Bug 23643
| Summary: | dlopen() can't link to symbols in main program module | ||
|---|---|---|---|
| Product: | Base System | Reporter: | Andrey Sverdlichenko <blaze> |
| Component: | i386 | Assignee: | freebsd-bugs (Nobody) <bugs> |
| Status: | Closed FIXED | ||
| Severity: | Affects Only Me | ||
| Priority: | Normal | ||
| Version: | 4.1.1-STABLE | ||
| Hardware: | Any | ||
| OS: | Any | ||
On 19 Dec 2000, the fast fingers of Andrey Sverdlichenko wrote:
AS> 0:xen:test_so$ make
AS> gcc -fpic -DPIC -O -pipe -Wall -c lib.c
AS> cc -shared -o lib.so lib.o
AS> gcc -g -fpic -DPIC -Wall -o prog main.c
AS>
AS> 0:xen:test_so$ ./prog
AS> dlopen: ./lib.so: Undefined symbol "str"
gcc -g -fpic -DPIC -Wall -export-dynamic -o prog main.c
^^^^^^^^^^^^^^^
man ld
--
Carlos A. M. dos Santos
Federal University of Pelotas Meteorological Research Center
Av. Ildefonso Simoes Lopes 2791 Pelotas, RS, Brasil, CEP 96060-290
WWW: http://www.cpmet.ufpel.tche.br RENPAC (X.25): 153231641
Phone: +55 53 277-6767 FAX: +55 53 277-6722
This PR can be closed. (wrong usage of gcc flags by originator). À State Changed From-To: open->closed Asked and answered - read the dlopen(3) man page, pay particular attention to the NOTES section. |
Call dlopen(..., RTLD_NOW) returns "Undefined symbol" when shared object uses a symbol from main program. How-To-Repeat: Makefile ----------- begin Makefile ----------- prog: lib.so main.c gcc -g -fpic -DPIC -Wall -o prog main.c lib.so: lib.c gcc -fpic -DPIC -O -pipe -Wall -c lib.c cc -shared -o lib.so lib.o clean: rm -f prog *.o *.so ----------- end Makefile --------------- main.c ----------- begin main.c --------------- #include <stdio.h> #include <sys/types.h> #include <dlfcn.h> char *str = "ok"; int main() { static void * lib_so; static void (*lib_so_func)(); lib_so = dlopen("./lib.so", RTLD_NOW | RTLD_GLOBAL); if (!lib_so) { fprintf(stderr, "dlopen: %s\n", dlerror()); return 1; } lib_so_func = dlsym(lib_so, "lib_so_func"); if (!lib_so_func) { fprintf(stderr, "dlsym: %s\n", dlerror()); return 1; } lib_so_func(); return 0; } ----------- end main.c ------------ lib.c ----------- begin lib.c ----------- #include <stdio.h> extern char *str; int lib_so_func() { printf("%s\n", str); return 1; } ----------- end lib.c ----------- 0:xen:test_so$ make gcc -fpic -DPIC -O -pipe -Wall -c lib.c cc -shared -o lib.so lib.o gcc -g -fpic -DPIC -Wall -o prog main.c 0:xen:test_so$ ./prog dlopen: ./lib.so: Undefined symbol "str"