On Wed, 14 Dec 2011, Richard Guenther wrote:
>
> The following patch avoids streaming extern var and function decls
> into the global decls and types section when streaming a tree
> chain list (effectively only when processing BLOCK_VARS). This
> avoids the last LTO debug-info ICE I know of (knocks on wood)
> and provides a cleaner (well ...) fix for PR48437 as well.
>
> LTO bootstrapped on x86_64-unknown-linux-gnu, testing in progress,
> so is SPEC 2k6 build with -g (hopefully now without ICEs as well).
Incrementally better. Reducing a different remaining ICE on
483.xalancbmk right now. At least we'll get some more testcases.
> I plan to commit this tomorrow if all goes well and declare
> LTO debug-info perfect for 4.7.
Done, but not perfect yet ;)
Richard.
> 2011-12-14 Richard Guenther <rguent...@suse.de>
>
> Revert
> PR lto/48437
> * lto-streamer-out.c (tree_is_indexable): Exclude block-local
> extern declarations.
>
> PR lto/48508
> PR lto/48437
> * tree-streamer-out.c (streamer_write_chain): Stream DECL_EXTERNAL
> VAR_DECLs and FUNCTION_DECLs locally.
>
> * g++.dg/lto/pr48508-1_0.C: New testcase.
> * g++.dg/lto/pr48508-1_1.C: Likewise.
>
> Index: gcc/lto-streamer-out.c
> ===================================================================
> *** gcc/lto-streamer-out.c (revision 182335)
> --- gcc/lto-streamer-out.c (working copy)
> *************** tree_is_indexable (tree t)
> *** 129,144 ****
> else if (TREE_CODE (t) == VAR_DECL && decl_function_context (t)
> && !TREE_STATIC (t))
> return false;
> - /* If this is a decl generated for block local externs for
> - debug info generation, stream it unshared alongside BLOCK_VARS. */
> - else if (VAR_OR_FUNCTION_DECL_P (t)
> - /* ??? The following tests are a literal match on what
> - c-decl.c:pop_scope does. */
> - && TREE_PUBLIC (t)
> - && DECL_EXTERNAL (t)
> - && DECL_CONTEXT (t)
> - && TREE_CODE (DECL_CONTEXT (t)) == FUNCTION_DECL)
> - return false;
> /* Variably modified types need to be streamed alongside function
> bodies because they can refer to local entities. Together with
> them we have to localize their members as well.
> --- 129,134 ----
> Index: gcc/tree-streamer-out.c
> ===================================================================
> *** gcc/tree-streamer-out.c (revision 182335)
> --- gcc/tree-streamer-out.c (working copy)
> *************** streamer_write_chain (struct output_bloc
> *** 405,411 ****
> saved_chain = TREE_CHAIN (t);
> TREE_CHAIN (t) = NULL_TREE;
>
> ! stream_write_tree (ob, t, ref_p);
>
> TREE_CHAIN (t) = saved_chain;
> t = TREE_CHAIN (t);
> --- 405,417 ----
> saved_chain = TREE_CHAIN (t);
> TREE_CHAIN (t) = NULL_TREE;
>
> ! /* We avoid outputting external vars or functions by reference
> ! to the global decls section as we do not want to have them
> ! enter decl merging. This is, of course, only for the call
> ! for streaming BLOCK_VARS, but other callers are safe. */
> ! stream_write_tree (ob, t,
> ! ref_p && !(VAR_OR_FUNCTION_DECL_P (t)
> ! && DECL_EXTERNAL (t)));
>
> TREE_CHAIN (t) = saved_chain;
> t = TREE_CHAIN (t);
> Index: gcc/testsuite/g++.dg/lto/pr48508-1_0.C
> ===================================================================
> *** gcc/testsuite/g++.dg/lto/pr48508-1_0.C (revision 0)
> --- gcc/testsuite/g++.dg/lto/pr48508-1_0.C (revision 0)
> ***************
> *** 0 ****
> --- 1,7 ----
> + // { dg-lto-do link }
> + // { dg-lto-options { { -g -O2 -flto -flto-partition=none } } }
> +
> + void __attribute__((externally_visible))
> + foo (int i)
> + {
> + }
> Index: gcc/testsuite/g++.dg/lto/pr48508-1_1.C
> ===================================================================
> *** gcc/testsuite/g++.dg/lto/pr48508-1_1.C (revision 0)
> --- gcc/testsuite/g++.dg/lto/pr48508-1_1.C (revision 0)
> ***************
> *** 0 ****
> --- 1,10 ----
> + static void
> + bar (void)
> + {
> + extern void foo (int);
> + foo (0);
> + }
> + int main()
> + {
> + bar ();
> + }
>
--
Richard Guenther <rguent...@suse.de>
SUSE / SUSE Labs
SUSE LINUX Products GmbH - Nuernberg - AG Nuernberg - HRB 16746
GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer
