Add initial code for suspending execution

This is just some initial code, which is still quite broken (and needs to be
moved so it can be reused.)

4 files changed, 112 insertions, 9 deletions

diff --git a/Zend/zend_generators.c b/Zend/zend_generators.c
index 21581db2c0..d9ddd75ffb 100644
--- a/Zend/zend_generators.c
+++ b/Zend/zend_generators.c
@@ -25,15 +25,33 @@
 ZEND_API zend_class_entry *zend_ce_generator;
 static zend_object_handlers zend_generator_handlers;
 
-typedef struct _zend_generator {
-	zend_object std;
-	/* nothing more for now */
-} zend_generator;
-
 static void zend_generator_free_storage(zend_generator *generator TSRMLS_DC) /* {{{ */
 {
 	zend_object_std_dtor(&generator->std TSRMLS_CC);
 
+	if (generator->execute_data) {
+		zend_execute_data *execute_data = generator->execute_data;
+
+		if (!execute_data->symbol_table) {
+			int i;
+			for (i = 0; i < execute_data->op_array->last_var; ++i) {
+				if (execute_data->CVs[i]) {
+					zval_ptr_dtor(execute_data->CVs[i]);
+				}
+			}
+		} else {
+			if (EG(symtable_cache_ptr) >= EG(symtable_cache_limit)) {
+				zend_hash_destroy(execute_data->symbol_table);
+				FREE_HASHTABLE(execute_data->symbol_table);
+			} else {
+				zend_hash_clean(execute_data->symbol_table);
+				*(++EG(symtable_cache_ptr)) = execute_data->symbol_table;
+			}
+		}
+
+		efree(execute_data);
+	}
+
 	efree(generator);
 }
 /* }}} */
diff --git a/Zend/zend_generators.h b/Zend/zend_generators.h
index 60899072df..c3b8f455f6 100644
--- a/Zend/zend_generators.h
+++ b/Zend/zend_generators.h
@@ -27,6 +27,13 @@ void zend_register_generator_ce(TSRMLS_D);
 
 extern ZEND_API zend_class_entry *zend_ce_generator;
 
+typedef struct _zend_generator {
+	zend_object std;
+
+	/* The suspended execution context. */
+	zend_execute_data *execute_data;
+} zend_generator;
+
 END_EXTERN_C()
 
 #endif
diff --git a/Zend/zend_vm_def.h b/Zend/zend_vm_def.h
index 20b5633b8a..f4d16be7f9 100644
--- a/Zend/zend_vm_def.h
+++ b/Zend/zend_vm_def.h
@@ -5203,17 +5203,56 @@ ZEND_VM_HANDLER(156, ZEND_SEPARATE, VAR, UNUSED)
 
 ZEND_VM_HANDLER(159, ZEND_SUSPEND_AND_RETURN_GENERATOR, ANY, ANY)
 {
+	zend_bool nested;
+
 	if (EG(return_value_ptr_ptr)) {
 		zval *return_value;
+		zend_generator *generator;
 
 		ALLOC_INIT_ZVAL(return_value);
 		object_init_ex(return_value, zend_ce_generator);
 
 		*EG(return_value_ptr_ptr) = return_value;
+
+		/* back up the execution context */
+		generator = (zend_generator *) zend_object_store_get_object(return_value TSRMLS_CC);
+		generator->execute_data = execute_data;
 	}
 
