xref: /llvm-project/clang/lib/Frontend/InitPreprocessor.cpp (revision 66cb01313b5fb5f6e667b02a2a1f1a0a1f9ddf35)
1 //===--- InitPreprocessor.cpp - PP initialization code. ---------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file implements the clang::InitializePreprocessor function.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "clang/Frontend/InitPreprocessor.h"
15 #include "clang/Basic/TargetInfo.h"
16 #include "clang/Lex/Preprocessor.h"
17 #include "llvm/ADT/StringExtras.h"
18 #include "llvm/ADT/STLExtras.h"
19 #include "llvm/System/Path.h"
20 
21 namespace clang {
22 
23 // Append a #define line to Buf for Macro.  Macro should be of the form XXX,
24 // in which case we emit "#define XXX 1" or "XXX=Y z W" in which case we emit
25 // "#define XXX Y z W".  To get a #define with no value, use "XXX=".
26 static void DefineBuiltinMacro(std::vector<char> &Buf, const char *Macro,
27                                const char *Command = "#define ") {
28   Buf.insert(Buf.end(), Command, Command+strlen(Command));
29   if (const char *Equal = strchr(Macro, '=')) {
30     // Turn the = into ' '.
31     Buf.insert(Buf.end(), Macro, Equal);
32     Buf.push_back(' ');
33 
34     // Per GCC -D semantics, the macro ends at \n if it exists.
35     const char *End = strpbrk(Equal, "\n\r");
36     if (End) {
37       fprintf(stderr, "warning: macro '%s' contains embedded newline, text "
38               "after the newline is ignored.\n",
39               std::string(Macro, Equal).c_str());
40     } else {
41       End = Equal+strlen(Equal);
42     }
43 
44     Buf.insert(Buf.end(), Equal+1, End);
45   } else {
46     // Push "macroname 1".
47     Buf.insert(Buf.end(), Macro, Macro+strlen(Macro));
48     Buf.push_back(' ');
49     Buf.push_back('1');
50   }
51   Buf.push_back('\n');
52 }
53 
54 /// Add the quoted name of an implicit include file.
55 static void AddQuotedIncludePath(std::vector<char> &Buf,
56                                  const std::string &File) {
57   // Implicit include paths should be resolved relative to the current
58   // working directory first, and then use the regular header search
59   // mechanism. The proper way to handle this is to have the
60   // predefines buffer located at the current working directory, but
61   // it has not file entry. For now, workaround this by using an
62   // absolute path if we find the file here, and otherwise letting
63   // header search handle it.
64   llvm::sys::Path Path(File);
65   Path.makeAbsolute();
66   if (!Path.exists())
67     Path = File;
68 
69   // Escape double quotes etc.
70   Buf.push_back('"');
71   std::string EscapedFile = Lexer::Stringify(Path.toString());
72   Buf.insert(Buf.end(), EscapedFile.begin(), EscapedFile.end());
73   Buf.push_back('"');
74 }
75 
76 /// AddImplicitInclude - Add an implicit #include of the specified file to the
77 /// predefines buffer.
78 static void AddImplicitInclude(std::vector<char> &Buf,
79                                const std::string &File) {
80   const char *Inc = "#include ";
81   Buf.insert(Buf.end(), Inc, Inc+strlen(Inc));
82   AddQuotedIncludePath(Buf, File);
83   Buf.push_back('\n');
84 }
85 
86 static void AddImplicitIncludeMacros(std::vector<char> &Buf,
87                                      const std::string &File) {
88   const char *Inc = "#__include_macros ";
89   Buf.insert(Buf.end(), Inc, Inc+strlen(Inc));
90   AddQuotedIncludePath(Buf, File);
91   Buf.push_back('\n');
92   // Marker token to stop the __include_macros fetch loop.
93   const char *Marker = "##\n"; // ##?
94   Buf.insert(Buf.end(), Marker, Marker+strlen(Marker));
95 }
96 
97 /// AddImplicitIncludePTH - Add an implicit #include using the original file
98 ///  used to generate a PTH cache.
