lib/Parse/DeclSpec.cpp

   1 //===--- SemaDeclSpec.cpp - Declaration Specifier Semantic Analysis -------===//
   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 semantic analysis for declaration specifiers.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "clang/Parse/DeclSpec.h"
  15 #include "clang/Parse/ParseDiagnostic.h"
  16 #include "clang/Lex/Preprocessor.h"
  17 #include "clang/Basic/LangOptions.h"
  18 #include "llvm/ADT/STLExtras.h"
  19 #include <cstring>
  20 using namespace clang;
  21
  22
  23 static DiagnosticBuilder Diag(Diagnostic &D, SourceLocation Loc,
  24                               SourceManager &SrcMgr, unsigned DiagID) {
  25   return D.Report(FullSourceLoc(Loc, SrcMgr), DiagID);
  26 }
  27
  28 /// DeclaratorChunk::getFunction - Return a DeclaratorChunk for a function.
  29 /// "TheDeclarator" is the declarator that this will be added to.
  30 DeclaratorChunk DeclaratorChunk::getFunction(bool hasProto, bool isVariadic,
  31                                              SourceLocation EllipsisLoc,
  32                                              ParamInfo *ArgInfo,
  33                                              unsigned NumArgs,
  34                                              unsigned TypeQuals,
  35                                              bool hasExceptionSpec,
  36                                              SourceLocation ThrowLoc,
  37                                              bool hasAnyExceptionSpec,
  38                                              ActionBase::TypeTy **Exceptions,
  39                                              SourceRange *ExceptionRanges,
  40                                              unsigned NumExceptions,
  41                                              SourceLocation Loc,
  42                                              Declarator &TheDeclarator) {
  43   DeclaratorChunk I;
  44   I.Kind                 = Function;
  45   I.Loc                  = Loc;
  46   I.Fun.hasPrototype     = hasProto;
  47   I.Fun.isVariadic       = isVariadic;
  48   I.Fun.EllipsisLoc      = EllipsisLoc.getRawEncoding();
  49   I.Fun.DeleteArgInfo    = false;
  50   I.Fun.TypeQuals        = TypeQuals;
  51   I.Fun.NumArgs          = NumArgs;
  52   I.Fun.ArgInfo          = 0;
  53   I.Fun.hasExceptionSpec = hasExceptionSpec;
  54   I.Fun.ThrowLoc         = ThrowLoc.getRawEncoding();
  55   I.Fun.hasAnyExceptionSpec = hasAnyExceptionSpec;
  56   I.Fun.NumExceptions    = NumExceptions;
  57   I.Fun.Exceptions       = 0;
  58
  59   // new[] an argument array if needed.
  60   if (NumArgs) {
  61     // If the 'InlineParams' in Declarator is unused and big enough, put our
  62     // parameter list there (in an effort to avoid new/delete traffic).  If it
  63     // is already used (consider a function returning a function pointer) or too
  64     // small (function taking too many arguments), go to the heap.
  65     if (!TheDeclarator.InlineParamsUsed &&
  66         NumArgs <= llvm::array_lengthof(TheDeclarator.InlineParams)) {
  67       I.Fun.ArgInfo = TheDeclarator.InlineParams;
  68       I.Fun.DeleteArgInfo = false;
  69       TheDeclarator.InlineParamsUsed = true;
  70     } else {
  71       I.Fun.ArgInfo = new DeclaratorChunk::ParamInfo[NumArgs];
  72       I.Fun.DeleteArgInfo = true;
  73     }
  74     memcpy(I.Fun.ArgInfo, ArgInfo, sizeof(ArgInfo[0])*NumArgs);
  75   }
  76   // new[] an exception array if needed
  77   if (NumExceptions) {
  78     I.Fun.Exceptions = new DeclaratorChunk::TypeAndRange[NumExceptions];
  79     for (unsigned i = 0; i != NumExceptions; ++i) {
  80       I.Fun.Exceptions[i].Ty = Exceptions[i];
  81       I.Fun.Exceptions[i].Range = ExceptionRanges[i];
  82     }
  83   }
  84   return I;
  85 }
  86
  87 /// getParsedSpecifiers - Return a bitmask of which flavors of specifiers this
  88 /// declaration specifier includes.
