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     if (LangOpts.C23)
442       Builder.defineMacro("__STDC_VERSION__", "202311L");
443     else if (LangOpts.C17)
444       Builder.defineMacro("__STDC_VERSION__", "201710L");
445     else if (LangOpts.C11)
446       Builder.defineMacro("__STDC_VERSION__", "201112L");
447     else if (LangOpts.C99)
448       Builder.defineMacro("__STDC_VERSION__", "199901L");
449     else if (!LangOpts.GNUMode && LangOpts.Digraphs)
450       Builder.defineMacro("__STDC_VERSION__", "199409L");
451   } else {
452     //   -- __cplusplus
453     if (LangOpts.CPlusPlus26)
454       // FIXME: Use correct value for C++26.
455       Builder.defineMacro("__cplusplus", "202400L");
456     else if (LangOpts.CPlusPlus23)
457       Builder.defineMacro("__cplusplus", "202302L");
458     //      [C++20] The integer literal 202002L.
459     else if (LangOpts.CPlusPlus20)
460       Builder.defineMacro("__cplusplus", "202002L");
461     //      [C++17] The integer literal 201703L.
462     else if (LangOpts.CPlusPlus17)
463       Builder.defineMacro("__cplusplus", "201703L");
464     //      [C++14] The name __cplusplus is defined to the value 201402L when
465     //      compiling a C++ translation unit.
466     else if (LangOpts.CPlusPlus14)
467       Builder.defineMacro("__cplusplus", "201402L");
468     //      [C++11] The name __cplusplus is defined to the value 201103L when
469     //      compiling a C++ translation unit.
470     else if (LangOpts.CPlusPlus11)
471       Builder.defineMacro("__cplusplus", "201103L");
472     //      [C++03] The name __cplusplus is defined to the value 199711L when
473     //      compiling a C++ translation unit.
474     else
475       Builder.defineMacro("__cplusplus", "199711L");
476 
477     //   -- __STDCPP_DEFAULT_NEW_ALIGNMENT__
478     //      [C++17] An integer literal of type std::size_t whose value is the
479     //      alignment guaranteed by a call to operator new(std::size_t)
480     //
481     // We provide this in all language modes, since it seems generally useful.
482     Builder.defineMacro("__STDCPP_DEFAULT_NEW_ALIGNMENT__",
483                         Twine(TI.getNewAlign() / TI.getCharWidth()) +
484                             TI.getTypeConstantSuffix(TI.getSizeType()));
485 
486     //   -- __STDCPP_­THREADS__
487     //      Defined, and has the value integer literal 1, if and only if a
488     //      program can have more than one thread of execution.
489     if (LangOpts.getThreadModel() == LangOptions::ThreadModelKind::POSIX)
490       Builder.defineMacro("__STDCPP_THREADS__", "1");
491   }
492 
493   // In C11 these are environment macros. In C++11 they are only defined
494   // as part of <cuchar>. To prevent breakage when mixing C and C++
495   // code, define these macros unconditionally. We can define them
496   // unconditionally, as Clang always uses UTF-16 and UTF-32 for 16-bit
497   // and 32-bit character literals.
498   Builder.defineMacro("__STDC_UTF_16__", "1");
499   Builder.defineMacro("__STDC_UTF_32__", "1");
500 
501   if (LangOpts.ObjC)
502     Builder.defineMacro("__OBJC__");
503 
504   // OpenCL v1.0/1.1 s6.9, v1.2/2.0 s6.10: Preprocessor Directives and Macros.
505   if (LangOpts.OpenCL) {
506     if (LangOpts.CPlusPlus) {
507       switch (LangOpts.OpenCLCPlusPlusVersion) {
508       case 100:
509         Builder.defineMacro("__OPENCL_CPP_VERSION__", "100");
510         break;
511       case 202100:
512         Builder.defineMacro("__OPENCL_CPP_VERSION__", "202100");
513         break;
514       default:
515         llvm_unreachable("Unsupported C++ version for OpenCL");
516       }
517       Builder.defineMacro("__CL_CPP_VERSION_1_0__", "100");
518       Builder.defineMacro("__CL_CPP_VERSION_2021__", "202100");
519     } else {
520       // OpenCL v1.0 and v1.1 do not have a predefined macro to indicate the
521       // language standard with which the program is compiled. __OPENCL_VERSION__
522       // is for the OpenCL version supported by the OpenCL device, which is not
523       // necessarily the language standard with which the program is compiled.
524       // A shared OpenCL header file requires a macro to indicate the language
525       // standard. As a workaround, __OPENCL_C_VERSION__ is defined for
526       // OpenCL v1.0 and v1.1.
527       switch (LangOpts.OpenCLVersion) {
528       case 100:
529         Builder.defineMacro("__OPENCL_C_VERSION__", "100");
530         break;
531       case 110:
532         Builder.defineMacro("__OPENCL_C_VERSION__", "110");
533         break;
534       case 120:
535         Builder.defineMacro("__OPENCL_C_VERSION__", "120");
536         break;
537       case 200:
538         Builder.defineMacro("__OPENCL_C_VERSION__", "200");
539         break;
540       case 300:
541         Builder.defineMacro("__OPENCL_C_VERSION__", "300");
542         break;
543       default:
544         llvm_unreachable("Unsupported OpenCL version");
545       }
546     }
547     Builder.defineMacro("CL_VERSION_1_0", "100");
548     Builder.defineMacro("CL_VERSION_1_1", "110");
549     Builder.defineMacro("CL_VERSION_1_2", "120");
550     Builder.defineMacro("CL_VERSION_2_0", "200");
551     Builder.defineMacro("CL_VERSION_3_0", "300");
552 
553     if (TI.isLittleEndian())
554       Builder.defineMacro("__ENDIAN_LITTLE__");
555 
556     if (LangOpts.FastRelaxedMath)
557       Builder.defineMacro("__FAST_RELAXED_MATH__");
558   }
559 
560   if (LangOpts.SYCLIsDevice || LangOpts.SYCLIsHost) {
561     // SYCL Version is set to a value when building SYCL applications
562     if (LangOpts.getSYCLVersion() == LangOptions::SYCL_2017)
563       Builder.defineMacro("CL_SYCL_LANGUAGE_VERSION", "121");
564     else if (LangOpts.getSYCLVersion() == LangOptions::SYCL_2020)
565       Builder.defineMacro("SYCL_LANGUAGE_VERSION", "202001");
566   }
567 
568   // Not "standard" per se, but available even with the -undef flag.
569   if (LangOpts.AsmPreprocessor)
570     Builder.defineMacro("__ASSEMBLER__");
571   if (LangOpts.CUDA) {
572     if (LangOpts.GPURelocatableDeviceCode)
573       Builder.defineMacro("__CLANG_RDC__");
574     if (!LangOpts.HIP)
575       Builder.defineMacro("__CUDA__");
576     if (LangOpts.GPUDefaultStream ==
577         LangOptions::GPUDefaultStreamKind::PerThread)
578       Builder.defineMacro("CUDA_API_PER_THREAD_DEFAULT_STREAM");
579   }
580   if (LangOpts.HIP) {
581     Builder.defineMacro("__HIP__");
582     Builder.defineMacro("__HIPCC__");
583     Builder.defineMacro("__HIP_MEMORY_SCOPE_SINGLETHREAD", "1");
584     Builder.defineMacro("__HIP_MEMORY_SCOPE_WAVEFRONT", "2");
585     Builder.defineMacro("__HIP_MEMORY_SCOPE_WORKGROUP", "3");
586     Builder.defineMacro("__HIP_MEMORY_SCOPE_AGENT", "4");
587     Builder.defineMacro("__HIP_MEMORY_SCOPE_SYSTEM", "5");
588     if (LangOpts.HIPStdPar) {
589       Builder.defineMacro("__HIPSTDPAR__");
590       if (LangOpts.HIPStdParInterposeAlloc)
591         Builder.defineMacro("__HIPSTDPAR_INTERPOSE_ALLOC__");
592     }
593     if (LangOpts.CUDAIsDevice) {
594       Builder.defineMacro("__HIP_DEVICE_COMPILE__");
595       if (!TI.hasHIPImageSupport()) {
596         Builder.defineMacro("__HIP_NO_IMAGE_SUPPORT__", "1");
597         // Deprecated.
