ParseDecl.cpp revision 5a6ddbf295d2ea1c28cfb67d82db22f3893ede6f 
1//===--- ParseDecl.cpp - Declaration Parsing ------------------------------===//
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 Declaration portions of the Parser interfaces.
11//
12//===----------------------------------------------------------------------===//
13
14#include "clang/Parse/Parser.h"
15#include "clang/Parse/DeclSpec.h"
16#include "clang/Parse/Scope.h"
17#include "llvm/ADT/SmallSet.h"
18using namespace clang;
19
20//===----------------------------------------------------------------------===//
21// C99 6.7: Declarations.
22//===----------------------------------------------------------------------===//
23
24/// ParseTypeName
25///       type-name: [C99 6.7.6]
26///         specifier-qualifier-list abstract-declarator[opt]
27Parser::TypeTy *Parser::ParseTypeName() {
28  // Parse the common declaration-specifiers piece.
29  DeclSpec DS;
30  ParseSpecifierQualifierList(DS);
31
32  // Parse the abstract-declarator, if present.
33  Declarator DeclaratorInfo(DS, Declarator::TypeNameContext);
34  ParseDeclarator(DeclaratorInfo);
35
36  return Actions.ActOnTypeName(CurScope, DeclaratorInfo).Val;
37}
38
39/// ParseAttributes - Parse a non-empty attributes list.
40///
41/// [GNU] attributes:
42///         attribute
43///         attributes attribute
44///
45/// [GNU]  attribute:
46///          '__attribute__' '(' '(' attribute-list ')' ')'
47///
48/// [GNU]  attribute-list:
49///          attrib
50///          attribute_list ',' attrib
51///
52/// [GNU]  attrib:
53///          empty
54///          attrib-name
55///          attrib-name '(' identifier ')'
56///          attrib-name '(' identifier ',' nonempty-expr-list ')'
57///          attrib-name '(' argument-expression-list [C99 6.5.2] ')'
58///
59/// [GNU]  attrib-name:
60///          identifier
61///          typespec
62///          typequal
63///          storageclass
64///
65/// FIXME: The GCC grammar/code for this construct implies we need two
66/// token lookahead. Comment from gcc: "If they start with an identifier
67/// which is followed by a comma or close parenthesis, then the arguments
68/// start with that identifier; otherwise they are an expression list."
69///
70/// At the moment, I am not doing 2 token lookahead. I am also unaware of
71/// any attributes that don't work (based on my limited testing). Most
72/// attributes are very simple in practice. Until we find a bug, I don't see
73/// a pressing need to implement the 2 token lookahead.
74
75AttributeList *Parser::ParseAttributes() {
76  assert(Tok.is(tok::kw___attribute) && "Not an attribute list!");
77
78  AttributeList *CurrAttr = 0;
79
80  while (Tok.is(tok::kw___attribute)) {
81    ConsumeToken();
82    if (ExpectAndConsume(tok::l_paren, diag::err_expected_lparen_after,
83                         "attribute")) {
84      SkipUntil(tok::r_paren, true); // skip until ) or ;
85      return CurrAttr;
86    }
87    if (ExpectAndConsume(tok::l_paren, diag::err_expected_lparen_after, "(")) {
88      SkipUntil(tok::r_paren, true); // skip until ) or ;
89      return CurrAttr;
90    }
91    // Parse the attribute-list. e.g. __attribute__(( weak, alias("__f") ))
92    while (Tok.is(tok::identifier) || isDeclarationSpecifier() ||
93           Tok.is(tok::comma)) {
94
95      if (Tok.is(tok::comma)) {
96        // allows for empty/non-empty attributes. ((__vector_size__(16),,,,))
97        ConsumeToken();
98        continue;
99      }
100      // we have an identifier or declaration specifier (const, int, etc.)
101      IdentifierInfo *AttrName = Tok.getIdentifierInfo();
102      SourceLocation AttrNameLoc = ConsumeToken();
103
104      // check if we have a "paramterized" attribute
105      if (Tok.is(tok::l_paren)) {
106        ConsumeParen(); // ignore the left paren loc for now
107
108        if (Tok.is(tok::identifier)) {
109          IdentifierInfo *ParmName = Tok.getIdentifierInfo();
110          SourceLocation ParmLoc = ConsumeToken();
111
112          if (Tok.is(tok::r_paren)) {
113            // __attribute__(( mode(byte) ))
114            ConsumeParen(); // ignore the right paren loc for now
115            CurrAttr = new AttributeList(AttrName, AttrNameLoc,
116                                         ParmName, ParmLoc, 0, 0, CurrAttr);
117          } else if (Tok.is(tok::comma)) {
118            ConsumeToken();
119            // __attribute__(( format(printf, 1, 2) ))
120            llvm::SmallVector<ExprTy*, 8> ArgExprs;
121            bool ArgExprsOk = true;
122
123            // now parse the non-empty comma separated list of expressions
124            while (1) {
125              ExprResult ArgExpr = ParseAssignmentExpression();
126              if (ArgExpr.isInvalid) {
127                ArgExprsOk = false;
128                SkipUntil(tok::r_paren);
129                break;
130              } else {
131                ArgExprs.push_back(ArgExpr.Val);
132              }
133              if (Tok.isNot(tok::comma))
134                break;
135              ConsumeToken(); // Eat the comma, move to the next argument
136            }
137            if (ArgExprsOk && Tok.is(tok::r_paren)) {
138              ConsumeParen(); // ignore the right paren loc for now
139              CurrAttr = new AttributeList(AttrName, AttrNameLoc, ParmName,
140                           ParmLoc, &ArgExprs[0], ArgExprs.size(), CurrAttr);
141            }
142          }
143        } else { // not an identifier
144          // parse a possibly empty comma separated list of expressions
145          if (Tok.is(tok::r_paren)) {
146            // __attribute__(( nonnull() ))
147            ConsumeParen(); // ignore the right paren loc for now
148            CurrAttr = new AttributeList(AttrName, AttrNameLoc,
149                                         0, SourceLocation(), 0, 0, CurrAttr);
150          } else {
151            // __attribute__(( aligned(16) ))
152            llvm::SmallVector<ExprTy*, 8> ArgExprs;
153            bool ArgExprsOk = true;
154
155            // now parse the list of expressions
156            while (1) {
157              ExprResult ArgExpr = ParseAssignmentExpression();
158              if (ArgExpr.isInvalid) {
159                ArgExprsOk = false;
160                SkipUntil(tok::r_paren);
161                break;
162              } else {
163                ArgExprs.push_back(ArgExpr.Val);
164              }
165              if (Tok.isNot(tok::comma))
166                break;
167              ConsumeToken(); // Eat the comma, move to the next argument
168            }
169            // Match the ')'.
170            if (ArgExprsOk && Tok.is(tok::r_paren)) {
171              ConsumeParen(); // ignore the right paren loc for now
172              CurrAttr = new AttributeList(AttrName, AttrNameLoc, 0,
173                           SourceLocation(), &ArgExprs[0], ArgExprs.size(),
174                           CurrAttr);
175            }
176          }
177        }
178      } else {
179        CurrAttr = new AttributeList(AttrName, AttrNameLoc,
180                                     0, SourceLocation(), 0, 0, CurrAttr);
181      }
182    }
183    if (ExpectAndConsume(tok::r_paren, diag::err_expected_rparen))
184      SkipUntil(tok::r_paren, false);
185    if (ExpectAndConsume(tok::r_paren, diag::err_expected_rparen))
186      SkipUntil(tok::r_paren, false);
187  }
188  return CurrAttr;
189}
190
191/// ParseDeclaration - Parse a full 'declaration', which consists of
192/// declaration-specifiers, some number of declarators, and a semicolon.
193/// 'Context' should be a Declarator::TheContext value.
194///
195///       declaration: [C99 6.7]
196///         block-declaration ->
197///           simple-declaration
198///           others                   [FIXME]
199/// [C++]   namespace-definition
200///         others... [FIXME]
201///
202Parser::DeclTy *Parser::ParseDeclaration(unsigned Context) {
203  switch (Tok.getKind()) {
204  case tok::kw_namespace:
205    return ParseNamespace(Context);
206  default:
207    return ParseSimpleDeclaration(Context);
208  }
209}
210
211///       simple-declaration: [C99 6.7: declaration] [C++ 7p1: dcl.dcl]
212///         declaration-specifiers init-declarator-list[opt] ';'
213///[C90/C++]init-declarator-list ';'                             [TODO]
214/// [OMP]   threadprivate-directive                              [TODO]
215Parser::DeclTy *Parser::ParseSimpleDeclaration(unsigned Context) {
216  // Parse the common declaration-specifiers piece.
