* [pushed] c++: aggregate base and TARGET_EXPR_ELIDING_P [PR108559]
@ 2023-02-01 0:11 Jason Merrill
0 siblings, 0 replies; only message in thread
From: Jason Merrill @ 2023-02-01 0:11 UTC (permalink / raw)
To: gcc-patches
Tested x86_64-pc-linux-gnu, applying to trunk.
-- 8< --
We also need to split up a CONSTRUCTOR in cp_genericize_init if we need to
add extra copy constructor calls to deal with CWG2403.
PR c++/108559
gcc/cp/ChangeLog:
* cp-gimplify.cc (any_non_eliding_target_exprs): New.
(cp_genericize_init): Check it.
gcc/testsuite/ChangeLog:
* g++.dg/cpp1z/aggr-base13.C: New test.
---
gcc/cp/cp-gimplify.cc | 22 +++++++++++++++++++---
gcc/testsuite/g++.dg/cpp1z/aggr-base13.C | 19 +++++++++++++++++++
2 files changed, 38 insertions(+), 3 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/cpp1z/aggr-base13.C
diff --git a/gcc/cp/cp-gimplify.cc b/gcc/cp/cp-gimplify.cc
index a35cedd05cc..9929d29981a 100644
--- a/gcc/cp/cp-gimplify.cc
+++ b/gcc/cp/cp-gimplify.cc
@@ -893,6 +893,21 @@ omp_cxx_notice_variable (struct cp_genericize_omp_taskreg *omp_ctx, tree decl)
}
}
+/* True if any of the element initializers in CTOR are TARGET_EXPRs that are
+ not expected to elide, e.g. because unsafe_copy_elision_p is true. */
+
+static bool
+any_non_eliding_target_exprs (tree ctor)
+{
+ for (const constructor_elt &e : *CONSTRUCTOR_ELTS (ctor))
+ {
+ if (TREE_CODE (e.value) == TARGET_EXPR
+ && !TARGET_EXPR_ELIDING_P (e.value))
+ return true;
+ }
+ return false;
+}
+
/* If we might need to clean up a partially constructed object, break down the
CONSTRUCTOR with split_nonconstant_init. Also expand VEC_INIT_EXPR at this
point. If initializing TO with FROM is non-trivial, overwrite *REPLACE with
@@ -904,10 +919,11 @@ cp_genericize_init (tree *replace, tree from, tree to)
tree init = NULL_TREE;
if (TREE_CODE (from) == VEC_INIT_EXPR)
init = expand_vec_init_expr (to, from, tf_warning_or_error);
- else if (flag_exceptions
- && TREE_CODE (from) == CONSTRUCTOR
+ else if (TREE_CODE (from) == CONSTRUCTOR
&& TREE_SIDE_EFFECTS (from)
- && TYPE_HAS_NONTRIVIAL_DESTRUCTOR (TREE_TYPE (from)))
+ && ((flag_exceptions
+ && TYPE_HAS_NONTRIVIAL_DESTRUCTOR (TREE_TYPE (from)))
+ || any_non_eliding_target_exprs (from)))
{
to = cp_stabilize_reference (to);
replace_placeholders (from, to);
diff --git a/gcc/testsuite/g++.dg/cpp1z/aggr-base13.C b/gcc/testsuite/g++.dg/cpp1z/aggr-base13.C
new file mode 100644
index 00000000000..c4c7ee0e8f0
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1z/aggr-base13.C
@@ -0,0 +1,19 @@
+// PR c++/108559
+// { dg-do compile { target c++17 } }
+
+struct A {
+ int g = 0;
+
+ A() {}
+ A(const A&) {}
+};
+
+struct B : A {};
+
+A u() { return A{}; }
+
+int bug() { return B{u()}.g; }
+
+int main() {
+ return 0;
+}
base-commit: a9fbc6687faa09bf045c0fcee7960b7fef796fcc
--
2.31.1
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