99 static void AddImplicitIncludePTH(std::vector<char> &Buf, Preprocessor &PP,
100   const std::string& ImplicitIncludePTH) {
101   PTHManager *P = PP.getPTHManager();
102   assert(P && "No PTHManager.");
103   const char *OriginalFile = P->getOriginalSourceFile();
104 
105   if (!OriginalFile) {
106     assert(!ImplicitIncludePTH.empty());
107     fprintf(stderr, "error: PTH file '%s' does not designate an original "
108             "source header file for -include-pth\n",
109             ImplicitIncludePTH.c_str());
110     exit (1);
111   }
112 
113   AddImplicitInclude(Buf, OriginalFile);
114 }
115 
116 /// PickFP - This is used to pick a value based on the FP semantics of the
117 /// specified FP model.
118 template <typename T>
119 static T PickFP(const llvm::fltSemantics *Sem, T IEEESingleVal,
120                 T IEEEDoubleVal, T X87DoubleExtendedVal, T PPCDoubleDoubleVal) {
121   if (Sem == &llvm::APFloat::IEEEsingle)
122     return IEEESingleVal;
123   if (Sem == &llvm::APFloat::IEEEdouble)
124     return IEEEDoubleVal;
125   if (Sem == &llvm::APFloat::x87DoubleExtended)
126     return X87DoubleExtendedVal;
127   assert(Sem == &llvm::APFloat::PPCDoubleDouble);
128   return PPCDoubleDoubleVal;
129 }
130 
131 static void DefineFloatMacros(std::vector<char> &Buf, const char *Prefix,
132                               const llvm::fltSemantics *Sem) {
133   const char *DenormMin, *Epsilon, *Max, *Min;
134   DenormMin = PickFP(Sem, "1.40129846e-45F", "4.9406564584124654e-324",
135                      "3.64519953188247460253e-4951L",
136                      "4.94065645841246544176568792868221e-324L");
137   int Digits = PickFP(Sem, 6, 15, 18, 31);
138   Epsilon = PickFP(Sem, "1.19209290e-7F", "2.2204460492503131e-16",
139                    "1.08420217248550443401e-19L",
140                    "4.94065645841246544176568792868221e-324L");
141   int HasInifinity = 1, HasQuietNaN = 1;
142   int MantissaDigits = PickFP(Sem, 24, 53, 64, 106);
143   int Min10Exp = PickFP(Sem, -37, -307, -4931, -291);
144   int Max10Exp = PickFP(Sem, 38, 308, 4932, 308);
145   int MinExp = PickFP(Sem, -125, -1021, -16381, -968);
146   int MaxExp = PickFP(Sem, 128, 1024, 16384, 1024);
147   Min = PickFP(Sem, "1.17549435e-38F", "2.2250738585072014e-308",
148                "3.36210314311209350626e-4932L",
149                "2.00416836000897277799610805135016e-292L");
150   Max = PickFP(Sem, "3.40282347e+38F", "1.7976931348623157e+308",
151                "1.18973149535723176502e+4932L",
152                "1.79769313486231580793728971405301e+308L");
153 
154   char MacroBuf[60];
155   sprintf(MacroBuf, "__%s_DENORM_MIN__=%s", Prefix, DenormMin);
156   DefineBuiltinMacro(Buf, MacroBuf);
157   sprintf(MacroBuf, "__%s_DIG__=%d", Prefix, Digits);
158   DefineBuiltinMacro(Buf, MacroBuf);
159   sprintf(MacroBuf, "__%s_EPSILON__=%s", Prefix, Epsilon);
160   DefineBuiltinMacro(Buf, MacroBuf);
161   sprintf(MacroBuf, "__%s_HAS_INFINITY__=%d", Prefix, HasInifinity);
162   DefineBuiltinMacro(Buf, MacroBuf);
163   sprintf(MacroBuf, "__%s_HAS_QUIET_NAN__=%d", Prefix, HasQuietNaN);
164   DefineBuiltinMacro(Buf, MacroBuf);
165   sprintf(MacroBuf, "__%s_MANT_DIG__=%d", Prefix, MantissaDigits);
