From 29e4163a092ce08ba3a88a05ac2fa3f23b1cec28 Mon Sep 17 00:00:00 2001
From: Jason Merrill <jason@redhat.com>
Date: Mon, 15 Nov 2021 12:59:08 -0500
Subject: [PATCH] c++: split_nonconstant_init and flexarrays
split_nonconstant_init was doing the wrong thing for both the initialization
and cleanup here; we know the size from the initializer, and we can pass it
along. This doesn't make the testcase work, since the y destructor is still
broken, but it removes the wrong error for the aggregate initialization.
gcc/cp/ChangeLog:
* typeck2.c (split_nonconstant_init_1): Handle flexarrays better.
gcc/testsuite/ChangeLog:
* g++.dg/ext/flexary37.C: Remove expected error.
---
gcc/cp/typeck2.c | 9 +++++++++
gcc/testsuite/g++.dg/ext/flexary37.C | 2 +-
2 files changed, 10 insertions(+), 1 deletion(-)
diff --git a/gcc/cp/typeck2.c b/gcc/cp/typeck2.c
index c01f2f8ced44..e98fbf7f5fa3 100644
--- a/gcc/cp/typeck2.c
+++ b/gcc/cp/typeck2.c
@@ -484,6 +484,15 @@ split_nonconstant_init_1 (tree dest, tree init, bool nested)
&& TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
|| vla_type_p (type))
{
+ if (!TYPE_DOMAIN (type)
+ && TREE_CODE (init) == CONSTRUCTOR
+ && CONSTRUCTOR_NELTS (init))
+ {
+ /* Flexible array. */
+ cp_complete_array_type (&type, init, /*default*/true);
+ dest = build1 (VIEW_CONVERT_EXPR, type, dest);
+ }
+
/* For an array, we only need/want a single cleanup region rather
than one per element. */
tree code = build_vec_init (dest, NULL_TREE, init, false, 1,
diff --git a/gcc/testsuite/g++.dg/ext/flexary37.C b/gcc/testsuite/g++.dg/ext/flexary37.C
index ceb5053de2e1..5cd48c1f773f 100644
--- a/gcc/testsuite/g++.dg/ext/flexary37.C
+++ b/gcc/testsuite/g++.dg/ext/flexary37.C
@@ -12,4 +12,4 @@ public:
struct y { // { dg-error "unknown array size in delete" }
int a; C b[];
-} y = { 1, { { 2, 3 } } }; // { dg-error "unknown array size in delete" }
+} y = { 1, { { 2, 3 } } };
--
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