xref: /llvm-project/clang/lib/Frontend/InitPreprocessor.cpp (revision 2c4542d3ec48fbb449b6633eef837bf0d3c901db)
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.MicrosoftMode && !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     // FIXME: C1x doesn't have a defined version number yet, so pick something
290     // that is the minimum possible according to their placeholder scheme
291     // 201ymmL.
292     if (LangOpts.C1X)
293       Builder.defineMacro("__STDC_VERSION__", "201001L");
294     else if (LangOpts.C99)
295       Builder.defineMacro("__STDC_VERSION__", "199901L");
296     else if (!LangOpts.GNUMode && LangOpts.Digraphs)
297       Builder.defineMacro("__STDC_VERSION__", "199409L");
298   } else {
299     if (LangOpts.GNUMode)
300       Builder.defineMacro("__cplusplus");
301     else {
302       // C++0x [cpp.predefined]p1:
303       //   The name_ _cplusplus is defined to the value 201103L when compiling a
304       //   C++ translation unit.
305       if (LangOpts.CPlusPlus0x)
306         Builder.defineMacro("__cplusplus", "201103L");
307       // C++03 [cpp.predefined]p1:
308       //   The name_ _cplusplus is defined to the value 199711L when compiling a
309       //   C++ translation unit.
310       else
311         Builder.defineMacro("__cplusplus", "199711L");
312     }
313   }
314 
315   if (LangOpts.ObjC1)
316     Builder.defineMacro("__OBJC__");
317 
318   // Not "standard" per se, but available even with the -undef flag.
319   if (LangOpts.AsmPreprocessor)
320     Builder.defineMacro("__ASSEMBLER__");
321 }
322 
323 static void InitializePredefinedMacros(const TargetInfo &TI,
324                                        const LangOptions &LangOpts,
325                                        const FrontendOptions &FEOpts,
326                                        MacroBuilder &Builder) {
327   // Compiler version introspection macros.
328   Builder.defineMacro("__llvm__");  // LLVM Backend
329   Builder.defineMacro("__clang__"); // Clang Frontend
330 #define TOSTR2(X) #X
331 #define TOSTR(X) TOSTR2(X)
332   Builder.defineMacro("__clang_major__", TOSTR(CLANG_VERSION_MAJOR));
333   Builder.defineMacro("__clang_minor__", TOSTR(CLANG_VERSION_MINOR));
334 #ifdef CLANG_VERSION_PATCHLEVEL
335   Builder.defineMacro("__clang_patchlevel__", TOSTR(CLANG_VERSION_PATCHLEVEL));
336 #else
337   Builder.defineMacro("__clang_patchlevel__", "0");
338 #endif
339   Builder.defineMacro("__clang_version__",
340                       "\"" CLANG_VERSION_STRING " ("
341                       + getClangFullRepositoryVersion() + ")\"");
342 #undef TOSTR
343 #undef TOSTR2
344   // Currently claim to be compatible with GCC 4.2.1-5621.
345   Builder.defineMacro("__GNUC_MINOR__", "2");
346   Builder.defineMacro("__GNUC_PATCHLEVEL__", "1");
347   Builder.defineMacro("__GNUC__", "4");
348   Builder.defineMacro("__GXX_ABI_VERSION", "1002");
349 
350   // As sad as it is, enough software depends on the __VERSION__ for version
351   // checks that it is necessary to report 4.2.1 (the base GCC version we claim
352   // compatibility with) first.
353   Builder.defineMacro("__VERSION__", "\"4.2.1 Compatible " +
354                       Twine(getClangFullCPPVersion()) + "\"");
355 
356   // Initialize language-specific preprocessor defines.
357 
358   // Standard conforming mode?
359   if (!LangOpts.GNUMode)
360     Builder.defineMacro("__STRICT_ANSI__");
361 
362   if (LangOpts.CPlusPlus0x)
363     Builder.defineMacro("__GXX_EXPERIMENTAL_CXX0X__");
364 
365   if (LangOpts.ObjC1) {
366     if (LangOpts.ObjCNonFragileABI) {
367       Builder.defineMacro("__OBJC2__");
368 
369       if (LangOpts.ObjCExceptions)
370         Builder.defineMacro("OBJC_ZEROCOST_EXCEPTIONS");
371     }
372 
373     if (LangOpts.getGC() != LangOptions::NonGC)
374       Builder.defineMacro("__OBJC_GC__");
375 
376     if (LangOpts.NeXTRuntime)
377       Builder.defineMacro("__NEXT_RUNTIME__");
378   }
379 
380   // darwin_constant_cfstrings controls this. This is also dependent
381   // on other things like the runtime I believe.  This is set even for C code.
