Here the call to the &&-qualified toLower() is incorrectly rejected
because the object expression is deemed to be an lvalue, even though it's
really a prvalue. The object expression, instance()->applicationName(),
is expressed as an INDIRECT_REF of a COMPOUND_EXPR
*(*instance ();, &TARGET_EXPR <D.2383, QCoreApplication::applicationName
()>;);
which lvalue_kind categorizes as an lvalue.
This issue seems similar to PR88103 except that here the compound object
expression is a prvalue rather than an xvalue. The fix there was to
adjust the result of unary_complex_lvalue in build_class_member_access_expr
so that xvalue-ness is preserved. This patch extends the fix so that
rvalue-ness is preserved more generally.
Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for
trunk?
PR c++/104173
gcc/cp/ChangeLog:
* typeck.cc (build_class_member_access_expr): Extend
unary_complex_lvalue result adjustment to preserve all
rvalues, not just xvalues.
gcc/testsuite/ChangeLog:
* g++.dg/cpp0x/ref-qual21.C: New test.
---
gcc/cp/typeck.cc | 19 ++++++++-----------
gcc/testsuite/g++.dg/cpp0x/ref-qual21.C | 16 ++++++++++++++++
2 files changed, 24 insertions(+), 11 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/cpp0x/ref-qual21.C
diff --git a/gcc/cp/typeck.cc b/gcc/cp/typeck.cc
index 3a28d639cb1..59668203573 100644
--- a/gcc/cp/typeck.cc
+++ b/gcc/cp/typeck.cc
@@ -2726,17 +2726,14 @@ build_class_member_access_expr (cp_expr object, tree
member,
/* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x' into
`(*(a ? &b : &c)).x', and so on. A COND_EXPR is only an lvalue
in the front end; only _DECLs and _REFs are lvalues in the back end. */
- {
- tree temp = unary_complex_lvalue (ADDR_EXPR, object);
- if (temp)
- {
- temp = cp_build_fold_indirect_ref (temp);
- if (xvalue_p (object) && !xvalue_p (temp))
- /* Preserve xvalue kind. */
- temp = move (temp);
- object = temp;
- }
- }
+ if (tree temp = unary_complex_lvalue (ADDR_EXPR, object))
+ {
+ temp = cp_build_fold_indirect_ref (temp);
+ if (!lvalue_p (object) && lvalue_p (temp))
+ /* Preserve rvalue-ness. */
+ temp = move (temp);
+ object = temp;
+ }
/* In [expr.ref], there is an explicit list of the valid choices for
MEMBER. We check for each of those cases here. */
diff --git a/gcc/testsuite/g++.dg/cpp0x/ref-qual21.C
b/gcc/testsuite/g++.dg/cpp0x/ref-qual21.C
new file mode 100644
index 00000000000..e2c43c345ab
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/ref-qual21.C
@@ -0,0 +1,16 @@
+// PR c++/104173
+// { dg-do compile { target c++11 } }
+
+struct QString {
+ QString toLower() &&;
+};
+
+struct QCoreApplication {
+ static QString applicationName();
+};
+
+QCoreApplication *instance();
+
+int main() {
+ instance()->applicationName().toLower();
+}
--
2.35.0.rc1
