xref: /llvm-project/clang/lib/Frontend/InitPreprocessor.cpp (revision 0c6f2f629cc0017361310fa4c132090413a874db)
1 //===--- InitPreprocessor.cpp - PP initialization code. ---------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file implements the clang::InitializePreprocessor function.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "clang/Basic/FileManager.h"
14 #include "clang/Basic/HLSLRuntime.h"
15 #include "clang/Basic/MacroBuilder.h"
16 #include "clang/Basic/SourceManager.h"
17 #include "clang/Basic/SyncScope.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/Frontend/Utils.h"
23 #include "clang/Lex/HeaderSearch.h"
24 #include "clang/Lex/Preprocessor.h"
25 #include "clang/Lex/PreprocessorOptions.h"
26 #include "clang/Serialization/ASTReader.h"
27 #include "llvm/ADT/APFloat.h"
28 #include "llvm/IR/DataLayout.h"
29 #include "llvm/IR/DerivedTypes.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 /// As these includes are generated by -include arguments the header search
69 /// logic is going to search relatively to the current working directory.
70 static void AddImplicitInclude(MacroBuilder &Builder, StringRef File) {
71   Builder.append(Twine("#include \"") + File + "\"");
72 }
73 
74 static void AddImplicitIncludeMacros(MacroBuilder &Builder, StringRef File) {
75   Builder.append(Twine("#__include_macros \"") + File + "\"");
76   // Marker token to stop the __include_macros fetch loop.
77   Builder.append("##"); // ##?
78 }
79 
80 /// Add an implicit \#include using the original file used to generate
81 /// a PCH file.
82 static void AddImplicitIncludePCH(MacroBuilder &Builder, Preprocessor &PP,
83                                   const PCHContainerReader &PCHContainerRdr,
84                                   StringRef ImplicitIncludePCH) {
85   std::string OriginalFile = ASTReader::getOriginalSourceFile(
86       std::string(ImplicitIncludePCH), PP.getFileManager(), PCHContainerRdr,
87       PP.getDiagnostics());
88   if (OriginalFile.empty())
89     return;
90 
91   AddImplicitInclude(Builder, OriginalFile);
92 }
93 
94 /// PickFP - This is used to pick a value based on the FP semantics of the
95 /// specified FP model.
96 template <typename T>
97 static T PickFP(const llvm::fltSemantics *Sem, T IEEEHalfVal, T IEEESingleVal,
98                 T IEEEDoubleVal, T X87DoubleExtendedVal, T PPCDoubleDoubleVal,
99                 T IEEEQuadVal) {
100   if (Sem == (const llvm::fltSemantics*)&llvm::APFloat::IEEEhalf())
101     return IEEEHalfVal;
102   if (Sem == (const llvm::fltSemantics*)&llvm::APFloat::IEEEsingle())
103     return IEEESingleVal;
104   if (Sem == (const llvm::fltSemantics*)&llvm::APFloat::IEEEdouble())
105     return IEEEDoubleVal;
106   if (Sem == (const llvm::fltSemantics*)&llvm::APFloat::x87DoubleExtended())
107     return X87DoubleExtendedVal;
108   if (Sem == (const llvm::fltSemantics*)&llvm::APFloat::PPCDoubleDouble())
109     return PPCDoubleDoubleVal;
110   assert(Sem == (const llvm::fltSemantics*)&llvm::APFloat::IEEEquad());
111   return IEEEQuadVal;
112 }
113 
114 static void DefineFloatMacros(MacroBuilder &Builder, StringRef Prefix,
115                               const llvm::fltSemantics *Sem, StringRef Ext) {
116   const char *DenormMin, *Epsilon, *Max, *Min;
117   DenormMin = PickFP(Sem, "5.9604644775390625e-8", "1.40129846e-45",
118                      "4.9406564584124654e-324", "3.64519953188247460253e-4951",
119                      "4.94065645841246544176568792868221e-324",
120                      "6.47517511943802511092443895822764655e-4966");
121   int Digits = PickFP(Sem, 3, 6, 15, 18, 31, 33);
122   int DecimalDigits = PickFP(Sem, 5, 9, 17, 21, 33, 36);
123   Epsilon = PickFP(Sem, "9.765625e-4", "1.19209290e-7",
124                    "2.2204460492503131e-16", "1.08420217248550443401e-19",
125                    "4.94065645841246544176568792868221e-324",
126                    "1.92592994438723585305597794258492732e-34");
127   int MantissaDigits = PickFP(Sem, 11, 24, 53, 64, 106, 113);
128   int Min10Exp = PickFP(Sem, -4, -37, -307, -4931, -291, -4931);
129   int Max10Exp = PickFP(Sem, 4, 38, 308, 4932, 308, 4932);
130   int MinExp = PickFP(Sem, -13, -125, -1021, -16381, -968, -16381);
131   int MaxExp = PickFP(Sem, 16, 128, 1024, 16384, 1024, 16384);
132   Min = PickFP(Sem, "6.103515625e-5", "1.17549435e-38", "2.2250738585072014e-308",
133                "3.36210314311209350626e-4932",
134                "2.00416836000897277799610805135016e-292",
135                "3.36210314311209350626267781732175260e-4932");
136   Max = PickFP(Sem, "6.5504e+4", "3.40282347e+38", "1.7976931348623157e+308",
137                "1.18973149535723176502e+4932",
138                "1.79769313486231580793728971405301e+308",
139                "1.18973149535723176508575932662800702e+4932");
140 
141   SmallString<32> DefPrefix;
142   DefPrefix = "__";
143   DefPrefix += Prefix;
144   DefPrefix += "_";
145 
146   Builder.defineMacro(DefPrefix + "DENORM_MIN__", Twine(DenormMin)+Ext);
147   Builder.defineMacro(DefPrefix + "HAS_DENORM__");
148   Builder.defineMacro(DefPrefix + "DIG__", Twine(Digits));
149   Builder.defineMacro(DefPrefix + "DECIMAL_DIG__", Twine(DecimalDigits));
150   Builder.defineMacro(DefPrefix + "EPSILON__", Twine(Epsilon)+Ext);
151   Builder.defineMacro(DefPrefix + "HAS_INFINITY__");
152   Builder.defineMacro(DefPrefix + "HAS_QUIET_NAN__");
153   Builder.defineMacro(DefPrefix + "MANT_DIG__", Twine(MantissaDigits));
154 
155   Builder.defineMacro(DefPrefix + "MAX_10_EXP__", Twine(Max10Exp));
156   Builder.defineMacro(DefPrefix + "MAX_EXP__", Twine(MaxExp));
157   Builder.defineMacro(DefPrefix + "MAX__", Twine(Max)+Ext);
158 
159   Builder.defineMacro(DefPrefix + "MIN_10_EXP__","("+Twine(Min10Exp)+")");
160   Builder.defineMacro(DefPrefix + "MIN_EXP__", "("+Twine(MinExp)+")");
161   Builder.defineMacro(DefPrefix + "MIN__", Twine(Min)+Ext);
162 }
163 
164 
165 /// DefineTypeSize - Emit a macro to the predefines buffer that declares a macro
166 /// named MacroName with the max value for a type with width 'TypeWidth' a
167 /// signedness of 'isSigned' and with a value suffix of 'ValSuffix' (e.g. LL).
168 static void DefineTypeSize(const Twine &MacroName, unsigned TypeWidth,
169                            StringRef ValSuffix, bool isSigned,
170                            MacroBuilder &Builder) {
171   llvm::APInt MaxVal = isSigned ? llvm::APInt::getSignedMaxValue(TypeWidth)
172                                 : llvm::APInt::getMaxValue(TypeWidth);
173   Builder.defineMacro(MacroName, toString(MaxVal, 10, isSigned) + ValSuffix);
174 }
175 
176 /// DefineTypeSize - An overloaded helper that uses TargetInfo to determine
177 /// the width, suffix, and signedness of the given type
178 static void DefineTypeSize(const Twine &MacroName, TargetInfo::IntType Ty,
179                            const TargetInfo &TI, MacroBuilder &Builder) {
180   DefineTypeSize(MacroName, TI.getTypeWidth(Ty), TI.getTypeConstantSuffix(Ty),
181                  TI.isTypeSigned(Ty), Builder);
182 }
183 
184 static void DefineFmt(const Twine &Prefix, TargetInfo::IntType Ty,
185                       const TargetInfo &TI, MacroBuilder &Builder) {
186   bool IsSigned = TI.isTypeSigned(Ty);
187   StringRef FmtModifier = TI.getTypeFormatModifier(Ty);
188   for (const char *Fmt = IsSigned ? "di" : "ouxX"; *Fmt; ++Fmt) {
189     Builder.defineMacro(Prefix + "_FMT" + Twine(*Fmt) + "__",
190                         Twine("\"") + FmtModifier + Twine(*Fmt) + "\"");
191   }
192 }
193 
194 static void DefineType(const Twine &MacroName, TargetInfo::IntType Ty,
195                        MacroBuilder &Builder) {
196   Builder.defineMacro(MacroName, TargetInfo::getTypeName(Ty));
197 }
198 
199 static void DefineTypeWidth(const Twine &MacroName, TargetInfo::IntType Ty,
200                             const TargetInfo &TI, MacroBuilder &Builder) {
201   Builder.defineMacro(MacroName, Twine(TI.getTypeWidth(Ty)));
202 }
203 
204 static void DefineTypeSizeof(StringRef MacroName, unsigned BitWidth,
205                              const TargetInfo &TI, MacroBuilder &Builder) {
206   Builder.defineMacro(MacroName,
207                       Twine(BitWidth / TI.getCharWidth()));
208 }
209 
210 // This will generate a macro based on the prefix with `_MAX__` as the suffix
211 // for the max value representable for the type, and a macro with a `_WIDTH__`
212 // suffix for the width of the type.
