liberror

#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

__thread static char* __error = NULL;

#define raize(fmt, ...)                                                        \
    do {                                                                       \
        size_t errlen = snprintf(NULL, 0, (fmt), ##__VA_ARGS__);               \
        __error       = realloc(__error, errlen);                              \
        sprintf(__error, (fmt), ##__VA_ARGS__);                                \
    } while (0)

#define fcatch(fd, fmt)                                                        \
    do {                                                                       \
        fprintf((fd), (fmt), __error);                                         \
        catch ();                                                              \
    } while (0)

static inline void catch () {
    free(__error);
    __error = NULL;
}

#define error (__error != NULL)

int test(int a) {
    if (a > 10) {
        raize("invalid ergument: %d", a);
        return -1;
    }
    return a * a;
}

int main(int argc, const char* argv[]) {
    int x = test(11);
    if (error) {
        fcatch(stderr, "error: %s\n");
        return 1;
    }

    printf("%s\n", "ok");
    return 0;
}