[Bug debug/54410] New: doubled DW_TAG_template_type_param

[Bug debug/54410] New: doubled DW_TAG_template_type_param

[tromey at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54410

             Bug #: 54410
           Summary: doubled DW_TAG_template_type_param
    Classification: Unclassified
           Product: gcc
           Version: 4.8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: debug
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: tromey@gcc.gnu.org


I'm using a relatively recent git gcc:

commit d789d72be457df9811328179702cab8ac5830465
Author: walt <walt@138bc75d-0d04-0410-961f-82ee72b054a4>
Date:   Mon Aug 27 17:27:04 2012 +0000


I compiled this program, derived from a libstdc++ test case:

#include <unordered_set>
#include <string>

typedef std::unordered_set<std::string> Set;
Set m;

int main()
{
}


The DWARF shows duplicate template arguments for unordered_set.
I think each parameter name should appear just a single time:

 <3><38a8>: Abbrev Number: 46 (DW_TAG_template_type_param)
    <38a9>   DW_AT_name        : (indirect string, offset: 0x6e7): _Value    
    <38ad>   DW_AT_type        : <0x1d44>    
 <3><38b1>: Abbrev Number: 46 (DW_TAG_template_type_param)
    <38b2>   DW_AT_name        : (indirect string, offset: 0x6f29): _Hash    
    <38b6>   DW_AT_type        : <0x379c>    
 <3><38ba>: Abbrev Number: 46 (DW_TAG_template_type_param)
    <38bb>   DW_AT_name        : (indirect string, offset: 0x9ebb): _Pred    
    <38bf>   DW_AT_type        : <0x3934>    
 <3><38c3>: Abbrev Number: 46 (DW_TAG_template_type_param)
    <38c4>   DW_AT_name        : (indirect string, offset: 0x7826): _Alloc    
    <38c8>   DW_AT_type        : <0x453a>    
 <3><38cc>: Abbrev Number: 46 (DW_TAG_template_type_param)
    <38cd>   DW_AT_name        : (indirect string, offset: 0x6e7): _Value    
    <38d1>   DW_AT_type        : <0x1d44>    
 <3><38d5>: Abbrev Number: 46 (DW_TAG_template_type_param)
    <38d6>   DW_AT_name        : (indirect string, offset: 0x6f29): _Hash    
    <38da>   DW_AT_type        : <0x379c>    
 <3><38de>: Abbrev Number: 46 (DW_TAG_template_type_param)
    <38df>   DW_AT_name        : (indirect string, offset: 0x9ebb): _Pred    
    <38e3>   DW_AT_type        : <0x3934>    
 <3><38e7>: Abbrev Number: 46 (DW_TAG_template_type_param)
    <38e8>   DW_AT_name        : (indirect string, offset: 0x7826): _Alloc    
    <38ec>   DW_AT_type        : <0x453a>

[Bug debug/54410] [4.6/4.7/4.8 Regression] doubled DW_TAG_template_type_param

[law at redhat dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54410

Jeffrey A. Law <law at redhat dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |law at redhat dot com
            Summary|doubled                     |[4.6/4.7/4.8 Regression]
                   |DW_TAG_template_type_param  |doubled
                   |                            |DW_TAG_template_type_param

--- Comment #1 from Jeffrey A. Law <law at redhat dot com> 2013-01-25 19:54:54 UTC ---
Based on private email with Tom, GCC 4.5 does not emit duplicates for the
parameter while 4.6 and 4.8 (and presumably 4.7) do.  Adding regression marker.

[Bug debug/54410] [4.6/4.7/4.8 Regression] doubled DW_TAG_template_type_param

[aldyh at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54410

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |aldyh at gcc dot gnu.org
         AssignedTo|unassigned at gcc dot       |aldyh at gcc dot gnu.org
                   |gnu.org                     |

--- Comment #2 from Aldy Hernandez <aldyh at gcc dot gnu.org> 2013-01-31 12:01:31 UTC ---
I'll take a look.  No promises, as I my knowledge of dwarf is right up there
with my knowledge of Chinese.  I may spit this back into the queue in no time.

[Bug debug/54410] [4.6/4.7/4.8 Regression] doubled DW_TAG_template_type_param

[jason at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54410

--- Comment #3 from Jason Merrill <jason at gcc dot gnu.org> 2013-01-31 16:34:07 UTC ---
Author: jason
Date: Thu Jan 31 16:33:57 2013
New Revision: 195613

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=195613
Log:
    PR c++/54410
    * dwarf2out.c (gen_struct_or_union_type_die): Always schedule template
    parameters the first time.
    (gen_scheduled_generic_parms_dies): Check completeness here.

Added:
    trunk/gcc/testsuite/g++.dg/debug/dwarf2/template-params-11.C
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/dwarf2out.c

[Bug debug/54410] [4.6/4.7/4.8 Regression] doubled DW_TAG_template_type_param

[jason at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54410

Jason Merrill <jason at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
                 CC|                            |jason at gcc dot gnu.org
         Resolution|                            |FIXED
         AssignedTo|aldyh at gcc dot gnu.org    |jason at gcc dot gnu.org
   Target Milestone|---                         |4.8.0

--- Comment #4 from Jason Merrill <jason at gcc dot gnu.org> 2013-01-31 16:43:44 UTC ---
Fixed for 4.8.  I don't think this is worth backporting.

Aldy: sorry I forgot to assign this to myself yesterday.