stubs.c: use of undeclared identifier 'PATH_MAX'

[251]

runtime/POSIX/stubs.c uses an undefined PATH_MAX on my Linux system:

char *canonicalize_file_name (const char *name) __attribute__((weak));
char *canonicalize_file_name (const char *name) {
  char *res = malloc(PATH_MAX);
  char *rp_res = realpath(name, res);
  if (!rp_res)
    free(res);
  return rp_res;
}

It's afaik neither in the C standards nor included with the default option -D _GNU_SOURCE. There are multiple options to resolve this issue. Instead of including linux/limits.h I'd recommend using POSIX_C_SOURCE 200809L/ _XOPEN_SOURCE 700 and pruning canonicalize_file_name to:

char *canonicalize_file_name (const char *name) {
  return realpath(name, NULL);
}

Should work for BSD's libc, glibc, musl...

[ccadar]

Thanks, Frank, the latter option is indeed the right thing to do. In fact the man page for canonicalize_file_name says "The call canonicalize_file_name(path) is equivalent to the call realpath(path, NULL).
Would you like to submit a patch via a pull request? Thanks!