1*4fee23f9Smrg /* xstrerror.c -- jacket routine for more robust strerror() usage.
2*4fee23f9Smrg Fri Jun 16 18:30:00 1995 Pat Rankin <rankin@eql.caltech.edu>
3*4fee23f9Smrg This code is in the public domain. */
4*4fee23f9Smrg
5*4fee23f9Smrg /*
6*4fee23f9Smrg
7*4fee23f9Smrg @deftypefn Replacement char* xstrerror (int @var{errnum})
8*4fee23f9Smrg
9*4fee23f9Smrg Behaves exactly like the standard @code{strerror} function, but
10*4fee23f9Smrg will never return a @code{NULL} pointer.
11*4fee23f9Smrg
12*4fee23f9Smrg @end deftypefn
13*4fee23f9Smrg
14*4fee23f9Smrg */
15*4fee23f9Smrg
16*4fee23f9Smrg #include <stdio.h>
17*4fee23f9Smrg
18*4fee23f9Smrg #include "config.h"
19*4fee23f9Smrg #include "libiberty.h"
20*4fee23f9Smrg
21*4fee23f9Smrg #ifdef VMS
22*4fee23f9Smrg # include <errno.h>
23*4fee23f9Smrg # if !defined (__STRICT_ANSI__) && !defined (__HIDE_FORBIDDEN_NAMES)
24*4fee23f9Smrg # ifdef __cplusplus
25*4fee23f9Smrg extern "C" {
26*4fee23f9Smrg # endif /* __cplusplus */
27*4fee23f9Smrg extern char *strerror (int,...);
28*4fee23f9Smrg # define DONT_DECLARE_STRERROR
29*4fee23f9Smrg # ifdef __cplusplus
30*4fee23f9Smrg }
31*4fee23f9Smrg # endif /* __cplusplus */
32*4fee23f9Smrg # endif
33*4fee23f9Smrg #endif /* VMS */
34*4fee23f9Smrg
35*4fee23f9Smrg
36*4fee23f9Smrg #ifndef DONT_DECLARE_STRERROR
37*4fee23f9Smrg # ifdef __cplusplus
38*4fee23f9Smrg extern "C" {
39*4fee23f9Smrg # endif /* __cplusplus */
40*4fee23f9Smrg extern char *strerror (int);
41*4fee23f9Smrg # ifdef __cplusplus
42*4fee23f9Smrg }
43*4fee23f9Smrg # endif /* __cplusplus */
44*4fee23f9Smrg #endif
45*4fee23f9Smrg
46*4fee23f9Smrg /* If strerror returns NULL, we'll format the number into a static buffer. */
47*4fee23f9Smrg
48*4fee23f9Smrg #define ERRSTR_FMT "undocumented error #%d"
49*4fee23f9Smrg static char xstrerror_buf[sizeof ERRSTR_FMT + 20];
50*4fee23f9Smrg
51*4fee23f9Smrg /* Like strerror, but result is never a null pointer. */
52*4fee23f9Smrg
53*4fee23f9Smrg char *
xstrerror(int errnum)54*4fee23f9Smrg xstrerror (int errnum)
55*4fee23f9Smrg {
56*4fee23f9Smrg char *errstr;
57*4fee23f9Smrg #ifdef VMS
58*4fee23f9Smrg char *(*vmslib_strerror) (int,...);
59*4fee23f9Smrg
60*4fee23f9Smrg /* Override any possibly-conflicting declaration from system header. */
61*4fee23f9Smrg vmslib_strerror = (char *(*) (int,...)) strerror;
62*4fee23f9Smrg /* Second argument matters iff first is EVMSERR, but it's simpler to
63*4fee23f9Smrg pass it unconditionally. `vaxc$errno' is declared in <errno.h>
64*4fee23f9Smrg and maintained by the run-time library in parallel to `errno'.
65*4fee23f9Smrg We assume that `errnum' corresponds to the last value assigned to
66*4fee23f9Smrg errno by the run-time library, hence vaxc$errno will be relevant. */
67*4fee23f9Smrg errstr = (*vmslib_strerror) (errnum, vaxc$errno);
68*4fee23f9Smrg #else
69*4fee23f9Smrg errstr = strerror (errnum);
70*4fee23f9Smrg #endif
71*4fee23f9Smrg
72*4fee23f9Smrg /* If `errnum' is out of range, result might be NULL. We'll fix that. */
73*4fee23f9Smrg if (!errstr)
74*4fee23f9Smrg {
75*4fee23f9Smrg sprintf (xstrerror_buf, ERRSTR_FMT, errnum);
76*4fee23f9Smrg errstr = xstrerror_buf;
77*4fee23f9Smrg }
78*4fee23f9Smrg return errstr;
79*4fee23f9Smrg }
80