程式語言 - GNU - libjit - Hello, world!

參考資訊：
https://savannah.gnu.org/git/?group=libjit

main.c

#include <stdio.h>
#include <jit/jit.h>
 
int main(int argc, char *argv[])
{
    int (*pfn)(void);
    jit_type_t puts_params[] = {
        jit_type_create_pointer(jit_type_sys_char, 1)
    };
 
    jit_context_t ctx = jit_context_create();
    jit_context_build_start(ctx);
    jit_type_t sig = jit_type_create_signature(jit_abi_cdecl, jit_type_int, NULL, 0, 0);
    jit_function_t fun = jit_function_create(ctx, sig);
    jit_type_t puts_sig = jit_type_create_signature(jit_abi_cdecl, jit_type_int, puts_params, 1, 0);
    jit_value_t arg = jit_value_create_nint_constant(fun, jit_type_create_pointer(jit_type_sys_char, 1), (jit_nint)"Hello, world!");
    jit_value_t args[] = { arg };
    jit_insn_call_native(fun, "puts", puts, puts_sig, args, 1, 0);
    jit_value_t zero = jit_value_create_nint_constant(fun, jit_type_int, 0);
    jit_insn_return(fun, zero);
    jit_function_compile(fun);
    jit_context_build_end(ctx);
 
    pfn = jit_function_to_closure(fun);
    pfn();
 
    jit_context_destroy(ctx);

    return 0;
}

編譯、執行

$ export LD_LIBRARY_PATH=/usr/local/lib
$ gcc main.c -o test -ljit -ggdb
$ ./test
    Hello, world!

$ gdb ./test
(gdb) b main.c:25
(gdb) r
(gdb) x/10i pfn
   0x7ffff7f2614c:	push   %rbp
   0x7ffff7f2614d:	mov    %rsp,%rbp
   0x7ffff7f26150:	movabs $0x555555556004,%rdi
   0x7ffff7f2615a:	mov    $0x8,%eax
   0x7ffff7f2615f:	call   0x7ffff7d93980 <__GI__IO_puts>
   0x7ffff7f26164:	xor    %eax,%eax
   0x7ffff7f26166:	mov    %rbp,%rsp
   0x7ffff7f26169:	pop    %rbp