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Chris Lattner697e5d62006-11-09 06:32:27 +00001//===--- SemaDecl.cpp - Semantic Analysis for Declarations ----------------===//
2//
3// The LLVM Compiler Infrastructure
4//
5// This file was developed by Chris Lattner and is distributed under
6// the University of Illinois Open Source License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file implements semantic analysis for declarations.
11//
12//===----------------------------------------------------------------------===//
13
Chris Lattnere168f762006-11-10 05:29:30 +000014#include "Sema.h"
Chris Lattner5c5fbcc2006-12-03 08:41:30 +000015#include "clang/AST/ASTContext.h"
Chris Lattnere168f762006-11-10 05:29:30 +000016#include "clang/AST/Decl.h"
Chris Lattner1300fb92007-01-23 23:42:53 +000017#include "clang/AST/Expr.h"
Chris Lattnerf84a79c2006-11-11 22:59:23 +000018#include "clang/AST/Type.h"
Chris Lattner591a6752006-11-19 23:16:18 +000019#include "clang/Parse/DeclSpec.h"
Chris Lattnere168f762006-11-10 05:29:30 +000020#include "clang/Parse/Scope.h"
21#include "clang/Lex/IdentifierTable.h"
Chris Lattnerac18be92006-11-20 06:49:47 +000022#include "clang/Basic/LangOptions.h"
Chris Lattner38047f92007-01-27 06:24:01 +000023#include "llvm/ADT/SmallSet.h"
Chris Lattner697e5d62006-11-09 06:32:27 +000024using namespace llvm;
25using namespace clang;
26
Chris Lattnere168f762006-11-10 05:29:30 +000027
Chris Lattner2ebe4bb2006-11-20 01:29:42 +000028Sema::DeclTy *Sema::isTypeName(const IdentifierInfo &II, Scope *S) const {
Chris Lattner32d920b2007-01-26 02:01:53 +000029 return dyn_cast_or_null<TypedefDecl>(II.getFETokenInfo<Decl>());
Chris Lattnere168f762006-11-10 05:29:30 +000030}
31
Chris Lattner302b4be2006-11-19 02:31:38 +000032void Sema::PopScope(SourceLocation Loc, Scope *S) {
33 for (Scope::decl_iterator I = S->decl_begin(), E = S->decl_end();
34 I != E; ++I) {
Chris Lattner99d31772007-01-21 22:37:37 +000035 Decl *D = static_cast<Decl*>(*I);
Chris Lattner302b4be2006-11-19 02:31:38 +000036 assert(D && "This decl didn't get pushed??");
Chris Lattnerff65b6b2007-01-23 01:33:16 +000037 IdentifierInfo *II = D->getIdentifier();
38 if (!II) continue;
Chris Lattner302b4be2006-11-19 02:31:38 +000039
Chris Lattnerff65b6b2007-01-23 01:33:16 +000040 // Unlink this decl from the identifier. Because the scope contains decls
41 // in an unordered collection, and because we have multiple identifier
42 // namespaces (e.g. tag, normal, label),the decl may not be the first entry.
43 if (II->getFETokenInfo<Decl>() == D) {
44 // Normal case, no multiple decls in different namespaces.
45 II->setFETokenInfo(D->getNext());
46 } else {
47 // Scan ahead. There are only three namespaces in C, so this loop can
48 // never execute more than 3 times.
49 Decl *SomeDecl = II->getFETokenInfo<Decl>();
50 while (SomeDecl->getNext() != D) {
51 SomeDecl = SomeDecl->getNext();
52 assert(SomeDecl && "Didn't find this decl on its identifier's chain!");
53 }
54 SomeDecl->setNext(D->getNext());
55 }
Chris Lattner302b4be2006-11-19 02:31:38 +000056
Chris Lattner740b2f32006-11-21 01:32:20 +000057 // This will have to be revisited for C++: there we want to nest stuff in
58 // namespace decls etc. Even for C, we might want a top-level translation
59 // unit decl or something.
60 if (!CurFunctionDecl)
61 continue;
62
63 // Chain this decl to the containing function, it now owns the memory for
64 // the decl.
65 D->setNext(CurFunctionDecl->getDeclChain());
66 CurFunctionDecl->setDeclChain(D);
Chris Lattner302b4be2006-11-19 02:31:38 +000067 }
68}
69
Chris Lattner200bdc32006-11-19 02:43:37 +000070/// ParsedFreeStandingDeclSpec - This method is invoked when a declspec with
71/// no declarator (e.g. "struct foo;") is parsed.
72Sema::DeclTy *Sema::ParsedFreeStandingDeclSpec(Scope *S, DeclSpec &DS) {
73 // TODO: emit error on 'int;' or 'const enum foo;'.
74 // TODO: emit error on 'typedef int;'
75 // if (!DS.isMissingDeclaratorOk()) Diag(...);
76
Chris Lattner200bdc32006-11-19 02:43:37 +000077 return 0;
78}
79
Chris Lattner18b19622007-01-22 07:39:13 +000080/// LookupScopedDecl - Look up the inner-most declaration in the specified
81/// namespace.
