* [Bug debug/98765] [11 Regression] stripping of LTO debug sections doesn't work anymore since switch to -gdwarf-5 by default
2021-01-20 11:17 [Bug debug/98765] New: [11 Regression] stripping of LTO debug sections doesn't work anymore since switch to -gdwarf-5 by default jakub at gcc dot gnu.org
@ 2021-01-20 11:17 ` jakub at gcc dot gnu.org
2021-01-20 11:58 ` jakub at gcc dot gnu.org
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From: jakub at gcc dot gnu.org @ 2021-01-20 11:17 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98765
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Ever confirmed|0 |1
Status|UNCONFIRMED |NEW
Last reconfirmed| |2021-01-20
Target Milestone|--- |11.0
Priority|P3 |P1
^ permalink raw reply [flat|nested] 8+ messages in thread* [Bug debug/98765] [11 Regression] stripping of LTO debug sections doesn't work anymore since switch to -gdwarf-5 by default
2021-01-20 11:17 [Bug debug/98765] New: [11 Regression] stripping of LTO debug sections doesn't work anymore since switch to -gdwarf-5 by default jakub at gcc dot gnu.org
2021-01-20 11:17 ` [Bug debug/98765] " jakub at gcc dot gnu.org
@ 2021-01-20 11:58 ` jakub at gcc dot gnu.org
2021-01-20 12:09 ` jakub at gcc dot gnu.org
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From: jakub at gcc dot gnu.org @ 2021-01-20 11:58 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98765
--- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Seems to be a gcc bug to me:
.section .gnu.debuglto_.debug_info,"e",@progbits
...
.long .LASF0 # DW_AT_name: "a.c"
.long .LASF1 # DW_AT_comp_dir: "/var/tmp"
.long .Ldebug_line0 # DW_AT_stmt_list
...
.section .gnu.debuglto_.debug_line,"e",@progbits
.Ldebug_line0:
...
.uleb128 0x3 # File names count
.long .LASF0 # File Entry: 0: "a.c"
.byte 0
.long .LASF0 # File Entry: 0: "a.c"
.byte 0
...
.section .gnu.debuglto_.debug_line_str,"eMS",@progbits,1
.LASF0:
.string "a.c"
...
.section .debug_info,"",@progbits
.Ldebug_info1:
.long .LASF0 # DW_AT_name: "a.c"
.long .LASF1 # DW_AT_comp_dir: "/var/tmp"
.quad .Ltext0 # DW_AT_low_pc
.quad .Letext0-.Ltext0 # DW_AT_high_pc
.long .Ldebug_line1 # DW_AT_stmt_list
The references in .debug_info to .LASF0/.LASF1 labels from
.gnu.debuglto_.debug_line_str is what is incorrect.
^ permalink raw reply [flat|nested] 8+ messages in thread* [Bug debug/98765] [11 Regression] stripping of LTO debug sections doesn't work anymore since switch to -gdwarf-5 by default
2021-01-20 11:17 [Bug debug/98765] New: [11 Regression] stripping of LTO debug sections doesn't work anymore since switch to -gdwarf-5 by default jakub at gcc dot gnu.org
2021-01-20 11:17 ` [Bug debug/98765] " jakub at gcc dot gnu.org
2021-01-20 11:58 ` jakub at gcc dot gnu.org
@ 2021-01-20 12:09 ` jakub at gcc dot gnu.org
2021-01-20 12:55 ` jakub at gcc dot gnu.org
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From: jakub at gcc dot gnu.org @ 2021-01-20 12:09 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98765
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Assignee|unassigned at gcc dot gnu.org |jakub at gcc dot gnu.org
Status|NEW |ASSIGNED
^ permalink raw reply [flat|nested] 8+ messages in thread* [Bug debug/98765] [11 Regression] stripping of LTO debug sections doesn't work anymore since switch to -gdwarf-5 by default
2021-01-20 11:17 [Bug debug/98765] New: [11 Regression] stripping of LTO debug sections doesn't work anymore since switch to -gdwarf-5 by default jakub at gcc dot gnu.org
` (2 preceding siblings ...)
