summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorPatrick Palka <ppalka@redhat.com>2022-01-24 09:17:35 -0500
committerPatrick Palka <ppalka@redhat.com>2022-01-24 09:17:35 -0500
commit2a908f3da07c9e94b8a19e966b45daf0140107e8 (patch)
tree40d0d91058738beeae31277f037abac21b4618c3
parent978abe918f8c8deed28e92297d3c0cc39086ad83 (diff)
c++: value category of compound object expr [PR104173]
Here the call to (the &&-qualified) toLower() is incorrectly rejected during overload resolution because the object expression is encoded as an lvalue when it's really a prvalue. The object expression, instance()->applicationName(), is encoded as an INDIRECT_REF of a COMPOUND_EXPR *(*instance ();, &TARGET_EXPR <D.2383, QCoreApplication::applicationName ()>;); which lvalue_kind deems an lvalue. This issue is similar to PR88103 except that here the original 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 xvalueness of the original expression is preserved. This patch extends that fix so that rvalueness is preserved more generally. 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.
-rw-r--r--gcc/cp/typeck.cc19
-rw-r--r--gcc/testsuite/g++.dg/cpp0x/ref-qual21.C23
2 files changed, 31 insertions, 11 deletions
diff --git a/gcc/cp/typeck.cc b/gcc/cp/typeck.cc
index 3a28d639cb1..11c9d8aff3e 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 rvalueness. */
+ 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..7f867c21706
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/ref-qual21.C
@@ -0,0 +1,23 @@
+// PR c++/104173
+// { dg-do compile { target c++11 } }
+
+struct QString {
+ QString toLower() &&;
+};
+
+struct QCoreApplication {
+ static QString applicationName();
+};
+
+QCoreApplication* instance();
+
+void f() {
+ instance()->applicationName().toLower();
+}
+
+template<class...>
+void g() {
+ instance()->applicationName().toLower();
+}
+
+template void g<>();