[ANNOUNCEMENT] Updated: experimental package: gcc4-4.3.2-2

[Dave Korn]

[Bcc's sent to interested third parties]

Dave Korn wrote:

> And the immediate reason for this is the way that TSystem.o is built:
> 
> ------------------------build.log------------------------ 
> g++-4 -O2 -pipe -Wall -Woverloaded-virtual -D_DLL -Iinclude 
>          -I/usr/X11R6/include -o core/base/src/TSystem.o -c 
>          core/base/src/TSystem.cxx
> ------------------------build.log------------------------
> 
> Why is a -D for _DLL present?  That is a reserved definition in the 
> implementation's namespace, and in particular it used when compiling
> libstdc++ itself, where it alters the effect of the library headers to
> declare all the library APIs as dllexport - they are dllimport by default,
> which is what user applications want to see.
> 
> I manually re-ran the compile command without "-D_DLL" and got a good
> object file:

> So I'll now try rebuilding and retesting without _DLL defined anywhere and
> see if it solves the problem.

  Indeed it did.  With the attached patch, build and test both ran to
completion without any errors.  As far as I can see (thanks, Peter R.) the
_DLL definition conveys information from compiler to linker to tell it which
multilib variant to link against.  We have the -shared-libgcc/-static-libgcc
option in the gcc driver and the related specs to serve the same purpose on GNU.

  One disclaimer: this could have side-effects on MinGW, and should be
verified there to make sure, if it's a supported platform.  (Hopefully it'll
be equally correct there, though).

    cheers,
      DaveK


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