Sema.cpp revision 48dd19b19ddb9e105f8cf0bf6f0732ca4e6a385b
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/ASTConsumer.h" 17#include "clang/AST/ASTContext.h" 18#include "clang/AST/DeclObjC.h" 19#include "clang/AST/Expr.h" 20#include "clang/Lex/Preprocessor.h" 21#include "clang/Basic/TargetInfo.h" 22using namespace clang; 23 24/// ConvertQualTypeToStringFn - This function is used to pretty print the 25/// specified QualType as a string in diagnostics. 26static void ConvertArgToStringFn(Diagnostic::ArgumentKind Kind, intptr_t Val, 27 const char *Modifier, unsigned ModLen, 28 const char *Argument, unsigned ArgLen, 29 llvm::SmallVectorImpl<char> &Output, 30 void *Cookie) { 31 ASTContext &Context = *static_cast<ASTContext*>(Cookie); 32 33 std::string S; 34 if (Kind == Diagnostic::ak_qualtype) { 35 assert(ModLen == 0 && ArgLen == 0 && 36 "Invalid modifier for QualType argument"); 37 38 QualType Ty(QualType::getFromOpaquePtr(reinterpret_cast<void*>(Val))); 39 40 // FIXME: Playing with std::string is really slow. 41 S = Ty.getAsString(); 42 43 // If this is a sugared type (like a typedef, typeof, etc), then unwrap one 44 // level of the sugar so that the type is more obvious to the user. 45 QualType DesugaredTy = Ty->getDesugaredType(true); 46 DesugaredTy.setCVRQualifiers(DesugaredTy.getCVRQualifiers() | 47 Ty.getCVRQualifiers()); 48 49 if (Ty != DesugaredTy && 50 // If the desugared type is a vector type, we don't want to expand it, 51 // it will turn into an attribute mess. People want their "vec4". 52 !isa<VectorType>(DesugaredTy) && 53 54 // Don't desugar magic Objective-C types. 55 Ty.getUnqualifiedType() != Context.getObjCIdType() && 56 Ty.getUnqualifiedType() != Context.getObjCSelType() && 57 Ty.getUnqualifiedType() != Context.getObjCProtoType() && 58 Ty.getUnqualifiedType() != Context.getObjCClassType() && 59 60 // Not va_list. 61 Ty.getUnqualifiedType() != Context.getBuiltinVaListType()) { 62 S = "'"+S+"' (aka '"; 63 S += DesugaredTy.getAsString(); 64 S += "')"; 65 Output.append(S.begin(), S.end()); 66 return; 67 } 68 69 } else if (Kind == Diagnostic::ak_declarationname) { 70 71 DeclarationName N = DeclarationName::getFromOpaqueInteger(Val); 72 S = N.getAsString(); 73 74 if (ModLen == 9 && !memcmp(Modifier, "objcclass", 9) && ArgLen == 0) 75 S = '+' + S; 76 else if (ModLen == 12 && !memcmp(Modifier, "objcinstance", 12) && ArgLen==0) 77 S = '-' + S; 78 else 79 assert(ModLen == 0 && ArgLen == 0 && 80 "Invalid modifier for DeclarationName argument"); 81 } else { 82 assert(Kind == Diagnostic::ak_nameddecl); 83 if (ModLen == 1 && Modifier[0] == 'q' && ArgLen == 0) 84 S = reinterpret_cast<NamedDecl*>(Val)->getQualifiedNameAsString(); 85 else { 86 assert(ModLen == 0 && ArgLen == 0 && 87 "Invalid modifier for NamedDecl* argument"); 88 S = reinterpret_cast<NamedDecl*>(Val)->getNameAsString(); 89 } 90 } 91 92 Output.push_back('\''); 93 Output.append(S.begin(), S.end()); 94 Output.push_back('\''); 95} 96 97 98static inline RecordDecl *CreateStructDecl(ASTContext &C, const char *Name) { 99 if (C.getLangOptions().CPlusPlus) 100 return CXXRecordDecl::Create(C, TagDecl::TK_struct, 101 C.getTranslationUnitDecl(), 102 SourceLocation(), &C.Idents.get(Name)); 103 104 return RecordDecl::Create(C, TagDecl::TK_struct, 105 C.getTranslationUnitDecl(), 106 SourceLocation(), &C.Idents.get(Name)); 107} 108 109void Sema::ActOnTranslationUnitScope(SourceLocation Loc, Scope *S) { 110 TUScope = S; 111 PushDeclContext(S, Context.getTranslationUnitDecl()); 112 113 if (PP.getTargetInfo().getPointerWidth(0) >= 64) { 114 // Install [u]int128_t for 64-bit targets. 