1 //===--- SemaType.cpp - Semantic Analysis for Types -----------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements type-related semantic analysis.
12 //===----------------------------------------------------------------------===//
15 #include "clang/AST/ASTContext.h"
16 #include "clang/AST/Decl.h"
17 #include "clang/AST/DeclObjC.h"
18 #include "clang/Parse/DeclSpec.h"
19 #include "clang/Basic/LangOptions.h"
20 using namespace clang;
22 /// ConvertDeclSpecToType - Convert the specified declspec to the appropriate
23 /// type object. This returns null on error.
24 static QualType ConvertDeclSpecToType(const DeclSpec &DS, ASTContext &Ctx) {
25 // FIXME: Should move the logic from DeclSpec::Finish to here for validity
28 switch (DS.getTypeSpecType()) {
29 default: return QualType(); // FIXME: Handle unimp cases!
30 case DeclSpec::TST_void: return Ctx.VoidTy;
31 case DeclSpec::TST_char:
32 if (DS.getTypeSpecSign() == DeclSpec::TSS_unspecified)
34 else if (DS.getTypeSpecSign() == DeclSpec::TSS_signed)
35 return Ctx.SignedCharTy;
37 assert(DS.getTypeSpecSign() == DeclSpec::TSS_unsigned &&
39 return Ctx.UnsignedCharTy;
41 case DeclSpec::TST_unspecified: // Unspecific typespec defaults to int.
42 case DeclSpec::TST_int: {
44 if (DS.getTypeSpecSign() != DeclSpec::TSS_unsigned) {
45 switch (DS.getTypeSpecWidth()) {
46 case DeclSpec::TSW_unspecified: Result = Ctx.IntTy; break;
47 case DeclSpec::TSW_short: Result = Ctx.ShortTy; break;
48 case DeclSpec::TSW_long: Result = Ctx.LongTy; break;
49 case DeclSpec::TSW_longlong: Result = Ctx.LongLongTy; break;
52 switch (DS.getTypeSpecWidth()) {
53 case DeclSpec::TSW_unspecified: Result = Ctx.UnsignedIntTy; break;
54 case DeclSpec::TSW_short: Result = Ctx.UnsignedShortTy; break;
55 case DeclSpec::TSW_long: Result = Ctx.UnsignedLongTy; break;
56 case DeclSpec::TSW_longlong: Result = Ctx.UnsignedLongLongTy; break;
59 // Handle complex integer types.
60 if (DS.getTypeSpecComplex() == DeclSpec::TSC_unspecified)
62 assert(DS.getTypeSpecComplex() == DeclSpec::TSC_complex &&
63 "FIXME: imaginary types not supported yet!");
64 return Ctx.getComplexType(Result);
66 case DeclSpec::TST_float:
67 if (DS.getTypeSpecComplex() == DeclSpec::TSC_unspecified)
69 assert(DS.getTypeSpecComplex() == DeclSpec::TSC_complex &&
70 "FIXME: imaginary types not supported yet!");
71 return Ctx.getComplexType(Ctx.FloatTy);
73 case DeclSpec::TST_double: {
74 bool isLong = DS.getTypeSpecWidth() == DeclSpec::TSW_long;
75 QualType T = isLong ? Ctx.LongDoubleTy : Ctx.DoubleTy;
76 if (DS.getTypeSpecComplex() == DeclSpec::TSC_unspecified)
78 assert(DS.getTypeSpecComplex() == DeclSpec::TSC_complex &&
79 "FIXME: imaginary types not supported yet!");
80 return Ctx.getComplexType(T);
82 case DeclSpec::TST_bool: // _Bool or bool
84 case DeclSpec::TST_decimal32: // _Decimal32
85 case DeclSpec::TST_decimal64: // _Decimal64
86 case DeclSpec::TST_decimal128: // _Decimal128
87 assert(0 && "FIXME: GNU decimal extensions not supported yet!");
88 case DeclSpec::TST_enum:
89 case DeclSpec::TST_union:
90 case DeclSpec::TST_struct: {
91 Decl *D = static_cast<Decl *>(DS.getTypeRep());
92 assert(D && "Didn't get a decl for a enum/union/struct?");
93 assert(DS.getTypeSpecWidth() == 0 && DS.getTypeSpecComplex() == 0 &&
94 DS.getTypeSpecSign() == 0 &&
95 "Can't handle qualifiers on typedef names yet!");
96 // TypeQuals handled by caller.
