ParseDecl.cpp revision f97409f352d12d4fcefb591b3757fcf3532865d5 
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)
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_struct:
520    case tok::kw_union:
521      ParseStructUnionSpecifier(DS);
522      continue;
523    case tok::kw_enum:
524      ParseEnumSpecifier(DS);
525      continue;
526
527    // GNU typeof support.
528    case tok::kw_typeof:
529      ParseTypeofSpecifier(DS);
530      continue;
531
532    // type-qualifier
533    case tok::kw_const:
534      isInvalid = DS.SetTypeQual(DeclSpec::TQ_const   , Loc, PrevSpec,
535                                 getLang())*2;
536      break;
537    case tok::kw_volatile:
538      isInvalid = DS.SetTypeQual(DeclSpec::TQ_volatile, Loc, PrevSpec,
539                                 getLang())*2;
540      break;
541    case tok::kw_restrict:
542      isInvalid = DS.SetTypeQual(DeclSpec::TQ_restrict, Loc, PrevSpec,
543                                 getLang())*2;
544      break;
545
546    // function-specifier
547    case tok::kw_inline:
548      isInvalid = DS.SetFunctionSpecInline(Loc, PrevSpec);
549      break;
550    }
551    // If the specifier combination wasn't legal, issue a diagnostic.
552    if (isInvalid) {
553      assert(PrevSpec && "Method did not return previous specifier!");
554      if (isInvalid == 1)  // Error.
555        Diag(Tok, diag::err_invalid_decl_spec_combination, PrevSpec);
556      else                 // extwarn.
557        Diag(Tok, diag::ext_duplicate_declspec, PrevSpec);
558    }
559    DS.SetRangeEnd(Tok.getLocation());
560    ConsumeToken();
561  }
562}
563
564/// ParseTag - Parse "struct-or-union-or-class-or-enum identifier[opt]", where
565/// the first token has already been read and has been turned into an instance
566/// of DeclSpec::TST (TagType).  This returns true if there is an error parsing,
567/// otherwise it returns false and fills in Decl.
568bool Parser::ParseTag(DeclTy *&Decl, unsigned TagType, SourceLocation StartLoc){
569  AttributeList *Attr = 0;
570  // If attributes exist after tag, parse them.
571  if (Tok.is(tok::kw___attribute))
572    Attr = ParseAttributes();
573
574  // Must have either 'struct name' or 'struct {...}'.
575  if (Tok.isNot(tok::identifier) && Tok.isNot(tok::l_brace)) {
576    Diag(Tok, diag::err_expected_ident_lbrace);
577
578    // Skip the rest of this declarator, up until the comma or semicolon.
579    SkipUntil(tok::comma, true);
580    return true;
581  }
582
583  // If an identifier is present, consume and remember it.
584  IdentifierInfo *Name = 0;
585  SourceLocation NameLoc;
586  if (Tok.is(tok::identifier)) {
587    Name = Tok.getIdentifierInfo();
588    NameLoc = ConsumeToken();
589  }
590
591  // There are three options here.  If we have 'struct foo;', then this is a
592  // forward declaration.  If we have 'struct foo {...' then this is a
593  // definition. Otherwise we have something like 'struct foo xyz', a reference.
594  //
595  // This is needed to handle stuff like this right (C99 6.7.2.3p11):
596  // struct foo {..};  void bar() { struct foo; }    <- new foo in bar.
597  // struct foo {..};  void bar() { struct foo x; }  <- use of old foo.
598  //
599  Action::TagKind TK;
600  if (Tok.is(tok::l_brace))
601    TK = Action::TK_Definition;
602  else if (Tok.is(tok::semi))
603    TK = Action::TK_Declaration;
604  else
605    TK = Action::TK_Reference;
606  Decl = Actions.ActOnTag(CurScope, TagType, TK, StartLoc, Name, NameLoc, Attr);
607  return false;
608}
609
610
611/// ParseStructUnionSpecifier
612///       struct-or-union-specifier: [C99 6.7.2.1]
613///         struct-or-union identifier[opt] '{' struct-contents '}'
614///         struct-or-union identifier
615/// [GNU]   struct-or-union attributes[opt] identifier[opt] '{' struct-contents
616///                                                         '}' attributes[opt]
617/// [GNU]   struct-or-union attributes[opt] identifier
618///       struct-or-union:
619///         'struct'
620///         'union'
621///
622void Parser::ParseStructUnionSpecifier(DeclSpec &DS) {
623  assert((Tok.is(tok::kw_struct) || Tok.is(tok::kw_union)) &&
624         "Not a struct/union specifier");
625  DeclSpec::TST TagType =
626    Tok.is(tok::kw_union) ? DeclSpec::TST_union : DeclSpec::TST_struct;
627  SourceLocation StartLoc = ConsumeToken();
628
629  // Parse the tag portion of this.
630  DeclTy *TagDecl;
631  if (ParseTag(TagDecl, TagType, StartLoc))
632    return;
633
634  // If there is a body, parse it and inform the actions module.
635  if (Tok.is(tok::l_brace))
636    ParseStructUnionBody(StartLoc, TagType, TagDecl);
637
638  const char *PrevSpec = 0;
639  if (DS.SetTypeSpecType(TagType, StartLoc, PrevSpec, TagDecl))
640    Diag(StartLoc, diag::err_invalid_decl_spec_combination, PrevSpec);
641}
642
643/// ParseStructDeclaration - Parse a struct declaration without the terminating
644/// semicolon.
