Reid Spencer | 5f016e2 | 2007-07-11 17:01:13 +0000 | [diff] [blame] | 1 | //===--- SemaExprCXX.cpp - Semantic Analysis for Expressions --------------===// |
| 2 | // |
| 3 | // The LLVM Compiler Infrastructure |
| 4 | // |
Chris Lattner | 0bc735f | 2007-12-29 19:59:25 +0000 | [diff] [blame] | 5 | // This file is distributed under the University of Illinois Open Source |
| 6 | // License. See LICENSE.TXT for details. |
Reid Spencer | 5f016e2 | 2007-07-11 17:01:13 +0000 | [diff] [blame] | 7 | // |
| 8 | //===----------------------------------------------------------------------===// |
| 9 | // |
| 10 | // This file implements semantic analysis for C++ expressions. |
| 11 | // |
| 12 | //===----------------------------------------------------------------------===// |
| 13 | |
| 14 | #include "Sema.h" |
| 15 | #include "clang/AST/ExprCXX.h" |
Steve Naroff | 210679c | 2007-08-25 14:02:58 +0000 | [diff] [blame] | 16 | #include "clang/AST/ASTContext.h" |
Argyrios Kyrtzidis | 5921093 | 2008-09-10 02:17:11 +0000 | [diff] [blame] | 17 | #include "clang/Parse/DeclSpec.h" |
Argyrios Kyrtzidis | 4021a84 | 2008-10-06 23:16:35 +0000 | [diff] [blame] | 18 | #include "clang/Lex/Preprocessor.h" |
Daniel Dunbar | 12bc692 | 2008-08-11 03:27:53 +0000 | [diff] [blame] | 19 | #include "clang/Basic/Diagnostic.h" |
Reid Spencer | 5f016e2 | 2007-07-11 17:01:13 +0000 | [diff] [blame] | 20 | using namespace clang; |
| 21 | |
Steve Naroff | 1b273c4 | 2007-09-16 14:56:35 +0000 | [diff] [blame] | 22 | /// ActOnCXXCasts - Parse {dynamic,static,reinterpret,const}_cast's. |
Reid Spencer | 5f016e2 | 2007-07-11 17:01:13 +0000 | [diff] [blame] | 23 | Action::ExprResult |
Steve Naroff | 1b273c4 | 2007-09-16 14:56:35 +0000 | [diff] [blame] | 24 | Sema::ActOnCXXCasts(SourceLocation OpLoc, tok::TokenKind Kind, |
Reid Spencer | 5f016e2 | 2007-07-11 17:01:13 +0000 | [diff] [blame] | 25 | SourceLocation LAngleBracketLoc, TypeTy *Ty, |
| 26 | SourceLocation RAngleBracketLoc, |
| 27 | SourceLocation LParenLoc, ExprTy *E, |
| 28 | SourceLocation RParenLoc) { |
| 29 | CXXCastExpr::Opcode Op; |
| 30 | |
| 31 | switch (Kind) { |
| 32 | default: assert(0 && "Unknown C++ cast!"); |
| 33 | case tok::kw_const_cast: Op = CXXCastExpr::ConstCast; break; |
| 34 | case tok::kw_dynamic_cast: Op = CXXCastExpr::DynamicCast; break; |
| 35 | case tok::kw_reinterpret_cast: Op = CXXCastExpr::ReinterpretCast; break; |
| 36 | case tok::kw_static_cast: Op = CXXCastExpr::StaticCast; break; |
| 37 | } |
| 38 | |
| 39 | return new CXXCastExpr(Op, QualType::getFromOpaquePtr(Ty), (Expr*)E, OpLoc); |
| 40 | } |
| 41 | |
Steve Naroff | 1b273c4 | 2007-09-16 14:56:35 +0000 | [diff] [blame] | 42 | /// ActOnCXXBoolLiteral - Parse {true,false} literals. |
Reid Spencer | 5f016e2 | 2007-07-11 17:01:13 +0000 | [diff] [blame] | 43 | Action::ExprResult |
Steve Naroff | 1b273c4 | 2007-09-16 14:56:35 +0000 | [diff] [blame] | 44 | Sema::ActOnCXXBoolLiteral(SourceLocation OpLoc, tok::TokenKind Kind) { |
Reid Spencer | 5f016e2 | 2007-07-11 17:01:13 +0000 | [diff] [blame] | 45 | assert((Kind != tok::kw_true || Kind != tok::kw_false) && |
| 46 | "Unknown C++ Boolean value!"); |
Steve Naroff | 210679c | 2007-08-25 14:02:58 +0000 | [diff] [blame] | 47 | return new CXXBoolLiteralExpr(Kind == tok::kw_true, Context.BoolTy, OpLoc); |
Reid Spencer | 5f016e2 | 2007-07-11 17:01:13 +0000 | [diff] [blame] | 48 | } |
Chris Lattner | 50dd289 | 2008-02-26 00:51:44 +0000 | [diff] [blame] | 49 | |
| 50 | /// ActOnCXXThrow - Parse throw expressions. |
