Re: [Tinycc-devel] exporting uninitialized global symbols does not work on PE

[grischka]

Robert Hölzl wrote:
> Hello All
>
> When creating a windows DLL you had to export global symbols (either via
> the keyword "dllexport" or via command line parameter "-rdynamic").
> This works fine for functions and global variables that are preinitialized.
>
> But uninizalized variables are not exported (i.e. "int a = 1;" works
> while "int a;" does not work).
>
> The reason is, that "pe_build_exports()" in tccpe.c contains the
> following check to filter all symbols that shall be exported:
>
> if ((sym->st_other & ST_PE_EXPORT)
>     /* export only symbols from actually written sections */
>     && pe->s1->sections[sym->st_shndx]->sh_addr) {
>
>
> The second condition of this if statment is the reason for the bug, as
> uninitialized variables do not
> have a corresponding address in a PE-section (they are generated
> dynamicially on startup).

I removed that check.  Probably it was there for a reason once but
I don't remember what it was.  At best it is not needed anymore.

--- grischka

> Any hints how I could modify that code?
> I am not a PE expert and thus I do not know how uninitialized symbols
> are represented in PE.
>
> Best Regards,
> Robert