PHP->JS exception propagation

README.md

@@ -48,6 +48,7 @@ class V8Js
 
     const FLAG_NONE = 1;
     const FLAG_FORCE_ARRAY = 2;
+    const FLAG_PROPAGATE_PHP_EXCEPTIONS = 4;
 
     const DEBUG_AUTO_BREAK_NEVER = 1;
     const DEBUG_AUTO_BREAK_ONCE = 2;
@@ -297,3 +298,28 @@ PHP Objects implementing ArrayAccess, Countable
 The above rule that PHP objects are generally converted to JavaScript objects also applies to PHP objects of `ArrayObject` type or other classes, that implement both the `ArrayAccess` and the `Countable` interface -- even so they behave like PHP arrays.
 
 This behaviour can be changed by enabling the php.ini flag `v8js.use_array_access`.  If set, objects of PHP classes that implement the aforementioned interfaces are converted to JavaScript Array-like objects.  This is by-index access of this object results in immediate calls to the `offsetGet` or `offsetSet` PHP methods (effectively this is live-binding of JavaScript against the PHP object).  Such an Array-esque object also supports calling every attached public method of the PHP object + methods of JavaScript's native Array.prototype methods (as long as they are not overloaded by PHP methods).
+
+Exceptions
+==========
+
+If the JavaScript code throws (without catching), causes errors or doesn't
+compile, `V8JsScriptException` exceptions are thrown unless the `V8Js` object
+is constructed with `report_uncaught_exceptions` set `FALSE`.
+
+PHP exceptions that occur due to calls from JavaScript code by default are
+*not* re-thrown into JavaScript context but cause the JavaScript execution to
+be stopped immediately and then are reported at the location calling the JS code.
+
+This behaviour can be changed by setting the `FLAG_PROPAGATE_PHP_EXCEPTIONS`
+flag.  If it is set, PHP exception (objects) are converted to JavaScript
+objects obeying the above rules and re-thrown in JavaScript context.  If they
+are not caught by JavaScript code the execution stops and a
+`V8JsScriptException` is thrown, which has the original PHP exception accessible
+via `getPrevious` method.
+
+V8Js versions 0.2.4 and before did not stop JS code execution on PHP exceptions,
+but silently ignored them (even so succeeding PHP calls from within the same piece
+of JS code were not executed by the PHP engine).  This behaviour is considered as
+a bug and hence was fixed with 0.2.5 release.  Nevertheless there is a 
+compatibility php.ini switch (`v8js.compat_php_exceptions`) which turns previous
+behaviour back on.

php_v8js_macros.h

@@ -80,13 +80,10 @@ extern "C" {
 # define V8JS_CONST (char *)
 #endif
 
-/* Global flags */
-#define V8JS_GLOBAL_SET_FLAGS(isolate,flags)	V8JS_GLOBAL(isolate)->SetHiddenValue(V8JS_SYM("__php_flags__"), V8JS_INT(flags))
-#define V8JS_GLOBAL_GET_FLAGS(isolate)			V8JS_GLOBAL(isolate)->GetHiddenValue(V8JS_SYM("__php_flags__"))->IntegerValue();
-
 /* Options */
 #define V8JS_FLAG_NONE			(1<<0)
 #define V8JS_FLAG_FORCE_ARRAY	(1<<1)
+#define V8JS_FLAG_PROPAGATE_PHP_EXCEPTIONS	(1<<2)
 
 #define V8JS_DEBUG_AUTO_BREAK_NEVER		0
 #define V8JS_DEBUG_AUTO_BREAK_ONCE		1
@@ -124,6 +121,7 @@ ZEND_BEGIN_MODULE_GLOBALS(v8js)
   char *v8_flags; /* V8 command line flags */
   bool use_date; /* Generate JS Date objects instead of PHP DateTime */
   bool use_array_access; /* Convert ArrayAccess, Countable objects to array-like objects */
+  bool compat_php_exceptions; /* Don't stop JS execution on PHP exception */
 
   // Timer thread globals
   std::deque<v8js_timer_ctx *> timer_stack;

tests/exception_propagation_2.phpt

@@ -14,13 +14,18 @@ class Foo {
 		$this->v8->foo = $this;
 		$this->v8->executeString('fooobar', 'throw_0');
 		var_dump($this->v8->getPendingException());
+		// the exception is not cleared before the next executeString call,
+		// hence the next *exiting* executeString will throw.
+		// In this case this is the executeString call in bar() function.
 		$this->v8->executeString('try { PHP.foo.bar(); } catch (e) { print(e + " caught!\n"); }', 'trycatch1');
 		$this->v8->executeString('try { PHP.foo.bar(); } catch (e) { print(e + " caught!\n"); }', 'trycatch2');
 	}
 