| 51 | Action::ExprResult |
| 52 | Sema::ActOnCXXThrow(SourceLocation OpLoc, ExprTy *E) { |
| 53 | return new CXXThrowExpr((Expr*)E, Context.VoidTy, OpLoc); |
| 54 | } |
Argyrios Kyrtzidis | 0795232 | 2008-07-01 10:37:29 +0000 | [diff] [blame] | 55 | |
| 56 | Action::ExprResult Sema::ActOnCXXThis(SourceLocation ThisLoc) { |
| 57 | /// C++ 9.3.2: In the body of a non-static member function, the keyword this |
| 58 | /// is a non-lvalue expression whose value is the address of the object for |
| 59 | /// which the function is called. |
| 60 | |
| 61 | if (!isa<FunctionDecl>(CurContext)) { |
| 62 | Diag(ThisLoc, diag::err_invalid_this_use); |
| 63 | return ExprResult(true); |
| 64 | } |
| 65 | |
| 66 | if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(CurContext)) |
| 67 | if (MD->isInstance()) |
Chris Lattner | d9f6910 | 2008-08-10 01:53:14 +0000 | [diff] [blame] | 68 | return new PredefinedExpr(ThisLoc, MD->getThisType(Context), |
| 69 | PredefinedExpr::CXXThis); |
Argyrios Kyrtzidis | 0795232 | 2008-07-01 10:37:29 +0000 | [diff] [blame] | 70 | |
| 71 | return Diag(ThisLoc, diag::err_invalid_this_use); |
| 72 | } |
Argyrios Kyrtzidis | 987a14b | 2008-08-22 15:38:55 +0000 | [diff] [blame] | 73 | |
| 74 | /// ActOnCXXTypeConstructExpr - Parse construction of a specified type. |
| 75 | /// Can be interpreted either as function-style casting ("int(x)") |
| 76 | /// or class type construction ("ClassType(x,y,z)") |
| 77 | /// or creation of a value-initialized type ("int()"). |
| 78 | Action::ExprResult |
| 79 | Sema::ActOnCXXTypeConstructExpr(SourceRange TypeRange, TypeTy *TypeRep, |
| 80 | SourceLocation LParenLoc, |
| 81 | ExprTy **ExprTys, unsigned NumExprs, |
| 82 | SourceLocation *CommaLocs, |
| 83 | SourceLocation RParenLoc) { |
| 84 | assert(TypeRep && "Missing type!"); |
| 85 | QualType Ty = QualType::getFromOpaquePtr(TypeRep); |
| 86 | Expr **Exprs = (Expr**)ExprTys; |
| 87 | SourceLocation TyBeginLoc = TypeRange.getBegin(); |
| 88 | SourceRange FullRange = SourceRange(TyBeginLoc, RParenLoc); |
| 89 | |
| 90 | if (const RecordType *RT = Ty->getAsRecordType()) { |
| 91 | // C++ 5.2.3p1: |
| 92 | // If the simple-type-specifier specifies a class type, the class type shall |
| 93 | // be complete. |
| 94 | // |
| 95 | if (!RT->getDecl()->isDefinition()) |
| 96 | return Diag(TyBeginLoc, diag::err_invalid_incomplete_type_use, |
| 97 | Ty.getAsString(), FullRange); |
| 98 | |
Argyrios Kyrtzidis | 4021a84 | 2008-10-06 23:16:35 +0000 | [diff] [blame] | 99 | unsigned DiagID = PP.getDiagnostics().getCustomDiagID(Diagnostic::Error, |
| 100 | "class constructors are not supported yet"); |
| 101 | return Diag(TyBeginLoc, DiagID); |
Argyrios Kyrtzidis | 987a14b | 2008-08-22 15:38:55 +0000 | [diff] [blame] | 102 | } |
| 103 | |
| 104 | // C++ 5.2.3p1: |
| 105 | // If the expression list is a single expression, the type conversion |
| 106 | // expression is equivalent (in definedness, and if defined in meaning) to the |
| 107 | // corresponding cast expression. |
| 108 | // |
| 109 | if (NumExprs == 1) { |
| 110 | if (CheckCastTypes(TypeRange, Ty, Exprs[0])) |
| 111 | return true; |
| 112 | return new CXXFunctionalCastExpr(Ty, TyBeginLoc, Exprs[0], RParenLoc); |
| 113 | } |
| 114 | |
| 115 | // C++ 5.2.3p1: |
| 116 | // If the expression list specifies more than a single value, the type shall |
| 117 | // be a class with a suitably declared constructor. |
| 118 | // |
| 119 | if (NumExprs > 1) |
