duk_error_longjmp.c

/*
 *  Do a longjmp call, calling the fatal error handler if no
 *  catchpoint exists.
 */

#include "duk_internal.h"

#if defined(DUK_USE_PREFER_SIZE)
DUK_LOCAL void duk__uncaught_minimal(duk_hthread *thr) {
	(void) duk_fatal(thr, "uncaught error");
}
#endif

#if 0
DUK_LOCAL void duk__uncaught_readable(duk_hthread *thr) {
	const char *summary;
	char buf[DUK_USE_FATAL_MAXLEN];

	summary = duk_push_string_tval_readable(thr, &thr->heap->lj.value1);
	DUK_SNPRINTF(buf, sizeof(buf), "uncaught: %s", summary);
	buf[sizeof(buf) - 1] = (char) 0;
	(void) duk_fatal(thr, (const char *) buf);
}
#endif

#if !defined(DUK_USE_PREFER_SIZE)
DUK_LOCAL void duk__uncaught_error_aware(duk_hthread *thr) {
	const char *summary;
	char buf[DUK_USE_FATAL_MAXLEN];

	summary = duk_push_string_tval_readable_error(thr, &thr->heap->lj.value1);
	DUK_ASSERT(summary != NULL);
	DUK_SNPRINTF(buf, sizeof(buf), "uncaught: %s", summary);
	buf[sizeof(buf) - 1] = (char) 0;
	(void) duk_fatal(thr, (const char *) buf);
}
#endif

DUK_INTERNAL void duk_err_longjmp(duk_hthread *thr) {
	DUK_ASSERT(thr != NULL);
	DUK_ASSERT(thr->heap != NULL);

	DUK_DD(DUK_DDPRINT("longjmp error: type=%d iserror=%d value1=%!T value2=%!T",
	                   (int) thr->heap->lj.type, (int) thr->heap->lj.iserror,
	                   &thr->heap->lj.value1, &thr->heap->lj.value2));

	/* Prevent finalizer execution during error handling.  All error
	 * handling sites will process pending finalizers once error handling
	 * is complete and we're ready for the side effects.  Does not prevent
	 * refzero freeing or mark-and-sweep during error handling.
	 *
	 * NOTE: when we come here some calling code may have used DECREF
	 * NORZ macros without an explicit DUK_REFZERO_CHECK_xxx() call.
	 * We don't want to do it here because it would just check for
	 * pending finalizers and we prevent that explicitly.  Instead,
	 * the error catcher will run the finalizers once error handling
	 * is complete.
	 */

	DUK_ASSERT_LJSTATE_SET(thr->heap);

	thr->heap->pf_prevent_count++;
	DUK_ASSERT(thr->heap->pf_prevent_count != 0);  /* Wrap. */

#if defined(DUK_USE_ASSERTIONS)
	/* XXX: set this immediately when longjmp state is set */
	DUK_ASSERT(thr->heap->error_not_allowed == 0);  /* Detect error within critical section. */
	thr->heap->error_not_allowed = 1;
#endif

	DUK_DD(DUK_DDPRINT("about to longjmp, pf_prevent_count=%ld", (long) thr->heap->pf_prevent_count));

#if !defined(DUK_USE_CPP_EXCEPTIONS)
	/* If we don't have a jmpbuf_ptr, there is little we can do except
	 * cause a fatal error.  The caller's expectation is that we never
	 * return.
	 *
	 * With C++ exceptions we now just propagate an uncaught error
	 * instead of invoking the fatal error handler.  Because there's
	 * a dummy jmpbuf for C++ exceptions now, this could be changed.
	 */
	if (!thr->heap->lj.jmpbuf_ptr) {
		DUK_D(DUK_DPRINT("uncaught error: type=%d iserror=%d value1=%!T value2=%!T",
		                 (int) thr->heap->lj.type, (int) thr->heap->lj.iserror,
		                 &thr->heap->lj.value1, &thr->heap->lj.value2));

#if defined(DUK_USE_PREFER_SIZE)
		duk__uncaught_minimal(thr);
#else
		duk__uncaught_error_aware(thr);
#endif
		DUK_UNREACHABLE();
	}
#endif  /* DUK_USE_CPP_EXCEPTIONS */

#if defined(DUK_USE_CPP_EXCEPTIONS)
	{
		duk_internal_exception exc;  /* dummy */
		throw exc;
	}
#else  /* DUK_USE_CPP_EXCEPTIONS */
	DUK_LONGJMP(thr->heap->lj.jmpbuf_ptr->jb);
#endif  /* DUK_USE_CPP_EXCEPTIONS */

	DUK_UNREACHABLE();
}