Re: Errors using multiple euphoria shared libraries
- Posted by mattlewis (admin) May 24, 2012
- 983 views
Is this a euphoria issue under linux?, or an issue with the way
linux loads shared libraries with all symbols exported as default?
I am guessing that because both shared libraries under linux share
a lot of underlying euphoria library routines that the system cannot
resolve linkage definitions correctly?
It does not appear to be a euphoria interpreter issue. I wrote some C code to test:
// lib1.h
void lib1_export();
// lib2.h
void lib2_export();
// lib.c
// gcc lib.c -l1 -l2 -o test
#include "lib1.h"
#include "lib2.h"
int main(){
lib1_export();
lib2_export();
return 0;
}
I get the same result. If I switch the linking order libraries, then both calls go to lib2. I added define_c_var() calls to see what was being reported for lib1_export and lib2_export, and the pointers returned were different, however the memory pointed to was identical (a jump table?).
Also:
$ nm lib1.so | grep lib 0000000000011d20 T _1lib1_export 0000000000016ae0 T _3std_library_address 0000000000011d20 T lib1_export $ nm lib2.so | grep lib 0000000000011d20 T _1lib2_export 0000000000016ae0 T _3std_library_address 0000000000011d20 T lib2_export
I guess that they aren't being relocated properly when linked. I built simple shared libs from source:
// lib1.c
gcc -shared -fPIC lib1.c -o lib1.so
#include <stdio.h>
void _1lib1_export(){
puts("inside C lib1_export");
}
void lib1_export() __attribute__ ((alias ("_1lib1_export")));
// lib2.c
// gcc -shared -fPIC lib2.c -o lib2.so
#include <stdio.h>
void _1lib1_export(){
puts("inside C lib1_export");
}
void lib1_export() __attribute__ ((alias ("_1lib1_export")));
Those worked as expected, so I'm not sure why the euphoria translated libraries aren't working...
Matt
