NetBSD/gnu/usr.bin/awk/matherr.c
1993-03-21 09:45:37 +00:00

188 lines
3.6 KiB
C

/********************************************
matherr.c
copyright 1991, Michael D. Brennan
This is a source file for mawk, an implementation of
the AWK programming language.
Mawk is distributed without warranty under the terms of
the GNU General Public License, version 2, 1991.
********************************************/
/*$Log: matherr.c,v $
/*Revision 1.1.1.1 1993/03/21 09:45:37 cgd
/*initial import of 386bsd-0.1 sources
/*
* Revision 1.2 1992/06/02 05:07:35 rich
* Ported to 386bsd. Changes from vax BSD4.3 include usage of
* fmod in libm.a, usage of void pointers, and usage of vfprintf
* in libc.a. Floating point exceptions are not raised when
* they should be, which causes the last fpe test to fail.
*
* Revision 5.1 91/12/05 07:56:18 brennan
* 1.1 pre-release
*
*/
#include "mawk.h"
#include <math.h>
#if FPE_TRAPS_ON
#include <signal.h>
/* machine dependent changes might be needed here */
static void fpe_catch( signal, why)
int signal, why ;
{
#if NOINFO_SIGFPE
/* some systems give no hook to find out what the exception
was -- stuff like this is why people still use fortran
If this fits, #define NOINFO_SIGFPE 1 in your config.h
*/
rt_error("floating point exception, probably overflow") ;
#else
switch(why)
{
case FPE_INTDIV_TRAP :
case FPE_FLTDIV_TRAP :
rt_error("division by zero") ;
case FPE_INTOVF_TRAP :
case FPE_FLTOVF_TRAP :
rt_error("floating point overflow") ;
default :
rt_error("floating point exception") ;
}
#endif
}
void fpe_init()
{ (void) signal(SIGFPE, fpe_catch) ; }
#else /* FPE_TRAPS_ON==0 */
void fpe_init()
{
TURN_OFF_FPE_TRAPS() ;
}
#endif
#if HAVE_MATHERR
#if ! FPE_TRAPS_ON
/* If we are not trapping math errors, we will shutup the library calls
*/
int matherr( e )
struct exception *e ;
{ return 1 ; }
#else /* print error message and exit */
int matherr( e )
struct exception *e ;
{ char *error ;
switch( e->type )
{
case DOMAIN :
case SING :
error = "domain error" ;
break ;
case OVERFLOW :
error = "overflow" ;
break ;
case TLOSS :
case PLOSS :
error = "loss of significance" ;
break ;
case UNDERFLOW :
e->retval = 0.0 ;
return 1 ; /* ignore it */
}
if ( strcmp(e->name, "atan2") == 0 )
rt_error("atan2(%g,%g) : %s" ,
e->arg1, e->arg2, error ) ;
else
rt_error("%s(%g) : %s" , e->name, e->arg1, error) ;
/* won't get here */
return 0 ;
}
#endif /* FPE_TRAPS */
#endif /* HAVE_MATHERR */
/* this is how one gets the libm calls to do the right
thing on bsd43_vax
*/
#ifdef BSD43_VAX
#include <errno.h>
double infnan( arg )
int arg ;
{
switch(arg)
{
case ERANGE : errno = ERANGE ; return HUGE ;
case -ERANGE : errno = EDOM ; return -HUGE ;
default : errno = EDOM ;
}
return 0.0 ;
}
#endif /* BSD43_VAX */
/* This routine is for XENIX-68K 2.3A.
Error check routine to be called after fp arithmetic.
*/
#if SW_FP_CHECK
/* Definitions of bit values in iserr() return value */
#define OVFLOW 2
#define UFLOW 4
#define ZERODIV 8
#define OVFLFIX 32
#define INFNAN 64
void
fpcheck()
{
register int fperrval ;
char *errdesc ;
if ((fperrval = iserr()) == 0)
return ; /* no error */
errdesc = (char *) 0 ;
if (fperrval & INFNAN)
errdesc = "arg is infinity or NAN" ;
else if (fperrval & ZERODIV)
errdesc = "division by zero" ;
else if (fperrval & OVFLOW)
errdesc = "overflow" ;
else if (fperrval & UFLOW)
; /* ignored */
if (errdesc)
rt_error("%s", errdesc) ;
}
#endif