts.SjLjExceptions)
408     Builder.defineMacro("__USING_SJLJ_EXCEPTIONS__");
409 
410   if (LangOpts.Deprecated)
411     Builder.defineMacro("__DEPRECATED");
412 
413   if (LangOpts.CPlusPlus) {
414     Builder.defineMacro("__GNUG__", "4");
415     Builder.defineMacro("__GXX_WEAK__");
416     Builder.defineMacro("__private_extern__", "extern");
417   }
418 
419   if (LangOpts.MicrosoftExt) {
420     // Both __PRETTY_FUNCTION__ and __FUNCTION__ are GCC extensions, however
421     // VC++ appears to only like __FUNCTION__.
422     Builder.defineMacro("__PRETTY_FUNCTION__", "__FUNCTION__");
423     // Work around some issues with Visual C++ headerws.
424     if (LangOpts.CPlusPlus) {
425       // Since we define wchar_t in C++ mode.
426       Builder.defineMacro("_WCHAR_T_DEFINED");
427       Builder.defineMacro("_NATIVE_WCHAR_T_DEFINED");
428       // FIXME: Support Microsoft's __identifier extension in the lexer.
429       Builder.append("#define __identifier(x) x");
430       Builder.append("class type_info;");
431     }
432 
433     if (LangOpts.CPlusPlus0x) {
434       Builder.defineMacro("_HAS_CHAR16_T_LANGUAGE_SUPPORT", "1");
435     }
436   }
437 
438   if (LangOpts.Optimize)
439     Builder.defineMacro("__OPTIMIZE__");
440   if (LangOpts.OptimizeSize)
441     Builder.defineMacro("__OPTIMIZE_SIZE__");
442 
443   if (LangOpts.FastMath)
444     Builder.defineMacro("__FAST_MATH__");
445 
446   // Initialize target-specific preprocessor defines.
447 
448   // __BYTE_ORDER__ was added in GCC 4.6. It's analogous
449   // to the macro __BYTE_ORDER (no trailing underscores)
450   // from glibc's <endian.h> header.
451   // We don't support the PDP-11 as a target, but include
452   // the define so it can still be compared against.
453   Builder.defineMacro("__ORDER_LITTLE_ENDIAN__", "1234");
454   Builder.defineMacro("__ORDER_BIG_ENDIAN__",    "4321");
455   Builder.defineMacro("__ORDER_PDP_ENDIAN__",    "3412");
456   if (TI.isBigEndian())
457     Builder.defineMacro("__BYTE_ORDER__", "__ORDER_BIG_ENDIAN__");
458   else
459     Builder.defineMacro("__BYTE_ORDER__", "__ORDER_LITTLE_ENDIAN__");
460 
461   // Define type sizing macros based on the target properties.
462   assert(TI.getCharWidth() == 8 && "Only support 8-bit char so far");
463   Builder.defineMacro("__CHAR_BIT__", "8");
464 
465   DefineTypeSize("__SCHAR_MAX__", TI.getCharWidth(), "", true, Builder);
466   DefineTypeSize("__SHRT_MAX__", TargetInfo::SignedShort, TI, Builder);
467   DefineTypeSize("__INT_MAX__", TargetInfo::SignedInt, TI, Builder);
468   DefineTypeSize("__LONG_MAX__", TargetInfo::SignedLong, TI, Builder);
469   DefineTypeSize("__LONG_LONG_MAX__", TargetInfo::SignedLongLong, TI, Builder);
