Experimenting with libsafec for C11 safe string function goodness.

libsafec-test.c

#include <stdio.h>      /* printf(), fprintf() */
#include <stdbool.h>
#include <stdint.h>
#include <stdlib.h>     /* atoi() */
#include <string.h>     /* memset(), strlen() */
#include <unistd.h>     /* close() */

#include "safe_lib.h"

/**
 * cc -std=c11 -Wall libsafec-test.c /usr/local/lib/libsafec-1.0.a -I/usr/local/include/libsafec
 */

/**
 * typedef void (*safe_lib_constraint_handler_t)(const char *msg, void *ptr,errno_t error);
 *
 * safe_lib_constraint_handler_t safe_lib_set_constraint_handler(safe_lib_constraint_handler_t handler)
 */

/**
 *  errno_t strcat_s(char *dest, rsize_t dmax, const char *src);
 *
 *  // Alternative naming - conforming to the error codes
 *  errno_t strcat_s(char *s2, rsize_t dmax, const char *s1);
 */

/**
 * The following are defined in `libsafec/include/safe_lib_errno.h`
 */
/// #define EOK ( 0 )
/// #define ESNULLP ( 400 ) /* null ptr */
/// #define ESZEROL ( 401 ) /* length is zero */
/// #define ESLEMAX ( 403 ) /* length exceeds max */
/// #define ESOVRLP ( 404 ) /* overlap undefined */
/// #define ESNOSPC ( 406 ) /* not enough space for s2 */
/// #define ESUNTERM ( 407 ) /* unterminated string */
/// #define ESNOTFND ( 409 ) /* not found */

/**
 * ESNOSPC: "Not enough space for s2"
 *
 * If the `rsize_t dmax` isn't large enough this will be returned.
 */
void strcat_s_exit_on_err(errno_t code);

int main(void)
{
    errno_t code;
    char *dest = malloc(BUFSIZ);
    char *src = "Hello";
    rsize_t limit = BUFSIZ - 1;

    /// printf("BUFSIZ: %d\n", BUFSIZ);
    /// printf("RSIZE_MAX_STR: %lu\n", RSIZE_MAX_STR); // <-- 4096
    /// printf("LIMIT: %zu\n", limit);

    code = strcat_s(dest, limit, src);
    strcat_s_exit_on_err(code);

    printf("[%lu] => \"%s\"\n", strlen(dest), dest);

    // -----------

    char* src2 = ", ";

    code = strcat_s(dest, limit, src2);
    strcat_s_exit_on_err(code);

    printf("[%lu] => \"%s\"\n", strlen(dest), dest);

    // -----------

    char* src3 = "world.";

    code = strcat_s(dest, limit, src3);
    strcat_s_exit_on_err(code);

    printf("[%lu] => \"%s\"\n", strlen(dest), dest);

    // -------
    // CLEANUP
    // -------

    free(dest);
}

void strcat_s_exit_on_err(errno_t code)
{
    if (code == EOK) {
        return;
    }

    fprintf(stderr, "strcat_s() encountered an error: ");

    switch(code)
    {
        case ESNULLP:
            fprintf(stderr, "Null pointer\n");
            break;

        case ESZEROL:
            fprintf(stderr, "Length is zero\n");
            break;

        case ESLEMAX:
            fprintf(stderr, "Length exceeds max\n");
            break;

        case ESOVRLP:
            fprintf(stderr, "Overlap undefined\n");
            break;

        case ESNOSPC:
            fprintf(stderr, "Not enough space for s2\n");
            break;

        case ESUNTERM:
            fprintf(stderr, "Unterminated string\n");
            break;

        case ESNOTFND:
            fprintf(stderr, "Not found\n");
            break;

        default:
            fprintf(stderr, "Unknown error code\n");
            break;
    }

    exit(code);
}