598         Builder.defineMacro("__HIP_NO_IMAGE_SUPPORT", "1");
599       }
600     }
601     if (LangOpts.GPUDefaultStream ==
602         LangOptions::GPUDefaultStreamKind::PerThread) {
603       Builder.defineMacro("__HIP_API_PER_THREAD_DEFAULT_STREAM__");
604       // Deprecated.
605       Builder.defineMacro("HIP_API_PER_THREAD_DEFAULT_STREAM");
606     }
607   }
608 
609   if (LangOpts.OpenACC) {
610     // FIXME: When we have full support for OpenACC, we should set this to the
611     // version we support. Until then, set as '1' by default, but provide a
612     // temporary mechanism for users to override this so real-world examples can
613     // be tested against.
614     if (!LangOpts.OpenACCMacroOverride.empty())
615       Builder.defineMacro("_OPENACC", LangOpts.OpenACCMacroOverride);
616     else
617       Builder.defineMacro("_OPENACC", "1");
618   }
619 }
620 
621 /// Initialize the predefined C++ language feature test macros defined in
622 /// ISO/IEC JTC1/SC22/WG21 (C++) SD-6: "SG10 Feature Test Recommendations".
623 static void InitializeCPlusPlusFeatureTestMacros(const LangOptions &LangOpts,
624                                                  MacroBuilder &Builder) {
625   // C++98 features.
626   if (LangOpts.RTTI)
627     Builder.defineMacro("__cpp_rtti", "199711L");
628   if (LangOpts.CXXExceptions)
629     Builder.defineMacro("__cpp_exceptions", "199711L");
630 
631   // C++11 features.
632   if (LangOpts.CPlusPlus11) {
633     Builder.defineMacro("__cpp_unicode_characters", "200704L");
634     Builder.defineMacro("__cpp_raw_strings", "200710L");
635     Builder.defineMacro("__cpp_unicode_literals", "200710L");
636     Builder.defineMacro("__cpp_user_defined_literals", "200809L");
637     Builder.defineMacro("__cpp_lambdas", "200907L");
638     Builder.defineMacro("__cpp_constexpr", LangOpts.CPlusPlus26   ? "202306L"
639                                            : LangOpts.CPlusPlus23 ? "202211L"
640                                            : LangOpts.CPlusPlus20 ? "201907L"
641                                            : LangOpts.CPlusPlus17 ? "201603L"
642                                            : LangOpts.CPlusPlus14 ? "201304L"
643                                                                   : "200704");
644     Builder.defineMacro("__cpp_constexpr_in_decltype", "201711L");
645     Builder.defineMacro("__cpp_range_based_for",
646                         LangOpts.CPlusPlus17 ? "201603L" : "200907");
647     Builder.defineMacro("__cpp_static_assert", LangOpts.CPlusPlus26 ? "202306L"
648                                                : LangOpts.CPlusPlus17
649                                                    ? "201411L"
650                                                    : "200410");
651     Builder.defineMacro("__cpp_decltype", "200707L");
652     Builder.defineMacro("__cpp_attributes", "200809L");
653     Builder.defineMacro("__cpp_rvalue_references", "200610L");
654     Builder.defineMacro("__cpp_variadic_templates", "200704L");
655     Builder.defineMacro("__cpp_initializer_lists", "200806L");
656     Builder.defineMacro("__cpp_delegating_constructors", "200604L");
657     Builder.defineMacro("__cpp_nsdmi", "200809L");
658     Builder.defineMacro("__cpp_inheriting_constructors", "201511L");
659     Builder.defineMacro("__cpp_ref_qualifiers", "200710L");
660     Builder.defineMacro("__cpp_alias_templates", "200704L");
661   }
662   if (LangOpts.ThreadsafeStatics)
663     Builder.defineMacro("__cpp_threadsafe_static_init", "200806L");
664 
665   // C++14 features.
666   if (LangOpts.CPlusPlus14) {
667     Builder.defineMacro("__cpp_binary_literals", "201304L");
668     Builder.defineMacro("__cpp_digit_separators", "201309L");
669     Builder.defineMacro("__cpp_init_captures",
670                         LangOpts.CPlusPlus20 ? "201803L" : "201304L");
671     Builder.defineMacro("__cpp_generic_lambdas",
672                         LangOpts.CPlusPlus20 ? "201707L" : "201304L");
673     Builder.defineMacro("__cpp_decltype_auto", "201304L");
674     Builder.defineMacro("__cpp_return_type_deduction", "201304L");
675     Builder.defineMacro("__cpp_aggregate_nsdmi", "201304L");
676     Builder.defineMacro("__cpp_variable_templates", "201304L");
677   }
678   if (LangOpts.SizedDeallocation)
679     Builder.defineMacro("__cpp_sized_deallocation", "201309L");
680 
681   // C++17 features.
682   if (LangOpts.CPlusPlus17) {
683     Builder.defineMacro("__cpp_hex_float", "201603L");
684     Builder.defineMacro("__cpp_inline_variables", "201606L");
685     Builder.defineMacro("__cpp_noexcept_function_type", "201510L");
686     Builder.defineMacro("__cpp_capture_star_this", "201603L");
687     Builder.defineMacro("__cpp_if_constexpr", "201606L");
688     Builder.defineMacro("__cpp_deduction_guides", "201703L"); // (not latest)
689     Builder.defineMacro("__cpp_template_auto", "201606L"); // (old name)
690     Builder.defineMacro("__cpp_namespace_attributes", "201411L");
691     Builder.defineMacro("__cpp_enumerator_attributes", "201411L");
692     Builder.defineMacro("__cpp_nested_namespace_definitions", "201411L");
693     Builder.defineMacro("__cpp_variadic_using", "201611L");
694     Builder.defineMacro("__cpp_aggregate_bases", "201603L");
695     Builder.defineMacro("__cpp_structured_bindings", "201606L");
696     Builder.defineMacro("__cpp_nontype_template_args",
697                         "201411L"); // (not latest)
698     Builder.defineMacro("__cpp_fold_expressions", "201603L");
699     Builder.defineMacro("__cpp_guaranteed_copy_elision", "201606L");
700     Builder.defineMacro("__cpp_nontype_template_parameter_auto", "201606L");
701   }
702   if (LangOpts.AlignedAllocation && !LangOpts.AlignedAllocationUnavailable)
703     Builder.defineMacro("__cpp_aligned_new", "201606L");
704   if (LangOpts.RelaxedTemplateTemplateArgs)
705     Builder.defineMacro("__cpp_template_template_args", "201611L");
706 
707   // C++20 features.