470   DefineTypeSize("__WCHAR_MAX__", TI.getWCharType(), TI, Builder);
471   DefineTypeSize("__INTMAX_MAX__", TI.getIntMaxType(), TI, Builder);
472 
473   DefineTypeSizeof("__SIZEOF_DOUBLE__", TI.getDoubleWidth(), TI, Builder);
474   DefineTypeSizeof("__SIZEOF_FLOAT__", TI.getFloatWidth(), TI, Builder);
475   DefineTypeSizeof("__SIZEOF_INT__", TI.getIntWidth(), TI, Builder);
476   DefineTypeSizeof("__SIZEOF_LONG__", TI.getLongWidth(), TI, Builder);
477   DefineTypeSizeof("__SIZEOF_LONG_DOUBLE__",TI.getLongDoubleWidth(),TI,Builder);
478   DefineTypeSizeof("__SIZEOF_LONG_LONG__", TI.getLongLongWidth(), TI, Builder);
479   DefineTypeSizeof("__SIZEOF_POINTER__", TI.getPointerWidth(0), TI, Builder);
480   DefineTypeSizeof("__SIZEOF_SHORT__", TI.getShortWidth(), TI, Builder);
481   DefineTypeSizeof("__SIZEOF_PTRDIFF_T__",
482                    TI.getTypeWidth(TI.getPtrDiffType(0)), TI, Builder);
483   DefineTypeSizeof("__SIZEOF_SIZE_T__",
484                    TI.getTypeWidth(TI.getSizeType()), TI, Builder);
485   DefineTypeSizeof("__SIZEOF_WCHAR_T__",
486                    TI.getTypeWidth(TI.getWCharType()), TI, Builder);
487   DefineTypeSizeof("__SIZEOF_WINT_T__",
488                    TI.getTypeWidth(TI.getWIntType()), TI, Builder);
489 
490   DefineType("__INTMAX_TYPE__", TI.getIntMaxType(), Builder);
491   DefineType("__UINTMAX_TYPE__", TI.getUIntMaxType(), Builder);
492   DefineTypeWidth("__INTMAX_WIDTH__",  TI.getIntMaxType(), TI, Builder);
493   DefineType("__PTRDIFF_TYPE__", TI.getPtrDiffType(0), Builder);
494   DefineTypeWidth("__PTRDIFF_WIDTH__", TI.getPtrDiffType(0), TI, Builder);
495   DefineType("__INTPTR_TYPE__", TI.getIntPtrType(), Builder);
496   DefineTypeWidth("__INTPTR_WIDTH__", TI.getIntPtrType(), TI, Builder);
497   DefineType("__SIZE_TYPE__", TI.getSizeType(), Builder);
498   DefineTypeWidth("__SIZE_WIDTH__", TI.getSizeType(), TI, Builder);
499   DefineType("__WCHAR_TYPE__", TI.getWCharType(), Builder);
500   DefineTypeWidth("__WCHAR_WIDTH__", TI.getWCharType(), TI, Builder);
501   DefineType("__WINT_TYPE__", TI.getWIntType(), Builder);
502   DefineTypeWidth("__WINT_WIDTH__", TI.getWIntType(), TI, Builder);
503   DefineTypeWidth("__SIG_ATOMIC_WIDTH__", TI.getSigAtomicType(), TI, Builder);
504   DefineType("__CHAR16_TYPE__", TI.getChar16Type(), Builder);
505   DefineType("__CHAR32_TYPE__", TI.getChar32Type(), Builder);
506 
507   DefineFloatMacros(Builder, "FLT", &TI.getFloatFormat());
508   DefineFloatMacros(Builder, "DBL", &TI.getDoubleFormat());
509   DefineFloatMacros(Builder, "LDBL", &TI.getLongDoubleFormat());
510 
511   // Define a __POINTER_WIDTH__ macro for stdint.h.