| 120 | return Diag(CommaLocs[0], diag::err_builtin_func_cast_more_than_one_arg, |
| 121 | FullRange); |
| 122 | |
| 123 | assert(NumExprs == 0 && "Expected 0 expressions"); |
| 124 | |
| 125 | // C++ 5.2.3p2: |
| 126 | // The expression T(), where T is a simple-type-specifier for a non-array |
| 127 | // complete object type or the (possibly cv-qualified) void type, creates an |
| 128 | // rvalue of the specified type, which is value-initialized. |
| 129 | // |
| 130 | if (Ty->isArrayType()) |
| 131 | return Diag(TyBeginLoc, diag::err_value_init_for_array_type, FullRange); |
| 132 | if (Ty->isIncompleteType() && !Ty->isVoidType()) |
| 133 | return Diag(TyBeginLoc, diag::err_invalid_incomplete_type_use, |
| 134 | Ty.getAsString(), FullRange); |
| 135 | |
| 136 | return new CXXZeroInitValueExpr(Ty, TyBeginLoc, RParenLoc); |
| 137 | } |
Argyrios Kyrtzidis | 5921093 | 2008-09-10 02:17:11 +0000 | [diff] [blame] | 138 | |
| 139 | |
| 140 | /// ActOnCXXConditionDeclarationExpr - Parsed a condition declaration of a |
| 141 | /// C++ if/switch/while/for statement. |
| 142 | /// e.g: "if (int x = f()) {...}" |
| 143 | Action::ExprResult |
| 144 | Sema::ActOnCXXConditionDeclarationExpr(Scope *S, SourceLocation StartLoc, |
| 145 | Declarator &D, |
| 146 | SourceLocation EqualLoc, |
| 147 | ExprTy *AssignExprVal) { |
| 148 | assert(AssignExprVal && "Null assignment expression"); |
| 149 | |
| 150 | // C++ 6.4p2: |
| 151 | // The declarator shall not specify a function or an array. |
| 152 | // The type-specifier-seq shall not contain typedef and shall not declare a |
| 153 | // new class or enumeration. |
| 154 | |
| 155 | assert(D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_typedef && |
| 156 | "Parser allowed 'typedef' as storage class of condition decl."); |
| 157 | |
| 158 | QualType Ty = GetTypeForDeclarator(D, S); |
| 159 | |
| 160 | if (Ty->isFunctionType()) { // The declarator shall not specify a function... |
| 161 | // We exit without creating a CXXConditionDeclExpr because a FunctionDecl |
| 162 | // would be created and CXXConditionDeclExpr wants a VarDecl. |
| 163 | return Diag(StartLoc, diag::err_invalid_use_of_function_type, |
| 164 | SourceRange(StartLoc, EqualLoc)); |
| 165 | } else if (Ty->isArrayType()) { // ...or an array. |
| 166 | Diag(StartLoc, diag::err_invalid_use_of_array_type, |
| 167 | SourceRange(StartLoc, EqualLoc)); |
| 168 | } else if (const RecordType *RT = Ty->getAsRecordType()) { |
| 169 | RecordDecl *RD = RT->getDecl(); |
| 170 | // The type-specifier-seq shall not declare a new class... |
| 171 | if (RD->isDefinition() && (RD->getIdentifier() == 0 || S->isDeclScope(RD))) |
| 172 | Diag(RD->getLocation(), diag::err_type_defined_in_condition); |
| 173 | } else if (const EnumType *ET = Ty->getAsEnumType()) { |
| 174 | EnumDecl *ED = ET->getDecl(); |
| 175 | // ...or enumeration. |
| 176 | if (ED->isDefinition() && (ED->getIdentifier() == 0 || S->isDeclScope(ED))) |
| 177 | Diag(ED->getLocation(), diag::err_type_defined_in_condition); |
| 178 | } |
| 179 | |
| 180 | DeclTy *Dcl = ActOnDeclarator(S, D, 0); |
| 181 | if (!Dcl) |
| 182 | return true; |
| 183 | AddInitializerToDecl(Dcl, AssignExprVal); |
| 184 | |
| 185 | return new CXXConditionDeclExpr(StartLoc, EqualLoc, |
| 186 | cast<VarDecl>(static_cast<Decl *>(Dcl))); |
| 187 | } |
| 188 | |
| 189 | /// CheckCXXBooleanCondition - Returns true if a conversion to bool is invalid. |
| 190 | bool Sema::CheckCXXBooleanCondition(Expr *&CondExpr) { |
