[Bug lto/55466] [4.8 Regression] Revision 191466 destroyed DWARF debug info
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55466 --- Comment #13 from hjl at gcc dot gnu.org hjl at gcc dot gnu.org 2013-01-03 16:54:07 UTC --- Author: hjl Date: Thu Jan 3 16:53:54 2013 New Revision: 194861 URL: http://gcc.gnu.org/viewcvs?root=gccview=revrev=194861 Log: Fix ChangeLog entry for PR lto/55466 Modified: trunk/gcc/ChangeLog-2012 trunk/gcc/lto/ChangeLog
[Bug lto/55466] [4.8 Regression] Revision 191466 destroyed DWARF debug info
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55466 --- Comment #11 from hjl at gcc dot gnu.org hjl at gcc dot gnu.org 2012-12-10 14:44:00 UTC --- Author: hjl Date: Mon Dec 10 14:43:54 2012 New Revision: 194359 URL: http://gcc.gnu.org/viewcvs?root=gccview=revrev=194359 Log: Record the global variables if WPA isn't enabled PR lto/55466 * lto-symtab.c (lto_symtab_merge_decls_1): Don't record the prevailing variable. * lto.c (lto_register_var_decl_in_symtab): Don't record static variables. (lto_main): Record the global variables if WPA isn't enabled. Modified: trunk/gcc/ChangeLog trunk/gcc/lto-symtab.c trunk/gcc/lto/lto.c
[Bug lto/55466] [4.8 Regression] Revision 191466 destroyed DWARF debug info
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55466 H.J. Lu hjl.tools at gmail dot com changed: What|Removed |Added Status|NEW |RESOLVED Resolution||FIXED --- Comment #12 from H.J. Lu hjl.tools at gmail dot com 2012-12-10 16:39:40 UTC --- Fixed.
[Bug lto/55466] [4.8 Regression] Revision 191466 destroyed DWARF debug info
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55466 Richard Biener rguenth at gcc dot gnu.org changed: What|Removed |Added Priority|P3 |P1 --- Comment #8 from Richard Biener rguenth at gcc dot gnu.org 2012-12-07 10:42:42 UTC --- Only LTRANS should be affected - WPA definitely does not need any of this (rest_of_decl_compilation). LTRANS OTOH does not need any type / symtab merging. Merged WPA/LTRANS phase of course complicates things here. What I can't see is why this all should make a difference at LTRANS? Do we garbage-collect unused globals there before wrapping up global decls? Do we somehow not ship them to the correct LTRANS units? We'd wanted to get rid of lto_global_var_decls orginally (replace it by symtab). At the moment it's _only_ used for calling rest_of_decl_compilation on globals (and for static we call that twice ...). So, HJ, your patch does look reasonable for 4.8 - can you give it proper testing and submit it? OTOH the LTO path should not call rest_of_decl_compilation but sth more specific ... (most of it is disabled for the LTO path anyway).
[Bug lto/55466] [4.8 Regression] Revision 191466 destroyed DWARF debug info
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55466
--- Comment #9 from H.J. Lu hjl.tools at gmail dot com 2012-12-07 13:02:12
UTC ---
I am testing this patch:
---
diff --git a/gcc/lto-symtab.c b/gcc/lto-symtab.c
index 0b0cdac..295fd37 100644
--- a/gcc/lto-symtab.c
+++ b/gcc/lto-symtab.c
@@ -443,10 +443,6 @@ lto_symtab_merge_decls_1 (symtab_node first)
symtab_prevail_in_asm_name_hash (prevailing);
- /* Record the prevailing variable. */
- if (TREE_CODE (prevailing-symbol.decl) == VAR_DECL)
-vec_safe_push (lto_global_var_decls, prevailing-symbol.decl);
-
/* Diagnose mismatched objects. */
for (e = prevailing-symbol.next_sharing_asm_name;
e; e = e-symbol.next_sharing_asm_name)
diff --git a/gcc/lto/lto.c b/gcc/lto/lto.c
index 376af85..c637ec8 100644
--- a/gcc/lto/lto.c
+++ b/gcc/lto/lto.c
@@ -3083,8 +3083,16 @@ read_cgraph_and_symbols (unsigned nfiles, const char
**fnames)
supports inlining, so we can push it here by hand. In future we need to
stream
this field into ltrans compilation. */
if (flag_ltrans)
-FOR_EACH_DEFINED_FUNCTION (node)
- node-ipa_transforms_to_apply.safe_push
