r199513 - Fix string-literal to char* conversion in overload resolution for C++11
Ismail Pazarbasi
ismail.pazarbasi at gmail.com
Fri Jan 17 13:08:52 PST 2014
Author: ismailp
Date: Fri Jan 17 15:08:52 2014
New Revision: 199513
URL: http://llvm.org/viewvc/llvm-project?rev=199513&view=rev
Log:
Fix string-literal to char* conversion in overload resolution for C++11
String literal to char* conversion is deprecated in C++03, and is removed in
C++11. We still accept this conversion in C++11 mode as an extension, if we find
it in the best viable function.
Modified:
cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
cfe/trunk/lib/Sema/SemaExprCXX.cpp
cfe/trunk/lib/Sema/SemaOverload.cpp
cfe/trunk/test/SemaCXX/cxx0x-type-convert-construct.cpp
cfe/trunk/test/SemaCXX/deprecated.cpp
cfe/trunk/test/SemaCXX/overload-0x.cpp
cfe/trunk/unittests/ASTMatchers/ASTMatchersTest.cpp
Modified: cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td?rev=199513&r1=199512&r2=199513&view=diff
==============================================================================
--- cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td (original)
+++ cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td Fri Jan 17 15:08:52 2014
@@ -4534,6 +4534,9 @@ def ext_array_init_parens : ExtWarn<
def warn_deprecated_string_literal_conversion : Warning<
"conversion from string literal to %0 is deprecated">,
InGroup<CXX11CompatDeprecatedWritableStr>;
+def ext_deprecated_string_literal_conversion : ExtWarn<
+ "ISO C++11 does not allow conversion from string literal to %0">,
+ InGroup<CXX11CompatDeprecatedWritableStr>, SFINAEFailure;
def warn_deprecated_string_literal_conversion_c : Warning<
"dummy warning to enable -fconst-strings">, InGroup<DeprecatedWritableStr>, DefaultIgnore;
def err_realimag_invalid_type : Error<"invalid type %0 to %1 operator">;
Modified: cfe/trunk/lib/Sema/SemaExprCXX.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaExprCXX.cpp?rev=199513&r1=199512&r2=199513&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaExprCXX.cpp (original)
+++ cfe/trunk/lib/Sema/SemaExprCXX.cpp Fri Jan 17 15:08:52 2014
@@ -3058,9 +3058,12 @@ Sema::PerformImplicitConversion(Expr *Fr
CK_NoOp, VK, /*BasePath=*/0, CCK).take();
if (SCS.DeprecatedStringLiteralToCharPtr &&
- !getLangOpts().WritableStrings)
- Diag(From->getLocStart(), diag::warn_deprecated_string_literal_conversion)
+ !getLangOpts().WritableStrings) {
+ Diag(From->getLocStart(), getLangOpts().CPlusPlus11
+ ? diag::ext_deprecated_string_literal_conversion
+ : diag::warn_deprecated_string_literal_conversion)
<< ToType.getNonReferenceType();
+ }
break;
}
Modified: cfe/trunk/lib/Sema/SemaOverload.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaOverload.cpp?rev=199513&r1=199512&r2=199513&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaOverload.cpp (original)
+++ cfe/trunk/lib/Sema/SemaOverload.cpp Fri Jan 17 15:08:52 2014
@@ -1443,7 +1443,6 @@ static bool IsStandardConversion(Sema &S
// Standard conversions (C++ [conv])
SCS.setAsIdentityConversion();
- SCS.DeprecatedStringLiteralToCharPtr = false;
SCS.IncompatibleObjC = false;
SCS.setFromType(FromType);
SCS.CopyConstructor = 0;
@@ -1542,7 +1541,7 @@ static bool IsStandardConversion(Sema &S
FromType = S.Context.getArrayDecayedType(FromType);
if (S.IsStringLiteralToNonConstPointerConversion(From, ToType)) {
- // This conversion is deprecated. (C++ D.4).