217  DeclSpec DS;
218  ParseDeclarationSpecifiers(DS);
219
220  // C99 6.7.2.3p6: Handle "struct-or-union identifier;", "enum { X };"
221  // declaration-specifiers init-declarator-list[opt] ';'
222  if (Tok.is(tok::semi)) {
223    ConsumeToken();
224    return Actions.ParsedFreeStandingDeclSpec(CurScope, DS);
225  }
226
227  Declarator DeclaratorInfo(DS, (Declarator::TheContext)Context);
228  ParseDeclarator(DeclaratorInfo);
229
230  return ParseInitDeclaratorListAfterFirstDeclarator(DeclaratorInfo);
231}
232
233
234/// ParseInitDeclaratorListAfterFirstDeclarator - Parse 'declaration' after
235/// parsing 'declaration-specifiers declarator'.  This method is split out this
236/// way to handle the ambiguity between top-level function-definitions and
237/// declarations.
238///
239///       init-declarator-list: [C99 6.7]
240///         init-declarator
241///         init-declarator-list ',' init-declarator
242///       init-declarator: [C99 6.7]
243///         declarator
244///         declarator '=' initializer
245/// [GNU]   declarator simple-asm-expr[opt] attributes[opt]
246/// [GNU]   declarator simple-asm-expr[opt] attributes[opt] '=' initializer
247///
248Parser::DeclTy *Parser::
249ParseInitDeclaratorListAfterFirstDeclarator(Declarator &D) {
250
251  // Declarators may be grouped together ("int X, *Y, Z();").  Provide info so
252  // that they can be chained properly if the actions want this.
253  Parser::DeclTy *LastDeclInGroup = 0;
254
255  // At this point, we know that it is not a function definition.  Parse the
256  // rest of the init-declarator-list.
257  while (1) {
258    // If a simple-asm-expr is present, parse it.
259    if (Tok.is(tok::kw_asm))
260      ParseSimpleAsm();
261
262    // If attributes are present, parse them.
263    if (Tok.is(tok::kw___attribute))
264      D.AddAttributes(ParseAttributes());
265
266    // Inform the current actions module that we just parsed this declarator.
267    // FIXME: pass asm & attributes.
268    LastDeclInGroup = Actions.ActOnDeclarator(CurScope, D, LastDeclInGroup);
269
270    // Parse declarator '=' initializer.
271    ExprResult Init;
272    if (Tok.is(tok::equal)) {
273      ConsumeToken();
274      Init = ParseInitializer();
275      if (Init.isInvalid) {
276        SkipUntil(tok::semi);
277        return 0;
278      }
279      Actions.AddInitializerToDecl(LastDeclInGroup, Init.Val);
280    }
281
282    // If we don't have a comma, it is either the end of the list (a ';') or an
283    // error, bail out.
284    if (Tok.isNot(tok::comma))
285      break;
286
287    // Consume the comma.
288    ConsumeToken();
289
290    // Parse the next declarator.
291    D.clear();
292    ParseDeclarator(D);
293  }
294
295  if (Tok.is(tok::semi)) {
296    ConsumeToken();
297    return Actions.FinalizeDeclaratorGroup(CurScope, LastDeclInGroup);
298  }
299  // If this is an ObjC2 for-each loop, this is a successful declarator
300  // parse.  The syntax for these looks like:
301  // 'for' '(' declaration 'in' expr ')' statement
302  if (D.getContext()  == Declarator::ForContext && isTokIdentifier_in()) {
303    return Actions.FinalizeDeclaratorGroup(CurScope, LastDeclInGroup);
304  }
305  Diag(Tok, diag::err_parse_error);
306  // Skip to end of block or statement
307  SkipUntil(tok::r_brace, true, true);
308  if (Tok.is(tok::semi))
309    ConsumeToken();
310  return 0;
311}
312
313/// ParseSpecifierQualifierList
314///        specifier-qualifier-list:
315///          type-specifier specifier-qualifier-list[opt]
316///          type-qualifier specifier-qualifier-list[opt]
317/// [GNU]    attributes     specifier-qualifier-list[opt]
318///
319void Parser::ParseSpecifierQualifierList(DeclSpec &DS) {
320  /// specifier-qualifier-list is a subset of declaration-specifiers.  Just
321  /// parse declaration-specifiers and complain about extra stuff.
322  ParseDeclarationSpecifiers(DS);
323
324  // Validate declspec for type-name.
325  unsigned Specs = DS.getParsedSpecifiers();
326  if (Specs == DeclSpec::PQ_None && !DS.getNumProtocolQualifiers())
327    Diag(Tok, diag::err_typename_requires_specqual);
328
329  // Issue diagnostic and remove storage class if present.
330  if (Specs & DeclSpec::PQ_StorageClassSpecifier) {
331    if (DS.getStorageClassSpecLoc().isValid())
332      Diag(DS.getStorageClassSpecLoc(),diag::err_typename_invalid_storageclass);
333    else
334      Diag(DS.getThreadSpecLoc(), diag::err_typename_invalid_storageclass);
335    DS.ClearStorageClassSpecs();
336  }
337
338  // Issue diagnostic and remove function specfier if present.
339  if (Specs & DeclSpec::PQ_FunctionSpecifier) {
340    Diag(DS.getInlineSpecLoc(), diag::err_typename_invalid_functionspec);
341    DS.ClearFunctionSpecs();
342  }
343}
344
345/// ParseDeclarationSpecifiers
346///       declaration-specifiers: [C99 6.7]
347///         storage-class-specifier declaration-specifiers[opt]
348///         type-specifier declaration-specifiers[opt]
349///         type-qualifier declaration-specifiers[opt]
350/// [C99]   function-specifier declaration-specifiers[opt]
351/// [GNU]   attributes declaration-specifiers[opt]
352///
353///       storage-class-specifier: [C99 6.7.1]
354///         'typedef'
355///         'extern'
356///         'static'
357///         'auto'
358///         'register'
359/// [GNU]   '__thread'
360///       type-specifier: [C99 6.7.2]
361///         'void'
362///         'char'
363///         'short'
364///         'int'
365///         'long'
366///         'float'
367///         'double'
368///         'signed'
369///         'unsigned'
370///         struct-or-union-specifier
371///         enum-specifier
372///         typedef-name
373/// [C++]   'bool'
374/// [C99]   '_Bool'
375/// [C99]   '_Complex'
376/// [C99]   '_Imaginary'  // Removed in TC2?
377/// [GNU]   '_Decimal32'
378/// [GNU]   '_Decimal64'
379/// [GNU]   '_Decimal128'
380/// [GNU]   typeof-specifier
381/// [OBJC]  class-name objc-protocol-refs[opt]    [TODO]
382/// [OBJC]  typedef-name objc-protocol-refs[opt]  [TODO]
383///       type-qualifier:
384///         'const'
385///         'volatile'
386/// [C99]   'restrict'
387///       function-specifier: [C99 6.7.4]
388/// [C99]   'inline'
389///
390void Parser::ParseDeclarationSpecifiers(DeclSpec &DS) {
391  DS.SetRangeStart(Tok.getLocation());
392  while (1) {
393    int isInvalid = false;
394    const char *PrevSpec = 0;
395    SourceLocation Loc = Tok.getLocation();
396
397    switch (Tok.getKind()) {
398      // typedef-name
399    case tok::identifier:
400      // This identifier can only be a typedef name if we haven't already seen
401      // a type-specifier.  Without this check we misparse:
402      //  typedef int X; struct Y { short X; };  as 'short int'.
403      if (!DS.hasTypeSpecifier()) {
404        // It has to be available as a typedef too!
405        if (void *TypeRep = Actions.isTypeName(*Tok.getIdentifierInfo(),
406                                               CurScope)) {
407          isInvalid = DS.SetTypeSpecType(DeclSpec::TST_typedef, Loc, PrevSpec,
408                                         TypeRep);
409          if (isInvalid)
410            break;
411          // FIXME: restrict this to "id" and ObjC classnames.
