1 /* xstrerror.c -- jacket routine for more robust strerror() usage. 2 Fri Jun 16 18:30:00 1995 Pat Rankin <rankin (at) 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 } 80
