r201620 - PR13110: Add a -Wignored-qualifiers warning when ignoring a const, volatile, or
Richard Smith
richard-llvm at metafoo.co.uk
Tue Feb 18 16:13:28 PST 2014
Author: rsmith
Date: Tue Feb 18 18:13:27 2014
New Revision: 201620
URL: http://llvm.org/viewvc/llvm-project?rev=201620&view=rev
Log:
PR13110: Add a -Wignored-qualifiers warning when ignoring a const, volatile, or
_Atomic qualifier applied to a reference type.
Modified:
cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
cfe/trunk/lib/Sema/SemaType.cpp
cfe/trunk/test/CXX/dcl.decl/dcl.meaning/dcl.ref/p6-0x.cpp
cfe/trunk/test/CXX/drs/dr1xx.cpp
cfe/trunk/test/Parser/cxx-reference.cpp
cfe/trunk/test/Parser/cxx0x-rvalue-reference.cpp
cfe/trunk/test/SemaCXX/references.cpp
Modified: cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td?rev=201620&r1=201619&r2=201620&view=diff
==============================================================================
--- cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td (original)
+++ cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td Tue Feb 18 18:13:27 2014
@@ -3787,6 +3787,9 @@ def warn_typecheck_negative_array_new_si
InGroup<BadArrayNewLength>;
def warn_typecheck_function_qualifiers : Warning<
"qualifier on function type %0 has unspecified behavior">;
+def warn_typecheck_reference_qualifiers : Warning<
+ "'%0' qualifier on reference type %1 has no effect">,
+ InGroup<IgnoredQualifiers>;
def err_typecheck_invalid_restrict_not_pointer : Error<
"restrict requires a pointer or reference (%0 is invalid)">;
def err_typecheck_invalid_restrict_not_pointer_noarg : Error<
Modified: cfe/trunk/lib/Sema/SemaType.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaType.cpp?rev=201620&r1=201619&r2=201620&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaType.cpp (original)
+++ cfe/trunk/lib/Sema/SemaType.cpp Tue Feb 18 18:13:27 2014
@@ -1117,17 +1117,32 @@ static QualType ConvertDeclSpecToType(Ty
}
}
- // C++ [dcl.ref]p1:
+ // C++11 [dcl.ref]p1:
// Cv-qualified references are ill-formed except when the
- // cv-qualifiers are introduced through the use of a typedef
- // (7.1.3) or of a template type argument (14.3), in which
- // case the cv-qualifiers are ignored.
- // FIXME: Shouldn't we be checking SCS_typedef here?
+ // cv-qualifiers are introduced through the use of a typedef-name
+ // or decltype-specifier, in which case the cv-qualifiers are ignored.
+ //
+ // There don't appear to be any other contexts in which a cv-qualified
+ // reference type could be formed, so the 'ill-formed' clause here appears
+ // to never happen.
if (DS.getTypeSpecType() == DeclSpec::TST_typename &&
TypeQuals && Result->isReferenceType()) {
- TypeQuals &= ~DeclSpec::TQ_const;
- TypeQuals &= ~DeclSpec::TQ_volatile;
- TypeQuals &= ~DeclSpec::TQ_atomic;
+ // If this occurs outside a template instantiation, warn the user about
+ // it; they probably didn't mean to specify a redundant qualifier.
+ std::pair<DeclSpec::TQ, SourceLocation> Quals[] = {
+ { DeclSpec::TQ_const, DS.getConstSpecLoc() },
+ { DeclSpec::TQ_volatile, DS.getVolatileSpecLoc() },
+ { DeclSpec::TQ_atomic, DS.getAtomicSpecLoc() }
+ };
+ for (unsigned I = 0, N = llvm::array_lengthof(Quals); I != N; ++I) {
+ if (S.ActiveTemplateInstantiations.empty()) {
+ if (TypeQuals & Quals[I].first)
+ S.Diag(Quals[I].second, diag::warn_typecheck_reference_qualifiers)
+ << DeclSpec::getSpecifierName(Quals[I].first) << Result
+ << FixItHint::CreateRemoval(Quals[I].second);
+ }
+ TypeQuals &= ~Quals[I].first;
+ }
}
// C90 6.5.3 constraints: "The same type qualifier shall not appear more
Modified: cfe/trunk/test/CXX/dcl.decl/dcl.meaning/dcl.ref/p6-0x.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CXX/dcl.decl/dcl.meaning/dcl.ref/p6-0x.cpp?rev=201620&r1=201619&r2=201620&view=diff
==============================================================================
--- cfe/trunk/test/CXX/dcl.decl/dcl.meaning/dcl.ref/p6-0x.cpp (original)
+++ cfe/trunk/test/CXX/dcl.decl/dcl.meaning/dcl.ref/p6-0x.cpp Tue Feb 18 18:13:27 2014
@@ -1,5 +1,4 @@
// RUN: %clang_cc1 -std=c++11 -fsyntax-only -verify %s
-// expected-no-diagnostics