82static Decl *LookupScopedDecl(IdentifierInfo *II, Decl::IdentifierNamespace NS){
83 if (II == 0) return 0;
84
85 // Scan up the scope chain looking for a decl that matches this identifier
86 // that is in the appropriate namespace. This search should not take long, as
87 // shadowing of names is uncommon, and deep shadowing is extremely uncommon.
88 for (Decl *D = II->getFETokenInfo<Decl>(); D; D = D->getNext())
89 if (D->getIdentifierNamespace() == NS)
90 return D;
91 return 0;
92}
93
Chris Lattner01564d92007-01-27 19:27:06 +000094/// MergeTypeDefDecl - We just parsed a typedef 'New' which has the same name
95/// and scope as a previous declaration 'Old'. Figure out how to resolve this
96/// situation, merging decls or emitting diagnostics as appropriate.
97///
Chris Lattnerc511efb2007-01-27 19:32:14 +000098TypedefDecl *Sema::MergeTypeDefDecl(TypedefDecl *New, Decl *OldD) {
99 // Verify the old decl was also a typedef.
100 TypedefDecl *Old = dyn_cast<TypedefDecl>(OldD);
101 if (!Old) {
102 Diag(New->getLocation(), diag::err_redefinition_different_kind,
103 New->getName());
104 Diag(OldD->getLocation(), diag::err_previous_definition);
105 return New;
106 }
107
Chris Lattner01564d92007-01-27 19:27:06 +0000108 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope.
109 // TODO: This is totally simplistic. It should handle merging functions
110 // together etc, merging extern int X; int X; ...
111 Diag(New->getLocation(), diag::err_redefinition, New->getName());
112 Diag(Old->getLocation(), diag::err_previous_definition);
113 return New;
114}
115
116/// MergeFunctionDecl - We just parsed a function 'New' which has the same name
117/// and scope as a previous declaration 'Old'. Figure out how to resolve this
118/// situation, merging decls or emitting diagnostics as appropriate.
119///
Chris Lattnerc511efb2007-01-27 19:32:14 +0000120FunctionDecl *Sema::MergeFunctionDecl(FunctionDecl *New, Decl *OldD) {
121 // Verify the old decl was also a function.
122 FunctionDecl *Old = dyn_cast<FunctionDecl>(OldD);
123 if (!Old) {
124 Diag(New->getLocation(), diag::err_redefinition_different_kind,
125 New->getName());
126 Diag(OldD->getLocation(), diag::err_previous_definition);
127 return New;
128 }
129
130 // This is not right, but it's a start. If 'Old' is a
131
132
Chris Lattner01564d92007-01-27 19:27:06 +0000133 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope.
134 // TODO: This is totally simplistic. It should handle merging functions
135 // together etc, merging extern int X; int X; ...
136 Diag(New->getLocation(), diag::err_redefinition, New->getName());
137 Diag(Old->getLocation(), diag::err_previous_definition);
138 return New;
139}
140
141/// MergeVarDecl - We just parsed a variable 'New' which has the same name
142/// and scope as a previous declaration 'Old'. Figure out how to resolve this
143/// situation, merging decls or emitting diagnostics as appropriate.
144///
Chris Lattnerc511efb2007-01-27 19:32:14 +0000145VarDecl *Sema::MergeVarDecl(VarDecl *New, Decl *OldD) {
146 // Verify the old decl was also a variable.
147 VarDecl *Old = dyn_cast<VarDecl>(OldD);
148 if (!Old) {
149 Diag(New->getLocation(), diag::err_redefinition_different_kind,
150 New->getName());
151 Diag(OldD->getLocation(), diag::err_previous_definition);
152 return New;
153 }
154
Chris Lattner01564d92007-01-27 19:27:06 +0000155 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope.
156 // TODO: This is totally simplistic. It should handle merging functions
157 // together etc, merging extern int X; int X; ...
158 Diag(New->getLocation(), diag::err_redefinition, New->getName());
159 Diag(Old->getLocation(), diag::err_previous_definition);
160 return New;
161}
162
Chris Lattner18b19622007-01-22 07:39:13 +0000163
Chris Lattnere168f762006-11-10 05:29:30 +0000164Action::DeclTy *
165Sema::ParseDeclarator(Scope *S, Declarator &D, ExprTy *Init,
166 DeclTy *LastInGroup) {
167 IdentifierInfo *II = D.getIdentifier();
Chris Lattner302b4be2006-11-19 02:31:38 +0000168
Chris Lattner01564d92007-01-27 19:27:06 +0000169 // See if this is a redefinition of a variable in the same scope.
