* C++ PATCH for c++/59296 (rvalue object and lvalue ref-qualifier)
@ 2014-06-18 22:12 Jason Merrill
2014-06-19 9:32 ` Jason Merrill
2014-06-19 11:29 ` Marc Glisse
0 siblings, 2 replies; 5+ messages in thread
From: Jason Merrill @ 2014-06-18 22:12 UTC (permalink / raw)
To: gcc-patches List
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We were treating a const & member function like a normal const
reference, and binding an rvalue object argument to it. But it doesn't
work that way.
Tested x86_64-pc-linux-gnu, applying to trunk.
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commit 20a165532a9b0b0dada391716a1fb781af3ec005
Author: Jason Merrill <jason@redhat.com>
Date: Wed Jun 18 22:56:25 2014 +0200
PR c++/59296
* call.c (add_function_candidate): Set LOOKUP_NO_RVAL_BIND for
ref-qualifier handling.
diff --git a/gcc/cp/call.c b/gcc/cp/call.c
index 1d4c4f9..b4adf36 100644
--- a/gcc/cp/call.c
+++ b/gcc/cp/call.c
@@ -2025,6 +2025,8 @@ add_function_candidate (struct z_candidate **candidates,
object parameter has reference type. */
bool rv = FUNCTION_RVALUE_QUALIFIED (TREE_TYPE (fn));
parmtype = cp_build_reference_type (parmtype, rv);
+ /* Don't bind an rvalue to a const lvalue ref-qualifier. */
+ lflags |= LOOKUP_NO_RVAL_BIND;
}
else
{
diff --git a/gcc/testsuite/g++.dg/cpp0x/ref-qual15.C b/gcc/testsuite/g++.dg/cpp0x/ref-qual15.C
new file mode 100644
index 0000000..ca333c2
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/ref-qual15.C
@@ -0,0 +1,13 @@
+// PR c++/59296
+// { dg-do compile { target c++11 } }
+
+struct Type
+{
+ void get() const& { }
+ void get() const&& { }
+};
+
+int main()
+{
+ Type{}.get();
+}
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: C++ PATCH for c++/59296 (rvalue object and lvalue ref-qualifier)
2014-06-18 22:12 C++ PATCH for c++/59296 (rvalue object and lvalue ref-qualifier) Jason Merrill
@ 2014-06-19 9:32 ` Jason Merrill
2014-06-19 11:29 ` Marc Glisse
1 sibling, 0 replies; 5+ messages in thread
From: Jason Merrill @ 2014-06-19 9:32 UTC (permalink / raw)
To: gcc-patches List
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On 06/19/2014 12:12 AM, Jason Merrill wrote:
> We were treating a const & member function like a normal const
> reference, and binding an rvalue object argument to it. But it doesn't
> work that way.
In 4.9 we also need to set LOOKUP_NO_TEMP_BIND.
[-- Attachment #2: 59296-2.patch --]
[-- Type: text/x-patch, Size: 1183 bytes --]
commit 48ca9803695872d984b0f4efa56f7f58987d0928
Author: jason <jason@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Wed Jun 18 22:13:51 2014 +0000
PR c++/59296
* call.c (add_function_candidate): Set LOOKUP_NO_RVAL_BIND
|LOOKUP_NO_TEMP_BIND for ref-qualifier handling.
diff --git a/gcc/cp/call.c b/gcc/cp/call.c
index 2c3d4ac..fc65b97 100644
--- a/gcc/cp/call.c
+++ b/gcc/cp/call.c
@@ -1999,6 +1999,9 @@ add_function_candidate (struct z_candidate **candidates,
object parameter has reference type. */
bool rv = FUNCTION_RVALUE_QUALIFIED (TREE_TYPE (fn));
parmtype = cp_build_reference_type (parmtype, rv);
+ /* Don't bind an rvalue to a const lvalue ref-qualifier. */
+ if (!rv)
+ lflags |= LOOKUP_NO_RVAL_BIND|LOOKUP_NO_TEMP_BIND;
}
else
{
diff --git a/gcc/testsuite/g++.dg/cpp0x/ref-qual15.C b/gcc/testsuite/g++.dg/cpp0x/ref-qual15.C
new file mode 100644
index 0000000..ca333c2
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/ref-qual15.C
@@ -0,0 +1,13 @@
+// PR c++/59296
+// { dg-do compile { target c++11 } }
+
+struct Type
+{
+ void get() const& { }
+ void get() const&& { }
+};
+
+int main()
+{
+ Type{}.get();
+}
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: C++ PATCH for c++/59296 (rvalue object and lvalue ref-qualifier)
2014-06-18 22:12 C++ PATCH for c++/59296 (rvalue object and lvalue ref-qualifier) Jason Merrill
2014-06-19 9:32 ` Jason Merrill
@ 2014-06-19 11:29 ` Marc Glisse
2014-06-20 13:12 ` Jason Merrill
1 sibling, 1 reply; 5+ messages in thread
From: Marc Glisse @ 2014-06-19 11:29 UTC (permalink / raw)
To: Jason Merrill; +Cc: gcc-patches List
On Thu, 19 Jun 2014, Jason Merrill wrote:
> We were treating a const & member function like a normal const reference, and
> binding an rvalue object argument to it. But it doesn't work that way.
