Hi!
My FE change from 2 years ago uses TREE_ASM_WRITTEN in -fsyntax-only
mode more aggressively to avoid "expanding" functions multiple times.
With -fsyntax-only nothing is really expanded, so I think it is acceptable
to adjust the assert and allow declare_weak at any time, with -fsyntax-only
we know it is during parsing only anyway.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2021-02-10 Jakub Jelinek <ja...@redhat.com>
PR c++/99035
* varasm.c (declare_weak): For -fsyntax-only, allow even
TREE_ASM_WRITTEN function decls.
* g++.dg/ext/weak6.C: New test.
--- gcc/varasm.c.jj 2021-01-04 10:25:38.824233926 +0100
+++ gcc/varasm.c 2021-02-10 13:18:29.278890110 +0100
@@ -5927,7 +5927,9 @@ merge_weak (tree newdecl, tree olddecl)
void
declare_weak (tree decl)
{
- gcc_assert (TREE_CODE (decl) != FUNCTION_DECL || !TREE_ASM_WRITTEN (decl));
+ gcc_assert (TREE_CODE (decl) != FUNCTION_DECL
+ || !TREE_ASM_WRITTEN (decl)
+ || flag_syntax_only);
if (! TREE_PUBLIC (decl))
{
error ("weak declaration of %q+D must be public", decl);
--- gcc/testsuite/g++.dg/ext/weak6.C.jj 2021-02-10 13:26:52.862203677 +0100
+++ gcc/testsuite/g++.dg/ext/weak6.C 2021-02-10 13:26:46.439276213 +0100
@@ -0,0 +1,8 @@
+// PR c++/99035
+// { dg-do compile }
+// { dg-require-weak "" }
+// { dg-options "-fsyntax-only" }
+
+extern void * foo (void);
+void * foo (void) { return (void *)foo; }
+#pragma weak foo
Jakub