((ipa_opt_pass)pass_ipa_inline);
+{
+ struct varpool_node *vnode;
+
+ FOR_EACH_DEFINED_FUNCTION (node)
+node-ipa_transforms_to_apply.safe_push ((ipa_opt_pass)pass_ipa_inline);
+
+ /* Record the global variables. */
+ FOR_EACH_DEFINED_VARIABLE (vnode)
+vec_safe_push (lto_global_var_decls, vnode-symbol.decl);
+}
timevar_pop (TV_IPA_LTO_CGRAPH_MERGE);
---
[Bug lto/55466] [4.8 Regression] Revision 191466 destroyed DWARF debug info
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55466
--- Comment #10 from H.J. Lu hjl.tools at gmail dot com 2012-12-07 18:49:10
UTC ---
(In reply to comment #7)
This patch:
diff --git a/gcc/lto-symtab.c b/gcc/lto-symtab.c
index 0b0cdac..295fd37 100644
--- a/gcc/lto-symtab.c
+++ b/gcc/lto-symtab.c
@@ -443,10 +443,6 @@ lto_symtab_merge_decls_1 (symtab_node first)
symtab_prevail_in_asm_name_hash (prevailing);
- /* Record the prevailing variable. */
- if (TREE_CODE (prevailing-symbol.decl) == VAR_DECL)
-vec_safe_push (lto_global_var_decls, prevailing-symbol.decl);
-
/* Diagnose mismatched objects. */
for (e = prevailing-symbol.next_sharing_asm_name;
e; e = e-symbol.next_sharing_asm_name)
diff --git a/gcc/lto/lto.c b/gcc/lto/lto.c
index 376af85..177fbfc 100644
--- a/gcc/lto/lto.c
+++ b/gcc/lto/lto.c
@@ -2910,6 +2910,7 @@ read_cgraph_and_symbols (unsigned nfiles, const char
**fnames)
struct cgraph_node *node;
int count = 0;
struct lto_file_decl_data **decl_data;
+ struct varpool_node *vnode;
init_cgraph ();
@@ -3088,6 +3089,10 @@ read_cgraph_and_symbols (unsigned nfiles, const char
**fnames)
timevar_pop (TV_IPA_LTO_CGRAPH_MERGE);
+ /* Record the global variables. */
+ FOR_EACH_DEFINED_VARIABLE (vnode)
+vec_safe_push (lto_global_var_decls, vnode-symbol.decl);
+
timevar_push (TV_IPA_LTO_DECL_INIT_IO);
/* Indicate that the cgraph is built and ready. */
or
diff --git a/gcc/lto-symtab.c b/gcc/lto-symtab.c
index 0b0cdac..295fd37 100644
--- a/gcc/lto-symtab.c
+++ b/gcc/lto-symtab.c
@@ -443,10 +443,6 @@ lto_symtab_merge_decls_1 (symtab_node first)
symtab_prevail_in_asm_name_hash (prevailing);
- /* Record the prevailing variable. */
- if (TREE_CODE (prevailing-symbol.decl) == VAR_DECL)
-vec_safe_push (lto_global_var_decls, prevailing-symbol.decl);
-
/* Diagnose mismatched objects. */
for (e = prevailing-symbol.next_sharing_asm_name;
e; e = e-symbol.next_sharing_asm_name)
diff --git a/gcc/lto/lto.c b/gcc/lto/lto.c
index 376af85..c7e1100 100644
--- a/gcc/lto/lto.c
+++ b/gcc/lto/lto.c
@@ -3373,6 +3373,8 @@ lto_main (void)
if (!seen_error ())
{
+ struct varpool_node *vnode;
+
/* If WPA is enabled analyze the whole call graph and create an
optimization plan. Otherwise, read in all the function
bodies and continue with optimization. */
@@ -3398,6 +3400,10 @@ lto_main (void)
if (flag_lto_report)
print_lto_report_1 ();
}
+
+ /* Record the global variables. */
+ FOR_EACH_DEFINED_VARIABLE (vnode)
+vec_safe_push (lto_global_var_decls, vnode-symbol.decl);
}
/* Here we make LTO pretend to be a parser. */
seem to work.
It doesn't work. When gcc is configured with
--enable-languages=c,c++,fortran,java,lto,objc,obj-c++,go, I got
lto1: internal compiler error: in add_AT_specification, at dwarf2out.c:3985
0x629ad9 add_AT_specification
/export/gnu/import/git/gcc/gcc/dwarf2out.c:3985
0x64dabb gen_variable_die
/export/gnu/import/git/gcc/gcc/dwarf2out.c:18327
0x65336b gen_decl_die
/export/gnu/import/git/gcc/gcc/dwarf2out.c:20033
0x653fcd dwarf2out_decl(tree_node*)
/export/gnu/import/git/gcc/gcc/dwarf2out.c:20348
0x6535f9 dwarf2out_global_decl
/export/gnu/import/git/gcc/gcc/dwarf2out.c:20083
0x997703 emit_debug_global_declarations(tree_node**, int)
/export/gnu/import/git/gcc/gcc/toplev.c:530
0x521aaa lto_write_globals
/export/gnu/import/git/gcc/gcc/lto/lto-lang.c:1067
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See http://gcc.gnu.org/bugs.html for instructions.