+ // This conversion is deprecated in C++03 (D.4)
SCS.DeprecatedStringLiteralToCharPtr = true;
// For the purpose of ranking in overload resolution
@@ -3259,18 +3258,15 @@ Sema::DiagnoseMultipleUserDefinedConvers
IsUserDefinedConversion(*this, From, ToType, ICS.UserDefined,
CandidateSet, false, false);
if (OvResult == OR_Ambiguous)
- Diag(From->getLocStart(),
- diag::err_typecheck_ambiguous_condition)
- << From->getType() << ToType << From->getSourceRange();
+ Diag(From->getLocStart(), diag::err_typecheck_ambiguous_condition)
+ << From->getType() << ToType << From->getSourceRange();
else if (OvResult == OR_No_Viable_Function && !CandidateSet.empty()) {
if (!RequireCompleteType(From->getLocStart(), ToType,
- diag::err_typecheck_nonviable_condition_incomplete,
+ diag::err_typecheck_nonviable_condition_incomplete,
From->getType(), From->getSourceRange()))
- Diag(From->getLocStart(),
- diag::err_typecheck_nonviable_condition)
- << From->getType() << From->getSourceRange() << ToType;
- }
- else
+ Diag(From->getLocStart(), diag::err_typecheck_nonviable_condition)
+ << From->getType() << From->getSourceRange() << ToType;
+ } else
return false;
CandidateSet.NoteCandidates(*this, OCD_AllCandidates, From);
return true;
@@ -3280,37 +3276,43 @@ Sema::DiagnoseMultipleUserDefinedConvers
/// of two user-defined conversion sequences to determine whether any ordering
/// is possible.
static ImplicitConversionSequence::CompareKind
-compareConversionFunctions(Sema &S,
- FunctionDecl *Function1,
+compareConversionFunctions(Sema &S, FunctionDecl *Function1,
FunctionDecl *Function2) {
if (!S.getLangOpts().ObjC1 || !S.getLangOpts().CPlusPlus11)
return ImplicitConversionSequence::Indistinguishable;
-
+
// Objective-C++:
// If both conversion functions are implicitly-declared conversions from
- // a lambda closure type to a function pointer and a block pointer,
+ // a lambda closure type to a function pointer and a block pointer,
// respectively, always prefer the conversion to a function pointer,
// because the function pointer is more lightweight and is more likely
// to keep code working.
CXXConversionDecl *Conv1 = dyn_cast<CXXConversionDecl>(Function1);
if (!Conv1)
return ImplicitConversionSequence::Indistinguishable;
-
+
CXXConversionDecl *Conv2 = dyn_cast<CXXConversionDecl>(Function2);
if (!Conv2)
return ImplicitConversionSequence::Indistinguishable;
-
+
if (Conv1->getParent()->isLambda() && Conv2->getParent()->isLambda()) {
bool Block1 = Conv1->getConversionType()->isBlockPointerType();
bool Block2 = Conv2->getConversionType()->isBlockPointerType();
if (Block1 != Block2)
- return Block1? ImplicitConversionSequence::Worse
- : ImplicitConversionSequence::Better;
+ return Block1 ? ImplicitConversionSequence::Worse
+ : ImplicitConversionSequence::Better;
}
return ImplicitConversionSequence::Indistinguishable;
}
-
+
+static bool hasDeprecatedStringLiteralToCharPtrConversion(
+ const ImplicitConversionSequence &ICS) {
+ return (ICS.isStandard() && ICS.Standard.DeprecatedStringLiteralToCharPtr) ||
+ (ICS.isUserDefined() &&
+ ICS.UserDefined.Before.DeprecatedStringLiteralToCharPtr);
+}
+
/// CompareImplicitConversionSequences - Compare two implicit
/// conversion sequences to determine whether one is better than the
/// other or if they are indistinguishable (C++ 13.3.3.2).
@@ -3333,6 +3335,32 @@ CompareImplicitConversionSequences(Sema
// described in 13.3.3.2, the ambiguous conversion sequence is
// treated as a user-defined sequence that is indistinguishable
// from any other user-defined conversion sequence.
+
+ // String literal to 'char *' conversion has been deprecated in C++03. It has
+ // been removed from C++11. We still accept this conversion, if it happens at
+ // the best viable function. Otherwise, this conversion is considered worse
+ // than ellipsis conversion. Consider this as an extension; this is not in the
+ // standard. For example:
+ //
+ // int &f(...); // #1
+ // void f(char*); // #2
+ // void g() { int &r = f("foo"); }
+ //
+ // In C++03, we pick #2 as the best viable function.
+ // In C++11, we pick #1 as the best viable function, because ellipsis
+ // conversion is better than string-literal to char* conversion (since there
+ // is no such conversion in C++11). If there was no #1 at all or #1 couldn't
+ // convert arguments, #2 would be the best viable function in C++11.
+ // If the best viable function has this conversion, a warning will be issued
+ // in C++03, or an ExtWarn (+SFINAE failure) will be issued in C++11.
