https://openeuphoria.org/forum/135284.wc
libmytest.c
/* libmytest */
#include <stdio.h>
double hello(double x)
{
printf("Hello! Your number was %g\n",x);
return x*2.0;
}
int main()
{
return 1;
}
libmytest.e
include std/dll.e
atom mylib = open_dll("libmytest.so")
atom fn = define_c_func(mylib,"hello",{C_DOUBLE},C_DOUBLE)
printf(1,"Got back: %g\n", c_func(fn,{123.456}))
build
gcc -shared -o libmytest.so libmytest.c
trace
$ gdb eui
GNU gdb (Ubuntu 8.1.1-0ubuntu1) 8.1.1
Reading symbols from eui...(no debugging symbols found)...done.
(gdb) break hello
Function "hello" not defined.
Make breakpoint pending on future shared library load? (y or [n]) y
Breakpoint 1 (hello) pending.
(gdb) run libmytest.e
Starting program: /usr/local/bin/eui libmytest.e
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
Breakpoint 1, 0x00007ffff701f62e in hello () from ./libmytest.so
(gdb) bt
#0 0x00007ffff701f62e in hello () from ./libmytest.so
#1 0x000000000057b074 in call_c ()
#2 0x00000000005780e3 in do_exec ()
#3 0x0000000000578a63 in Execute ()
#4 0x000000000057d301 in start_backend ()
#5 0x000000000057def8 in machine ()
#6 0x00000000004274be in _68BackEnd ()
#7 0x00000000004fe69c in _2BackEnd ()
#8 0x00000000004fa93a in _74main ()
#9 0x000000000041e0bf in main ()
(gdb) cont
Continuing.
Hello! Your number was 123.456
Breakpoint 1, 0x00007ffff701f62e in hello () from ./libmytest.so
(gdb) bt
#0 0x00007ffff701f62e in hello () from ./libmytest.so
#1 0x000000000057a590 in icall_x86_64 ()
#2 0x000000000057b09d in call_c ()
#3 0x00000000005780e3 in do_exec ()
#4 0x0000000000578a63 in Execute ()
#5 0x000000000057d301 in start_backend ()
#6 0x000000000057def8 in machine ()
#7 0x00000000004274be in _68BackEnd ()
#8 0x00000000004fe69c in _2BackEnd ()
#9 0x00000000004fa93a in _74main ()
#10 0x000000000041e0bf in main ()
(gdb) cont
Continuing.
Hello! Your number was 123.456
Got back: 246.912
warning: Temporarily disabling breakpoints for unloaded shared library "./libmytest.so"
[Inferior 1 (process 2575) exited normally]
(gdb) quit
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