xref: /llvm-project/clang/lib/Frontend/InitPreprocessor.cpp (revision 49a2790fb329c5cf27d9735b97ef70a6760921e4)
1 //===--- InitPreprocessor.cpp - PP initialization code. ---------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file implements the clang::InitializePreprocessor function.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "clang/Frontend/Utils.h"
15 #include "clang/Basic/FileManager.h"
16 #include "clang/Basic/MacroBuilder.h"
17 #include "clang/Basic/SourceManager.h"
18 #include "clang/Basic/TargetInfo.h"
19 #include "clang/Basic/Version.h"
20 #include "clang/Frontend/FrontendDiagnostic.h"
21 #include "clang/Frontend/FrontendOptions.h"
22 #include "clang/Lex/HeaderSearch.h"
23 #include "clang/Lex/Preprocessor.h"
24 #include "clang/Lex/PreprocessorOptions.h"
25 #include "clang/Serialization/ASTReader.h"
26 #include "llvm/ADT/APFloat.h"
27 #include "llvm/Support/FileSystem.h"
28 #include "llvm/Support/MemoryBuffer.h"
29 #include "llvm/Support/Path.h"
30 using namespace clang;
31 
32 static bool MacroBodyEndsInBackslash(StringRef MacroBody) {
33   while (!MacroBody.empty() && isWhitespace(MacroBody.back()))
34     MacroBody = MacroBody.drop_back();
35   return !MacroBody.empty() && MacroBody.back() == '\\';
36 }
37 
38 // Append a #define line to Buf for Macro.  Macro should be of the form XXX,
39 // in which case we emit "#define XXX 1" or "XXX=Y z W" in which case we emit
40 // "#define XXX Y z W".  To get a #define with no value, use "XXX=".
41 static void DefineBuiltinMacro(MacroBuilder &Builder, StringRef Macro,
42                                DiagnosticsEngine &Diags) {
43   std::pair<StringRef, StringRef> MacroPair = Macro.split('=');
44   StringRef MacroName = MacroPair.first;
45   StringRef MacroBody = MacroPair.second;
46   if (MacroName.size() != Macro.size()) {
47     // Per GCC -D semantics, the macro ends at \n if it exists.
48     StringRef::size_type End = MacroBody.find_first_of("\n\r");
49     if (End != StringRef::npos)
50       Diags.Report(diag::warn_fe_macro_contains_embedded_newline)
51         << MacroName;
52     MacroBody = MacroBody.substr(0, End);
53     // We handle macro bodies which end in a backslash by appending an extra
54     // backslash+newline.  This makes sure we don't accidentally treat the
55     // backslash as a line continuation marker.
56     if (MacroBodyEndsInBackslash(MacroBody))
57       Builder.defineMacro(MacroName, Twine(MacroBody) + "\\\n");
58     else
59       Builder.defineMacro(MacroName, MacroBody);
60   } else {
61     // Push "macroname 1".
62     Builder.defineMacro(Macro);
63   }
64 }
65 
66 /// AddImplicitInclude - Add an implicit \#include of the specified file to the
67 /// predefines buffer.
68 static void AddImplicitInclude(MacroBuilder &Builder, StringRef File,
69                                FileManager &FileMgr) {
70   Builder.append(Twine("#include \"") +
71                  HeaderSearch::NormalizeDashIncludePath(File, FileMgr) + "\"");
72 }
73 
74 static void AddImplicitIncludeMacros(MacroBuilder &Builder,
75                                      StringRef File,
76                                      FileManager &FileMgr) {
77   Builder.append(Twine("#__include_macros \"") +
78                  HeaderSearch::NormalizeDashIncludePath(File, FileMgr) + "\"");
79   // Marker token to stop the __include_macros fetch loop.
80   Builder.append("##"); // ##?
81 }
82 
83 /// AddImplicitIncludePTH - Add an implicit \#include using the original file
84 /// used to generate a PTH cache.
85 static void AddImplicitIncludePTH(MacroBuilder &Builder, Preprocessor &PP,
86                                   StringRef ImplicitIncludePTH) {
87   PTHManager *P = PP.getPTHManager();
88   // Null check 'P' in the corner case where it couldn't be created.
89   const char *OriginalFile = P ? P->getOriginalSourceFile() : nullptr;
90 
91   if (!OriginalFile) {
92     PP.getDiagnostics().Report(diag::err_fe_pth_file_has_no_source_header)
93       << ImplicitIncludePTH;
94     return;
95   }
96 
97   AddImplicitInclude(Builder, OriginalFile, PP.getFileManager());
98 }
99 
100 /// \brief Add an implicit \#include using the original file used to generate
101 /// a PCH file.
102 static void AddImplicitIncludePCH(MacroBuilder &Builder, Preprocessor &PP,
103                                   StringRef ImplicitIncludePCH) {
104   std::string OriginalFile =
105     ASTReader::getOriginalSourceFile(ImplicitIncludePCH, PP.getFileManager(),
106                                      PP.getDiagnostics());
107   if (OriginalFile.empty())
108     return;
109 
110   AddImplicitInclude(Builder, OriginalFile, PP.getFileManager());
111 }
112 
113 /// PickFP - This is used to pick a value based on the FP semantics of the
114 /// specified FP model.