213 static void DefineTypeSizeAndWidth(const Twine &Prefix, TargetInfo::IntType Ty,
214                                    const TargetInfo &TI,
215                                    MacroBuilder &Builder) {
216   DefineTypeSize(Prefix + "_MAX__", Ty, TI, Builder);
217   DefineTypeWidth(Prefix + "_WIDTH__", Ty, TI, Builder);
218 }
219 
220 static void DefineExactWidthIntType(TargetInfo::IntType Ty,
221                                     const TargetInfo &TI,
222                                     MacroBuilder &Builder) {
223   int TypeWidth = TI.getTypeWidth(Ty);
224   bool IsSigned = TI.isTypeSigned(Ty);
225 
226   // Use the target specified int64 type, when appropriate, so that [u]int64_t
227   // ends up being defined in terms of the correct type.
228   if (TypeWidth == 64)
229     Ty = IsSigned ? TI.getInt64Type() : TI.getUInt64Type();
230 
231   // Use the target specified int16 type when appropriate. Some MCU targets
232   // (such as AVR) have definition of [u]int16_t to [un]signed int.
233   if (TypeWidth == 16)
234     Ty = IsSigned ? TI.getInt16Type() : TI.getUInt16Type();
235 
236   const char *Prefix = IsSigned ? "__INT" : "__UINT";
237 
238   DefineType(Prefix + Twine(TypeWidth) + "_TYPE__", Ty, Builder);
239   DefineFmt(Prefix + Twine(TypeWidth), Ty, TI, Builder);
240 
241   StringRef ConstSuffix(TI.getTypeConstantSuffix(Ty));
242   Builder.defineMacro(Prefix + Twine(TypeWidth) + "_C_SUFFIX__", ConstSuffix);
243 }
244 
245 static void DefineExactWidthIntTypeSize(TargetInfo::IntType Ty,
246                                         const TargetInfo &TI,
247                                         MacroBuilder &Builder) {
248   int TypeWidth = TI.getTypeWidth(Ty);
249   bool IsSigned = TI.isTypeSigned(Ty);
250 
251   // Use the target specified int64 type, when appropriate, so that [u]int64_t
252   // ends up being defined in terms of the correct type.
253   if (TypeWidth == 64)
254     Ty = IsSigned ? TI.getInt64Type() : TI.getUInt64Type();
255 
256   // We don't need to define a _WIDTH macro for the exact-width types because
257   // we already know the width.
258   const char *Prefix = IsSigned ? "__INT" : "__UINT";
259   DefineTypeSize(Prefix + Twine(TypeWidth) + "_MAX__", Ty, TI, Builder);
260 }
261 
262 static void DefineLeastWidthIntType(unsigned TypeWidth, bool IsSigned,
263                                     const TargetInfo &TI,
264                                     MacroBuilder &Builder) {
265   TargetInfo::IntType Ty = TI.getLeastIntTypeByWidth(TypeWidth, IsSigned);
266   if (Ty == TargetInfo::NoInt)
267     return;
268 
269   const char *Prefix = IsSigned ? "__INT_LEAST" : "__UINT_LEAST";
270   DefineType(Prefix + Twine(TypeWidth) + "_TYPE__", Ty, Builder);
271   // We only want the *_WIDTH macro for the signed types to avoid too many
272   // predefined macros (the unsigned width and the signed width are identical.)
273   if (IsSigned)
274     DefineTypeSizeAndWidth(Prefix + Twine(TypeWidth), Ty, TI, Builder);
275   else
276     DefineTypeSize(Prefix + Twine(TypeWidth) + "_MAX__", Ty, TI, Builder);
277   DefineFmt(Prefix + Twine(TypeWidth), Ty, TI, Builder);
278 }
279 
280 static void DefineFastIntType(unsigned TypeWidth, bool IsSigned,
281                               const TargetInfo &TI, MacroBuilder &Builder) {
282   // stdint.h currently defines the fast int types as equivalent to the least
283   // types.
284   TargetInfo::IntType Ty = TI.getLeastIntTypeByWidth(TypeWidth, IsSigned);
285   if (Ty == TargetInfo::NoInt)
286     return;
287 
288   const char *Prefix = IsSigned ? "__INT_FAST" : "__UINT_FAST";
289   DefineType(Prefix + Twine(TypeWidth) + "_TYPE__", Ty, Builder);
290   // We only want the *_WIDTH macro for the signed types to avoid too many
291   // predefined macros (the unsigned width and the signed width are identical.)
292   if (IsSigned)
293     DefineTypeSizeAndWidth(Prefix + Twine(TypeWidth), Ty, TI, Builder);
294   else
295     DefineTypeSize(Prefix + Twine(TypeWidth) + "_MAX__", Ty, TI, Builder);
296   DefineFmt(Prefix + Twine(TypeWidth), Ty, TI, Builder);
297 }
298 
299 
300 /// Get the value the ATOMIC_*_LOCK_FREE macro should have for a type with
301 /// the specified properties.
302 static const char *getLockFreeValue(unsigned TypeWidth, const TargetInfo &TI) {
303   // Fully-aligned, power-of-2 sizes no larger than the inline
304   // width will be inlined as lock-free operations.
305   // Note: we do not need to check alignment since _Atomic(T) is always
306   // appropriately-aligned in clang.
307   if (TI.hasBuiltinAtomic(TypeWidth, TypeWidth))
308     return "2"; // "always lock free"
309   // We cannot be certain what operations the lib calls might be
310   // able to implement as lock-free on future processors.
311   return "1"; // "sometimes lock free"
312 }
313 
314 /// Add definitions required for a smooth interaction between
315 /// Objective-C++ automated reference counting and libstdc++ (4.2).
316 static void AddObjCXXARCLibstdcxxDefines(const LangOptions &LangOpts,
317                                          MacroBuilder &Builder) {
318   Builder.defineMacro("_GLIBCXX_PREDEFINED_OBJC_ARC_IS_SCALAR");
319 
320   std::string Result;
321   {
322     // Provide specializations for the __is_scalar type trait so that
323     // lifetime-qualified objects are not considered "scalar" types, which
324     // libstdc++ uses as an indicator of the presence of trivial copy, assign,
325     // default-construct, and destruct semantics (none of which hold for
326     // lifetime-qualified objects in ARC).
327     llvm::raw_string_ostream Out(Result);
328 
329     Out << "namespace std {\n"
330         << "\n"
331         << "struct __true_type;\n"
332         << "struct __false_type;\n"
333         << "\n";
334 
335     Out << "template<typename _Tp> struct __is_scalar;\n"
336         << "\n";
337 
338     if (LangOpts.ObjCAutoRefCount) {
339       Out << "template<typename _Tp>\n"
340           << "struct __is_scalar<__attribute__((objc_ownership(strong))) _Tp> {\n"
341           << "  enum { __value = 0 };\n"
342           << "  typedef __false_type __type;\n"
343           << "};\n"
344           << "\n";
345     }
346 
347     if (LangOpts.ObjCWeak) {
348       Out << "template<typename _Tp>\n"
349           << "struct __is_scalar<__attribute__((objc_ownership(weak))) _Tp> {\n"
350           << "  enum { __value = 0 };\n"
351           << "  typedef __false_type __type;\n"
352           << "};\n"
353           << "\n";
354     }
355 
356     if (LangOpts.ObjCAutoRefCount) {
357       Out << "template<typename _Tp>\n"
358           << "struct __is_scalar<__attribute__((objc_ownership(autoreleasing)))"
359           << " _Tp> {\n"
360           << "  enum { __value = 0 };\n"
361           << "  typedef __false_type __type;\n"
362           << "};\n"
363           << "\n";
364     }
365 
366     Out << "}\n";
367   }
368   Builder.append(Result);
369 }
370 
371 static void InitializeStandardPredefinedMacros(const TargetInfo &TI,
372                                                const LangOptions &LangOpts,
373                                                const FrontendOptions &FEOpts,
374                                                MacroBuilder &Builder) {
375   if (LangOpts.HLSL) {
376     Builder.defineMacro("__hlsl_clang");
377     // HLSL Version
378     Builder.defineMacro("__HLSL_VERSION",
379                         Twine((unsigned)LangOpts.getHLSLVersion()));
380 
381     if (LangOpts.NativeHalfType)
382       Builder.defineMacro("__HLSL_ENABLE_16_BIT",
383                           Twine((unsigned)LangOpts.getHLSLVersion()));
384 
385     // Shader target information
386     // "enums" for shader stages
387     Builder.defineMacro("__SHADER_STAGE_VERTEX",
388                         Twine((uint32_t)ShaderStage::Vertex));
389     Builder.defineMacro("__SHADER_STAGE_PIXEL",
390                         Twine((uint32_t)ShaderStage::Pixel));
391     Builder.defineMacro("__SHADER_STAGE_GEOMETRY",
392                         Twine((uint32_t)ShaderStage::Geometry));
393     Builder.defineMacro("__SHADER_STAGE_HULL",
394                         Twine((uint32_t)ShaderStage::Hull));
395     Builder.defineMacro("__SHADER_STAGE_DOMAIN",
396                         Twine((uint32_t)ShaderStage::Domain));
397     Builder.defineMacro("__SHADER_STAGE_COMPUTE",
398                         Twine((uint32_t)ShaderStage::Compute));
399     Builder.defineMacro("__SHADER_STAGE_AMPLIFICATION",
400                         Twine((uint32_t)ShaderStage::Amplification));
401     Builder.defineMacro("__SHADER_STAGE_MESH",
402                         Twine((uint32_t)ShaderStage::Mesh));
403     Builder.defineMacro("__SHADER_STAGE_LIBRARY",
404                         Twine((uint32_t)ShaderStage::Library));
405     // The current shader stage itself
406     uint32_t StageInteger = static_cast<uint32_t>(
407         hlsl::getStageFromEnvironment(TI.getTriple().getEnvironment()));
408 
409     Builder.defineMacro("__SHADER_TARGET_STAGE", Twine(StageInteger));
410     // Add target versions
411     if (TI.getTriple().getOS() == llvm::Triple::ShaderModel) {
412       VersionTuple Version = TI.getTriple().getOSVersion();
413       Builder.defineMacro("__SHADER_TARGET_MAJOR", Twine(Version.getMajor()));
414       unsigned Minor = Version.getMinor().value_or(0);
415       Builder.defineMacro("__SHADER_TARGET_MINOR", Twine(Minor));
416     }
417     return;
418   }
419   // C++ [cpp.predefined]p1:
420   //   The following macro names shall be defined by the implementation:
421 
422   //   -- __STDC__
423   //      [C++] Whether __STDC__ is predefined and if so, what its value is,
424   //      are implementation-defined.