412          DS.SetRangeEnd(Tok.getLocation());
413          ConsumeToken(); // The identifier
414          if (Tok.is(tok::less)) {
415            SourceLocation endProtoLoc;
416            llvm::SmallVector<IdentifierInfo *, 8> ProtocolRefs;
417            ParseObjCProtocolReferences(ProtocolRefs, endProtoLoc);
418            llvm::SmallVector<DeclTy *, 8> *ProtocolDecl =
419                    new llvm::SmallVector<DeclTy *, 8>;
420            DS.setProtocolQualifiers(ProtocolDecl);
421            Actions.FindProtocolDeclaration(Loc,
422                      &ProtocolRefs[0], ProtocolRefs.size(),
423                      *ProtocolDecl);
424          }
425          continue;
426        }
427      }
428      // FALL THROUGH.
429    default:
430      // If this is not a declaration specifier token, we're done reading decl
431      // specifiers.  First verify that DeclSpec's are consistent.
432      DS.Finish(Diags, PP.getSourceManager(), getLang());
433      return;
434
435    // GNU attributes support.
436    case tok::kw___attribute:
437      DS.AddAttributes(ParseAttributes());
438      continue;
439
440    // storage-class-specifier
441    case tok::kw_typedef:
442      isInvalid = DS.SetStorageClassSpec(DeclSpec::SCS_typedef, Loc, PrevSpec);
443      break;
444    case tok::kw_extern:
445      if (DS.isThreadSpecified())
446        Diag(Tok, diag::ext_thread_before, "extern");
447      isInvalid = DS.SetStorageClassSpec(DeclSpec::SCS_extern, Loc, PrevSpec);
448      break;
449    case tok::kw___private_extern__:
450      isInvalid = DS.SetStorageClassSpec(DeclSpec::SCS_private_extern, Loc,
451                                         PrevSpec);
452      break;
453    case tok::kw_static:
454      if (DS.isThreadSpecified())
455        Diag(Tok, diag::ext_thread_before, "static");
456      isInvalid = DS.SetStorageClassSpec(DeclSpec::SCS_static, Loc, PrevSpec);
457      break;
458    case tok::kw_auto:
459      isInvalid = DS.SetStorageClassSpec(DeclSpec::SCS_auto, Loc, PrevSpec);
460      break;
461    case tok::kw_register:
462      isInvalid = DS.SetStorageClassSpec(DeclSpec::SCS_register, Loc, PrevSpec);
463      break;
464    case tok::kw___thread:
465      isInvalid = DS.SetStorageClassSpecThread(Loc, PrevSpec)*2;
466      break;
467
468    // type-specifiers
469    case tok::kw_short:
470      isInvalid = DS.SetTypeSpecWidth(DeclSpec::TSW_short, Loc, PrevSpec);
471      break;
472    case tok::kw_long:
473      if (DS.getTypeSpecWidth() != DeclSpec::TSW_long)
474        isInvalid = DS.SetTypeSpecWidth(DeclSpec::TSW_long, Loc, PrevSpec);
475      else
476        isInvalid = DS.SetTypeSpecWidth(DeclSpec::TSW_longlong, Loc, PrevSpec);
477      break;
478    case tok::kw_signed:
479      isInvalid = DS.SetTypeSpecSign(DeclSpec::TSS_signed, Loc, PrevSpec);
480      break;
481    case tok::kw_unsigned:
482      isInvalid = DS.SetTypeSpecSign(DeclSpec::TSS_unsigned, Loc, PrevSpec);
483      break;
484    case tok::kw__Complex:
485      isInvalid = DS.SetTypeSpecComplex(DeclSpec::TSC_complex, Loc, PrevSpec);
486      break;
487    case tok::kw__Imaginary:
488      isInvalid = DS.SetTypeSpecComplex(DeclSpec::TSC_imaginary, Loc, PrevSpec);
489      break;
490    case tok::kw_void:
491      isInvalid = DS.SetTypeSpecType(DeclSpec::TST_void, Loc, PrevSpec);
492      break;
493    case tok::kw_char:
494      isInvalid = DS.SetTypeSpecType(DeclSpec::TST_char, Loc, PrevSpec);
495      break;
496    case tok::kw_int:
497      isInvalid = DS.SetTypeSpecType(DeclSpec::TST_int, Loc, PrevSpec);
498      break;
499    case tok::kw_float:
500      isInvalid = DS.SetTypeSpecType(DeclSpec::TST_float, Loc, PrevSpec);
501      break;
502    case tok::kw_double:
503      isInvalid = DS.SetTypeSpecType(DeclSpec::TST_double, Loc, PrevSpec);
504      break;
505    case tok::kw_bool:          // [C++ 2.11p1]
506    case tok::kw__Bool:
507      isInvalid = DS.SetTypeSpecType(DeclSpec::TST_bool, Loc, PrevSpec);
508      break;
509    case tok::kw__Decimal32:
510      isInvalid = DS.SetTypeSpecType(DeclSpec::TST_decimal32, Loc, PrevSpec);
511      break;
512    case tok::kw__Decimal64:
513      isInvalid = DS.SetTypeSpecType(DeclSpec::TST_decimal64, Loc, PrevSpec);
514      break;
515    case tok::kw__Decimal128:
516      isInvalid = DS.SetTypeSpecType(DeclSpec::TST_decimal128, Loc, PrevSpec);
517      break;
518
519    case tok::kw_class:
520    case tok::kw_struct:
521    case tok::kw_union:
522      ParseClassSpecifier(DS);
523      continue;
524    case tok::kw_enum:
525      ParseEnumSpecifier(DS);
526      continue;
527
528    // GNU typeof support.
529    case tok::kw_typeof:
530      ParseTypeofSpecifier(DS);
531      continue;
532
533    // type-qualifier
534    case tok::kw_const:
535      isInvalid = DS.SetTypeQual(DeclSpec::TQ_const   , Loc, PrevSpec,
536                                 getLang())*2;
537      break;
538    case tok::kw_volatile:
539      isInvalid = DS.SetTypeQual(DeclSpec::TQ_volatile, Loc, PrevSpec,
540                                 getLang())*2;
541      break;
542    case tok::kw_restrict:
543      isInvalid = DS.SetTypeQual(DeclSpec::TQ_restrict, Loc, PrevSpec,
544                                 getLang())*2;
545      break;
546
547    // function-specifier
548    case tok::kw_inline:
549      isInvalid = DS.SetFunctionSpecInline(Loc, PrevSpec);
550      break;
551
552    // Gross GCC-ism that we are forced support. FIXME: make an extension?
553    case tok::less:
554      if (!DS.hasTypeSpecifier()) {
555        SourceLocation endProtoLoc;
556        llvm::SmallVector<IdentifierInfo *, 8> ProtocolRefs;
557        ParseObjCProtocolReferences(ProtocolRefs, endProtoLoc);
558        llvm::SmallVector<DeclTy *, 8> *ProtocolDecl =
559                new llvm::SmallVector<DeclTy *, 8>;
560        DS.setProtocolQualifiers(ProtocolDecl);
561        Actions.FindProtocolDeclaration(Loc,
562                  &ProtocolRefs[0], ProtocolRefs.size(),
563                  *ProtocolDecl);
564      }
565      continue;
566    }
567    // If the specifier combination wasn't legal, issue a diagnostic.
568    if (isInvalid) {
569      assert(PrevSpec && "Method did not return previous specifier!");
570      if (isInvalid == 1)  // Error.
571        Diag(Tok, diag::err_invalid_decl_spec_combination, PrevSpec);
572      else                 // extwarn.
573        Diag(Tok, diag::ext_duplicate_declspec, PrevSpec);
574    }
575    DS.SetRangeEnd(Tok.getLocation());
576    ConsumeToken();
577  }
578}
579
580/// ParseTag - Parse "struct-or-union-or-class-or-enum identifier[opt]", where
581/// the first token has already been read and has been turned into an instance
582/// of DeclSpec::TST (TagType).  This returns true if there is an error parsing,
583/// otherwise it returns false and fills in Decl.
584bool Parser::ParseTag(DeclTy *&Decl, unsigned TagType, SourceLocation StartLoc){
585  AttributeList *Attr = 0;
586  // If attributes exist after tag, parse them.
587  if (Tok.is(tok::kw___attribute))
588    Attr = ParseAttributes();
589
590  // Must have either 'struct name' or 'struct {...}'.
