/* * signal.c * Implement signal-based exception handling * * Copyright (c) 1996, 1997, 1998, 1999 *	Transvirtual Technologies, Inc.  All rights reserved. * * See the file "license.terms" for information on usage and redistribution  * of this file.  */#include "config.h"#include "debug.h"#include "config-std.h"#include "config-signal.h"#include "config-mem.h"#include "config-setjmp.h"#include "jthread.h"#include "md.h"#if defined(INTERPRETER)#define	DEFINEFRAME()		/* Does nothing */#define	EXCEPTIONPROTO		int sig#define	EXCEPTIONFRAME(f, c)	/* Does nothing */#define	EXCEPTIONFRAMEPTR	0#elif defined(TRANSLATOR)#define	DEFINEFRAME()		exceptionFrame frame#define	EXCEPTIONFRAMEPTR	&frame#endif /* TRANSLATOR */#define SIG_T   void*static void nullException(EXCEPTIONPROTO);static void floatingException(EXCEPTIONPROTO);static exchandler_t nullHandler;static exchandler_t floatingHandler;/* * Setup a signal handler. */voidcatchSignal(int sig, void* handler){	sigset_t nsig;#if defined(HAVE_SIGACTION)	struct sigaction newact;	newact.sa_handler = (SIG_T)handler;	sigemptyset(&newact.sa_mask);	/* we cannot afford to have our signal handlers preempted before	 * they are able to disable interrupts.	 */	sigaddset(&newact.sa_mask, SIGIO);	sigaddset(&newact.sa_mask, SIGALRM);#if defined(SIGVTALRM)	sigaddset(&newact.sa_mask, SIGVTALRM);#endif#if defined(SIGUNUSED)	sigaddset(&newact.sa_mask, SIGUNUSED);#endif	newact.sa_flags = 0;#if defined(SA_SIGINFO)	newact.sa_flags |= SA_SIGINFO;#endif	sigaction(sig, &newact, NULL);#elif defined(HAVE_SIGNAL)	signal(sig, (SIG_T)handler);#else	ABORT();#endif	/* Unblock this signal */	sigemptyset(&nsig);	sigaddset(&nsig, sig);	sigprocmask(SIG_UNBLOCK, &nsig, 0);}/* * Setup the internal exceptions. */voidjthread_initexceptions(exchandler_t _nullHandler,		       exchandler_t _floatingHandler){	nullHandler = _nullHandler;	floatingHandler = _floatingHandler;	if (DBGEXPR(EXCEPTION, false, true)) {		/* Catch signals we need to convert to exceptions */#if defined(SIGSEGV)		catchSignal(SIGSEGV, nullException);#endif#if defined(SIGBUS)		catchSignal(SIGBUS, nullException);#endif#if defined(SIGFPE)		catchSignal(SIGFPE, floatingException);#endif#if defined(SIGPIPE)		catchSignal(SIGPIPE, SIG_IGN);#endif	}}/* * Null exception - catches bad memory accesses. */static voidnullException(EXCEPTIONPROTO){	DEFINEFRAME();	/* These threads are internal to pthreads and shouldn't blow up like this. */	assert(pthread_self() != 0);	/* don't catch the signal if debugging exceptions */	if (DBGEXPR(EXCEPTION, false, true)) {		catchSignal(sig, nullException);	}	EXCEPTIONFRAME(frame, ctx);	nullHandler(EXCEPTIONFRAMEPTR);}/* * Division by zero. */static voidfloatingException(EXCEPTIONPROTO){	DEFINEFRAME();	/* These threads are internal to pthreads and shouldn't blow up like this. */	assert(pthread_self() != 0);	/* don't catch the signal if debugging exceptions */	if (DBGEXPR(EXCEPTION, false, true)) {		catchSignal(sig, floatingException);	}	EXCEPTIONFRAME(frame, ctx);	floatingHandler(EXCEPTIONFRAMEPTR);}/* * we don't really block/unblock any signals here */voidblockAsyncSignals(void){}voidunblockAsyncSignals(void){}