[Bug debug/66535] New: segfault in gen_subprogram_die after debug-early merge

[Bug debug/66535] New: segfault in gen_subprogram_die after debug-early merge

[ebotcazou at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66535

            Bug ID: 66535
           Summary: segfault in gen_subprogram_die after debug-early merge
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: debug
          Assignee: unassigned at gcc dot gnu.org
          Reporter: ebotcazou at gcc dot gnu.org
                CC: aldyh at gcc dot gnu.org
  Target Milestone: ---

Created attachment 35776
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=35776&action=edit
Testcase to be gnatchop'ed

The debug-early merge has introduced a crash on the attached Ada testcase:

eric@polaris:~/build/gcc/native> gcc/xgcc -Bgcc -S debug4.adb -g

raised STORAGE_ERROR : stack overflow or erroneous memory access

Program received signal SIGSEGV, Segmentation fault.
0x0000000000b3685c in gen_subprogram_die (decl=0x7ffff53928c0, context_die=0x0)
    at /home/eric/gnat/gnat-head/src/gcc/dwarf2out.c:18793
18793              || old_die->die_parent->die_tag == DW_TAG_module

old_die->die_parent is NULL.

The testcase can be added as-is to the gnat.dg/ testsuite:

  gnat.dg/debug4.adb
  gnat.dg/debug4_pkg.adb
  gnat.dg/debug4_pkg.ads

[Bug debug/66535] segfault in gen_subprogram_die after debug-early merge

[aldyh at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66535

Aldy Hernandez <aldyh at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2015-06-15
           Assignee|unassigned at gcc dot gnu.org      |aldyh at gcc dot gnu.org
     Ever confirmed|0                           |1

--- Comment #1 from Aldy Hernandez <aldyh at gcc dot gnu.org> ---
Mine.

[Bug debug/66535] segfault in gen_subprogram_die after debug-early merge

[aldyh at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66535

--- Comment #2 from Aldy Hernandez <aldyh at gcc dot gnu.org> ---
Author: aldyh
Date: Mon Jun 15 16:34:53 2015
New Revision: 224486

URL: https://gcc.gnu.org/viewcvs?rev=224486&root=gcc&view=rev
Log:
        PR debug/66535
        * dwarf2out.c (gen_subprogram_die): Do not check a parent's tag if
        there is no parent.

Added:
    trunk/gcc/testsuite/gnat.dg/debug4.adb
    trunk/gcc/testsuite/gnat.dg/debug4_pkg.adb
    trunk/gcc/testsuite/gnat.dg/debug4_pkg.ads
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/dwarf2out.c

[Bug debug/66535] segfault in gen_subprogram_die after debug-early merge

[aldyh at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66535

Aldy Hernandez <aldyh at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|---                         |FIXED

--- Comment #3 from Aldy Hernandez <aldyh at gcc dot gnu.org> ---
Fixed in mainline.

[Bug debug/66535] segfault in gen_subprogram_die after debug-early merge

[ebotcazou at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66535

--- Comment #4 from Eric Botcazou <ebotcazou at gcc dot gnu.org> ---
Thanks for the quick fix!