166   DefineBuiltinMacro(Buf, MacroBuf);
167   sprintf(MacroBuf, "__%s_MAX_10_EXP__=%d", Prefix, Max10Exp);
168   DefineBuiltinMacro(Buf, MacroBuf);
169   sprintf(MacroBuf, "__%s_MAX_EXP__=%d", Prefix, MaxExp);
170   DefineBuiltinMacro(Buf, MacroBuf);
171   sprintf(MacroBuf, "__%s_MAX__=%s", Prefix, Max);
172   DefineBuiltinMacro(Buf, MacroBuf);
173   sprintf(MacroBuf, "__%s_MIN_10_EXP__=(%d)", Prefix, Min10Exp);
174   DefineBuiltinMacro(Buf, MacroBuf);
175   sprintf(MacroBuf, "__%s_MIN_EXP__=(%d)", Prefix, MinExp);
176   DefineBuiltinMacro(Buf, MacroBuf);
177   sprintf(MacroBuf, "__%s_MIN__=%s", Prefix, Min);
178   DefineBuiltinMacro(Buf, MacroBuf);
179   sprintf(MacroBuf, "__%s_HAS_DENORM__=1", Prefix);
180   DefineBuiltinMacro(Buf, MacroBuf);
181 }
182 
183 
184 /// DefineTypeSize - Emit a macro to the predefines buffer that declares a macro
185 /// named MacroName with the max value for a type with width 'TypeWidth' a
186 /// signedness of 'isSigned' and with a value suffix of 'ValSuffix' (e.g. LL).
187 static void DefineTypeSize(const char *MacroName, unsigned TypeWidth,
188                            const char *ValSuffix, bool isSigned,
189                            std::vector<char> &Buf) {
190   char MacroBuf[60];
191   long long MaxVal;
192   if (isSigned)
193     MaxVal = (1LL << (TypeWidth - 1)) - 1;
194   else
195     MaxVal = ~0LL >> (64-TypeWidth);
196 
197   sprintf(MacroBuf, "%s=%llu%s", MacroName, MaxVal, ValSuffix);
198   DefineBuiltinMacro(Buf, MacroBuf);
199 }
200 
201 static void DefineType(const char *MacroName, TargetInfo::IntType Ty,
202                        std::vector<char> &Buf) {
203   char MacroBuf[60];
204   sprintf(MacroBuf, "%s=%s", MacroName, TargetInfo::getTypeName(Ty));
205   DefineBuiltinMacro(Buf, MacroBuf);
206 }
207 
208 
209 static void InitializePredefinedMacros(const TargetInfo &TI,
210                                        const LangOptions &LangOpts,
211                                        std::vector<char> &Buf) {
212   char MacroBuf[60];
213   // Compiler version introspection macros.
214   DefineBuiltinMacro(Buf, "__llvm__=1");   // LLVM Backend
215   DefineBuiltinMacro(Buf, "__clang__=1");  // Clang Frontend
216 
217   // Currently claim to be compatible with GCC 4.2.1-5621.
218   DefineBuiltinMacro(Buf, "__APPLE_CC__=5621");
219   DefineBuiltinMacro(Buf, "__GNUC_MINOR__=2");
220   DefineBuiltinMacro(Buf, "__GNUC_PATCHLEVEL__=1");
221   DefineBuiltinMacro(Buf, "__GNUC__=4");
222   DefineBuiltinMacro(Buf, "__GXX_ABI_VERSION=1002");
223   DefineBuiltinMacro(Buf, "__VERSION__=\"4.2.1 Compatible Clang Compiler\"");
224 
225 
226   // Initialize language-specific preprocessor defines.
227 
228   // These should all be defined in the preprocessor according to the
229   // current language configuration.
230   if (!LangOpts.Microsoft)
231     DefineBuiltinMacro(Buf, "__STDC__=1");
232   if (LangOpts.AsmPreprocessor)
233     DefineBuiltinMacro(Buf, "__ASSEMBLER__=1");
234   if (LangOpts.C99 && !LangOpts.CPlusPlus)
235     DefineBuiltinMacro(Buf, "__STDC_VERSION__=199901L");
236   else if (0) // STDC94 ?
237     DefineBuiltinMacro(Buf, "__STDC_VERSION__=199409L");
238 
239   // Standard conforming mode?