97 return Ctx.getTagDeclType(cast<TagDecl>(D));
99 case DeclSpec::TST_typedef: {
100 Decl *D = static_cast<Decl *>(DS.getTypeRep());
101 assert(D && "Didn't get a decl for a typedef?");
102 assert(DS.getTypeSpecWidth() == 0 && DS.getTypeSpecComplex() == 0 &&
103 DS.getTypeSpecSign() == 0 &&
104 "Can't handle qualifiers on typedef names yet!");
105 // FIXME: Adding a TST_objcInterface clause doesn't seem ideal, so
106 // we have this "hack" for now...
107 if (ObjCInterfaceDecl *ObjCIntDecl = dyn_cast<ObjCInterfaceDecl>(D)) {
108 if (DS.getProtocolQualifiers() == 0)
109 return Ctx.getObjCInterfaceType(ObjCIntDecl);
111 Action::DeclTy **PPDecl = &(*DS.getProtocolQualifiers())[0];
112 return Ctx.getObjCQualifiedInterfaceType(ObjCIntDecl,
113 reinterpret_cast<ObjCProtocolDecl**>(PPDecl),
114 DS.NumProtocolQualifiers());
116 else if (TypedefDecl *typeDecl = dyn_cast<TypedefDecl>(D)) {
117 if (Ctx.getObjCIdType() == Ctx.getTypedefType(typeDecl)
118 && DS.getProtocolQualifiers()) {
120 Action::DeclTy **PPDecl = &(*DS.getProtocolQualifiers())[0];
121 return Ctx.getObjCQualifiedIdType(typeDecl->getUnderlyingType(),
122 reinterpret_cast<ObjCProtocolDecl**>(PPDecl),
123 DS.NumProtocolQualifiers());
126 // TypeQuals handled by caller.
127 return Ctx.getTypedefType(cast<TypedefDecl>(D));
129 case DeclSpec::TST_typeofType: {
130 QualType T = QualType::getFromOpaquePtr(DS.getTypeRep());
131 assert(!T.isNull() && "Didn't get a type for typeof?");
132 // TypeQuals handled by caller.
133 return Ctx.getTypeOfType(T);
135 case DeclSpec::TST_typeofExpr: {
136 Expr *E = static_cast<Expr *>(DS.getTypeRep());
137 assert(E && "Didn't get an expression for typeof?");
138 // TypeQuals handled by caller.
139 return Ctx.getTypeOfExpr(E);
144 /// GetTypeForDeclarator - Convert the type for the specified declarator to Type
146 QualType Sema::GetTypeForDeclarator(Declarator &D, Scope *S) {
147 // long long is a C99 feature.
148 if (!getLangOptions().C99 && !getLangOptions().CPlusPlus0x &&
149 D.getDeclSpec().getTypeSpecWidth() == DeclSpec::TSW_longlong)
150 Diag(D.getDeclSpec().getTypeSpecWidthLoc(), diag::ext_longlong);
152 QualType T = ConvertDeclSpecToType(D.getDeclSpec(), Context);
154 // Apply const/volatile/restrict qualifiers to T.
155 T = T.getQualifiedType(D.getDeclSpec().getTypeQualifiers());
157 // Walk the DeclTypeInfo, building the recursive type as we go. DeclTypeInfos
158 // are ordered from the identifier out, which is opposite of what we want :).