645///
646///       struct-declaration:
647///         specifier-qualifier-list struct-declarator-list
648/// [GNU]   __extension__ struct-declaration
649/// [GNU]   specifier-qualifier-list
650///       struct-declarator-list:
651///         struct-declarator
652///         struct-declarator-list ',' struct-declarator
653/// [GNU]   struct-declarator-list ',' attributes[opt] struct-declarator
654///       struct-declarator:
655///         declarator
656/// [GNU]   declarator attributes[opt]
657///         declarator[opt] ':' constant-expression
658/// [GNU]   declarator[opt] ':' constant-expression attributes[opt]
659///
660void Parser::ParseStructDeclaration(DeclTy *TagDecl,
661  llvm::SmallVectorImpl<DeclTy*> &FieldDecls) {
662  // FIXME: When __extension__ is specified, disable extension diagnostics.
663  if (Tok.is(tok::kw___extension__))
664    ConsumeToken();
665
666  // Parse the common specifier-qualifiers-list piece.
667  DeclSpec DS;
668  SourceLocation SpecQualLoc = Tok.getLocation();
669  ParseSpecifierQualifierList(DS);
670  // TODO: Does specifier-qualifier list correctly check that *something* is
671  // specified?
672
673  // If there are no declarators, issue a warning.
674  if (Tok.is(tok::semi)) {
675    Diag(SpecQualLoc, diag::w_no_declarators);
676    return;
677  }
678
679  // Read struct-declarators until we find the semicolon.
680  Declarator DeclaratorInfo(DS, Declarator::MemberContext);
681
682  while (1) {
683    /// struct-declarator: declarator
684    /// struct-declarator: declarator[opt] ':' constant-expression
685    if (Tok.isNot(tok::colon))
686      ParseDeclarator(DeclaratorInfo);
687
688    ExprTy *BitfieldSize = 0;
689    if (Tok.is(tok::colon)) {
690      ConsumeToken();
691      ExprResult Res = ParseConstantExpression();
692      if (Res.isInvalid) {
693        SkipUntil(tok::semi, true, true);
694      } else {
695        BitfieldSize = Res.Val;
696      }
697    }
698
699    // If attributes exist after the declarator, parse them.
700    if (Tok.is(tok::kw___attribute))
701      DeclaratorInfo.AddAttributes(ParseAttributes());
702
703    // Install the declarator into the current TagDecl.
704    DeclTy *Field = Actions.ActOnField(CurScope, TagDecl, SpecQualLoc,
705                                       DeclaratorInfo, BitfieldSize);
706    FieldDecls.push_back(Field);
707
708    // If we don't have a comma, it is either the end of the list (a ';')
709    // or an error, bail out.
710    if (Tok.isNot(tok::comma))
711      return;
712
713    // Consume the comma.
714    ConsumeToken();
715
716    // Parse the next declarator.
717    DeclaratorInfo.clear();
718
719    // Attributes are only allowed on the second declarator.
720    if (Tok.is(tok::kw___attribute))
721      DeclaratorInfo.AddAttributes(ParseAttributes());
722  }
723}
724
725/// ParseStructUnionBody
726///       struct-contents:
727///         struct-declaration-list
728/// [EXT]   empty
729/// [GNU]   "struct-declaration-list" without terminatoring ';'
730///       struct-declaration-list:
731///         struct-declaration
732///         struct-declaration-list struct-declaration
733/// [OBC]   '@' 'defs' '(' class-name ')'                         [TODO]
734///
735void Parser::ParseStructUnionBody(SourceLocation RecordLoc,
736                                  unsigned TagType, DeclTy *TagDecl) {
737  SourceLocation LBraceLoc = ConsumeBrace();
738
739  // Empty structs are an extension in C (C99 6.7.2.1p7), but are allowed in
740  // C++.
741  if (Tok.is(tok::r_brace))
742    Diag(Tok, diag::ext_empty_struct_union_enum,
743         DeclSpec::getSpecifierName((DeclSpec::TST)TagType));
744
745  llvm::SmallVector<DeclTy*, 32> FieldDecls;
746
747  // While we still have something to read, read the declarations in the struct.
748  while (Tok.isNot(tok::r_brace) && Tok.isNot(tok::eof)) {
749    // Each iteration of this loop reads one struct-declaration.
750
751    // Check for extraneous top-level semicolon.
752    if (Tok.is(tok::semi)) {
753      Diag(Tok, diag::ext_extra_struct_semi);
754      ConsumeToken();
755      continue;
756    }
757    ParseStructDeclaration(TagDecl, FieldDecls);
758
759    if (Tok.is(tok::semi)) {
760      ConsumeToken();
761    } else if (Tok.is(tok::r_brace)) {
762      Diag(Tok.getLocation(), diag::ext_expected_semi_decl_list);
763      break;
764    } else {
765      Diag(Tok, diag::err_expected_semi_decl_list);
766      // Skip to end of block or statement
767      SkipUntil(tok::r_brace, true, true);
768    }
769  }
770
771  SourceLocation RBraceLoc = MatchRHSPunctuation(tok::r_brace, LBraceLoc);
772
773  Actions.ActOnFields(CurScope,
774                      RecordLoc,TagDecl,&FieldDecls[0],FieldDecls.size(),
775                      LBraceLoc, RBraceLoc);
776
777  AttributeList *AttrList = 0;
778  // If attributes exist after struct contents, parse them.