  89 ///
  90 unsigned DeclSpec::getParsedSpecifiers() const {
  91   unsigned Res = 0;
  92   if (StorageClassSpec != SCS_unspecified ||
  93       SCS_thread_specified)
  94     Res |= PQ_StorageClassSpecifier;
  95
  96   if (TypeQualifiers != TQ_unspecified)
  97     Res |= PQ_TypeQualifier;
  98
  99   if (hasTypeSpecifier())
 100     Res |= PQ_TypeSpecifier;
 101
 102   if (FS_inline_specified || FS_virtual_specified || FS_explicit_specified)
 103     Res |= PQ_FunctionSpecifier;
 104   return Res;
 105 }
 106
 107 const char *DeclSpec::getSpecifierName(DeclSpec::SCS S) {
 108   switch (S) {
 109   default: assert(0 && "Unknown typespec!");
 110   case DeclSpec::SCS_unspecified: return "unspecified";
 111   case DeclSpec::SCS_typedef:     return "typedef";
 112   case DeclSpec::SCS_extern:      return "extern";
 113   case DeclSpec::SCS_static:      return "static";
 114   case DeclSpec::SCS_auto:        return "auto";
 115   case DeclSpec::SCS_register:    return "register";
 116   case DeclSpec::SCS_private_extern: return "__private_extern__";
 117   case DeclSpec::SCS_mutable:     return "mutable";
 118   }
 119 }
 120
 121 bool DeclSpec::BadSpecifier(SCS S, const char *&PrevSpec) {
 122   PrevSpec = getSpecifierName(S);
 123   return true;
 124 }
 125
 126 bool DeclSpec::BadSpecifier(TSW W, const char *&PrevSpec) {
 127   switch (W) {
 128   case TSW_unspecified: PrevSpec = "unspecified"; break;
 129   case TSW_short:       PrevSpec = "short"; break;
 130   case TSW_long:        PrevSpec = "long"; break;
 131   case TSW_longlong:    PrevSpec = "long long"; break;
 132   }
 133   return true;
 134 }
 135
 136 bool DeclSpec::BadSpecifier(TSC C, const char *&PrevSpec) {
 137   switch (C) {
 138   case TSC_unspecified: PrevSpec = "unspecified"; break;
 139   case TSC_imaginary:   PrevSpec = "imaginary"; break;
 140   case TSC_complex:     PrevSpec = "complex"; break;
 141   }
 142   return true;
 143 }
 144
 145
 146 bool DeclSpec::BadSpecifier(TSS S, const char *&PrevSpec) {
 147   switch (S) {
 148   case TSS_unspecified: PrevSpec = "unspecified"; break;
 149   case TSS_signed:      PrevSpec = "signed"; break;
 150   case TSS_unsigned:    PrevSpec = "unsigned"; break;
 151   }
 152   return true;
 153 }
 154
 155 const char *DeclSpec::getSpecifierName(DeclSpec::TST T) {
 156   switch (T) {
 157   default: assert(0 && "Unknown typespec!");
 158   case DeclSpec::TST_unspecified: return "unspecified";
 159   case DeclSpec::TST_void:        return "void";
 160   case DeclSpec::TST_char:        return "char";
 161   case DeclSpec::TST_wchar:       return "wchar_t";
 162   case DeclSpec::TST_char16:      return "char16_t";
 163   case DeclSpec::TST_char32:      return "char32_t";
 164   case DeclSpec::TST_int:         return "int";
 165   case DeclSpec::TST_float:       return "float";
 166   case DeclSpec::TST_double:      return "double";
 167   case DeclSpec::TST_bool:        return "_Bool";
 168   case DeclSpec::TST_decimal32:   return "_Decimal32";
 169   case DeclSpec::TST_decimal64:   return "_Decimal64";
 170   case DeclSpec::TST_decimal128:  return "_Decimal128";
 171   case DeclSpec::TST_enum:        return "enum";
 172   case DeclSpec::TST_class:       return "class";
 173   case DeclSpec::TST_union:       return "union";
 174   case DeclSpec::TST_struct:      return "struct";
 175   case DeclSpec::TST_typename:    return "type-name";
 176   case DeclSpec::TST_typeofType:
 177   case DeclSpec::TST_typeofExpr:  return "typeof";
 178   case DeclSpec::TST_auto:       return "auto";
 179   }
 180 }
 181
 182 bool DeclSpec::BadSpecifier(TST T, const char *&PrevSpec) {
 183   PrevSpec = getSpecifierName(T);
 184   return true;
 185 }
 186
 187 bool DeclSpec::BadSpecifier(TQ T, const char *&PrevSpec) {
 188   switch (T) {
 189   case DeclSpec::TQ_unspecified: PrevSpec = "unspecified"; break;
 190   case DeclSpec::TQ_const:       PrevSpec = "const"; break;
 191   case DeclSpec::TQ_restrict:    PrevSpec = "restrict"; break;
 192   case DeclSpec::TQ_volatile:    PrevSpec = "volatile"; break;
 193   }
 194   return true;
 195 }
 196
 197 bool DeclSpec::SetStorageClassSpec(SCS S, SourceLocation Loc,
 198                                    const char *&PrevSpec) {
 199   if (StorageClassSpec != SCS_unspecified)
 200     return BadSpecifier((SCS)StorageClassSpec, PrevSpec);
 201   StorageClassSpec = S;
 202   StorageClassSpecLoc = Loc;
 203   assert((unsigned)S == StorageClassSpec && "SCS constants overflow bitfield");
 204   return false;
 205 }
 206
 207 bool DeclSpec::SetStorageClassSpecThread(SourceLocation Loc,
 208                                          const char *&PrevSpec) {
 209   if (SCS_thread_specified) {
 210     PrevSpec = "__thread";
 211     return true;
 212   }
 213   SCS_thread_specified = true;
 214   SCS_threadLoc = Loc;
 215   return false;
 216 }
 217
 218
 219 /// These methods set the specified attribute of the DeclSpec, but return true
 220 /// and ignore the request if invalid (e.g. "extern" then "auto" is
 221 /// specified).