159 for (unsigned i = 0, e = D.getNumTypeObjects(); i != e; ++i) {
160 const DeclaratorChunk &DeclType = D.getTypeObject(e-i-1);
161 switch (DeclType.Kind) {
162 default: assert(0 && "Unknown decltype!");
163 case DeclaratorChunk::Pointer:
164 if (T->isReferenceType()) {
165 // C++ 8.3.2p4: There shall be no ... pointers to references ...
166 Diag(D.getIdentifierLoc(), diag::err_illegal_decl_pointer_to_reference,
167 D.getIdentifier() ? D.getIdentifier()->getName() : "type name");
168 D.setInvalidType(true);
172 // Apply the pointer typequals to the pointer object.
173 T = Context.getPointerType(T).getQualifiedType(DeclType.Ptr.TypeQuals);
175 case DeclaratorChunk::Reference:
176 if (const ReferenceType *RT = T->getAsReferenceType()) {
177 // C++ 8.3.2p4: There shall be no references to references ...
178 Diag(D.getIdentifierLoc(),
179 diag::err_illegal_decl_reference_to_reference,
180 D.getIdentifier() ? D.getIdentifier()->getName() : "type name");
181 D.setInvalidType(true);
182 T = RT->getReferenceeType();
185 T = Context.getReferenceType(T);
187 case DeclaratorChunk::Array: {
188 const DeclaratorChunk::ArrayTypeInfo &ATI = DeclType.Arr;
189 Expr *ArraySize = static_cast<Expr*>(ATI.NumElts);
190 ArrayType::ArraySizeModifier ASM;
192 ASM = ArrayType::Star;
193 else if (ATI.hasStatic)
194 ASM = ArrayType::Static;
196 ASM = ArrayType::Normal;
198 // C99 6.7.5.2p1: If the element type is an incomplete or function type,
199 // reject it (e.g. void ary[7], struct foo ary[7], void ary[7]())
200 if (T->isIncompleteType()) {
201 Diag(D.getIdentifierLoc(), diag::err_illegal_decl_array_incomplete_type,
204 D.setInvalidType(true);
205 } else if (T->isFunctionType()) {
206 Diag(D.getIdentifierLoc(), diag::err_illegal_decl_array_of_functions,
207 D.getIdentifier() ? D.getIdentifier()->getName() : "type name");
208 T = Context.getPointerType(T);
209 D.setInvalidType(true);
210 } else if (const ReferenceType *RT = T->getAsReferenceType()) {
211 // C++ 8.3.2p4: There shall be no ... arrays of references ...
212 Diag(D.getIdentifierLoc(), diag::err_illegal_decl_array_of_references,
213 D.getIdentifier() ? D.getIdentifier()->getName() : "type name");
214 T = RT->getReferenceeType();
215 D.setInvalidType(true);
216 } else if (const RecordType *EltTy = T->getAsRecordType()) {
217 // If the element type is a struct or union that contains a variadic
218 // array, reject it: C99 6.7.2.1p2.
219 if (EltTy->getDecl()->hasFlexibleArrayMember()) {
220 Diag(DeclType.Loc, diag::err_flexible_array_in_array,
223 D.setInvalidType(true);
226 // C99 6.7.5.2p1: The size expression shall have integer type.
227 if (ArraySize && !ArraySize->getType()->isIntegerType()) {
228 Diag(ArraySize->getLocStart(), diag::err_array_size_non_int,
229 ArraySize->getType().getAsString(), ArraySize->getSourceRange());
230 D.setInvalidType(true);
232 llvm::APSInt ConstVal(32);
233 // If no expression was provided, we consider it a VLA.
235 T = Context.getIncompleteArrayType(T, ASM, ATI.TypeQuals);
236 } else if (!ArraySize->isIntegerConstantExpr(ConstVal, Context)) {
237 T = Context.getVariableArrayType(T, ArraySize, ASM, ATI.TypeQuals);
239 // C99 6.7.5.2p1: If the expression is a constant expression, it shall
240 // have a value greater than zero.