779  if (Tok.is(tok::kw___attribute))
780    AttrList = ParseAttributes(); // FIXME: where should I put them?
781}
782
783
784/// ParseEnumSpecifier
785///       enum-specifier: [C99 6.7.2.2]
786///         'enum' identifier[opt] '{' enumerator-list '}'
787/// [C99]   'enum' identifier[opt] '{' enumerator-list ',' '}'
788/// [GNU]   'enum' attributes[opt] identifier[opt] '{' enumerator-list ',' [opt]
789///                                                 '}' attributes[opt]
790///         'enum' identifier
791/// [GNU]   'enum' attributes[opt] identifier
792void Parser::ParseEnumSpecifier(DeclSpec &DS) {
793  assert(Tok.is(tok::kw_enum) && "Not an enum specifier");
794  SourceLocation StartLoc = ConsumeToken();
795
796  // Parse the tag portion of this.
797  DeclTy *TagDecl;
798  if (ParseTag(TagDecl, DeclSpec::TST_enum, StartLoc))
799    return;
800
801  if (Tok.is(tok::l_brace))
802    ParseEnumBody(StartLoc, TagDecl);
803
804  // TODO: semantic analysis on the declspec for enums.
805  const char *PrevSpec = 0;
806  if (DS.SetTypeSpecType(DeclSpec::TST_enum, StartLoc, PrevSpec, TagDecl))
807    Diag(StartLoc, diag::err_invalid_decl_spec_combination, PrevSpec);
808}
809
810/// ParseEnumBody - Parse a {} enclosed enumerator-list.
811///       enumerator-list:
812///         enumerator
813///         enumerator-list ',' enumerator
814///       enumerator:
815///         enumeration-constant
816///         enumeration-constant '=' constant-expression
817///       enumeration-constant:
818///         identifier
819///
820void Parser::ParseEnumBody(SourceLocation StartLoc, DeclTy *EnumDecl) {
821  SourceLocation LBraceLoc = ConsumeBrace();
822
823  // C does not allow an empty enumerator-list, C++ does [dcl.enum].
824  if (Tok.is(tok::r_brace) && !getLang().CPlusPlus)
825    Diag(Tok, diag::ext_empty_struct_union_enum, "enum");
826
827  llvm::SmallVector<DeclTy*, 32> EnumConstantDecls;
828
829  DeclTy *LastEnumConstDecl = 0;
830
831  // Parse the enumerator-list.
832  while (Tok.is(tok::identifier)) {
833    IdentifierInfo *Ident = Tok.getIdentifierInfo();
834    SourceLocation IdentLoc = ConsumeToken();
835
836    SourceLocation EqualLoc;
837    ExprTy *AssignedVal = 0;
838    if (Tok.is(tok::equal)) {
839      EqualLoc = ConsumeToken();
840      ExprResult Res = ParseConstantExpression();
841      if (Res.isInvalid)
842        SkipUntil(tok::comma, tok::r_brace, true, true);
843      else
844        AssignedVal = Res.Val;
845    }
846
847    // Install the enumerator constant into EnumDecl.
848    DeclTy *EnumConstDecl = Actions.ActOnEnumConstant(CurScope, EnumDecl,
849                                                      LastEnumConstDecl,
850                                                      IdentLoc, Ident,
851                                                      EqualLoc, AssignedVal);
852    EnumConstantDecls.push_back(EnumConstDecl);
853    LastEnumConstDecl = EnumConstDecl;
854
855    if (Tok.isNot(tok::comma))
856      break;
857    SourceLocation CommaLoc = ConsumeToken();
858
859    if (Tok.isNot(tok::identifier) && !getLang().C99)
860      Diag(CommaLoc, diag::ext_c99_enumerator_list_comma);
861  }
862
863  // Eat the }.
864  MatchRHSPunctuation(tok::r_brace, LBraceLoc);
865
866  Actions.ActOnEnumBody(StartLoc, EnumDecl, &EnumConstantDecls[0],
867                        EnumConstantDecls.size());
868
869  DeclTy *AttrList = 0;
870  // If attributes exist after the identifier list, parse them.
871  if (Tok.is(tok::kw___attribute))
872    AttrList = ParseAttributes(); // FIXME: where do they do?
873}
874
875/// isTypeSpecifierQualifier - Return true if the current token could be the
876/// start of a type-qualifier-list.
877bool Parser::isTypeQualifier() const {
878  switch (Tok.getKind()) {
879  default: return false;
880    // type-qualifier
881  case tok::kw_const:
882  case tok::kw_volatile:
883  case tok::kw_restrict:
884    return true;
885  }
886}
887
888/// isTypeSpecifierQualifier - Return true if the current token could be the
889/// start of a specifier-qualifier-list.
890bool Parser::isTypeSpecifierQualifier() const {
891  switch (Tok.getKind()) {
892  default: return false;
893    // GNU attributes support.
894  case tok::kw___attribute:
895    // GNU typeof support.
896  case tok::kw_typeof:
897
898    // type-specifiers
899  case tok::kw_short:
900  case tok::kw_long:
901  case tok::kw_signed:
902  case tok::kw_unsigned:
903  case tok::kw__Complex:
904  case tok::kw__Imaginary:
905  case tok::kw_void:
906  case tok::kw_char:
907  case tok::kw_int:
908  case tok::kw_float:
909  case tok::kw_double:
910  case tok::kw_bool:
911  case tok::kw__Bool:
912  case tok::kw__Decimal32:
913  case tok::kw__Decimal64:
914  case tok::kw__Decimal128:
915
916    // struct-or-union-specifier
917  case tok::kw_struct:
918  case tok::kw_union:
919    // enum-specifier
920  case tok::kw_enum:
921
922    // type-qualifier
923  case tok::kw_const:
924  case tok::kw_volatile:
925  case tok::kw_restrict:
926    return true;
927
928    // typedef-name
929  case tok::identifier:
930    return Actions.isTypeName(*Tok.getIdentifierInfo(), CurScope) != 0;
931  }
932}
933
934/// isDeclarationSpecifier() - Return true if the current token is part of a
935/// declaration specifier.