708   if (LangOpts.CPlusPlus20) {
709     Builder.defineMacro("__cpp_aggregate_paren_init", "201902L");
710 
711     // P0848 is implemented, but we're still waiting for other concepts
712     // issues to be addressed before bumping __cpp_concepts up to 202002L.
713     // Refer to the discussion of this at https://reviews.llvm.org/D128619.
714     Builder.defineMacro("__cpp_concepts", "201907L");
715     Builder.defineMacro("__cpp_conditional_explicit", "201806L");
716     Builder.defineMacro("__cpp_consteval", "202211L");
717     Builder.defineMacro("__cpp_constexpr_dynamic_alloc", "201907L");
718     Builder.defineMacro("__cpp_constinit", "201907L");
719     Builder.defineMacro("__cpp_impl_coroutine", "201902L");
720     Builder.defineMacro("__cpp_designated_initializers", "201707L");
721     Builder.defineMacro("__cpp_impl_three_way_comparison", "201907L");
722     //Builder.defineMacro("__cpp_modules", "201907L");
723     Builder.defineMacro("__cpp_using_enum", "201907L");
724   }
725   // C++23 features.
726   if (LangOpts.CPlusPlus23) {
727     Builder.defineMacro("__cpp_implicit_move", "202011L");
728     Builder.defineMacro("__cpp_size_t_suffix", "202011L");
729     Builder.defineMacro("__cpp_if_consteval", "202106L");
730     Builder.defineMacro("__cpp_multidimensional_subscript", "202211L");
731     Builder.defineMacro("__cpp_auto_cast", "202110L");
732   }
733 
734   // We provide those C++23 features as extensions in earlier language modes, so
735   // we also define their feature test macros.
736   if (LangOpts.CPlusPlus11)
737     Builder.defineMacro("__cpp_static_call_operator", "202207L");
738   Builder.defineMacro("__cpp_named_character_escapes", "202207L");
739   Builder.defineMacro("__cpp_placeholder_variables", "202306L");
740 
741   if (LangOpts.Char8)
742     Builder.defineMacro("__cpp_char8_t", "202207L");
743   Builder.defineMacro("__cpp_impl_destroying_delete", "201806L");
744 }
745 
746 /// InitializeOpenCLFeatureTestMacros - Define OpenCL macros based on target
747 /// settings and language version
748 void InitializeOpenCLFeatureTestMacros(const TargetInfo &TI,
749                                        const LangOptions &Opts,
750                                        MacroBuilder &Builder) {
751   const llvm::StringMap<bool> &OpenCLFeaturesMap = TI.getSupportedOpenCLOpts();
752   // FIXME: OpenCL options which affect language semantics/syntax
753   // should be moved into LangOptions.
754   auto defineOpenCLExtMacro = [&](llvm::StringRef Name, auto... OptArgs) {
755     // Check if extension is supported by target and is available in this
756     // OpenCL version
757     if (TI.hasFeatureEnabled(OpenCLFeaturesMap, Name) &&
758         OpenCLOptions::isOpenCLOptionAvailableIn(Opts, OptArgs...))
759       Builder.defineMacro(Name);
760   };
761 #define OPENCL_GENERIC_EXTENSION(Ext, ...)                                     \
762   defineOpenCLExtMacro(#Ext, __VA_ARGS__);
763 #include "clang/Basic/OpenCLExtensions.def"
764 
765   // Assume compiling for FULL profile
766   Builder.defineMacro("__opencl_c_int64");
767 }
768 
769 static void InitializePredefinedMacros(const TargetInfo &TI,
770                                        const LangOptions &LangOpts,
771                                        const FrontendOptions &FEOpts,
772                                        const PreprocessorOptions &PPOpts,
773                                        MacroBuilder &Builder) {
774   // Compiler version introspection macros.
775   Builder.defineMacro("__llvm__");  // LLVM Backend
776   Builder.defineMacro("__clang__"); // Clang Frontend
777 #define TOSTR2(X) #X
778 #define TOSTR(X) TOSTR2(X)
779   Builder.defineMacro("__clang_major__", TOSTR(CLANG_VERSION_MAJOR));
780   Builder.defineMacro("__clang_minor__", TOSTR(CLANG_VERSION_MINOR));
781   Builder.defineMacro("__clang_patchlevel__", TOSTR(CLANG_VERSION_PATCHLEVEL));
782 #undef TOSTR
783 #undef TOSTR2
784   Builder.defineMacro("__clang_version__",
785                       "\"" CLANG_VERSION_STRING " "
786                       + getClangFullRepositoryVersion() + "\"");
787 
788   if (LangOpts.GNUCVersion != 0) {
789     // Major, minor, patch, are given two decimal places each, so 4.2.1 becomes
790     // 40201.
791     unsigned GNUCMajor = LangOpts.GNUCVersion / 100 / 100;
792     unsigned GNUCMinor = LangOpts.GNUCVersion / 100 % 100;
793     unsigned GNUCPatch = LangOpts.GNUCVersion % 100;
794     Builder.defineMacro("__GNUC__", Twine(GNUCMajor));
795     Builder.defineMacro("__GNUC_MINOR__", Twine(GNUCMinor));
796     Builder.defineMacro("__GNUC_PATCHLEVEL__", Twine(GNUCPatch));
797     Builder.defineMacro("__GXX_ABI_VERSION", "1002");
798 
799     if (LangOpts.CPlusPlus) {
800       Builder.defineMacro("__GNUG__", Twine(GNUCMajor));
801       Builder.defineMacro("__GXX_WEAK__");
802     }
803   }
804 
805   // Define macros for the C11 / C++11 memory orderings
806   Builder.defineMacro("__ATOMIC_RELAXED", "0");
807   Builder.defineMacro("__ATOMIC_CONSUME", "1");
808   Builder.defineMacro("__ATOMIC_ACQUIRE", "2");
809   Builder.defineMacro("__ATOMIC_RELEASE", "3");
810   Builder.defineMacro("__ATOMIC_ACQ_REL", "4");
811   Builder.defineMacro("__ATOMIC_SEQ_CST", "5");
812 
813   // Define macros for the clang atomic scopes.
814   Builder.defineMacro("__MEMORY_SCOPE_SYSTEM", "0");
815   Builder.defineMacro("__MEMORY_SCOPE_DEVICE", "1");
816   Builder.defineMacro("__MEMORY_SCOPE_WRKGRP", "2");
817   Builder.defineMacro("__MEMORY_SCOPE_WVFRNT", "3");
818   Builder.defineMacro("__MEMORY_SCOPE_SINGLE", "4");
819 
820   // Define macros for the OpenCL memory scope.
821   // The values should match AtomicScopeOpenCLModel::ID enum.
822   static_assert(
823       static_cast<unsigned>(AtomicScopeOpenCLModel::WorkGroup) == 1 &&
824           static_cast<unsigned>(AtomicScopeOpenCLModel::Device) == 2 &&
825           static_cast<unsigned>(AtomicScopeOpenCLModel::AllSVMDevices) == 3 &&
826           static_cast<unsigned>(AtomicScopeOpenCLModel::SubGroup) == 4,
827       "Invalid OpenCL memory scope enum definition");
828   Builder.defineMacro("__OPENCL_MEMORY_SCOPE_WORK_ITEM", "0");
829   Builder.defineMacro("__OPENCL_MEMORY_SCOPE_WORK_GROUP", "1");
830   Builder.defineMacro("__OPENCL_MEMORY_SCOPE_DEVICE", "2");
831   Builder.defineMacro("__OPENCL_MEMORY_SCOPE_ALL_SVM_DEVICES", "3");
832   Builder.defineMacro("__OPENCL_MEMORY_SCOPE_SUB_GROUP", "4");
833 
834   // Define macros for floating-point data classes, used in __builtin_isfpclass.
