chris@mimsy.UUCP (Chris Torek) (09/10/88)
>In article <13402@mimsy.UUCP> I noted that you can make the VAX trap on integer overflow: >) asm("bispsw $0x20"); /* PSL_IV */ >) p++; >)This program, when run, aborts with a `floating exception' (SIGFPE). In article <7076@cdis-1.uucp> tanner@cdis-1.uucp (Dr. T. Andrews) writes: >I may not be the first one to cast a stone at this example, but have >you considered the possibility that a floating point exception is >manifestly the \fBwrong\fP thing to do in your example? There is no >floating-point math in there. Complain to your vendor. What would you have it called? Here are the possible signals: #define SIGHUP 1 /* hangup */ #define SIGINT 2 /* interrupt */ #define SIGQUIT 3 /* quit */ #define SIGILL 4 /* illegal instruction (not reset when caught) */ #define SIGTRAP 5 /* trace trap (not reset when caught) */ #define SIGIOT 6 /* IOT instruction */ #define SIGABRT SIGIOT /* compatibility */ #define SIGEMT 7 /* EMT instruction */ #define SIGFPE 8 /* floating point exception */ #define SIGKILL 9 /* kill (cannot be caught or ignored) */ #define SIGBUS 10 /* bus error */ #define SIGSEGV 11 /* segmentation violation */ #define SIGSYS 12 /* bad argument to system call */ #define SIGPIPE 13 /* write on a pipe with no one to read it */ #define SIGALRM 14 /* alarm clock */ #define SIGTERM 15 /* software termination signal from kill */ #define SIGURG 16 /* urgent condition on IO channel */ #define SIGSTOP 17 /* sendable stop signal not from tty */ #define SIGTSTP 18 /* stop signal from tty */ #define SIGCONT 19 /* continue a stopped process */ #define SIGCHLD 20 /* to parent on child stop or exit */ #define SIGCLD SIGCHLD /* compatibility */ #define SIGTTIN 21 /* to readers pgrp upon background tty read */ #define SIGTTOU 22 /* like TTIN for output if (tp->t_local<OSTOP) */ #define SIGIO 23 /* input/output possible signal */ #define SIGXCPU 24 /* exceeded CPU time limit */ #define SIGXFSZ 25 /* exceeded file size limit */ #define SIGVTALRM 26 /* virtual time alarm */ #define SIGPROF 27 /* profiling time alarm */ #define SIGWINCH 28 /* window size changes */ #define SIGUSR1 30 /* user defined signal 1 */ #define SIGUSR2 31 /* user defined signal 2 */ You have to squeeze it in somewhere, and in fact the VAX hardware reports integer overflow and floating exceptions with the same trap / fault (`arithmetic exception'). -- In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 7163) Domain: chris@mimsy.umd.edu Path: uunet!mimsy!chris