libiberty/xstrerror.c

   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)
  13 extern char *strerror PARAMS ((int,...));
  14 #define DONT_DECLARE_STRERROR
  15 #endif
  16 #endif  /* VMS */
  17
  18 #ifndef DONT_DECLARE_STRERROR
  19 extern 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"
  25 static char xstrerror_buf[sizeof ERRSTR_FMT + 20];
  26
  27 /* Like strerror, but result is never a null pointer.  */
  28
  29 char *
  30 xstrerror (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 }