[deliverable/binutils-gdb.git] / libiberty / xstrerror.c

/* xstrerror.c -- jacket routine for more robust strerror() usage.
   Fri Jun 16 18:30:00 1995  Pat Rankin  <rankin@eql.caltech.edu>
   This code is in the public domain.  */

/*

@deftypefn Replacement char* xstrerror (int @var{errnum})

Behaves exactly like the standard @code{strerror} function, but
will never return a @code{NULL} pointer.

@end deftypefn

*/

#include <stdio.h>

#include "config.h"
#include "libiberty.h"

#ifdef VMS
#  include <errno.h>
#  if !defined (__STRICT_ANSI__) && !defined (__HIDE_FORBIDDEN_NAMES)
#    ifdef __cplusplus
extern "C" {
#    endif /* __cplusplus */
extern char *strerror (int,...);
#    define DONT_DECLARE_STRERROR
#    ifdef __cplusplus
}
#    endif /* __cplusplus */
#  endif
#endif  /* VMS */


#ifndef DONT_DECLARE_STRERROR
#  ifdef __cplusplus
extern "C" {
#  endif /* __cplusplus */
extern char *strerror (int);
#  ifdef __cplusplus
}
#  endif /* __cplusplus */
#endif

/* If strerror returns NULL, we'll format the number into a static buffer.  */

#define ERRSTR_FMT "undocumented error #%d"
static char xstrerror_buf[sizeof ERRSTR_FMT + 20];

/* Like strerror, but result is never a null pointer.  */

char *
xstrerror (int errnum)
{
  char *errstr;
#ifdef VMS
  char *(*vmslib_strerror) (int,...);

  /* Override any possibly-conflicting declaration from system header.  */
  vmslib_strerror = (char *(*) (int,...)) strerror;
  /* Second argument matters iff first is EVMSERR, but it's simpler to
     pass it unconditionally.  `vaxc$errno' is declared in <errno.h>
     and maintained by the run-time library in parallel to `errno'.
     We assume that `errnum' corresponds to the last value assigned to
     errno by the run-time library, hence vaxc$errno will be relevant.  */
  errstr = (*vmslib_strerror) (errnum, vaxc$errno);
#else
  errstr = strerror (errnum);
#endif

  /* If `errnum' is out of range, result might be NULL.  We'll fix that.  */
  if (!errstr)
    {
      sprintf (xstrerror_buf, ERRSTR_FMT, errnum);
      errstr = xstrerror_buf;
    }
  return errstr;
}
Commit	Line	Data
	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	/*
	6
	7	@deftypefn Replacement char* xstrerror (int @var{errnum})
	8
	9	Behaves exactly like the standard @code{strerror} function, but
	10	will never return a @code{NULL} pointer.
	11
	12	@end deftypefn
	13
	14	*/
	15
	16	#include <stdio.h>
	17
	18	#include "config.h"
	19	#include "libiberty.h"
	20
	21	#ifdef VMS
	22	# include <errno.h>
	23	# if !defined (__STRICT_ANSI__) && !defined (__HIDE_FORBIDDEN_NAMES)
	24	# ifdef __cplusplus
	25	extern "C" {
	26	# endif /* __cplusplus */
	27	extern char *strerror (int,...);
	28	# define DONT_DECLARE_STRERROR
	29	# ifdef __cplusplus
	30	}
	31	# endif /* __cplusplus */
	32	# endif
	33	#endif /* VMS */
	34
	35
	36	#ifndef DONT_DECLARE_STRERROR
	37	# ifdef __cplusplus
	38	extern "C" {
	39	# endif /* __cplusplus */
	40	extern char *strerror (int);
	41	# ifdef __cplusplus
	42	}
	43	# endif /* __cplusplus */
	44	#endif
	45
	46	/* If strerror returns NULL, we'll format the number into a static buffer. */
	47
	48	#define ERRSTR_FMT "undocumented error #%d"
	49	static char xstrerror_buf[sizeof ERRSTR_FMT + 20];
	50
	51	/* Like strerror, but result is never a null pointer. */
	52
	53	char *
	54	xstrerror (int errnum)
	55	{
	56	char *errstr;
	57	#ifdef VMS
	58	char (vmslib_strerror) (int,...);
	59
	60	/* Override any possibly-conflicting declaration from system header. */
	61	vmslib_strerror = (char () (int,...)) strerror;
	62	/* Second argument matters iff first is EVMSERR, but it's simpler to
	63	pass it unconditionally. `vaxc$errno' is declared in <errno.h>
	64	and maintained by the run-time library in parallel to `errno'.
	65	We assume that `errnum' corresponds to the last value assigned to
	66	errno by the run-time library, hence vaxc$errno will be relevant. */
	67	errstr = (*vmslib_strerror) (errnum, vaxc$errno);
	68	#else
	69	errstr = strerror (errnum);
	70	#endif
	71
	72	/* If `errnum' is out of range, result might be NULL. We'll fix that. */
	73	if (!errstr)
	74	{
	75	sprintf (xstrerror_buf, ERRSTR_FMT, errnum);
	76	errstr = xstrerror_buf;
	77	}
	78	return errstr;
	79	}