835   Builder.defineMacro("__FPCLASS_SNAN", "0x0001");
836   Builder.defineMacro("__FPCLASS_QNAN", "0x0002");
837   Builder.defineMacro("__FPCLASS_NEGINF", "0x0004");
838   Builder.defineMacro("__FPCLASS_NEGNORMAL", "0x0008");
839   Builder.defineMacro("__FPCLASS_NEGSUBNORMAL", "0x0010");
840   Builder.defineMacro("__FPCLASS_NEGZERO", "0x0020");
841   Builder.defineMacro("__FPCLASS_POSZERO", "0x0040");
842   Builder.defineMacro("__FPCLASS_POSSUBNORMAL", "0x0080");
843   Builder.defineMacro("__FPCLASS_POSNORMAL", "0x0100");
844   Builder.defineMacro("__FPCLASS_POSINF", "0x0200");
845 
846   // Support for #pragma redefine_extname (Sun compatibility)
847   Builder.defineMacro("__PRAGMA_REDEFINE_EXTNAME", "1");
848 
849   // Previously this macro was set to a string aiming to achieve compatibility
850   // with GCC 4.2.1. Now, just return the full Clang version
851   Builder.defineMacro("__VERSION__", "\"" +
852                       Twine(getClangFullCPPVersion()) + "\"");
853 
854   // Initialize language-specific preprocessor defines.
855 
856   // Standard conforming mode?
857   if (!LangOpts.GNUMode && !LangOpts.MSVCCompat)
858     Builder.defineMacro("__STRICT_ANSI__");
859 
860   if (LangOpts.GNUCVersion && LangOpts.CPlusPlus11)
861     Builder.defineMacro("__GXX_EXPERIMENTAL_CXX0X__");
862 
863   if (LangOpts.ObjC) {
864     if (LangOpts.ObjCRuntime.isNonFragile()) {
865       Builder.defineMacro("__OBJC2__");
866 
867       if (LangOpts.ObjCExceptions)
868         Builder.defineMacro("OBJC_ZEROCOST_EXCEPTIONS");
869     }
870 
871     if (LangOpts.getGC() != LangOptions::NonGC)
872       Builder.defineMacro("__OBJC_GC__");
873 
874     if (LangOpts.ObjCRuntime.isNeXTFamily())
875       Builder.defineMacro("__NEXT_RUNTIME__");
876 
877     if (LangOpts.ObjCRuntime.getKind() == ObjCRuntime::GNUstep) {
878       auto version = LangOpts.ObjCRuntime.getVersion();
879       std::string versionString = "1";
880       // Don't rely on the tuple argument, because we can be asked to target
881       // later ABIs than we actually support, so clamp these values to those
882       // currently supported
883       if (version >= VersionTuple(2, 0))
884         Builder.defineMacro("__OBJC_GNUSTEP_RUNTIME_ABI__", "20");
885       else
886         Builder.defineMacro(
887             "__OBJC_GNUSTEP_RUNTIME_ABI__",
888             "1" + Twine(std::min(8U, version.getMinor().value_or(0))));
889     }
890 
891     if (LangOpts.ObjCRuntime.getKind() == ObjCRuntime::ObjFW) {
892       VersionTuple tuple = LangOpts.ObjCRuntime.getVersion();
893       unsigned minor = tuple.getMinor().value_or(0);
894       unsigned subminor = tuple.getSubminor().value_or(0);
895       Builder.defineMacro("__OBJFW_RUNTIME_ABI__",
896                           Twine(tuple.getMajor() * 10000 + minor * 100 +
897                                 subminor));
898     }
899 
900     Builder.defineMacro("IBOutlet", "__attribute__((iboutlet))");
901     Builder.defineMacro("IBOutletCollection(ClassName)",
902                         "__attribute__((iboutletcollection(ClassName)))");
903     Builder.defineMacro("IBAction", "void)__attribute__((ibaction)");
904     Builder.defineMacro("IBInspectable", "");
905     Builder.defineMacro("IB_DESIGNABLE", "");
906   }
907 
908   // Define a macro that describes the Objective-C boolean type even for C
909   // and C++ since BOOL can be used from non Objective-C code.
910   Builder.defineMacro("__OBJC_BOOL_IS_BOOL",
911                       Twine(TI.useSignedCharForObjCBool() ? "0" : "1"));
912 
913   if (LangOpts.CPlusPlus)
914     InitializeCPlusPlusFeatureTestMacros(LangOpts, Builder);
915 
916   // darwin_constant_cfstrings controls this. This is also dependent
917   // on other things like the runtime I believe.  This is set even for C code.
918   if (!LangOpts.NoConstantCFStrings)
919       Builder.defineMacro("__CONSTANT_CFSTRINGS__");
920 
921   if (LangOpts.ObjC)
922     Builder.defineMacro("OBJC_NEW_PROPERTIES");
923 
924   if (LangOpts.PascalStrings)
925     Builder.defineMacro("__PASCAL_STRINGS__");
926 
927   if (LangOpts.Blocks) {
928     Builder.defineMacro("__block", "__attribute__((__blocks__(byref)))");
929     Builder.defineMacro("__BLOCKS__");
930   }
931 
932   if (!LangOpts.MSVCCompat && LangOpts.Exceptions)
933     Builder.defineMacro("__EXCEPTIONS");
934   if (LangOpts.GNUCVersion && LangOpts.RTTI)
935     Builder.defineMacro("__GXX_RTTI");
936 
937   if (LangOpts.hasSjLjExceptions())
938     Builder.defineMacro("__USING_SJLJ_EXCEPTIONS__");
939   else if (LangOpts.hasSEHExceptions())
940     Builder.defineMacro("__SEH__");
941   else if (LangOpts.hasDWARFExceptions() &&
942            (TI.getTriple().isThumb() || TI.getTriple().isARM()))
943     Builder.defineMacro("__ARM_DWARF_EH__");
944 
945   if (LangOpts.Deprecated)
946     Builder.defineMacro("__DEPRECATED");
947 
948   if (!LangOpts.MSVCCompat && LangOpts.CPlusPlus)
949     Builder.defineMacro("__private_extern__", "extern");
950 
951   if (LangOpts.MicrosoftExt) {
952     if (LangOpts.WChar) {
953       // wchar_t supported as a keyword.
954       Builder.defineMacro("_WCHAR_T_DEFINED");
955       Builder.defineMacro("_NATIVE_WCHAR_T_DEFINED");
956     }
957   }
958 
959   // Macros to help identify the narrow and wide character sets
960   // FIXME: clang currently ignores -fexec-charset=. If this changes,
961   // then this may need to be updated.
962   Builder.defineMacro("__clang_literal_encoding__", "\"UTF-8\"");
963   if (TI.getTypeWidth(TI.getWCharType()) >= 32) {
964     // FIXME: 32-bit wchar_t signals UTF-32. This may change
965     // if -fwide-exec-charset= is ever supported.
966     Builder.defineMacro("__clang_wide_literal_encoding__", "\"UTF-32\"");
967   } else {
968     // FIXME: Less-than 32-bit wchar_t generally means UTF-16
969     // (e.g., Windows, 32-bit IBM). This may need to be
970     // updated if -fwide-exec-charset= is ever supported.
