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Subject: Re: An increment to Jon Turney's stackdump2backtrace script
To: The Cygwin Mailing List <cygwin@cygwin.com>
References: <af84c3ce-364e-e058-ac39-ef2713e06cda@maxrnd.com>
From: Jon Turney <jon.turney@dronecode.org.uk>
Message-ID: <8541aec5-b9f1-c9c4-bdc6-2f5940d10bc2@dronecode.org.uk>
Date: Wed, 3 Oct 2018 18:08:17 +0100
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On 01/10/2018 10:20, Mark Geisert wrote:
> For those Cygwin developers who tend to attract stackdump files...
> 
> ..mark (who defines an alias 'bt' to launch the script because he can't 
> get gdb out of his head)

Nice. Thanks.

> OTHERS=`ldd $IMG1 | awk '{print $3}' | sort -r | tr '\\n' ' '`

One thing you should be aware of here is that you are assuming that the 
other DLLs (i) have the same base address locally and on the system 
where the stackdump was generated [an assumption which rebase will tend 
to invalidate], and (ii) don't get relocated.

(The executable and cygwin1.dll don't suffer from this problem, as they 
have fixed addresses in the process memory layout used by cygwin)

For this reason, stackdumps are a weak tool for debugging crashes in 
other DLLs.  There were some patches posted to add DLL load addresses to 
the stackdump, not sure what happened to them...

It would perhaps be better to write a minidump, which captures that 
information (and more...)

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