170 Decl *PrevDecl = LookupScopedDecl(II, Decl::IDNS_Ordinary);
171 if (!S->isDeclScope(PrevDecl))
172 PrevDecl = 0; // If in outer scope, it isn't the same thing.
173
Chris Lattnere168f762006-11-10 05:29:30 +0000174 Decl *New;
Chris Lattner01a7c532007-01-25 23:09:03 +0000175 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) {
Chris Lattner01564d92007-01-27 19:27:06 +0000176 TypedefDecl *NewTD = ParseTypedefDecl(S, D);
177 if (!NewTD) return 0;
178
179 // Merge the decl with the existing one if appropriate.
180 if (PrevDecl) {
181 NewTD = MergeTypeDefDecl(NewTD, PrevDecl);
182 if (NewTD == 0) return 0;
183 }
184 New = NewTD;
Chris Lattner01a7c532007-01-25 23:09:03 +0000185 } else if (D.isFunctionDeclarator()) {
186 TypeRef R = GetTypeForDeclarator(D, S);
187 if (R.isNull()) return 0;
Chris Lattner01564d92007-01-27 19:27:06 +0000188
189 FunctionDecl *NewFD = new FunctionDecl(D.getIdentifierLoc(), II, R);
190
191 // Merge the decl with the existing one if appropriate.
192 if (PrevDecl) {
193 NewFD = MergeFunctionDecl(NewFD, PrevDecl);
194 if (NewFD == 0) return 0;
195 }
196 New = NewFD;
Chris Lattner01a7c532007-01-25 23:09:03 +0000197 } else {
198 TypeRef R = GetTypeForDeclarator(D, S);
199 if (R.isNull()) return 0;
Chris Lattner01564d92007-01-27 19:27:06 +0000200 VarDecl *NewVD = new VarDecl(D.getIdentifierLoc(), II, R);
201
202 // Merge the decl with the existing one if appropriate.
203 if (PrevDecl) {
204 NewVD = MergeVarDecl(NewVD, PrevDecl);
205 if (NewVD == 0) return 0;
206 }
207 New = NewVD;
Chris Lattner01a7c532007-01-25 23:09:03 +0000208 }
Chris Lattner302b4be2006-11-19 02:31:38 +0000209
210
Chris Lattnere168f762006-11-10 05:29:30 +0000211 // If this has an identifier, add it to the scope stack.
212 if (II) {
Chris Lattner18b19622007-01-22 07:39:13 +0000213 New->setNext(II->getFETokenInfo<Decl>());
Chris Lattnere168f762006-11-10 05:29:30 +0000214 II->setFETokenInfo(New);
Chris Lattner99d31772007-01-21 22:37:37 +0000215 S->AddDecl(New);
Chris Lattnere168f762006-11-10 05:29:30 +0000216 }
217
218 // If this is a top-level decl that is chained to some other (e.g. int A,B,C;)
219 // remember this in the LastInGroupList list.
220 if (LastInGroup && S->getParent() == 0)
221 LastInGroupList.push_back((Decl*)LastInGroup);
222
223 return New;
224}
225
Chris Lattnerc5cdf4d2007-01-21 07:42:07 +0000226VarDecl *
227Sema::ParseParamDeclarator(DeclaratorChunk &FTI, unsigned ArgNo,
228 Scope *FnScope) {
229 const DeclaratorChunk::ParamInfo &PI = FTI.Fun.ArgInfo[ArgNo];
Chris Lattner200bdc32006-11-19 02:43:37 +0000230
Chris Lattnerc5cdf4d2007-01-21 07:42:07 +0000231 IdentifierInfo *II = PI.Ident;
Chris Lattnerc284e9b2007-01-23 05:14:32 +0000232 // TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope.
233 // Can this happen for params? We already checked that they don't conflict
234 // among each other. Here they can only shadow globals, which is ok.
Chris Lattner18b19622007-01-22 07:39:13 +0000235 if (Decl *PrevDecl = LookupScopedDecl(II, Decl::IDNS_Ordinary)) {
Chris Lattnerc5cdf4d2007-01-21 07:42:07 +0000236
Chris Lattnerc5cdf4d2007-01-21 07:42:07 +0000237 }
238
Chris Lattner38047f92007-01-27 06:24:01 +0000239 VarDecl *New = new VarDecl(PI.IdentLoc, II,
240 TypeRef::getFromOpaquePtr(PI.TypeInfo));
Chris Lattnerc5cdf4d2007-01-21 07:42:07 +0000241
242 // If this has an identifier, add it to the scope stack.