936bool Parser::isDeclarationSpecifier() const {
937  switch (Tok.getKind()) {
938  default: return false;
939    // storage-class-specifier
940  case tok::kw_typedef:
941  case tok::kw_extern:
942  case tok::kw___private_extern__:
943  case tok::kw_static:
944  case tok::kw_auto:
945  case tok::kw_register:
946  case tok::kw___thread:
947
948    // type-specifiers
949  case tok::kw_short:
950  case tok::kw_long:
951  case tok::kw_signed:
952  case tok::kw_unsigned:
953  case tok::kw__Complex:
954  case tok::kw__Imaginary:
955  case tok::kw_void:
956  case tok::kw_char:
957  case tok::kw_int:
958  case tok::kw_float:
959  case tok::kw_double:
960  case tok::kw_bool:
961  case tok::kw__Bool:
962  case tok::kw__Decimal32:
963  case tok::kw__Decimal64:
964  case tok::kw__Decimal128:
965
966    // struct-or-union-specifier
967  case tok::kw_struct:
968  case tok::kw_union:
969    // enum-specifier
970  case tok::kw_enum:
971
972    // type-qualifier
973  case tok::kw_const:
974  case tok::kw_volatile:
975  case tok::kw_restrict:
976
977    // function-specifier
978  case tok::kw_inline:
979
980    // GNU typeof support.
981  case tok::kw_typeof:
982
983    // GNU attributes.
984  case tok::kw___attribute:
985    return true;
986
987    // typedef-name
988  case tok::identifier:
989    return Actions.isTypeName(*Tok.getIdentifierInfo(), CurScope) != 0;
990  }
991}
992
993
994/// ParseTypeQualifierListOpt
995///       type-qualifier-list: [C99 6.7.5]
996///         type-qualifier
997/// [GNU]   attributes
998///         type-qualifier-list type-qualifier
999/// [GNU]   type-qualifier-list attributes
1000///
1001void Parser::ParseTypeQualifierListOpt(DeclSpec &DS) {
1002  while (1) {
1003    int isInvalid = false;
1004    const char *PrevSpec = 0;
1005    SourceLocation Loc = Tok.getLocation();
1006
1007    switch (Tok.getKind()) {
1008    default:
1009      // If this is not a type-qualifier token, we're done reading type
1010      // qualifiers.  First verify that DeclSpec's are consistent.
1011      DS.Finish(Diags, PP.getSourceManager(), getLang());
1012      return;
1013    case tok::kw_const:
1014      isInvalid = DS.SetTypeQual(DeclSpec::TQ_const   , Loc, PrevSpec,
1015                                 getLang())*2;
1016      break;
1017    case tok::kw_volatile:
1018      isInvalid = DS.SetTypeQual(DeclSpec::TQ_volatile, Loc, PrevSpec,
1019                                 getLang())*2;
1020      break;
1021    case tok::kw_restrict:
1022      isInvalid = DS.SetTypeQual(DeclSpec::TQ_restrict, Loc, PrevSpec,
1023                                 getLang())*2;
1024      break;
1025    case tok::kw___attribute:
1026      DS.AddAttributes(ParseAttributes());
1027      continue; // do *not* consume the next token!
1028    }
1029
1030    // If the specifier combination wasn't legal, issue a diagnostic.
1031    if (isInvalid) {
1032      assert(PrevSpec && "Method did not return previous specifier!");
1033      if (isInvalid == 1)  // Error.
1034        Diag(Tok, diag::err_invalid_decl_spec_combination, PrevSpec);
1035      else                 // extwarn.
1036        Diag(Tok, diag::ext_duplicate_declspec, PrevSpec);
1037    }
1038    ConsumeToken();
1039  }
1040}
1041
1042
1043/// ParseDeclarator - Parse and verify a newly-initialized declarator.
1044///
1045void Parser::ParseDeclarator(Declarator &D) {
1046  /// This implements the 'declarator' production in the C grammar, then checks
1047  /// for well-formedness and issues diagnostics.
1048  ParseDeclaratorInternal(D);
1049}
1050
1051/// ParseDeclaratorInternal
1052///       declarator: [C99 6.7.5]
1053///         pointer[opt] direct-declarator
1054/// [C++]   '&' declarator [C++ 8p4, dcl.decl]
1055/// [GNU]   '&' restrict[opt] attributes[opt] declarator
1056///
1057///       pointer: [C99 6.7.5]
1058///         '*' type-qualifier-list[opt]
1059///         '*' type-qualifier-list[opt] pointer
1060///
1061void Parser::ParseDeclaratorInternal(Declarator &D) {
1062  tok::TokenKind Kind = Tok.getKind();
1063
1064  // Not a pointer or C++ reference.
1065  if (Kind != tok::star && (Kind != tok::amp || !getLang().CPlusPlus))
1066    return ParseDirectDeclarator(D);
1067
1068  // Otherwise, '*' -> pointer or '&' -> reference.
1069  SourceLocation Loc = ConsumeToken();  // Eat the * or &.
1070
1071  if (Kind == tok::star) {
1072    // Is a pointer.
1073    DeclSpec DS;
1074
1075    ParseTypeQualifierListOpt(DS);
1076
1077    // Recursively parse the declarator.
1078    ParseDeclaratorInternal(D);
1079
1080    // Remember that we parsed a pointer type, and remember the type-quals.