971     Builder.defineMacro("__clang_wide_literal_encoding__", "\"UTF-16\"");
972   }
973 
974   if (LangOpts.Optimize)
975     Builder.defineMacro("__OPTIMIZE__");
976   if (LangOpts.OptimizeSize)
977     Builder.defineMacro("__OPTIMIZE_SIZE__");
978 
979   if (LangOpts.FastMath)
980     Builder.defineMacro("__FAST_MATH__");
981 
982   // Initialize target-specific preprocessor defines.
983 
984   // __BYTE_ORDER__ was added in GCC 4.6. It's analogous
985   // to the macro __BYTE_ORDER (no trailing underscores)
986   // from glibc's <endian.h> header.
987   // We don't support the PDP-11 as a target, but include
988   // the define so it can still be compared against.
989   Builder.defineMacro("__ORDER_LITTLE_ENDIAN__", "1234");
990   Builder.defineMacro("__ORDER_BIG_ENDIAN__",    "4321");
991   Builder.defineMacro("__ORDER_PDP_ENDIAN__",    "3412");
992   if (TI.isBigEndian()) {
993     Builder.defineMacro("__BYTE_ORDER__", "__ORDER_BIG_ENDIAN__");
994     Builder.defineMacro("__BIG_ENDIAN__");
995   } else {
996     Builder.defineMacro("__BYTE_ORDER__", "__ORDER_LITTLE_ENDIAN__");
997     Builder.defineMacro("__LITTLE_ENDIAN__");
998   }
999 
1000   if (TI.getPointerWidth(LangAS::Default) == 64 && TI.getLongWidth() == 64 &&
1001       TI.getIntWidth() == 32) {
1002     Builder.defineMacro("_LP64");
1003     Builder.defineMacro("__LP64__");
1004   }
1005 
1006   if (TI.getPointerWidth(LangAS::Default) == 32 && TI.getLongWidth() == 32 &&
1007       TI.getIntWidth() == 32) {
1008     Builder.defineMacro("_ILP32");
1009     Builder.defineMacro("__ILP32__");
1010   }
1011 
1012   // Define type sizing macros based on the target properties.
1013   assert(TI.getCharWidth() == 8 && "Only support 8-bit char so far");
1014   Builder.defineMacro("__CHAR_BIT__", Twine(TI.getCharWidth()));
1015 
1016   Builder.defineMacro("__BOOL_WIDTH__", Twine(TI.getBoolWidth()));
1017   Builder.defineMacro("__SHRT_WIDTH__", Twine(TI.getShortWidth()));
1018   Builder.defineMacro("__INT_WIDTH__", Twine(TI.getIntWidth()));
1019   Builder.defineMacro("__LONG_WIDTH__", Twine(TI.getLongWidth()));
1020   Builder.defineMacro("__LLONG_WIDTH__", Twine(TI.getLongLongWidth()));
1021 
1022   size_t BitIntMaxWidth = TI.getMaxBitIntWidth();
1023   assert(BitIntMaxWidth <= llvm::IntegerType::MAX_INT_BITS &&
1024          "Target defined a max bit width larger than LLVM can support!");
1025   assert(BitIntMaxWidth >= TI.getLongLongWidth() &&
1026          "Target defined a max bit width smaller than the C standard allows!");
1027   Builder.defineMacro("__BITINT_MAXWIDTH__", Twine(BitIntMaxWidth));
1028 
1029   DefineTypeSize("__SCHAR_MAX__", TargetInfo::SignedChar, TI, Builder);
1030   DefineTypeSize("__SHRT_MAX__", TargetInfo::SignedShort, TI, Builder);
1031   DefineTypeSize("__INT_MAX__", TargetInfo::SignedInt, TI, Builder);
1032   DefineTypeSize("__LONG_MAX__", TargetInfo::SignedLong, TI, Builder);
1033   DefineTypeSize("__LONG_LONG_MAX__", TargetInfo::SignedLongLong, TI, Builder);
1034   DefineTypeSizeAndWidth("__WCHAR", TI.getWCharType(), TI, Builder);
1035   DefineTypeSizeAndWidth("__WINT", TI.getWIntType(), TI, Builder);
1036   DefineTypeSizeAndWidth("__INTMAX", TI.getIntMaxType(), TI, Builder);
1037   DefineTypeSizeAndWidth("__SIZE", TI.getSizeType(), TI, Builder);
1038 
1039   DefineTypeSizeAndWidth("__UINTMAX", TI.getUIntMaxType(), TI, Builder);
1040   DefineTypeSizeAndWidth("__PTRDIFF", TI.getPtrDiffType(LangAS::Default), TI,
1041                          Builder);
1042   DefineTypeSizeAndWidth("__INTPTR", TI.getIntPtrType(), TI, Builder);
1043   DefineTypeSizeAndWidth("__UINTPTR", TI.getUIntPtrType(), TI, Builder);
1044 
1045   DefineTypeSizeof("__SIZEOF_DOUBLE__", TI.getDoubleWidth(), TI, Builder);
1046   DefineTypeSizeof("__SIZEOF_FLOAT__", TI.getFloatWidth(), TI, Builder);
1047   DefineTypeSizeof("__SIZEOF_INT__", TI.getIntWidth(), TI, Builder);
1048   DefineTypeSizeof("__SIZEOF_LONG__", TI.getLongWidth(), TI, Builder);
1049   DefineTypeSizeof("__SIZEOF_LONG_DOUBLE__",TI.getLongDoubleWidth(),TI,Builder);
1050   DefineTypeSizeof("__SIZEOF_LONG_LONG__", TI.getLongLongWidth(), TI, Builder);
1051   DefineTypeSizeof("__SIZEOF_POINTER__", TI.getPointerWidth(LangAS::Default),
1052                    TI, Builder);
1053   DefineTypeSizeof("__SIZEOF_SHORT__", TI.getShortWidth(), TI, Builder);
1054   DefineTypeSizeof("__SIZEOF_PTRDIFF_T__",
1055                    TI.getTypeWidth(TI.getPtrDiffType(LangAS::Default)), TI,
1056                    Builder);
1057   DefineTypeSizeof("__SIZEOF_SIZE_T__",
1058                    TI.getTypeWidth(TI.getSizeType()), TI, Builder);
1059   DefineTypeSizeof("__SIZEOF_WCHAR_T__",
1060                    TI.getTypeWidth(TI.getWCharType()), TI, Builder);
1061   DefineTypeSizeof("__SIZEOF_WINT_T__",
1062                    TI.getTypeWidth(TI.getWIntType()), TI, Builder);
1063   if (TI.hasInt128Type())
1064     DefineTypeSizeof("__SIZEOF_INT128__", 128, TI, Builder);
1065 
1066   DefineType("__INTMAX_TYPE__", TI.getIntMaxType(), Builder);
1067   DefineFmt("__INTMAX", TI.getIntMaxType(), TI, Builder);
1068   Builder.defineMacro("__INTMAX_C_SUFFIX__",
1069                       TI.getTypeConstantSuffix(TI.getIntMaxType()));
1070   DefineType("__UINTMAX_TYPE__", TI.getUIntMaxType(), Builder);
1071   DefineFmt("__UINTMAX", TI.getUIntMaxType(), TI, Builder);
1072   Builder.defineMacro("__UINTMAX_C_SUFFIX__",
1073                       TI.getTypeConstantSuffix(TI.getUIntMaxType()));
1074   DefineType("__PTRDIFF_TYPE__", TI.getPtrDiffType(LangAS::Default), Builder);
1075   DefineFmt("__PTRDIFF", TI.getPtrDiffType(LangAS::Default), TI, Builder);
1076   DefineType("__INTPTR_TYPE__", TI.getIntPtrType(), Builder);
1077   DefineFmt("__INTPTR", TI.getIntPtrType(), TI, Builder);
1078   DefineType("__SIZE_TYPE__", TI.getSizeType(), Builder);
1079   DefineFmt("__SIZE", TI.getSizeType(), TI, Builder);
1080   DefineType("__WCHAR_TYPE__", TI.getWCharType(), Builder);
1081   DefineType("__WINT_TYPE__", TI.getWIntType(), Builder);
1082   DefineTypeSizeAndWidth("__SIG_ATOMIC", TI.getSigAtomicType(), TI, Builder);
1083   DefineType("__CHAR16_TYPE__", TI.getChar16Type(), Builder);
1084   DefineType("__CHAR32_TYPE__", TI.getChar32Type(), Builder);
1085 
1086   DefineType("__UINTPTR_TYPE__", TI.getUIntPtrType(), Builder);
1087   DefineFmt("__UINTPTR", TI.getUIntPtrType(), TI, Builder);
1088 
1089   // The C standard requires the width of uintptr_t and intptr_t to be the same,
1090   // per 7.20.2.4p1. Same for intmax_t and uintmax_t, per 7.20.2.5p1.
