On 3/25/25 3:37 PM, Marek Polacek wrote:
Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk/14?
-- >8 --
Since r15-8011 cp_build_indirect_ref_1 won't do the *&TARGET_EXPR ->
TARGET_EXPR folding not to change its value category. That fix is
correct but it made us stop extending the lifetime in this testcase,
causing a wrong-code issue -- extend_ref_init_temps_1 did not see
through the extra *& because it doesn't use a tree walk. It is not
hard to fix that, but there may be other places that need this
adjustment. :/
Hmm, this suggests to me that we should revert the 117512 patch and
instead fix it in build_over_call, perhaps by forcing 'val' to be an
lvalue after it's built rather than relying on 'to' being an lvalue already.
PR c++/119383
gcc/cp/ChangeLog:
* call.cc (extend_ref_init_temps_1): Handle *&TARGET_EXPR the same as
TARGET_EXPR.
gcc/testsuite/ChangeLog:
* g++.dg/cpp0x/temp-extend3.C: New test.
---
gcc/cp/call.cc | 6 +++++
gcc/testsuite/g++.dg/cpp0x/temp-extend3.C | 32 +++++++++++++++++++++++
2 files changed, 38 insertions(+)
create mode 100644 gcc/testsuite/g++.dg/cpp0x/temp-extend3.C
diff --git a/gcc/cp/call.cc b/gcc/cp/call.cc
index c1c8987ec8b..ed2bdc85d87 100644
--- a/gcc/cp/call.cc
+++ b/gcc/cp/call.cc
@@ -14835,6 +14835,12 @@ extend_ref_init_temps_1 (tree decl, tree init, vec<tree,
va_gc> **cleanups,
for (p = &TREE_OPERAND (sub, 0);
TREE_CODE (*p) == COMPONENT_REF || TREE_CODE (*p) == ARRAY_REF; )
p = &TREE_OPERAND (*p, 0);
+ /* cp_build_indirect_ref_1 leaves *&TARGET_EXPR intact, handle it here. */
+ if (INDIRECT_REF_P (*p)
+ && TREE_CODE (TREE_OPERAND (*p, 0)) == ADDR_EXPR
+ && same_type_p (TREE_TYPE (*p),
+ TREE_TYPE (TREE_TYPE (TREE_OPERAND (*p, 0)))))
+ p = &TREE_OPERAND (TREE_OPERAND (*p, 0), 0);
if (TREE_CODE (*p) == TARGET_EXPR)
{
tree subinit = NULL_TREE;
diff --git a/gcc/testsuite/g++.dg/cpp0x/temp-extend3.C
b/gcc/testsuite/g++.dg/cpp0x/temp-extend3.C
new file mode 100644
index 00000000000..3eab88d0076
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/temp-extend3.C
@@ -0,0 +1,32 @@
+// PR c++/119383
+// { dg-do run { target c++11 } }
+
+int g;
+
+struct base {
+ virtual base *clone() const = 0;
+ ~base() { }
+};
+
+struct impl : virtual base {
+ base *clone() const { return new impl; } // #1
+ impl() { ++g; }
+ ~impl() { --g; }
+};
+
+const base *
+make_a_clone ()
+{
+ const base &base = impl{}; // #2
+ return base.clone();
+}
+
+int
+main ()
+{
+ make_a_clone ();
+ // impl::impl() is called twice (#1 and #2), impl::~impl() once,
+ // at the end of make_a_clone.
+ if (g != 1)
+ __builtin_abort ();
+}
base-commit: 927cfea902c330092848bd7a228b714b07d08f6b
