Christopher Faylor wrote: >On Thu, Aug 05, 2004 at 09:09:40AM +0200, Peter Ekberg wrote: >>I have read several messages stating that dlopen does not work for dlls >>that depend on cygwin1.dll. >>(e.g. http://sources.redhat.com/ml/cygwin/2004-06/msg01056.html). >>I have also understood that this is due to some structures not being >>initialized in that case. >> >>Is this dlopen problem limited to non-cygwin apps? I.e. is it true >>that an app that depends directly on the cygwin1.dll is incapable of >>dlopening dlls that depend on cygwin1.dll? > >No, it is not true. dlopen would be pretty worthless if it didn't work >in a standard cygwin program.
Indeed. Knowing that it should work, I was inspired to do some more
tests.
The reason I asked is that the following results in a dll that can't be
dlopened:
foo.c:
------------8<---------------
__declspec(dllexport) int foo(int bar);
int foo(int bar)
{
return bar;
}
------------8<---------------
Build commands:
$ gcc -c foo.c
$ dlltool --dllname pseudo_stubs.dll --exclude-symbols
[EMAIL PROTECTED],[EMAIL PROTECTED],[EMAIL PROTECTED],DllMainCR
[EMAIL PROTECTED],[EMAIL PROTECTED] --output-def foo.def foo.o
$ dllwrap --dllname pseudo_stubs.dll --output-lib pseudo_stubs.dll.a
--def foo.def foo.o -L/usr/lib
However, further tests have shown that if I change the name pseudo_stubs
to foo in the above commands, it works like a charm. Like this:
$ gcc -c foo.c
$ dlltool --dllname foo.dll --exclude-symbols
[EMAIL PROTECTED],[EMAIL PROTECTED],[EMAIL PROTECTED],DllMainCR
[EMAIL PROTECTED],[EMAIL PROTECTED] --output-def foo.def foo.o
$ dllwrap --dllname foo.dll --output-lib foo.dll.a --def foo.def foo.o
-L/usr/lib
I use this program to test whether the resulting dll works:
load.c
------------8<---------------
#include <stdio.h>
#include <dlfcn.h>
char *dlls[] = {
"pseudo_stubs.dll",
"foo.dll",
NULL
};
int main(void)
{
int i;
void *res;
for(i=0; dlls[i]; ++i) {
printf("%s\t", dlls[i]);
res=dlopen(dlls[i], RTLD_LAZY | RTLD_GLOBAL);
if(!res)
printf("%s\n", dlerror());
else
printf("ok\n");
}
return 0;
}
------------8<---------------
I build load.c with "gcc load.c -o load" and ./load produces this
output:
pseudo_stubs.dll dlopen: Win32 error 998
foo.dll ok
Any help on this would be appreciated.
Cheers,
Peter Ekberg
cygcheck.out
Description: cygcheck.out
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