Sema.cpp revision caaacecb2b64e6d2e402533baffda4cb540f4145
1//===--- Sema.cpp - AST Builder and Semantic Analysis Implementation ------===// 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 actions class which performs semantic analysis and 11// builds an AST out of a parse stream. 12// 13//===----------------------------------------------------------------------===// 14 15#include "Sema.h" 16#include "clang/AST/ASTContext.h" 17#include "clang/AST/DeclObjC.h" 18#include "clang/AST/Expr.h" 19#include "clang/Lex/Preprocessor.h" 20using namespace clang; 21 22/// ConvertQualTypeToStringFn - This function is used to pretty print the 23/// specified QualType as a string in diagnostics. 24static void ConvertArgToStringFn(Diagnostic::ArgumentKind Kind, intptr_t Val, 25 const char *Modifier, unsigned ModLen, 26 const char *Argument, unsigned ArgLen, 27 llvm::SmallVectorImpl<char> &Output, 28 void *Cookie) { 29 ASTContext &Context = *static_cast<ASTContext*>(Cookie); 30 31 std::string S; 32 if (Kind == Diagnostic::ak_qualtype) { 33 assert(ModLen == 0 && ArgLen == 0 && 34 "Invalid modifier for QualType argument"); 35 36 QualType Ty(QualType::getFromOpaquePtr(reinterpret_cast<void*>(Val))); 37 38 // FIXME: Playing with std::string is really slow. 39 S = Ty.getAsString(); 40 41 // If this is a sugared type (like a typedef, typeof, etc), then unwrap one 42 // level of the sugar so that the type is more obvious to the user. 43 QualType DesugaredTy = Ty->getDesugaredType(); 44 DesugaredTy.setCVRQualifiers(DesugaredTy.getCVRQualifiers() | 45 Ty.getCVRQualifiers()); 46 47 if (Ty != DesugaredTy && 48 // If the desugared type is a vector type, we don't want to expand it, 49 // it will turn into an attribute mess. People want their "vec4". 50 !isa<VectorType>(DesugaredTy) && 51 52 // Don't desugar magic Objective-C types. 53 Ty.getUnqualifiedType() != Context.getObjCIdType() && 54 Ty.getUnqualifiedType() != Context.getObjCSelType() && 55 Ty.getUnqualifiedType() != Context.getObjCProtoType() && 56 Ty.getUnqualifiedType() != Context.getObjCClassType() && 57 58 // Not va_list. 59 Ty.getUnqualifiedType() != Context.getBuiltinVaListType()) { 60 S = "'"+S+"' (aka '"; 61 S += DesugaredTy.getAsString(); 62 S += "')"; 63 Output.append(S.begin(), S.end()); 64 return; 65 } 66 67 } else if (Kind == Diagnostic::ak_declarationname) { 68 69 DeclarationName N = DeclarationName::getFromOpaqueInteger(Val); 70 S = N.getAsString(); 71 72 if (ModLen == 9 && !memcmp(Modifier, "objcclass", 9) && ArgLen == 0) 73 S = '+' + S; 74 else if (ModLen == 12 && !memcmp(Modifier, "objcinstance", 12) && ArgLen==0) 75 S = '-' + S; 76 else 77 assert(ModLen == 0 && ArgLen == 0 && 78 "Invalid modifier for DeclarationName argument"); 79 } else { 80 assert(Kind == Diagnostic::ak_nameddecl); 81 if (ModLen == 1 && Modifier[0] == 'q' && ArgLen == 0) 82 S = reinterpret_cast<NamedDecl*>(Val)->getQualifiedNameAsString(); 83 else { 84 assert(ModLen == 0 && ArgLen == 0 && 85 "Invalid modifier for NamedDecl* argument"); 86 S = reinterpret_cast<NamedDecl*>(Val)->getNameAsString(); 87 } 88 } 89 90 Output.push_back('\''); 91 Output.append(S.begin(), S.end()); 92 Output.push_back('\''); 93} 94 95 96static inline RecordDecl *CreateStructDecl(ASTContext &C, const char *Name) { 97 if (C.getLangOptions().CPlusPlus) 98 return CXXRecordDecl::Create(C, TagDecl::TK_struct, 99 C.getTranslationUnitDecl(), 100 SourceLocation(), &C.Idents.get(Name)); 101 102 return RecordDecl::Create(C, TagDecl::TK_struct, 103 C.getTranslationUnitDecl(), 104 SourceLocation(), &C.Idents.get(Name)); 105} 106 107void Sema::ActOnTranslationUnitScope(SourceLocation Loc, Scope *S) { 108 TUScope = S; 109 