115 PushOnScopeChains(TypedefDecl::Create(Context, CurContext, 116 SourceLocation(), 117 &Context.Idents.get("__int128_t"), 118 Context.Int128Ty), TUScope); 119 PushOnScopeChains(TypedefDecl::Create(Context, CurContext, 120 SourceLocation(), 121 &Context.Idents.get("__uint128_t"), 122 Context.UnsignedInt128Ty), TUScope); 123 } 124 125 126 if (!PP.getLangOptions().ObjC1) return; 127 128 if (Context.getObjCSelType().isNull()) { 129 // Synthesize "typedef struct objc_selector *SEL;" 130 RecordDecl *SelTag = CreateStructDecl(Context, "objc_selector"); 131 PushOnScopeChains(SelTag, TUScope); 132 133 QualType SelT = Context.getPointerType(Context.getTagDeclType(SelTag)); 134 TypedefDecl *SelTypedef = TypedefDecl::Create(Context, CurContext, 135 SourceLocation(), 136 &Context.Idents.get("SEL"), 137 SelT); 138 PushOnScopeChains(SelTypedef, TUScope); 139 Context.setObjCSelType(Context.getTypeDeclType(SelTypedef)); 140 } 141 142 if (Context.getObjCClassType().isNull()) { 143 RecordDecl *ClassTag = CreateStructDecl(Context, "objc_class"); 144 QualType ClassT = Context.getPointerType(Context.getTagDeclType(ClassTag)); 145 TypedefDecl *ClassTypedef = 146 TypedefDecl::Create(Context, CurContext, SourceLocation(), 147 &Context.Idents.get("Class"), ClassT); 148 PushOnScopeChains(ClassTag, TUScope); 149 PushOnScopeChains(ClassTypedef, TUScope); 150 Context.setObjCClassType(Context.getTypeDeclType(ClassTypedef)); 151 } 152 153 // Synthesize "@class Protocol; 154 if (Context.getObjCProtoType().isNull()) { 155 ObjCInterfaceDecl *ProtocolDecl = 156 ObjCInterfaceDecl::Create(Context, CurContext, SourceLocation(), 157 &Context.Idents.get("Protocol"), 158 SourceLocation(), true); 159 Context.setObjCProtoType(Context.getObjCInterfaceType(ProtocolDecl)); 160 PushOnScopeChains(ProtocolDecl, TUScope); 161 } 162 163 // Synthesize "typedef struct objc_object { Class isa; } *id;" 164 if (Context.getObjCIdType().isNull()) { 165 RecordDecl *ObjectTag = CreateStructDecl(Context, "objc_object"); 166 167 QualType ObjT = Context.getPointerType(Context.getTagDeclType(ObjectTag)); 168 PushOnScopeChains(ObjectTag, TUScope); 169 TypedefDecl *IdTypedef = TypedefDecl::Create(Context, CurContext, 170 SourceLocation(), 171 &Context.Idents.get("id"), 172 ObjT); 173 PushOnScopeChains(IdTypedef, TUScope); 174 Context.setObjCIdType(Context.getTypeDeclType(IdTypedef)); 175 } 176} 177 178Sema::Sema(Preprocessor &pp, ASTContext &ctxt, ASTConsumer &consumer, 179 bool CompleteTranslationUnit) 180 : LangOpts(pp.getLangOptions()), PP(pp), Context(ctxt), Consumer(consumer), 181 Diags(PP.getDiagnostics()), SourceMgr(PP.getSourceManager()), 182 ExternalSource(0), CurContext(0), PreDeclaratorDC(0), 183 CurBlock(0), PackContext(0), IdResolver(pp.getLangOptions()), 184 GlobalNewDeleteDeclared(false), 185 CompleteTranslationUnit(CompleteTranslationUnit), 186 CurrentInstantiationScope(0) { 187 188 StdNamespace = 0; 189 TUScope = 0; 190 if (getLangOptions().CPlusPlus) 191 FieldCollector.reset(new CXXFieldCollector()); 192 193 // Tell diagnostics how to render things from the AST library. 194 PP.getDiagnostics().SetArgToStringFn(ConvertArgToStringFn, &Context); 195} 196 197/// ImpCastExprToType - If Expr is not of type 'Type', insert an implicit cast. 198/// If there is already an implicit cast, merge into the existing one. 199/// If isLvalue, the result of the cast is an lvalue. 200void Sema::ImpCastExprToType(Expr *&Expr, QualType Ty, bool isLvalue) { 201 QualType ExprTy = Context.getCanonicalType(Expr->getType()); 202 QualType TypeTy = Context.getCanonicalType(Ty); 203 204 if (ExprTy == TypeTy) 205 return; 206 207 if (Expr->getType().getTypePtr()->isPointerType() && 208 Ty.getTypePtr()->isPointerType()) { 209 QualType ExprBaseType = 210 cast<PointerType>(ExprTy.getUnqualifiedType())->getPointeeType(); 211 QualType BaseType = 212 cast<PointerType>(TypeTy.getUnqualifiedType())->getPointeeType(); 213 if (ExprBaseType.getAddressSpace() != BaseType.getAddressSpace()) { 214 Diag(Expr->getExprLoc(), diag::err_implicit_pointer_address_space_cast) 215 << Expr->getSourceRange(); 216 } 217 } 218 219 if (ImplicitCastExpr *ImpCast = dyn_cast<ImplicitCastExpr>(Expr)) { 220 ImpCast->setType(Ty); 221 ImpCast->setLvalueCast(isLvalue); 222 } else 223 Expr = new (Context) ImplicitCastExpr(Ty, Expr, isLvalue); 224} 225 226void Sema::DeleteExpr(ExprTy *E) { 227 if (E) static_cast<Expr*>(E)->Destroy(Context); 228} 229void Sema::DeleteStmt(StmtTy *S) { 230 if (S) static_cast<Stmt*>(S)->Destroy(Context); 231} 232 233/// ActOnEndOfTranslationUnit - This is called at the very end of the 234/// translation unit when EOF is reached and all but the top-level scope is 235/// popped. 