| 191 | // C++ 6.4p4: |
| 192 | // The value of a condition that is an initialized declaration in a statement |
| 193 | // other than a switch statement is the value of the declared variable |
| 194 | // implicitly converted to type bool. If that conversion is ill-formed, the |
| 195 | // program is ill-formed. |
| 196 | // The value of a condition that is an expression is the value of the |
| 197 | // expression, implicitly converted to bool. |
| 198 | // |
| 199 | QualType Ty = CondExpr->getType(); // Save the type. |
| 200 | AssignConvertType |
| 201 | ConvTy = CheckSingleAssignmentConstraints(Context.BoolTy, CondExpr); |
| 202 | if (ConvTy == Incompatible) |
| 203 | return Diag(CondExpr->getLocStart(), diag::err_typecheck_bool_condition, |
| 204 | Ty.getAsString(), CondExpr->getSourceRange()); |
| 205 | return false; |
| 206 | } |
Douglas Gregor | 77a5223 | 2008-09-12 00:47:35 +0000 | [diff] [blame] | 207 | |
| 208 | /// Helper function to determine whether this is the (deprecated) C++ |
| 209 | /// conversion from a string literal to a pointer to non-const char or |
| 210 | /// non-const wchar_t (for narrow and wide string literals, |
| 211 | /// respectively). |
| 212 | bool |
| 213 | Sema::IsStringLiteralToNonConstPointerConversion(Expr *From, QualType ToType) { |
| 214 | // Look inside the implicit cast, if it exists. |
| 215 | if (ImplicitCastExpr *Cast = dyn_cast<ImplicitCastExpr>(From)) |
| 216 | From = Cast->getSubExpr(); |
| 217 | |
| 218 | // A string literal (2.13.4) that is not a wide string literal can |
| 219 | // be converted to an rvalue of type "pointer to char"; a wide |
| 220 | // string literal can be converted to an rvalue of type "pointer |
| 221 | // to wchar_t" (C++ 4.2p2). |
| 222 | if (StringLiteral *StrLit = dyn_cast<StringLiteral>(From)) |
| 223 | if (const PointerType *ToPtrType = ToType->getAsPointerType()) |
| 224 | if (const BuiltinType *ToPointeeType |
| 225 | = ToPtrType->getPointeeType()->getAsBuiltinType()) { |
| 226 | // This conversion is considered only when there is an |
| 227 | // explicit appropriate pointer target type (C++ 4.2p2). |
| 228 | if (ToPtrType->getPointeeType().getCVRQualifiers() == 0 && |
| 229 | ((StrLit->isWide() && ToPointeeType->isWideCharType()) || |
| 230 | (!StrLit->isWide() && |
| 231 | (ToPointeeType->getKind() == BuiltinType::Char_U || |
| 232 | ToPointeeType->getKind() == BuiltinType::Char_S)))) |
| 233 | return true; |
| 234 | } |
| 235 | |
| 236 | return false; |
| 237 | } |
Douglas Gregor | 94b1dd2 | 2008-10-24 04:54:22 +0000 | [diff] [blame^] | 238 | |
| 239 | /// PerformImplicitConversion - Perform an implicit conversion of the |
| 240 | /// expression From to the type ToType. Returns true if there was an |
| 241 | /// error, false otherwise. The expression From is replaced with the |
| 242 | /// converted expression. |
| 243 | bool |
| 244 | Sema::PerformImplicitConversion(Expr *&From, QualType ToType) |
| 245 | { |
| 246 | ImplicitConversionSequence ICS = TryCopyInitialization(From, ToType); |
| 247 | switch (ICS.ConversionKind) { |
| 248 | case ImplicitConversionSequence::StandardConversion: |
| 249 | if (PerformImplicitConversion(From, ToType, ICS.Standard)) |
| 250 | return true; |
| 251 | break; |
| 252 | |
| 253 | case ImplicitConversionSequence::UserDefinedConversion: |
| 254 | // FIXME: This is, of course, wrong. We'll need to actually call |
| 255 | // the constructor or conversion operator, and then cope with the |
| 256 | // standard conversions. |