241 if (ConstVal.isSigned()) {
242 if (ConstVal.isNegative()) {
243 Diag(ArraySize->getLocStart(),
244 diag::err_typecheck_negative_array_size,
245 ArraySize->getSourceRange());
246 D.setInvalidType(true);
247 } else if (ConstVal == 0) {
248 // GCC accepts zero sized static arrays.
249 Diag(ArraySize->getLocStart(), diag::ext_typecheck_zero_array_size,
250 ArraySize->getSourceRange());
253 T = Context.getConstantArrayType(T, ConstVal, ASM, ATI.TypeQuals);
255 // If this is not C99, extwarn about VLA's and C99 array size modifiers.
256 if (!getLangOptions().C99 &&
257 (ASM != ArrayType::Normal ||
258 (ArraySize && !ArraySize->isIntegerConstantExpr(Context))))
259 Diag(D.getIdentifierLoc(), diag::ext_vla);
262 case DeclaratorChunk::Function:
263 // If the function declarator has a prototype (i.e. it is not () and
264 // does not have a K&R-style identifier list), then the arguments are part
265 // of the type, otherwise the argument list is ().
266 const DeclaratorChunk::FunctionTypeInfo &FTI = DeclType.Fun;
268 // C99 6.7.5.3p1: The return type may not be a function or array type.
269 if (T->isArrayType() || T->isFunctionType()) {
270 Diag(DeclType.Loc, diag::err_func_returning_array_function,
273 D.setInvalidType(true);
276 if (!FTI.hasPrototype) {
277 // Simple void foo(), where the incoming T is the result type.
278 T = Context.getFunctionTypeNoProto(T);
280 // C99 6.7.5.3p3: Reject int(x,y,z) when it's not a function definition.
281 if (FTI.NumArgs != 0)
282 Diag(FTI.ArgInfo[0].IdentLoc, diag::err_ident_list_in_fn_declaration);
285 // Otherwise, we have a function with an argument list that is
286 // potentially variadic.
287 llvm::SmallVector<QualType, 16> ArgTys;
289 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) {
290 QualType ArgTy = QualType::getFromOpaquePtr(FTI.ArgInfo[i].TypeInfo);
291 assert(!ArgTy.isNull() && "Couldn't parse type?");
293 // Perform the default function/array conversion (C99 6.7.5.3p[7,8]).
294 // This matches the conversion that is done in
295 // Sema::ActOnParamDeclarator(). Without this conversion, the
296 // argument type in the function prototype *will not* match the
297 // type in ParmVarDecl (which makes the code generator unhappy).
299 // FIXME: We still apparently need the conversion in
300 // Sema::ParseParamDeclarator(). This doesn't make any sense, since
301 // it should be driving off the type being created here.
303 // FIXME: If a source translation tool needs to see the original type,
304 // then we need to consider storing both types somewhere...
306 if (const ArrayType *AT = ArgTy->getAsArrayType()) {
307 // int x[restrict 4] -> int *restrict
308 ArgTy = Context.getPointerType(AT->getElementType());
309 ArgTy = ArgTy.getQualifiedType(AT->getIndexTypeQualifier());
310 } else if (ArgTy->isFunctionType())
311 ArgTy = Context.getPointerType(ArgTy);
312 // Look for 'void'. void is allowed only as a single argument to a
313 // function with no other parameters (C99 6.7.5.3p10). We record
314 // int(void) as a FunctionTypeProto with an empty argument list.
315 else if (ArgTy->isVoidType()) {
316 // If this is something like 'float(int, void)', reject it. 'void'
317 // is an incomplete type (C99 6.2.5p19) and function decls cannot
318 // have arguments of incomplete type.
