[RFC] implement throws type for functions and methods

Zend/tests/exception_types/001.phpt

@@ -0,0 +1,9 @@
+--TEST--
+Testing basic exception type compiler wrong type
+--FILE--
+<?php
+function () throws int { }
+?>
+--EXPECTF--
+Fatal error: Throws type must be an object in %s on line 2
+

Zend/tests/exception_types/002.phpt

@@ -0,0 +1,10 @@
+--TEST--
+Testing basic exception type compiler pass
+--FILE--
+<?php
+function test () throws Exception {}
+?>
+OK
+--EXPECT--
+OK
+

Zend/tests/exception_types/003.phpt

@@ -0,0 +1,12 @@
+--TEST--
+Testing basic exception type compiler pass with return
+--FILE--
+<?php
+function test () : int throws Exception {
+	return 1;
+}
+?>
+OK
+--EXPECT--
+OK
+

Zend/tests/exception_types/004.phpt

@@ -0,0 +1,12 @@
+--TEST--
+Testing basic exception type compiler pass with param
+--FILE--
+<?php
+function test (int $param) throws Exception {
+	return $param;
+}
+?>
+OK
+--EXPECT--
+OK
+

Zend/tests/exception_types/005.phpt

@@ -0,0 +1,21 @@
+--TEST--
+Testing exception type compiler fail inheritance remove throws
+--FILE--
+<?php
+class A {
+	public function throwing () throws Exception {
+
+	}
+}
+
+class B extends A {
+	public function throwing() {
+
+	}
+}
+?>
+--EXPECTF--
+Fatal error: Declaration of B::throwing() must be compatible with A::throwing() throws Exception in %s on line 12
+
+
+

Zend/tests/exception_types/006.phpt

@@ -0,0 +1,21 @@
+--TEST--
+Testing exception type compiler pass inheritance add throws
+--FILE--
+<?php
+class A {
+	public function throwing () {
+
+	}
+}
+
+class B extends A {
+	public function throwing() throws Exception {
+
+	}
+}
+?>
+OK
+--EXPECT--
+OK
+
+

Zend/tests/exception_types/007.phpt

@@ -0,0 +1,21 @@
+--TEST--
+Testing exception type compiler fail inheritance changes throws
+--FILE--
+<?php
+class A {
+	public function throwing () throws Exception {
+
+	}
+}
+
+class B extends A {
+	public function throwing() throws FancyException {
+
+	}
+}
+?>
+--EXPECTF--
+Fatal error: Declaration of B::throwing() throws FancyException must be compatible with A::throwing() throws Exception in %s on line 12
+
+
+

Zend/tests/exception_types/010.phpt

@@ -0,0 +1,20 @@
+--TEST--
+Testing exception type executor fail
+--DESCRIPTION--
+I have no idea how to update Optimizer, so temporarily disabled it
+--INI--
+opcache.optimization_level=0
+--FILE--
+<?php
+function test () throws FancyException {
+	throw new Exception();
+}
+test();
+?>
+--EXPECTF--
+Fatal error: Uncaught TypeError: Exception thrown by test() expected to be an instance of FancyException, instance of Exception thrown in %s:3
+Stack trace:
+#0 %s(5): test()
+#1 {main}
+  thrown in %s on line 3
+

Zend/tests/exception_types/011.phpt

@@ -0,0 +1,17 @@
+--TEST--
+Testing exception type executor pass
+--FILE--
+<?php
+class FancyException extends Exception {}
+
+function test () throws FancyException {
+	throw new FancyException();
+}
+
+try {
+	test();
+} catch (FancyException $ex) {}
+?>
+OK
+--EXPECT--
+OK

Zend/tests/exception_types/012.phpt

@@ -0,0 +1,17 @@
+--TEST--
+Testing exception type executor with return pass
+--FILE--
+<?php
+class FancyException extends Exception {}
+
+function test () : int throws FancyException {
+	throw new FancyException();
+}
+
+try {
+	test();
+} catch (FancyException $ex) {}
+?>
+OK
+--EXPECT--
+OK

Zend/tests/exception_types/013.phpt

@@ -0,0 +1,15 @@
+--TEST--
+Testing exception type executor with return and param pass
+--FILE--
+<?php
+function test (int $param) : int throws Exception {
+	return $param;
+}
+
+try {
+	test(10);
+} catch (FancyException $ex) {}
+?>
+OK
+--EXPECT--
+OK

Zend/zend_ast.c

@@ -70,7 +70,7 @@ ZEND_API zend_ast *zend_ast_create_zval_ex(zval *zv, zend_ast_attr attr) {
 
 ZEND_API zend_ast *zend_ast_create_decl(
 	zend_ast_kind kind, uint32_t flags, uint32_t start_lineno, zend_string *doc_comment,
-	zend_string *name, zend_ast *child0, zend_ast *child1, zend_ast *child2, zend_ast *child3
+	zend_string *name, zend_ast *child0, zend_ast *child1, zend_ast *child2, zend_ast *child3, zend_ast *child4
 ) {
 	zend_ast_decl *ast;
 