240   if (!LangOpts.GNUMode)
241     DefineBuiltinMacro(Buf, "__STRICT_ANSI__=1");
242 
243   if (LangOpts.CPlusPlus0x)
244     DefineBuiltinMacro(Buf, "__GXX_EXPERIMENTAL_CXX0X__");
245 
246   if (LangOpts.Freestanding)
247     DefineBuiltinMacro(Buf, "__STDC_HOSTED__=0");
248   else
249     DefineBuiltinMacro(Buf, "__STDC_HOSTED__=1");
250 
251   if (LangOpts.ObjC1) {
252     DefineBuiltinMacro(Buf, "__OBJC__=1");
253     if (LangOpts.ObjCNonFragileABI) {
254       DefineBuiltinMacro(Buf, "__OBJC2__=1");
255       DefineBuiltinMacro(Buf, "OBJC_ZEROCOST_EXCEPTIONS=1");
256       DefineBuiltinMacro(Buf, "__EXCEPTIONS=1");
257     }
258 
259     if (LangOpts.getGCMode() != LangOptions::NonGC)
260       DefineBuiltinMacro(Buf, "__OBJC_GC__=1");
261 
262     if (LangOpts.NeXTRuntime)
263       DefineBuiltinMacro(Buf, "__NEXT_RUNTIME__=1");
264   }
265 
266   // darwin_constant_cfstrings controls this. This is also dependent
267   // on other things like the runtime I believe.  This is set even for C code.
268   DefineBuiltinMacro(Buf, "__CONSTANT_CFSTRINGS__=1");
269 
270   if (LangOpts.ObjC2)
271     DefineBuiltinMacro(Buf, "OBJC_NEW_PROPERTIES");
272 
273   if (LangOpts.PascalStrings)
274     DefineBuiltinMacro(Buf, "__PASCAL_STRINGS__");
275 
276   if (LangOpts.Blocks) {
277     DefineBuiltinMacro(Buf, "__block=__attribute__((__blocks__(byref)))");
278     DefineBuiltinMacro(Buf, "__BLOCKS__=1");
279   }
280 
281   if (LangOpts.CPlusPlus) {
282     DefineBuiltinMacro(Buf, "__DEPRECATED=1");
283     DefineBuiltinMacro(Buf, "__EXCEPTIONS=1");
284     DefineBuiltinMacro(Buf, "__GNUG__=4");
285     DefineBuiltinMacro(Buf, "__GXX_WEAK__=1");
286     DefineBuiltinMacro(Buf, "__cplusplus=1");
287     DefineBuiltinMacro(Buf, "__private_extern__=extern");
288   }
289 
290   // Filter out some microsoft extensions when trying to parse in ms-compat
291   // mode.
292   if (LangOpts.Microsoft) {
293     DefineBuiltinMacro(Buf, "_cdecl=__cdecl");
294     DefineBuiltinMacro(Buf, "__int8=__INT8_TYPE__");
295     DefineBuiltinMacro(Buf, "__int16=__INT16_TYPE__");
296     DefineBuiltinMacro(Buf, "__int32=__INT32_TYPE__");
297     DefineBuiltinMacro(Buf, "__int64=__INT64_TYPE__");
298   }
299 
300   if (LangOpts.Optimize)
301     DefineBuiltinMacro(Buf, "__OPTIMIZE__=1");
302   if (LangOpts.OptimizeSize)
303     DefineBuiltinMacro(Buf, "__OPTIMIZE_SIZE__=1");
304 
305   // Initialize target-specific preprocessor defines.
306 
307   // Define type sizing macros based on the target properties.
