Changeset 2554f24

Timestamp:

Dec 11, 2023, 1:05:50 PM (12 months ago)

Author:

Andrew Beach <ajbeach@…>

Branches:

master

Children:

dab9fb93

Parents:

81da3da4

Message:

Try terminate now does not call the catch function, now they have the same caller. This involved updating some platform dependent code which should be correct in all cases.

Files:

• libcfa/src/exception.c (modified) (6 diffs)
• libcfa/src/exception.h (modified) (2 diffs)
• src/ControlStruct/ExceptTranslate.cpp (modified) (1 diff)

libcfa/src/exception.c

@@ -55 +55 @@
 }
 
+struct __cfaehm_base_exception_t * __cfaehm_get_current_exception(void) {
+        return this_exception_context()->current_exception;
+}
 
 // RESUMPTION ================================================================
@@ -309 +312 @@
                 struct _Unwind_Context * unwind_context)
 {
-
         //__cfadbg_print_safe(exception, "CFA: 0x%lx\n", _Unwind_GetCFA(context));
         __cfadbg_print_safe(exception, "Personality function (%d, %x, %llu, %p, %p):",
@@ -412 +414 @@
                                 _Unwind_Word match_pos =
 #                               if defined( __x86_64 )
+                                    _Unwind_GetCFA(unwind_context);
+#                               elif defined( __i386 )
                                     _Unwind_GetCFA(unwind_context) + 8;
-#                               elif defined( __i386 )
-                                    _Unwind_GetCFA(unwind_context) + 24;
 #                               elif defined( __ARM_ARCH )
-                                    _Unwind_GetCFA(unwind_context) + 40;
+                                    _Unwind_GetCFA(unwind_context) + 16;
 #                               endif
                                 int (*matcher)(exception_t *) = *(int(**)(exception_t *))match_pos;
@@ -480 +482 @@
 // and simply linked from libcfa but there is one problem left, see the exception table for details
 __attribute__((noinline))
-void __cfaehm_try_terminate(void (*try_block)(),
-                void (*catch_block)(int index, exception_t * except),
+int __cfaehm_try_terminate(void (*try_block)(),
                 __attribute__((unused)) int (*match_block)(exception_t * except)) {
         //! volatile int xy = 0;
-        //! printf("%p %p %p %p\n", &try_block, &catch_block, &match_block, &xy);
+        //! printf("%p %p %p\n", &try_block, &match_block, &xy);
 
         // Setup the personality routine and exception table.
@@ -508 +509 @@
 
         // Normal return for when there is no throw.
-        return;
+        return 0;
 
         // Exceptionnal path
@@ -519 +520 @@
         asm volatile (".CATCH:");
 
-        // Exception handler
-        // Note: Saving the exception context on the stack breaks termination exceptions.
-        catch_block( EXCEPT_TO_NODE( this_exception_context()->current_exception )->handler_index,
-                     this_exception_context()->current_exception );
+        return EXCEPT_TO_NODE( this_exception_context()->current_exception )->handler_index;
 }
 

libcfa/src/exception.h

@@ -43 +43 @@
 extern struct __cfavir_type_info __cfatid_exception_t;
 
+struct __cfaehm_base_exception_t * __cfaehm_get_current_exception(void);
 
 void __cfaehm_cancel_stack(exception_t * except) __attribute__((noreturn));
@@ -57 +58 @@
 
 // Function catches termination exceptions.
-void __cfaehm_try_terminate(
+int __cfaehm_try_terminate(
         void (*try_block)(),
-        void (*catch_block)(int index, exception_t * except),
         int (*match_block)(exception_t * except));
 

src/ControlStruct/ExceptTranslate.cpp

@@ -482 +482 @@
                 ast::FunctionDecl * terminate_catch,
                 ast::FunctionDecl * terminate_match ) {
-        // { __cfaehm_try_terminate(`try`, `catch`, `match`); }
-
-        ast::UntypedExpr * caller = new ast::UntypedExpr(loc, new ast::NameExpr(loc,
-                "__cfaehm_try_terminate" ) );
-        caller->args.push_back( new ast::VariableExpr(loc, try_wrapper ) );
-        caller->args.push_back( new ast::VariableExpr(loc, terminate_catch ) );
-        caller->args.push_back( new ast::VariableExpr(loc, terminate_match ) );
-
-        ast::CompoundStmt * callStmt = new ast::CompoundStmt(loc);
-        callStmt->push_back( new ast::ExprStmt( loc, caller ) );
-        return callStmt;
+        // {
+        //     int __handler_index = __cfaehm_try_terminate(`try`, `match`);
+        //     if ( __handler_index ) {
+        //         `catch`( __handler_index, __cfaehm_get_current_exception() );
+        //     }
+        // }
+
+        ast::ObjectDecl * index = new ast::ObjectDecl( loc, "__handler_index",
+                new ast::BasicType( ast::BasicType::SignedInt ),
+                new ast::SingleInit( loc,
+                        new ast::UntypedExpr( loc,
+                                new ast::NameExpr( loc, "__cfaehm_try_terminate" ),
+                                {
+                                        new ast::VariableExpr( loc, try_wrapper ),
+                                        new ast::VariableExpr( loc, terminate_match ),
+                                }
+                        )
+                )
+        );
+
+        return new ast::CompoundStmt( loc, {
+                new ast::DeclStmt( loc, index ),
+                new ast::IfStmt( loc,
+                        new ast::VariableExpr( loc, index ),
+                        new ast::ExprStmt( loc,
+                                new ast::UntypedExpr( loc,
+                                        new ast::VariableExpr( loc, terminate_catch ),
+                                        {
+                                                new ast::VariableExpr( loc, index ),
+                                                new ast::UntypedExpr( loc,
+                                                        new ast::NameExpr( loc, "__cfaehm_get_current_exception" )
+                                                ),
+                                        }
+                                )
+                        )
+                ),
+        } );
 }