@@ -87,6 +87,7 @@ ZEND_API zend_ast *zend_ast_create_decl(
 	ast->child[1] = child1;
 	ast->child[2] = child2;
 	ast->child[3] = child3;
+	ast->child[4] = child4;
 
 	return (zend_ast *) ast;
 }
@@ -505,6 +506,7 @@ static void zend_ast_destroy_ex(zend_ast *ast, zend_bool free) {
 			zend_ast_destroy_ex(decl->child[1], free);
 			zend_ast_destroy_ex(decl->child[2], free);
 			zend_ast_destroy_ex(decl->child[3], free);
+			zend_ast_destroy_ex(decl->child[4], free);
 			break;
 		}
 		default:
@@ -1071,6 +1073,10 @@ static void zend_ast_export_ex(smart_str *str, zend_ast *ast, int priority, int
 				smart_str_appends(str, ": ");
 				zend_ast_export_ns_name(str, decl->child[3], 0, indent);
 			}
+			if (decl->child[4]) {
+				smart_str_appends(str, "throws ");
+				zend_ast_export_ns_name(str, decl->child[4], 0, indent);
+			}
 			if (decl->child[2]) {
 				smart_str_appends(str, " {\n");
 				zend_ast_export_stmt(str, decl->child[2], indent + 1);

Zend/zend_ast.h

@@ -183,7 +183,7 @@ typedef struct _zend_ast_decl {
 	unsigned char *lex_pos;
 	zend_string *doc_comment;
 	zend_string *name;
-	zend_ast *child[4];
+	zend_ast *child[5];
 } zend_ast_decl;
 
 typedef void (*zend_ast_process_t)(zend_ast *ast);
@@ -196,7 +196,7 @@ ZEND_API zend_ast *zend_ast_create(zend_ast_kind kind, ...);
 
 ZEND_API zend_ast *zend_ast_create_decl(
 	zend_ast_kind kind, uint32_t flags, uint32_t start_lineno, zend_string *doc_comment,
-	zend_string *name, zend_ast *child0, zend_ast *child1, zend_ast *child2, zend_ast *child3
+	zend_string *name, zend_ast *child0, zend_ast *child1, zend_ast *child2, zend_ast *child3, zend_ast *child4
 );
 
 ZEND_API zend_ast *zend_ast_create_list(uint32_t init_children, zend_ast_kind kind, ...);

Zend/zend_compile.c

@@ -4239,6 +4239,12 @@ void zend_compile_throw(zend_ast *ast) /* {{{ */
 	znode expr_node;
 	zend_compile_expr(&expr_node, expr_ast);
 
+	if (CG(active_op_array)->fn_flags & ZEND_ACC_HAS_THROWS_TYPE) {
+		zend_op *opline = zend_emit_op(NULL, 
+			ZEND_VERIFY_THROW_TYPE, &expr_node, NULL);
+		zend_alloc_cache_slot(opline->op2.constant);
+	}
+
 	zend_emit_op(NULL, ZEND_THROW, &expr_node, NULL);
 }
 /* }}} */
@@ -5069,18 +5075,44 @@ static void zend_compile_typename(zend_ast *ast, zend_arg_info *arg_info, zend_b
 }
 /* }}} */
 
-void zend_compile_params(zend_ast *ast, zend_ast *return_type_ast) /* {{{ */
+void zend_compile_params(zend_ast *ast, zend_ast *return_type_ast, zend_ast *throws_type_ast) /* {{{ */
 {
 	zend_ast_list *list = zend_ast_get_list(ast);
 	uint32_t i;
 	zend_op_array *op_array = CG(active_op_array);
 	zend_arg_info *arg_infos;
-
+	uint32_t narg_infos = list->children;
+
 	if (return_type_ast) {
-		zend_bool allow_null = 0;
+		narg_infos++;
+	}
+
+	if (throws_type_ast) {
+		narg_infos++;
+	}
+
+	if (!narg_infos) {
+		return;	
+	}
+
+	arg_infos = safe_emalloc(sizeof(zend_arg_info), narg_infos, 0);
+
+	if (throws_type_ast) {
+		memset(arg_infos, 0, sizeof(zend_arg_info));
 