382   if (!LangOpts.NoConstantCFStrings)
383       Builder.defineMacro("__CONSTANT_CFSTRINGS__");
384 
385   if (LangOpts.ObjC2)
386     Builder.defineMacro("OBJC_NEW_PROPERTIES");
387 
388   if (LangOpts.PascalStrings)
389     Builder.defineMacro("__PASCAL_STRINGS__");
390 
391   if (LangOpts.Blocks) {
392     Builder.defineMacro("__block", "__attribute__((__blocks__(byref)))");
393     Builder.defineMacro("__BLOCKS__");
394   }
395 
396   if (LangOpts.CXXExceptions)
397     Builder.defineMacro("__EXCEPTIONS");
398   if (LangOpts.RTTI)
399     Builder.defineMacro("__GXX_RTTI");
400   if (LangOpts.SjLjExceptions)
401     Builder.defineMacro("__USING_SJLJ_EXCEPTIONS__");
402 
403   if (LangOpts.Deprecated)
404     Builder.defineMacro("__DEPRECATED");
405 
406   if (LangOpts.CPlusPlus) {
407     Builder.defineMacro("__GNUG__", "4");
408     Builder.defineMacro("__GXX_WEAK__");
409     Builder.defineMacro("__private_extern__", "extern");
410   }
411 
412   if (LangOpts.MicrosoftExt) {
413     // Both __PRETTY_FUNCTION__ and __FUNCTION__ are GCC extensions, however
414     // VC++ appears to only like __FUNCTION__.
415     Builder.defineMacro("__PRETTY_FUNCTION__", "__FUNCTION__");
416     // Work around some issues with Visual C++ headerws.
417     if (LangOpts.CPlusPlus) {
418       // Since we define wchar_t in C++ mode.
419       Builder.defineMacro("_WCHAR_T_DEFINED");
420       Builder.defineMacro("_NATIVE_WCHAR_T_DEFINED");
421       // FIXME: Support Microsoft's __identifier extension in the lexer.
422       Builder.append("#define __identifier(x) x");
423       Builder.append("class type_info;");
424     }
425 
426     if (LangOpts.CPlusPlus0x) {
427       Builder.defineMacro("_HAS_CHAR16_T_LANGUAGE_SUPPORT", "1");
428     }
429   }
430 
431   if (LangOpts.Optimize)
432     Builder.defineMacro("__OPTIMIZE__");
433   if (LangOpts.OptimizeSize)
434     Builder.defineMacro("__OPTIMIZE_SIZE__");
435 
436   // Initialize target-specific preprocessor defines.
437 
438   // Define type sizing macros based on the target properties.
439   assert(TI.getCharWidth() == 8 && "Only support 8-bit char so far");
440   Builder.defineMacro("__CHAR_BIT__", "8");
441 
442   DefineTypeSize("__SCHAR_MAX__", TI.getCharWidth(), "", true, Builder);
443   DefineTypeSize("__SHRT_MAX__", TargetInfo::SignedShort, TI, Builder);
444   DefineTypeSize("__INT_MAX__", TargetInfo::SignedInt, TI, Builder);
445   DefineTypeSize("__LONG_MAX__", TargetInfo::SignedLong, TI, Builder);
446   DefineTypeSize("__LONG_LONG_MAX__", TargetInfo::SignedLongLong, TI, Builder);
447   DefineTypeSize("__WCHAR_MAX__", TI.getWCharType(), TI, Builder);
448   DefineTypeSize("__INTMAX_MAX__", TI.getIntMaxType(), TI, Builder);
449 
450   DefineTypeSizeof("__SIZEOF_DOUBLE__", TI.getDoubleWidth(), TI, Builder);
451   DefineTypeSizeof("__SIZEOF_FLOAT__", TI.getFloatWidth(), TI, Builder);
452   DefineTypeSizeof("__SIZEOF_INT__", TI.getIntWidth(), TI, Builder);
453   DefineTypeSizeof("__SIZEOF_LONG__", TI.getLongWidth(), TI, Builder);
454   DefineTypeSizeof("__SIZEOF_LONG_DOUBLE__",TI.getLongDoubleWidth(),TI,Builder);
455   DefineTypeSizeof("__SIZEOF_LONG_LONG__", TI.getLongLongWidth(), TI, Builder);
456   DefineTypeSizeof("__SIZEOF_POINTER__", TI.getPointerWidth(0), TI, Builder);