236void Sema::ActOnEndOfTranslationUnit() { 237 if (!CompleteTranslationUnit) 238 return; 239 240 // C99 6.9.2p2: 241 // A declaration of an identifier for an object that has file 242 // scope without an initializer, and without a storage-class 243 // specifier or with the storage-class specifier static, 244 // constitutes a tentative definition. If a translation unit 245 // contains one or more tentative definitions for an identifier, 246 // and the translation unit contains no external definition for 247 // that identifier, then the behavior is exactly as if the 248 // translation unit contains a file scope declaration of that 249 // identifier, with the composite type as of the end of the 250 // translation unit, with an initializer equal to 0. 251 for (llvm::DenseMap<DeclarationName, VarDecl *>::iterator 252 D = TentativeDefinitions.begin(), 253 DEnd = TentativeDefinitions.end(); 254 D != DEnd; ++D) { 255 VarDecl *VD = D->second; 256 257 if (VD->isInvalidDecl() || !VD->isTentativeDefinition(Context)) 258 continue; 259 260 if (const IncompleteArrayType *ArrayT 261 = Context.getAsIncompleteArrayType(VD->getType())) { 262 if (RequireCompleteType(VD->getLocation(), 263 ArrayT->getElementType(), 264 diag::err_tentative_def_incomplete_type_arr)) 265 VD->setInvalidDecl(); 266 else { 267 // Set the length of the array to 1 (C99 6.9.2p5). 268 Diag(VD->getLocation(), diag::warn_tentative_incomplete_array); 269 llvm::APInt One(Context.getTypeSize(Context.getSizeType()), 270 true); 271 QualType T 272 = Context.getConstantArrayType(ArrayT->getElementType(), 273 One, ArrayType::Normal, 0); 274 VD->setType(T); 275 } 276 } else if (RequireCompleteType(VD->getLocation(), VD->getType(), 277 diag::err_tentative_def_incomplete_type)) 278 VD->setInvalidDecl(); 279 280 // Notify the consumer that we've completed a tentative definition. 281 if (!VD->isInvalidDecl()) 282 Consumer.CompleteTentativeDefinition(VD); 283 284 } 285} 286 287 288//===----------------------------------------------------------------------===// 289// Helper functions. 290//===----------------------------------------------------------------------===// 291 292/// getCurFunctionDecl - If inside of a function body, this returns a pointer 293/// to the function decl for the function being parsed. If we're currently 294/// in a 'block', this returns the containing context. 295FunctionDecl *Sema::getCurFunctionDecl() { 296 DeclContext *DC = CurContext; 297 while (isa<BlockDecl>(DC)) 298 DC = DC->getParent(); 299 return dyn_cast<FunctionDecl>(DC); 300} 301 302ObjCMethodDecl *Sema::getCurMethodDecl() { 303 DeclContext *DC = CurContext; 304 while (isa<BlockDecl>(DC)) 305 DC = DC->getParent(); 306 return dyn_cast<ObjCMethodDecl>(DC); 307} 308 309NamedDecl *Sema::getCurFunctionOrMethodDecl() { 310 DeclContext *DC = CurContext; 311 while (isa<BlockDecl>(DC)) 312 DC = DC->getParent(); 313 if (isa<ObjCMethodDecl>(DC) || isa<FunctionDecl>(DC)) 314 return cast<NamedDecl>(DC); 315 return 0; 316} 317 318Sema::SemaDiagnosticBuilder::~SemaDiagnosticBuilder() { 319 this->Emit(); 320 321 // If this is not a note, and we're in a template instantiation 322 // that is different from the last template instantiation where 323 // we emitted an error, print a template instantiation 324 // backtrace. 325 if (!SemaRef.Diags.isBuiltinNote(DiagID) && 326 !SemaRef.ActiveTemplateInstantiations.empty() && 327 SemaRef.ActiveTemplateInstantiations.back() 328 != SemaRef.LastTemplateInstantiationErrorContext) { 329 SemaRef.PrintInstantiationStack(); 330 SemaRef.LastTemplateInstantiationErrorContext 331 = SemaRef.ActiveTemplateInstantiations.back(); 332 } 333} 334