[PATCH] cgraph: Don't verify semantic_interposition flag for aliases [PR105399]

[Jakub Jelinek <jakub@redhat.com>]

Hi!

The following testcase ICEs, because the ctors during cc1plus all have
!opt_for_fn (decl, flag_semantic_interposition) - they have NULL
DECL_FUNCTION_SPECIFIC_OPTIMIZATION (decl) and optimization_default_node
is for -Ofast and so has flag_semantic_interposition cleared.
During free lang data, we set DECL_FUNCTION_SPECIFIC_OPTIMIZATION (decl)
for the ctor which has body (or for thunks), but don't touch it for
aliases.
During lto1 optimization_default_node reflects the lto1 flags which
are -O2 rather than -Ofast and so has flag_semantic_interposition
set, for the ctor which has body that makes no difference, but as the
alias doesn't still have DECL_FUNCTION_SPECIFIC_OPTIMIZATION (decl) set,
we now trigger this verification check.

The following patch just doesn't verify it for aliases during lto1.
Another possibility would be to set DECL_FUNCTION_SPECIFIC_OPTIMIZATION (decl)
during free lang data even for aliases.

Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

2022-04-28  Jakub Jelinek  <jakub@redhat.com>

	PR lto/105399
	* cgraph.cc (cgraph_node::verify_node): Don't verify
	semantic_interposition flag against
	opt_for_fn (decl, flag_semantic_interposition) for aliases in lto1.

	* g++.dg/lto/pr105399_0.C: New test.

--- gcc/cgraph.cc.jj	2022-04-20 09:24:12.194579146 +0200
+++ gcc/cgraph.cc	2022-04-27 11:53:52.102173154 +0200
@@ -3488,7 +3488,9 @@ cgraph_node::verify_node (void)
 	     "returns a pointer");
       error_found = true;
     }
-  if (definition && externally_visible
+  if (definition
+      && externally_visible
+      && (!alias || thunk || !in_lto_p)
       && semantic_interposition
 	 != opt_for_fn (decl, flag_semantic_interposition))
     {
--- gcc/testsuite/g++.dg/lto/pr105399_0.C.jj	2022-04-27 11:54:25.659703199 +0200
+++ gcc/testsuite/g++.dg/lto/pr105399_0.C	2022-04-27 11:48:31.387664565 +0200
@@ -0,0 +1,9 @@
+// PR lto/105399
+// { dg-lto-do link }
+// { dg-lto-options { { -fPIC -flto -Ofast } } }
+// { dg-require-effective-target shared }
+// { dg-require-effective-target fpic }
+// { dg-extra-ld-options "-shared -O2" }
+
+struct S { S (); };
+S::S () {}

	Jakub