From dbb17a22383faa7837bdd2ea9c902bfab53fa8f2 Mon Sep 17 00:00:00 2001 From: Sergei Trofimovich Date: Fri, 6 Aug 2021 16:14:16 +0100 Subject: [PATCH v3] c++: fix ptrmemfunc template instantiation [PR101219] r12-1804 ("cp: add support for per-location warning groups.") among other things removed warning suppression from a few places including ptrmemfuncs. This exposed a bug in warning detection code as a reference to missing BINFO (it's intentionally missing for ptrmemfunc types): 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 special cases ptrmemfuncs in templace substitution by using build_ptrmemfunc_access_expr() instead of finish_non_static_data_member(). PR c++/101219 gcc/cp/ChangeLog: * pt.c (tsubst_copy_and_build): Use build_ptrmemfunc_access_expr to construct ptrmemfunc expression instantiation. gcc/testsuite/ChangeLog: * g++.dg/warn/pr101219.C: New test. --- Change since v2: fix whitespace around macros. gcc/cp/pt.c | 8 +++++++- gcc/testsuite/g++.dg/warn/pr101219.C | 11 +++++++++++ 2 files changed, 18 insertions(+), 1 deletion(-) create mode 100644 gcc/testsuite/g++.dg/warn/pr101219.C diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c index b396ddd0089..42ea51cebc0 100644 --- a/gcc/cp/pt.c +++ b/gcc/cp/pt.c @@ -20530,7 +20530,13 @@ tsubst_copy_and_build (tree t, if (member == error_mark_node) RETURN (error_mark_node); - if (TREE_CODE (member) == FIELD_DECL) + if (object_type && TYPE_PTRMEMFUNC_P (object_type) + && TREE_CODE (member) == FIELD_DECL) + { + r = build_ptrmemfunc_access_expr (object, DECL_NAME (member)); + RETURN (r); + } + else if (TREE_CODE (member) == FIELD_DECL) { r = finish_non_static_data_member (member, object, NULL_TREE); if (TREE_CODE (r) == COMPONENT_REF) diff --git a/gcc/testsuite/g++.dg/warn/pr101219.C b/gcc/testsuite/g++.dg/warn/pr101219.C new file mode 100644 index 00000000000..0d23d73c9ec --- /dev/null +++ b/gcc/testsuite/g++.dg/warn/pr101219.C @@ -0,0 +1,11 @@ +/* PR c++/101219 - ICE on use of uninitialized memfun pointer + { dg-do compile } + { dg-options "-Wall" } */ + +struct S { void m(); }; + +template bool f() { + void (S::*mp)(); + + return &S::m == mp; // no warning emitted here (no instantiation) +} -- 2.32.0