Nicholas wrote:
> Hi All,
>
> Gerrit and I were discussing this off-list, but I thought it appropriate
> that I move it to the main list since he has confirmed the problem.
>
> Here's the problem, programs are segfaulting when the are linked to a
> symbol which was aliased using __attribute__((alias)) in a dll. Here is
> a small testcase:
>
>
> foo.c:
> #include <stdio.h>
>
> int __foo (void) {
> printf("foo\r\n");
> return 0;
> }
> int __attribute__ ((alias("__foo"))) foo (void);
>
One problem is that you (or gcc) need to tell ld that 'foo' is function, not
data.
Adding this to file foo.c (after the alias declaration):
__asm__ (".def _foo; .scl 2; .type 32; .endef\n");
would do that.
That fixes the testcase on mingw anyway.
I'm testing a patch now that would make gcc do that too (for aliased
functions).
However, in general,when you do dllexport with code written in straight
assembler, you will need to add a function directive like the one above
so that the linker does the right thing.
(BTW, you've just reminded me of a similar problem in libffi assembly code
that needs to be fixed. Thanks )
Or...
The usual windows way would be to put your aliasing for dllexports in a def
file.
Danny
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