115 template <typename T>
116 static T PickFP(const llvm::fltSemantics *Sem, T IEEESingleVal,
117                 T IEEEDoubleVal, T X87DoubleExtendedVal, T PPCDoubleDoubleVal,
118                 T IEEEQuadVal) {
119   if (Sem == (const llvm::fltSemantics*)&llvm::APFloat::IEEEsingle)
120     return IEEESingleVal;
121   if (Sem == (const llvm::fltSemantics*)&llvm::APFloat::IEEEdouble)
122     return IEEEDoubleVal;
123   if (Sem == (const llvm::fltSemantics*)&llvm::APFloat::x87DoubleExtended)
124     return X87DoubleExtendedVal;
125   if (Sem == (const llvm::fltSemantics*)&llvm::APFloat::PPCDoubleDouble)
126     return PPCDoubleDoubleVal;
127   assert(Sem == (const llvm::fltSemantics*)&llvm::APFloat::IEEEquad);
128   return IEEEQuadVal;
129 }
130 
131 static void DefineFloatMacros(MacroBuilder &Builder, StringRef Prefix,
132                               const llvm::fltSemantics *Sem, StringRef Ext) {
133   const char *DenormMin, *Epsilon, *Max, *Min;
134   DenormMin = PickFP(Sem, "1.40129846e-45", "4.9406564584124654e-324",
135                      "3.64519953188247460253e-4951",
136                      "4.94065645841246544176568792868221e-324",
137                      "6.47517511943802511092443895822764655e-4966");
138   int Digits = PickFP(Sem, 6, 15, 18, 31, 33);
139   Epsilon = PickFP(Sem, "1.19209290e-7", "2.2204460492503131e-16",
140                    "1.08420217248550443401e-19",
141                    "4.94065645841246544176568792868221e-324",
142                    "1.92592994438723585305597794258492732e-34");
143   int MantissaDigits = PickFP(Sem, 24, 53, 64, 106, 113);
144   int Min10Exp = PickFP(Sem, -37, -307, -4931, -291, -4931);
145   int Max10Exp = PickFP(Sem, 38, 308, 4932, 308, 4932);
146   int MinExp = PickFP(Sem, -125, -1021, -16381, -968, -16381);
147   int MaxExp = PickFP(Sem, 128, 1024, 16384, 1024, 16384);
148   Min = PickFP(Sem, "1.17549435e-38", "2.2250738585072014e-308",
149                "3.36210314311209350626e-4932",
150                "2.00416836000897277799610805135016e-292",
151                "3.36210314311209350626267781732175260e-4932");
152   Max = PickFP(Sem, "3.40282347e+38", "1.7976931348623157e+308",
153                "1.18973149535723176502e+4932",
154                "1.79769313486231580793728971405301e+308",
155                "1.18973149535723176508575932662800702e+4932");
156 
157   SmallString<32> DefPrefix;
158   DefPrefix = "__";
159   DefPrefix += Prefix;
160   DefPrefix += "_";
161 
162   Builder.defineMacro(DefPrefix + "DENORM_MIN__", Twine(DenormMin)+Ext);
163   Builder.defineMacro(DefPrefix + "HAS_DENORM__");
164   Builder.defineMacro(DefPrefix + "DIG__", Twine(Digits));
165   Builder.defineMacro(DefPrefix + "EPSILON__", Twine(Epsilon)+Ext);
166   Builder.defineMacro(DefPrefix + "HAS_INFINITY__");
167   Builder.defineMacro(DefPrefix + "HAS_QUIET_NAN__");
168   Builder.defineMacro(DefPrefix + "MANT_DIG__", Twine(MantissaDigits));
169 
170   Builder.defineMacro(DefPrefix + "MAX_10_EXP__", Twine(Max10Exp));
171   Builder.defineMacro(DefPrefix + "MAX_EXP__", Twine(MaxExp));
172   Builder.defineMacro(DefPrefix + "MAX__", Twine(Max)+Ext);
173 
174   Builder.defineMacro(DefPrefix + "MIN_10_EXP__","("+Twine(Min10Exp)+")");
175   Builder.defineMacro(DefPrefix + "MIN_EXP__", "("+Twine(MinExp)+")");
176   Builder.defineMacro(DefPrefix + "MIN__", Twine(Min)+Ext);
177 }
178 
179 
180 /// DefineTypeSize - Emit a macro to the predefines buffer that declares a macro
181 /// named MacroName with the max value for a type with width 'TypeWidth' a
182 /// signedness of 'isSigned' and with a value suffix of 'ValSuffix' (e.g. LL).
183 static void DefineTypeSize(StringRef MacroName, unsigned TypeWidth,
184                            StringRef ValSuffix, bool isSigned,
185                            MacroBuilder &Builder) {
186   llvm::APInt MaxVal = isSigned ? llvm::APInt::getSignedMaxValue(TypeWidth)
187                                 : llvm::APInt::getMaxValue(TypeWidth);
188   Builder.defineMacro(MacroName, MaxVal.toString(10, isSigned) + ValSuffix);
189 }
190 
191 /// DefineTypeSize - An overloaded helper that uses TargetInfo to determine
192 /// the width, suffix, and signedness of the given type
193 static void DefineTypeSize(StringRef MacroName, TargetInfo::IntType Ty,
194                            const TargetInfo &TI, MacroBuilder &Builder) {
195   DefineTypeSize(MacroName, TI.getTypeWidth(Ty), TI.getTypeConstantSuffix(Ty),
196                  TI.isTypeSigned(Ty), Builder);
197 }
198 
199 static void DefineType(const Twine &MacroName, TargetInfo::IntType Ty,
200                        MacroBuilder &Builder) {
201   Builder.defineMacro(MacroName, TargetInfo::getTypeName(Ty));
202 }
203 
204 static void DefineTypeWidth(StringRef MacroName, TargetInfo::IntType Ty,
205                             const TargetInfo &TI, MacroBuilder &Builder) {
206   Builder.defineMacro(MacroName, Twine(TI.getTypeWidth(Ty)));
207 }
208 
209 static void DefineTypeSizeof(StringRef MacroName, unsigned BitWidth,
210                              const TargetInfo &TI, MacroBuilder &Builder) {
211   Builder.defineMacro(MacroName,
212                       Twine(BitWidth / TI.getCharWidth()));
213 }
214 
215 static void DefineExactWidthIntType(TargetInfo::IntType Ty,
216                                const TargetInfo &TI, MacroBuilder &Builder) {
217   int TypeWidth = TI.getTypeWidth(Ty);
218 
219   // Use the target specified int64 type, when appropriate, so that [u]int64_t
220   // ends up being defined in terms of the correct type.