template<typename T, typename U>
struct is_same {
@@ -20,8 +19,8 @@ typedef int& LRI;
typedef int&& RRI;
typedef LRI& r1; CHECK_EQUAL_TYPES(r1, int&);
-typedef const LRI& r2; CHECK_EQUAL_TYPES(r2, int&);
-typedef const LRI&& r3; CHECK_EQUAL_TYPES(r3, int&);
+typedef const LRI& r2; CHECK_EQUAL_TYPES(r2, int&); // expected-warning {{'const' qualifier on reference type 'LRI' (aka 'int &') has no effect}}
+typedef const LRI&& r3; CHECK_EQUAL_TYPES(r3, int&); // expected-warning {{'const' qualifier on reference type 'LRI' (aka 'int &') has no effect}}
typedef RRI& r4; CHECK_EQUAL_TYPES(r4, int&);
typedef RRI&& r5; CHECK_EQUAL_TYPES(r5, int&&);
Modified: cfe/trunk/test/CXX/drs/dr1xx.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CXX/drs/dr1xx.cpp?rev=201620&r1=201619&r2=201620&view=diff
==============================================================================
--- cfe/trunk/test/CXX/drs/dr1xx.cpp (original)
+++ cfe/trunk/test/CXX/drs/dr1xx.cpp Tue Feb 18 18:13:27 2014
@@ -40,13 +40,13 @@ namespace dr102 { // dr102: yes
namespace dr106 { // dr106: sup 540
typedef int &r1;
typedef r1 &r1;
- typedef const r1 r1;
- typedef const r1 &r1;
+ typedef const r1 r1; // expected-warning {{has no effect}}
+ typedef const r1 &r1; // expected-warning {{has no effect}}
typedef const int &r2;
typedef r2 &r2;
- typedef const r2 r2;
- typedef const r2 &r2;
+ typedef const r2 r2; // expected-warning {{has no effect}}
+ typedef const r2 &r2; // expected-warning {{has no effect}}
}
namespace dr107 { // dr107: yes
Modified: cfe/trunk/test/Parser/cxx-reference.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Parser/cxx-reference.cpp?rev=201620&r1=201619&r2=201620&view=diff
==============================================================================
--- cfe/trunk/test/Parser/cxx-reference.cpp (original)
+++ cfe/trunk/test/Parser/cxx-reference.cpp Tue Feb 18 18:13:27 2014
@@ -10,7 +10,7 @@ void foo(int &a) {
typedef int & A;
-void g(const A aref) {
+void g(const A aref) { // expected-warning {{'const' qualifier on reference type 'A' (aka 'int &') has no effect}}
}
int & const X = val; // expected-error {{'const' qualifier may not be applied to a reference}}
Modified: cfe/trunk/test/Parser/cxx0x-rvalue-reference.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Parser/cxx0x-rvalue-reference.cpp?rev=201620&r1=201619&r2=201620&view=diff
==============================================================================
--- cfe/trunk/test/Parser/cxx0x-rvalue-reference.cpp (original)
+++ cfe/trunk/test/Parser/cxx0x-rvalue-reference.cpp Tue Feb 18 18:13:27 2014
@@ -3,7 +3,7 @@
int && r1(int &&a);
typedef int && R;
-void r2(const R a) {
+void r2(const R a) { // expected-warning {{'const' qualifier on reference type 'R' (aka 'int &&') has no effect}}
int & &&ar = a; // expected-error{{'ar' declared as a reference to a reference}}
}
Modified: cfe/trunk/test/SemaCXX/references.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/references.cpp?rev=201620&r1=201619&r2=201620&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/references.cpp (original)
+++ cfe/trunk/test/SemaCXX/references.cpp Tue Feb 18 18:13:27 2014
@@ -85,9 +85,19 @@ void test8(int& const,// expected-error{
typedef int& intref;
typedef intref& intrefref; // C++ DR 106: reference collapsing
- typedef intref const intref_c; // okay. FIXME: how do we verify that this is the same type as intref?
+ typedef intref const intref_c; // expected-warning {{'const' qualifier on reference type 'intref' (aka 'int &') has no effect}}
+ typedef intref_c intref; // ok, same type
+
+ typedef intref volatile intref; // expected-warning {{'volatile' qualifier on reference type 'intref' (aka 'int &') has no effect}}
+ typedef intref _Atomic intref; // expected-warning {{'_Atomic' qualifier on reference type 'intref' (aka 'int &') has no effect}}
+
+ void restrict_ref(__restrict intref); // ok
+ void restrict_ref(int &__restrict); // ok
}
+template<typename T> int const_param(const T) {}
+int const_ref_param = const_param<int&>(const_ref_param); // no-warning
+
class string {
char *Data;
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