Address-sanitized version of https://github.com/rain-1/makes/tree/master/previous-version/makes.c

makes.c

// https://rain-1.github.io/why/why.html
// https://github.com/rain-1/makes/tree/master/previous-version/makes.c
//
// Example usage:
// makes foo foo.c foo.h && gcc -Wall -Wextra -o foo foo.c

#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>

#define NEXT do { argc--; argv++; } while (0)

#define VERBOSE if (verbose)

static const char *usage =
"Usage: %s [OPTION] target prereq [prereq...]\n"
"\n"
"OPTIONS:\n"
"\t -h    Print this help and exit\n"
"\t -v    Increase verbosity\n";

int main(int argc, const char *argv[])
{
    const char *name = argv[0];
    bool verbose = false;
    bool rebuild = false;
    struct stat s1, s2;

    NEXT;

    // At least two non-optional arguments (target and prereq)
    if (argc < 2 || !strcmp("-h", argv[0])) {
        printf(usage, name);
        exit(EXIT_SUCCESS);
    }

    if (!strcmp("-v", argv[0])) {
        if (argc < 3) {
            printf(usage, name);
            exit(EXIT_SUCCESS);
        }
        verbose = 1;
        NEXT;
    }

    if (getenv("MAKES_VERBOSE")) {
        verbose = 1;
    }

    int ret;

    if ((ret = stat(argv[0], &s1)) == -1) {
        VERBOSE fprintf(stderr, "[makes] target \"%s\" does not exist\n", argv[0]);
        rebuild = 1;
    }

    for (int i = 1; i < argc; i++) {
        if ((ret = stat(argv[i], &s2)) == 0) {
            if (s2.st_mtime > s1.st_mtime) {
                VERBOSE fprintf(stderr, "[makes] prerequisite \"%s\" is newer\n", argv[i]);
                rebuild = 1;
            }
        } else {
            perror("stat");
            exit(EXIT_FAILURE);
        }
    }

    return !rebuild;
}