425   // (Removed in C++20.)
426   if (!LangOpts.MSVCCompat && !LangOpts.TraditionalCPP)
427     Builder.defineMacro("__STDC__");
428   //   -- __STDC_HOSTED__
429   //      The integer literal 1 if the implementation is a hosted
430   //      implementation or the integer literal 0 if it is not.
431   if (LangOpts.Freestanding)
432     Builder.defineMacro("__STDC_HOSTED__", "0");
433   else
434     Builder.defineMacro("__STDC_HOSTED__");
435 
436   //   -- __STDC_VERSION__
437   //      [C++] Whether __STDC_VERSION__ is predefined and if so, what its
438   //      value is, are implementation-defined.
439   // (Removed in C++20.)
440   if (!LangOpts.CPlusPlus) {
441     // FIXME: Use correct value for C23.
442     if (LangOpts.C2x)
443       Builder.defineMacro("__STDC_VERSION__", "202000L");
444     else if (LangOpts.C17)
445       Builder.defineMacro("__STDC_VERSION__", "201710L");
446     else if (LangOpts.C11)
447       Builder.defineMacro("__STDC_VERSION__", "201112L");
448     else if (LangOpts.C99)
449       Builder.defineMacro("__STDC_VERSION__", "199901L");
450     else if (!LangOpts.GNUMode && LangOpts.Digraphs)
451       Builder.defineMacro("__STDC_VERSION__", "199409L");
452   } else {
453     //   -- __cplusplus
454     if (LangOpts.CPlusPlus26)
455       // FIXME: Use correct value for C++26.
456       Builder.defineMacro("__cplusplus", "202400L");
457     else if (LangOpts.CPlusPlus23)
458       Builder.defineMacro("__cplusplus", "202302L");
459     //      [C++20] The integer literal 202002L.
460     else if (LangOpts.CPlusPlus20)
461       Builder.defineMacro("__cplusplus", "202002L");
462     //      [C++17] The integer literal 201703L.
463     else if (LangOpts.CPlusPlus17)
464       Builder.defineMacro("__cplusplus", "201703L");
465     //      [C++14] The name __cplusplus is defined to the value 201402L when
466     //      compiling a C++ translation unit.
467     else if (LangOpts.CPlusPlus14)
468       Builder.defineMacro("__cplusplus", "201402L");
469     //      [C++11] The name __cplusplus is defined to the value 201103L when
470     //      compiling a C++ translation unit.
471     else if (LangOpts.CPlusPlus11)
472       Builder.defineMacro("__cplusplus", "201103L");
473     //      [C++03] The name __cplusplus is defined to the value 199711L when
474     //      compiling a C++ translation unit.
475     else
476       Builder.defineMacro("__cplusplus", "199711L");
477 
478     //   -- __STDCPP_DEFAULT_NEW_ALIGNMENT__
479     //      [C++17] An integer literal of type std::size_t whose value is the
480     //      alignment guaranteed by a call to operator new(std::size_t)
481     //
482     // We provide this in all language modes, since it seems generally useful.
483     Builder.defineMacro("__STDCPP_DEFAULT_NEW_ALIGNMENT__",
484                         Twine(TI.getNewAlign() / TI.getCharWidth()) +
485                             TI.getTypeConstantSuffix(TI.getSizeType()));
486 
487     //   -- __STDCPP_­THREADS__
488     //      Defined, and has the value integer literal 1, if and only if a
489     //      program can have more than one thread of execution.
490     if (LangOpts.getThreadModel() == LangOptions::ThreadModelKind::POSIX)
491       Builder.defineMacro("__STDCPP_THREADS__", "1");
492   }
493 
494   // In C11 these are environment macros. In C++11 they are only defined
495   // as part of <cuchar>. To prevent breakage when mixing C and C++
496   // code, define these macros unconditionally. We can define them
497   // unconditionally, as Clang always uses UTF-16 and UTF-32 for 16-bit
498   // and 32-bit character literals.
499   Builder.defineMacro("__STDC_UTF_16__", "1");
500   Builder.defineMacro("__STDC_UTF_32__", "1");
501 
502   if (LangOpts.ObjC)
503     Builder.defineMacro("__OBJC__");
504 
505   // OpenCL v1.0/1.1 s6.9, v1.2/2.0 s6.10: Preprocessor Directives and Macros.
506   if (LangOpts.OpenCL) {
507     if (LangOpts.CPlusPlus) {
508       switch (LangOpts.OpenCLCPlusPlusVersion) {
509       case 100:
510         Builder.defineMacro("__OPENCL_CPP_VERSION__", "100");
511         break;
512       case 202100:
513         Builder.defineMacro("__OPENCL_CPP_VERSION__", "202100");
514         break;
515       default:
516         llvm_unreachable("Unsupported C++ version for OpenCL");
517       }
518       Builder.defineMacro("__CL_CPP_VERSION_1_0__", "100");
519       Builder.defineMacro("__CL_CPP_VERSION_2021__", "202100");
520     } else {
521       // OpenCL v1.0 and v1.1 do not have a predefined macro to indicate the
522       // language standard with which the program is compiled. __OPENCL_VERSION__
523       // is for the OpenCL version supported by the OpenCL device, which is not
524       // necessarily the language standard with which the program is compiled.
525       // A shared OpenCL header file requires a macro to indicate the language
526       // standard. As a workaround, __OPENCL_C_VERSION__ is defined for
527       // OpenCL v1.0 and v1.1.
528       switch (LangOpts.OpenCLVersion) {
529       case 100:
530         Builder.defineMacro("__OPENCL_C_VERSION__", "100");
531         break;
532       case 110:
533         Builder.defineMacro("__OPENCL_C_VERSION__", "110");
534         break;
535       case 120:
536         Builder.defineMacro("__OPENCL_C_VERSION__", "120");
537         break;
538       case 200:
539         Builder.defineMacro("__OPENCL_C_VERSION__", "200");
540         break;
541       case 300:
542         Builder.defineMacro("__OPENCL_C_VERSION__", "300");
543         break;
544       default:
545         llvm_unreachable("Unsupported OpenCL version");
546       }
547     }
548     Builder.defineMacro("CL_VERSION_1_0", "100");
549     Builder.defineMacro("CL_VERSION_1_1", "110");
550     Builder.defineMacro("CL_VERSION_1_2", "120");
551     Builder.defineMacro("CL_VERSION_2_0", "200");
552     Builder.defineMacro("CL_VERSION_3_0", "300");
553 
554     if (TI.isLittleEndian())
555       Builder.defineMacro("__ENDIAN_LITTLE__");
556 
557     if (LangOpts.FastRelaxedMath)
558       Builder.defineMacro("__FAST_RELAXED_MATH__");
559   }
560 
561   if (LangOpts.SYCLIsDevice || LangOpts.SYCLIsHost) {
562     // SYCL Version is set to a value when building SYCL applications
563     if (LangOpts.getSYCLVersion() == LangOptions::SYCL_2017)
564       Builder.defineMacro("CL_SYCL_LANGUAGE_VERSION", "121");
565     else if (LangOpts.getSYCLVersion() == LangOptions::SYCL_2020)
566       Builder.defineMacro("SYCL_LANGUAGE_VERSION", "202001");
567   }
568 
569   // Not "standard" per se, but available even with the -undef flag.