512   Builder.defineMacro("__POINTER_WIDTH__",
513                       Twine((int)TI.getPointerWidth(0)));
514 
515   if (!LangOpts.CharIsSigned)
516     Builder.defineMacro("__CHAR_UNSIGNED__");
517 
518   if (!TargetInfo::isTypeSigned(TI.getWCharType()))
519     Builder.defineMacro("__WCHAR_UNSIGNED__");
520 
521   if (!TargetInfo::isTypeSigned(TI.getWIntType()))
522     Builder.defineMacro("__WINT_UNSIGNED__");
523 
524   // Define exact-width integer types for stdint.h
525   Builder.defineMacro("__INT" + Twine(TI.getCharWidth()) + "_TYPE__",
526                       "char");
527 
528   if (TI.getShortWidth() > TI.getCharWidth())
529     DefineExactWidthIntType(TargetInfo::SignedShort, TI, Builder);
530 
531   if (TI.getIntWidth() > TI.getShortWidth())
532     DefineExactWidthIntType(TargetInfo::SignedInt, TI, Builder);
533 
534   if (TI.getLongWidth() > TI.getIntWidth())
535     DefineExactWidthIntType(TargetInfo::SignedLong, TI, Builder);
536 
537   if (TI.getLongLongWidth() > TI.getLongWidth())
538     DefineExactWidthIntType(TargetInfo::SignedLongLong, TI, Builder);
539 
540   if (const char *Prefix = TI.getUserLabelPrefix())
541     Builder.defineMacro("__USER_LABEL_PREFIX__", Prefix);
542 
543   if (LangOpts.FastMath || LangOpts.FiniteMathOnly)
544     Builder.defineMacro("__FINITE_MATH_ONLY__", "1");
545   else
546     Builder.defineMacro("__FINITE_MATH_ONLY__", "0");
547 
548   if (LangOpts.GNUInline)
549     Builder.defineMacro("__GNUC_GNU_INLINE__");
550   else
551     Builder.defineMacro("__GNUC_STDC_INLINE__");
552 
553   // The value written by __atomic_test_and_set.
554   // FIXME: This is target-dependent.
555   Builder.defineMacro("__GCC_ATOMIC_TEST_AND_SET_TRUEVAL", "1");
556 
557   // Used by libstdc++ to implement ATOMIC_<foo>_LOCK_FREE.
558   unsigned InlineWidthBits = TI.getMaxAtomicInlineWidth();
559 #define DEFINE_LOCK_FREE_MACRO(TYPE, Type) \
560   Builder.defineMacro("__GCC_ATOMIC_" #TYPE "_LOCK_FREE", \
561                       getLockFreeValue(TI.get##Type##Width(), \
562                                        TI.get##Type##Align(), \
563                                        InlineWidthBits));
564   DEFINE_LOCK_FREE_MACRO(BOOL, Bool);
565   DEFINE_LOCK_FREE_MACRO(CHAR, Char);
566   DEFINE_LOCK_FREE_MACRO(CHAR16_T, Char16);
567   DEFINE_LOCK_FREE_MACRO(CHAR32_T, Char32);
568   DEFINE_LOCK_FREE_MACRO(WCHAR_T, WChar);
569   DEFINE_LOCK_FREE_MACRO(SHORT, Short);
570   DEFINE_LOCK_FREE_MACRO(INT, Int);
571   DEFINE_LOCK_FREE_MACRO(LONG, Long);
572   DEFINE_LOCK_FREE_MACRO(LLONG, LongLong);
573   Builder.defineMacro("__GCC_ATOMIC_POINTER_LOCK_FREE",
574                       getLockFreeValue(TI.getPointerWidth(0),
575                                        TI.getPointerAlign(0),
576                                        InlineWidthBits));
577 #undef DEFINE_LOCK_FREE_MACRO
578 
579   if (LangOpts.NoInlineDefine)
580     Builder.defineMacro("__NO_INLINE__");
581 
582   if (unsigned PICLevel = LangOpts.PICLevel) {
583     Builder.defineMacro("__PIC__", Twine(PICLevel));
584     Builder.defineMacro("__pic__", Twine(PICLevel));
585   }
586   if (unsigned PIELevel = LangOpts.PIELevel) {
587     Builder.defineMacro("__PIE__", Twine(PIELevel));
588     Builder.defineMacro("__pie__", Twine(PIELevel));
589   }
590 
591   // Macros to control C99 numerics and <float.h>
592   Builder.defineMacro("__FLT_EVAL_METHOD__", Twine(TI.getFloatEvalMethod()));
593   Builder.defineMacro("__FLT_RADIX__", "2");
594   int Dig = PickFP(&TI.getLongDoubleFormat(), -1/*FIXME*/, 17, 21, 33, 36);
595   Builder.defineMacro("__DECIMAL_DIG__", Twine(Dig));
596 
597   if (LangOpts.getStackProtector() == LangOptions::SSPOn)
598     Builder.defineMacro("__SSP__");
599   else if (LangOpts.getStackProtector() == LangOptions::SSPReq)
600     Builder.defineMacro("__SSP_ALL__", "2");
601 
602   if (FEOpts.ProgramAction == frontend::RewriteObjC)
603     Builder.defineMacro("__weak", "__attribute__((objc_gc(weak)))");
604 
605   // Define a macro that exists only when using the static analyzer.