-		/* Use op_array->arg_info[-1] for return type */
-		arg_infos = safe_emalloc(sizeof(zend_arg_info), list->children + 1, 0);
+		zend_compile_typename(throws_type_ast, arg_infos, 0);
+
+		if (!ZEND_TYPE_IS_CLASS(arg_infos->type)) {
+			zend_error_noreturn(E_COMPILE_ERROR, "Throws type must be an object");
+		}
+
+		arg_infos++;
+		op_array->fn_flags |= ZEND_ACC_HAS_THROWS_TYPE;		
+	}
+
+	if (return_type_ast) {
+		zend_bool allow_null = 0;
+
 		arg_infos->name = NULL;
 		arg_infos->pass_by_reference = (op_array->fn_flags & ZEND_ACC_RETURN_REFERENCE) != 0;
 		arg_infos->is_variadic = 0;
@@ -5098,12 +5130,7 @@ void zend_compile_params(zend_ast *ast, zend_ast *return_type_ast) /* {{{ */
 		}
 
 		arg_infos++;
-		op_array->fn_flags |= ZEND_ACC_HAS_RETURN_TYPE;
-	} else {
-		if (list->children == 0) {
-			return;
-		}
-		arg_infos = safe_emalloc(sizeof(zend_arg_info), list->children, 0);
+		op_array->fn_flags |= ZEND_ACC_HAS_RETURN_TYPE;	
 	}
 
 	for (i = 0; i < list->children; ++i) {
@@ -5561,6 +5588,8 @@ void zend_compile_func_decl(znode *result, zend_ast *ast) /* {{{ */
 	zend_ast *uses_ast = decl->child[1];
 	zend_ast *stmt_ast = decl->child[2];
 	zend_ast *return_type_ast = decl->child[3];
+	zend_ast *throws_type_ast = decl->child[4];
+
 	zend_bool is_method = decl->kind == ZEND_AST_METHOD;
 
 	zend_op_array *orig_op_array = CG(active_op_array);
@@ -5607,7 +5636,7 @@ void zend_compile_func_decl(znode *result, zend_ast *ast) /* {{{ */
 		zend_stack_push(&CG(loop_var_stack), (void *) &dummy_var);
 	}
 
-	zend_compile_params(params_ast, return_type_ast);
+	zend_compile_params(params_ast, return_type_ast, throws_type_ast);
 	if (CG(active_op_array)->fn_flags & ZEND_ACC_GENERATOR) {
 		zend_mark_function_as_generator();
 		zend_emit_op(NULL, ZEND_GENERATOR_CREATE, NULL, NULL);

Zend/zend_compile.h

@@ -290,8 +290,15 @@ typedef struct _zend_oparray_context {
 /* Function has a return type (or class has such non-private function) */
 #define ZEND_ACC_HAS_RETURN_TYPE		0x40000000
 
+/* Function has a throws type */
+#define ZEND_ACC_HAS_THROWS_TYPE		0x80000000
+
 /* op_array uses strict mode types */
-#define ZEND_ACC_STRICT_TYPES			0x80000000
+#define ZEND_ACC_STRICT_TYPES			0x10
+
+#define ZEND_THROWS_INFO(func) (func->common.fn_flags & ZEND_ACC_HAS_RETURN_TYPE) ? \
+								func->common.arg_info - 2 : \
+								func->common.arg_info - 1
 
 char *zend_visibility_string(uint32_t fn_flags);
 

Zend/zend_execute.c

@@ -913,6 +913,21 @@ static ZEND_COLD void zend_verify_return_error(
 		fclass, fsep, fname, need_msg, need_kind, need_or_null, given_msg, given_kind);
 }
 
+static ZEND_COLD void zend_verify_throw_error(
+		const zend_function *zf, const zend_class_entry *ce, zval *value)
+{
+	const zend_arg_info *arg_info = ZEND_THROWS_INFO(zf);
+	const char *fname, *fsep, *fclass;
+	const char *need_msg, *need_kind, *need_or_null, *given_msg, *given_kind;
+
+	zend_verify_type_error_common(
+		zf, arg_info, ce, value,
+		&fname, &fsep, &fclass, &need_msg, &need_kind, &need_or_null, &given_msg, &given_kind); 
+
+	zend_type_error("Exception thrown by %s%s%s() expected to %s%s%s, %s%s thrown",
+		fclass, fsep, fname, need_msg, need_kind, need_or_null, given_msg, given_kind);
+}
+
 #if ZEND_DEBUG
 static ZEND_COLD void zend_verify_internal_return_error(
 		const zend_function *zf, const zend_class_entry *ce, zval *value)
@@ -977,6 +992,16 @@ static zend_always_inline void zend_verify_return_type(zend_function *zf, zval *
 	}
 }
 
+static zend_always_inline void zend_verify_throw_type(zend_function *zf, zval *ex, void **cache_slot)
+{
+	zend_arg_info *ex_info = ZEND_THROWS_INFO(zf);
+	zend_class_entry *ce = NULL;
+
+	if (UNEXPECTED(!zend_check_type(ex_info->type, ex, &ce, cache_slot, NULL, NULL, 1))) {
+		zend_verify_throw_error(zf, ce, ex);
+	}
+}
+
 static ZEND_COLD int zend_verify_missing_return_type(zend_function *zf, void **cache_slot)
 {
 	zend_arg_info *ret_info = zf->common.arg_info - 1;