591  if (Tok.isNot(tok::identifier) && Tok.isNot(tok::l_brace)) {
592    Diag(Tok, diag::err_expected_ident_lbrace);
593
594    // Skip the rest of this declarator, up until the comma or semicolon.
595    SkipUntil(tok::comma, true);
596    return true;
597  }
598
599  // If an identifier is present, consume and remember it.
600  IdentifierInfo *Name = 0;
601  SourceLocation NameLoc;
602  if (Tok.is(tok::identifier)) {
603    Name = Tok.getIdentifierInfo();
604    NameLoc = ConsumeToken();
605  }
606
607  // There are three options here.  If we have 'struct foo;', then this is a
608  // forward declaration.  If we have 'struct foo {...' then this is a
609  // definition. Otherwise we have something like 'struct foo xyz', a reference.
610  //
611  // This is needed to handle stuff like this right (C99 6.7.2.3p11):
612  // struct foo {..};  void bar() { struct foo; }    <- new foo in bar.
613  // struct foo {..};  void bar() { struct foo x; }  <- use of old foo.
614  //
615  Action::TagKind TK;
616  if (Tok.is(tok::l_brace))
617    TK = Action::TK_Definition;
618  else if (Tok.is(tok::semi))
619    TK = Action::TK_Declaration;
620  else
621    TK = Action::TK_Reference;
622  Decl = Actions.ActOnTag(CurScope, TagType, TK, StartLoc, Name, NameLoc, Attr);
623  return false;
624}
625
626/// ParseStructDeclaration - Parse a struct declaration without the terminating
627/// semicolon.
628///
629///       struct-declaration:
630///         specifier-qualifier-list struct-declarator-list
631/// [GNU]   __extension__ struct-declaration
632/// [GNU]   specifier-qualifier-list
633///       struct-declarator-list:
634///         struct-declarator
635///         struct-declarator-list ',' struct-declarator
636/// [GNU]   struct-declarator-list ',' attributes[opt] struct-declarator
637///       struct-declarator:
638///         declarator
639/// [GNU]   declarator attributes[opt]
640///         declarator[opt] ':' constant-expression
641/// [GNU]   declarator[opt] ':' constant-expression attributes[opt]
642///
643void Parser::
644ParseStructDeclaration(DeclSpec &DS,
645                       llvm::SmallVectorImpl<FieldDeclarator> &Fields) {
646  // FIXME: When __extension__ is specified, disable extension diagnostics.
647  while (Tok.is(tok::kw___extension__))
648    ConsumeToken();
649
650  // Parse the common specifier-qualifiers-list piece.
651  SourceLocation DSStart = Tok.getLocation();
652  ParseSpecifierQualifierList(DS);
653  // TODO: Does specifier-qualifier list correctly check that *something* is
654  // specified?
655
656  // If there are no declarators, issue a warning.
657  if (Tok.is(tok::semi)) {
658    Diag(DSStart, diag::w_no_declarators);
659    return;
660  }
661
662  // Read struct-declarators until we find the semicolon.
663  Fields.push_back(FieldDeclarator(DS));
664  while (1) {
665    FieldDeclarator &DeclaratorInfo = Fields.back();
666
667    /// struct-declarator: declarator
668    /// struct-declarator: declarator[opt] ':' constant-expression
669    if (Tok.isNot(tok::colon))
670      ParseDeclarator(DeclaratorInfo.D);
671
672    if (Tok.is(tok::colon)) {
673      ConsumeToken();
674      ExprResult Res = ParseConstantExpression();
675      if (Res.isInvalid)
676        SkipUntil(tok::semi, true, true);
677      else
678        DeclaratorInfo.BitfieldSize = Res.Val;
679    }
680
681    // If attributes exist after the declarator, parse them.
682    if (Tok.is(tok::kw___attribute))
683      DeclaratorInfo.D.AddAttributes(ParseAttributes());
684
685    // If we don't have a comma, it is either the end of the list (a ';')
686    // or an error, bail out.
687    if (Tok.isNot(tok::comma))
688      return;
689
690    // Consume the comma.
691    ConsumeToken();
692
693    // Parse the next declarator.
694    Fields.push_back(FieldDeclarator(DS));
695
696    // Attributes are only allowed on the second declarator.
697    if (Tok.is(tok::kw___attribute))
698      Fields.back().D.AddAttributes(ParseAttributes());
699  }
700}
701
702/// ParseStructUnionBody
703///       struct-contents:
704///         struct-declaration-list
705/// [EXT]   empty
706/// [GNU]   "struct-declaration-list" without terminatoring ';'
707///       struct-declaration-list:
708///         struct-declaration
709///         struct-declaration-list struct-declaration
710/// [OBC]   '@' 'defs' '(' class-name ')'
711///
712void Parser::ParseStructUnionBody(SourceLocation RecordLoc,
713                                  unsigned TagType, DeclTy *TagDecl) {
714  SourceLocation LBraceLoc = ConsumeBrace();
715
716  // Empty structs are an extension in C (C99 6.7.2.1p7), but are allowed in
717  // C++.
718  if (Tok.is(tok::r_brace) && !getLang().CPlusPlus)
719    Diag(Tok, diag::ext_empty_struct_union_enum,
720         DeclSpec::getSpecifierName((DeclSpec::TST)TagType));
721
722  llvm::SmallVector<DeclTy*, 32> FieldDecls;
723  llvm::SmallVector<FieldDeclarator, 8> FieldDeclarators;
724
725  // While we still have something to read, read the declarations in the struct.
726  while (Tok.isNot(tok::r_brace) && Tok.isNot(tok::eof)) {
727    // Each iteration of this loop reads one struct-declaration.
728
729    // Check for extraneous top-level semicolon.
730    if (Tok.is(tok::semi)) {
731      Diag(Tok, diag::ext_extra_struct_semi);
732      ConsumeToken();
733      continue;
734    }
735
736    // Parse all the comma separated declarators.
737    DeclSpec DS;
738    FieldDeclarators.clear();
739    if (!Tok.is(tok::at)) {
740      ParseStructDeclaration(DS, FieldDeclarators);
741
742      // Convert them all to fields.
743      for (unsigned i = 0, e = FieldDeclarators.size(); i != e; ++i) {
744        FieldDeclarator &FD = FieldDeclarators[i];
745        // Install the declarator into the current TagDecl.
746        DeclTy *Field = Actions.ActOnField(CurScope,
747                                           DS.getSourceRange().getBegin(),
748                                           FD.D, FD.BitfieldSize);
749        FieldDecls.push_back(Field);
750      }
751    } else { // Handle @defs
752      ConsumeToken();
753      if (!Tok.isObjCAtKeyword(tok::objc_defs)) {
754        Diag(Tok, diag::err_unexpected_at);
755        SkipUntil(tok::semi, true, true);
756        continue;
757      }
758      ConsumeToken();
759      ExpectAndConsume(tok::l_paren, diag::err_expected_lparen);
760      if (!Tok.is(tok::identifier)) {
761        Diag(Tok, diag::err_expected_ident);
762        SkipUntil(tok::semi, true, true);
763        continue;
764      }
765      llvm::SmallVector<DeclTy*, 16> Fields;
766      Actions.ActOnDefs(CurScope, Tok.getLocation(), Tok.getIdentifierInfo(),
767          Fields);
768      FieldDecls.insert(FieldDecls.end(), Fields.begin(), Fields.end());
769      ConsumeToken();
770      ExpectAndConsume(tok::r_paren, diag::err_expected_rparen);
771    }
772
773    if (Tok.is(tok::semi)) {
774      ConsumeToken();
775    } else if (Tok.is(tok::r_brace)) {
776      Diag(Tok.getLocation(), diag::ext_expected_semi_decl_list);
777      break;
778    } else {
779      Diag(Tok, diag::err_expected_semi_decl_list);
780      // Skip to end of block or statement
781      SkipUntil(tok::r_brace, true, true);
782    }
783  }
784
785  SourceLocation RBraceLoc = MatchRHSPunctuation(tok::r_brace, LBraceLoc);
786
787  Actions.ActOnFields(CurScope,
788                      RecordLoc,TagDecl,&FieldDecls[0],FieldDecls.size(),
789                      LBraceLoc, RBraceLoc);
790
791  AttributeList *AttrList = 0;
792  // If attributes exist after struct contents, parse them.