1081    D.AddTypeInfo(DeclaratorChunk::getPointer(DS.getTypeQualifiers(), Loc,
1082                                              DS.TakeAttributes()));
1083  } else {
1084    // Is a reference
1085    DeclSpec DS;
1086
1087    // C++ 8.3.2p1: cv-qualified references are ill-formed except when the
1088    // cv-qualifiers are introduced through the use of a typedef or of a
1089    // template type argument, in which case the cv-qualifiers are ignored.
1090    //
1091    // [GNU] Retricted references are allowed.
1092    // [GNU] Attributes on references are allowed.
1093    ParseTypeQualifierListOpt(DS);
1094
1095    if (DS.getTypeQualifiers() != DeclSpec::TQ_unspecified) {
1096      if (DS.getTypeQualifiers() & DeclSpec::TQ_const)
1097        Diag(DS.getConstSpecLoc(),
1098             diag::err_invalid_reference_qualifier_application,
1099             "const");
1100      if (DS.getTypeQualifiers() & DeclSpec::TQ_volatile)
1101        Diag(DS.getVolatileSpecLoc(),
1102             diag::err_invalid_reference_qualifier_application,
1103             "volatile");
1104    }
1105
1106    // Recursively parse the declarator.
1107    ParseDeclaratorInternal(D);
1108
1109    // Remember that we parsed a reference type. It doesn't have type-quals.
1110    D.AddTypeInfo(DeclaratorChunk::getReference(DS.getTypeQualifiers(), Loc,
1111                                                DS.TakeAttributes()));
1112  }
1113}
1114
1115/// ParseDirectDeclarator
1116///       direct-declarator: [C99 6.7.5]
1117///         identifier
1118///         '(' declarator ')'
1119/// [GNU]   '(' attributes declarator ')'
1120/// [C90]   direct-declarator '[' constant-expression[opt] ']'
1121/// [C99]   direct-declarator '[' type-qual-list[opt] assignment-expr[opt] ']'
1122/// [C99]   direct-declarator '[' 'static' type-qual-list[opt] assign-expr ']'
1123/// [C99]   direct-declarator '[' type-qual-list 'static' assignment-expr ']'
1124/// [C99]   direct-declarator '[' type-qual-list[opt] '*' ']'
1125///         direct-declarator '(' parameter-type-list ')'
1126///         direct-declarator '(' identifier-list[opt] ')'
1127/// [GNU]   direct-declarator '(' parameter-forward-declarations
1128///                    parameter-type-list[opt] ')'
1129///
1130void Parser::ParseDirectDeclarator(Declarator &D) {
1131  // Parse the first direct-declarator seen.
1132  if (Tok.is(tok::identifier) && D.mayHaveIdentifier()) {
1133    assert(Tok.getIdentifierInfo() && "Not an identifier?");
1134    D.SetIdentifier(Tok.getIdentifierInfo(), Tok.getLocation());
1135    ConsumeToken();
1136  } else if (Tok.is(tok::l_paren)) {
1137    // direct-declarator: '(' declarator ')'
1138    // direct-declarator: '(' attributes declarator ')'
1139    // Example: 'char (*X)'   or 'int (*XX)(void)'
1140    ParseParenDeclarator(D);
1141  } else if (D.mayOmitIdentifier()) {
1142    // This could be something simple like "int" (in which case the declarator
1143    // portion is empty), if an abstract-declarator is allowed.
1144    D.SetIdentifier(0, Tok.getLocation());
1145  } else {
1146    // Expected identifier or '('.
1147    Diag(Tok, diag::err_expected_ident_lparen);
1148    D.SetIdentifier(0, Tok.getLocation());
1149  }
1150
1151  assert(D.isPastIdentifier() &&
1152         "Haven't past the location of the identifier yet?");
1153
1154  while (1) {
1155    if (Tok.is(tok::l_paren)) {
1156      ParseFunctionDeclarator(ConsumeParen(), D);
1157    } else if (Tok.is(tok::l_square)) {
1158      ParseBracketDeclarator(D);
1159    } else {
1160      break;
1161    }
1162  }
1163}
1164
1165/// ParseParenDeclarator - We parsed the declarator D up to a paren.  This is
1166/// only called before the identifier, so these are most likely just grouping
1167/// parens for precedence.  If we find that these are actually function
1168/// parameter parens in an abstract-declarator, we call ParseFunctionDeclarator.
1169///
1170///       direct-declarator:
1171///         '(' declarator ')'
1172/// [GNU]   '(' attributes declarator ')'
1173///
1174void Parser::ParseParenDeclarator(Declarator &D) {
1175  SourceLocation StartLoc = ConsumeParen();
1176  assert(!D.isPastIdentifier() && "Should be called before passing identifier");
1177
1178  // If we haven't past the identifier yet (or where the identifier would be
1179  // stored, if this is an abstract declarator), then this is probably just
1180  // grouping parens. However, if this could be an abstract-declarator, then
1181  // this could also be the start of function arguments (consider 'void()').
1182  bool isGrouping;
1183
1184  if (!D.mayOmitIdentifier()) {
1185    // If this can't be an abstract-declarator, this *must* be a grouping
1186    // paren, because we haven't seen the identifier yet.
1187    isGrouping = true;
1188  } else if (Tok.is(tok::r_paren) ||           // 'int()' is a function.
1189             isDeclarationSpecifier()) {       // 'int(int)' is a function.
1190    // This handles C99 6.7.5.3p11: in "typedef int X; void foo(X)", X is
1191    // considered to be a type, not a K&R identifier-list.