243 if (II) {
Chris Lattner18b19622007-01-22 07:39:13 +0000244 New->setNext(II->getFETokenInfo<Decl>());
Chris Lattnerc5cdf4d2007-01-21 07:42:07 +0000245 II->setFETokenInfo(New);
Chris Lattner99d31772007-01-21 22:37:37 +0000246 FnScope->AddDecl(New);
Chris Lattnerc5cdf4d2007-01-21 07:42:07 +0000247 }
Chris Lattner229ce602006-11-21 01:21:07 +0000248
Chris Lattnerc5cdf4d2007-01-21 07:42:07 +0000249 return New;
250}
251
252
253Sema::DeclTy *Sema::ParseStartOfFunctionDef(Scope *FnBodyScope, Declarator &D) {
Chris Lattner229ce602006-11-21 01:21:07 +0000254 assert(CurFunctionDecl == 0 && "Function parsing confused");
Chris Lattner5c5fbcc2006-12-03 08:41:30 +0000255 assert(D.getTypeObject(0).Kind == DeclaratorChunk::Function &&
256 "Not a function declarator!");
257 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun;
258
259 // Verify 6.9.1p6: 'every identifier in the identifier list shall be declared'
260 // for a K&R function.
261 if (!FTI.hasPrototype) {
262 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) {
263 if (FTI.ArgInfo[i].TypeInfo == 0) {
264 Diag(FTI.ArgInfo[i].IdentLoc, diag::err_param_not_declared,
265 FTI.ArgInfo[i].Ident->getName());
266 // Implicitly declare the argument as type 'int' for lack of a better
267 // type.
268 FTI.ArgInfo[i].TypeInfo = Context.IntTy.getAsOpaquePtr();
269 }
270 }
271
272 // Since this is a function definition, act as though we have information
273 // about the arguments.
274 FTI.hasPrototype = true;
Chris Lattner2114d5e2006-12-04 07:40:24 +0000275 } else {
276 // FIXME: Diagnose arguments without names in C.
277
Chris Lattner5c5fbcc2006-12-03 08:41:30 +0000278 }
279
Chris Lattnerc5cdf4d2007-01-21 07:42:07 +0000280 Scope *GlobalScope = FnBodyScope->getParent();
281
282 FunctionDecl *FD =
283 static_cast<FunctionDecl*>(ParseDeclarator(GlobalScope, D, 0, 0));
Chris Lattner229ce602006-11-21 01:21:07 +0000284 CurFunctionDecl = FD;
Chris Lattner2114d5e2006-12-04 07:40:24 +0000285
Chris Lattnerc5cdf4d2007-01-21 07:42:07 +0000286 // Create Decl objects for each parameter, adding them to the FunctionDecl.
287 SmallVector<VarDecl*, 16> Params;
Chris Lattnerf61c8a82007-01-21 19:04:43 +0000288
289 // Check for C99 6.7.5.3p10 - foo(void) is a non-varargs function that takes
290 // no arguments, not a function that takes a single void argument.
291 if (FTI.NumArgs == 1 && !FTI.isVariadic && FTI.ArgInfo[0].Ident == 0 &&
292 FTI.ArgInfo[0].TypeInfo == Context.VoidTy.getAsOpaquePtr()) {
Chris Lattner99d31772007-01-21 22:37:37 +0000293 // empty arg list, don't push any params.
Chris Lattnerf61c8a82007-01-21 19:04:43 +0000294 } else {
295 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i)
296 Params.push_back(ParseParamDeclarator(D.getTypeObject(0), i,FnBodyScope));
297 }
Chris Lattner2114d5e2006-12-04 07:40:24 +0000298
Chris Lattnerc5cdf4d2007-01-21 07:42:07 +0000299 FD->setParams(&Params[0], Params.size());
Chris Lattner2114d5e2006-12-04 07:40:24 +0000300
Chris Lattnere168f762006-11-10 05:29:30 +0000301 return FD;
302}
303
Chris Lattner229ce602006-11-21 01:21:07 +0000304Sema::DeclTy *Sema::ParseFunctionDefBody(DeclTy *D, StmtTy *Body) {
305 FunctionDecl *FD = static_cast<FunctionDecl*>(D);
306 FD->setBody((Stmt*)Body);
307
308 assert(FD == CurFunctionDecl && "Function parsing confused");
309 CurFunctionDecl = 0;
310 return FD;
311}
312
313
Chris Lattnerac18be92006-11-20 06:49:47 +0000314/// ImplicitlyDefineFunction - An undeclared identifier was used in a function
315/// call, forming a call to an implicitly defined function (per C99 6.5.1p2).
316Decl *Sema::ImplicitlyDefineFunction(SourceLocation Loc, IdentifierInfo &II,
317 Scope *S) {
318 if (getLangOptions().C99) // Extension in C99.
319 Diag(Loc, diag::ext_implicit_function_decl, II.getName());
320 else // Legal in C90, but warn about it.
321 Diag(Loc, diag::warn_implicit_function_decl, II.getName());
322
323 // FIXME: handle stuff like:
324 // void foo() { extern float X(); }
325 // void bar() { X(); } <-- implicit decl for X in another scope.