793  if (Tok.is(tok::kw___attribute))
794    AttrList = ParseAttributes(); // FIXME: where should I put them?
795}
796
797
798/// ParseEnumSpecifier
799///       enum-specifier: [C99 6.7.2.2]
800///         'enum' identifier[opt] '{' enumerator-list '}'
801/// [C99]   'enum' identifier[opt] '{' enumerator-list ',' '}'
802/// [GNU]   'enum' attributes[opt] identifier[opt] '{' enumerator-list ',' [opt]
803///                                                 '}' attributes[opt]
804///         'enum' identifier
805/// [GNU]   'enum' attributes[opt] identifier
806void Parser::ParseEnumSpecifier(DeclSpec &DS) {
807  assert(Tok.is(tok::kw_enum) && "Not an enum specifier");
808  SourceLocation StartLoc = ConsumeToken();
809
810  // Parse the tag portion of this.
811  DeclTy *TagDecl;
812  if (ParseTag(TagDecl, DeclSpec::TST_enum, StartLoc))
813    return;
814
815  if (Tok.is(tok::l_brace))
816    ParseEnumBody(StartLoc, TagDecl);
817
818  // TODO: semantic analysis on the declspec for enums.
819  const char *PrevSpec = 0;
820  if (DS.SetTypeSpecType(DeclSpec::TST_enum, StartLoc, PrevSpec, TagDecl))
821    Diag(StartLoc, diag::err_invalid_decl_spec_combination, PrevSpec);
822}
823
824/// ParseEnumBody - Parse a {} enclosed enumerator-list.
825///       enumerator-list:
826///         enumerator
827///         enumerator-list ',' enumerator
828///       enumerator:
829///         enumeration-constant
830///         enumeration-constant '=' constant-expression
831///       enumeration-constant:
832///         identifier
833///
834void Parser::ParseEnumBody(SourceLocation StartLoc, DeclTy *EnumDecl) {
835  SourceLocation LBraceLoc = ConsumeBrace();
836
837  // C does not allow an empty enumerator-list, C++ does [dcl.enum].
838  if (Tok.is(tok::r_brace) && !getLang().CPlusPlus)
839    Diag(Tok, diag::ext_empty_struct_union_enum, "enum");
840
841  llvm::SmallVector<DeclTy*, 32> EnumConstantDecls;
842
843  DeclTy *LastEnumConstDecl = 0;
844
845  // Parse the enumerator-list.
846  while (Tok.is(tok::identifier)) {
847    IdentifierInfo *Ident = Tok.getIdentifierInfo();
848    SourceLocation IdentLoc = ConsumeToken();
849
850    SourceLocation EqualLoc;
851    ExprTy *AssignedVal = 0;
852    if (Tok.is(tok::equal)) {
853      EqualLoc = ConsumeToken();
854      ExprResult Res = ParseConstantExpression();
855      if (Res.isInvalid)
856        SkipUntil(tok::comma, tok::r_brace, true, true);
857      else
858        AssignedVal = Res.Val;
859    }
860
861    // Install the enumerator constant into EnumDecl.
862    DeclTy *EnumConstDecl = Actions.ActOnEnumConstant(CurScope, EnumDecl,
863                                                      LastEnumConstDecl,
864                                                      IdentLoc, Ident,
865                                                      EqualLoc, AssignedVal);
866    EnumConstantDecls.push_back(EnumConstDecl);
867    LastEnumConstDecl = EnumConstDecl;
868
869    if (Tok.isNot(tok::comma))
870      break;
871    SourceLocation CommaLoc = ConsumeToken();
872
873    if (Tok.isNot(tok::identifier) && !getLang().C99)
874      Diag(CommaLoc, diag::ext_c99_enumerator_list_comma);
875  }
876
877  // Eat the }.
878  MatchRHSPunctuation(tok::r_brace, LBraceLoc);
879
880  Actions.ActOnEnumBody(StartLoc, EnumDecl, &EnumConstantDecls[0],
881                        EnumConstantDecls.size());
882
883  DeclTy *AttrList = 0;
884  // If attributes exist after the identifier list, parse them.
885  if (Tok.is(tok::kw___attribute))
886    AttrList = ParseAttributes(); // FIXME: where do they do?
887}
888
889/// isTypeSpecifierQualifier - Return true if the current token could be the
890/// start of a type-qualifier-list.
891bool Parser::isTypeQualifier() const {
892  switch (Tok.getKind()) {
893  default: return false;
894    // type-qualifier
895  case tok::kw_const:
896  case tok::kw_volatile:
897  case tok::kw_restrict:
898    return true;
899  }
900}
901
902/// isTypeSpecifierQualifier - Return true if the current token could be the
903/// start of a specifier-qualifier-list.
904bool Parser::isTypeSpecifierQualifier() const {
905  switch (Tok.getKind()) {
906  default: return false;
907    // GNU attributes support.
908  case tok::kw___attribute:
909    // GNU typeof support.
910  case tok::kw_typeof:
911    // GNU bizarre protocol extension. FIXME: make an extension?
912  case tok::less:
913
914    // type-specifiers
915  case tok::kw_short:
916  case tok::kw_long:
917  case tok::kw_signed:
918  case tok::kw_unsigned:
919  case tok::kw__Complex:
920  case tok::kw__Imaginary:
921  case tok::kw_void:
922  case tok::kw_char:
923  case tok::kw_int:
924  case tok::kw_float:
925  case tok::kw_double:
926  case tok::kw_bool:
927  case tok::kw__Bool:
928  case tok::kw__Decimal32:
929  case tok::kw__Decimal64:
930  case tok::kw__Decimal128:
931
932    // struct-or-union-specifier (C99) or class-specifier (C++)
933  case tok::kw_class:
934  case tok::kw_struct:
935  case tok::kw_union:
936    // enum-specifier
937  case tok::kw_enum:
938
939    // type-qualifier
940  case tok::kw_const:
941  case tok::kw_volatile:
942  case tok::kw_restrict:
943    return true;
944
945    // typedef-name
946  case tok::identifier:
947    return Actions.isTypeName(*Tok.getIdentifierInfo(), CurScope) != 0;
948  }
949}
950
951/// isDeclarationSpecifier() - Return true if the current token is part of a
952/// declaration specifier.
953bool Parser::isDeclarationSpecifier() const {
954  switch (Tok.getKind()) {
955  default: return false;
956    // storage-class-specifier
957  case tok::kw_typedef:
958  case tok::kw_extern:
959  case tok::kw___private_extern__:
960  case tok::kw_static:
961  case tok::kw_auto:
962  case tok::kw_register:
963  case tok::kw___thread:
964
965    // type-specifiers
966  case tok::kw_short:
967  case tok::kw_long:
968  case tok::kw_signed:
969  case tok::kw_unsigned:
970  case tok::kw__Complex:
971  case tok::kw__Imaginary:
972  case tok::kw_void:
973  case tok::kw_char:
974  case tok::kw_int:
975  case tok::kw_float:
976  case tok::kw_double:
977  case tok::kw_bool:
978  case tok::kw__Bool:
979  case tok::kw__Decimal32:
980  case tok::kw__Decimal64:
981  case tok::kw__Decimal128:
982
983    // struct-or-union-specifier (C99) or class-specifier (C++)
984  case tok::kw_class:
985  case tok::kw_struct:
986  case tok::kw_union:
987    // enum-specifier
988  case tok::kw_enum:
989
990    // type-qualifier
991  case tok::kw_const:
992  case tok::kw_volatile:
993  case tok::kw_restrict:
994
995    // function-specifier
996  case tok::kw_inline:
997
998    // GNU typeof support.
999  case tok::kw_typeof:
1000
1001    // GNU attributes.
1002  case tok::kw___attribute:
1003
1004    // GNU bizarre protocol extension. FIXME: make an extension?
1005  case tok::less:
1006    return true;
1007
1008    // typedef-name
1009  case tok::identifier:
1010    return Actions.isTypeName(*Tok.getIdentifierInfo(), CurScope) != 0;
1011  }
1012}
1013
1014
1015/// ParseTypeQualifierListOpt
1016///       type-qualifier-list: [C99 6.7.5]
1017///         type-qualifier
1018/// [GNU]   attributes
1019///         type-qualifier-list type-qualifier
1020/// [GNU]   type-qualifier-list attributes
1021///
1022void Parser::ParseTypeQualifierListOpt(DeclSpec &DS) {
1023  while (1) {
1024    int isInvalid = false;
1025    const char *PrevSpec = 0;
1026    SourceLocation Loc = Tok.getLocation();
1027
1028    switch (Tok.getKind()) {
1029    default:
1030      // If this is not a type-qualifier token, we're done reading type
1031      // qualifiers.  First verify that DeclSpec's are consistent.
