1 //===--- SemaFixItUtils.cpp - Sema FixIts ---------------------------------===// 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 defines helper classes for generation of Sema FixItHints. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #include "clang/AST/ExprCXX.h" 15 #include "clang/AST/ExprObjC.h" 16 #include "clang/Lex/Preprocessor.h" 17 #include "clang/Sema/Sema.h" 18 #include "clang/Sema/SemaFixItUtils.h" 19 20 using namespace clang; 21 22 bool ConversionFixItGenerator::compareTypesSimple(CanQualType From, 23 CanQualType To, 24 Sema &S, 25 SourceLocation Loc, 26 ExprValueKind FromVK) { 27 if (!To.isAtLeastAsQualifiedAs(From)) 28 return false; 29 30 From = From.getNonReferenceType(); 31 To = To.getNonReferenceType(); 32 33 // If both are pointer types, work with the pointee types. 34 if (isa<PointerType>(From) && isa<PointerType>(To)) { 35 From = S.Context.getCanonicalType( 36 (cast<PointerType>(From))->getPointeeType()); 37 To = S.Context.getCanonicalType( 38 (cast<PointerType>(To))->getPointeeType()); 39 } 40 41 const CanQualType FromUnq = From.getUnqualifiedType(); 42 const CanQualType ToUnq = To.getUnqualifiedType(); 43 44 if ((FromUnq == ToUnq || (S.IsDerivedFrom(FromUnq, ToUnq)) ) && 45 To.isAtLeastAsQualifiedAs(From)) 46 return true; 47 return false; 48 } 49 50 bool ConversionFixItGenerator::tryToFixConversion(const Expr *FullExpr, 51 const QualType FromTy, 52 const QualType ToTy, 53 Sema &S) { 54 if (!FullExpr) 55 return false; 56 57 const CanQualType FromQTy = S.Context.getCanonicalType(FromTy); 58 const CanQualType ToQTy = S.Context.getCanonicalType(ToTy); 59 const SourceLocation Begin = FullExpr->getSourceRange().getBegin(); 60 const SourceLocation End = S.PP.getLocForEndOfToken(FullExpr->getSourceRange() 61 .getEnd()); 62 63 // Strip the implicit casts - those are implied by the compiler, not the 64 // original source code. 65 const Expr* Expr = FullExpr->IgnoreImpCasts(); 66 67 bool NeedParen = true; 68 if (isa<ArraySubscriptExpr>(Expr) || 69 isa<CallExpr>(Expr) || 70 isa<DeclRefExpr>(Expr) || 71 isa<CastExpr>(Expr) || 72 isa<CXXNewExpr>(Expr) || 73 isa<CXXConstructExpr>(Expr) || 74 isa<CXXDeleteExpr>(Expr) || 75 isa<CXXNoexceptExpr>(Expr) || 76 isa<CXXPseudoDestructorExpr>(Expr) || 77 isa<CXXScalarValueInitExpr>(Expr) || 78 isa<CXXThisExpr>(Expr) || 79 isa<CXXTypeidExpr>(Expr) || 80 isa<CXXUnresolvedConstructExpr>(Expr) || 81 isa<ObjCMessageExpr>(Expr) || 82 isa<ObjCPropertyRefExpr>(Expr) || 83 isa<ObjCProtocolExpr>(Expr) || 84 isa<MemberExpr>(Expr) || 85 isa<ParenExpr>(FullExpr) || 86 isa<ParenListExpr>(Expr) || 87 isa<SizeOfPackExpr>(Expr) || 88 isa<UnaryOperator>(Expr)) 89 NeedParen = false; 90 91 // Check if the argument needs to be dereferenced: 92 // (type * -> type) or (type * -> type &). 93 if (const PointerType *FromPtrTy = dyn_cast<PointerType>(FromQTy)) { 94 OverloadFixItKind FixKind = OFIK_Dereference; 95 96 bool CanConvert = CompareTypes( 97 S.Context.getCanonicalType(FromPtrTy->getPointeeType()), ToQTy, 98 S, Begin, VK_LValue); 99 if (CanConvert) { 100 // Do not suggest dereferencing a Null pointer. 