1192    isGrouping = false;
1193  } else {
1194    // Otherwise, this is a grouping paren, e.g. 'int (*X)' or 'int(X)'.
1195    isGrouping = true;
1196  }
1197
1198  // If this is a grouping paren, handle:
1199  // direct-declarator: '(' declarator ')'
1200  // direct-declarator: '(' attributes declarator ')'
1201  if (isGrouping) {
1202    if (Tok.is(tok::kw___attribute))
1203      D.AddAttributes(ParseAttributes());
1204
1205    ParseDeclaratorInternal(D);
1206    // Match the ')'.
1207    MatchRHSPunctuation(tok::r_paren, StartLoc);
1208    return;
1209  }
1210
1211  // Okay, if this wasn't a grouping paren, it must be the start of a function
1212  // argument list.  Recognize that this declarator will never have an
1213  // identifier (and remember where it would have been), then fall through to
1214  // the handling of argument lists.
1215  D.SetIdentifier(0, Tok.getLocation());
1216
1217  ParseFunctionDeclarator(StartLoc, D);
1218}
1219
1220/// ParseFunctionDeclarator - We are after the identifier and have parsed the
1221/// declarator D up to a paren, which indicates that we are parsing function
1222/// arguments.
1223///
1224/// This method also handles this portion of the grammar:
1225///       parameter-type-list: [C99 6.7.5]
1226///         parameter-list
1227///         parameter-list ',' '...'
1228///
1229///       parameter-list: [C99 6.7.5]
1230///         parameter-declaration
1231///         parameter-list ',' parameter-declaration
1232///
1233///       parameter-declaration: [C99 6.7.5]
1234///         declaration-specifiers declarator
1235/// [GNU]   declaration-specifiers declarator attributes
1236///         declaration-specifiers abstract-declarator[opt]
1237/// [GNU]   declaration-specifiers abstract-declarator[opt] attributes
1238///
1239void Parser::ParseFunctionDeclarator(SourceLocation LParenLoc, Declarator &D) {
1240  // lparen is already consumed!
1241  assert(D.isPastIdentifier() && "Should not call before identifier!");
1242
1243  // Okay, this is the parameter list of a function definition, or it is an
1244  // identifier list of a K&R-style function.
1245
1246  if (Tok.is(tok::r_paren)) {
1247    // Remember that we parsed a function type, and remember the attributes.
1248    // int() -> no prototype, no '...'.
1249    D.AddTypeInfo(DeclaratorChunk::getFunction(/*prototype*/ false,
1250                                               /*variadic*/ false,
1251                                               /*arglist*/ 0, 0, LParenLoc));
1252
1253    ConsumeParen();  // Eat the closing ')'.
1254    return;
1255  } else if (Tok.is(tok::identifier) &&
1256             // K&R identifier lists can't have typedefs as identifiers, per
1257             // C99 6.7.5.3p11.
1258             !Actions.isTypeName(*Tok.getIdentifierInfo(), CurScope)) {
1259    // Identifier list.  Note that '(' identifier-list ')' is only allowed for
1260    // normal declarators, not for abstract-declarators.
1261    return ParseFunctionDeclaratorIdentifierList(LParenLoc, D);
1262  }
1263
1264  // Finally, a normal, non-empty parameter type list.
1265
1266  // Build up an array of information about the parsed arguments.
1267  llvm::SmallVector<DeclaratorChunk::ParamInfo, 16> ParamInfo;
1268  llvm::SmallSet<const IdentifierInfo*, 16> ParamsSoFar;
1269
1270  // Enter function-declaration scope, limiting any declarators for struct
1271  // tags to the function prototype scope.
1272  // FIXME: is this needed?
1273  EnterScope(Scope::DeclScope);
1274
1275  bool IsVariadic = false;
1276  while (1) {
1277    if (Tok.is(tok::ellipsis)) {
1278      IsVariadic = true;
1279
1280      // Check to see if this is "void(...)" which is not allowed.
1281      if (ParamInfo.empty()) {
1282        // Otherwise, parse parameter type list.  If it starts with an
1283        // ellipsis,  diagnose the malformed function.
1284        Diag(Tok, diag::err_ellipsis_first_arg);
1285        IsVariadic = false;       // Treat this like 'void()'.
1286      }
1287
1288      ConsumeToken();     // Consume the ellipsis.
1289      break;
1290    }
1291
1292    SourceLocation DSStart = Tok.getLocation();
1293
1294    // Parse the declaration-specifiers.
1295    DeclSpec DS;
1296    ParseDeclarationSpecifiers(DS);
1297
1298    // Parse the declarator.  This is "PrototypeContext", because we must
1299    // accept either 'declarator' or 'abstract-declarator' here.
1300    Declarator ParmDecl(DS, Declarator::PrototypeContext);
1301    ParseDeclarator(ParmDecl);
1302
1303    // Parse GNU attributes, if present.
1304    if (Tok.is(tok::kw___attribute))
1305      ParmDecl.AddAttributes(ParseAttributes());
1306
1307    // Verify C99 6.7.5.3p2: The only SCS allowed is 'register'.
1308    if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified &&
1309        DS.getStorageClassSpec() != DeclSpec::SCS_register) {
1310      Diag(DS.getStorageClassSpecLoc(),
1311           diag::err_invalid_storage_class_in_func_decl);
1312      DS.ClearStorageClassSpecs();
1313    }
1314    if (DS.isThreadSpecified()) {
1315      Diag(DS.getThreadSpecLoc(),
1316           diag::err_invalid_storage_class_in_func_decl);
1317      DS.ClearStorageClassSpecs();
1318    }
1319
1320    // Remember this parsed parameter in ParamInfo.