1032      DS.Finish(Diags, PP.getSourceManager(), getLang());
1033      return;
1034    case tok::kw_const:
1035      isInvalid = DS.SetTypeQual(DeclSpec::TQ_const   , Loc, PrevSpec,
1036                                 getLang())*2;
1037      break;
1038    case tok::kw_volatile:
1039      isInvalid = DS.SetTypeQual(DeclSpec::TQ_volatile, Loc, PrevSpec,
1040                                 getLang())*2;
1041      break;
1042    case tok::kw_restrict:
1043      isInvalid = DS.SetTypeQual(DeclSpec::TQ_restrict, Loc, PrevSpec,
1044                                 getLang())*2;
1045      break;
1046    case tok::kw___attribute:
1047      DS.AddAttributes(ParseAttributes());
1048      continue; // do *not* consume the next token!
1049    }
1050
1051    // If the specifier combination wasn't legal, issue a diagnostic.
1052    if (isInvalid) {
1053      assert(PrevSpec && "Method did not return previous specifier!");
1054      if (isInvalid == 1)  // Error.
1055        Diag(Tok, diag::err_invalid_decl_spec_combination, PrevSpec);
1056      else                 // extwarn.
1057        Diag(Tok, diag::ext_duplicate_declspec, PrevSpec);
1058    }
1059    ConsumeToken();
1060  }
1061}
1062
1063
1064/// ParseDeclarator - Parse and verify a newly-initialized declarator.
1065///
1066void Parser::ParseDeclarator(Declarator &D) {
1067  /// This implements the 'declarator' production in the C grammar, then checks
1068  /// for well-formedness and issues diagnostics.
1069  ParseDeclaratorInternal(D);
1070}
1071
1072/// ParseDeclaratorInternal
1073///       declarator: [C99 6.7.5]
1074///         pointer[opt] direct-declarator
1075/// [C++]   '&' declarator [C++ 8p4, dcl.decl]
1076/// [GNU]   '&' restrict[opt] attributes[opt] declarator
1077///
1078///       pointer: [C99 6.7.5]
1079///         '*' type-qualifier-list[opt]
1080///         '*' type-qualifier-list[opt] pointer
1081///
1082void Parser::ParseDeclaratorInternal(Declarator &D) {
1083  tok::TokenKind Kind = Tok.getKind();
1084
1085  // Not a pointer or C++ reference.
1086  if (Kind != tok::star && (Kind != tok::amp || !getLang().CPlusPlus))
1087    return ParseDirectDeclarator(D);
1088
1089  // Otherwise, '*' -> pointer or '&' -> reference.
1090  SourceLocation Loc = ConsumeToken();  // Eat the * or &.
1091
1092  if (Kind == tok::star) {
1093    // Is a pointer.
1094    DeclSpec DS;
1095
1096    ParseTypeQualifierListOpt(DS);
1097
1098    // Recursively parse the declarator.
1099    ParseDeclaratorInternal(D);
1100
1101    // Remember that we parsed a pointer type, and remember the type-quals.
1102    D.AddTypeInfo(DeclaratorChunk::getPointer(DS.getTypeQualifiers(), Loc,
1103                                              DS.TakeAttributes()));
1104  } else {
1105    // Is a reference
1106    DeclSpec DS;
1107
1108    // C++ 8.3.2p1: cv-qualified references are ill-formed except when the
1109    // cv-qualifiers are introduced through the use of a typedef or of a
1110    // template type argument, in which case the cv-qualifiers are ignored.
1111    //
1112    // [GNU] Retricted references are allowed.
1113    // [GNU] Attributes on references are allowed.
1114    ParseTypeQualifierListOpt(DS);
1115
1116    if (DS.getTypeQualifiers() != DeclSpec::TQ_unspecified) {
1117      if (DS.getTypeQualifiers() & DeclSpec::TQ_const)
1118        Diag(DS.getConstSpecLoc(),
1119             diag::err_invalid_reference_qualifier_application,
1120             "const");
1121      if (DS.getTypeQualifiers() & DeclSpec::TQ_volatile)
1122        Diag(DS.getVolatileSpecLoc(),
1123             diag::err_invalid_reference_qualifier_application,
1124             "volatile");
1125    }
1126
1127    // Recursively parse the declarator.
1128    ParseDeclaratorInternal(D);
1129
1130    // Remember that we parsed a reference type. It doesn't have type-quals.
1131    D.AddTypeInfo(DeclaratorChunk::getReference(DS.getTypeQualifiers(), Loc,
1132                                                DS.TakeAttributes()));
1133  }
1134}
1135
1136/// ParseDirectDeclarator
1137///       direct-declarator: [C99 6.7.5]
1138///         identifier
1139///         '(' declarator ')'
1140/// [GNU]   '(' attributes declarator ')'
1141/// [C90]   direct-declarator '[' constant-expression[opt] ']'
1142/// [C99]   direct-declarator '[' type-qual-list[opt] assignment-expr[opt] ']'
1143/// [C99]   direct-declarator '[' 'static' type-qual-list[opt] assign-expr ']'
1144/// [C99]   direct-declarator '[' type-qual-list 'static' assignment-expr ']'
1145/// [C99]   direct-declarator '[' type-qual-list[opt] '*' ']'
1146///         direct-declarator '(' parameter-type-list ')'
1147///         direct-declarator '(' identifier-list[opt] ')'
1148/// [GNU]   direct-declarator '(' parameter-forward-declarations
1149///                    parameter-type-list[opt] ')'
1150///
1151void Parser::ParseDirectDeclarator(Declarator &D) {
1152  // Parse the first direct-declarator seen.
1153  if (Tok.is(tok::identifier) && D.mayHaveIdentifier()) {
1154    assert(Tok.getIdentifierInfo() && "Not an identifier?");
1155    D.SetIdentifier(Tok.getIdentifierInfo(), Tok.getLocation());
1156    ConsumeToken();
1157  } else if (Tok.is(tok::l_paren)) {
1158    // direct-declarator: '(' declarator ')'
1159    // direct-declarator: '(' attributes declarator ')'
1160    // Example: 'char (*X)'   or 'int (*XX)(void)'
1161    ParseParenDeclarator(D);
1162  } else if (D.mayOmitIdentifier()) {
1163    // This could be something simple like "int" (in which case the declarator
1164    // portion is empty), if an abstract-declarator is allowed.
1165    D.SetIdentifier(0, Tok.getLocation());
1166  } else {
1167    // Expected identifier or '('.
1168    Diag(Tok, diag::err_expected_ident_lparen);
1169    D.SetIdentifier(0, Tok.getLocation());
1170  }
1171
1172  assert(D.isPastIdentifier() &&
1173         "Haven't past the location of the identifier yet?");
1174
1175  while (1) {
1176    if (Tok.is(tok::l_paren)) {
1177      ParseFunctionDeclarator(ConsumeParen(), D);
1178    } else if (Tok.is(tok::l_square)) {
1179      ParseBracketDeclarator(D);
1180    } else {
1181      break;
1182    }
1183  }
1184}
1185
1186/// ParseParenDeclarator - We parsed the declarator D up to a paren.  This is
1187/// only called before the identifier, so these are most likely just grouping
1188/// parens for precedence.  If we find that these are actually function
1189/// parameter parens in an abstract-declarator, we call ParseFunctionDeclarator.
1190///
1191///       direct-declarator:
1192///         '(' declarator ')'
1193/// [GNU]   '(' attributes declarator ')'
1194///
1195void Parser::ParseParenDeclarator(Declarator &D) {
1196  SourceLocation StartLoc = ConsumeParen();
1197  assert(!D.isPastIdentifier() && "Should be called before passing identifier");
1198
1199  // If we haven't past the identifier yet (or where the identifier would be
1200  // stored, if this is an abstract declarator), then this is probably just
1201  // grouping parens. However, if this could be an abstract-declarator, then
1202  // this could also be the start of function arguments (consider 'void()').
1203  bool isGrouping;
1204
1205  if (!D.mayOmitIdentifier()) {
1206    // If this can't be an abstract-declarator, this *must* be a grouping
1207    // paren, because we haven't seen the identifier yet.