+
+ if (S.getLangOpts().CPlusPlus11 && !S.getLangOpts().WritableStrings &&
+ hasDeprecatedStringLiteralToCharPtrConversion(ICS1) !=
+ hasDeprecatedStringLiteralToCharPtrConversion(ICS2))
+ return hasDeprecatedStringLiteralToCharPtrConversion(ICS1)
+ ? ImplicitConversionSequence::Worse
+ : ImplicitConversionSequence::Better;
+
if (ICS1.getKindRank() < ICS2.getKindRank())
return ImplicitConversionSequence::Better;
if (ICS2.getKindRank() < ICS1.getKindRank())
@@ -4244,6 +4272,7 @@ TryReferenceInit(Sema &S, Expr *Init, Qu
ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false;
ICS.Standard.ObjCLifetimeConversionBinding = ObjCLifetimeConversion;
ICS.Standard.CopyConstructor = 0;
+ ICS.Standard.DeprecatedStringLiteralToCharPtr = false;
// Nothing more to do: the inaccessibility/ambiguity check for
// derived-to-base conversions is suppressed when we're
@@ -4318,6 +4347,7 @@ TryReferenceInit(Sema &S, Expr *Init, Qu
ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false;
ICS.Standard.ObjCLifetimeConversionBinding = ObjCLifetimeConversion;
ICS.Standard.CopyConstructor = 0;
+ ICS.Standard.DeprecatedStringLiteralToCharPtr = false;
return ICS;
}
Modified: cfe/trunk/test/SemaCXX/cxx0x-type-convert-construct.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/cxx0x-type-convert-construct.cpp?rev=199513&r1=199512&r2=199513&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/cxx0x-type-convert-construct.cpp (original)
+++ cfe/trunk/test/SemaCXX/cxx0x-type-convert-construct.cpp Fri Jan 17 15:08:52 2014
@@ -9,9 +9,9 @@ void f() {
Ustr = U"a UTF-32 string"; // expected-error {{assigning to 'char32_t *' from incompatible type 'const char32_t [16]'}}
char *Rstr;
- Rstr = R"foo(a raw string)foo"; // expected-warning{{conversion from string literal to 'char *' is deprecated}}
+ Rstr = R"foo(a raw string)foo"; // expected-warning{{ISO C++11 does not allow conversion from string literal to 'char *'}}
wchar_t *LRstr;
- LRstr = LR"foo(a wide raw string)foo"; // expected-warning{{conversion from string literal to 'wchar_t *' is deprecated}}
+ LRstr = LR"foo(a wide raw string)foo"; // expected-warning{{ISO C++11 does not allow conversion from string literal to 'wchar_t *'}}
char *u8Rstr;
u8Rstr = u8R"foo(a UTF-8 raw string)foo"; // expected-error {{assigning to 'char *' from incompatible type 'const char [19]'}}
char16_t *uRstr;
Modified: cfe/trunk/test/SemaCXX/deprecated.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/deprecated.cpp?rev=199513&r1=199512&r2=199513&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/deprecated.cpp (original)
+++ cfe/trunk/test/SemaCXX/deprecated.cpp Fri Jan 17 15:08:52 2014
@@ -24,12 +24,15 @@ void stuff() {
register int m asm("rbx"); // no-warning
int k = to_int(n); // no-warning
-
bool b;
++b; // expected-warning {{incrementing expression of type bool is deprecated}}
- // FIXME: This is ill-formed in C++11.