221   if (TypeWidth == 64)
222     Ty = TI.getInt64Type();
223 
224   DefineType("__INT" + Twine(TypeWidth) + "_TYPE__", Ty, Builder);
225 
226   StringRef ConstSuffix(TargetInfo::getTypeConstantSuffix(Ty));
227   if (!ConstSuffix.empty())
228     Builder.defineMacro("__INT" + Twine(TypeWidth) + "_C_SUFFIX__",
229                         ConstSuffix);
230 }
231 
232 /// Get the value the ATOMIC_*_LOCK_FREE macro should have for a type with
233 /// the specified properties.
234 static const char *getLockFreeValue(unsigned TypeWidth, unsigned TypeAlign,
235                                     unsigned InlineWidth) {
236   // Fully-aligned, power-of-2 sizes no larger than the inline
237   // width will be inlined as lock-free operations.
238   if (TypeWidth == TypeAlign && (TypeWidth & (TypeWidth - 1)) == 0 &&
239       TypeWidth <= InlineWidth)
240     return "2"; // "always lock free"
241   // We cannot be certain what operations the lib calls might be
242   // able to implement as lock-free on future processors.
243   return "1"; // "sometimes lock free"
244 }
245 
246 /// \brief Add definitions required for a smooth interaction between
247 /// Objective-C++ automated reference counting and libstdc++ (4.2).
248 static void AddObjCXXARCLibstdcxxDefines(const LangOptions &LangOpts,
249                                          MacroBuilder &Builder) {
250   Builder.defineMacro("_GLIBCXX_PREDEFINED_OBJC_ARC_IS_SCALAR");
251 
252   std::string Result;
253   {
254     // Provide specializations for the __is_scalar type trait so that
255     // lifetime-qualified objects are not considered "scalar" types, which
256     // libstdc++ uses as an indicator of the presence of trivial copy, assign,
257     // default-construct, and destruct semantics (none of which hold for
258     // lifetime-qualified objects in ARC).
259     llvm::raw_string_ostream Out(Result);
260 
261     Out << "namespace std {\n"
262         << "\n"
263         << "struct __true_type;\n"
264         << "struct __false_type;\n"
265         << "\n";
266 
267     Out << "template<typename _Tp> struct __is_scalar;\n"
268         << "\n";
269 
270     Out << "template<typename _Tp>\n"
271         << "struct __is_scalar<__attribute__((objc_ownership(strong))) _Tp> {\n"
272         << "  enum { __value = 0 };\n"
273         << "  typedef __false_type __type;\n"
274         << "};\n"
275         << "\n";
276 
277     if (LangOpts.ObjCARCWeak) {
278       Out << "template<typename _Tp>\n"
279           << "struct __is_scalar<__attribute__((objc_ownership(weak))) _Tp> {\n"
280           << "  enum { __value = 0 };\n"
281           << "  typedef __false_type __type;\n"
282           << "};\n"
283           << "\n";
284     }
285 
286     Out << "template<typename _Tp>\n"
287         << "struct __is_scalar<__attribute__((objc_ownership(autoreleasing)))"
288         << " _Tp> {\n"
289         << "  enum { __value = 0 };\n"
290         << "  typedef __false_type __type;\n"
291         << "};\n"
292         << "\n";
293 
294     Out << "}\n";
295   }
296   Builder.append(Result);
297 }
298 
299 static void InitializeStandardPredefinedMacros(const TargetInfo &TI,
300                                                const LangOptions &LangOpts,
301                                                const FrontendOptions &FEOpts,
302                                                MacroBuilder &Builder) {
303   if (!LangOpts.MSVCCompat && !LangOpts.TraditionalCPP)
304     Builder.defineMacro("__STDC__");
305   if (LangOpts.Freestanding)
306     Builder.defineMacro("__STDC_HOSTED__", "0");
307   else
308     Builder.defineMacro("__STDC_HOSTED__");
309 
310   if (!LangOpts.CPlusPlus) {
311     if (LangOpts.C11)
312       Builder.defineMacro("__STDC_VERSION__", "201112L");
313     else if (LangOpts.C99)
314       Builder.defineMacro("__STDC_VERSION__", "199901L");
315     else if (!LangOpts.GNUMode && LangOpts.Digraphs)
316       Builder.defineMacro("__STDC_VERSION__", "199409L");
317   } else {
318     // C++1y [cpp.predefined]p1:
319     //   The name __cplusplus is defined to the value 201402L when compiling a
320     //   C++ translation unit.
321      if (LangOpts.CPlusPlus1y)
322       Builder.defineMacro("__cplusplus", "201402L");
323     // C++11 [cpp.predefined]p1:
324     //   The name __cplusplus is defined to the value 201103L when compiling a
325     //   C++ translation unit.
326     else if (LangOpts.CPlusPlus11)
327       Builder.defineMacro("__cplusplus", "201103L");
328     // C++03 [cpp.predefined]p1:
329     //   The name __cplusplus is defined to the value 199711L when compiling a
330     //   C++ translation unit.
331     else
332       Builder.defineMacro("__cplusplus", "199711L");
333   }
334 
335   // In C11 these are environment macros. In C++11 they are only defined
336   // as part of <cuchar>. To prevent breakage when mixing C and C++
337   // code, define these macros unconditionally. We can define them
338   // unconditionally, as Clang always uses UTF-16 and UTF-32 for 16-bit
339   // and 32-bit character literals.
340   Builder.defineMacro("__STDC_UTF_16__", "1");
341   Builder.defineMacro("__STDC_UTF_32__", "1");
342 
343   if (LangOpts.ObjC1)
344     Builder.defineMacro("__OBJC__");
345 
346   // Not "standard" per se, but available even with the -undef flag.