| 257 | ImpCastExprToType(From, ToType); |
| 258 | break; |
| 259 | |
| 260 | case ImplicitConversionSequence::EllipsisConversion: |
| 261 | assert(false && "Cannot perform an ellipsis conversion"); |
| 262 | break; |
| 263 | |
| 264 | case ImplicitConversionSequence::BadConversion: |
| 265 | return true; |
| 266 | } |
| 267 | |
| 268 | // Everything went well. |
| 269 | return false; |
| 270 | } |
| 271 | |
| 272 | /// PerformImplicitConversion - Perform an implicit conversion of the |
| 273 | /// expression From to the type ToType by following the standard |
| 274 | /// conversion sequence SCS. Returns true if there was an error, false |
| 275 | /// otherwise. The expression From is replaced with the converted |
| 276 | /// expression. |
| 277 | bool |
| 278 | Sema::PerformImplicitConversion(Expr *&From, QualType ToType, |
| 279 | const StandardConversionSequence& SCS) |
| 280 | { |
| 281 | // Overall FIXME: we are recomputing too many types here and doing |
| 282 | // far too much extra work. What this means is that we need to keep |
| 283 | // track of more information that is computed when we try the |
| 284 | // implicit conversion initially, so that we don't need to recompute |
| 285 | // anything here. |
| 286 | QualType FromType = From->getType(); |
| 287 | |
| 288 | // Perform the first implicit conversion. |
| 289 | switch (SCS.First) { |
| 290 | case ICK_Identity: |
| 291 | case ICK_Lvalue_To_Rvalue: |
| 292 | // Nothing to do. |
| 293 | break; |
| 294 | |
| 295 | case ICK_Array_To_Pointer: |
| 296 | FromType = Context.getArrayDecayedType(FromType); |
| 297 | ImpCastExprToType(From, FromType); |
| 298 | break; |
| 299 | |
| 300 | case ICK_Function_To_Pointer: |
| 301 | FromType = Context.getPointerType(FromType); |
| 302 | ImpCastExprToType(From, FromType); |
| 303 | break; |
| 304 | |
| 305 | default: |
| 306 | assert(false && "Improper first standard conversion"); |
| 307 | break; |
| 308 | } |
| 309 | |
| 310 | // Perform the second implicit conversion |
| 311 | switch (SCS.Second) { |
| 312 | case ICK_Identity: |
| 313 | // Nothing to do. |
| 314 | break; |
| 315 | |
| 316 | case ICK_Integral_Promotion: |
| 317 | case ICK_Floating_Promotion: |
| 318 | case ICK_Integral_Conversion: |
| 319 | case ICK_Floating_Conversion: |
| 320 | case ICK_Floating_Integral: |
| 321 | FromType = ToType.getUnqualifiedType(); |
| 322 | ImpCastExprToType(From, FromType); |
| 323 | break; |
| 324 | |
| 325 | case ICK_Pointer_Conversion: |
| 326 | if (CheckPointerConversion(From, ToType)) |
| 327 | return true; |
| 328 | ImpCastExprToType(From, ToType); |
| 329 | break; |
| 330 | |
| 331 | case ICK_Pointer_Member: |
| 332 | // FIXME: Implement pointer-to-member conversions. |
| 333 | assert(false && "Pointer-to-member conversions are unsupported"); |
| 334 | break; |
| 335 | |
| 336 | case ICK_Boolean_Conversion: |
| 337 | FromType = Context.BoolTy; |
| 338 | ImpCastExprToType(From, FromType); |
| 339 | break; |
| 340 | |
| 341 | default: |
| 342 | assert(false && "Improper second standard conversion"); |
| 343 | break; |
| 344 | } |
| 345 | |
| 346 | switch (SCS.Third) { |
| 347 | case ICK_Identity: |
| 348 | // Nothing to do. |
| 349 | break; |
| 350 | |
| 351 | case ICK_Qualification: |
| 352 | ImpCastExprToType(From, ToType); |
| 353 | break; |
| 354 | |
| 355 | default: |
| 356 | assert(false && "Improper second standard conversion"); |
| 357 | break; |
| 358 | } |
| 359 | |
| 360 | return false; |
| 361 | } |
| 362 | |