- char *p = "foo"; // expected-warning {{conversion from string literal to 'char *' is deprecated}}
+ char *p = "foo";
+#if __cplusplus < 201103L
+ // expected-warning at -2 {{conversion from string literal to 'char *' is deprecated}}
+#else
+ // expected-warning at -4 {{ISO C++11 does not allow conversion from string literal to 'char *'}}
+#endif
}
struct S { int n; };
Modified: cfe/trunk/test/SemaCXX/overload-0x.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/overload-0x.cpp?rev=199513&r1=199512&r2=199513&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/overload-0x.cpp (original)
+++ cfe/trunk/test/SemaCXX/overload-0x.cpp Fri Jan 17 15:08:52 2014
@@ -1,7 +1,11 @@
-// RUN: %clang_cc1 -fsyntax-only -std=c++11 -verify %s
+// RUN: %clang_cc1 -fsyntax-only -std=c++11 -verify %s
+// RUN: %clang_cc1 -fsyntax-only -verify %s
namespace test0 {
- struct A { // expected-note {{candidate function (the implicit copy assignment operator) not viable: 'this' argument has type 'const test0::A', but method is not marked const}} expected-note {{candidate function (the implicit move assignment operator) not viable: 'this' argument has type 'const test0::A', but method is not marked const}}
+ struct A { // expected-note {{candidate function (the implicit copy assignment operator) not viable: 'this' argument has type 'const test0::A', but method is not marked const}}
+#if __cplusplus >= 201103L
+ // expected-note at -2 {{candidate function (the implicit move assignment operator) not viable: 'this' argument has type 'const test0::A', but method is not marked const}}
+#endif
A &operator=(void*); // expected-note {{candidate function not viable: 'this' argument has type 'const test0::A', but method is not marked const}}
};
@@ -9,3 +13,79 @@ namespace test0 {
a = "help"; // expected-error {{no viable overloaded '='}}
}
}
+
+namespace PR16314 {
+ void f(char*);
+ int &f(...);
+ void x()
+ {
+ int &n = f("foo");
+#if __cplusplus < 201103L
+ // expected-warning at -2 {{conversion from string literal to 'char *' is deprecated}}
+ // expected-error at -3 {{non-const lvalue reference to type 'int' cannot bind to a temporary of type 'void'}}
+#endif
+ }
+}
+
+namespace warn_if_best {
+ int f(char *);
+ void f(double);
+ void x()
+ {
+ int n = f("foo");
+#if __cplusplus < 201103L
+ // expected-warning at -2 {{conversion from string literal to 'char *' is deprecated}}
+#else
+ // expected-warning at -4 {{ISO C++11 does not allow conversion from string literal to 'char *'}}
+#endif
+ }
+}
+
+namespace userdefined_vs_illformed {
+ struct X { X(const char *); };
+
+ void *f(char *p); // best for C++03
+ double f(X x); // best for C++11
+ void g()
+ {
+ double d = f("foo");
+#if __cplusplus < 201103L
+ // expected-warning at -2 {{conversion from string literal to 'char *' is deprecated}}
+ // expected-error at -3 {{cannot initialize a variable of type 'double' with an rvalue of type 'void *'}}
+#endif
+ }
+}
+
+namespace sfinae_test {
+ int f(int, char*);
+
+ template<int T>
+ struct S { typedef int type; };
+
+ template<>
+ struct S<sizeof(int)> { typedef void type; };
+
+ // C++11: SFINAE failure
+ // C++03: ok
+ template<typename T> int cxx11_ignored(T, typename S<sizeof(f(T(), "foo"))>::type *);
+#if __cplusplus < 201103L
+ // expected-warning at -2 {{conversion from string literal to 'char *' is deprecated}}
+#else
+ // expected-note at -4 {{candidate template ignored: substitution failure}}
+#endif
+
+ // C++11: better than latter
+ // C++03: worse than latter
+ template<typename T> void g(T, ...);
+ template<typename T> int g(T, typename S<sizeof(f(T(), "foo"))>::type *);
+#if __cplusplus < 201103L
+ // expected-warning at -2 {{conversion from string literal to 'char *' is deprecated}}
+#endif
+
+ int a = cxx11_ignored(0, 0);
+ int b = g(0, 0);
+#if __cplusplus >= 201103L
+ // expected-error at -3 {{no matching function for call to 'cxx11_ignored'}}
+ // expected-error at -3 {{cannot initialize a variable of type 'int' with an rvalue of type 'void'}}
+#endif
+}
Modified: cfe/trunk/unittests/ASTMatchers/ASTMatchersTest.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/unittests/ASTMatchers/ASTMatchersTest.cpp?rev=199513&r1=199512&r2=199513&view=diff
==============================================================================
--- cfe/trunk/unittests/ASTMatchers/ASTMatchersTest.cpp (original)
+++ cfe/trunk/unittests/ASTMatchers/ASTMatchersTest.cpp Fri Jan 17 15:08:52 2014
@@ -2608,13 +2608,13 @@ TEST(ReinterpretCast, DoesNotMatchOtherC
}
TEST(FunctionalCast, MatchesSimpleCase) {
- std::string foo_class = "class Foo { public: Foo(char*); };";
+ std::string foo_class = "class Foo { public: Foo(const char*); };";
EXPECT_TRUE(matches(foo_class + "void r() { Foo f = Foo(\"hello world\"); }",
functionalCastExpr()));
}
TEST(FunctionalCast, DoesNotMatchOtherCasts) {
- std::string FooClass = "class Foo { public: Foo(char*); };";
+ std::string FooClass = "class Foo { public: Foo(const char*); };";
EXPECT_TRUE(
notMatches(FooClass + "void r() { Foo f = (Foo) \"hello world\"; }",
functionalCastExpr()));
More information about the cfe-commits
mailing list