347   if (LangOpts.AsmPreprocessor)
348     Builder.defineMacro("__ASSEMBLER__");
349 }
350 
351 /// Initialize the predefined C++ language feature test macros defined in
352 /// ISO/IEC JTC1/SC22/WG21 (C++) SD-6: "SG10 Feature Test Recommendations".
353 static void InitializeCPlusPlusFeatureTestMacros(const LangOptions &LangOpts,
354                                                  MacroBuilder &Builder) {
355   // C++11 features.
356   if (LangOpts.CPlusPlus11) {
357     Builder.defineMacro("__cpp_unicode_characters", "200704");
358     Builder.defineMacro("__cpp_raw_strings", "200710");
359     Builder.defineMacro("__cpp_unicode_literals", "200710");
360     Builder.defineMacro("__cpp_user_defined_literals", "200809");
361     Builder.defineMacro("__cpp_lambdas", "200907");
362     Builder.defineMacro("__cpp_constexpr",
363                         LangOpts.CPlusPlus1y ? "201304" : "200704");
364     Builder.defineMacro("__cpp_static_assert", "200410");
365     Builder.defineMacro("__cpp_decltype", "200707");
366     Builder.defineMacro("__cpp_attributes", "200809");
367     Builder.defineMacro("__cpp_rvalue_references", "200610");
368     Builder.defineMacro("__cpp_variadic_templates", "200704");
369   }
370 
371   // C++14 features.
372   if (LangOpts.CPlusPlus1y) {
373     Builder.defineMacro("__cpp_binary_literals", "201304");
374     Builder.defineMacro("__cpp_init_captures", "201304");
375     Builder.defineMacro("__cpp_generic_lambdas", "201304");
376     Builder.defineMacro("__cpp_decltype_auto", "201304");
377     Builder.defineMacro("__cpp_return_type_deduction", "201304");
378     Builder.defineMacro("__cpp_aggregate_nsdmi", "201304");
379     Builder.defineMacro("__cpp_variable_templates", "201304");
380   }
381 }
382 
383 static void InitializePredefinedMacros(const TargetInfo &TI,
384                                        const LangOptions &LangOpts,
385                                        const FrontendOptions &FEOpts,
386                                        MacroBuilder &Builder) {
387   // Compiler version introspection macros.
388   Builder.defineMacro("__llvm__");  // LLVM Backend
389   Builder.defineMacro("__clang__"); // Clang Frontend
390 #define TOSTR2(X) #X
391 #define TOSTR(X) TOSTR2(X)
392   Builder.defineMacro("__clang_major__", TOSTR(CLANG_VERSION_MAJOR));
393   Builder.defineMacro("__clang_minor__", TOSTR(CLANG_VERSION_MINOR));
394 #ifdef CLANG_VERSION_PATCHLEVEL
395   Builder.defineMacro("__clang_patchlevel__", TOSTR(CLANG_VERSION_PATCHLEVEL));
396 #else
397   Builder.defineMacro("__clang_patchlevel__", "0");
398 #endif
399   Builder.defineMacro("__clang_version__",
400                       "\"" CLANG_VERSION_STRING " "
401                       + getClangFullRepositoryVersion() + "\"");
402 #undef TOSTR
403 #undef TOSTR2
404   if (!LangOpts.MSVCCompat) {
405     // Currently claim to be compatible with GCC 4.2.1-5621, but only if we're
406     // not compiling for MSVC compatibility
407     Builder.defineMacro("__GNUC_MINOR__", "2");
408     Builder.defineMacro("__GNUC_PATCHLEVEL__", "1");
409     Builder.defineMacro("__GNUC__", "4");
410     Builder.defineMacro("__GXX_ABI_VERSION", "1002");
411   }
412 
413   // Define macros for the C11 / C++11 memory orderings
414   Builder.defineMacro("__ATOMIC_RELAXED", "0");
415   Builder.defineMacro("__ATOMIC_CONSUME", "1");
416   Builder.defineMacro("__ATOMIC_ACQUIRE", "2");
417   Builder.defineMacro("__ATOMIC_RELEASE", "3");
418   Builder.defineMacro("__ATOMIC_ACQ_REL", "4");
419   Builder.defineMacro("__ATOMIC_SEQ_CST", "5");
420 
421   // Support for #pragma redefine_extname (Sun compatibility)
422   Builder.defineMacro("__PRAGMA_REDEFINE_EXTNAME", "1");
423 
424   // As sad as it is, enough software depends on the __VERSION__ for version
425   // checks that it is necessary to report 4.2.1 (the base GCC version we claim
426   // compatibility with) first.
427   Builder.defineMacro("__VERSION__", "\"4.2.1 Compatible " +
428                       Twine(getClangFullCPPVersion()) + "\"");
429 
430   // Initialize language-specific preprocessor defines.
431 
432   // Standard conforming mode?
