[cfe-commits] r56137 - in /cfe/trunk: include/clang/AST/Type.h lib/AST/Type.cpp lib/Sema/Sema.h lib/Sema/SemaExpr.cpp lib/Sema/SemaExprCXX.cpp test/SemaCXX/type-convert-construct.cpp
Douglas Gregor
doug.gregor at gmail.com
Thu Sep 11 17:47:35 PDT 2008
Author: dgregor
Date: Thu Sep 11 19:47:35 2008
New Revision: 56137
URL: http://llvm.org/viewvc/llvm-project?rev=56137&view=rev
Log:
Give string literals const element typesin C++, and cope with the deprecated C++ conversion from a string literal to a pointer-to-non-const-character
Modified:
cfe/trunk/include/clang/AST/Type.h
cfe/trunk/lib/AST/Type.cpp
cfe/trunk/lib/Sema/Sema.h
cfe/trunk/lib/Sema/SemaExpr.cpp
cfe/trunk/lib/Sema/SemaExprCXX.cpp
cfe/trunk/test/SemaCXX/type-convert-construct.cpp
Modified: cfe/trunk/include/clang/AST/Type.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/AST/Type.h?rev=56137&r1=56136&r2=56137&view=diff
==============================================================================
--- cfe/trunk/include/clang/AST/Type.h (original)
+++ cfe/trunk/include/clang/AST/Type.h Thu Sep 11 19:47:35 2008
@@ -302,6 +302,7 @@
bool isEnumeralType() const;
bool isBooleanType() const;
bool isCharType() const;
+ bool isWideCharType() const;
bool isIntegralType() const;
/// Floating point categories.
Modified: cfe/trunk/lib/AST/Type.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/Type.cpp?rev=56137&r1=56136&r2=56137&view=diff
==============================================================================
--- cfe/trunk/lib/AST/Type.cpp (original)
+++ cfe/trunk/lib/AST/Type.cpp Thu Sep 11 19:47:35 2008
@@ -498,6 +498,14 @@
return false;
}
+bool Type::isWideCharType() const {
+ if (const BuiltinType *BT = dyn_cast<BuiltinType>(CanonicalType))
+ return BT->getKind() == BuiltinType::WChar;
+ if (const ASQualType *ASQT = dyn_cast<ASQualType>(CanonicalType))
+ return ASQT->getBaseType()->isWideCharType();
+ return false;
+}
+
/// isSignedIntegerType - Return true if this is an integer type that is
/// signed, according to C99 6.2.5p4 [char, signed char, short, int, long..],
/// an enum decl which has a signed representation, or a vector of signed
Modified: cfe/trunk/lib/Sema/Sema.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/Sema.h?rev=56137&r1=56136&r2=56137&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/Sema.h (original)
+++ cfe/trunk/lib/Sema/Sema.h Thu Sep 11 19:47:35 2008
@@ -890,6 +890,8 @@
// blcok pointer types.
AssignConvertType CheckBlockPointerTypesForAssignment(QualType lhsType,
QualType rhsType);
+
+ bool IsStringLiteralToNonConstPointerConversion(Expr *From, QualType ToType);
/// the following "Check" methods will return a valid/converted QualType
/// or a null QualType (indicating an error diagnostic was issued).
Modified: cfe/trunk/lib/Sema/SemaExpr.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaExpr.cpp?rev=56137&r1=56136&r2=56137&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaExpr.cpp (original)
+++ cfe/trunk/lib/Sema/SemaExpr.cpp Thu Sep 11 19:47:35 2008
@@ -290,6 +290,10 @@
QualType StrTy = Context.CharTy;
if (Literal.AnyWide) StrTy = Context.getWCharType();
if (Literal.Pascal) StrTy = Context.UnsignedCharTy;
+
+ // A C++ string literal has a const-qualified element type (C++ 2.13.4p1).
+ if (getLangOptions().CPlusPlus)
+ StrTy.addConst();
// Get an array type for the string, according to C99 6.4.5. This includes
// the nul terminator character as well as the string length for pascal
@@ -3066,6 +3070,18 @@
DiagKind = diag::ext_typecheck_convert_pointer_void_func;
break;
case CompatiblePointerDiscardsQualifiers:
+ // If the qualifiers lost were because we were applying the
+ // (deprecated) C++ conversion from a string literal to a char*
+ // (or wchar_t*), then there was no error (C++ 4.2p2). FIXME:
+ // Ideally, this check would be performed in
+ // CheckPointerTypesForAssignment. However, that would require a
+ // bit of refactoring (so that the second argument is an
+ // expression, rather than a type), which should be done as part
+ // of a larger effort to fix CheckPointerTypesForAssignment for
+ // C++ semantics.
+ if (getLangOptions().CPlusPlus &&
+ IsStringLiteralToNonConstPointerConversion(SrcExpr, DstType))
+ return false;
DiagKind = diag::ext_typecheck_convert_discards_qualifiers;
break;
case IntToBlockPointer:
Modified: cfe/trunk/lib/Sema/SemaExprCXX.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaExprCXX.cpp?rev=56137&r1=56136&r2=56137&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaExprCXX.cpp (original)
+++ cfe/trunk/lib/Sema/SemaExprCXX.cpp Thu Sep 11 19:47:35 2008
@@ -202,3 +202,34 @@
Ty.getAsString(), CondExpr->getSourceRange());
return false;
}
+
+/// Helper function to determine whether this is the (deprecated) C++
+/// conversion from a string literal to a pointer to non-const char or
+/// non-const wchar_t (for narrow and wide string literals,
+/// respectively).
+bool
+Sema::IsStringLiteralToNonConstPointerConversion(Expr *From, QualType ToType) {
+ // Look inside the implicit cast, if it exists.
+ if (ImplicitCastExpr *Cast = dyn_cast<ImplicitCastExpr>(From))
+ From = Cast->getSubExpr();
+
+ // A string literal (2.13.4) that is not a wide string literal can
+ // be converted to an rvalue of type "pointer to char"; a wide
+ // string literal can be converted to an rvalue of type "pointer
+ // to wchar_t" (C++ 4.2p2).
+ if (StringLiteral *StrLit = dyn_cast<StringLiteral>(From))
+ if (const PointerType *ToPtrType = ToType->getAsPointerType())
+ if (const BuiltinType *ToPointeeType
+ = ToPtrType->getPointeeType()->getAsBuiltinType()) {
+ // This conversion is considered only when there is an
+ // explicit appropriate pointer target type (C++ 4.2p2).
+ if (ToPtrType->getPointeeType().getCVRQualifiers() == 0 &&
+ ((StrLit->isWide() && ToPointeeType->isWideCharType()) ||
+ (!StrLit->isWide() &&
+ (ToPointeeType->getKind() == BuiltinType::Char_U ||
+ ToPointeeType->getKind() == BuiltinType::Char_S))))
+ return true;
+ }
+
+ return false;
+}
Modified: cfe/trunk/test/SemaCXX/type-convert-construct.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/type-convert-construct.cpp?rev=56137&r1=56136&r2=56137&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/type-convert-construct.cpp (original)
+++ cfe/trunk/test/SemaCXX/type-convert-construct.cpp Thu Sep 11 19:47:35 2008
@@ -10,4 +10,8 @@
typedef int T;
int *p;
bool v6 = T(0) == p;
+ char *str;
+ str = "a string";
+ wchar_t *wstr;
+ wstr = L"a wide string";
}
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