308   assert(TI.getCharWidth() == 8 && "Only support 8-bit char so far");
309   DefineBuiltinMacro(Buf, "__CHAR_BIT__=8");
310 
311   unsigned IntMaxWidth;
312   const char *IntMaxSuffix;
313   if (TI.getIntMaxType() == TargetInfo::SignedLongLong) {
314     IntMaxWidth = TI.getLongLongWidth();
315     IntMaxSuffix = "LL";
316   } else if (TI.getIntMaxType() == TargetInfo::SignedLong) {
317     IntMaxWidth = TI.getLongWidth();
318     IntMaxSuffix = "L";
319   } else {
320     assert(TI.getIntMaxType() == TargetInfo::SignedInt);
321     IntMaxWidth = TI.getIntWidth();
322     IntMaxSuffix = "";
323   }
324 
325   DefineTypeSize("__SCHAR_MAX__", TI.getCharWidth(), "", true, Buf);
326   DefineTypeSize("__SHRT_MAX__", TI.getShortWidth(), "", true, Buf);
327   DefineTypeSize("__INT_MAX__", TI.getIntWidth(), "", true, Buf);
328   DefineTypeSize("__LONG_MAX__", TI.getLongWidth(), "L", true, Buf);
329   DefineTypeSize("__LONG_LONG_MAX__", TI.getLongLongWidth(), "LL", true, Buf);
330   DefineTypeSize("__WCHAR_MAX__", TI.getWCharWidth(), "", true, Buf);
331   DefineTypeSize("__INTMAX_MAX__", IntMaxWidth, IntMaxSuffix, true, Buf);
332 
333   DefineType("__INTMAX_TYPE__", TI.getIntMaxType(), Buf);
334   DefineType("__UINTMAX_TYPE__", TI.getUIntMaxType(), Buf);
335   DefineType("__PTRDIFF_TYPE__", TI.getPtrDiffType(0), Buf);
336   DefineType("__INTPTR_TYPE__", TI.getIntPtrType(), Buf);
337   DefineType("__SIZE_TYPE__", TI.getSizeType(), Buf);
338   DefineType("__WCHAR_TYPE__", TI.getWCharType(), Buf);
339   // FIXME: TargetInfo hookize __WINT_TYPE__.
340   DefineBuiltinMacro(Buf, "__WINT_TYPE__=int");
341 
342   DefineFloatMacros(Buf, "FLT", &TI.getFloatFormat());
343   DefineFloatMacros(Buf, "DBL", &TI.getDoubleFormat());
344   DefineFloatMacros(Buf, "LDBL", &TI.getLongDoubleFormat());
345 
346   // Define a __POINTER_WIDTH__ macro for stdint.h.
347   sprintf(MacroBuf, "__POINTER_WIDTH__=%d", (int)TI.getPointerWidth(0));
348   DefineBuiltinMacro(Buf, MacroBuf);
349 
350   if (!TI.isCharSigned())
351     DefineBuiltinMacro(Buf, "__CHAR_UNSIGNED__");
352 
353   // Define fixed-sized integer types for stdint.h
354   assert(TI.getCharWidth() == 8 && "unsupported target types");
355   assert(TI.getShortWidth() == 16 && "unsupported target types");
356   DefineBuiltinMacro(Buf, "__INT8_TYPE__=char");
357   DefineBuiltinMacro(Buf, "__INT16_TYPE__=short");
358 
359   if (TI.getIntWidth() == 32)
360     DefineBuiltinMacro(Buf, "__INT32_TYPE__=int");
361   else {
362     assert(TI.getLongLongWidth() == 32 && "unsupported target types");
363     DefineBuiltinMacro(Buf, "__INT32_TYPE__=long long");
364   }
365 
366   // 16-bit targets doesn't necessarily have a 64-bit type.
367   if (TI.getLongLongWidth() == 64)
368     DefineBuiltinMacro(Buf, "__INT64_TYPE__=long long");
369 
370   // Add __builtin_va_list typedef.
371   {
372     const char *VAList = TI.getVAListDeclaration();
373     Buf.insert(Buf.end(), VAList, VAList+strlen(VAList));
374     Buf.push_back('\n');
375   }
376 
377   if (const char *Prefix = TI.getUserLabelPrefix()) {
378     sprintf(MacroBuf, "__USER_LABEL_PREFIX__=%s", Prefix);
379     DefineBuiltinMacro(Buf, MacroBuf);
380   }
381 
382   // Build configuration options.  FIXME: these should be controlled by
383   // command line options or something.