326
327 // Set a Declarator for the implicit definition: int foo();
Chris Lattner353f5742006-11-28 04:50:12 +0000328 const char *Dummy;
Chris Lattnerac18be92006-11-20 06:49:47 +0000329 DeclSpec DS;
Chris Lattnerb20e8942006-11-28 05:30:29 +0000330 bool Error = DS.SetTypeSpecType(DeclSpec::TST_int, Loc, Dummy);
Chris Lattner353f5742006-11-28 04:50:12 +0000331 assert(!Error && "Error setting up implicit decl!");
Chris Lattnerac18be92006-11-20 06:49:47 +0000332 Declarator D(DS, Declarator::BlockContext);
Chris Lattnercbc426d2006-12-02 06:43:02 +0000333 D.AddTypeInfo(DeclaratorChunk::getFunction(false, false, 0, 0, Loc));
Chris Lattnerac18be92006-11-20 06:49:47 +0000334 D.SetIdentifier(&II, Loc);
335
336 Decl *Result = static_cast<Decl*>(ParseDeclarator(S, D, 0, 0));
337
338 // Visit this implicit declaration like any other top-level form.
339 LastInGroupList.push_back(Result);
340 return Result;
341}
342
Chris Lattner302b4be2006-11-19 02:31:38 +0000343
Chris Lattner01564d92007-01-27 19:27:06 +0000344TypedefDecl *Sema::ParseTypedefDecl(Scope *S, Declarator &D) {
Chris Lattnerda8aa7b2006-11-19 23:12:30 +0000345 assert(D.getIdentifier() && "Wrong callback for declspec withotu declarator");
Chris Lattner302b4be2006-11-19 02:31:38 +0000346
Chris Lattner5ca17df2006-11-19 23:32:49 +0000347 TypeRef T = GetTypeForDeclarator(D, S);
Chris Lattner0d8b1a12006-11-20 04:34:45 +0000348 if (T.isNull()) return 0;
349
Chris Lattner18b19622007-01-22 07:39:13 +0000350 // Scope manipulation handled by caller.
351 return new TypedefDecl(D.getIdentifierLoc(), D.getIdentifier(), T);
Chris Lattnere168f762006-11-10 05:29:30 +0000352}
353
Chris Lattner18b19622007-01-22 07:39:13 +0000354
Chris Lattner1300fb92007-01-23 23:42:53 +0000355/// ParseTag - This is invoked when we see 'struct foo' or 'struct {'. In the
356/// former case, Name will be non-null. In the later case, Name will be null.
357/// TagType indicates what kind of tag this is. TK indicates whether this is a
358/// reference/declaration/definition of a tag.
Chris Lattner7b9ace62007-01-23 20:11:08 +0000359Sema::DeclTy *Sema::ParseTag(Scope *S, unsigned TagType, TagKind TK,
Chris Lattnerf34c4da2007-01-23 04:08:05 +0000360 SourceLocation KWLoc, IdentifierInfo *Name,
361 SourceLocation NameLoc) {
Chris Lattner8799cf22007-01-23 01:57:16 +0000362 // If this is a use of an existing tag, it must have a name.
Chris Lattner7b9ace62007-01-23 20:11:08 +0000363 assert((Name != 0 || TK == TK_Definition) &&
364 "Nameless record must be a definition!");
Chris Lattner8799cf22007-01-23 01:57:16 +0000365
Chris Lattnerf34c4da2007-01-23 04:08:05 +0000366 Decl::Kind Kind;
Chris Lattnerbf0b7982007-01-23 04:27:41 +0000367 switch (TagType) {
Chris Lattnerf34c4da2007-01-23 04:08:05 +0000368 default: assert(0 && "Unknown tag type!");
Chris Lattnerbf0b7982007-01-23 04:27:41 +0000369 case DeclSpec::TST_struct: Kind = Decl::Struct; break;
370 case DeclSpec::TST_union: Kind = Decl::Union; break;
371//case DeclSpec::TST_class: Kind = Decl::Class; break;
372 case DeclSpec::TST_enum: Kind = Decl::Enum; break;
Chris Lattnerf34c4da2007-01-23 04:08:05 +0000373 }
Chris Lattner7e783a12007-01-23 02:05:42 +0000374
Chris Lattner18b19622007-01-22 07:39:13 +0000375 // If this is a named struct, check to see if there was a previous forward
376 // declaration or definition.
Chris Lattner7b9ace62007-01-23 20:11:08 +0000377 if (TagDecl *PrevDecl =
378 dyn_cast_or_null<TagDecl>(LookupScopedDecl(Name, Decl::IDNS_Tag))) {
Chris Lattner8799cf22007-01-23 01:57:16 +0000379
380 // If this is a use of a previous tag, or if the tag is already declared in
381 // the same scope (so that the definition/declaration completes or
382 // rementions the tag), reuse the decl.
Chris Lattner7b9ace62007-01-23 20:11:08 +0000383 if (TK == TK_Reference || S->isDeclScope(PrevDecl)) {
Chris Lattner7e783a12007-01-23 02:05:42 +0000384 // Make sure that this wasn't declared as an enum and now used as a struct
385 // or something similar.
