The following reply was made to PR pascal/1477; it has been noted by GNATS.
From: Waldek Hebisch <hebisch@xxxxxxxxxxxxxxxx>
To: muller@xxxxxxxxxxxxxxxx, gdb-prs@xxxxxxxxxxxxxxxxxx,
hebisch@xxxxxxxxxxxxxxxx, nobody@xxxxxxxxxxxxxxxxxx,
gdb-gnats@xxxxxxxxxxxxxxxxxx
Cc:
Subject: Re: pascal/1477: gdb can not read DWARF-2 debug info about set types
Date: Tue, 20 Feb 2007 22:57:15 +0100 (CET)
> Synopsis: gdb can not read DWARF-2 debug info about set types
>
> Responsible-Changed-From-To: unassigned->muller
> Responsible-Changed-By: muller
> Responsible-Changed-When: Mon Feb 5 16:48:53 2007
> Responsible-Changed-Why:
> Pascal specific
> State-Changed-From-To: open->feedback
> State-Changed-By: muller
> State-Changed-When: Mon Feb 5 16:48:53 2007
> State-Changed-Why:
> Could you please test gdb 6.6, I think that
> this issue should be solved due to an ADA patch.
> ADA language apparently also has sets.
>
> http://sourceware.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gdb&pr=1477
>
The testcase included in the report works now. However, there are still
problems:
- gdb does not recognize the program as a Pascal program (I have to
use 'set language pascal', otherwise I get:
hebisch@iduo2:~$ gcc/gdb-build/gdb/gdb ./a.out
GNU gdb 6.6
Copyright (C) 2006 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB. Type "show warranty" for details.
This GDB was configured as "x86_64-unknown-linux-gnu"...
Using host libthread_db library "/lib/libthread_db.so.1".
(gdb) break _p__M0_main_program
Breakpoint 1 at 0x4029fc: file set1.pas, line 5.
(gdb) run
Starting program: /var/tmp/hebisch/a.out
Breakpoint 1, main program () at set1.pas:6
6 begin
Current language: auto; currently minimal
(gdb) s
7 dummy := [bar];
(gdb) print dummy
$1 = <error reading variable>
(gdb) s
Hello
10 .
(gdb) print dummy
$2 = <error reading variable>
(gdb)
Also, a slightly more complicated program causes troubles:
var
foo: set of 1 .. 42 = [4 .. 27];
i: Integer;
begin
i := 15;
Exclude (foo, i);
i := 3;
Include (foo, i);
if foo = [3 .. 14, 16 .. 27] then
WriteLn ('OK')
else
WriteLn ('failed')
end.
gpc -g sets14b.pas
sets14b.pas:1: warning: missing program header
hebisch@iduo2:~$ gcc/gdb-build/gdb/gdb ./a.out
GNU gdb 6.6
Copyright (C) 2006 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB. Type "show warranty" for details.
This GDB was configured as "x86_64-unknown-linux-gnu"...
Using host libthread_db library "/lib/libthread_db.so.1".
(gdb) break _p__M0_main_program
Breakpoint 1 at 0x4029fc: file sets14b.pas, line 4.
(gdb) run
Starting program: /var/tmp/hebisch/a.out
Breakpoint 1, 0x00000000004029fc in main program () at sets14b.pas:4
4 i: Integer;
Current language: auto; currently minimal
(gdb) print foo
Cannot access memory at address 0x533778
(gdb) set language pascal
Warning: the current language does not match this frame.
(gdb) print foo
Cannot access memory at address 0x533778
(gdb) set language c
(gdb) print *(long *)0x533778
$1 = 268435440
(gdb)
AFAIK Modula-2 has sets and what works now is probably due to Modula-2
patches. However, it seems that Modula-2 handles some aspects quite
different than Pascal.
--
Waldek Hebisch
hebisch@xxxxxxxxxxxxxxxx
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