>
> Currently a _lot_ of packages fail to build with LTO because LTO
> messes up fortify wrappers by replacing the call to the alias with
> the symbol itself, making the wrapper look like infinitely
> recursing.
>
> The following patch fixes this by dropping the bodies of
> DECL_EXTERN always-inline functions on the floor before IPA
> (and when doing LTO). IMHO we should at some point do this
> unconditional on LTO as the early inliner is supposed to
> remove all references to always-inline functions.
>
> I'm not 100% sure about the cgraph API use to drop the function
> body, but at least it seems to work ;) I'm not sure if we want
> to restrict the set of functions to apply this even more than
> just those with always-inline and DECL_EXTERNAL set?
>
> Now double-checking with a fortified LTO bootstrap.
>
> Ok for trunk?
>
> Thanks,
> Richard.
>
> 2014-03-24 Richard Biener <rguent...@suse.de>
>
> PR lto/59626
> * passes.c (ipa_write_summaries): Drop function bodies of
> extern always-inline functions.
>
> * gcc.dg/lto/pr59626_0.c: New testcase.
> * gcc.dg/lto/pr59626_1.c: Likewise.
>
Hi,
do you see some problem with this approach? Unlike in dropping for
ipa_write_summaries
it drops just after early optimizations and it is done unconditonally.
I see it kills every cross module inlining of extern inlines, but so does your
patch.
This may make difference for C++ implicit extern inlines (keyed functions)
where I can
imagine users both to declare them always inline and then call indirectly...
I do it unconditionally because I do not like much of idea of making the LTO
and non-LTO
pipelines diverging even more.
Honza
Index: ipa.c
===================================================================
--- ipa.c (revision 208798)
+++ ipa.c (working copy)
@@ -139,7 +139,10 @@ process_references (struct ipa_ref_list
if (node->definition && !node->in_other_partition
&& ((!DECL_EXTERNAL (node->decl) || node->alias)
- || (before_inlining_p
+ || (((before_inlining_p
+ && (cgraph_state < CGRAPH_STATE_IPA_SSA
+ || !lookup_attribute ("always_inline",
+ DECL_ATTRIBUTES (node->decl)))))
/* We use variable constructors during late complation for
constant folding. Keep references alive so partitioning
knows about potential references. */
@@ -191,7 +194,10 @@ walk_polymorphic_call_targets (pointer_s
/* Prior inlining, keep alive bodies of possible targets for
devirtualization. */
if (n->definition
- && before_inlining_p)
+ && (before_inlining_p
+ && (cgraph_state < CGRAPH_STATE_IPA_SSA
+ || !lookup_attribute ("always_inline",
+ DECL_ATTRIBUTES (n->decl)))))
pointer_set_insert (reachable, n);
/* Even after inlining we want to keep the possible targets in the