606   if (FEOpts.ProgramAction == frontend::RunAnalysis)
607     Builder.defineMacro("__clang_analyzer__");
608 
609   if (LangOpts.FastRelaxedMath)
610     Builder.defineMacro("__FAST_RELAXED_MATH__");
611 
612   if (LangOpts.ObjCAutoRefCount) {
613     Builder.defineMacro("__weak", "__attribute__((objc_ownership(weak)))");
614     Builder.defineMacro("__strong", "__attribute__((objc_ownership(strong)))");
615     Builder.defineMacro("__autoreleasing",
616                         "__attribute__((objc_ownership(autoreleasing)))");
617     Builder.defineMacro("__unsafe_unretained",
618                         "__attribute__((objc_ownership(none)))");
619   }
620 
621   // Get other target #defines.
622   TI.getTargetDefines(LangOpts, Builder);
623 }
624 
625 // Initialize the remapping of files to alternative contents, e.g.,
626 // those specified through other files.
627 static void InitializeFileRemapping(DiagnosticsEngine &Diags,
628                                     SourceManager &SourceMgr,
629                                     FileManager &FileMgr,
630                                     const PreprocessorOptions &InitOpts) {
631   // Remap files in the source manager (with buffers).
632   for (PreprocessorOptions::const_remapped_file_buffer_iterator
633          Remap = InitOpts.remapped_file_buffer_begin(),
634          RemapEnd = InitOpts.remapped_file_buffer_end();
635        Remap != RemapEnd;
636        ++Remap) {
637     // Create the file entry for the file that we're mapping from.
638     const FileEntry *FromFile = FileMgr.getVirtualFile(Remap->first,
639                                                 Remap->second->getBufferSize(),
640                                                        0);
641     if (!FromFile) {
642       Diags.Report(diag::err_fe_remap_missing_from_file)
643         << Remap->first;
644       if (!InitOpts.RetainRemappedFileBuffers)
645         delete Remap->second;
646       continue;
647     }
648 
649     // Override the contents of the "from" file with the contents of
650     // the "to" file.
651     SourceMgr.overrideFileContents(FromFile, Remap->second,
652                                    InitOpts.RetainRemappedFileBuffers);
653   }
654 
655   // Remap files in the source manager (with other files).
656   for (PreprocessorOptions::const_remapped_file_iterator
657          Remap = InitOpts.remapped_file_begin(),
658          RemapEnd = InitOpts.remapped_file_end();
659        Remap != RemapEnd;
660        ++Remap) {
661     // Find the file that we're mapping to.
662     const FileEntry *ToFile = FileMgr.getFile(Remap->second);
663     if (!ToFile) {
664       Diags.Report(diag::err_fe_remap_missing_to_file)
665       << Remap->first << Remap->second;
666       continue;
667     }
668 
669     // Create the file entry for the file that we're mapping from.
670     const FileEntry *FromFile = FileMgr.getVirtualFile(Remap->first,
671                                                        ToFile->getSize(), 0);
672     if (!FromFile) {
673       Diags.Report(diag::err_fe_remap_missing_from_file)
674       << Remap->first;
675       continue;
676     }
677 
678     // Override the contents of the "from" file with the contents of
679     // the "to" file.
680     SourceMgr.overrideFileContents(FromFile, ToFile);
681   }
682 
683   SourceMgr.setOverridenFilesKeepOriginalName(
684                                         InitOpts.RemappedFilesKeepOriginalName);
685 }
686 
687 /// InitializePreprocessor - Initialize the preprocessor getting it and the
688 /// environment ready to process a single file. This returns true on error.