PushDeclContext(S, Context.getTranslationUnitDecl()); 110 if (!PP.getLangOptions().ObjC1) return; 111 112 // Synthesize "typedef struct objc_selector *SEL;" 113 RecordDecl *SelTag = CreateStructDecl(Context, "objc_selector"); 114 PushOnScopeChains(SelTag, TUScope); 115 116 QualType SelT = Context.getPointerType(Context.getTagDeclType(SelTag)); 117 TypedefDecl *SelTypedef = TypedefDecl::Create(Context, CurContext, 118 SourceLocation(), 119 &Context.Idents.get("SEL"), 120 SelT); 121 PushOnScopeChains(SelTypedef, TUScope); 122 Context.setObjCSelType(SelTypedef); 123 124 // FIXME: Make sure these don't leak! 125 RecordDecl *ClassTag = CreateStructDecl(Context, "objc_class"); 126 QualType ClassT = Context.getPointerType(Context.getTagDeclType(ClassTag)); 127 TypedefDecl *ClassTypedef = 128 TypedefDecl::Create(Context, CurContext, SourceLocation(), 129 &Context.Idents.get("Class"), ClassT); 130 PushOnScopeChains(ClassTag, TUScope); 131 PushOnScopeChains(ClassTypedef, TUScope); 132 Context.setObjCClassType(ClassTypedef); 133 // Synthesize "@class Protocol; 134 ObjCInterfaceDecl *ProtocolDecl = 135 ObjCInterfaceDecl::Create(Context, CurContext, SourceLocation(), 136 &Context.Idents.get("Protocol"), 137 SourceLocation(), true); 138 Context.setObjCProtoType(Context.getObjCInterfaceType(ProtocolDecl)); 139 PushOnScopeChains(ProtocolDecl, TUScope); 140 141 // Synthesize "typedef struct objc_object { Class isa; } *id;" 142 RecordDecl *ObjectTag = CreateStructDecl(Context, "objc_object"); 143 144 QualType ObjT = Context.getPointerType(Context.getTagDeclType(ObjectTag)); 145 PushOnScopeChains(ObjectTag, TUScope); 146 TypedefDecl *IdTypedef = TypedefDecl::Create(Context, CurContext, 147 SourceLocation(), 148 &Context.Idents.get("id"), 149 ObjT); 150 PushOnScopeChains(IdTypedef, TUScope); 151 Context.setObjCIdType(IdTypedef); 152} 153 154Sema::Sema(Preprocessor &pp, ASTContext &ctxt, ASTConsumer &consumer) 155 : LangOpts(pp.getLangOptions()), PP(pp), Context(ctxt), Consumer(consumer), 156 Diags(PP.getDiagnostics()), 157 SourceMgr(PP.getSourceManager()), CurContext(0), PreDeclaratorDC(0), 158 CurBlock(0), PackContext(0), IdResolver(pp.getLangOptions()), 159 GlobalNewDeleteDeclared(false) { 160 161 // Get IdentifierInfo objects for known functions for which we 162 // do extra checking. 163 IdentifierTable &IT = PP.getIdentifierTable(); 164 165 KnownFunctionIDs[id_NSLog] = &IT.get("NSLog"); 166 KnownFunctionIDs[id_NSLogv] = &IT.get("NSLogv"); 167 KnownFunctionIDs[id_asprintf] = &IT.get("asprintf"); 168 KnownFunctionIDs[id_vasprintf] = &IT.get("vasprintf"); 169 170 StdNamespace = 0; 171 TUScope = 0; 172 if (getLangOptions().CPlusPlus) 173 FieldCollector.reset(new CXXFieldCollector()); 174 175 // Tell diagnostics how to render things from the AST library. 176 PP.getDiagnostics().SetArgToStringFn(ConvertArgToStringFn, &Context); 177} 178 179/// ImpCastExprToType - If Expr is not of type 'Type', insert an implicit cast. 180/// If there is already an implicit cast, merge into the existing one. 181/// If isLvalue, the result of the cast is an lvalue. 182void Sema::ImpCastExprToType(Expr *&Expr, QualType Ty, bool isLvalue) { 183 QualType ExprTy = Context.getCanonicalType(Expr->getType()); 184 QualType TypeTy = Context.getCanonicalType(Ty); 185 186 if (ExprTy == TypeTy) 187 return; 188 189 if (Expr->getType().getTypePtr()->isPointerType() && 190 Ty.getTypePtr()->isPointerType()) { 191 QualType ExprBaseType = 192 cast<PointerType>(ExprTy.getUnqualifiedType())->getPointeeType(); 193 QualType BaseType = 194 cast<PointerType>(TypeTy.getUnqualifiedType())->getPointeeType(); 195 if (ExprBaseType.getAddressSpace() != BaseType.getAddressSpace()) { 