457   DefineTypeSizeof("__SIZEOF_SHORT__", TI.getShortWidth(), TI, Builder);
458   DefineTypeSizeof("__SIZEOF_PTRDIFF_T__",
459                    TI.getTypeWidth(TI.getPtrDiffType(0)), TI, Builder);
460   DefineTypeSizeof("__SIZEOF_SIZE_T__",
461                    TI.getTypeWidth(TI.getSizeType()), TI, Builder);
462   DefineTypeSizeof("__SIZEOF_WCHAR_T__",
463                    TI.getTypeWidth(TI.getWCharType()), TI, Builder);
464   DefineTypeSizeof("__SIZEOF_WINT_T__",
465                    TI.getTypeWidth(TI.getWIntType()), TI, Builder);
466 
467   DefineType("__INTMAX_TYPE__", TI.getIntMaxType(), Builder);
468   DefineType("__UINTMAX_TYPE__", TI.getUIntMaxType(), Builder);
469   DefineTypeWidth("__INTMAX_WIDTH__",  TI.getIntMaxType(), TI, Builder);
470   DefineType("__PTRDIFF_TYPE__", TI.getPtrDiffType(0), Builder);
471   DefineTypeWidth("__PTRDIFF_WIDTH__", TI.getPtrDiffType(0), TI, Builder);
472   DefineType("__INTPTR_TYPE__", TI.getIntPtrType(), Builder);
473   DefineTypeWidth("__INTPTR_WIDTH__", TI.getIntPtrType(), TI, Builder);
474   DefineType("__SIZE_TYPE__", TI.getSizeType(), Builder);
475   DefineTypeWidth("__SIZE_WIDTH__", TI.getSizeType(), TI, Builder);
476   DefineType("__WCHAR_TYPE__", TI.getWCharType(), Builder);
477   DefineTypeWidth("__WCHAR_WIDTH__", TI.getWCharType(), TI, Builder);
478   DefineType("__WINT_TYPE__", TI.getWIntType(), Builder);
479   DefineTypeWidth("__WINT_WIDTH__", TI.getWIntType(), TI, Builder);
480   DefineTypeWidth("__SIG_ATOMIC_WIDTH__", TI.getSigAtomicType(), TI, Builder);
481   DefineType("__CHAR16_TYPE__", TI.getChar16Type(), Builder);
482   DefineType("__CHAR32_TYPE__", TI.getChar32Type(), Builder);
483 
484   DefineFloatMacros(Builder, "FLT", &TI.getFloatFormat());
485   DefineFloatMacros(Builder, "DBL", &TI.getDoubleFormat());
486   DefineFloatMacros(Builder, "LDBL", &TI.getLongDoubleFormat());
487 
488   // Define a __POINTER_WIDTH__ macro for stdint.h.
489   Builder.defineMacro("__POINTER_WIDTH__",
490                       Twine((int)TI.getPointerWidth(0)));
491 
492   if (!LangOpts.CharIsSigned)
493     Builder.defineMacro("__CHAR_UNSIGNED__");
494 
495   if (!TargetInfo::isTypeSigned(TI.getWIntType()))
496     Builder.defineMacro("__WINT_UNSIGNED__");
497 
498   // Define exact-width integer types for stdint.h
499   Builder.defineMacro("__INT" + Twine(TI.getCharWidth()) + "_TYPE__",
500                       "char");
501 
502   if (TI.getShortWidth() > TI.getCharWidth())
503     DefineExactWidthIntType(TargetInfo::SignedShort, TI, Builder);
504 
505   if (TI.getIntWidth() > TI.getShortWidth())
506     DefineExactWidthIntType(TargetInfo::SignedInt, TI, Builder);
507 
508   if (TI.getLongWidth() > TI.getIntWidth())
509     DefineExactWidthIntType(TargetInfo::SignedLong, TI, Builder);
510 
511   if (TI.getLongLongWidth() > TI.getLongWidth())
512     DefineExactWidthIntType(TargetInfo::SignedLongLong, TI, Builder);
513 
514   // Add __builtin_va_list typedef.
515   Builder.append(TI.getVAListDeclaration());
516 
517   if (const char *Prefix = TI.getUserLabelPrefix())
518     Builder.defineMacro("__USER_LABEL_PREFIX__", Prefix);
519 
520   // Build configuration options.  FIXME: these should be controlled by
521   // command line options or something.