570   if (LangOpts.AsmPreprocessor)
571     Builder.defineMacro("__ASSEMBLER__");
572   if (LangOpts.CUDA) {
573     if (LangOpts.GPURelocatableDeviceCode)
574       Builder.defineMacro("__CLANG_RDC__");
575     if (!LangOpts.HIP)
576       Builder.defineMacro("__CUDA__");
577   }
578   if (LangOpts.HIP) {
579     Builder.defineMacro("__HIP__");
580     Builder.defineMacro("__HIPCC__");
581     Builder.defineMacro("__HIP_MEMORY_SCOPE_SINGLETHREAD", "1");
582     Builder.defineMacro("__HIP_MEMORY_SCOPE_WAVEFRONT", "2");
583     Builder.defineMacro("__HIP_MEMORY_SCOPE_WORKGROUP", "3");
584     Builder.defineMacro("__HIP_MEMORY_SCOPE_AGENT", "4");
585     Builder.defineMacro("__HIP_MEMORY_SCOPE_SYSTEM", "5");
586     if (LangOpts.CUDAIsDevice) {
587       Builder.defineMacro("__HIP_DEVICE_COMPILE__");
588       if (!TI.hasHIPImageSupport())
589         Builder.defineMacro("__HIP_NO_IMAGE_SUPPORT", "1");
590     }
591     if (LangOpts.GPUDefaultStream ==
592         LangOptions::GPUDefaultStreamKind::PerThread)
593       Builder.defineMacro("HIP_API_PER_THREAD_DEFAULT_STREAM");
594   }
595 }
596 
597 /// Initialize the predefined C++ language feature test macros defined in
598 /// ISO/IEC JTC1/SC22/WG21 (C++) SD-6: "SG10 Feature Test Recommendations".
599 static void InitializeCPlusPlusFeatureTestMacros(const LangOptions &LangOpts,
600                                                  MacroBuilder &Builder) {
601   // C++98 features.
602   if (LangOpts.RTTI)
603     Builder.defineMacro("__cpp_rtti", "199711L");
604   if (LangOpts.CXXExceptions)
605     Builder.defineMacro("__cpp_exceptions", "199711L");
606 
607   // C++11 features.
608   if (LangOpts.CPlusPlus11) {
609     Builder.defineMacro("__cpp_unicode_characters", "200704L");
610     Builder.defineMacro("__cpp_raw_strings", "200710L");
611     Builder.defineMacro("__cpp_unicode_literals", "200710L");
612     Builder.defineMacro("__cpp_user_defined_literals", "200809L");
613     Builder.defineMacro("__cpp_lambdas", "200907L");
614     Builder.defineMacro("__cpp_constexpr", LangOpts.CPlusPlus23   ? "202211L"
615                                            : LangOpts.CPlusPlus20 ? "201907L"
616                                            : LangOpts.CPlusPlus17 ? "201603L"
617                                            : LangOpts.CPlusPlus14 ? "201304L"
618                                                                   : "200704");
619     Builder.defineMacro("__cpp_constexpr_in_decltype", "201711L");
620     Builder.defineMacro("__cpp_range_based_for",
621                         LangOpts.CPlusPlus17 ? "201603L" : "200907");
622     Builder.defineMacro("__cpp_static_assert",
623                         LangOpts.CPlusPlus17 ? "201411L" : "200410");
624     Builder.defineMacro("__cpp_decltype", "200707L");
625     Builder.defineMacro("__cpp_attributes", "200809L");
626     Builder.defineMacro("__cpp_rvalue_references", "200610L");
627     Builder.defineMacro("__cpp_variadic_templates", "200704L");
628     Builder.defineMacro("__cpp_initializer_lists", "200806L");
629     Builder.defineMacro("__cpp_delegating_constructors", "200604L");
630     Builder.defineMacro("__cpp_nsdmi", "200809L");
631     Builder.defineMacro("__cpp_inheriting_constructors", "201511L");
632     Builder.defineMacro("__cpp_ref_qualifiers", "200710L");
633     Builder.defineMacro("__cpp_alias_templates", "200704L");
634   }
635   if (LangOpts.ThreadsafeStatics)
636     Builder.defineMacro("__cpp_threadsafe_static_init", "200806L");
637 
638   // C++14 features.
639   if (LangOpts.CPlusPlus14) {
640     Builder.defineMacro("__cpp_binary_literals", "201304L");
641     Builder.defineMacro("__cpp_digit_separators", "201309L");
642     Builder.defineMacro("__cpp_init_captures",
643                         LangOpts.CPlusPlus20 ? "201803L" : "201304L");
644     Builder.defineMacro("__cpp_generic_lambdas",
645                         LangOpts.CPlusPlus20 ? "201707L" : "201304L");
646     Builder.defineMacro("__cpp_decltype_auto", "201304L");
647     Builder.defineMacro("__cpp_return_type_deduction", "201304L");
648     Builder.defineMacro("__cpp_aggregate_nsdmi", "201304L");
649     Builder.defineMacro("__cpp_variable_templates", "201304L");
650   }
651   if (LangOpts.SizedDeallocation)
652     Builder.defineMacro("__cpp_sized_deallocation", "201309L");
653 
654   // C++17 features.
655   if (LangOpts.CPlusPlus17) {
656     Builder.defineMacro("__cpp_hex_float", "201603L");
657     Builder.defineMacro("__cpp_inline_variables", "201606L");
658     Builder.defineMacro("__cpp_noexcept_function_type", "201510L");
659     Builder.defineMacro("__cpp_capture_star_this", "201603L");
660     Builder.defineMacro("__cpp_if_constexpr", "201606L");
661     Builder.defineMacro("__cpp_deduction_guides", "201703L"); // (not latest)
662     Builder.defineMacro("__cpp_template_auto", "201606L"); // (old name)
663     Builder.defineMacro("__cpp_namespace_attributes", "201411L");
664     Builder.defineMacro("__cpp_enumerator_attributes", "201411L");
665     Builder.defineMacro("__cpp_nested_namespace_definitions", "201411L");
666     Builder.defineMacro("__cpp_variadic_using", "201611L");
667     Builder.defineMacro("__cpp_aggregate_bases", "201603L");
668     Builder.defineMacro("__cpp_structured_bindings", "201606L");
669     Builder.defineMacro("__cpp_nontype_template_args",
670                         "201411L"); // (not latest)
671     Builder.defineMacro("__cpp_fold_expressions", "201603L");
672     Builder.defineMacro("__cpp_guaranteed_copy_elision", "201606L");
673     Builder.defineMacro("__cpp_nontype_template_parameter_auto", "201606L");
674   }
675   if (LangOpts.AlignedAllocation && !LangOpts.AlignedAllocationUnavailable)
676     Builder.defineMacro("__cpp_aligned_new", "201606L");
677   if (LangOpts.RelaxedTemplateTemplateArgs)
678     Builder.defineMacro("__cpp_template_template_args", "201611L");
679 
680   // C++20 features.
681   if (LangOpts.CPlusPlus20) {
682     Builder.defineMacro("__cpp_aggregate_paren_init", "201902L");
683 
684     // P0848 is implemented, but we're still waiting for other concepts
685     // issues to be addressed before bumping __cpp_concepts up to 202002L.
686     // Refer to the discussion of this at https://reviews.llvm.org/D128619.
687     Builder.defineMacro("__cpp_concepts", "201907L");
688     Builder.defineMacro("__cpp_conditional_explicit", "201806L");
689     Builder.defineMacro("__cpp_consteval", "202211L");
690     Builder.defineMacro("__cpp_constexpr_dynamic_alloc", "201907L");
691     Builder.defineMacro("__cpp_constinit", "201907L");
692     Builder.defineMacro("__cpp_impl_coroutine", "201902L");
693     Builder.defineMacro("__cpp_designated_initializers", "201707L");
694     Builder.defineMacro("__cpp_impl_three_way_comparison", "201907L");
695     //Builder.defineMacro("__cpp_modules", "201907L");
696     Builder.defineMacro("__cpp_using_enum", "201907L");
697   }
698   // C++23 features.
699   if (LangOpts.CPlusPlus23) {
700     Builder.defineMacro("__cpp_implicit_move", "202011L");
701     Builder.defineMacro("__cpp_size_t_suffix", "202011L");
702     Builder.defineMacro("__cpp_if_consteval", "202106L");
703     Builder.defineMacro("__cpp_multidimensional_subscript", "202211L");
704   }
705 
706   // We provide those C++23 features as extensions in earlier language modes, so
707   // we also define their feature test macros.
708   if (LangOpts.CPlusPlus11)
709     Builder.defineMacro("__cpp_static_call_operator", "202207L");
710   Builder.defineMacro("__cpp_named_character_escapes", "202207L");
711 
712   if (LangOpts.Char8)
713     Builder.defineMacro("__cpp_char8_t", "202207L");
714   Builder.defineMacro("__cpp_impl_destroying_delete", "201806L");
715 }
716 
717 /// InitializeOpenCLFeatureTestMacros - Define OpenCL macros based on target
718 /// settings and language version
719 void InitializeOpenCLFeatureTestMacros(const TargetInfo &TI,
720                                        const LangOptions &Opts,
721                                        MacroBuilder &Builder) {
722   const llvm::StringMap<bool> &OpenCLFeaturesMap = TI.getSupportedOpenCLOpts();
723   // FIXME: OpenCL options which affect language semantics/syntax
724   // should be moved into LangOptions.
725   auto defineOpenCLExtMacro = [&](llvm::StringRef Name, auto... OptArgs) {
726     // Check if extension is supported by target and is available in this
727     // OpenCL version
728     if (TI.hasFeatureEnabled(OpenCLFeaturesMap, Name) &&
729         OpenCLOptions::isOpenCLOptionAvailableIn(Opts, OptArgs...))
730       Builder.defineMacro(Name);
731   };
732 #define OPENCL_GENERIC_EXTENSION(Ext, ...)                                     \
733   defineOpenCLExtMacro(#Ext, __VA_ARGS__);
734 #include "clang/Basic/OpenCLExtensions.def"
735 
736   // Assume compiling for FULL profile
737   Builder.defineMacro("__opencl_c_int64");
738 }
739 
740 static void InitializePredefinedMacros(const TargetInfo &TI,
741                                        const LangOptions &LangOpts,
742                                        const FrontendOptions &FEOpts,
743                                        const PreprocessorOptions &PPOpts,
744                                        MacroBuilder &Builder) {
745   // Compiler version introspection macros.