1091   assert(TI.getTypeWidth(TI.getUIntPtrType()) ==
1092              TI.getTypeWidth(TI.getIntPtrType()) &&
1093          "uintptr_t and intptr_t have different widths?");
1094   assert(TI.getTypeWidth(TI.getUIntMaxType()) ==
1095              TI.getTypeWidth(TI.getIntMaxType()) &&
1096          "uintmax_t and intmax_t have different widths?");
1097 
1098   if (TI.hasFloat16Type())
1099     DefineFloatMacros(Builder, "FLT16", &TI.getHalfFormat(), "F16");
1100   DefineFloatMacros(Builder, "FLT", &TI.getFloatFormat(), "F");
1101   DefineFloatMacros(Builder, "DBL", &TI.getDoubleFormat(), "");
1102   DefineFloatMacros(Builder, "LDBL", &TI.getLongDoubleFormat(), "L");
1103 
1104   // Define a __POINTER_WIDTH__ macro for stdint.h.
1105   Builder.defineMacro("__POINTER_WIDTH__",
1106                       Twine((int)TI.getPointerWidth(LangAS::Default)));
1107 
1108   // Define __BIGGEST_ALIGNMENT__ to be compatible with gcc.
1109   Builder.defineMacro("__BIGGEST_ALIGNMENT__",
1110                       Twine(TI.getSuitableAlign() / TI.getCharWidth()) );
1111 
1112   if (!LangOpts.CharIsSigned)
1113     Builder.defineMacro("__CHAR_UNSIGNED__");
1114 
1115   if (!TargetInfo::isTypeSigned(TI.getWCharType()))
1116     Builder.defineMacro("__WCHAR_UNSIGNED__");
1117 
1118   if (!TargetInfo::isTypeSigned(TI.getWIntType()))
1119     Builder.defineMacro("__WINT_UNSIGNED__");
1120 
1121   // Define exact-width integer types for stdint.h
1122   DefineExactWidthIntType(TargetInfo::SignedChar, TI, Builder);
1123 
1124   if (TI.getShortWidth() > TI.getCharWidth())
1125     DefineExactWidthIntType(TargetInfo::SignedShort, TI, Builder);
1126 
1127   if (TI.getIntWidth() > TI.getShortWidth())
1128     DefineExactWidthIntType(TargetInfo::SignedInt, TI, Builder);
1129 
1130   if (TI.getLongWidth() > TI.getIntWidth())
1131     DefineExactWidthIntType(TargetInfo::SignedLong, TI, Builder);
1132 
1133   if (TI.getLongLongWidth() > TI.getLongWidth())
1134     DefineExactWidthIntType(TargetInfo::SignedLongLong, TI, Builder);
1135 
1136   DefineExactWidthIntType(TargetInfo::UnsignedChar, TI, Builder);
1137   DefineExactWidthIntTypeSize(TargetInfo::UnsignedChar, TI, Builder);
1138   DefineExactWidthIntTypeSize(TargetInfo::SignedChar, TI, Builder);
1139 
1140   if (TI.getShortWidth() > TI.getCharWidth()) {
1141     DefineExactWidthIntType(TargetInfo::UnsignedShort, TI, Builder);
1142     DefineExactWidthIntTypeSize(TargetInfo::UnsignedShort, TI, Builder);
1143     DefineExactWidthIntTypeSize(TargetInfo::SignedShort, TI, Builder);
1144   }
1145 
1146   if (TI.getIntWidth() > TI.getShortWidth()) {
1147     DefineExactWidthIntType(TargetInfo::UnsignedInt, TI, Builder);
1148     DefineExactWidthIntTypeSize(TargetInfo::UnsignedInt, TI, Builder);
1149     DefineExactWidthIntTypeSize(TargetInfo::SignedInt, TI, Builder);
1150   }
1151 
1152   if (TI.getLongWidth() > TI.getIntWidth()) {
1153     DefineExactWidthIntType(TargetInfo::UnsignedLong, TI, Builder);
1154     DefineExactWidthIntTypeSize(TargetInfo::UnsignedLong, TI, Builder);
1155     DefineExactWidthIntTypeSize(TargetInfo::SignedLong, TI, Builder);
1156   }
1157 
1158   if (TI.getLongLongWidth() > TI.getLongWidth()) {
1159     DefineExactWidthIntType(TargetInfo::UnsignedLongLong, TI, Builder);
1160     DefineExactWidthIntTypeSize(TargetInfo::UnsignedLongLong, TI, Builder);
1161     DefineExactWidthIntTypeSize(TargetInfo::SignedLongLong, TI, Builder);
1162   }
1163 
1164   DefineLeastWidthIntType(8, true, TI, Builder);
1165   DefineLeastWidthIntType(8, false, TI, Builder);
1166   DefineLeastWidthIntType(16, true, TI, Builder);
1167   DefineLeastWidthIntType(16, false, TI, Builder);
1168   DefineLeastWidthIntType(32, true, TI, Builder);
1169   DefineLeastWidthIntType(32, false, TI, Builder);
1170   DefineLeastWidthIntType(64, true, TI, Builder);
1171   DefineLeastWidthIntType(64, false, TI, Builder);
1172 
1173   DefineFastIntType(8, true, TI, Builder);
1174   DefineFastIntType(8, false, TI, Builder);
1175   DefineFastIntType(16, true, TI, Builder);
1176   DefineFastIntType(16, false, TI, Builder);
1177   DefineFastIntType(32, true, TI, Builder);
1178   DefineFastIntType(32, false, TI, Builder);
1179   DefineFastIntType(64, true, TI, Builder);
1180   DefineFastIntType(64, false, TI, Builder);
1181 
1182   Builder.defineMacro("__USER_LABEL_PREFIX__", TI.getUserLabelPrefix());
1183 
1184   if (!LangOpts.MathErrno)
1185     Builder.defineMacro("__NO_MATH_ERRNO__");
1186 
1187   if (LangOpts.FastMath || LangOpts.FiniteMathOnly)
1188     Builder.defineMacro("__FINITE_MATH_ONLY__", "1");
1189   else
1190     Builder.defineMacro("__FINITE_MATH_ONLY__", "0");
1191 
1192   if (LangOpts.GNUCVersion) {
1193     if (LangOpts.GNUInline || LangOpts.CPlusPlus)
1194       Builder.defineMacro("__GNUC_GNU_INLINE__");
1195     else
1196       Builder.defineMacro("__GNUC_STDC_INLINE__");
1197 
1198     // The value written by __atomic_test_and_set.