386 if (PrevDecl->getKind() != Kind) {
Chris Lattnerf34c4da2007-01-23 04:08:05 +0000387 Diag(KWLoc, diag::err_use_with_wrong_tag, Name->getName());
Chris Lattner7e783a12007-01-23 02:05:42 +0000388 Diag(PrevDecl->getLocation(), diag::err_previous_use);
389 }
Chris Lattner7b9ace62007-01-23 20:11:08 +0000390
391 // If this is a use or a forward declaration, we're good.
392 if (TK != TK_Definition)
393 return PrevDecl;
Chris Lattnerf34c4da2007-01-23 04:08:05 +0000394
Chris Lattner7b9ace62007-01-23 20:11:08 +0000395 // Diagnose attempts to redefine a tag.
396 if (PrevDecl->isDefinition()) {
397 Diag(NameLoc, diag::err_redefinition, Name->getName());
398 Diag(PrevDecl->getLocation(), diag::err_previous_definition);
399 // If this is a redefinition, recover by making this struct be
400 // anonymous, which will make any later references get the previous
401 // definition.
402 Name = 0;
403 } else {
404 // Okay, this is definition of a previously declared or referenced tag.
405 // Move the location of the decl to be the definition site.
406 PrevDecl->setLocation(NameLoc);
Chris Lattner7b9ace62007-01-23 20:11:08 +0000407 return PrevDecl;
408 }
Chris Lattner8799cf22007-01-23 01:57:16 +0000409 }
Chris Lattnerf34c4da2007-01-23 04:08:05 +0000410 // If we get here, this is a definition of a new struct type in a nested
411 // scope, e.g. "struct foo; void bar() { struct foo; }", just create a new
412 // type.
Chris Lattner18b19622007-01-22 07:39:13 +0000413 }
414
Chris Lattnerbf0b7982007-01-23 04:27:41 +0000415 // If there is an identifier, use the location of the identifier as the
416 // location of the decl, otherwise use the location of the struct/union
417 // keyword.
418 SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc;
419
Chris Lattner18b19622007-01-22 07:39:13 +0000420 // Otherwise, if this is the first time we've seen this tag, create the decl.
Chris Lattner7b9ace62007-01-23 20:11:08 +0000421 TagDecl *New;
Chris Lattner720a0542007-01-25 00:44:24 +0000422 switch (Kind) {
423 default: assert(0 && "Unknown tag kind!");
Chris Lattner5f521502007-01-25 06:27:24 +0000424 case Decl::Enum:
425 New = new EnumDecl(Loc, Name);
426 // If this is an undefined enum, warn.
Chris Lattnerc1915e22007-01-25 07:29:02 +0000427 if (TK != TK_Definition) Diag(Loc, diag::ext_forward_ref_enum);
Chris Lattner5f521502007-01-25 06:27:24 +0000428 break;
Chris Lattner720a0542007-01-25 00:44:24 +0000429 case Decl::Union:
430 case Decl::Struct:
431 case Decl::Class:
Chris Lattnerf34c4da2007-01-23 04:08:05 +0000432 New = new RecordDecl(Kind, Loc, Name);
Chris Lattner720a0542007-01-25 00:44:24 +0000433 break;
434 }
Chris Lattner18b19622007-01-22 07:39:13 +0000435
436 // If this has an identifier, add it to the scope stack.
437 if (Name) {
438 New->setNext(Name->getFETokenInfo<Decl>());
439 Name->setFETokenInfo(New);
440 S->AddDecl(New);
441 }
442
443 return New;
444}
Chris Lattner1300fb92007-01-23 23:42:53 +0000445
446/// ParseField - Each field of a struct/union/class is passed into this in order
447/// to create a FieldDecl object for it.
448Sema::DeclTy *Sema::ParseField(Scope *S, DeclTy *TagDecl,
449 SourceLocation DeclStart,
450 Declarator &D, ExprTy *BitfieldWidth) {
451 IdentifierInfo *II = D.getIdentifier();
452 Expr *BitWidth = (Expr*)BitfieldWidth;
453
454 SourceLocation Loc = DeclStart;
455 if (II) Loc = D.getIdentifierLoc();
456
457 if (BitWidth) {
458 // TODO: Validate.
Chris Lattner01a7c532007-01-25 23:09:03 +0000459 printf("WARNING: BITFIELDS IGNORED!\n");
Chris Lattner1300fb92007-01-23 23:42:53 +0000460
461 // 6.7.2.1p3
462 // 6.7.2.1p4
463
464 } else {
465 // Not a bitfield.
466
467 // validate II.