 222 bool DeclSpec::SetTypeSpecWidth(TSW W, SourceLocation Loc,
 223                                 const char *&PrevSpec) {
 224   if (TypeSpecWidth != TSW_unspecified &&
 225       // Allow turning long -> long long.
 226       (W != TSW_longlong || TypeSpecWidth != TSW_long))
 227     return BadSpecifier((TSW)TypeSpecWidth, PrevSpec);
 228   TypeSpecWidth = W;
 229   TSWLoc = Loc;
 230   return false;
 231 }
 232
 233 bool DeclSpec::SetTypeSpecComplex(TSC C, SourceLocation Loc,
 234                                   const char *&PrevSpec) {
 235   if (TypeSpecComplex != TSC_unspecified)
 236     return BadSpecifier((TSC)TypeSpecComplex, PrevSpec);
 237   TypeSpecComplex = C;
 238   TSCLoc = Loc;
 239   return false;
 240 }
 241
 242 bool DeclSpec::SetTypeSpecSign(TSS S, SourceLocation Loc,
 243                                const char *&PrevSpec) {
 244   if (TypeSpecSign != TSS_unspecified)
 245     return BadSpecifier((TSS)TypeSpecSign, PrevSpec);
 246   TypeSpecSign = S;
 247   TSSLoc = Loc;
 248   return false;
 249 }
 250
 251 bool DeclSpec::SetTypeSpecType(TST T, SourceLocation Loc,
 252                                const char *&PrevSpec, void *Rep,
 253                                bool Owned) {
 254   if (TypeSpecType != TST_unspecified)
 255     return BadSpecifier((TST)TypeSpecType, PrevSpec);
 256   TypeSpecType = T;
 257   TypeRep = Rep;
 258   TSTLoc = Loc;
 259   TypeSpecOwned = Owned;
 260   return false;
 261 }
 262
 263 bool DeclSpec::SetTypeSpecError() {
 264   TypeSpecType = TST_error;
 265   TypeRep = 0;
 266   TSTLoc = SourceLocation();
 267   return false;
 268 }
 269
 270 bool DeclSpec::SetTypeQual(TQ T, SourceLocation Loc, const char *&PrevSpec,
 271                            const LangOptions &Lang) {
 272   // Duplicates turn into warnings pre-C99.
 273   if ((TypeQualifiers & T) && !Lang.C99)
 274     return BadSpecifier(T, PrevSpec);
 275   TypeQualifiers |= T;
 276
 277   switch (T) {
 278   default: assert(0 && "Unknown type qualifier!");
 279   case TQ_const:    TQ_constLoc = Loc; break;
 280   case TQ_restrict: TQ_restrictLoc = Loc; break;
 281   case TQ_volatile: TQ_volatileLoc = Loc; break;
 282   }
 283   return false;
 284 }
 285
 286 bool DeclSpec::SetFunctionSpecInline(SourceLocation Loc, const char *&PrevSpec){
 287   // 'inline inline' is ok.
 288   FS_inline_specified = true;
 289   FS_inlineLoc = Loc;
 290   return false;
 291 }
 292
 293 bool DeclSpec::SetFunctionSpecVirtual(SourceLocation Loc, const char *&PrevSpec){
 294   // 'virtual virtual' is ok.
 295   FS_virtual_specified = true;
 296   FS_virtualLoc = Loc;
 297   return false;
 298 }
 299
 300 bool DeclSpec::SetFunctionSpecExplicit(SourceLocation Loc, const char *&PrevSpec){
 301   // 'explicit explicit' is ok.
