Dave Korn wrote:
> Ok, for some reason it appears that libCore.dll.a exports symbols from
> libstdc++:
>
> dkad...@ubik /work/root/test $ nm /work/root/lib/libCore.dll.a |grep
> St9exception 71d6b958 d .rdata$_ZTISt9exception 71d6ff40 d
> .rdata$_ZTSSt9exception 71d6b958 D __ZTISt9exception 71d6ff40 D
> __ZTSSt9exception
>
>
> Looks like the DLL got linked against static libstdc++, while the app links
> against shared libstdc++?
Nope, it uses -shared correctly. Nor is the problem down to the auto-export
routines failing to recognize libstdc++ and inadvertently re-exporting its
symbols
(cf. libnamencmp). In fact, the re-exported symbols come from one of the .o
files
from which the DLL is composed:
dkad...@ubik /work/root
$ nm core/base/src/TSystem.o | grep St9exception
00000000 r .rdata$_ZTISt9exception
00000000 r .rdata$_ZTSSt9exception
00000000 R __ZTISt9exception
00000000 R __ZTSSt9exception
dkad...@ubik /work/root
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:
dkad...@ubik /work/root
$ g++-4 -O2 -pipe -Wall -Woverloaded-virtual -Iinclude -I/usr/X11R6/include
-o ./TSystem.2.o -c core/base/src/TSystem.cxx
dkad...@ubik /work/root
$ nm ./TSystem.2.o | grep St9exception rtua
U __ZTISt9exception
dkad...@ubik /work/root
$
So I'll now try rebuilding and retesting without _DLL defined anywhere and see
if it solves the problem.
cheers,
DaveK
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