2021-01-20 12:09 ` jakub at gcc dot gnu.org
@ 2021-01-20 12:55 ` jakub at gcc dot gnu.org
2021-01-20 13:26 ` jakub at gcc dot gnu.org
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From: jakub at gcc dot gnu.org @ 2021-01-20 12:55 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98765
--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
--- gcc/dwarf2out.c.jj 2021-01-20 08:32:09.612958930 +0100
+++ gcc/dwarf2out.c 2021-01-20 13:49:42.367772872 +0100
@@ -4733,7 +4733,9 @@ int
reset_indirect_string (indirect_string_node **h, void *)
{
struct indirect_string_node *node = *h;
- if (node->form == DW_FORM_strp || node->form == dwarf_FORM (DW_FORM_strx))
+ if (node->form == DW_FORM_strp
+ || node->form == DW_FORM_line_strp
+ || node->form == dwarf_FORM (DW_FORM_strx))
{
free (node->label);
node->label = NULL;
fixes it but the string is then emitted into .debug_str rather than
.debug_line_str in the non-.gnu.debuglto_* case.
^ permalink raw reply [flat|nested] 8+ messages in thread* [Bug debug/98765] [11 Regression] stripping of LTO debug sections doesn't work anymore since switch to -gdwarf-5 by default
2021-01-20 11:17 [Bug debug/98765] New: [11 Regression] stripping of LTO debug sections doesn't work anymore since switch to -gdwarf-5 by default jakub at gcc dot gnu.org
` (3 preceding siblings ...)
2021-01-20 12:55 ` jakub at gcc dot gnu.org
@ 2021-01-20 13:26 ` jakub at gcc dot gnu.org
2021-01-20 17:58 ` cvs-commit at gcc dot gnu.org
2021-01-20 18:02 ` jakub at gcc dot gnu.org
6 siblings, 0 replies; 8+ messages in thread
From: jakub at gcc dot gnu.org @ 2021-01-20 13:26 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98765
--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
--- gcc/dwarf2out.c.jj 2021-01-20 08:32:09.612958930 +0100
+++ gcc/dwarf2out.c 2021-01-20 14:15:14.735459774 +0100
@@ -4733,12 +4733,20 @@ int
reset_indirect_string (indirect_string_node **h, void *)
{
struct indirect_string_node *node = *h;
- if (node->form == DW_FORM_strp || node->form == dwarf_FORM (DW_FORM_strx))
+ if (node->form == DW_FORM_strp
+ || node->form == DW_FORM_line_strp
+ || node->form == dwarf_FORM (DW_FORM_strx))
{
+ bool line_strp = node->form == DW_FORM_line_strp;
free (node->label);
node->label = NULL;
node->form = (dwarf_form) 0;
node->index = 0;
+ if (line_strp)
+ {
+ set_indirect_string (node);
+ node->form = DW_FORM_line_strp;
+ }
}
return 1;
}
@@ -31395,10 +31403,7 @@ dwarf2out_finish (const char *filename)
/* Remove indirect string decisions. */
debug_str_hash->traverse<void *, reset_indirect_string> (NULL);
if (debug_line_str_hash)
- {
- debug_line_str_hash->traverse<void *, reset_indirect_string> (NULL);
- debug_line_str_hash = NULL;
- }
+ debug_line_str_hash->traverse<void *, reset_indirect_string> (NULL);
}
#if ENABLE_ASSERT_CHECKING
emits them in .debug_line_str, but emits also strings that aren't really
needed.
^ permalink raw reply [flat|nested] 8+ messages in thread* [Bug debug/98765] [11 Regression] stripping of LTO debug sections doesn't work anymore since switch to -gdwarf-5 by default
2021-01-20 11:17 [Bug debug/98765] New: [11 Regression] stripping of LTO debug sections doesn't work anymore since switch to -gdwarf-5 by default jakub at gcc dot gnu.org
` (4 preceding siblings ...)