101 if (Expr->IgnoreParenCasts()-> 102 isNullPointerConstant(S.Context, Expr::NPC_ValueDependentIsNotNull)) 103 return false; 104 105 if (const UnaryOperator *UO = dyn_cast<UnaryOperator>(Expr)) { 106 if (UO->getOpcode() == UO_AddrOf) { 107 FixKind = OFIK_RemoveTakeAddress; 108 Hints.push_back(FixItHint::CreateRemoval( 109 CharSourceRange::getTokenRange(Begin, Begin))); 110 } 111 } else if (NeedParen) { 112 Hints.push_back(FixItHint::CreateInsertion(Begin, "*(")); 113 Hints.push_back(FixItHint::CreateInsertion(End, ")")); 114 } else { 115 Hints.push_back(FixItHint::CreateInsertion(Begin, "*")); 116 } 117 118 NumConversionsFixed++; 119 if (NumConversionsFixed == 1) 120 Kind = FixKind; 121 return true; 122 } 123 } 124 125 // Check if the pointer to the argument needs to be passed: 126 // (type -> type *) or (type & -> type *). 127 if (isa<PointerType>(ToQTy)) { 128 bool CanConvert = false; 129 OverloadFixItKind FixKind = OFIK_TakeAddress; 130 131 // Only suggest taking address of L-values. 132 if (!Expr->isLValue() || Expr->getObjectKind() != OK_Ordinary) 133 return false; 134 135 CanConvert = CompareTypes(S.Context.getPointerType(FromQTy), ToQTy, 136 S, Begin, VK_RValue); 137 if (CanConvert) { 138 139 if (const UnaryOperator *UO = dyn_cast<UnaryOperator>(Expr)) { 140 if (UO->getOpcode() == UO_Deref) { 141 FixKind = OFIK_RemoveDereference; 142 Hints.push_back(FixItHint::CreateRemoval( 143 CharSourceRange::getTokenRange(Begin, Begin))); 144 } 145 } else if (NeedParen) { 146 Hints.push_back(FixItHint::CreateInsertion(Begin, "&(")); 147 Hints.push_back(FixItHint::CreateInsertion(End, ")")); 148 } else { 149 Hints.push_back(FixItHint::CreateInsertion(Begin, "&")); 150 } 151 152 NumConversionsFixed++; 153 if (NumConversionsFixed == 1) 154 Kind = FixKind; 155 return true; 156 } 157 } 158 159 return false; 160 } 161 162 static bool isMacroDefined(const Sema &S, StringRef Name) { 163 return S.PP.getMacroInfo(&S.getASTContext().Idents.get(Name)); 164 } 165 166 const char *Sema::getFixItZeroInitializerForType(QualType T) const { 167 if (T->isScalarType()) { 168 // Suggest " = 0" for non-enumeration scalar types, unless we can find a 169 // better initializer. 170 if (T->isEnumeralType()) 171 return 0; 172 if ((T->isObjCObjectPointerType() || T->isBlockPointerType()) && 173 isMacroDefined(*this, "nil")) 174 return " = nil"; 175 if (T->isRealFloatingType()) 176 return " = 0.0"; 177 if (T->isBooleanType() && LangOpts.CPlusPlus) 178 return " = false"; 179 if (T->isPointerType() || T->isMemberPointerType()) { 180 if (LangOpts.CPlusPlus0x) 181 return " = nullptr"; 182 else if (isMacroDefined(*this, "NULL")) 183 return " = NULL"; 184 } 185 if (T->isCharType()) 186 return " = '\\0'"; 187 if (T->isWideCharType()) 188 return " = L'\\0'"; 189 if (T->isChar16Type()) 190 return " = u'\\0'"; 191 if (T->isChar32Type()) 192 return " = U'\\0'"; 193 return " = 0"; 194 } 195 196 const CXXRecordDecl *RD = T->getAsCXXRecordDecl(); 197 if (!RD || !RD->hasDefinition()) 198 return 0; 199 if (LangOpts.CPlusPlus0x && !RD->hasUserProvidedDefaultConstructor()) 200 return "{}"; 201 if (RD->isAggregate()) 202 return " = {}"; 203 return 0; 204 } 205
