Hi!
cgraph_node has a semantic_interposition flag which should mirror
opt_for_fn (decl, flag_semantic_interposition). But it actually is
initialized not from that, but from flag_semantic_interposition in the
explicit symtab_node (symtab_type t)
: type (t), resolution (LDPR_UNKNOWN), definition (false), alias (false),
...
semantic_interposition (flag_semantic_interposition),
...
x_comdat_group (NULL_TREE), x_section (NULL)
{}
ctor. I think that might be fine for varpool nodes, but since
flag_semantic_interposition is now implied from -Ofast it isn't correct
for cgraph nodes, unless we guarantee that cgraph node for a particular
function decl is always created while that function is
current_function_decl. That is often the case, but not always as the
following function shows.
Because symtab_node's ctor doesn't know for which decl the cgraph node
is being created, the following patch keeps that as is, but updates it from
opt_for_fn (decl, flag_semantic_interposition) when we know that, or for
clones copies that flag (often it is then overridden in
set_new_clone_decl_and_node_flags, but not always).
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2022-04-20 Jakub Jelinek <ja...@redhat.com>
PR ipa/105306
* cgraph.cc (cgraph_node::create): Set node->semantic_interposition
to opt_for_fn (decl, flag_semantic_interposition).
* cgraphclones.cc (cgraph_node::create_clone): Copy over
semantic_interposition flag.
* g++.dg/opt/pr105306.C: New test.
--- gcc/cgraph.cc.jj 2022-02-04 14:36:54.069618372 +0100
+++ gcc/cgraph.cc 2022-04-19 13:38:06.223782974 +0200
@@ -507,6 +507,7 @@ cgraph_node::create (tree decl)
gcc_assert (TREE_CODE (decl) == FUNCTION_DECL);
node->decl = decl;
+ node->semantic_interposition = opt_for_fn (decl,
flag_semantic_interposition);
if ((flag_openacc || flag_openmp)
&& lookup_attribute ("omp declare target", DECL_ATTRIBUTES (decl)))
--- gcc/cgraphclones.cc.jj 2022-01-18 11:58:58.948991114 +0100
+++ gcc/cgraphclones.cc 2022-04-19 13:38:43.594262397 +0200
@@ -394,6 +394,7 @@ cgraph_node::create_clone (tree new_decl
new_node->versionable = versionable;
new_node->can_change_signature = can_change_signature;
new_node->redefined_extern_inline = redefined_extern_inline;
+ new_node->semantic_interposition = semantic_interposition;
new_node->tm_may_enter_irr = tm_may_enter_irr;
new_node->externally_visible = false;
new_node->no_reorder = no_reorder;
--- gcc/testsuite/g++.dg/opt/pr105306.C.jj 2022-04-19 13:42:33.908054114
+0200
+++ gcc/testsuite/g++.dg/opt/pr105306.C 2022-04-19 13:42:08.859403045 +0200
@@ -0,0 +1,13 @@
+// PR ipa/105306
+// { dg-do compile }
+// { dg-options "-Ofast" }
+
+#pragma GCC optimize 0
+template <typename T> void foo (T);
+struct B { ~B () {} };
+struct C { B f; };
+template <typename> struct E {
+ void bar () { foo (g); }
+ C g;
+};
+template class E<char>;
Jakub