 302   FS_explicit_specified = true;
 303   FS_explicitLoc = Loc;
 304   return false;
 305 }
 306
 307 bool DeclSpec::SetFriendSpec(SourceLocation Loc, const char *&PrevSpec) {
 308   if (Friend_specified) {
 309     PrevSpec = "friend";
 310     return true;
 311   }
 312
 313   Friend_specified = true;
 314   FriendLoc = Loc;
 315   return false;
 316 }
 317
 318 /// Finish - This does final analysis of the declspec, rejecting things like
 319 /// "_Imaginary" (lacking an FP type).  This returns a diagnostic to issue or
 320 /// diag::NUM_DIAGNOSTICS if there is no error.  After calling this method,
 321 /// DeclSpec is guaranteed self-consistent, even if an error occurred.
 322 void DeclSpec::Finish(Diagnostic &D, Preprocessor &PP) {
 323   // Check the type specifier components first.
 324   SourceManager &SrcMgr = PP.getSourceManager();
 325
 326   // signed/unsigned are only valid with int/char/wchar_t.
 327   if (TypeSpecSign != TSS_unspecified) {
 328     if (TypeSpecType == TST_unspecified)
 329       TypeSpecType = TST_int; // unsigned -> unsigned int, signed -> signed int.
 330     else if (TypeSpecType != TST_int  &&
 331              TypeSpecType != TST_char && TypeSpecType != TST_wchar) {
 332       Diag(D, TSSLoc, SrcMgr, diag::err_invalid_sign_spec)
 333         << getSpecifierName((TST)TypeSpecType);
 334       // signed double -> double.
 335       TypeSpecSign = TSS_unspecified;
 336     }
 337   }
 338
 339   // Validate the width of the type.
 340   switch (TypeSpecWidth) {
 341   case TSW_unspecified: break;
 342   case TSW_short:    // short int
 343   case TSW_longlong: // long long int
 344     if (TypeSpecType == TST_unspecified)
 345       TypeSpecType = TST_int; // short -> short int, long long -> long long int.
 346     else if (TypeSpecType != TST_int) {
 347       Diag(D, TSWLoc, SrcMgr,
 348            TypeSpecWidth == TSW_short ? diag::err_invalid_short_spec
 349                                       : diag::err_invalid_longlong_spec)
 350         <<  getSpecifierName((TST)TypeSpecType);
 351       TypeSpecType = TST_int;
 352     }
 353     break;
 354   case TSW_long:  // long double, long int
 355     if (TypeSpecType == TST_unspecified)
 356       TypeSpecType = TST_int;  // long -> long int.
 357     else if (TypeSpecType != TST_int && TypeSpecType != TST_double) {
 358       Diag(D, TSWLoc, SrcMgr, diag::err_invalid_long_spec)
 359         << getSpecifierName((TST)TypeSpecType);
 360       TypeSpecType = TST_int;
 361     }
 362     break;
 363   }
 364
 365   // TODO: if the implementation does not implement _Complex or _Imaginary,
 366   // disallow their use.  Need information about the backend.
 367   if (TypeSpecComplex != TSC_unspecified) {
 368     if (TypeSpecType == TST_unspecified) {
 369       Diag(D, TSCLoc, SrcMgr, diag::ext_plain_complex)
 370         << CodeModificationHint::CreateInsertion(
 371                               PP.getLocForEndOfToken(getTypeSpecComplexLoc()),
 372                                                  " double");
 373       TypeSpecType = TST_double;   // _Complex -> _Complex double.
 374     } else if (TypeSpecType == TST_int || TypeSpecType == TST_char) {
 375       // Note that this intentionally doesn't include _Complex _Bool.
 376       Diag(D, TSTLoc, SrcMgr, diag::ext_integer_complex);
 377     } else if (TypeSpecType != TST_float && TypeSpecType != TST_double) {
 378       Diag(D, TSCLoc, SrcMgr, diag::err_invalid_complex_spec)
 379         << getSpecifierName((TST)TypeSpecType);
 380       TypeSpecComplex = TSC_unspecified;
 381     }
 382   }
 383
 384   // Okay, now we can infer the real type.
 385
 386   // TODO: return "auto function" and other bad things based on the real type.
 387
 388   // 'data definition has no type or storage class'?
 389 }
 390
 391 bool DeclSpec::isMissingDeclaratorOk() {
 392   TST tst = getTypeSpecType();
 393   return (tst == TST_union
 394        || tst == TST_struct
 395        || tst == TST_class
 396        || tst == TST_enum
 397           ) && getTypeRep() != 0 && StorageClassSpec != DeclSpec::SCS_typedef;
 398 }