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).
I plan to commit this tomorrow if all goes well and declare
LTO debug-info perfect for 4.7.
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 ();
+ }