468
469 }
470
Chris Lattner01a7c532007-01-25 23:09:03 +0000471 TypeRef T = GetTypeForDeclarator(D, S);
472 if (T.isNull()) return 0;
473
474 return new FieldDecl(Loc, II, T);
Chris Lattner1300fb92007-01-23 23:42:53 +0000475}
476
477void Sema::ParseRecordBody(SourceLocation RecLoc, DeclTy *RecDecl,
478 DeclTy **Fields, unsigned NumFields) {
Chris Lattnerc1915e22007-01-25 07:29:02 +0000479 RecordDecl *Record = cast<RecordDecl>(static_cast<Decl*>(RecDecl));
Chris Lattner1300fb92007-01-23 23:42:53 +0000480 if (Record->isDefinition()) {
481 // Diagnose code like:
Chris Lattnerbdf8b8d2007-01-24 02:11:17 +0000482 // struct S { struct S {} X; };
Chris Lattner1300fb92007-01-23 23:42:53 +0000483 // We discover this when we complete the outer S. Reject and ignore the
484 // outer S.
485 Diag(Record->getLocation(), diag::err_nested_redefinition,
486 Record->getKindName());
487 Diag(RecLoc, diag::err_previous_definition);
488 return;
489 }
Chris Lattnerbdf8b8d2007-01-24 02:11:17 +0000490
Chris Lattnerbdf8b8d2007-01-24 02:11:17 +0000491 // Verify that all the fields are okay.
Chris Lattner82625602007-01-24 02:26:21 +0000492 unsigned NumNamedMembers = 0;
Chris Lattner41943152007-01-25 04:52:46 +0000493 SmallVector<Decl*, 32> RecFields;
Chris Lattnere5a66562007-01-25 22:48:42 +0000494 SmallSet<const IdentifierInfo*, 32> FieldIDs;
495
Chris Lattnerbdf8b8d2007-01-24 02:11:17 +0000496 for (unsigned i = 0; i != NumFields; ++i) {
497 FieldDecl *FD = cast_or_null<FieldDecl>(static_cast<Decl*>(Fields[i]));
498 if (!FD) continue; // Already issued a diagnostic.
Chris Lattner720a0542007-01-25 00:44:24 +0000499
500 // Get the type for the field.
501 Type *FDTy = FD->getType()->getCanonicalType();
502
Chris Lattnerbdf8b8d2007-01-24 02:11:17 +0000503 // C99 6.7.2.1p2 - A field may not be a function type.
Chris Lattner720a0542007-01-25 00:44:24 +0000504 if (isa<FunctionType>(FDTy)) {
Chris Lattnerbdf8b8d2007-01-24 02:11:17 +0000505 Diag(FD->getLocation(), diag::err_field_declared_as_function,
506 FD->getName());
Chris Lattner82625602007-01-24 02:26:21 +0000507 delete FD;
Chris Lattnerbdf8b8d2007-01-24 02:11:17 +0000508 continue;
509 }
510
Chris Lattner82625602007-01-24 02:26:21 +0000511 // C99 6.7.2.1p2 - A field may not be an incomplete type except...
Chris Lattner720a0542007-01-25 00:44:24 +0000512 if (FDTy->isIncompleteType()) {
Chris Lattner82625602007-01-24 02:26:21 +0000513 if (i != NumFields-1 || // ... that the last member ...
514 Record->getKind() != Decl::Struct || // ... of a structure ...
Chris Lattner720a0542007-01-25 00:44:24 +0000515 !isa<ArrayType>(FDTy)) { //... may have incomplete array type.
Chris Lattner82625602007-01-24 02:26:21 +0000516 Diag(FD->getLocation(), diag::err_field_incomplete, FD->getName());
517 delete FD;
518 continue;
519 }
Chris Lattner720a0542007-01-25 00:44:24 +0000520 if (NumNamedMembers < 1) { //... must have more than named member ...
Chris Lattner82625602007-01-24 02:26:21 +0000521 Diag(FD->getLocation(), diag::err_flexible_array_empty_struct,
522 FD->getName());
523 delete FD;
524 continue;
525 }
Chris Lattner720a0542007-01-25 00:44:24 +0000526
527 // Okay, we have a legal flexible array member at the end of the struct.
Chris Lattner41943152007-01-25 04:52:46 +0000528 Record->setHasFlexibleArrayMember(true);
Chris Lattnerbdf8b8d2007-01-24 02:11:17 +0000529 }
Chris Lattner720a0542007-01-25 00:44:24 +0000530
531
532 /// C99 6.7.2.1p2 - a struct ending in a flexible array member cannot be the
533 /// field of another structure or the element of an array.
534 if (RecordType *FDTTy = dyn_cast<RecordType>(FDTy)) {
535 if (FDTTy->getDecl()->hasFlexibleArrayMember()) {
536 // If this is a member of a union, then entire union becomes "flexible".
537 if (Record->getKind() == Decl::Union) {
Chris Lattner41943152007-01-25 04:52:46 +0000538 Record->setHasFlexibleArrayMember(true);
Chris Lattner720a0542007-01-25 00:44:24 +0000539 } else {
540 // If this is a struct/class and this is not the last element, reject
541 // it. Note that GCC supports variable sized arrays in the middle of
542 // structures.