196 Diag(Expr->getExprLoc(), diag::err_implicit_pointer_address_space_cast) 197 << Expr->getSourceRange(); 198 } 199 } 200 201 if (ImplicitCastExpr *ImpCast = dyn_cast<ImplicitCastExpr>(Expr)) { 202 ImpCast->setType(Ty); 203 ImpCast->setLvalueCast(isLvalue); 204 } else 205 Expr = new (Context) ImplicitCastExpr(Ty, Expr, isLvalue); 206} 207 208void Sema::DeleteExpr(ExprTy *E) { 209 if (E) static_cast<Expr*>(E)->Destroy(Context); 210} 211void Sema::DeleteStmt(StmtTy *S) { 212 if (S) static_cast<Stmt*>(S)->Destroy(Context); 213} 214 215/// ActOnEndOfTranslationUnit - This is called at the very end of the 216/// translation unit when EOF is reached and all but the top-level scope is 217/// popped. 218void Sema::ActOnEndOfTranslationUnit() { 219 // C99 6.9.2p2: 220 // A declaration of an identifier for an object that has file 221 // scope without an initializer, and without a storage-class 222 // specifier or with the storage-class specifier static, 223 // constitutes a tentative definition. If a translation unit 224 // contains one or more tentative definitions for an identifier, 225 // and the translation unit contains no external definition for 226 // that identifier, then the behavior is exactly as if the 227 // translation unit contains a file scope declaration of that 228 // identifier, with the composite type as of the end of the 229 // translation unit, with an initializer equal to 0. 230 if (!getLangOptions().CPlusPlus) { 231 // Note: we traverse the scope's list of declarations rather than 232 // the DeclContext's list, because we only want to see the most 233 // recent declaration of each identifier. 234 for (Scope::decl_iterator I = TUScope->decl_begin(), 235 IEnd = TUScope->decl_end(); 236 I != IEnd; ++I) { 237 Decl *D = static_cast<Decl *>(*I); 238 if (D->isInvalidDecl()) 239 continue; 240 241 if (VarDecl *VD = dyn_cast<VarDecl>(D)) { 242 if (VD->isTentativeDefinition(Context)) { 243 if (const IncompleteArrayType *ArrayT 244 = Context.getAsIncompleteArrayType(VD->getType())) { 245 if (RequireCompleteType(VD->getLocation(), 246 ArrayT->getElementType(), 247 diag::err_tentative_def_incomplete_type_arr)) 248 VD->setInvalidDecl(); 249 else { 250 // Set the length of the array to 1 (C99 6.9.2p5). 251 llvm::APSInt One(Context.getTypeSize(Context.getSizeType()), 252 true); 253 QualType T 254 = Context.getConstantArrayType(ArrayT->getElementType(), 255 One, ArrayType::Normal, 0); 256 VD->setType(T); 257 } 258 } else if (RequireCompleteType(VD->getLocation(), VD->getType(), 259 diag::err_tentative_def_incomplete_type)) 260 VD->setInvalidDecl(); 261 } 262 } 263 } 264 } 265} 266 267 268//===----------------------------------------------------------------------===// 269// Helper functions. 270//===----------------------------------------------------------------------===// 271 272/// getCurFunctionDecl - If inside of a function body, this returns a pointer 273/// to the function decl for the function being parsed. If we're currently 274/// in a 'block', this returns the containing context. 275FunctionDecl *Sema::getCurFunctionDecl() { 276 DeclContext *DC = CurContext; 277 while (isa<BlockDecl>(DC)) 278 DC = DC->getParent(); 279 return dyn_cast<FunctionDecl>(DC); 280} 281 282ObjCMethodDecl *Sema::getCurMethodDecl() { 283 DeclContext *DC = CurContext; 284 while (isa<BlockDecl>(DC)) 285 DC = DC->getParent(); 286 return dyn_cast<ObjCMethodDecl>(DC); 287} 288 289NamedDecl *Sema::getCurFunctionOrMethodDecl() { 290 DeclContext *DC = CurContext; 291 while (isa<BlockDecl>(DC)) 292 DC = DC->getParent(); 293 if (isa<ObjCMethodDecl>(DC) || isa<FunctionDecl>(DC)) 294 return cast<NamedDecl>(DC); 295 return 0; 296} 297 298