1208    isGrouping = true;
1209  } else if (Tok.is(tok::r_paren) ||           // 'int()' is a function.
1210             isDeclarationSpecifier()) {       // 'int(int)' is a function.
1211    // This handles C99 6.7.5.3p11: in "typedef int X; void foo(X)", X is
1212    // considered to be a type, not a K&R identifier-list.
1213    isGrouping = false;
1214  } else {
1215    // Otherwise, this is a grouping paren, e.g. 'int (*X)' or 'int(X)'.
1216    isGrouping = true;
1217  }
1218
1219  // If this is a grouping paren, handle:
1220  // direct-declarator: '(' declarator ')'
1221  // direct-declarator: '(' attributes declarator ')'
1222  if (isGrouping) {
1223    if (Tok.is(tok::kw___attribute))
1224      D.AddAttributes(ParseAttributes());
1225
1226    ParseDeclaratorInternal(D);
1227    // Match the ')'.
1228    MatchRHSPunctuation(tok::r_paren, StartLoc);
1229    return;
1230  }
1231
1232  // Okay, if this wasn't a grouping paren, it must be the start of a function
1233  // argument list.  Recognize that this declarator will never have an
1234  // identifier (and remember where it would have been), then fall through to
1235  // the handling of argument lists.
1236  D.SetIdentifier(0, Tok.getLocation());
1237
1238  ParseFunctionDeclarator(StartLoc, D);
1239}
1240
1241/// ParseFunctionDeclarator - We are after the identifier and have parsed the
1242/// declarator D up to a paren, which indicates that we are parsing function
1243/// arguments.
1244///
1245/// This method also handles this portion of the grammar:
1246///       parameter-type-list: [C99 6.7.5]
1247///         parameter-list
1248///         parameter-list ',' '...'
1249///
1250///       parameter-list: [C99 6.7.5]
1251///         parameter-declaration
1252///         parameter-list ',' parameter-declaration
1253///
1254///       parameter-declaration: [C99 6.7.5]
1255///         declaration-specifiers declarator
1256/// [C++]   declaration-specifiers declarator '=' assignment-expression
1257/// [GNU]   declaration-specifiers declarator attributes
1258///         declaration-specifiers abstract-declarator[opt]
1259/// [C++]   declaration-specifiers abstract-declarator[opt]
1260///           '=' assignment-expression
1261/// [GNU]   declaration-specifiers abstract-declarator[opt] attributes
1262///
1263void Parser::ParseFunctionDeclarator(SourceLocation LParenLoc, Declarator &D) {
1264  // lparen is already consumed!
1265  assert(D.isPastIdentifier() && "Should not call before identifier!");
1266
1267  // Okay, this is the parameter list of a function definition, or it is an
1268  // identifier list of a K&R-style function.
1269
1270  if (Tok.is(tok::r_paren)) {
1271    // Remember that we parsed a function type, and remember the attributes.
1272    // int() -> no prototype, no '...'.
1273    D.AddTypeInfo(DeclaratorChunk::getFunction(/*prototype*/ false,
1274                                               /*variadic*/ false,
1275                                               /*arglist*/ 0, 0, LParenLoc));
1276
1277    ConsumeParen();  // Eat the closing ')'.
1278    return;
1279  } else if (Tok.is(tok::identifier) &&
1280             // K&R identifier lists can't have typedefs as identifiers, per
1281             // C99 6.7.5.3p11.
1282             !Actions.isTypeName(*Tok.getIdentifierInfo(), CurScope)) {
1283    // Identifier list.  Note that '(' identifier-list ')' is only allowed for
1284    // normal declarators, not for abstract-declarators.
1285    return ParseFunctionDeclaratorIdentifierList(LParenLoc, D);
1286  }
1287
1288  // Finally, a normal, non-empty parameter type list.
1289
1290  // Build up an array of information about the parsed arguments.
1291  llvm::SmallVector<DeclaratorChunk::ParamInfo, 16> ParamInfo;
1292
1293  // Enter function-declaration scope, limiting any declarators to the
1294  // function prototype scope, including parameter declarators.
1295  EnterScope(Scope::FnScope|Scope::DeclScope);
1296
1297  bool IsVariadic = false;
1298  while (1) {
1299    if (Tok.is(tok::ellipsis)) {
1300      IsVariadic = true;
1301
1302      // Check to see if this is "void(...)" which is not allowed.
1303      if (ParamInfo.empty()) {
1304        // Otherwise, parse parameter type list.  If it starts with an
1305        // ellipsis,  diagnose the malformed function.
1306        Diag(Tok, diag::err_ellipsis_first_arg);
1307        IsVariadic = false;       // Treat this like 'void()'.
1308      }
1309
1310      ConsumeToken();     // Consume the ellipsis.
1311      break;
1312    }
1313
1314    SourceLocation DSStart = Tok.getLocation();
1315
1316    // Parse the declaration-specifiers.
1317    DeclSpec DS;
1318    ParseDeclarationSpecifiers(DS);
1319
1320    // Parse the declarator.  This is "PrototypeContext", because we must
1321    // accept either 'declarator' or 'abstract-declarator' here.
1322    Declarator ParmDecl(DS, Declarator::PrototypeContext);
1323    ParseDeclarator(ParmDecl);
1324
1325    // Parse GNU attributes, if present.
1326    if (Tok.is(tok::kw___attribute))
1327      ParmDecl.AddAttributes(ParseAttributes());
1328
1329    // Remember this parsed parameter in ParamInfo.
1330    IdentifierInfo *ParmII = ParmDecl.getIdentifier();
1331
1332    // If no parameter was specified, verify that *something* was specified,
1333    // otherwise we have a missing type and identifier.
1334    if (DS.getParsedSpecifiers() == DeclSpec::PQ_None &&
1335        ParmDecl.getIdentifier() == 0 && ParmDecl.getNumTypeObjects() == 0) {
1336      // Completely missing, emit error.
1337      Diag(DSStart, diag::err_missing_param);
1338    } else {
1339      // Otherwise, we have something.  Add it and let semantic analysis try
1340      // to grok it and add the result to the ParamInfo we are building.
1341
1342      // Inform the actions module about the parameter declarator, so it gets
1343      // added to the current scope.
1344      DeclTy *Param = Actions.ActOnParamDeclarator(CurScope, ParmDecl);
1345
1346      // Parse the default argument, if any. We parse the default
1347      // arguments in all dialects; the semantic analysis in
1348      // ActOnParamDefaultArgument will reject the default argument in
1349      // C.
1350      if (Tok.is(tok::equal)) {
1351        SourceLocation EqualLoc = Tok.getLocation();
1352
1353        // Consume the '='.
1354        ConsumeToken();
1355
1356        // Parse the default argument
1357        ExprResult DefArgResult = ParseAssignmentExpression();
1358        if (DefArgResult.isInvalid) {
1359          SkipUntil(tok::comma, tok::r_paren, true, true);
1360        } else {
1361          // Inform the actions module about the default argument
1362          Actions.ActOnParamDefaultArgument(Param, EqualLoc, DefArgResult.Val);
1363        }
1364      }
1365
1366      ParamInfo.push_back(DeclaratorChunk::ParamInfo(ParmII,
1367                             ParmDecl.getIdentifierLoc(), Param));
1368    }
1369
1370    // If the next token is a comma, consume it and keep reading arguments.
1371    if (Tok.isNot(tok::comma)) break;
1372
1373    // Consume the comma.
1374    ConsumeToken();
1375  }
1376
1377  // Leave prototype scope.
1378  ExitScope();
1379
1380  // Remember that we parsed a function type, and remember the attributes.
1381  D.AddTypeInfo(DeclaratorChunk::getFunction(/*proto*/true, IsVariadic,
1382                                             &ParamInfo[0], ParamInfo.size(),
1383                                             LParenLoc));
1384
1385  // If we have the closing ')', eat it and we're done.
1386  MatchRHSPunctuation(tok::r_paren, LParenLoc);
1387}
1388
1389/// ParseFunctionDeclaratorIdentifierList - While parsing a function declarator
1390/// we found a K&R-style identifier list instead of a type argument list.  The
1391/// current token is known to be the first identifier in the list.