2021-01-20 13:26 ` jakub at gcc dot gnu.org
@ 2021-01-20 17:58 ` cvs-commit at gcc dot gnu.org
2021-01-20 18:02 ` jakub at gcc dot gnu.org
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From: cvs-commit at gcc dot gnu.org @ 2021-01-20 17:58 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98765
--- Comment #4 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Jakub Jelinek <jakub@gcc.gnu.org>:
https://gcc.gnu.org/g:27c792895bd809115c1f70672835b7fdff74d318
commit r11-6820-g27c792895bd809115c1f70672835b7fdff74d318
Author: Jakub Jelinek <jakub@redhat.com>
Date: Wed Jan 20 18:51:04 2021 +0100
debug: Fix up DWARF 5 -g -flto -ffat-lto-objects [PR98765]
As mentioned in the PR, with -gdwarf-5 (or -g now) -flto -ffat-lto-objects,
users can't strip the LTO sections with
strip -p -R .gnu.lto_* -R .gnu.debuglto_* -N __gnu_lto_v1
anymore when GCC is configured against recent binutils.
The problem is that in that case .gnu.debuglto_.debug_line_str section is
then used, which is fine for references to strings in .gnu.debuglto_.*
sections, but not when those references are in .debug_info section too;
those should really reference separate strings in .debug_line_str section.
For .gnu.debuglto_.debug_str vs. .debug_str we handle it right, we
reset_indirect_string the strings and thus force creation of new labels for
the second time.
But for DW_FORM_line_strp as the patch shows, there were multiple problems.
First one was that reset_indirect_string, even when called through traverse
on debug_line_str_hash, didn't do anything at all (fixed by first hunk).
The second bug was that the DW_FORM_line_strp strings, which were supposed
to be only visible through debug_line_str_hash, leaked into debug_str_hash
(second hunk).
And the third thing is that when we reset debug_line_str_hash, we should
still make those strings DW_FORM_line_strp if they are accessed.
One could do it by reinstantiating DW_FORM_line_strp right away in
reset_indirect_string and not clear debug_line_str_hash, but that has the
disadvantage that we then force emitting .debug_line_str strings that
aren't
really needed - we need those from the CU DIEs' DW_AT_name and
DW_AT_comp_dir attributes, but when emitting .debug_line section through
assembler, we don't need to emit the strings we only needed for
.gnu.debuglto_.debug_line which is always emitted by the compiler.
2021-01-20 Jakub Jelinek <jakub@redhat.com>
PR debug/98765
* dwarf2out.c (reset_indirect_string): Also reset indirect strings
with DW_FORM_line_strp form.
(prune_unused_types_update_strings): Don't add into debug_str_hash
indirect strings with DW_FORM_line_strp form.
(adjust_name_comp_dir): New function.
(dwarf2out_finish): Call it on CU DIEs after resetting
debug_line_str_hash.
^ permalink raw reply [flat|nested] 8+ messages in thread* [Bug debug/98765] [11 Regression] stripping of LTO debug sections doesn't work anymore since switch to -gdwarf-5 by default
2021-01-20 11:17 [Bug debug/98765] New: [11 Regression] stripping of LTO debug sections doesn't work anymore since switch to -gdwarf-5 by default jakub at gcc dot gnu.org
` (5 preceding siblings ...)
2021-01-20 17:58 ` cvs-commit at gcc dot gnu.org
@ 2021-01-20 18:02 ` jakub at gcc dot gnu.org
6 siblings, 0 replies; 8+ messages in thread
From: jakub at gcc dot gnu.org @ 2021-01-20 18:02 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98765
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Resolution|--- |FIXED
Status|ASSIGNED |RESOLVED
--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Fixed.
^ permalink raw reply [flat|nested] 8+ messages in thread