Changeset 22f94a4 for libcfa/src/exception.c

Timestamp:

Aug 11, 2020, 4:40:15 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:

0d070ca

Parents:

07d867b (diff), 129674b (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' into new-ast

File:

• libcfa/src/exception.c (modified) (8 diffs)

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();
 
         __cfadbg_print_safe(exception, "Throwing resumption exception\n");
 
-        __attribute__((cleanup(reset_top_resume)))
-        struct __cfaehm_try_resume_node * original_head = context->top_resume;
-        struct __cfaehm_try_resume_node * current = context->top_resume;
-
-        for ( ; current ; current = current->next) {
-                context->top_resume = current->next;
-                if (current->handler(except)) {
-                        return;
+        {
+                __attribute__((cleanup(reset_top_resume)))
+                struct __cfaehm_try_resume_node * original_head = context->top_resume;
+                struct __cfaehm_try_resume_node * current = context->top_resume;
+
+                for ( ; current ; current = current->next) {
+                        context->top_resume = current->next;
+                        if (current->handler(except)) {
+                                return;
+                        }
                 }
-        }
-
+        } // End the search and return to the top of the stack.
+
+        // 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);
 }
 
@@ -121 +121 @@
 
 
-// TERMINATION ===============================================================
-
-// MEMORY MANAGEMENT (still for integers)
-// May have to move to cfa for constructors and destructors (references).
+// MEMORY MANAGEMENT =========================================================
 
 // How to clean up an exception in various situations.
@@ -203 +200 @@
 }
 
-// If this isn't a rethrow (*except==0), delete the provided exception.
-void __cfaehm_cleanup_terminate( void * except ) {
-        if ( *(void**)except ) __cfaehm_delete_exception( *(exception_t **)except );
-}
+// CANCELLATION ==============================================================
 
 // Function needed by force unwind
@@ -228 +222 @@
 }
 
+// Cancel the current stack, prefroming approprate clean-up and messaging.
+void __cfaehm_cancel_stack( exception_t * exception ) {
+        // TODO: Detect current stack and pick a particular stop-function.
+        _Unwind_Reason_Code ret;
+        ret = _Unwind_ForcedUnwind( &this_exception_storage, _Stop_Fn, (void*)0x22 );
+        printf("UNWIND ERROR %d after force unwind\n", ret);
+        abort();
+}
+
+
+// TERMINATION ===============================================================
+
+// If this isn't a rethrow (*except==0), delete the provided exception.
+void __cfaehm_cleanup_terminate( void * except ) {
+        if ( *(void**)except ) __cfaehm_delete_exception( *(exception_t **)except );
+}
+
+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();
@@ -236 +254 @@
 
         // 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
@@ -245 +264 @@
         // the whole stack.
 
-        if ( ret == _URC_END_OF_STACK ) {
-                // No proper handler was found. This can be handled in many ways, C++ calls std::terminate.
-                // Here we force unwind the stack, basically raising a cancellation.
-                printf("Uncaught exception %p\n", &this_exception_storage);
-
-                ret = _Unwind_ForcedUnwind( &this_exception_storage, _Stop_Fn, (void*)0x22 );
-                printf("UNWIND ERROR %d after force unwind\n", ret);
+        // 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();
         }
 
-        // 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);
+        // No handler found, go to the default operation.
+        __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();
 }
 
@@ -270 +294 @@
         __cfadbg_print_safe(exception, "Rethrowing termination exception\n");
 
-        __cfaehm_begin_unwind();
+        __cfaehm_begin_unwind( __cfaehm_rethrow_adapter );
+        abort();
 }