xstrerror.c revision 1.1 
1/* xstrerror.c -- jacket routine for more robust strerror() usage.
2   Fri Jun 16 18:30:00 1995  Pat Rankin  <rankin@eql.caltech.edu>
3   This code is in the public domain.  */
4
5#include <stdio.h>
6
7#include "libiberty.h"
8#include "config.h"
9
10#ifdef VMS
11#include <errno.h>
12#if !defined (__STRICT_ANSI__) && !defined (__HIDE_FORBIDDEN_NAMES)
13extern char *strerror PARAMS ((int,...));
14#define DONT_DECLARE_STRERROR
15#endif
16#endif	/* VMS */
17
18#ifndef DONT_DECLARE_STRERROR
19extern char *strerror PARAMS ((int));
20#endif
21
22/* If strerror returns NULL, we'll format the number into a static buffer.  */
23
24#define ERRSTR_FMT "undocumented error #%d"
25static char xstrerror_buf[sizeof ERRSTR_FMT + 20];
26
27/* Like strerror, but result is never a null pointer.  */
28
29char *
30xstrerror (errnum)
31     int errnum;
32{
33  char *errstr;
34#ifdef VMS
35  char *(*vmslib_strerror) PARAMS ((int,...));
36
37  /* Override any possibly-conflicting declaration from system header.  */
38  vmslib_strerror = (char *(*) PARAMS ((int,...))) strerror;
39  /* Second argument matters iff first is EVMSERR, but it's simpler to
40     pass it unconditionally.  `vaxc$errno' is declared in <errno.h>
41     and maintained by the run-time library in parallel to `errno'.
42     We assume that `errnum' corresponds to the last value assigned to
43     errno by the run-time library, hence vaxc$errno will be relevant.  */
44  errstr = (*vmslib_strerror) (errnum, vaxc$errno);
45#else
46  errstr = strerror (errnum);
47#endif
48
49  /* If `errnum' is out of range, result might be NULL.  We'll fix that.  */
50  if (!errstr)
51    {
52      sprintf (xstrerror_buf, ERRSTR_FMT, errnum);
53      errstr = xstrerror_buf;
54    }
55  return errstr;
56}
57