319 if (FTI.NumArgs != 1 || FTI.isVariadic) {
320 Diag(DeclType.Loc, diag::err_void_only_param);
321 ArgTy = Context.IntTy;
322 FTI.ArgInfo[i].TypeInfo = ArgTy.getAsOpaquePtr();
323 } else if (FTI.ArgInfo[i].Ident) {
324 // Reject, but continue to parse 'int(void abc)'.
325 Diag(FTI.ArgInfo[i].IdentLoc,
326 diag::err_param_with_void_type);
327 ArgTy = Context.IntTy;
328 FTI.ArgInfo[i].TypeInfo = ArgTy.getAsOpaquePtr();
330 // Reject, but continue to parse 'float(const void)'.
331 if (ArgTy.getCVRQualifiers())
332 Diag(DeclType.Loc, diag::err_void_param_qualified);
334 // Do not add 'void' to the ArgTys list.
339 ArgTys.push_back(ArgTy);
341 T = Context.getFunctionType(T, &ArgTys[0], ArgTys.size(),
351 /// ObjCGetTypeForMethodDefinition - Builds the type for a method definition
353 QualType Sema::ObjCGetTypeForMethodDefinition(DeclTy *D) {
354 ObjCMethodDecl *MDecl = dyn_cast<ObjCMethodDecl>(static_cast<Decl *>(D));
355 QualType T = MDecl->getResultType();
356 llvm::SmallVector<QualType, 16> ArgTys;
358 // Add the first two invisible argument types for self and _cmd.
359 if (MDecl->isInstance()) {
360 QualType selfTy = Context.getObjCInterfaceType(MDecl->getClassInterface());
361 selfTy = Context.getPointerType(selfTy);
362 ArgTys.push_back(selfTy);
365 ArgTys.push_back(Context.getObjCIdType());
366 ArgTys.push_back(Context.getObjCSelType());
368 for (int i = 0; i < MDecl->getNumParams(); i++) {
369 ParmVarDecl *PDecl = MDecl->getParamDecl(i);
370 QualType ArgTy = PDecl->getType();
371 assert(!ArgTy.isNull() && "Couldn't parse type?");
372 // Perform the default function/array conversion (C99 6.7.5.3p[7,8]).
373 // This matches the conversion that is done in
374 // Sema::ParseParamDeclarator().
375 if (const ArrayType *AT = ArgTy->getAsArrayType())
376 ArgTy = Context.getPointerType(AT->getElementType());
377 else if (ArgTy->isFunctionType())
378 ArgTy = Context.getPointerType(ArgTy);
379 ArgTys.push_back(ArgTy);
381 T = Context.getFunctionType(T, &ArgTys[0], ArgTys.size(),
382 MDecl->isVariadic());
386 Sema::TypeResult Sema::ActOnTypeName(Scope *S, Declarator &D) {
387 // C99 6.7.6: Type names have no identifier. This is already validated by
389 assert(D.getIdentifier() == 0 && "Type name should have no identifier!");
391 QualType T = GetTypeForDeclarator(D, S);
393 assert(!T.isNull() && "GetTypeForDeclarator() returned null type");
395 // In this context, we *do not* check D.getInvalidType(). If the declarator
396 // type was invalid, GetTypeForDeclarator() still returns a "valid" type,
397 // though it will not reflect the user specified type.
398 return T.getAsOpaquePtr();
401 // Called from Parser::ParseParenDeclarator().
402 Sema::TypeResult Sema::ActOnParamDeclaratorType(Scope *S, Declarator &D) {
403 // Note: parameters have identifiers, but we don't care about them here, we
404 // just want the type converted.
405 QualType T = GetTypeForDeclarator(D, S);
407 assert(!T.isNull() && "GetTypeForDeclarator() returned null type");
409 // In this context, we *do not* check D.getInvalidType(). If the declarator
410 // type was invalid, GetTypeForDeclarator() still returns a "valid" type,
411 // though it will not reflect the user specified type.
412 return T.getAsOpaquePtr();