This is the mail archive of the cygwin-apps mailing list for the Cygwin project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: 64bit: cygstdc++-6.dll


On Sat, Mar 23, 2013 at 5:50 AM, Corinna Vinschen
<corinna-cygwin@cygwin.com> wrote:
> On Mar 22 19:11, marco atzeri wrote:
>> latest libstdc++6-4.8-20130319-1
>>
>> has at least a missing entry point from previous dll
>>
>> cmake fails with
>> "_ZTVN10_cxxabiv117_class_type_infoE could not be located"
>
> Yaakov built this libstdc++.  As I said in the other mail, I'm not
> exactly a gcc expert and Yaakov is off-list for a couple of days.
>
> However, a quick glance into the symbols exported by libstdc++.a
> shows that the above symbol exists, but with additional leading
> underscores:
>
>   _ZTVN10__cxxabiv117__class_type_infoE
>           ^           ^
>
> The x86_64 ABI does not prepends underscores in front of symbols,
> so there has evidently gone something wrong.  I checked my the Linux
> cross toolchain and it is also using the symbols with additional
> leading underscores.  Off the top of my head I don't see where this
> discrepancy is caused.
>
> Kai, do you have an idea why that could have happened?

Not sure if this helps, but there is a switch for compiling with
leading underscores:

-fleading-underscore
-fno-leading-underscore

We likewise support this when building the crt via:
--disable-leading-underscores
--enable-leading-underscores

Perhaps this has something to do with it?  Maybe something is set as
the default for cygwin, and it needs to be flipped?


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]