On 7/19/23 14:38, Marek Polacek wrote:
On Wed, Jul 19, 2023 at 02:32:15PM -0400, Patrick Palka wrote:
On Wed, 19 Jul 2023, Marek Polacek wrote:
Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk?
LGTM. It might be preferable to check COMPLETE_TYPE_P in the caller
instead, so that we avoid inspecting CLASSTYPE_NON_AGGREGATE on an
incomplete class type, and so that the caller doesn't "commit" to
building an aggregate conversion.
Perhaps. I wanted to avoid the call to build_user_type_conversion_1.
I could add an early return to implicit_conversion_1 but I'd have to
move some code around not to check COMPLETE_TYPE_P before complete_type.
Maybe return NULL for the incomplete case here, rather than just
skipping reshape_init?
/* Call reshape_init early to remove redundant braces. */
if (expr && BRACE_ENCLOSED_INITIALIZER_P (expr)
&& CLASS_TYPE_P (to)
&& COMPLETE_TYPE_P (complete_type (to))
&& !CLASSTYPE_NON_AGGREGATE (to))
{
expr = reshape_init (to, expr, complain);
if (expr == error_mark_node)
return NULL;
from = TREE_TYPE (expr);
}
If that doesn't work, the patch is fine as-is.
-- >8 --
r13-1227 added an assert checking that the index in a CONSTRUCTOR
is a FIELD_DECL. That's a reasonable assumption but in this case
we never called reshape_init due to the type being incomplete, and
so the index remained an identifier node: get_class_binding never
got around to looking up the FIELD_DECL.
We can avoid the crash by returning early in build_aggr_conv; we'd
return NULL anyway due to:
if (i < CONSTRUCTOR_NELTS (ctor))
return NULL;
PR c++/110114
gcc/cp/ChangeLog:
* call.cc (build_aggr_conv): Return early if the type isn't
complete.
gcc/testsuite/ChangeLog:
* g++.dg/cpp2a/desig28.C: New test.
* g++.dg/cpp2a/desig29.C: New test.
---
gcc/cp/call.cc | 5 +++++
gcc/testsuite/g++.dg/cpp2a/desig28.C | 17 +++++++++++++++++
gcc/testsuite/g++.dg/cpp2a/desig29.C | 10 ++++++++++
3 files changed, 32 insertions(+)
create mode 100644 gcc/testsuite/g++.dg/cpp2a/desig28.C
create mode 100644 gcc/testsuite/g++.dg/cpp2a/desig29.C
diff --git a/gcc/cp/call.cc b/gcc/cp/call.cc
index b55230d98aa..0af20a81717 100644
--- a/gcc/cp/call.cc
+++ b/gcc/cp/call.cc
@@ -986,6 +986,11 @@ build_aggr_conv (tree type, tree ctor, int flags,
tsubst_flags_t complain)
tree empty_ctor = NULL_TREE;
hash_set<tree, true> pset;
+ /* We've called complete_type on TYPE before calling this function, but
+ perhaps it wasn't successful. */
+ if (!COMPLETE_TYPE_P (type))
+ return nullptr;
+
/* We already called reshape_init in implicit_conversion, but it might not
have done anything in the case of parenthesized aggr init. */
diff --git a/gcc/testsuite/g++.dg/cpp2a/desig28.C b/gcc/testsuite/g++.dg/cpp2a/desig28.C
new file mode 100644
index 00000000000..b63265fea51
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp2a/desig28.C
@@ -0,0 +1,17 @@
+// PR c++/110114
+// { dg-do compile { target c++20 } }
+
+struct A {
+ int a,b;
+};
+
+struct B;
+
+void foo(const A &) {}
+void foo(const B &) {}
+
+int
+main ()
+{
+ foo({.a=0});
+}
diff --git a/gcc/testsuite/g++.dg/cpp2a/desig29.C
b/gcc/testsuite/g++.dg/cpp2a/desig29.C
new file mode 100644
index 00000000000..bd1a82b041d
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp2a/desig29.C
@@ -0,0 +1,10 @@
+// PR c++/110114
+// { dg-do compile { target c++20 } }
+
+struct B;
+
+void foo(const B &) {}
+
+int main() {
+ foo({.a=0}); // { dg-error "invalid" }
+}
base-commit: 2971ff7b1d564ac04b537d907c70e6093af70832
--
2.41.0
Marek
