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Subject:	Re: cppcheck 1.77 Segmentation fault (64-bit)
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From:	David Stacey <drstacey AT tiscali DOT co DOT uk>
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Date:	Sat, 4 Feb 2017 15:57:43 +0000
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On 04/02/17 00:08, David Stacey wrote:
> On 29/01/17 21:04, Jim Reisert AD1C wrote:
>> Best as I can tell, the seg fault is due to having installed the test
>> version of gcc 6.0.  Even uninstalling gcc 6.0 does not fix the
>> problem.  I had to create an entirely new Cygwin-64 environment to get
>> past the problem.
>>
>> I invite you (Dave) to try the experiment yourself.  You would be wise
>> to back up your Cygwin environment before doing this.
>
> I've spent a little time looking into this. As per the stack track you 
> supplied, cppcheck is falling over constructing a std::istringstream 
> with a string passed in to initialise the stream. I'll need to debug 
> this into the STL to work out exactly why the seg fault is occurring.

I'm stuck here, I'm afraid. From what I can deduce, cppcheck is using 
the explicitly instantiated version of std::istringstream in libstdc++, 
but my gdb-foo isn't good enough to work out what's going on past that.

I've taken a good look at the cppcheck code, and I believe that it's 
using the STL correctly. If I'm being picky, cppcheck assumes that the 
std::istringsteam is going to construct successfully, i.e. there doesn't 
seem to be a 'catch' exception handler. But given the small size of the 
strings we're dealing with, it's not too unreasonable to expect the 
string copy to succeed.

Anyway, my assumption at the moment is that this is an issue with libstdc++.

Any thoughts?

Dave.


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