1321    IdentifierInfo *ParmII = ParmDecl.getIdentifier();
1322
1323    // Verify that the argument identifier has not already been mentioned.
1324    if (ParmII && !ParamsSoFar.insert(ParmII)) {
1325      Diag(ParmDecl.getIdentifierLoc(), diag::err_param_redefinition,
1326           ParmII->getName());
1327      ParmII = 0;
1328      ParmDecl.setInvalidType(true);
1329    }
1330
1331    // If no parameter was specified, verify that *something* was specified,
1332    // otherwise we have a missing type and identifier.
1333    if (DS.getParsedSpecifiers() == DeclSpec::PQ_None &&
1334        ParmDecl.getIdentifier() == 0 && ParmDecl.getNumTypeObjects() == 0) {
1335      // Completely missing, emit error.
1336      Diag(DSStart, diag::err_missing_param);
1337    } else {
1338      // Otherwise, we have something.  Add it and let semantic analysis try
1339      // to grok it and add the result to the ParamInfo we are building.
1340
1341      // Inform the actions module about the parameter declarator, so it gets
1342      // added to the current scope.
1343      Action::TypeResult ParamTy =
1344        Actions.ActOnParamDeclaratorType(CurScope, ParmDecl);
1345
1346      ParamInfo.push_back(DeclaratorChunk::ParamInfo(ParmII,
1347          ParmDecl.getIdentifierLoc(), ParamTy.Val, ParmDecl.getInvalidType(),
1348          ParmDecl.getDeclSpec().TakeAttributes()));
1349    }
1350
1351    // If the next token is a comma, consume it and keep reading arguments.
1352    if (Tok.isNot(tok::comma)) break;
1353
1354    // Consume the comma.
1355    ConsumeToken();
1356  }
1357
1358  // Leave prototype scope.
1359  ExitScope();
1360
1361  // Remember that we parsed a function type, and remember the attributes.
1362  D.AddTypeInfo(DeclaratorChunk::getFunction(/*proto*/true, IsVariadic,
1363                                             &ParamInfo[0], ParamInfo.size(),
1364                                             LParenLoc));
1365
1366  // If we have the closing ')', eat it and we're done.
1367  MatchRHSPunctuation(tok::r_paren, LParenLoc);
1368}
1369
1370
1371/// ParseFunctionDeclaratorIdentifierList - While parsing a function declarator
1372/// we found a K&R-style identifier list instead of a type argument list.  The
1373/// current token is known to be the first identifier in the list.
1374///
1375///       identifier-list: [C99 6.7.5]
1376///         identifier
1377///         identifier-list ',' identifier
1378///
1379void Parser::ParseFunctionDeclaratorIdentifierList(SourceLocation LParenLoc,
1380                                                   Declarator &D) {
1381  // Build up an array of information about the parsed arguments.
1382  llvm::SmallVector<DeclaratorChunk::ParamInfo, 16> ParamInfo;
1383  llvm::SmallSet<const IdentifierInfo*, 16> ParamsSoFar;
1384
1385  // If there was no identifier specified for the declarator, either we are in
1386  // an abstract-declarator, or we are in a parameter declarator which was found
1387  // to be abstract.  In abstract-declarators, identifier lists are not valid:
1388  // diagnose this.
1389  if (!D.getIdentifier())
1390    Diag(Tok, diag::ext_ident_list_in_param);
1391
1392  // Tok is known to be the first identifier in the list.  Remember this
1393  // identifier in ParamInfo.
1394  ParamsSoFar.insert(Tok.getIdentifierInfo());
1395  ParamInfo.push_back(DeclaratorChunk::ParamInfo(Tok.getIdentifierInfo(),
1396                                                 Tok.getLocation(), 0));
1397
1398  ConsumeToken();  // eat the first identifier.
1399
1400  while (Tok.is(tok::comma)) {
1401    // Eat the comma.
1402    ConsumeToken();
1403
1404    // If this isn't an identifier, report the error and skip until ')'.
1405    if (Tok.isNot(tok::identifier)) {
1406      Diag(Tok, diag::err_expected_ident);
1407      SkipUntil(tok::r_paren);
1408      return;
1409    }
1410
1411    IdentifierInfo *ParmII = Tok.getIdentifierInfo();
1412
1413    // Reject 'typedef int y; int test(x, y)', but continue parsing.
1414    if (Actions.isTypeName(*ParmII, CurScope))
1415      Diag(Tok, diag::err_unexpected_typedef_ident, ParmII->getName());
1416
1417    // Verify that the argument identifier has not already been mentioned.
1418    if (!ParamsSoFar.insert(ParmII)) {
1419      Diag(Tok.getLocation(), diag::err_param_redefinition, ParmII->getName());
1420    } else {
1421      // Remember this identifier in ParamInfo.
1422      ParamInfo.push_back(DeclaratorChunk::ParamInfo(ParmII,
1423                                                     Tok.getLocation(), 0));
1424    }
1425
1426    // Eat the identifier.
1427    ConsumeToken();
1428  }
1429
1430  // Remember that we parsed a function type, and remember the attributes.  This
1431  // function type is always a K&R style function type, which is not varargs and
1432  // has no prototype.
1433  D.AddTypeInfo(DeclaratorChunk::getFunction(/*proto*/false, /*varargs*/false,
1434                                             &ParamInfo[0], ParamInfo.size(),
1435                                             LParenLoc));
1436
1437  // If we have the closing ')', eat it and we're done.