522   Builder.defineMacro("__FINITE_MATH_ONLY__", "0");
523 
524   if (LangOpts.GNUInline)
525     Builder.defineMacro("__GNUC_GNU_INLINE__");
526   else
527     Builder.defineMacro("__GNUC_STDC_INLINE__");
528 
529   if (LangOpts.NoInline)
530     Builder.defineMacro("__NO_INLINE__");
531 
532   if (unsigned PICLevel = LangOpts.PICLevel) {
533     Builder.defineMacro("__PIC__", Twine(PICLevel));
534     Builder.defineMacro("__pic__", Twine(PICLevel));
535   }
536 
537   // Macros to control C99 numerics and <float.h>
538   Builder.defineMacro("__FLT_EVAL_METHOD__", "0");
539   Builder.defineMacro("__FLT_RADIX__", "2");
540   int Dig = PickFP(&TI.getLongDoubleFormat(), -1/*FIXME*/, 17, 21, 33, 36);
541   Builder.defineMacro("__DECIMAL_DIG__", Twine(Dig));
542 
543   if (LangOpts.getStackProtector() == LangOptions::SSPOn)
544     Builder.defineMacro("__SSP__");
545   else if (LangOpts.getStackProtector() == LangOptions::SSPReq)
546     Builder.defineMacro("__SSP_ALL__", "2");
547 
548   if (FEOpts.ProgramAction == frontend::RewriteObjC)
549     Builder.defineMacro("__weak", "__attribute__((objc_gc(weak)))");
550 
551   // Define a macro that exists only when using the static analyzer.
552   if (FEOpts.ProgramAction == frontend::RunAnalysis)
553     Builder.defineMacro("__clang_analyzer__");
554 
555   if (LangOpts.FastRelaxedMath)
556     Builder.defineMacro("__FAST_RELAXED_MATH__");
557 
558   if (LangOpts.ObjCAutoRefCount) {
559     Builder.defineMacro("__weak", "__attribute__((objc_ownership(weak)))");
560     Builder.defineMacro("__strong", "__attribute__((objc_ownership(strong)))");
561     Builder.defineMacro("__autoreleasing",
562                         "__attribute__((objc_ownership(autoreleasing)))");
563     Builder.defineMacro("__unsafe_unretained",
564                         "__attribute__((objc_ownership(none)))");
565   }
566 
567   // Get other target #defines.
568   TI.getTargetDefines(LangOpts, Builder);
569 }
570 
571 // Initialize the remapping of files to alternative contents, e.g.,
572 // those specified through other files.
573 static void InitializeFileRemapping(DiagnosticsEngine &Diags,
574                                     SourceManager &SourceMgr,
575                                     FileManager &FileMgr,
576                                     const PreprocessorOptions &InitOpts) {
577   // Remap files in the source manager (with buffers).
578   for (PreprocessorOptions::const_remapped_file_buffer_iterator
579          Remap = InitOpts.remapped_file_buffer_begin(),
580          RemapEnd = InitOpts.remapped_file_buffer_end();
581        Remap != RemapEnd;
582        ++Remap) {
583     // Create the file entry for the file that we're mapping from.
584     const FileEntry *FromFile = FileMgr.getVirtualFile(Remap->first,
585                                                 Remap->second->getBufferSize(),
586                                                        0);
587     if (!FromFile) {
588       Diags.Report(diag::err_fe_remap_missing_from_file)
589         << Remap->first;
590       if (!InitOpts.RetainRemappedFileBuffers)
591         delete Remap->second;
592       continue;
593     }
594 
595     // Override the contents of the "from" file with the contents of
596     // the "to" file.
597     SourceMgr.overrideFileContents(FromFile, Remap->second,
598                                    InitOpts.RetainRemappedFileBuffers);
599   }
600 
601   // Remap files in the source manager (with other files).
602   for (PreprocessorOptions::const_remapped_file_iterator
603          Remap = InitOpts.remapped_file_begin(),
604          RemapEnd = InitOpts.remapped_file_end();
605        Remap != RemapEnd;
606        ++Remap) {
607     // Find the file that we're mapping to.
608     const FileEntry *ToFile = FileMgr.getFile(Remap->second);
609     if (!ToFile) {
610       Diags.Report(diag::err_fe_remap_missing_to_file)
611       << Remap->first << Remap->second;
612       continue;
613     }
614 
615     // Create the file entry for the file that we're mapping from.
616     const FileEntry *FromFile = FileMgr.getVirtualFile(Remap->first,
617                                                        ToFile->getSize(), 0);
618     if (!FromFile) {
619       Diags.Report(diag::err_fe_remap_missing_from_file)
620       << Remap->first;
621       continue;
622     }
623 
624     // Override the contents of the "from" file with the contents of
625     // the "to" file.
626     SourceMgr.overrideFileContents(FromFile, ToFile);
627   }
628 
629   SourceMgr.setOverridenFilesKeepOriginalName(
630                                         InitOpts.RemappedFilesKeepOriginalName);
631 }
632 
633 /// InitializePreprocessor - Initialize the preprocessor getting it and the
634 /// environment ready to process a single file. This returns true on error.