746   Builder.defineMacro("__llvm__");  // LLVM Backend
747   Builder.defineMacro("__clang__"); // Clang Frontend
748 #define TOSTR2(X) #X
749 #define TOSTR(X) TOSTR2(X)
750   Builder.defineMacro("__clang_major__", TOSTR(CLANG_VERSION_MAJOR));
751   Builder.defineMacro("__clang_minor__", TOSTR(CLANG_VERSION_MINOR));
752   Builder.defineMacro("__clang_patchlevel__", TOSTR(CLANG_VERSION_PATCHLEVEL));
753 #undef TOSTR
754 #undef TOSTR2
755   Builder.defineMacro("__clang_version__",
756                       "\"" CLANG_VERSION_STRING " "
757                       + getClangFullRepositoryVersion() + "\"");
758 
759   if (LangOpts.GNUCVersion != 0) {
760     // Major, minor, patch, are given two decimal places each, so 4.2.1 becomes
761     // 40201.
762     unsigned GNUCMajor = LangOpts.GNUCVersion / 100 / 100;
763     unsigned GNUCMinor = LangOpts.GNUCVersion / 100 % 100;
764     unsigned GNUCPatch = LangOpts.GNUCVersion % 100;
765     Builder.defineMacro("__GNUC__", Twine(GNUCMajor));
766     Builder.defineMacro("__GNUC_MINOR__", Twine(GNUCMinor));
767     Builder.defineMacro("__GNUC_PATCHLEVEL__", Twine(GNUCPatch));
768     Builder.defineMacro("__GXX_ABI_VERSION", "1002");
769 
770     if (LangOpts.CPlusPlus) {
771       Builder.defineMacro("__GNUG__", Twine(GNUCMajor));
772       Builder.defineMacro("__GXX_WEAK__");
773     }
774   }
775 
776   // Define macros for the C11 / C++11 memory orderings
777   Builder.defineMacro("__ATOMIC_RELAXED", "0");
778   Builder.defineMacro("__ATOMIC_CONSUME", "1");
779   Builder.defineMacro("__ATOMIC_ACQUIRE", "2");
780   Builder.defineMacro("__ATOMIC_RELEASE", "3");
781   Builder.defineMacro("__ATOMIC_ACQ_REL", "4");
782   Builder.defineMacro("__ATOMIC_SEQ_CST", "5");
783 
784   // Define macros for the OpenCL memory scope.
785   // The values should match AtomicScopeOpenCLModel::ID enum.
786   static_assert(
787       static_cast<unsigned>(AtomicScopeOpenCLModel::WorkGroup) == 1 &&
788           static_cast<unsigned>(AtomicScopeOpenCLModel::Device) == 2 &&
789           static_cast<unsigned>(AtomicScopeOpenCLModel::AllSVMDevices) == 3 &&
790           static_cast<unsigned>(AtomicScopeOpenCLModel::SubGroup) == 4,
791       "Invalid OpenCL memory scope enum definition");
792   Builder.defineMacro("__OPENCL_MEMORY_SCOPE_WORK_ITEM", "0");
793   Builder.defineMacro("__OPENCL_MEMORY_SCOPE_WORK_GROUP", "1");
794   Builder.defineMacro("__OPENCL_MEMORY_SCOPE_DEVICE", "2");
795   Builder.defineMacro("__OPENCL_MEMORY_SCOPE_ALL_SVM_DEVICES", "3");
796   Builder.defineMacro("__OPENCL_MEMORY_SCOPE_SUB_GROUP", "4");
797 
798   // Support for #pragma redefine_extname (Sun compatibility)
799   Builder.defineMacro("__PRAGMA_REDEFINE_EXTNAME", "1");
800 
801   // Previously this macro was set to a string aiming to achieve compatibility
802   // with GCC 4.2.1. Now, just return the full Clang version
803   Builder.defineMacro("__VERSION__", "\"" +
804                       Twine(getClangFullCPPVersion()) + "\"");
805 
806   // Initialize language-specific preprocessor defines.
807 
808   // Standard conforming mode?
809   if (!LangOpts.GNUMode && !LangOpts.MSVCCompat)
810     Builder.defineMacro("__STRICT_ANSI__");
811 
812   if (LangOpts.GNUCVersion && LangOpts.CPlusPlus11)
813     Builder.defineMacro("__GXX_EXPERIMENTAL_CXX0X__");
814 
815   if (LangOpts.ObjC) {
816     if (LangOpts.ObjCRuntime.isNonFragile()) {
817       Builder.defineMacro("__OBJC2__");
818 
819       if (LangOpts.ObjCExceptions)
820         Builder.defineMacro("OBJC_ZEROCOST_EXCEPTIONS");
821     }
822 
823     if (LangOpts.getGC() != LangOptions::NonGC)
824       Builder.defineMacro("__OBJC_GC__");
825 
826     if (LangOpts.ObjCRuntime.isNeXTFamily())
827       Builder.defineMacro("__NEXT_RUNTIME__");
828 
829     if (LangOpts.ObjCRuntime.getKind() == ObjCRuntime::GNUstep) {
830       auto version = LangOpts.ObjCRuntime.getVersion();
831       std::string versionString = "1";
832       // Don't rely on the tuple argument, because we can be asked to target
833       // later ABIs than we actually support, so clamp these values to those
834       // currently supported
835       if (version >= VersionTuple(2, 0))
836         Builder.defineMacro("__OBJC_GNUSTEP_RUNTIME_ABI__", "20");
837       else
838         Builder.defineMacro(
839             "__OBJC_GNUSTEP_RUNTIME_ABI__",
840             "1" + Twine(std::min(8U, version.getMinor().value_or(0))));
841     }
842 
843     if (LangOpts.ObjCRuntime.getKind() == ObjCRuntime::ObjFW) {
844       VersionTuple tuple = LangOpts.ObjCRuntime.getVersion();
845       unsigned minor = tuple.getMinor().value_or(0);
846       unsigned subminor = tuple.getSubminor().value_or(0);
847       Builder.defineMacro("__OBJFW_RUNTIME_ABI__",
848                           Twine(tuple.getMajor() * 10000 + minor * 100 +
849                                 subminor));
850     }
851 
852     Builder.defineMacro("IBOutlet", "__attribute__((iboutlet))");
853     Builder.defineMacro("IBOutletCollection(ClassName)",
854                         "__attribute__((iboutletcollection(ClassName)))");
855     Builder.defineMacro("IBAction", "void)__attribute__((ibaction)");
856     Builder.defineMacro("IBInspectable", "");
857     Builder.defineMacro("IB_DESIGNABLE", "");
858   }
859 
860   // Define a macro that describes the Objective-C boolean type even for C
861   // and C++ since BOOL can be used from non Objective-C code.
862   Builder.defineMacro("__OBJC_BOOL_IS_BOOL",
863                       Twine(TI.useSignedCharForObjCBool() ? "0" : "1"));
864 
865   if (LangOpts.CPlusPlus)
866     InitializeCPlusPlusFeatureTestMacros(LangOpts, Builder);
867 
868   // darwin_constant_cfstrings controls this. This is also dependent
869   // on other things like the runtime I believe.  This is set even for C code.
870   if (!LangOpts.NoConstantCFStrings)
871       Builder.defineMacro("__CONSTANT_CFSTRINGS__");
872 
873   if (LangOpts.ObjC)
874     Builder.defineMacro("OBJC_NEW_PROPERTIES");
875 
876   if (LangOpts.PascalStrings)
877     Builder.defineMacro("__PASCAL_STRINGS__");
878 
879   if (LangOpts.Blocks) {
880     Builder.defineMacro("__block", "__attribute__((__blocks__(byref)))");
881     Builder.defineMacro("__BLOCKS__");
882   }
883 
884   if (!LangOpts.MSVCCompat && LangOpts.Exceptions)
885     Builder.defineMacro("__EXCEPTIONS");
886   if (LangOpts.GNUCVersion && LangOpts.RTTI)
887     Builder.defineMacro("__GXX_RTTI");
888 
889   if (LangOpts.hasSjLjExceptions())
890     Builder.defineMacro("__USING_SJLJ_EXCEPTIONS__");
891   else if (LangOpts.hasSEHExceptions())
892     Builder.defineMacro("__SEH__");
893   else if (LangOpts.hasDWARFExceptions() &&
894            (TI.getTriple().isThumb() || TI.getTriple().isARM()))
895     Builder.defineMacro("__ARM_DWARF_EH__");
896 
897   if (LangOpts.Deprecated)
898     Builder.defineMacro("__DEPRECATED");
899 
900   if (!LangOpts.MSVCCompat && LangOpts.CPlusPlus)
901     Builder.defineMacro("__private_extern__", "extern");
902 
903   if (LangOpts.MicrosoftExt) {
904     if (LangOpts.WChar) {
905       // wchar_t supported as a keyword.
906       Builder.defineMacro("_WCHAR_T_DEFINED");
907       Builder.defineMacro("_NATIVE_WCHAR_T_DEFINED");
908     }
909   }
910 
911   // Macros to help identify the narrow and wide character sets
912   // FIXME: clang currently ignores -fexec-charset=. If this changes,
913   // then this may need to be updated.
914   Builder.defineMacro("__clang_literal_encoding__", "\"UTF-8\"");
915   if (TI.getTypeWidth(TI.getWCharType()) >= 32) {
916     // FIXME: 32-bit wchar_t signals UTF-32. This may change
917     // if -fwide-exec-charset= is ever supported.
