Changeset 99fea48 for libcfa

Timestamp:

May 21, 2020, 5:06:35 PM (5 years ago)

Author:

Thierry Delisle <tdelisle@…>

Branches:

ADT, arm-eh, ast-experimental, enum, forall-pointer-decay, jacob/cs343-translation, master, new-ast, new-ast-unique-expr, pthread-emulation, qualifiedEnum

Children:

0e4df2e, 7119daa

Parents:

6f121b8 (diff), 66ba544 (diff)
Note: this is a merge changeset, the changes displayed below correspond to the merge itself.
Use the (diff) links above to see all the changes relative to each parent.

Message:

Merge branch 'master' of plg.uwaterloo.ca:software/cfa/cfa-cc

Location:

libcfa/src

Files:

• exception.c (modified) (7 diffs)
• exception.h (modified) (3 diffs)
• exception.hfa (modified) (1 diff)

libcfa/src/exception.c

@@ -10 +10 @@
 // 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 +80 @@
 }
 
-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 +96 @@
         }
 
+        // 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 +237 @@
 }
 
+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 +252 @@
 
         // 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 +262 @@
         // 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 +292 @@
         __cfadbg_print_safe(exception, "Rethrowing termination exception\n");
 
-        __cfaehm_begin_unwind();
+        __cfaehm_begin_unwind( __cfaehm_rethrow_adapter );
+        abort();
 }
 

libcfa/src/exception.h

@@ -10 +10 @@
 // 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 +41 @@
 
 // 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 +72 @@
 #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

libcfa/src/exception.hfa

@@ -10 +10 @@
 // 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