1199     // FIXME: This is target-dependent.
1200     Builder.defineMacro("__GCC_ATOMIC_TEST_AND_SET_TRUEVAL", "1");
1201   }
1202 
1203   auto addLockFreeMacros = [&](const llvm::Twine &Prefix) {
1204     // Used by libc++ and libstdc++ to implement ATOMIC_<foo>_LOCK_FREE.
1205 #define DEFINE_LOCK_FREE_MACRO(TYPE, Type)                                     \
1206   Builder.defineMacro(Prefix + #TYPE "_LOCK_FREE",                             \
1207                       getLockFreeValue(TI.get##Type##Width(), TI));
1208     DEFINE_LOCK_FREE_MACRO(BOOL, Bool);
1209     DEFINE_LOCK_FREE_MACRO(CHAR, Char);
1210     if (LangOpts.Char8)
1211       DEFINE_LOCK_FREE_MACRO(CHAR8_T, Char); // Treat char8_t like char.
1212     DEFINE_LOCK_FREE_MACRO(CHAR16_T, Char16);
1213     DEFINE_LOCK_FREE_MACRO(CHAR32_T, Char32);
1214     DEFINE_LOCK_FREE_MACRO(WCHAR_T, WChar);
1215     DEFINE_LOCK_FREE_MACRO(SHORT, Short);
1216     DEFINE_LOCK_FREE_MACRO(INT, Int);
1217     DEFINE_LOCK_FREE_MACRO(LONG, Long);
1218     DEFINE_LOCK_FREE_MACRO(LLONG, LongLong);
1219     Builder.defineMacro(
1220         Prefix + "POINTER_LOCK_FREE",
1221         getLockFreeValue(TI.getPointerWidth(LangAS::Default), TI));
1222 #undef DEFINE_LOCK_FREE_MACRO
1223   };
1224   addLockFreeMacros("__CLANG_ATOMIC_");
1225   if (LangOpts.GNUCVersion)
1226     addLockFreeMacros("__GCC_ATOMIC_");
1227 
1228   if (LangOpts.NoInlineDefine)
1229     Builder.defineMacro("__NO_INLINE__");
1230 
1231   if (unsigned PICLevel = LangOpts.PICLevel) {
1232     Builder.defineMacro("__PIC__", Twine(PICLevel));
1233     Builder.defineMacro("__pic__", Twine(PICLevel));
1234     if (LangOpts.PIE) {
1235       Builder.defineMacro("__PIE__", Twine(PICLevel));
1236       Builder.defineMacro("__pie__", Twine(PICLevel));
1237     }
1238   }
1239 
1240   // Macros to control C99 numerics and <float.h>
1241   Builder.defineMacro("__FLT_RADIX__", "2");
1242   Builder.defineMacro("__DECIMAL_DIG__", "__LDBL_DECIMAL_DIG__");
1243 
1244   if (LangOpts.getStackProtector() == LangOptions::SSPOn)
1245     Builder.defineMacro("__SSP__");
1246   else if (LangOpts.getStackProtector() == LangOptions::SSPStrong)
1247     Builder.defineMacro("__SSP_STRONG__", "2");
1248   else if (LangOpts.getStackProtector() == LangOptions::SSPReq)
1249     Builder.defineMacro("__SSP_ALL__", "3");
1250 
1251   if (PPOpts.SetUpStaticAnalyzer)
1252     Builder.defineMacro("__clang_analyzer__");
1253 
1254   if (LangOpts.FastRelaxedMath)
1255     Builder.defineMacro("__FAST_RELAXED_MATH__");
1256 
1257   if (FEOpts.ProgramAction == frontend::RewriteObjC ||
1258       LangOpts.getGC() != LangOptions::NonGC) {
1259     Builder.defineMacro("__weak", "__attribute__((objc_gc(weak)))");
1260     Builder.defineMacro("__strong", "__attribute__((objc_gc(strong)))");
1261     Builder.defineMacro("__autoreleasing", "");
1262     Builder.defineMacro("__unsafe_unretained", "");
1263   } else if (LangOpts.ObjC) {
1264     Builder.defineMacro("__weak", "__attribute__((objc_ownership(weak)))");
1265     Builder.defineMacro("__strong", "__attribute__((objc_ownership(strong)))");
1266     Builder.defineMacro("__autoreleasing",
1267                         "__attribute__((objc_ownership(autoreleasing)))");
1268     Builder.defineMacro("__unsafe_unretained",
1269                         "__attribute__((objc_ownership(none)))");
1270   }
1271 
1272   // On Darwin, there are __double_underscored variants of the type
1273   // nullability qualifiers.
1274   if (TI.getTriple().isOSDarwin()) {
1275     Builder.defineMacro("__nonnull", "_Nonnull");
1276     Builder.defineMacro("__null_unspecified", "_Null_unspecified");
1277     Builder.defineMacro("__nullable", "_Nullable");
1278   }
1279 
1280   // Add a macro to differentiate between regular iOS/tvOS/watchOS targets and
1281   // the corresponding simulator targets.
1282   if (TI.getTriple().isOSDarwin() && TI.getTriple().isSimulatorEnvironment())
1283     Builder.defineMacro("__APPLE_EMBEDDED_SIMULATOR__", "1");
1284 
1285   // OpenMP definition
1286   // OpenMP 2.2:
1287   //   In implementations that support a preprocessor, the _OPENMP
1288   //   macro name is defined to have the decimal value yyyymm where
1289   //   yyyy and mm are the year and the month designations of the
1290   //   version of the OpenMP API that the implementation support.
1291   if (!LangOpts.OpenMPSimd) {
1292     switch (LangOpts.OpenMP) {
1293     case 0:
1294       break;
1295     case 31:
1296       Builder.defineMacro("_OPENMP", "201107");
1297       break;
1298     case 40:
1299       Builder.defineMacro("_OPENMP", "201307");
1300       break;
1301     case 45:
1302       Builder.defineMacro("_OPENMP", "201511");
1303       break;
1304     case 50:
1305       Builder.defineMacro("_OPENMP", "201811");
1306       break;
1307     case 52:
1308       Builder.defineMacro("_OPENMP", "202111");
1309       break;
1310     default: // case 51:
1311       // Default version is OpenMP 5.1
1312       Builder.defineMacro("_OPENMP", "202011");
1313       break;
1314     }
1315   }
1316 
1317   // CUDA device path compilaton
1318   if (LangOpts.CUDAIsDevice && !LangOpts.HIP) {
1319     // The CUDA_ARCH value is set for the GPU target specified in the NVPTX
1320     // backend's target defines.
1321     Builder.defineMacro("__CUDA_ARCH__");
1322   }
1323 
1324   // We need to communicate this to our CUDA/HIP header wrapper, which in turn
1325   // informs the proper CUDA/HIP headers of this choice.
