Tinyc compiler - libtcc, how to link validation?

Question

im using libtcc to compile c code on the fly. I am going to use it on a cloud computer that will be used over the Internet.

how to use tinyc in memory and related check function?

heres example that comes with tinyc libtcc library?

any help would be wonderful! thank!

/*
 * Simple Test program for libtcc
 *
 * libtcc can be useful to use tcc as a "backend" for a code generator.
 */
#include <stdlib.h>
#include <stdio.h>
#include <string.h>

#include "libtcc.h"

/* this function is called by the generated code */
int add(int a, int b)
{
    return a + b;
}

char my_program[] =
"int fib(int n)\n"
"{\n"
"    if (n <= 2)\n"
"        return 1;\n"
"    else\n"
"        return fib(n-1) + fib(n-2);\n"
"}\n"
"\n"
"int foo(int n)\n"
"{\n"
"    printf(\"Hello World!\\n\");\n"
"    printf(\"fib(%d) = %d\\n\", n, fib(n));\n"
"    printf(\"add(%d, %d) = %d\\n\", n, 2 * n, add(n, 2 * n));\n"
"    return 0;\n"
"}\n";

int main(int argc, char **argv)
{
    TCCState *s;
    int (*func)(int);
    void *mem;
    int size;

    s = tcc_new();
    if (!s) {
        fprintf(stderr, "Could not create tcc state\n");
        exit(1);
    }

    /* if tcclib.h and libtcc1.a are not installed, where can we find them */
    if (argc == 2 && !memcmp(argv[1], "lib_path=",9))
        tcc_set_lib_path(s, argv[1]+9);

    /* MUST BE CALLED before any compilation */
    tcc_set_output_type(s, TCC_OUTPUT_MEMORY);

    if (tcc_compile_string(s, my_program) == -1)
        return 1;

    /* as a test, we add a symbol that the compiled program can use.
       You may also open a dll with tcc_add_dll() and use symbols from that */
    tcc_add_symbol(s, "add", add);

    /* get needed size of the code */
    size = tcc_relocate(s, NULL);
    if (size == -1)
        return 1;

    /* allocate memory and copy the code into it */
    mem = malloc(size);
    tcc_relocate(s, mem);

    /* get entry symbol */
    func = tcc_get_symbol(s, "foo");
    if (!func)
        return 1;

    /* delete the state */
    tcc_delete(s);

    /* run the code */
    func(32);

    free(mem);
    return 0;
}

Answer 1

you can set border checking manually using:

s->do_bounds_check = 1; //s here is TCCState*

just make sure libtcc is compiled with CONFIG_TCC_BCHECK.

you can also enable debugging with:

s->do_debug = 1;

the command line option -bdoes the same to enable border checking (it also allows debugging).