543 if (i != NumFields-1) {
544 Diag(FD->getLocation(), diag::err_variable_sized_type_in_struct,
545 FD->getName());
546 delete FD;
547 continue;
548 }
549
550 // We support flexible arrays at the end of structs in other structs
551 // as an extension.
552 Diag(FD->getLocation(), diag::ext_flexible_array_in_struct,
553 FD->getName());
Chris Lattner41943152007-01-25 04:52:46 +0000554 Record->setHasFlexibleArrayMember(true);
Chris Lattner720a0542007-01-25 00:44:24 +0000555 }
556 }
557 }
558
Chris Lattner82625602007-01-24 02:26:21 +0000559 // Keep track of the number of named members.
Chris Lattnere5a66562007-01-25 22:48:42 +0000560 if (IdentifierInfo *II = FD->getIdentifier()) {
561 // Detect duplicate member names.
Chris Lattnerbaf33662007-01-27 02:14:08 +0000562 if (!FieldIDs.insert(II)) {
Chris Lattnere5a66562007-01-25 22:48:42 +0000563 Diag(FD->getLocation(), diag::err_duplicate_member, II->getName());
564 // Find the previous decl.
565 SourceLocation PrevLoc;
566 for (unsigned i = 0, e = RecFields.size(); ; ++i) {
567 assert(i != e && "Didn't find previous def!");
568 if (RecFields[i]->getIdentifier() == II) {
569 PrevLoc = RecFields[i]->getLocation();
570 break;
571 }
572 }
573 Diag(PrevLoc, diag::err_previous_definition);
574 delete FD;
575 continue;
576 }
Chris Lattner82625602007-01-24 02:26:21 +0000577 ++NumNamedMembers;
Chris Lattnere5a66562007-01-25 22:48:42 +0000578 }
Chris Lattner41943152007-01-25 04:52:46 +0000579
580 // Remember good fields.
581 RecFields.push_back(FD);
Chris Lattnerbdf8b8d2007-01-24 02:11:17 +0000582 }
Chris Lattner82625602007-01-24 02:26:21 +0000583
584
585 // Okay, we successfully defined 'Record'.
Chris Lattner41943152007-01-25 04:52:46 +0000586 Record->defineBody(&RecFields[0], RecFields.size());
Chris Lattner1300fb92007-01-23 23:42:53 +0000587}
588
Chris Lattnerc1915e22007-01-25 07:29:02 +0000589Sema::DeclTy *Sema::ParseEnumConstant(Scope *S, DeclTy *EnumDeclX,
590 SourceLocation IdLoc, IdentifierInfo *Id,
591 SourceLocation EqualLoc, ExprTy *Val) {
592 EnumDecl *TheEnumDecl = cast<EnumDecl>(static_cast<Decl*>(EnumDeclX));
Chris Lattner8116d1b2007-01-25 22:38:29 +0000593
594 // Verify that there isn't already something declared with this name in this
595 // scope.
596 if (Decl *PrevDecl = LookupScopedDecl(Id, Decl::IDNS_Ordinary)) {
597 if (S->isDeclScope(PrevDecl)) {
598 if (isa<EnumConstantDecl>(PrevDecl))
599 Diag(IdLoc, diag::err_redefinition_of_enumerator, Id->getName());
600 else
601 Diag(IdLoc, diag::err_redefinition, Id->getName());
602 Diag(PrevDecl->getLocation(), diag::err_previous_definition);
603 return 0;
604 }
605 }
606
Chris Lattnerc1915e22007-01-25 07:29:02 +0000607 TypeRef Ty = Context.getTagDeclType(TheEnumDecl);
Chris Lattner8116d1b2007-01-25 22:38:29 +0000608 EnumConstantDecl *New = new EnumConstantDecl(IdLoc, Id, Ty);
609
610 // Register this decl in the current scope stack.
611 New->setNext(Id->getFETokenInfo<Decl>());
612 Id->setFETokenInfo(New);
613 S->AddDecl(New);
614 return New;
Chris Lattnerc1915e22007-01-25 07:29:02 +0000615}
616
617void Sema::ParseEnumBody(SourceLocation EnumLoc, DeclTy *EnumDeclX,
618 DeclTy **Elements, unsigned NumElements) {
619 EnumDecl *Enum = cast<EnumDecl>(static_cast<Decl*>(EnumDeclX));
620 assert(!Enum->isDefinition() && "Enum redefinitions can't reach here");
621
622 // Verify that all the values are okay.
623 SmallVector<EnumConstantDecl*, 32> Values;
624 for (unsigned i = 0; i != NumElements; ++i) {
625 EnumConstantDecl *ECD =
626 cast_or_null<EnumConstantDecl>(static_cast<Decl*>(Elements[i]));
627 if (!ECD) continue; // Already issued a diagnostic.
628
629 Values.push_back(ECD);
630 }
631
632 Enum->defineElements(&Values[0], Values.size());
633}
Chris Lattner1300fb92007-01-23 23:42:53 +0000634