That looks weird to me. The const&& version is a better match than the
const&, so we should pick that one in overload resolution, but if we
remove the const&& version, the other one seems valid to me, we shouldn't
reject this program:
struct Type
{
void get() const& { }
};
int main()
{
Type{}.get();
}
At least both clang and intel accept it, and I hope the standard didn't
make it behave differently from regular function calls.
--
Marc Glisse
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: C++ PATCH for c++/59296 (rvalue object and lvalue ref-qualifier)
2014-06-19 11:29 ` Marc Glisse
@ 2014-06-20 13:12 ` Jason Merrill
2014-06-20 18:28 ` Jason Merrill
0 siblings, 1 reply; 5+ messages in thread
From: Jason Merrill @ 2014-06-20 13:12 UTC (permalink / raw)
To: Marc Glisse; +Cc: gcc-patches List
On 06/19/2014 01:29 PM, Marc Glisse wrote:
> That looks weird to me. The const&& version is a better match than the
> const&, so we should pick that one in overload resolution, but if we
> remove the const&& version, the other one seems valid to me
Hmm, you're right, I was confused.
Jason
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: C++ PATCH for c++/59296 (rvalue object and lvalue ref-qualifier)
2014-06-20 13:12 ` Jason Merrill
@ 2014-06-20 18:28 ` Jason Merrill
0 siblings, 0 replies; 5+ messages in thread
From: Jason Merrill @ 2014-06-20 18:28 UTC (permalink / raw)
To: Marc Glisse; +Cc: gcc-patches List
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On 06/20/2014 03:11 PM, Jason Merrill wrote:
> On 06/19/2014 01:29 PM, Marc Glisse wrote:
>> That looks weird to me. The const&& version is a better match than the
>> const&, so we should pick that one in overload resolution, but if we
>> remove the const&& version, the other one seems valid to me
>
> Hmm, you're right, I was confused.
Here's a patch that fixes this properly.
Tested x86_64-pc-linux-gnu, applying to trunk.
[-- Attachment #2: 59296-3.patch --]
[-- Type: text/x-patch, Size: 1805 bytes --]
commit cc1e903c60c452ad7b618f6a9ff25ae85741424e
Author: Jason Merrill <jason@redhat.com>
Date: Fri Jun 20 14:51:21 2014 +0200
PR c++/59296
* call.c (add_function_candidate): Avoid special 'this' handling
if we have a ref-qualifier.
diff --git a/gcc/cp/call.c b/gcc/cp/call.c
index da91433..4847c3a 100644
--- a/gcc/cp/call.c
+++ b/gcc/cp/call.c
@@ -2025,9 +2025,9 @@ add_function_candidate (struct z_candidate **candidates,
object parameter has reference type. */
bool rv = FUNCTION_RVALUE_QUALIFIED (TREE_TYPE (fn));
parmtype = cp_build_reference_type (parmtype, rv);
- /* Don't bind an rvalue to a const lvalue ref-qualifier. */
- if (!rv)
- lflags |= LOOKUP_NO_RVAL_BIND|LOOKUP_NO_TEMP_BIND;
+ /* The special handling of 'this' conversions in compare_ics
+ does not apply if there is a ref-qualifier. */
+ is_this = false;
}
else
{
@@ -8597,10 +8597,11 @@ compare_ics (conversion *ics1, conversion *ics2)
/* [over.ics.rank]
--S1 and S2 are reference bindings (_dcl.init.ref_) and neither refers
- to an implicit object parameter, and either S1 binds an lvalue reference
- to an lvalue and S2 binds an rvalue reference or S1 binds an rvalue
- reference to an rvalue and S2 binds an lvalue reference
- (C++0x draft standard, 13.3.3.2)
+ to an implicit object parameter of a non-static member function
+ declared without a ref-qualifier, and either S1 binds an lvalue
+ reference to an lvalue and S2 binds an rvalue reference or S1 binds an
+ rvalue reference to an rvalue and S2 binds an lvalue reference (C++0x
+ draft standard, 13.3.3.2)
--S1 and S2 are reference bindings (_dcl.init.ref_), and the
types to which the references refer are the same type except for
^ permalink raw reply [flat|nested] 5+ messages in thread
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2014-06-18 22:12 C++ PATCH for c++/59296 (rvalue object and lvalue ref-qualifier) Jason Merrill
2014-06-19 9:32 ` Jason Merrill
2014-06-19 11:29 ` Marc Glisse
2014-06-20 13:12 ` Jason Merrill
2014-06-20 18:28 ` Jason Merrill
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