918     Builder.defineMacro("__clang_wide_literal_encoding__", "\"UTF-32\"");
919   } else {
920     // FIXME: Less-than 32-bit wchar_t generally means UTF-16
921     // (e.g., Windows, 32-bit IBM). This may need to be
922     // updated if -fwide-exec-charset= is ever supported.
923     Builder.defineMacro("__clang_wide_literal_encoding__", "\"UTF-16\"");
924   }
925 
926   if (LangOpts.Optimize)
927     Builder.defineMacro("__OPTIMIZE__");
928   if (LangOpts.OptimizeSize)
929     Builder.defineMacro("__OPTIMIZE_SIZE__");
930 
931   if (LangOpts.FastMath)
932     Builder.defineMacro("__FAST_MATH__");
933 
934   // Initialize target-specific preprocessor defines.
935 
936   // __BYTE_ORDER__ was added in GCC 4.6. It's analogous
937   // to the macro __BYTE_ORDER (no trailing underscores)
938   // from glibc's <endian.h> header.
939   // We don't support the PDP-11 as a target, but include
940   // the define so it can still be compared against.
941   Builder.defineMacro("__ORDER_LITTLE_ENDIAN__", "1234");
942   Builder.defineMacro("__ORDER_BIG_ENDIAN__",    "4321");
943   Builder.defineMacro("__ORDER_PDP_ENDIAN__",    "3412");
944   if (TI.isBigEndian()) {
945     Builder.defineMacro("__BYTE_ORDER__", "__ORDER_BIG_ENDIAN__");
946     Builder.defineMacro("__BIG_ENDIAN__");
947   } else {
948     Builder.defineMacro("__BYTE_ORDER__", "__ORDER_LITTLE_ENDIAN__");
949     Builder.defineMacro("__LITTLE_ENDIAN__");
950   }
951 
952   if (TI.getPointerWidth(LangAS::Default) == 64 && TI.getLongWidth() == 64 &&
953       TI.getIntWidth() == 32) {
954     Builder.defineMacro("_LP64");
955     Builder.defineMacro("__LP64__");
956   }
957 
958   if (TI.getPointerWidth(LangAS::Default) == 32 && TI.getLongWidth() == 32 &&
959       TI.getIntWidth() == 32) {
960     Builder.defineMacro("_ILP32");
961     Builder.defineMacro("__ILP32__");
962   }
963 
964   // Define type sizing macros based on the target properties.
965   assert(TI.getCharWidth() == 8 && "Only support 8-bit char so far");
966   Builder.defineMacro("__CHAR_BIT__", Twine(TI.getCharWidth()));
967 
968   Builder.defineMacro("__BOOL_WIDTH__", Twine(TI.getBoolWidth()));
969   Builder.defineMacro("__SHRT_WIDTH__", Twine(TI.getShortWidth()));
970   Builder.defineMacro("__INT_WIDTH__", Twine(TI.getIntWidth()));
971   Builder.defineMacro("__LONG_WIDTH__", Twine(TI.getLongWidth()));
972   Builder.defineMacro("__LLONG_WIDTH__", Twine(TI.getLongLongWidth()));
973 
974   size_t BitIntMaxWidth = TI.getMaxBitIntWidth();
975   assert(BitIntMaxWidth <= llvm::IntegerType::MAX_INT_BITS &&
976          "Target defined a max bit width larger than LLVM can support!");
977   assert(BitIntMaxWidth >= TI.getLongLongWidth() &&
978          "Target defined a max bit width smaller than the C standard allows!");
979   Builder.defineMacro("__BITINT_MAXWIDTH__", Twine(BitIntMaxWidth));
980 
981   DefineTypeSize("__SCHAR_MAX__", TargetInfo::SignedChar, TI, Builder);
982   DefineTypeSize("__SHRT_MAX__", TargetInfo::SignedShort, TI, Builder);
983   DefineTypeSize("__INT_MAX__", TargetInfo::SignedInt, TI, Builder);
984   DefineTypeSize("__LONG_MAX__", TargetInfo::SignedLong, TI, Builder);
985   DefineTypeSize("__LONG_LONG_MAX__", TargetInfo::SignedLongLong, TI, Builder);
986   DefineTypeSizeAndWidth("__WCHAR", TI.getWCharType(), TI, Builder);
987   DefineTypeSizeAndWidth("__WINT", TI.getWIntType(), TI, Builder);
988   DefineTypeSizeAndWidth("__INTMAX", TI.getIntMaxType(), TI, Builder);
989   DefineTypeSizeAndWidth("__SIZE", TI.getSizeType(), TI, Builder);
990 
991   DefineTypeSizeAndWidth("__UINTMAX", TI.getUIntMaxType(), TI, Builder);
992   DefineTypeSizeAndWidth("__PTRDIFF", TI.getPtrDiffType(LangAS::Default), TI,
993                          Builder);
994   DefineTypeSizeAndWidth("__INTPTR", TI.getIntPtrType(), TI, Builder);
995   DefineTypeSizeAndWidth("__UINTPTR", TI.getUIntPtrType(), TI, Builder);
996 
997   DefineTypeSizeof("__SIZEOF_DOUBLE__", TI.getDoubleWidth(), TI, Builder);
998   DefineTypeSizeof("__SIZEOF_FLOAT__", TI.getFloatWidth(), TI, Builder);
999   DefineTypeSizeof("__SIZEOF_INT__", TI.getIntWidth(), TI, Builder);
1000   DefineTypeSizeof("__SIZEOF_LONG__", TI.getLongWidth(), TI, Builder);
1001   DefineTypeSizeof("__SIZEOF_LONG_DOUBLE__",TI.getLongDoubleWidth(),TI,Builder);
1002   DefineTypeSizeof("__SIZEOF_LONG_LONG__", TI.getLongLongWidth(), TI, Builder);
1003   DefineTypeSizeof("__SIZEOF_POINTER__", TI.getPointerWidth(LangAS::Default),
1004                    TI, Builder);
1005   DefineTypeSizeof("__SIZEOF_SHORT__", TI.getShortWidth(), TI, Builder);
1006   DefineTypeSizeof("__SIZEOF_PTRDIFF_T__",
1007                    TI.getTypeWidth(TI.getPtrDiffType(LangAS::Default)), TI,
1008                    Builder);
1009   DefineTypeSizeof("__SIZEOF_SIZE_T__",
1010                    TI.getTypeWidth(TI.getSizeType()), TI, Builder);
1011   DefineTypeSizeof("__SIZEOF_WCHAR_T__",
1012                    TI.getTypeWidth(TI.getWCharType()), TI, Builder);
1013   DefineTypeSizeof("__SIZEOF_WINT_T__",
1014                    TI.getTypeWidth(TI.getWIntType()), TI, Builder);
1015   if (TI.hasInt128Type())
1016     DefineTypeSizeof("__SIZEOF_INT128__", 128, TI, Builder);
1017 
1018   DefineType("__INTMAX_TYPE__", TI.getIntMaxType(), Builder);
1019   DefineFmt("__INTMAX", TI.getIntMaxType(), TI, Builder);
1020   Builder.defineMacro("__INTMAX_C_SUFFIX__",
1021                       TI.getTypeConstantSuffix(TI.getIntMaxType()));
1022   DefineType("__UINTMAX_TYPE__", TI.getUIntMaxType(), Builder);
1023   DefineFmt("__UINTMAX", TI.getUIntMaxType(), TI, Builder);
1024   Builder.defineMacro("__UINTMAX_C_SUFFIX__",
1025                       TI.getTypeConstantSuffix(TI.getUIntMaxType()));
1026   DefineType("__PTRDIFF_TYPE__", TI.getPtrDiffType(LangAS::Default), Builder);
1027   DefineFmt("__PTRDIFF", TI.getPtrDiffType(LangAS::Default), TI, Builder);
1028   DefineType("__INTPTR_TYPE__", TI.getIntPtrType(), Builder);
1029   DefineFmt("__INTPTR", TI.getIntPtrType(), TI, Builder);
1030   DefineType("__SIZE_TYPE__", TI.getSizeType(), Builder);
1031   DefineFmt("__SIZE", TI.getSizeType(), TI, Builder);
1032   DefineType("__WCHAR_TYPE__", TI.getWCharType(), Builder);
1033   DefineType("__WINT_TYPE__", TI.getWIntType(), Builder);
1034   DefineTypeSizeAndWidth("__SIG_ATOMIC", TI.getSigAtomicType(), TI, Builder);
1035   DefineType("__CHAR16_TYPE__", TI.getChar16Type(), Builder);
1036   DefineType("__CHAR32_TYPE__", TI.getChar32Type(), Builder);
1037 
1038   DefineType("__UINTPTR_TYPE__", TI.getUIntPtrType(), Builder);
1039   DefineFmt("__UINTPTR", TI.getUIntPtrType(), TI, Builder);
1040 
1041   // The C standard requires the width of uintptr_t and intptr_t to be the same,
1042   // per 7.20.2.4p1. Same for intmax_t and uintmax_t, per 7.20.2.5p1.