433   if (!LangOpts.GNUMode)
434     Builder.defineMacro("__STRICT_ANSI__");
435 
436   if (LangOpts.CPlusPlus11)
437     Builder.defineMacro("__GXX_EXPERIMENTAL_CXX0X__");
438 
439   if (LangOpts.ObjC1) {
440     if (LangOpts.ObjCRuntime.isNonFragile()) {
441       Builder.defineMacro("__OBJC2__");
442 
443       if (LangOpts.ObjCExceptions)
444         Builder.defineMacro("OBJC_ZEROCOST_EXCEPTIONS");
445     }
446 
447     if (LangOpts.getGC() != LangOptions::NonGC)
448       Builder.defineMacro("__OBJC_GC__");
449 
450     if (LangOpts.ObjCRuntime.isNeXTFamily())
451       Builder.defineMacro("__NEXT_RUNTIME__");
452 
453     if (LangOpts.ObjCRuntime.getKind() == ObjCRuntime::ObjFW) {
454       VersionTuple tuple = LangOpts.ObjCRuntime.getVersion();
455 
456       unsigned minor = 0;
457       if (tuple.getMinor().hasValue())
458         minor = tuple.getMinor().getValue();
459 
460       unsigned subminor = 0;
461       if (tuple.getSubminor().hasValue())
462         subminor = tuple.getSubminor().getValue();
463 
464       Builder.defineMacro("__OBJFW_RUNTIME_ABI__",
465                           Twine(tuple.getMajor() * 10000 + minor * 100 +
466                                 subminor));
467     }
468 
469     Builder.defineMacro("IBOutlet", "__attribute__((iboutlet))");
470     Builder.defineMacro("IBOutletCollection(ClassName)",
471                         "__attribute__((iboutletcollection(ClassName)))");
472     Builder.defineMacro("IBAction", "void)__attribute__((ibaction)");
473   }
474 
475   if (LangOpts.CPlusPlus)
476     InitializeCPlusPlusFeatureTestMacros(LangOpts, Builder);
477 
478   // darwin_constant_cfstrings controls this. This is also dependent
479   // on other things like the runtime I believe.  This is set even for C code.
480   if (!LangOpts.NoConstantCFStrings)
481       Builder.defineMacro("__CONSTANT_CFSTRINGS__");
482 
483   if (LangOpts.ObjC2)
484     Builder.defineMacro("OBJC_NEW_PROPERTIES");
485 
486   if (LangOpts.PascalStrings)
487     Builder.defineMacro("__PASCAL_STRINGS__");
488 
489   if (LangOpts.Blocks) {
490     Builder.defineMacro("__block", "__attribute__((__blocks__(byref)))");
491     Builder.defineMacro("__BLOCKS__");
492   }
493 
494   if (LangOpts.CXXExceptions)
495     Builder.defineMacro("__EXCEPTIONS");
496   if (LangOpts.RTTI)
497     Builder.defineMacro("__GXX_RTTI");
498   if (LangOpts.SjLjExceptions)
499     Builder.defineMacro("__USING_SJLJ_EXCEPTIONS__");
500 
501   if (LangOpts.Deprecated)
502     Builder.defineMacro("__DEPRECATED");
503 
504   if (LangOpts.CPlusPlus) {
505     Builder.defineMacro("__GNUG__", "4");
506     Builder.defineMacro("__GXX_WEAK__");
507     Builder.defineMacro("__private_extern__", "extern");
508   }
509 
510   if (LangOpts.MicrosoftExt) {
511     if (LangOpts.WChar) {
512       // wchar_t supported as a keyword.
513       Builder.defineMacro("_WCHAR_T_DEFINED");
514       Builder.defineMacro("_NATIVE_WCHAR_T_DEFINED");
515     }
516   }
517 
518   if (LangOpts.Optimize)
519     Builder.defineMacro("__OPTIMIZE__");
520   if (LangOpts.OptimizeSize)
521     Builder.defineMacro("__OPTIMIZE_SIZE__");
522 
523   if (LangOpts.FastMath)
524     Builder.defineMacro("__FAST_MATH__");
525 
526   // Initialize target-specific preprocessor defines.
527 
528   // __BYTE_ORDER__ was added in GCC 4.6. It's analogous
529   // to the macro __BYTE_ORDER (no trailing underscores)
530   // from glibc's <endian.h> header.
531   // We don't support the PDP-11 as a target, but include
532   // the define so it can still be compared against.
533   Builder.defineMacro("__ORDER_LITTLE_ENDIAN__", "1234");
534   Builder.defineMacro("__ORDER_BIG_ENDIAN__",    "4321");
535   Builder.defineMacro("__ORDER_PDP_ENDIAN__",    "3412");
536   if (TI.isBigEndian()) {
537     Builder.defineMacro("__BYTE_ORDER__", "__ORDER_BIG_ENDIAN__");
538     Builder.defineMacro("__BIG_ENDIAN__");
539   } else {
540     Builder.defineMacro("__BYTE_ORDER__", "__ORDER_LITTLE_ENDIAN__");
541     Builder.defineMacro("__LITTLE_ENDIAN__");
542   }
543 
544   if (TI.getPointerWidth(0) == 64 && TI.getLongWidth() == 64
545       && TI.getIntWidth() == 32) {
546     Builder.defineMacro("_LP64");
547     Builder.defineMacro("__LP64__");
548   }
549 
550   // Define type sizing macros based on the target properties.