384   DefineBuiltinMacro(Buf, "__FINITE_MATH_ONLY__=0");
385 
386   if (LangOpts.Static)
387     DefineBuiltinMacro(Buf, "__STATIC__=1");
388   else
389     DefineBuiltinMacro(Buf, "__DYNAMIC__=1");
390 
391   if (LangOpts.GNUInline)
392     DefineBuiltinMacro(Buf, "__GNUC_GNU_INLINE__=1");
393   else
394     DefineBuiltinMacro(Buf, "__GNUC_STDC_INLINE__=1");
395 
396   if (LangOpts.NoInline)
397     DefineBuiltinMacro(Buf, "__NO_INLINE__=1");
398 
399   if (unsigned PICLevel = LangOpts.PICLevel) {
400     sprintf(MacroBuf, "__PIC__=%d", PICLevel);
401     DefineBuiltinMacro(Buf, MacroBuf);
402 
403     sprintf(MacroBuf, "__pic__=%d", PICLevel);
404     DefineBuiltinMacro(Buf, MacroBuf);
405   }
406 
407   // Macros to control C99 numerics and <float.h>
408   DefineBuiltinMacro(Buf, "__FLT_EVAL_METHOD__=0");
409   DefineBuiltinMacro(Buf, "__FLT_RADIX__=2");
410   sprintf(MacroBuf, "__DECIMAL_DIG__=%d",
411           PickFP(&TI.getLongDoubleFormat(), -1/*FIXME*/, 17, 21, 33));
412   DefineBuiltinMacro(Buf, MacroBuf);
413 
414   // Get other target #defines.
415   TI.getTargetDefines(LangOpts, Buf);
416 }
417 
418 /// InitializePreprocessor - Initialize the preprocessor getting it and the
419 /// environment ready to process a single file. This returns true on error.
420 ///
421 bool InitializePreprocessor(Preprocessor &PP,
422                             const std::string &InFile,
423                             const PreprocessorInitOptions& InitOpts) {
424   std::vector<char> PredefineBuffer;
425 
426   const char *LineDirective = "# 1 \"<built-in>\" 3\n";
427   PredefineBuffer.insert(PredefineBuffer.end(),
428                          LineDirective, LineDirective+strlen(LineDirective));
429 
430   // Install things like __POWERPC__, __GNUC__, etc into the macro table.
431   InitializePredefinedMacros(PP.getTargetInfo(), PP.getLangOptions(),
432                              PredefineBuffer);
433 
434   // Add on the predefines from the driver.  Wrap in a #line directive to report
435   // that they come from the command line.
436   LineDirective = "# 1 \"<command line>\" 1\n";
437   PredefineBuffer.insert(PredefineBuffer.end(),
438                          LineDirective, LineDirective+strlen(LineDirective));
439 
440   // Process #define's and #undef's in the order they are given.
441   for (PreprocessorInitOptions::macro_iterator I = InitOpts.macro_begin(),
442        E = InitOpts.macro_end(); I != E; ++I) {
443     if (I->second)  // isUndef
444       DefineBuiltinMacro(PredefineBuffer, I->first.c_str(), "#undef ");
445     else
446       DefineBuiltinMacro(PredefineBuffer, I->first.c_str());
447   }
448 
449   // If -imacros are specified, include them now.  These are processed before
450   // any -include directives.
451   for (PreprocessorInitOptions::imacro_iterator I = InitOpts.imacro_begin(),
452        E = InitOpts.imacro_end(); I != E; ++I)
453     AddImplicitIncludeMacros(PredefineBuffer, *I);
454 
455   // Process -include directives.
456   for (PreprocessorInitOptions::include_iterator I = InitOpts.include_begin(),
457        E = InitOpts.include_end(); I != E; ++I) {
458     if (I->second) // isPTH
459       AddImplicitIncludePTH(PredefineBuffer, PP, I->first);
460     else
461       AddImplicitInclude(PredefineBuffer, I->first);
462  }
463 
464   LineDirective = "# 2 \"<built-in>\" 2 3\n";
465   PredefineBuffer.insert(PredefineBuffer.end(),
466                          LineDirective, LineDirective+strlen(LineDirective));
467 
468   // Null terminate PredefinedBuffer and add it.
469   PredefineBuffer.push_back(0);
470   PP.setPredefines(&PredefineBuffer[0]);
471 
472   // Once we've read this, we're done.
473   return false;
474 }
475 
476 } // namespace clang
477