1326   if (LangOpts.GPUDeviceApproxTranscendentals)
1327     Builder.defineMacro("__CLANG_GPU_APPROX_TRANSCENDENTALS__");
1328 
1329   // Define a macro indicating that the source file is being compiled with a
1330   // SYCL device compiler which doesn't produce host binary.
1331   if (LangOpts.SYCLIsDevice) {
1332     Builder.defineMacro("__SYCL_DEVICE_ONLY__", "1");
1333   }
1334 
1335   // OpenCL definitions.
1336   if (LangOpts.OpenCL) {
1337     InitializeOpenCLFeatureTestMacros(TI, LangOpts, Builder);
1338 
1339     if (TI.getTriple().isSPIR() || TI.getTriple().isSPIRV())
1340       Builder.defineMacro("__IMAGE_SUPPORT__");
1341   }
1342 
1343   if (TI.hasInt128Type() && LangOpts.CPlusPlus && LangOpts.GNUMode) {
1344     // For each extended integer type, g++ defines a macro mapping the
1345     // index of the type (0 in this case) in some list of extended types
1346     // to the type.
1347     Builder.defineMacro("__GLIBCXX_TYPE_INT_N_0", "__int128");
1348     Builder.defineMacro("__GLIBCXX_BITSIZE_INT_N_0", "128");
1349   }
1350 
1351   // ELF targets define __ELF__
1352   if (TI.getTriple().isOSBinFormatELF())
1353     Builder.defineMacro("__ELF__");
1354 
1355   // Target OS macro definitions.
1356   if (PPOpts.DefineTargetOSMacros) {
1357     const llvm::Triple &Triple = TI.getTriple();
1358 #define TARGET_OS(Name, Predicate)                                             \
1359   Builder.defineMacro(#Name, (Predicate) ? "1" : "0");
1360 #include "clang/Basic/TargetOSMacros.def"
1361 #undef TARGET_OS
1362   }
1363 
1364   // Get other target #defines.
1365   TI.getTargetDefines(LangOpts, Builder);
1366 }
1367 
1368 static void InitializePGOProfileMacros(const CodeGenOptions &CodeGenOpts,
1369                                        MacroBuilder &Builder) {
1370   if (CodeGenOpts.hasProfileInstr())
1371     Builder.defineMacro("__LLVM_INSTR_PROFILE_GENERATE");
1372 
1373   if (CodeGenOpts.hasProfileIRUse() || CodeGenOpts.hasProfileClangUse())
1374     Builder.defineMacro("__LLVM_INSTR_PROFILE_USE");
1375 }
1376 
1377 /// InitializePreprocessor - Initialize the preprocessor getting it and the
1378 /// environment ready to process a single file.
1379 void clang::InitializePreprocessor(Preprocessor &PP,
1380                                    const PreprocessorOptions &InitOpts,
1381                                    const PCHContainerReader &PCHContainerRdr,
1382                                    const FrontendOptions &FEOpts,
1383                                    const CodeGenOptions &CodeGenOpts) {
1384   const LangOptions &LangOpts = PP.getLangOpts();
1385   std::string PredefineBuffer;
1386   PredefineBuffer.reserve(4080);
1387   llvm::raw_string_ostream Predefines(PredefineBuffer);
1388   MacroBuilder Builder(Predefines);
1389 
1390   // Emit line markers for various builtin sections of the file. The 3 here
1391   // marks <built-in> as being a system header, which suppresses warnings when
1392   // the same macro is defined multiple times.
1393   Builder.append("# 1 \"<built-in>\" 3");
1394 
1395   // Install things like __POWERPC__, __GNUC__, etc into the macro table.
1396   if (InitOpts.UsePredefines) {
1397     // FIXME: This will create multiple definitions for most of the predefined
1398     // macros. This is not the right way to handle this.
1399     if ((LangOpts.CUDA || LangOpts.OpenMPIsTargetDevice ||
1400          LangOpts.SYCLIsDevice) &&
1401         PP.getAuxTargetInfo())
1402       InitializePredefinedMacros(*PP.getAuxTargetInfo(), LangOpts, FEOpts,
1403                                  PP.getPreprocessorOpts(), Builder);
1404 
1405     InitializePredefinedMacros(PP.getTargetInfo(), LangOpts, FEOpts,
1406                                PP.getPreprocessorOpts(), Builder);
1407 
1408     // Install definitions to make Objective-C++ ARC work well with various
1409     // C++ Standard Library implementations.
1410     if (LangOpts.ObjC && LangOpts.CPlusPlus &&
1411         (LangOpts.ObjCAutoRefCount || LangOpts.ObjCWeak)) {
1412       switch (InitOpts.ObjCXXARCStandardLibrary) {
1413       case ARCXX_nolib:
1414       case ARCXX_libcxx:
1415         break;
1416 
1417       case ARCXX_libstdcxx:
1418         AddObjCXXARCLibstdcxxDefines(LangOpts, Builder);
1419         break;
1420       }
1421     }
1422   }
1423 
1424   // Even with predefines off, some macros are still predefined.
1425   // These should all be defined in the preprocessor according to the
1426   // current language configuration.
1427   InitializeStandardPredefinedMacros(PP.getTargetInfo(), PP.getLangOpts(),
1428                                      FEOpts, Builder);
1429 
1430   // The PGO instrumentation profile macros are driven by options
1431   // -fprofile[-instr]-generate/-fcs-profile-generate/-fprofile[-instr]-use,
1432   // hence they are not guarded by InitOpts.UsePredefines.
1433   InitializePGOProfileMacros(CodeGenOpts, Builder);
1434 
1435   // Add on the predefines from the driver.  Wrap in a #line directive to report
1436   // that they come from the command line.
1437   Builder.append("# 1 \"<command line>\" 1");
1438 
1439   // Process #define's and #undef's in the order they are given.
1440   for (unsigned i = 0, e = InitOpts.Macros.size(); i != e; ++i) {
1441     if (InitOpts.Macros[i].second)  // isUndef
1442       Builder.undefineMacro(InitOpts.Macros[i].first);
1443     else
1444       DefineBuiltinMacro(Builder, InitOpts.Macros[i].first,
1445                          PP.getDiagnostics());
1446   }
1447 
1448   // Exit the command line and go back to <built-in> (2 is LC_LEAVE).
1449   Builder.append("# 1 \"<built-in>\" 2");
1450 
1451   // If -imacros are specified, include them now.  These are processed before
1452   // any -include directives.
1453   for (unsigned i = 0, e = InitOpts.MacroIncludes.size(); i != e; ++i)
1454     AddImplicitIncludeMacros(Builder, InitOpts.MacroIncludes[i]);
1455 
1456   // Process -include-pch/-include-pth directives.
1457   if (!InitOpts.ImplicitPCHInclude.empty())
1458     AddImplicitIncludePCH(Builder, PP, PCHContainerRdr,
1459                           InitOpts.ImplicitPCHInclude);
1460 
1461   // Process -include directives.
1462   for (unsigned i = 0, e = InitOpts.Includes.size(); i != e; ++i) {
1463     const std::string &Path = InitOpts.Includes[i];
1464     AddImplicitInclude(Builder, Path);
1465   }
1466 
1467   // Instruct the preprocessor to skip the preamble.
1468   PP.setSkipMainFilePreamble(InitOpts.PrecompiledPreambleBytes.first,
1469                              InitOpts.PrecompiledPreambleBytes.second);
1470 
1471   // Copy PredefinedBuffer into the Preprocessor.
1472   PP.setPredefines(std::move(PredefineBuffer));
1473 }
1474