Allow exceptions in __toString()

RFC: https://wiki.php.net/rfc/tostring_exceptions

And convert some object to string conversion related recoverable
fatal errors into Error exceptions.

Improve exception safety of internal code performing string
conversions.

2 files changed, 48 insertions, 32 deletions

diff --git a/ext/reflection/php_reflection.c b/ext/reflection/php_reflection.c
index e6ca3322cb..4623efb3cf 100644
--- a/ext/reflection/php_reflection.c
+++ b/ext/reflection/php_reflection.c
@@ -2263,7 +2263,7 @@ ZEND_METHOD(reflection_parameter, __construct)
 		case IS_ARRAY: {
 				zval *classref;
 				zval *method;
-				zend_string *lcname;
+				zend_string *name, *lcname;
 
 				if (((classref = zend_hash_index_find(Z_ARRVAL_P(reference), 0)) == NULL)
 					|| ((method = zend_hash_index_find(Z_ARRVAL_P(reference), 1)) == NULL))
@@ -2275,27 +2275,38 @@ ZEND_METHOD(reflection_parameter, __construct)
 				if (Z_TYPE_P(classref) == IS_OBJECT) {
 					ce = Z_OBJCE_P(classref);
 				} else {
-					convert_to_string_ex(classref);
-					if ((ce = zend_lookup_class(Z_STR_P(classref))) == NULL) {
+					name = zval_get_string(classref);
+					if (EG(exception)) {
+						return;
+					}
+					if ((ce = zend_lookup_class(name)) == NULL) {
 						zend_throw_exception_ex(reflection_exception_ptr, 0,
-								"Class %s does not exist", Z_STRVAL_P(classref));
+								"Class %s does not exist", ZSTR_VAL(name));
+						zend_string_release(name);
 						return;
 					}
+					zend_string_release(name);
+				}
+
+				name = zval_get_string(method);
+				if (EG(exception)) {
+					return;
 				}
 
-				convert_to_string_ex(method);
-				lcname = zend_string_tolower(Z_STR_P(method));
+				lcname = zend_string_tolower(name);
 				if (Z_TYPE_P(classref) == IS_OBJECT && is_closure_invoke(ce, lcname)
 					&& (fptr = zend_get_closure_invoke_method(Z_OBJ_P(classref))) != NULL)
 				{
 					/* nothing to do. don't set is_closure since is the invoke handler,
 					   not the closure itself */
 				} else if ((fptr = zend_hash_find_ptr(&ce->function_table, lcname)) == NULL) {
+					zend_string_release(name);
 					zend_string_release(lcname);
 					zend_throw_exception_ex(reflection_exception_ptr, 0,
 						"Method %s::%s() does not exist", ZSTR_VAL(ce->name), Z_STRVAL_P(method));
 					return;
 				}
+				zend_string_release(name);
 				zend_string_release(lcname);
 			}
 			break;
@@ -2329,29 +2340,23 @@ ZEND_METHOD(reflection_parameter, __construct)
 	if (Z_TYPE_P(parameter) == IS_LONG) {
 		position= (int)Z_LVAL_P(parameter);
 		if (position < 0 || (uint32_t)position >= num_args) {
-			if (fptr->common.fn_flags & ZEND_ACC_CALL_VIA_TRAMPOLINE) {
-				if (fptr->type != ZEND_OVERLOADED_FUNCTION) {
-					zend_string_release_ex(fptr->common.function_name, 0);
-				}
-				zend_free_trampoline(fptr);
-			}
-			if (is_closure) {
-				zval_ptr_dtor(reference);
-			}
 			_DO_THROW("The parameter specified by its offset could not be found");
-			return;
+			goto failure;
 		}
 	} else {
 		uint32_t i;
 
-		position= -1;
-		convert_to_string_ex(parameter);
+		position = -1;
+		if (!try_convert_to_string(parameter)) {
+			goto failure;
+		}
+
 		if (fptr->type == ZEND_INTERNAL_FUNCTION &&
 		    !(fptr->common.fn_flags & ZEND_ACC_USER_ARG_INFO)) {
 			for (i = 0; i < num_args; i++) {
 				if (arg_info[i].name) {
 					if (strcmp(((zend_internal_arg_info*)arg_info)[i].name, Z_STRVAL_P(parameter)) == 0) {
-						position= i;
+						position = i;
 						break;
 					}
 
@@ -2361,24 +2366,15 @@ ZEND_METHOD(reflection_parameter, __construct)
 			for (i = 0; i < num_args; i++) {
 				if (arg_info[i].name) {
 					if (strcmp(ZSTR_VAL(arg_info[i].name), Z_STRVAL_P(parameter)) == 0) {
-						position= i;
+						position = i;
 						break;
 					}
 				}
 			}
 		}
 		if (position == -1) {
-			if (fptr->common.fn_flags & ZEND_ACC_CALL_VIA_TRAMPOLINE) {
-				if (fptr->type != ZEND_OVERLOADED_FUNCTION) {
-					zend_string_release_ex(fptr->common.function_name, 0);
-				}
-				zend_free_trampoline(fptr);
-			}
-			if (is_closure) {
-				zval_ptr_dtor(reference);
-			}
 			_DO_THROW("The parameter specified by its name could not be found");
-			return;
+			goto failure;
 		}
 	}
 
@@ -2406,6 +2402,18 @@ ZEND_METHOD(reflection_parameter, __construct)
 	} else {
 		ZVAL_NULL(prop_name);
 	}
+	return;
+
+failure:
+	if (fptr->common.fn_flags & ZEND_ACC_CALL_VIA_TRAMPOLINE) {
+		if (fptr->type != ZEND_OVERLOADED_FUNCTION) {
+			zend_string_release_ex(fptr->common.function_name, 0);
+		}
+		zend_free_trampoline(fptr);
+	}
+	if (is_closure) {
+		zval_ptr_dtor(reference);
+	}
 }
 /* }}} */
 
@@ -3692,7 +3700,10 @@ static void reflection_class_object_ctor(INTERNAL_FUNCTION_PARAMETERS, int is_ob
 			ZVAL_COPY(&intern->obj, argument);
 		}
 	} else {
-		convert_to_string_ex(argument);
+		if (!try_convert_to_string(argument)) {
+			return;
+		}
+
 		if ((ce = zend_lookup_class(Z_STR_P(argument))) == NULL) {
 			if (!EG(exception)) {
 				zend_throw_exception_ex(reflection_exception_ptr, -1, "Class %s does not exist", Z_STRVAL_P(argument));
diff --git a/ext/reflection/tests/bug74673.phpt b/ext/reflection/tests/bug74673.phpt
index 8e4e8e3a18..47f7604e8b 100644
--- a/ext/reflection/tests/bug74673.phpt
+++ b/ext/reflection/tests/bug74673.phpt
@@ -19,4 +19,9 @@ $class = new ReflectionClass('A');
 echo $class;
 ?>
 --EXPECTF--
-Fatal error: Method ReflectionClass::__toString() must not throw an exception, caught Exception:  in %sbug74673.php on line %d
+Fatal error: Uncaught Exception in %s:%d
+Stack trace:
+#0 [internal function]: {closure}(2, 'Use of undefine...', %s, %d, Array)
+#1 %s(%d): ReflectionClass->__toString()
+#2 {main}
+  thrown in %s on line %d