make[6]: *** [/tmp/cc3yYR7d.ltrans4.ltrans.o] Error 1
lto-wrapper: make returned 2 exit status
lto-wrapper: make returned 2 exit status
/usr/local/x86_64-unknown-linux-gnu/bin/ld: lto-wrapper failed
collect2: error: ld returned 1 exit status
make[5]: *** [go1] Error 1
[Bug lto/55466] [4.8 Regression] Revision 191466 destroyed DWARF debug info
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55466 --- Comment #5 from Jan Hubicka hubicka at gcc dot gnu.org 2012-11-29 18:52:27 UTC --- Created attachment 28829 -- http://gcc.gnu.org/bugzilla/attachment.cgi?id=28829 Proposed fix I suppose something across these lines should do the trick. I am not sure what exactly is the codition for var to be needed to go through wrapup_global_decl. Also I think types are usually going in there, too.
[Bug lto/55466] [4.8 Regression] Revision 191466 destroyed DWARF debug info
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55466 --- Comment #6 from H.J. Lu hjl.tools at gmail dot com 2012-11-29 19:07:23 UTC --- (In reply to comment #5) Created attachment 28829 [details] Proposed fix I suppose something across these lines should do the trick. I am not sure what exactly is the codition for var to be needed to go through wrapup_global_decl. Also I think types are usually going in there, too. It doesn't work: lto1: internal compiler error: Segmentation fault 0x994661 crash_signal /export/gnu/import/git/gcc/gcc/toplev.c:334 0x5206c8 gt_ggc_mx_lang_tree_node(void*) ./gtype-lto.h:37 0x522623 gt_ggc_mx_lang_tree_node(void*) ./gtype-lto.h:389 0x522539 gt_ggc_mx_lang_tree_node(void*) ./gtype-lto.h:380 0x5399ab gt_ggc_ma_gimple_type_leader ./gt-lto-lto.h:154 0x7419c4 ggc_mark_root_tab /export/gnu/import/git/gcc/gcc/ggc-common.c:138 0x741a74 ggc_mark_roots() /export/gnu/import/git/gcc/gcc/ggc-common.c:157 0x5433e5 ggc_collect() /export/gnu/import/git/gcc/gcc/ggc-page.c:2087 0x5388b4 read_cgraph_and_symbols /export/gnu/import/git/gcc/gcc/lto/lto.c:2993 0x5393c9 lto_main() /export/gnu/import/git/gcc/gcc/lto/lto.c:3383 Please submit a full bug report, with preprocessed source if appropriate. Please include the complete backtrace with any bug report. See http://gcc.gnu.org/bugs.html for instructions.
[Bug lto/55466] [4.8 Regression] Revision 191466 destroyed DWARF debug info
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55466
--- Comment #7 from H.J. Lu hjl.tools at gmail dot com 2012-11-29 19:08:28
UTC ---
This patch:
diff --git a/gcc/lto-symtab.c b/gcc/lto-symtab.c
index 0b0cdac..295fd37 100644
--- a/gcc/lto-symtab.c
+++ b/gcc/lto-symtab.c
@@ -443,10 +443,6 @@ lto_symtab_merge_decls_1 (symtab_node first)
symtab_prevail_in_asm_name_hash (prevailing);
- /* Record the prevailing variable. */
- if (TREE_CODE (prevailing-symbol.decl) == VAR_DECL)
-vec_safe_push (lto_global_var_decls, prevailing-symbol.decl);
-
/* Diagnose mismatched objects. */
for (e = prevailing-symbol.next_sharing_asm_name;
e; e = e-symbol.next_sharing_asm_name)
diff --git a/gcc/lto/lto.c b/gcc/lto/lto.c
index 376af85..177fbfc 100644
--- a/gcc/lto/lto.c
+++ b/gcc/lto/lto.c
@@ -2910,6 +2910,7 @@ read_cgraph_and_symbols (unsigned nfiles, const char
**fnames)
struct cgraph_node *node;
int count = 0;
struct lto_file_decl_data **decl_data;
+ struct varpool_node *vnode;
init_cgraph ();
@@ -3088,6 +3089,10 @@ read_cgraph_and_symbols (unsigned nfiles, const char
**fnames)
timevar_pop (TV_IPA_LTO_CGRAPH_MERGE);
+ /* Record the global variables. */
+ FOR_EACH_DEFINED_VARIABLE (vnode)
+vec_safe_push (lto_global_var_decls, vnode-symbol.decl);
+
timevar_push (TV_IPA_LTO_DECL_INIT_IO);
/* Indicate that the cgraph is built and ready. */
or
diff --git a/gcc/lto-symtab.c b/gcc/lto-symtab.c
index 0b0cdac..295fd37 100644
--- a/gcc/lto-symtab.c
+++ b/gcc/lto-symtab.c
@@ -443,10 +443,6 @@ lto_symtab_merge_decls_1 (symtab_node first)
symtab_prevail_in_asm_name_hash (prevailing);
- /* Record the prevailing variable. */
- if (TREE_CODE (prevailing-symbol.decl) == VAR_DECL)
-vec_safe_push (lto_global_var_decls, prevailing-symbol.decl);
-
/* Diagnose mismatched objects. */
for (e = prevailing-symbol.next_sharing_asm_name;