1043   assert(TI.getTypeWidth(TI.getUIntPtrType()) ==
1044              TI.getTypeWidth(TI.getIntPtrType()) &&
1045          "uintptr_t and intptr_t have different widths?");
1046   assert(TI.getTypeWidth(TI.getUIntMaxType()) ==
1047              TI.getTypeWidth(TI.getIntMaxType()) &&
1048          "uintmax_t and intmax_t have different widths?");
1049 
1050   if (TI.hasFloat16Type())
1051     DefineFloatMacros(Builder, "FLT16", &TI.getHalfFormat(), "F16");
1052   DefineFloatMacros(Builder, "FLT", &TI.getFloatFormat(), "F");
1053   DefineFloatMacros(Builder, "DBL", &TI.getDoubleFormat(), "");
1054   DefineFloatMacros(Builder, "LDBL", &TI.getLongDoubleFormat(), "L");
1055 
1056   // Define a __POINTER_WIDTH__ macro for stdint.h.
1057   Builder.defineMacro("__POINTER_WIDTH__",
1058                       Twine((int)TI.getPointerWidth(LangAS::Default)));
1059 
1060   // Define __BIGGEST_ALIGNMENT__ to be compatible with gcc.
1061   Builder.defineMacro("__BIGGEST_ALIGNMENT__",
1062                       Twine(TI.getSuitableAlign() / TI.getCharWidth()) );
1063 
1064   if (!LangOpts.CharIsSigned)
1065     Builder.defineMacro("__CHAR_UNSIGNED__");
1066 
1067   if (!TargetInfo::isTypeSigned(TI.getWCharType()))
1068     Builder.defineMacro("__WCHAR_UNSIGNED__");
1069 
1070   if (!TargetInfo::isTypeSigned(TI.getWIntType()))
1071     Builder.defineMacro("__WINT_UNSIGNED__");
1072 
1073   // Define exact-width integer types for stdint.h
1074   DefineExactWidthIntType(TargetInfo::SignedChar, TI, Builder);
1075 
1076   if (TI.getShortWidth() > TI.getCharWidth())
1077     DefineExactWidthIntType(TargetInfo::SignedShort, TI, Builder);
1078 
1079   if (TI.getIntWidth() > TI.getShortWidth())
1080     DefineExactWidthIntType(TargetInfo::SignedInt, TI, Builder);
1081 
1082   if (TI.getLongWidth() > TI.getIntWidth())
1083     DefineExactWidthIntType(TargetInfo::SignedLong, TI, Builder);
1084 
1085   if (TI.getLongLongWidth() > TI.getLongWidth())
1086     DefineExactWidthIntType(TargetInfo::SignedLongLong, TI, Builder);
1087 
1088   DefineExactWidthIntType(TargetInfo::UnsignedChar, TI, Builder);
1089   DefineExactWidthIntTypeSize(TargetInfo::UnsignedChar, TI, Builder);
1090   DefineExactWidthIntTypeSize(TargetInfo::SignedChar, TI, Builder);
1091 
1092   if (TI.getShortWidth() > TI.getCharWidth()) {
1093     DefineExactWidthIntType(TargetInfo::UnsignedShort, TI, Builder);
1094     DefineExactWidthIntTypeSize(TargetInfo::UnsignedShort, TI, Builder);
1095     DefineExactWidthIntTypeSize(TargetInfo::SignedShort, TI, Builder);
1096   }
1097 
1098   if (TI.getIntWidth() > TI.getShortWidth()) {
1099     DefineExactWidthIntType(TargetInfo::UnsignedInt, TI, Builder);
1100     DefineExactWidthIntTypeSize(TargetInfo::UnsignedInt, TI, Builder);
1101     DefineExactWidthIntTypeSize(TargetInfo::SignedInt, TI, Builder);
1102   }
1103 
1104   if (TI.getLongWidth() > TI.getIntWidth()) {
1105     DefineExactWidthIntType(TargetInfo::UnsignedLong, TI, Builder);
1106     DefineExactWidthIntTypeSize(TargetInfo::UnsignedLong, TI, Builder);
1107     DefineExactWidthIntTypeSize(TargetInfo::SignedLong, TI, Builder);
1108   }
1109 
1110   if (TI.getLongLongWidth() > TI.getLongWidth()) {
1111     DefineExactWidthIntType(TargetInfo::UnsignedLongLong, TI, Builder);
1112     DefineExactWidthIntTypeSize(TargetInfo::UnsignedLongLong, TI, Builder);
1113     DefineExactWidthIntTypeSize(TargetInfo::SignedLongLong, TI, Builder);
1114   }
1115 
1116   DefineLeastWidthIntType(8, true, TI, Builder);
1117   DefineLeastWidthIntType(8, false, TI, Builder);
1118   DefineLeastWidthIntType(16, true, TI, Builder);
1119   DefineLeastWidthIntType(16, false, TI, Builder);
1120   DefineLeastWidthIntType(32, true, TI, Builder);
1121   DefineLeastWidthIntType(32, false, TI, Builder);
1122   DefineLeastWidthIntType(64, true, TI, Builder);
1123   DefineLeastWidthIntType(64, false, TI, Builder);
1124 
1125   DefineFastIntType(8, true, TI, Builder);
1126   DefineFastIntType(8, false, TI, Builder);
1127   DefineFastIntType(16, true, TI, Builder);
1128   DefineFastIntType(16, false, TI, Builder);
1129   DefineFastIntType(32, true, TI, Builder);
1130   DefineFastIntType(32, false, TI, Builder);
1131   DefineFastIntType(64, true, TI, Builder);
1132   DefineFastIntType(64, false, TI, Builder);
1133 
1134   Builder.defineMacro("__USER_LABEL_PREFIX__", TI.getUserLabelPrefix());
1135 
1136   if (!LangOpts.MathErrno)
1137     Builder.defineMacro("__NO_MATH_ERRNO__");
1138 
1139   if (LangOpts.FastMath || LangOpts.FiniteMathOnly)
1140     Builder.defineMacro("__FINITE_MATH_ONLY__", "1");
1141   else
1142     Builder.defineMacro("__FINITE_MATH_ONLY__", "0");
1143 
1144   if (LangOpts.GNUCVersion) {
1145     if (LangOpts.GNUInline || LangOpts.CPlusPlus)
1146       Builder.defineMacro("__GNUC_GNU_INLINE__");
1147     else
1148       Builder.defineMacro("__GNUC_STDC_INLINE__");
1149 
1150     // The value written by __atomic_test_and_set.
1151     // FIXME: This is target-dependent.
1152     Builder.defineMacro("__GCC_ATOMIC_TEST_AND_SET_TRUEVAL", "1");
1153   }
1154 
1155   auto addLockFreeMacros = [&](const llvm::Twine &Prefix) {
1156     // Used by libc++ and libstdc++ to implement ATOMIC_<foo>_LOCK_FREE.
1157 #define DEFINE_LOCK_FREE_MACRO(TYPE, Type)                                     \
1158   Builder.defineMacro(Prefix + #TYPE "_LOCK_FREE",                             \
1159                       getLockFreeValue(TI.get##Type##Width(), TI));
1160     DEFINE_LOCK_FREE_MACRO(BOOL, Bool);
1161     DEFINE_LOCK_FREE_MACRO(CHAR, Char);
1162     if (LangOpts.Char8)
1163       DEFINE_LOCK_FREE_MACRO(CHAR8_T, Char); // Treat char8_t like char.
1164     DEFINE_LOCK_FREE_MACRO(CHAR16_T, Char16);
1165     DEFINE_LOCK_FREE_MACRO(CHAR32_T, Char32);
1166     DEFINE_LOCK_FREE_MACRO(WCHAR_T, WChar);
1167     DEFINE_LOCK_FREE_MACRO(SHORT, Short);
1168     DEFINE_LOCK_FREE_MACRO(INT, Int);
1169     DEFINE_LOCK_FREE_MACRO(LONG, Long);
1170     DEFINE_LOCK_FREE_MACRO(LLONG, LongLong);
1171     Builder.defineMacro(
1172         Prefix + "POINTER_LOCK_FREE",
1173         getLockFreeValue(TI.getPointerWidth(LangAS::Default), TI));
1174 #undef DEFINE_LOCK_FREE_MACRO
1175   };
1176   addLockFreeMacros("__CLANG_ATOMIC_");
1177   if (LangOpts.GNUCVersion)
1178     addLockFreeMacros("__GCC_ATOMIC_");
1179 
1180   if (LangOpts.NoInlineDefine)
1181     Builder.defineMacro("__NO_INLINE__");
1182 
1183   if (unsigned PICLevel = LangOpts.PICLevel) {
1184     Builder.defineMacro("__PIC__", Twine(PICLevel));
1185     Builder.defineMacro("__pic__", Twine(PICLevel));
1186     if (LangOpts.PIE) {
1187       Builder.defineMacro("__PIE__", Twine(PICLevel));
1188       Builder.defineMacro("__pie__", Twine(PICLevel));
1189     }
1190   }
1191 
1192   // Macros to control C99 numerics and <float.h>
1193   Builder.defineMacro("__FLT_RADIX__", "2");
1194   Builder.defineMacro("__DECIMAL_DIG__", "__LDBL_DECIMAL_DIG__");
1195 
1196   if (LangOpts.getStackProtector() == LangOptions::SSPOn)
1197     Builder.defineMacro("__SSP__");
1198   else if (LangOpts.getStackProtector() == LangOptions::SSPStrong)
1199     Builder.defineMacro("__SSP_STRONG__", "2");
1200   else if (LangOpts.getStackProtector() == LangOptions::SSPReq)
1201     Builder.defineMacro("__SSP_ALL__", "3");
1202 
1203   if (PPOpts.SetUpStaticAnalyzer)
1204     Builder.defineMacro("__clang_analyzer__");
1205 
1206   if (LangOpts.FastRelaxedMath)
1207     Builder.defineMacro("__FAST_RELAXED_MATH__");
1208 
1209   if (FEOpts.ProgramAction == frontend::RewriteObjC ||
1210       LangOpts.getGC() != LangOptions::NonGC) {
1211     Builder.defineMacro("__weak", "__attribute__((objc_gc(weak)))");
1212     Builder.defineMacro("__strong", "__attribute__((objc_gc(strong)))");
1213     Builder.defineMacro("__autoreleasing", "");
1214     Builder.defineMacro("__unsafe_unretained", "");
1215   } else if (LangOpts.ObjC) {
1216     Builder.defineMacro("__weak", "__attribute__((objc_ownership(weak)))");
1217     Builder.defineMacro("__strong", "__attribute__((objc_ownership(strong)))");
1218     Builder.defineMacro("__autoreleasing",
1219                         "__attribute__((objc_ownership(autoreleasing)))");
1220     Builder.defineMacro("__unsafe_unretained",
1221                         "__attribute__((objc_ownership(none)))");
1222   }
1223 
1224   // On Darwin, there are __double_underscored variants of the type
1225   // nullability qualifiers.