689 ///
690 void clang::InitializePreprocessor(Preprocessor &PP,
691                                    const PreprocessorOptions &InitOpts,
692                                    const HeaderSearchOptions &HSOpts,
693                                    const FrontendOptions &FEOpts) {
694   const LangOptions &LangOpts = PP.getLangOpts();
695   std::string PredefineBuffer;
696   PredefineBuffer.reserve(4080);
697   llvm::raw_string_ostream Predefines(PredefineBuffer);
698   MacroBuilder Builder(Predefines);
699 
700   InitializeFileRemapping(PP.getDiagnostics(), PP.getSourceManager(),
701                           PP.getFileManager(), InitOpts);
702 
703   // Emit line markers for various builtin sections of the file.  We don't do
704   // this in asm preprocessor mode, because "# 4" is not a line marker directive
705   // in this mode.
706   if (!PP.getLangOpts().AsmPreprocessor)
707     Builder.append("# 1 \"<built-in>\" 3");
708 
709   // Install things like __POWERPC__, __GNUC__, etc into the macro table.
710   if (InitOpts.UsePredefines) {
711     InitializePredefinedMacros(PP.getTargetInfo(), LangOpts, FEOpts, Builder);
712 
713     // Install definitions to make Objective-C++ ARC work well with various
714     // C++ Standard Library implementations.
715     if (LangOpts.ObjC1 && LangOpts.CPlusPlus && LangOpts.ObjCAutoRefCount) {
716       switch (InitOpts.ObjCXXARCStandardLibrary) {
717       case ARCXX_nolib:
718         case ARCXX_libcxx:
719         break;
720 
721       case ARCXX_libstdcxx:
722         AddObjCXXARCLibstdcxxDefines(LangOpts, Builder);
723         break;
724       }
725     }
726   }
727 
728   // Even with predefines off, some macros are still predefined.
729   // These should all be defined in the preprocessor according to the
730   // current language configuration.
731   InitializeStandardPredefinedMacros(PP.getTargetInfo(), PP.getLangOpts(),
732                                      FEOpts, Builder);
733 
734   // Add on the predefines from the driver.  Wrap in a #line directive to report
735   // that they come from the command line.
736   if (!PP.getLangOpts().AsmPreprocessor)
737     Builder.append("# 1 \"<command line>\" 1");
738 
739   // Process #define's and #undef's in the order they are given.
740   for (unsigned i = 0, e = InitOpts.Macros.size(); i != e; ++i) {
741     if (InitOpts.Macros[i].second)  // isUndef
742       Builder.undefineMacro(InitOpts.Macros[i].first);
743     else
744       DefineBuiltinMacro(Builder, InitOpts.Macros[i].first,
745                          PP.getDiagnostics());
746   }
747 
748   // If -imacros are specified, include them now.  These are processed before
749   // any -include directives.
750   for (unsigned i = 0, e = InitOpts.MacroIncludes.size(); i != e; ++i)
751     AddImplicitIncludeMacros(Builder, InitOpts.MacroIncludes[i],
752                              PP.getFileManager());
753 
754   // Process -include directives.
755   for (unsigned i = 0, e = InitOpts.Includes.size(); i != e; ++i) {
756     const std::string &Path = InitOpts.Includes[i];
757     if (Path == InitOpts.ImplicitPTHInclude)
758       AddImplicitIncludePTH(Builder, PP, Path);
759     else
760       AddImplicitInclude(Builder, Path, PP.getFileManager());
761   }
762 
763   // Exit the command line and go back to <built-in> (2 is LC_LEAVE).
764   if (!PP.getLangOpts().AsmPreprocessor)
765     Builder.append("# 1 \"<built-in>\" 2");
766 
767   // Instruct the preprocessor to skip the preamble.
768   PP.setSkipMainFilePreamble(InitOpts.PrecompiledPreambleBytes.first,
769                              InitOpts.PrecompiledPreambleBytes.second);
770 
771   // Copy PredefinedBuffer into the Preprocessor.
772   PP.setPredefines(Predefines.str());
773 
774   // Initialize the header search object.
775   ApplyHeaderSearchOptions(PP.getHeaderSearchInfo(), HSOpts,
776                            PP.getLangOpts(),
777                            PP.getTargetInfo().getTriple());
778 }
779