e; e = e-symbol.next_sharing_asm_name)
diff --git a/gcc/lto/lto.c b/gcc/lto/lto.c
index 376af85..c7e1100 100644
--- a/gcc/lto/lto.c
+++ b/gcc/lto/lto.c
@@ -3373,6 +3373,8 @@ lto_main (void)
if (!seen_error ())
{
+ struct varpool_node *vnode;
+
/* If WPA is enabled analyze the whole call graph and create an
optimization plan. Otherwise, read in all the function
bodies and continue with optimization. */
@@ -3398,6 +3400,10 @@ lto_main (void)
if (flag_lto_report)
print_lto_report_1 ();
}
+
+ /* Record the global variables. */
+ FOR_EACH_DEFINED_VARIABLE (vnode)
+vec_safe_push (lto_global_var_decls, vnode-symbol.decl);
}
/* Here we make LTO pretend to be a parser. */
seem to work.
[Bug lto/55466] [4.8 Regression] Revision 191466 destroyed DWARF debug info
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55466
H.J. Lu hjl.tools at gmail dot com changed:
What|Removed |Added
Status|UNCONFIRMED |NEW
Last reconfirmed||2012-11-28
Ever Confirmed|0 |1
--- Comment #4 from H.J. Lu hjl.tools at gmail dot com 2012-11-28 21:26:30
UTC ---
The problem is in
static void
lto_write_globals (void)
{
tree *vec = lto_global_var_decls-address ();
int len = lto_global_var_decls-length ();
wrapup_global_declarations (vec, len);
emit_debug_global_declarations (vec, len);
vec_free (lto_global_var_decls);
}
LTO no longer maintains its own symbol table and it uses varpool for
variables instead. lto_global_var_decls is almost empty. That
is why debug info on variables is lost.
[Bug lto/55466] [4.8 Regression] Revision 191466 destroyed DWARF debug info
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55466 --- Comment #1 from Jan Hubicka hubicka at ucw dot cz 2012-11-26 12:45:23 UTC --- /export/project/git/gcc-regression-bootstrap/master/191466/bld/gcc/cc1...done. (gdb) whatis global_options type = data variable, no debug info (gdb) whatis cl_options type = data variable, no debug info (gdb) whatis cl_enums type = data variable, no debug info (gdb) whatis cl_enums_count type = data variable, no debug info (gdb) whatis global_options_set type = data variable, no debug info (gdb) whatis sched_max_luid type = data variable, no debug info (gdb) Hmm, I suppose this is because we no longer merge symbols that are not part of symtab, but used only for debugging Honza
[Bug lto/55466] [4.8 Regression] Revision 191466 destroyed DWARF debug info
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55466 Richard Biener rguenth at gcc dot gnu.org changed: What|Removed |Added Target Milestone|--- |4.8.0
[Bug lto/55466] [4.8 Regression] Revision 191466 destroyed DWARF debug info
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55466 --- Comment #2 from Richard Biener rguenth at gcc dot gnu.org 2012-11-26 15:57:37 UTC --- (In reply to comment #1) /export/project/git/gcc-regression-bootstrap/master/191466/bld/gcc/cc1...done. (gdb) whatis global_options type = data variable, no debug info (gdb) whatis cl_options type = data variable, no debug info (gdb) whatis cl_enums type = data variable, no debug info (gdb) whatis cl_enums_count type = data variable, no debug info (gdb) whatis global_options_set type = data variable, no debug info (gdb) whatis sched_max_luid type = data variable, no debug info (gdb) Hmm, I suppose this is because we no longer merge symbols that are not part of symtab, but used only for debugging Honza global_options is certainly used. Aggressively removing unused vars is ok even if that drops debug info for them.
[Bug lto/55466] [4.8 Regression] Revision 191466 destroyed DWARF debug info
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55466 --- Comment #3 from H.J. Lu hjl.tools at gmail dot com 2012-11-26 16:36:10 UTC --- (In reply to comment #2) Hmm, I suppose this is because we no longer merge symbols that are not part of symtab, but used only for debugging Honza global_options is certainly used. Aggressively removing unused vars is ok even if that drops debug info for them. We lost debug info on most, if not all, used data variables. It seems that their type infos are also gone. We can't tell extern int *foo; from extern int foo[];
