Hmm, it seems that -rdynamic is a non-standard flag here. Use '-Wl,-E' or '-Wl,--export-dynamic'. Check the ld(1) man page for '-E' and '--export-dynamic' options.
http://www.cim.mcgill.ca/~franco/OpSys-304-427/messages/node59.html On Wed, Nov 29, 2006 at 03:52:37PM +0000, Brian Candler wrote: > I am in the process of trying to port rp-l2tp to openbsd. > > I have a problem with dlopen(). rp-l2tp calls dlopen() to load its > sync-pppd.so module, and this in turn has callbacks to functions defined in > the main program. However under OpenBSD these callbacks fail to link. > > Here's a simple test to demonstrate. > > ==> Makefile <== > all: test1 test2 > > test1: test1.c test.h > gcc -Wall -rdynamic -o test1 test1.c -ldl > > test2: test2.c test.h > gcc -Wall -shared -o test2.so test2.c > > ==> test1.c <== > #include <stdio.h> > #include <stdlib.h> > #include <dlfcn.h> > #include "test.h" > > int bar(const char *msg) > { > fprintf(stderr, "Message: %s\n", msg); > return 0; > } > > int main(int argc, char **argv) { > void *handle; > int (*my_foo)(void); > char *error; > > handle = dlopen ("./test2.so", RTLD_NOW); > if (!handle) { > fprintf (stderr, "%s\n", dlerror()); > exit(1); > } > > dlerror(); /* Clear any existing error */ > *(void **) (&my_foo) = dlsym(handle, "foo"); > if ((error = dlerror()) != NULL) { > fprintf (stderr, "%s\n", error); > exit(1); > } > > (*my_foo)(); > dlclose(handle); > return 0; > } > > ==> test2.c <== > #include "test.h" > > int foo(void) > { > bar("hello, world!"); > return 0; > } > > ==> test.h <== > int foo(void); > int bar(const char *); > > If I run this under Linux (Ubuntu-6.06) it works: > > $ make > gcc -Wall -rdynamic -o test1 test1.c -ldl > gcc -Wall -shared -o test2.so test2.c > $ ./test1 > Message: hello, world! > $ > > However, I don't know what I need to modify to make it work under OpenBSD. > You need to remove the '-dl' from the Makefile for it to compile, but then: > > # make > gcc -Wall -rdynamic -o test1 test1.c > test1.c: In function `main': > test1.c:25: warning: assignment discards qualifiers from pointer target type > gcc -Wall -shared -o test2.so test2.c > # ./test1 > ./test1:./test2.so: undefined symbol 'bar' > Cannot load specified object > # > > Under Linux it seems that '-rdynamic' is the magic incantation, because > without this it also fails. However I don't know what the OpenBSD equivalent > is. > > Could someone provide me with the necessary clue please? > > Thanks, > > Brian. > Dale Rahn [EMAIL PROTECTED]