551   assert(TI.getCharWidth() == 8 && "Only support 8-bit char so far");
552   Builder.defineMacro("__CHAR_BIT__", "8");
553 
554   DefineTypeSize("__SCHAR_MAX__", TargetInfo::SignedChar, TI, Builder);
555   DefineTypeSize("__SHRT_MAX__", TargetInfo::SignedShort, TI, Builder);
556   DefineTypeSize("__INT_MAX__", TargetInfo::SignedInt, TI, Builder);
557   DefineTypeSize("__LONG_MAX__", TargetInfo::SignedLong, TI, Builder);
558   DefineTypeSize("__LONG_LONG_MAX__", TargetInfo::SignedLongLong, TI, Builder);
559   DefineTypeSize("__WCHAR_MAX__", TI.getWCharType(), TI, Builder);
560   DefineTypeSize("__INTMAX_MAX__", TI.getIntMaxType(), TI, Builder);
561   DefineTypeSize("__SIZE_MAX__", TI.getSizeType(), TI, Builder);
562 
563   DefineTypeSizeof("__SIZEOF_DOUBLE__", TI.getDoubleWidth(), TI, Builder);
564   DefineTypeSizeof("__SIZEOF_FLOAT__", TI.getFloatWidth(), TI, Builder);
565   DefineTypeSizeof("__SIZEOF_INT__", TI.getIntWidth(), TI, Builder);
566   DefineTypeSizeof("__SIZEOF_LONG__", TI.getLongWidth(), TI, Builder);
567   DefineTypeSizeof("__SIZEOF_LONG_DOUBLE__",TI.getLongDoubleWidth(),TI,Builder);
568   DefineTypeSizeof("__SIZEOF_LONG_LONG__", TI.getLongLongWidth(), TI, Builder);
569   DefineTypeSizeof("__SIZEOF_POINTER__", TI.getPointerWidth(0), TI, Builder);
570   DefineTypeSizeof("__SIZEOF_SHORT__", TI.getShortWidth(), TI, Builder);
571   DefineTypeSizeof("__SIZEOF_PTRDIFF_T__",
572                    TI.getTypeWidth(TI.getPtrDiffType(0)), TI, Builder);
573   DefineTypeSizeof("__SIZEOF_SIZE_T__",
574                    TI.getTypeWidth(TI.getSizeType()), TI, Builder);
575   DefineTypeSizeof("__SIZEOF_WCHAR_T__",
576                    TI.getTypeWidth(TI.getWCharType()), TI, Builder);
577   DefineTypeSizeof("__SIZEOF_WINT_T__",
578                    TI.getTypeWidth(TI.getWIntType()), TI, Builder);
579   if (TI.hasInt128Type())
580     DefineTypeSizeof("__SIZEOF_INT128__", 128, TI, Builder);
581 
582   DefineType("__INTMAX_TYPE__", TI.getIntMaxType(), Builder);
583   DefineType("__UINTMAX_TYPE__", TI.getUIntMaxType(), Builder);
584   DefineTypeWidth("__INTMAX_WIDTH__",  TI.getIntMaxType(), TI, Builder);
585   DefineType("__PTRDIFF_TYPE__", TI.getPtrDiffType(0), Builder);
586   DefineTypeWidth("__PTRDIFF_WIDTH__", TI.getPtrDiffType(0), TI, Builder);
587   DefineType("__INTPTR_TYPE__", TI.getIntPtrType(), Builder);
588   DefineTypeWidth("__INTPTR_WIDTH__", TI.getIntPtrType(), TI, Builder);
589   DefineType("__SIZE_TYPE__", TI.getSizeType(), Builder);
590   DefineTypeWidth("__SIZE_WIDTH__", TI.getSizeType(), TI, Builder);
591   DefineType("__WCHAR_TYPE__", TI.getWCharType(), Builder);
592   DefineTypeWidth("__WCHAR_WIDTH__", TI.getWCharType(), TI, Builder);
593   DefineType("__WINT_TYPE__", TI.getWIntType(), Builder);
594   DefineTypeWidth("__WINT_WIDTH__", TI.getWIntType(), TI, Builder);
595   DefineTypeWidth("__SIG_ATOMIC_WIDTH__", TI.getSigAtomicType(), TI, Builder);
596   DefineType("__CHAR16_TYPE__", TI.getChar16Type(), Builder);
597   DefineType("__CHAR32_TYPE__", TI.getChar32Type(), Builder);
598 
599   DefineFloatMacros(Builder, "FLT", &TI.getFloatFormat(), "F");
600   DefineFloatMacros(Builder, "DBL", &TI.getDoubleFormat(), "");
601   DefineFloatMacros(Builder, "LDBL", &TI.getLongDoubleFormat(), "L");
602 
603   // Define a __POINTER_WIDTH__ macro for stdint.h.
604   Builder.defineMacro("__POINTER_WIDTH__",
605                       Twine((int)TI.getPointerWidth(0)));
606 
607   if (!LangOpts.CharIsSigned)
608     Builder.defineMacro("__CHAR_UNSIGNED__");
609 
610   if (!TargetInfo::isTypeSigned(TI.getWCharType()))
611     Builder.defineMacro("__WCHAR_UNSIGNED__");
612 
613   if (!TargetInfo::isTypeSigned(TI.getWIntType()))
614     Builder.defineMacro("__WINT_UNSIGNED__");
615 
616   // Define exact-width integer types for stdint.h
617   Builder.defineMacro("__INT" + Twine(TI.getCharWidth()) + "_TYPE__",
618                       "char");
619 
620   if (TI.getShortWidth() > TI.getCharWidth())
621     DefineExactWidthIntType(TargetInfo::SignedShort, TI, Builder);
622 
623   if (TI.getIntWidth() > TI.getShortWidth())
624     DefineExactWidthIntType(TargetInfo::SignedInt, TI, Builder);
625 
626   if (TI.getLongWidth() > TI.getIntWidth())
627     DefineExactWidthIntType(TargetInfo::SignedLong, TI, Builder);
628 
629   if (TI.getLongLongWidth() > TI.getLongWidth())
630     DefineExactWidthIntType(TargetInfo::SignedLongLong, TI, Builder);
631 
632   if (const char *Prefix = TI.getUserLabelPrefix())
633     Builder.defineMacro("__USER_LABEL_PREFIX__", Prefix);
634 
635   if (LangOpts.FastMath || LangOpts.FiniteMathOnly)
636     Builder.defineMacro("__FINITE_MATH_ONLY__", "1");
637   else
638     Builder.defineMacro("__FINITE_MATH_ONLY__", "0");
639 
640   if (LangOpts.GNUInline)
641     Builder.defineMacro("__GNUC_GNU_INLINE__");
642   else
643     Builder.defineMacro("__GNUC_STDC_INLINE__");
644 
645   // The value written by __atomic_test_and_set.
646   // FIXME: This is target-dependent.
647   Builder.defineMacro("__GCC_ATOMIC_TEST_AND_SET_TRUEVAL", "1");
648 
649   // Used by libstdc++ to implement ATOMIC_<foo>_LOCK_FREE.
