On 7/22/21 7:15 PM, Sergei Trofimovich wrote:
From: Sergei Trofimovich <siarh...@google.com>
r12-1804 ("cp: add support for per-location warning groups.") among other
things removed warning suppression from a few places including ptrmemfuncs.
Currently ptrmemfuncs don't have valid BINFO attached which causes ICEs
in access checks:
crash_signal
gcc/toplev.c:328
perform_or_defer_access_check(tree_node*, tree_node*, tree_node*, int,
access_failure_info*)
gcc/cp/semantics.c:490
finish_non_static_data_member(tree_node*, tree_node*, tree_node*)
gcc/cp/semantics.c:2208
...
The change suppresses warnings again until we provide BINFOs for ptrmemfuncs.
We don't need BINFOs for PMFs, we need to avoid paths that expect them.
It looks like the problem is with tsubst_copy_and_build calling
finish_non_static_data_member instead of build_ptrmemfunc_access_expr.
PR c++/101219
gcc/cp/ChangeLog:
* typeck.c (build_ptrmemfunc_access_expr): Suppress all warnings
to avoid ICE.
gcc/testsuite/ChangeLog:
* g++.dg/torture/pr101219.C: New test.
This doesn't need to be in torture; it has nothing to do with optimization.
---
gcc/cp/typeck.c | 6 +++++-
gcc/testsuite/g++.dg/torture/pr101219.C | 10 ++++++++++
2 files changed, 15 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/g++.dg/torture/pr101219.C
diff --git a/gcc/cp/typeck.c b/gcc/cp/typeck.c
index a483e1f988d..aa91fd21c7b 100644
--- a/gcc/cp/typeck.c
+++ b/gcc/cp/typeck.c
@@ -3326,7 +3326,11 @@ build_ptrmemfunc_access_expr (tree ptrmem, tree
member_name)
member = DECL_CHAIN (member))
if (DECL_NAME (member) == member_name)
break;
- return build_simple_component_ref (ptrmem, member);
+ tree r = build_simple_component_ref (ptrmem, member);
+ /* Suppress warning to avoid exposing missing BINFO for ptrmem
+ synthetic structs: PR101219. */
+ suppress_warning(r);
+ return r;
}
/* Given an expression PTR for a pointer, return an expression
diff --git a/gcc/testsuite/g++.dg/torture/pr101219.C
b/gcc/testsuite/g++.dg/torture/pr101219.C
new file mode 100644
index 00000000000..c8d30448187
--- /dev/null
+++ b/gcc/testsuite/g++.dg/torture/pr101219.C
@@ -0,0 +1,10 @@
+/* { dg-do compile } */
+/* { dg-additional-options "-Wall" } */
+struct S { void m(); };
+
+template <int> bool f() {
+ /* In PR101219 gcc used to ICE in warning code. */
+ void (S::*mp)();
+
+ return &S::m == mp;
+}