1226   if (TI.getTriple().isOSDarwin()) {
1227     Builder.defineMacro("__nonnull", "_Nonnull");
1228     Builder.defineMacro("__null_unspecified", "_Null_unspecified");
1229     Builder.defineMacro("__nullable", "_Nullable");
1230   }
1231 
1232   // Add a macro to differentiate between regular iOS/tvOS/watchOS targets and
1233   // the corresponding simulator targets.
1234   if (TI.getTriple().isOSDarwin() && TI.getTriple().isSimulatorEnvironment())
1235     Builder.defineMacro("__APPLE_EMBEDDED_SIMULATOR__", "1");
1236 
1237   // OpenMP definition
1238   // OpenMP 2.2:
1239   //   In implementations that support a preprocessor, the _OPENMP
1240   //   macro name is defined to have the decimal value yyyymm where
1241   //   yyyy and mm are the year and the month designations of the
1242   //   version of the OpenMP API that the implementation support.
1243   if (!LangOpts.OpenMPSimd) {
1244     switch (LangOpts.OpenMP) {
1245     case 0:
1246       break;
1247     case 31:
1248       Builder.defineMacro("_OPENMP", "201107");
1249       break;
1250     case 40:
1251       Builder.defineMacro("_OPENMP", "201307");
1252       break;
1253     case 45:
1254       Builder.defineMacro("_OPENMP", "201511");
1255       break;
1256     case 50:
1257       Builder.defineMacro("_OPENMP", "201811");
1258       break;
1259     case 52:
1260       Builder.defineMacro("_OPENMP", "202111");
1261       break;
1262     default: // case 51:
1263       // Default version is OpenMP 5.1
1264       Builder.defineMacro("_OPENMP", "202011");
1265       break;
1266     }
1267   }
1268 
1269   // CUDA device path compilaton
1270   if (LangOpts.CUDAIsDevice && !LangOpts.HIP) {
1271     // The CUDA_ARCH value is set for the GPU target specified in the NVPTX
1272     // backend's target defines.
1273     Builder.defineMacro("__CUDA_ARCH__");
1274   }
1275 
1276   // We need to communicate this to our CUDA header wrapper, which in turn
1277   // informs the proper CUDA headers of this choice.
1278   if (LangOpts.CUDADeviceApproxTranscendentals || LangOpts.FastMath) {
1279     Builder.defineMacro("__CLANG_CUDA_APPROX_TRANSCENDENTALS__");
1280   }
1281 
1282   // Define a macro indicating that the source file is being compiled with a
1283   // SYCL device compiler which doesn't produce host binary.
1284   if (LangOpts.SYCLIsDevice) {
1285     Builder.defineMacro("__SYCL_DEVICE_ONLY__", "1");
1286   }
1287 
1288   // OpenCL definitions.
1289   if (LangOpts.OpenCL) {
1290     InitializeOpenCLFeatureTestMacros(TI, LangOpts, Builder);
1291 
1292     if (TI.getTriple().isSPIR() || TI.getTriple().isSPIRV())
1293       Builder.defineMacro("__IMAGE_SUPPORT__");
1294   }
1295 
1296   if (TI.hasInt128Type() && LangOpts.CPlusPlus && LangOpts.GNUMode) {
1297     // For each extended integer type, g++ defines a macro mapping the
1298     // index of the type (0 in this case) in some list of extended types
1299     // to the type.
1300     Builder.defineMacro("__GLIBCXX_TYPE_INT_N_0", "__int128");
1301     Builder.defineMacro("__GLIBCXX_BITSIZE_INT_N_0", "128");
1302   }
1303 
1304   // ELF targets define __ELF__
1305   if (TI.getTriple().isOSBinFormatELF())
1306     Builder.defineMacro("__ELF__");
1307 
1308   // Get other target #defines.
1309   TI.getTargetDefines(LangOpts, Builder);
1310 }
1311 
1312 /// InitializePreprocessor - Initialize the preprocessor getting it and the
1313 /// environment ready to process a single file.
1314 void clang::InitializePreprocessor(
1315     Preprocessor &PP, const PreprocessorOptions &InitOpts,
1316     const PCHContainerReader &PCHContainerRdr,
1317     const FrontendOptions &FEOpts) {
1318   const LangOptions &LangOpts = PP.getLangOpts();
1319   std::string PredefineBuffer;
1320   PredefineBuffer.reserve(4080);
1321   llvm::raw_string_ostream Predefines(PredefineBuffer);
1322   MacroBuilder Builder(Predefines);
1323 
1324   // Emit line markers for various builtin sections of the file. The 3 here
1325   // marks <built-in> as being a system header, which suppresses warnings when
1326   // the same macro is defined multiple times.
1327   Builder.append("# 1 \"<built-in>\" 3");
1328 
1329   // Install things like __POWERPC__, __GNUC__, etc into the macro table.
1330   if (InitOpts.UsePredefines) {
1331     // FIXME: This will create multiple definitions for most of the predefined
1332     // macros. This is not the right way to handle this.
1333     if ((LangOpts.CUDA || LangOpts.OpenMPIsDevice || LangOpts.SYCLIsDevice) &&
1334         PP.getAuxTargetInfo())
1335       InitializePredefinedMacros(*PP.getAuxTargetInfo(), LangOpts, FEOpts,
1336                                  PP.getPreprocessorOpts(), Builder);
1337 
1338     InitializePredefinedMacros(PP.getTargetInfo(), LangOpts, FEOpts,
1339                                PP.getPreprocessorOpts(), Builder);
1340 
1341     // Install definitions to make Objective-C++ ARC work well with various
1342     // C++ Standard Library implementations.
1343     if (LangOpts.ObjC && LangOpts.CPlusPlus &&
1344         (LangOpts.ObjCAutoRefCount || LangOpts.ObjCWeak)) {
1345       switch (InitOpts.ObjCXXARCStandardLibrary) {
1346       case ARCXX_nolib:
1347       case ARCXX_libcxx:
1348         break;
1349 
1350       case ARCXX_libstdcxx:
1351         AddObjCXXARCLibstdcxxDefines(LangOpts, Builder);
1352         break;
1353       }
1354     }
1355   }
1356 
1357   // Even with predefines off, some macros are still predefined.
1358   // These should all be defined in the preprocessor according to the
1359   // current language configuration.
1360   InitializeStandardPredefinedMacros(PP.getTargetInfo(), PP.getLangOpts(),
1361                                      FEOpts, Builder);
1362 
1363   // Add on the predefines from the driver.  Wrap in a #line directive to report
1364   // that they come from the command line.
1365   Builder.append("# 1 \"<command line>\" 1");
1366 
1367   // Process #define's and #undef's in the order they are given.
1368   for (unsigned i = 0, e = InitOpts.Macros.size(); i != e; ++i) {
1369     if (InitOpts.Macros[i].second)  // isUndef
1370       Builder.undefineMacro(InitOpts.Macros[i].first);
1371     else
1372       DefineBuiltinMacro(Builder, InitOpts.Macros[i].first,
1373                          PP.getDiagnostics());
1374   }
1375 
1376   // Exit the command line and go back to <built-in> (2 is LC_LEAVE).
1377   Builder.append("# 1 \"<built-in>\" 2");
1378 
1379   // If -imacros are specified, include them now.  These are processed before
1380   // any -include directives.
1381   for (unsigned i = 0, e = InitOpts.MacroIncludes.size(); i != e; ++i)
1382     AddImplicitIncludeMacros(Builder, InitOpts.MacroIncludes[i]);
1383 
1384   // Process -include-pch/-include-pth directives.
1385   if (!InitOpts.ImplicitPCHInclude.empty())
1386     AddImplicitIncludePCH(Builder, PP, PCHContainerRdr,
1387                           InitOpts.ImplicitPCHInclude);
1388 
1389   // Process -include directives.
1390   for (unsigned i = 0, e = InitOpts.Includes.size(); i != e; ++i) {
1391     const std::string &Path = InitOpts.Includes[i];
1392     AddImplicitInclude(Builder, Path);
1393   }
1394 
1395   // Instruct the preprocessor to skip the preamble.
1396   PP.setSkipMainFilePreamble(InitOpts.PrecompiledPreambleBytes.first,
1397                              InitOpts.PrecompiledPreambleBytes.second);
1398 
1399   // Copy PredefinedBuffer into the Preprocessor.
1400   PP.setPredefines(std::move(PredefineBuffer));
1401 }
1402