650   unsigned InlineWidthBits = TI.getMaxAtomicInlineWidth();
651 #define DEFINE_LOCK_FREE_MACRO(TYPE, Type) \
652   Builder.defineMacro("__GCC_ATOMIC_" #TYPE "_LOCK_FREE", \
653                       getLockFreeValue(TI.get##Type##Width(), \
654                                        TI.get##Type##Align(), \
655                                        InlineWidthBits));
656   DEFINE_LOCK_FREE_MACRO(BOOL, Bool);
657   DEFINE_LOCK_FREE_MACRO(CHAR, Char);
658   DEFINE_LOCK_FREE_MACRO(CHAR16_T, Char16);
659   DEFINE_LOCK_FREE_MACRO(CHAR32_T, Char32);
660   DEFINE_LOCK_FREE_MACRO(WCHAR_T, WChar);
661   DEFINE_LOCK_FREE_MACRO(SHORT, Short);
662   DEFINE_LOCK_FREE_MACRO(INT, Int);
663   DEFINE_LOCK_FREE_MACRO(LONG, Long);
664   DEFINE_LOCK_FREE_MACRO(LLONG, LongLong);
665   Builder.defineMacro("__GCC_ATOMIC_POINTER_LOCK_FREE",
666                       getLockFreeValue(TI.getPointerWidth(0),
667                                        TI.getPointerAlign(0),
668                                        InlineWidthBits));
669 #undef DEFINE_LOCK_FREE_MACRO
670 
671   if (LangOpts.NoInlineDefine)
672     Builder.defineMacro("__NO_INLINE__");
673 
674   if (unsigned PICLevel = LangOpts.PICLevel) {
675     Builder.defineMacro("__PIC__", Twine(PICLevel));
676     Builder.defineMacro("__pic__", Twine(PICLevel));
677   }
678   if (unsigned PIELevel = LangOpts.PIELevel) {
679     Builder.defineMacro("__PIE__", Twine(PIELevel));
680     Builder.defineMacro("__pie__", Twine(PIELevel));
681   }
682 
683   // Macros to control C99 numerics and <float.h>
684   Builder.defineMacro("__FLT_EVAL_METHOD__", Twine(TI.getFloatEvalMethod()));
685   Builder.defineMacro("__FLT_RADIX__", "2");
686   int Dig = PickFP(&TI.getLongDoubleFormat(), -1/*FIXME*/, 17, 21, 33, 36);
687   Builder.defineMacro("__DECIMAL_DIG__", Twine(Dig));
688 
689   if (LangOpts.getStackProtector() == LangOptions::SSPOn)
690     Builder.defineMacro("__SSP__");
691   else if (LangOpts.getStackProtector() == LangOptions::SSPStrong)
692     Builder.defineMacro("__SSP_STRONG__", "2");
693   else if (LangOpts.getStackProtector() == LangOptions::SSPReq)
694     Builder.defineMacro("__SSP_ALL__", "3");
695 
696   if (FEOpts.ProgramAction == frontend::RewriteObjC)
697     Builder.defineMacro("__weak", "__attribute__((objc_gc(weak)))");
698 
699   // Define a macro that exists only when using the static analyzer.
700   if (FEOpts.ProgramAction == frontend::RunAnalysis)
701     Builder.defineMacro("__clang_analyzer__");
702 
703   if (LangOpts.FastRelaxedMath)
704     Builder.defineMacro("__FAST_RELAXED_MATH__");
705 
706   if (LangOpts.ObjCAutoRefCount) {
707     Builder.defineMacro("__weak", "__attribute__((objc_ownership(weak)))");
708     Builder.defineMacro("__strong", "__attribute__((objc_ownership(strong)))");
709     Builder.defineMacro("__autoreleasing",
710                         "__attribute__((objc_ownership(autoreleasing)))");
711     Builder.defineMacro("__unsafe_unretained",
712                         "__attribute__((objc_ownership(none)))");
713   }
714 
715   // OpenMP definition
716   if (LangOpts.OpenMP) {
717     // OpenMP 2.2:
718     //   In implementations that support a preprocessor, the _OPENMP
719     //   macro name is defined to have the decimal value yyyymm where
720     //   yyyy and mm are the year and the month designations of the
721     //   version of the OpenMP API that the implementation support.
722     Builder.defineMacro("_OPENMP", "201307");
723   }
724 
725   // Get other target #defines.
726   TI.getTargetDefines(LangOpts, Builder);
727 }
728 
729 // Initialize the remapping of files to alternative contents, e.g.,
730 // those specified through other files.
731 static void InitializeFileRemapping(DiagnosticsEngine &Diags,
732                                     SourceManager &SourceMgr,
733                                     FileManager &FileMgr,
734                                     const PreprocessorOptions &InitOpts) {
735   // Remap files in the source manager (with buffers).
736   for (PreprocessorOptions::const_remapped_file_buffer_iterator
737          Remap = InitOpts.remapped_file_buffer_begin(),
738          RemapEnd = InitOpts.remapped_file_buffer_end();
739        Remap != RemapEnd;
740        ++Remap) {
741     // Create the file entry for the file that we're mapping from.
742     const FileEntry *FromFile = FileMgr.getVirtualFile(Remap->first,
743                                                 Remap->second->getBufferSize(),
744                                                        0);
745     if (!FromFile) {
746       Diags.Report(diag::err_fe_remap_missing_from_file)
747         << Remap->first;
748       if (!InitOpts.RetainRemappedFileBuffers)
749         delete Remap->second;
750       continue;
751     }
752 
753     // Override the contents of the "from" file with the contents of
754     // the "to" file.
755     SourceMgr.overrideFileContents(FromFile, Remap->second,
756                                    InitOpts.RetainRemappedFileBuffers);
757   }
758 
759   // Remap files in the source manager (with other files).