1392///
1393///       identifier-list: [C99 6.7.5]
1394///         identifier
1395///         identifier-list ',' identifier
1396///
1397void Parser::ParseFunctionDeclaratorIdentifierList(SourceLocation LParenLoc,
1398                                                   Declarator &D) {
1399  // Build up an array of information about the parsed arguments.
1400  llvm::SmallVector<DeclaratorChunk::ParamInfo, 16> ParamInfo;
1401  llvm::SmallSet<const IdentifierInfo*, 16> ParamsSoFar;
1402
1403  // If there was no identifier specified for the declarator, either we are in
1404  // an abstract-declarator, or we are in a parameter declarator which was found
1405  // to be abstract.  In abstract-declarators, identifier lists are not valid:
1406  // diagnose this.
1407  if (!D.getIdentifier())
1408    Diag(Tok, diag::ext_ident_list_in_param);
1409
1410  // Tok is known to be the first identifier in the list.  Remember this
1411  // identifier in ParamInfo.
1412  ParamsSoFar.insert(Tok.getIdentifierInfo());
1413  ParamInfo.push_back(DeclaratorChunk::ParamInfo(Tok.getIdentifierInfo(),
1414                                                 Tok.getLocation(), 0));
1415
1416  ConsumeToken();  // eat the first identifier.
1417
1418  while (Tok.is(tok::comma)) {
1419    // Eat the comma.
1420    ConsumeToken();
1421
1422    // If this isn't an identifier, report the error and skip until ')'.
1423    if (Tok.isNot(tok::identifier)) {
1424      Diag(Tok, diag::err_expected_ident);
1425      SkipUntil(tok::r_paren);
1426      return;
1427    }
1428
1429    IdentifierInfo *ParmII = Tok.getIdentifierInfo();
1430
1431    // Reject 'typedef int y; int test(x, y)', but continue parsing.
1432    if (Actions.isTypeName(*ParmII, CurScope))
1433      Diag(Tok, diag::err_unexpected_typedef_ident, ParmII->getName());
1434
1435    // Verify that the argument identifier has not already been mentioned.
1436    if (!ParamsSoFar.insert(ParmII)) {
1437      Diag(Tok.getLocation(), diag::err_param_redefinition, ParmII->getName());
1438    } else {
1439      // Remember this identifier in ParamInfo.
1440      ParamInfo.push_back(DeclaratorChunk::ParamInfo(ParmII,
1441                                                     Tok.getLocation(), 0));
1442    }
1443
1444    // Eat the identifier.
1445    ConsumeToken();
1446  }
1447
1448  // Remember that we parsed a function type, and remember the attributes.  This
1449  // function type is always a K&R style function type, which is not varargs and
1450  // has no prototype.
1451  D.AddTypeInfo(DeclaratorChunk::getFunction(/*proto*/false, /*varargs*/false,
1452                                             &ParamInfo[0], ParamInfo.size(),
1453                                             LParenLoc));
1454
1455  // If we have the closing ')', eat it and we're done.
1456  MatchRHSPunctuation(tok::r_paren, LParenLoc);
1457}
1458
1459/// [C90]   direct-declarator '[' constant-expression[opt] ']'
1460/// [C99]   direct-declarator '[' type-qual-list[opt] assignment-expr[opt] ']'
1461/// [C99]   direct-declarator '[' 'static' type-qual-list[opt] assign-expr ']'
1462/// [C99]   direct-declarator '[' type-qual-list 'static' assignment-expr ']'
1463/// [C99]   direct-declarator '[' type-qual-list[opt] '*' ']'
1464void Parser::ParseBracketDeclarator(Declarator &D) {
1465  SourceLocation StartLoc = ConsumeBracket();
1466
1467  // If valid, this location is the position where we read the 'static' keyword.
1468  SourceLocation StaticLoc;
1469  if (Tok.is(tok::kw_static))
1470    StaticLoc = ConsumeToken();
1471
1472  // If there is a type-qualifier-list, read it now.
1473  DeclSpec DS;
1474  ParseTypeQualifierListOpt(DS);
1475
1476  // If we haven't already read 'static', check to see if there is one after the
1477  // type-qualifier-list.
1478  if (!StaticLoc.isValid() && Tok.is(tok::kw_static))
1479    StaticLoc = ConsumeToken();
1480
1481  // Handle "direct-declarator [ type-qual-list[opt] * ]".
1482  bool isStar = false;
1483  ExprResult NumElements(false);
1484
1485  // Handle the case where we have '[*]' as the array size.  However, a leading
1486  // star could be the start of an expression, for example 'X[*p + 4]'.  Verify
1487  // the the token after the star is a ']'.  Since stars in arrays are
1488  // infrequent, use of lookahead is not costly here.
1489  if (Tok.is(tok::star) && GetLookAheadToken(1).is(tok::r_square)) {
1490    ConsumeToken();  // Eat the '*'.
1491
1492    if (StaticLoc.isValid())
1493      Diag(StaticLoc, diag::err_unspecified_vla_size_with_static);
1494    StaticLoc = SourceLocation();  // Drop the static.
1495    isStar = true;
1496  } else if (Tok.isNot(tok::r_square)) {
1497    // Parse the assignment-expression now.
1498    NumElements = ParseAssignmentExpression();
1499  }
1500
1501  // If there was an error parsing the assignment-expression, recover.
1502  if (NumElements.isInvalid) {
1503    // If the expression was invalid, skip it.
1504    SkipUntil(tok::r_square);
1505    return;
1506  }
1507
1508  MatchRHSPunctuation(tok::r_square, StartLoc);
1509
1510  // If C99 isn't enabled, emit an ext-warn if the arg list wasn't empty and if
1511  // it was not a constant expression.
1512  if (!getLang().C99) {
1513    // TODO: check C90 array constant exprness.
1514    if (isStar || StaticLoc.isValid() ||
1515        0/*TODO: NumElts is not a C90 constantexpr */)
1516      Diag(StartLoc, diag::ext_c99_array_usage);
1517  }
1518
1519  // Remember that we parsed a pointer type, and remember the type-quals.
1520  D.AddTypeInfo(DeclaratorChunk::getArray(DS.getTypeQualifiers(),
1521                                          StaticLoc.isValid(), isStar,
1522                                          NumElements.Val, StartLoc));
1523}
1524
1525/// [GNU] typeof-specifier:
1526///         typeof ( expressions )
1527///         typeof ( type-name )
1528///
1529void Parser::ParseTypeofSpecifier(DeclSpec &DS) {
1530  assert(Tok.is(tok::kw_typeof) && "Not a typeof specifier");
1531  const IdentifierInfo *BuiltinII = Tok.getIdentifierInfo();
1532  SourceLocation StartLoc = ConsumeToken();
1533
1534  if (Tok.isNot(tok::l_paren)) {
1535    Diag(Tok, diag::err_expected_lparen_after, BuiltinII->getName());
1536    return;
1537  }
1538  SourceLocation LParenLoc = ConsumeParen(), RParenLoc;
1539
1540  if (isTypeSpecifierQualifier()) {
1541    TypeTy *Ty = ParseTypeName();
1542
1543    assert(Ty && "Parser::ParseTypeofSpecifier(): missing type");
1544
1545    if (Tok.isNot(tok::r_paren)) {
1546      MatchRHSPunctuation(tok::r_paren, LParenLoc);
1547      return;
1548    }
1549    RParenLoc = ConsumeParen();
1550    const char *PrevSpec = 0;
1551    // Check for duplicate type specifiers (e.g. "int typeof(int)").
1552    if (DS.SetTypeSpecType(DeclSpec::TST_typeofType, StartLoc, PrevSpec, Ty))
1553      Diag(StartLoc, diag::err_invalid_decl_spec_combination, PrevSpec);
1554  } else { // we have an expression.
1555    ExprResult Result = ParseExpression();
1556
1557    if (Result.isInvalid || Tok.isNot(tok::r_paren)) {
1558      MatchRHSPunctuation(tok::r_paren, LParenLoc);
1559      return;
1560    }
1561    RParenLoc = ConsumeParen();
1562    const char *PrevSpec = 0;
1563    // Check for duplicate type specifiers (e.g. "int typeof(int)").
1564    if (DS.SetTypeSpecType(DeclSpec::TST_typeofExpr, StartLoc, PrevSpec,
1565                           Result.Val))
1566      Diag(StartLoc, diag::err_invalid_decl_spec_combination, PrevSpec);
1567  }
1568}
1569
1570
1571