LXR linux/tools/lib/traceevent/tep

   1// SPDX-License-Identifier: LGPL-2.1
   2#undef _GNU_SOURCE
   3#include <string.h>
   4#include <stdio.h>
   5
   6#include "event-parse.h"
   7
   8#undef _PE
   9#define _PE(code, str) str
  10static const char * const tep_error_str[] = {
  11        TEP_ERRORS
  12};
  13#undef _PE
  14
  15/*
  16 * The tools so far have been using the strerror_r() GNU variant, that returns
  17 * a string, be it the buffer passed or something else.
  18 *
  19 * But that, besides being tricky in cases where we expect that the function
  20 * using strerror_r() returns the error formatted in a provided buffer (we have
  21 * to check if it returned something else and copy that instead), breaks the
  22 * build on systems not using glibc, like Alpine Linux, where musl libc is
  23 * used.
  24 *
  25 * So, introduce yet another wrapper, str_error_r(), that has the GNU
  26 * interface, but uses the portable XSI variant of strerror_r(), so that users
  27 * rest asured that the provided buffer is used and it is what is returned.
  28 */
  29int tep_strerror(struct tep_handle *tep __maybe_unused,
  30                 enum tep_errno errnum, char *buf, size_t buflen)
  31{
  32        const char *msg;
  33        int idx;
  34
  35        if (!buflen)
  36                return 0;
  37
  38        if (errnum >= 0) {
  39                int err = strerror_r(errnum, buf, buflen);
  40                buf[buflen - 1] = 0;
  41                return err;
  42        }
  43
  44        if (errnum <= __TEP_ERRNO__START ||
  45            errnum >= __TEP_ERRNO__END)
  46                return -1;
  47
  48        idx = errnum - __TEP_ERRNO__START - 1;
  49        msg = tep_error_str[idx];
  50        snprintf(buf, buflen, "%s", msg);
  51
  52        return 0;
  53}
  54