635 ///
636 void clang::InitializePreprocessor(Preprocessor &PP,
637                                    const PreprocessorOptions &InitOpts,
638                                    const HeaderSearchOptions &HSOpts,
639                                    const FrontendOptions &FEOpts) {
640   const LangOptions &LangOpts = PP.getLangOptions();
641   std::string PredefineBuffer;
642   PredefineBuffer.reserve(4080);
643   llvm::raw_string_ostream Predefines(PredefineBuffer);
644   MacroBuilder Builder(Predefines);
645 
646   InitializeFileRemapping(PP.getDiagnostics(), PP.getSourceManager(),
647                           PP.getFileManager(), InitOpts);
648 
649   // Specify whether the preprocessor should replace #include/#import with
650   // module imports when plausible.
651   PP.setAutoModuleImport(InitOpts.AutoModuleImport);
652 
653   // Emit line markers for various builtin sections of the file.  We don't do
654   // this in asm preprocessor mode, because "# 4" is not a line marker directive
655   // in this mode.
656   if (!PP.getLangOptions().AsmPreprocessor)
657     Builder.append("# 1 \"<built-in>\" 3");
658 
659   // Install things like __POWERPC__, __GNUC__, etc into the macro table.
660   if (InitOpts.UsePredefines) {
661     InitializePredefinedMacros(PP.getTargetInfo(), LangOpts, FEOpts, Builder);
662 
663     // Install definitions to make Objective-C++ ARC work well with various
664     // C++ Standard Library implementations.
665     if (LangOpts.ObjC1 && LangOpts.CPlusPlus && LangOpts.ObjCAutoRefCount) {
666       switch (InitOpts.ObjCXXARCStandardLibrary) {
667       case ARCXX_nolib:
668         case ARCXX_libcxx:
669         break;
670 
671       case ARCXX_libstdcxx:
672         AddObjCXXARCLibstdcxxDefines(LangOpts, Builder);
673         break;
674       }
675     }
676   }
677 
678   // Even with predefines off, some macros are still predefined.
679   // These should all be defined in the preprocessor according to the
680   // current language configuration.
681   InitializeStandardPredefinedMacros(PP.getTargetInfo(), PP.getLangOptions(),
682                                      FEOpts, Builder);
683 
684   // Add on the predefines from the driver.  Wrap in a #line directive to report
685   // that they come from the command line.
686   if (!PP.getLangOptions().AsmPreprocessor)
687     Builder.append("# 1 \"<command line>\" 1");
688 
689   // Process #define's and #undef's in the order they are given.
690   for (unsigned i = 0, e = InitOpts.Macros.size(); i != e; ++i) {
691     if (InitOpts.Macros[i].second)  // isUndef
692       Builder.undefineMacro(InitOpts.Macros[i].first);
693     else
694       DefineBuiltinMacro(Builder, InitOpts.Macros[i].first,
695                          PP.getDiagnostics());
696   }
697 
698   // If -imacros are specified, include them now.  These are processed before
699   // any -include directives.
700   for (unsigned i = 0, e = InitOpts.MacroIncludes.size(); i != e; ++i)
701     AddImplicitIncludeMacros(Builder, InitOpts.MacroIncludes[i],
702                              PP.getFileManager());
703 
704   // Process -include directives.
705   for (unsigned i = 0, e = InitOpts.Includes.size(); i != e; ++i) {
706     const std::string &Path = InitOpts.Includes[i];
707     if (Path == InitOpts.ImplicitPTHInclude)
708       AddImplicitIncludePTH(Builder, PP, Path);
709     else
710       AddImplicitInclude(Builder, Path, PP.getFileManager());
711   }
712 
713   // Exit the command line and go back to <built-in> (2 is LC_LEAVE).
714   if (!PP.getLangOptions().AsmPreprocessor)
715     Builder.append("# 1 \"<built-in>\" 2");
716 
717   // Instruct the preprocessor to skip the preamble.
718   PP.setSkipMainFilePreamble(InitOpts.PrecompiledPreambleBytes.first,
719                              InitOpts.PrecompiledPreambleBytes.second);
720 
721   // Copy PredefinedBuffer into the Preprocessor.
722   PP.setPredefines(Predefines.str());
723 
724   // Initialize the header search object.
725   ApplyHeaderSearchOptions(PP.getHeaderSearchInfo(), HSOpts,
726                            PP.getLangOptions(),
727                            PP.getTargetInfo().getTriple());
728 }
729