From: "Alex R. Mosteo" <devnull@mailinator.com>
Subject: Re: GNAT Spitbol segmentation fault
Date: Thu, 18 Jan 2007 18:00:38 +0100
Date: 2007-01-18T18:00:38+01:00 [thread overview]
Message-ID: <519ncnF1i57o2U2@mid.individual.net> (raw)
In-Reply-To: 9f7484-bof.ln1@newserver.thecreems.com
Jeffrey Creem wrote:
> Alex R. Mosteo wrote:
>> Hello,
>>
>> before filing a bug report I'd like to hear your opinion to rule out a
>> mistake on my part. I'm using the excellent Gnat.Spitbol.Patterns package
>> to extract some patterns from large bodies of text. I'm doing it with
>> this scheme:
>>
>> declare
>> Text : aliased Vstring := <initial text>;
>> Target : aliased Vstring;
>>
>> Patt : constant Pattern := Some_Patterns ** Target;
>> begin
>> while Match (Text, Target, "") loop
>> -- This extracts a Target string and removes it from the text.
>> -- It doesn't matter if the surrounding text causes new
>> aftermatches. Do_Something_With (Target);
>> end loop;
>> end;
>>
>> Very rarely I get a Storage_Error and segment violation that kills the
>> program. Running inside gdb I get this backtrace:
>>
>> #0 0xb7ddf37c in memcpy () from /lib/tls/i686/cmov/libc.so.6
>> #1 0x081b7d8d in ada.strings.fixed.replace_slice ()
>> #2 0x081bd6cf in ada.strings.unbounded.replace_slice ()
>> #3 0x081d4f5e in gnat.spitbol.patterns.match ()
>>
>> Unfortunately, address2line doesn't make any valid source lines from
>> these addresses, I suppose because the gdb wrapping (but this is just a
>> guess).
>>
>> If you have used Gnat Spitbol before, could you comment if I'm doing
>> something risky? This is with gnat gpl 2006 in linux x86
>>
>>
>
> Any chance this is a simple matter of blowing the stack someplace?
> Compile with -fstack-check and/or try increasing the stack space of the
> task that is doing this work.
I'm already compiling with it, but it's true that it isn't 100% reliable so
it's worth a try. The spitbol package also checks some internal stack, but
perhaps its size is larger than the default for tasks.
next prev parent reply other threads:[~2007-01-18 17:00 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-01-18 12:33 GNAT Spitbol segmentation fault Alex R. Mosteo
2007-01-18 12:55 ` Jeffrey Creem
2007-01-18 17:00 ` Alex R. Mosteo [this message]
2007-02-01 10:36 ` Alex R. Mosteo
2007-01-18 14:32 ` Georg Bauhaus
2007-01-18 17:00 ` Alex R. Mosteo
2007-01-18 22:31 ` Simon Wright
2007-01-19 9:32 ` Alex R. Mosteo
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