1438  MatchRHSPunctuation(tok::r_paren, LParenLoc);
1439}
1440
1441/// [C90]   direct-declarator '[' constant-expression[opt] ']'
1442/// [C99]   direct-declarator '[' type-qual-list[opt] assignment-expr[opt] ']'
1443/// [C99]   direct-declarator '[' 'static' type-qual-list[opt] assign-expr ']'
1444/// [C99]   direct-declarator '[' type-qual-list 'static' assignment-expr ']'
1445/// [C99]   direct-declarator '[' type-qual-list[opt] '*' ']'
1446void Parser::ParseBracketDeclarator(Declarator &D) {
1447  SourceLocation StartLoc = ConsumeBracket();
1448
1449  // If valid, this location is the position where we read the 'static' keyword.
1450  SourceLocation StaticLoc;
1451  if (Tok.is(tok::kw_static))
1452    StaticLoc = ConsumeToken();
1453
1454  // If there is a type-qualifier-list, read it now.
1455  DeclSpec DS;
1456  ParseTypeQualifierListOpt(DS);
1457
1458  // If we haven't already read 'static', check to see if there is one after the
1459  // type-qualifier-list.
1460  if (!StaticLoc.isValid() && Tok.is(tok::kw_static))
1461    StaticLoc = ConsumeToken();
1462
1463  // Handle "direct-declarator [ type-qual-list[opt] * ]".
1464  bool isStar = false;
1465  ExprResult NumElements(false);
1466
1467  // Handle the case where we have '[*]' as the array size.  However, a leading
1468  // star could be the start of an expression, for example 'X[*p + 4]'.  Verify
1469  // the the token after the star is a ']'.  Since stars in arrays are
1470  // infrequent, use of lookahead is not costly here.
1471  if (Tok.is(tok::star) && GetLookAheadToken(1).is(tok::r_square)) {
1472    ConsumeToken();  // Eat the '*'.
1473
1474    if (StaticLoc.isValid())
1475      Diag(StaticLoc, diag::err_unspecified_vla_size_with_static);
1476    StaticLoc = SourceLocation();  // Drop the static.
1477    isStar = true;
1478  } else if (Tok.isNot(tok::r_square)) {
1479    // Parse the assignment-expression now.
1480    NumElements = ParseAssignmentExpression();
1481  }
1482
1483  // If there was an error parsing the assignment-expression, recover.
1484  if (NumElements.isInvalid) {
1485    // If the expression was invalid, skip it.
1486    SkipUntil(tok::r_square);
1487    return;
1488  }
1489
1490  MatchRHSPunctuation(tok::r_square, StartLoc);
1491
1492  // If C99 isn't enabled, emit an ext-warn if the arg list wasn't empty and if
1493  // it was not a constant expression.
1494  if (!getLang().C99) {
1495    // TODO: check C90 array constant exprness.
1496    if (isStar || StaticLoc.isValid() ||
1497        0/*TODO: NumElts is not a C90 constantexpr */)
1498      Diag(StartLoc, diag::ext_c99_array_usage);
1499  }
1500
1501  // Remember that we parsed a pointer type, and remember the type-quals.
1502  D.AddTypeInfo(DeclaratorChunk::getArray(DS.getTypeQualifiers(),
1503                                          StaticLoc.isValid(), isStar,
1504                                          NumElements.Val, StartLoc));
1505}
1506
1507/// [GNU] typeof-specifier:
1508///         typeof ( expressions )
1509///         typeof ( type-name )
1510///
1511void Parser::ParseTypeofSpecifier(DeclSpec &DS) {
1512  assert(Tok.is(tok::kw_typeof) && "Not a typeof specifier");
1513  const IdentifierInfo *BuiltinII = Tok.getIdentifierInfo();
1514  SourceLocation StartLoc = ConsumeToken();
1515
1516  if (Tok.isNot(tok::l_paren)) {
1517    Diag(Tok, diag::err_expected_lparen_after, BuiltinII->getName());
1518    return;
1519  }
1520  SourceLocation LParenLoc = ConsumeParen(), RParenLoc;
1521
1522  if (isTypeSpecifierQualifier()) {
1523    TypeTy *Ty = ParseTypeName();
1524
1525    assert(Ty && "Parser::ParseTypeofSpecifier(): missing type");
1526
1527    if (Tok.isNot(tok::r_paren)) {
1528      MatchRHSPunctuation(tok::r_paren, LParenLoc);
1529      return;
1530    }
1531    RParenLoc = ConsumeParen();
1532    const char *PrevSpec = 0;
1533    // Check for duplicate type specifiers (e.g. "int typeof(int)").
1534    if (DS.SetTypeSpecType(DeclSpec::TST_typeofType, StartLoc, PrevSpec, Ty))
1535      Diag(StartLoc, diag::err_invalid_decl_spec_combination, PrevSpec);
1536  } else { // we have an expression.
1537    ExprResult Result = ParseExpression();
1538
1539    if (Result.isInvalid || Tok.isNot(tok::r_paren)) {
1540      MatchRHSPunctuation(tok::r_paren, LParenLoc);
1541      return;
1542    }
1543    RParenLoc = ConsumeParen();
1544    const char *PrevSpec = 0;
1545    // Check for duplicate type specifiers (e.g. "int typeof(int)").
1546    if (DS.SetTypeSpecType(DeclSpec::TST_typeofExpr, StartLoc, PrevSpec,
1547                           Result.Val))
1548      Diag(StartLoc, diag::err_invalid_decl_spec_combination, PrevSpec);
1549  }
1550}
1551
1552