760   for (PreprocessorOptions::const_remapped_file_iterator
761          Remap = InitOpts.remapped_file_begin(),
762          RemapEnd = InitOpts.remapped_file_end();
763        Remap != RemapEnd;
764        ++Remap) {
765     // Find the file that we're mapping to.
766     const FileEntry *ToFile = FileMgr.getFile(Remap->second);
767     if (!ToFile) {
768       Diags.Report(diag::err_fe_remap_missing_to_file)
769       << Remap->first << Remap->second;
770       continue;
771     }
772 
773     // Create the file entry for the file that we're mapping from.
774     const FileEntry *FromFile = FileMgr.getVirtualFile(Remap->first,
775                                                        ToFile->getSize(), 0);
776     if (!FromFile) {
777       Diags.Report(diag::err_fe_remap_missing_from_file)
778       << Remap->first;
779       continue;
780     }
781 
782     // Override the contents of the "from" file with the contents of
783     // the "to" file.
784     SourceMgr.overrideFileContents(FromFile, ToFile);
785   }
786 
787   SourceMgr.setOverridenFilesKeepOriginalName(
788                                         InitOpts.RemappedFilesKeepOriginalName);
789 }
790 
791 /// InitializePreprocessor - Initialize the preprocessor getting it and the
792 /// environment ready to process a single file. This returns true on error.
793 ///
794 void clang::InitializePreprocessor(Preprocessor &PP,
795                                    const PreprocessorOptions &InitOpts,
796                                    const HeaderSearchOptions &HSOpts,
797                                    const FrontendOptions &FEOpts) {
798   const LangOptions &LangOpts = PP.getLangOpts();
799   std::string PredefineBuffer;
800   PredefineBuffer.reserve(4080);
801   llvm::raw_string_ostream Predefines(PredefineBuffer);
802   MacroBuilder Builder(Predefines);
803 
804   InitializeFileRemapping(PP.getDiagnostics(), PP.getSourceManager(),
805                           PP.getFileManager(), InitOpts);
806 
807   // Emit line markers for various builtin sections of the file.  We don't do
808   // this in asm preprocessor mode, because "# 4" is not a line marker directive
809   // in this mode.
810   if (!PP.getLangOpts().AsmPreprocessor)
811     Builder.append("# 1 \"<built-in>\" 3");
812 
813   // Install things like __POWERPC__, __GNUC__, etc into the macro table.
814   if (InitOpts.UsePredefines) {
815     InitializePredefinedMacros(PP.getTargetInfo(), LangOpts, FEOpts, Builder);
816 
817     // Install definitions to make Objective-C++ ARC work well with various
818     // C++ Standard Library implementations.
819     if (LangOpts.ObjC1 && LangOpts.CPlusPlus && LangOpts.ObjCAutoRefCount) {
820       switch (InitOpts.ObjCXXARCStandardLibrary) {
821       case ARCXX_nolib:
822         case ARCXX_libcxx:
823         break;
824 
825       case ARCXX_libstdcxx:
826         AddObjCXXARCLibstdcxxDefines(LangOpts, Builder);
827         break;
828       }
829     }
830   }
831 
832   // Even with predefines off, some macros are still predefined.
833   // These should all be defined in the preprocessor according to the
834   // current language configuration.
835   InitializeStandardPredefinedMacros(PP.getTargetInfo(), PP.getLangOpts(),
836                                      FEOpts, Builder);
837 
838   // Add on the predefines from the driver.  Wrap in a #line directive to report
839   // that they come from the command line.
840   if (!PP.getLangOpts().AsmPreprocessor)
841     Builder.append("# 1 \"<command line>\" 1");
842 
843   // Process #define's and #undef's in the order they are given.
844   for (unsigned i = 0, e = InitOpts.Macros.size(); i != e; ++i) {
845     if (InitOpts.Macros[i].second)  // isUndef
846       Builder.undefineMacro(InitOpts.Macros[i].first);
847     else
848       DefineBuiltinMacro(Builder, InitOpts.Macros[i].first,
849                          PP.getDiagnostics());
850   }
851 
852   // If -imacros are specified, include them now.  These are processed before
853   // any -include directives.
854   for (unsigned i = 0, e = InitOpts.MacroIncludes.size(); i != e; ++i)
855     AddImplicitIncludeMacros(Builder, InitOpts.MacroIncludes[i],
856                              PP.getFileManager());
857 
858   // Process -include-pch/-include-pth directives.
859   if (!InitOpts.ImplicitPCHInclude.empty())
860     AddImplicitIncludePCH(Builder, PP, InitOpts.ImplicitPCHInclude);
861   if (!InitOpts.ImplicitPTHInclude.empty())
862     AddImplicitIncludePTH(Builder, PP, InitOpts.ImplicitPTHInclude);
863 
864   // Process -include directives.
865   for (unsigned i = 0, e = InitOpts.Includes.size(); i != e; ++i) {
866     const std::string &Path = InitOpts.Includes[i];
867     AddImplicitInclude(Builder, Path, PP.getFileManager());
868   }
869 
870   // Exit the command line and go back to <built-in> (2 is LC_LEAVE).
871   if (!PP.getLangOpts().AsmPreprocessor)
872     Builder.append("# 1 \"<built-in>\" 2");
873 
874   // Instruct the preprocessor to skip the preamble.
875   PP.setSkipMainFilePreamble(InitOpts.PrecompiledPreambleBytes.first,
876                              InitOpts.PrecompiledPreambleBytes.second);
877 
878   // Copy PredefinedBuffer into the Preprocessor.
879   PP.setPredefines(Predefines.str());
880 
881   // Initialize the header search object.
882   ApplyHeaderSearchOptions(PP.getHeaderSearchInfo(), HSOpts,
883                            PP.getLangOpts(),
884                            PP.getTargetInfo().getTriple());
885 }
886