Index: libcfa/src/exception.c =================================================================== --- libcfa/src/exception.c (revision 6f121b8319d9f9ac95e57b58eb4e9e0faddb194e) +++ libcfa/src/exception.c (revision 99fea48f2387ef184355a08834361210b160f651) @@ -10,6 +10,6 @@ // Created On : Mon Jun 26 15:13:00 2017 // Last Modified By : Andrew Beach -// Last Modified On : Tue Apr 14 12:01:00 2020 -// Update Count : 18 +// Last Modified On : Thr May 21 12:18:00 2020 +// Update Count : 20 // @@ -80,5 +80,5 @@ } -void __cfaehm_throw_resume(exception_t * except) { +void __cfaehm_throw_resume(exception_t * except, void (*defaultHandler)(exception_t *)) { struct exception_context_t * context = this_exception_context(); @@ -96,9 +96,7 @@ } + // No handler found, fall back to the default operation. __cfadbg_print_safe(exception, "Unhandled exception\n"); - - // Fall back to termination: - __cfaehm_throw_terminate(except); - // TODO: Default handler for resumption. + defaultHandler(except); } @@ -239,7 +237,14 @@ } +static void __cfaehm_cleanup_default( exception_t ** except ) { + __cfaehm_delete_exception( *except ); + *except = NULL; +} + // The exception that is being thrown must already be stored. -static __attribute__((noreturn)) void __cfaehm_begin_unwind(void) { - if ( ! this_exception_context()->current_exception ) { +static void __cfaehm_begin_unwind(void(*defaultHandler)(exception_t *)) { + struct exception_context_t * context = this_exception_context(); + struct _Unwind_Exception * storage = &this_exception_storage; + if ( NULL == context->current_exception ) { printf("UNWIND ERROR missing exception in begin unwind\n"); abort(); @@ -247,5 +252,6 @@ // Call stdlibc to raise the exception - _Unwind_Reason_Code ret = _Unwind_RaiseException( &this_exception_storage ); + __cfadbg_print_safe(exception, "Begin unwinding (storage &p, context %p)\n", storage, context); + _Unwind_Reason_Code ret = _Unwind_RaiseException( storage ); // If we reach here it means something happened. For resumption to work we need to find a way @@ -256,22 +262,29 @@ // the whole stack. + // We did not simply reach the end of the stack without finding a handler. This is an error. + if ( ret != _URC_END_OF_STACK ) { + printf("UNWIND ERROR %d after raise exception\n", ret); + abort(); + } + // No handler found, go to the default operation. - // Currently this will always be a cancellation. - if ( ret == _URC_END_OF_STACK ) { - __cfadbg_print_safe(exception, "Uncaught exception %p\n", &this_exception_storage); - - __cfaehm_cancel_stack(this_exception_context()->current_exception); - } - - // We did not simply reach the end of the stack without finding a handler. This is an error. - printf("UNWIND ERROR %d after raise exception\n", ret); + __cfadbg_print_safe(exception, "Uncaught exception %p\n", storage); + + __attribute__((cleanup(__cfaehm_cleanup_default))) + exception_t * exception = context->current_exception; + defaultHandler( exception ); +} + +void __cfaehm_throw_terminate( exception_t * val, void (*defaultHandler)(exception_t *) ) { + __cfadbg_print_safe(exception, "Throwing termination exception\n"); + + __cfaehm_allocate_exception( val ); + __cfaehm_begin_unwind( defaultHandler ); +} + +static __attribute__((noreturn)) void __cfaehm_rethrow_adapter( exception_t * except ) { + // TODO: Print some error message. + (void)except; abort(); -} - -void __cfaehm_throw_terminate( exception_t * val ) { - __cfadbg_print_safe(exception, "Throwing termination exception\n"); - - __cfaehm_allocate_exception( val ); - __cfaehm_begin_unwind(); } @@ -279,5 +292,6 @@ __cfadbg_print_safe(exception, "Rethrowing termination exception\n"); - __cfaehm_begin_unwind(); + __cfaehm_begin_unwind( __cfaehm_rethrow_adapter ); + abort(); } Index: libcfa/src/exception.h =================================================================== --- libcfa/src/exception.h (revision 6f121b8319d9f9ac95e57b58eb4e9e0faddb194e) +++ libcfa/src/exception.h (revision 99fea48f2387ef184355a08834361210b160f651) @@ -10,6 +10,6 @@ // Created On : Mon Jun 26 15:11:00 2017 // Last Modified By : Andrew Beach -// Last Modified On : Fri Mar 27 10:16:00 2020 -// Update Count : 9 +// Last Modified On : Tue May 19 14:17:00 2020 +// Update Count : 10 // @@ -41,7 +41,7 @@ // Used in throw statement translation. -void __cfaehm_throw_terminate(exception_t * except) __attribute__((noreturn)); +void __cfaehm_throw_terminate(exception_t * except, void (*)(exception_t *)); void __cfaehm_rethrow_terminate() __attribute__((noreturn)); -void __cfaehm_throw_resume(exception_t * except); +void __cfaehm_throw_resume(exception_t * except, void (*)(exception_t *)); // Function catches termination exceptions. @@ -72,3 +72,54 @@ #ifdef __cforall } + +// Not all the built-ins can be expressed in C. These can't be +// implemented in the .c file either so they all have to be inline. + +trait is_exception(dtype T) { + /* The first field must be a pointer to a virtual table. + * That virtual table must be a decendent of the base exception virtual tab$ + */ + void mark_exception(T *); + // This is never used and should be a no-op. +}; + +trait is_termination_exception(dtype T | is_exception(T)) { + void defaultTerminationHandler(T &); +}; + +trait is_resumption_exception(dtype T | is_exception(T)) { + void defaultResumptionHandler(T &); +}; + +forall(dtype T | is_termination_exception(T)) +static inline void $throw(T & except) { + __cfaehm_throw_terminate( + (exception_t *)&except, + (void(*)(exception_t *))defaultTerminationHandler + ); +} + +forall(dtype T | is_resumption_exception(T)) +static inline void $throwResume(T & except) { + __cfaehm_throw_resume( + (exception_t *)&except, + (void(*)(exception_t *))defaultResumptionHandler + ); +} + +forall(dtype T | is_exception(T)) +static inline void cancel_stack(T & except) __attribute__((noreturn)) { + __cfaehm_cancel_stack( (exception_t *)&except ); +} + +forall(dtype T | is_exception(T)) +static inline void defaultTerminationHandler(T & except) { + return cancel_stack( except ); +} + +forall(dtype T | is_exception(T)) +static inline void defaultResumptionHandler(T & except) { + throw except; +} + #endif Index: libcfa/src/exception.hfa =================================================================== --- libcfa/src/exception.hfa (revision 6f121b8319d9f9ac95e57b58eb4e9e0faddb194e) +++ libcfa/src/exception.hfa (revision 99fea48f2387ef184355a08834361210b160f651) @@ -10,18 +10,7 @@ // Created On : Thu Apr 7 10:25:00 2020 // Last Modified By : Andrew Beach -// Last Modified On : Wed Apr 13 15:42:00 2020 -// Update Count : 1 +// Last Modified On : Tue May 19 14:17:00 2020 +// Update Count : 2 // - -trait is_exception(dtype T) { - // The trait system can't describe the actual constrants. - // Unused, should always be a no-op. - void mark_exception(T *); -}; - -forall(dtype T | is_exception(T)) -inline void cancel_stack(T & except) __attribute__((noreturn)) { - __cfaehm_cancel_stack( (exception_t *)&except ); -} // Everything below this line should be considered a patch while the exception