-	/* for now we just do a normal return without suspension */
-	ZEND_VM_DISPATCH_TO_HELPER(zend_leave_helper);
+	/* restore the previous execution context */
+	EG(current_execute_data) = EX(prev_execute_data);
+	nested = EX(nested);
+
+	/* if there is no return value pointer we are responsible for freeing the
+     * execution data */
+	if (!EG(return_value_ptr_ptr)) {
+		/* something has to be done in here, not sure yet what exactly */
+	}
+
+	EG(opline_ptr) = NULL;
+	if (nested) {
+		/* so we can use EX() again */
+		execute_data = EG(current_execute_data);
+
+		EG(opline_ptr)           = &EX(opline);
+		EG(active_op_array)      = EX(op_array);
+		EG(return_value_ptr_ptr) = EX(original_return_value);
+		EG(active_symbol_table)  = EX(symbol_table);
+		EG(This)                 = EX(current_this);
+		EG(scope)                = EX(current_scope);
+		EG(called_scope)         = EX(current_called_scope);
+		
+		EX(function_state).function  = (zend_function *) EX(op_array);
+		EX(function_state).arguments = NULL;
+
+		EX(object) = EX(current_object);
+		EX(called_scope) = DECODE_CTOR(EX(called_scope));
+
+		zend_vm_stack_clear_multiple(TSRMLS_C);
+	}
+
+	ZEND_VM_INC_OPCODE();
+	ZEND_VM_LEAVE();
 }
 
 ZEND_VM_EXPORT_HELPER(zend_do_fcall, zend_do_fcall_common_helper)
diff --git a/Zend/zend_vm_execute.h b/Zend/zend_vm_execute.h
index d351067cb7..8316a0afb1 100644
--- a/Zend/zend_vm_execute.h
+++ b/Zend/zend_vm_execute.h
@@ -1188,17 +1188,56 @@ static int ZEND_FASTCALL  ZEND_USER_OPCODE_SPEC_HANDLER(ZEND_OPCODE_HANDLER_ARGS
 
 static int ZEND_FASTCALL  ZEND_SUSPEND_AND_RETURN_GENERATOR_SPEC_HANDLER(ZEND_OPCODE_HANDLER_ARGS)
 {
+	zend_bool nested;
+
 	if (EG(return_value_ptr_ptr)) {
 		zval *return_value;
+		zend_generator *generator;
 
 		ALLOC_INIT_ZVAL(return_value);
 		object_init_ex(return_value, zend_ce_generator);
 
 		*EG(return_value_ptr_ptr) = return_value;
+
+		/* back up the execution context */
+		generator = (zend_generator *) zend_object_store_get_object(return_value TSRMLS_CC);
+		generator->execute_data = execute_data;
 	}
 
-	/* for now we just do a normal return without suspension */
-	return zend_leave_helper_SPEC(ZEND_OPCODE_HANDLER_ARGS_PASSTHRU);
+	/* restore the previous execution context */
+	EG(current_execute_data) = EX(prev_execute_data);
+	nested = EX(nested);
+
+	/* if there is no return value pointer we are responsible for freeing the
+     * execution data */
+	if (!EG(return_value_ptr_ptr)) {
+		/* something has to be done in here, not sure yet what exactly */
+	}
+
+	EG(opline_ptr) = NULL;
+	if (nested) {
+		/* so we can use EX() again */
+		execute_data = EG(current_execute_data);
+
+		EG(opline_ptr)           = &EX(opline);
+		EG(active_op_array)      = EX(op_array);
+		EG(return_value_ptr_ptr) = EX(original_return_value);
+		EG(active_symbol_table)  = EX(symbol_table);
+		EG(This)                 = EX(current_this);
+		EG(scope)                = EX(current_scope);
+		EG(called_scope)         = EX(current_called_scope);
+
+		EX(function_state).function  = (zend_function *) EX(op_array);
+		EX(function_state).arguments = NULL;
+
+		EX(object) = EX(current_object);
+		EX(called_scope) = DECODE_CTOR(EX(called_scope));
+
+		zend_vm_stack_clear_multiple(TSRMLS_C);
+	}
+
+	ZEND_VM_INC_OPCODE();
+	ZEND_VM_LEAVE();
 }
 
 static int ZEND_FASTCALL  ZEND_FETCH_CLASS_SPEC_CONST_HANDLER(ZEND_OPCODE_HANDLER_ARGS)