 	public function bar()
 	{
 		echo "To Bar!\n";
+		// This executeString call throws a PHP exception, not propagated
+		// to JS, hence immediately triggering the top-level catch handler.
 		$this->v8->executeString('throw new Error();', 'throw_1');
 	}
 }
@@ -71,7 +76,7 @@ object(V8JsScriptException)#%d (13) {
       ["file"]=>
       string(%d) "%s"
       ["line"]=>
-      int(24)
+      int(29)
       ["function"]=>
       string(11) "__construct"
       ["class"]=>
@@ -100,6 +105,5 @@ object(V8JsScriptException)#%d (13) {
     at throw_0:1:1"
 }
 To Bar!
-Error caught!
 PHP Exception: throw_0:1: ReferenceError: fooobar is not defined
 ===EOF===

tests/issue_156_001.phpt

@@ -0,0 +1,33 @@
+--TEST--
+Test V8::executeString() : Backwards compatibility for issue #156
+--SKIPIF--
+<?php require_once(dirname(__FILE__) . '/skipif.inc'); ?>
+--INI--
+v8js.compat_php_exceptions = 1
+--FILE--
+<?php
+
+$v8 = new V8Js();
+
+$v8->throwPHPException = function () {
+    echo "throwing PHP exception now ...\n";
+    throw new \Exception('foo');
+};
+
+$JS = <<< EOT
+PHP.throwPHPException();
+print("... old behaviour was to not stop JS execution on PHP exceptions\\n");
+EOT;
+
+try {
+    $v8->executeString($JS, 'issue_156_001.js');
+} catch(Exception $e) {
+    var_dump($e->getMessage());
+}
+?>
+===EOF===
+--EXPECT--
+throwing PHP exception now ...
+... old behaviour was to not stop JS execution on PHP exceptions
+string(3) "foo"
+===EOF===

tests/php_exceptions_001.phpt

@@ -0,0 +1,50 @@
+--TEST--
+Test V8::executeString() : PHP Exception handling (repeated)
+--SKIPIF--
+<?php require_once(dirname(__FILE__) . '/skipif.inc'); ?>
+--FILE--
+<?php
+
+class Foo {
+    function throwException() {
+	throw new \Exception("Test-Exception");
+    }
+}
+
+$v8 = new V8Js();
+$v8->foo = new \Foo();
+
+$JS = <<< EOT
+try {
+    PHP.foo.throwException();
+    // the exception should abort further execution,
+    // hence the print must not pop up
+    print("after throwException\\n");
+} catch(e) {
+    // JS should not catch in default mode
+    print("JS caught exception");
+}
+EOT;
+
+for($i = 0; $i < 5; $i ++) {
+    var_dump($i);
+    try {
+        $v8->executeString($JS);
+    } catch (Exception $e) {
+        var_dump($e->getMessage());
+    }
+}
+?>
+===EOF===
+--EXPECTF--
+int(0)
+string(14) "Test-Exception"
+int(1)
+string(14) "Test-Exception"
+int(2)
+string(14) "Test-Exception"
+int(3)
+string(14) "Test-Exception"
+int(4)
+string(14) "Test-Exception"
+===EOF===

tests/php_exceptions_002.phpt

@@ -0,0 +1,67 @@
+--TEST--
+Test V8::executeString() : PHP Exception handling (multi-level)
+--SKIPIF--
+<?php require_once(dirname(__FILE__) . '/skipif.inc'); ?>
+--FILE--
+<?php
+
+class Foo {
+    function throwException() {
+	throw new \Exception("Test-Exception");
+    }
+
+    function recurse($i) {
+        echo "recurse[$i] ...\n";
+        global $work;
+        $work($i);
+    }
+}
+
+$v8 = new V8Js();
+$v8->foo = new \Foo();
+
+$work = $v8->executeString(<<<EOT
+var work = function(level) {
+  if(level--) {
+    PHP.foo.recurse(level);
+  }
+  else {
+    PHP.foo.throwException();
+  }
+};
+work;
+EOT
+);
+
+for($i = 0; $i < 5; $i ++) {
+    var_dump($i);
+    try {
+        $work($i);
+    } catch (Exception $e) {
+        var_dump($e->getMessage());
+    }
+}
+?>
+===EOF===
+--EXPECT--
+int(0)
+string(14) "Test-Exception"
+int(1)
+recurse[0] ...
+string(14) "Test-Exception"
+int(2)
+recurse[1] ...
+recurse[0] ...
+string(14) "Test-Exception"
+int(3)
+recurse[2] ...
+recurse[1] ...
+recurse[0] ...
+string(14) "Test-Exception"
+int(4)
+recurse[3] ...
+recurse[2] ...
+recurse[1] ...
+recurse[0] ...
+string(14) "Test-Exception"
+===EOF===

tests/php_exceptions_003.phpt

@@ -0,0 +1,36 @@
+--TEST--
+Test V8::executeString() : PHP Exception handling (basic JS propagation)
+--SKIPIF--
+<?php require_once(dirname(__FILE__) . '/skipif.inc'); ?>
+--FILE--
+<?php
+
+class Foo {
+    function throwException() {
+	throw new \Exception("Test-Exception");
+    }
+}
+
+$v8 = new V8Js();
+$v8->foo = new \Foo();
+
+$JS = <<< EOT
+try {
+    PHP.foo.throwException();
+    // the exception should abort further execution,
+    // hence the print must not pop up
+    print("after throwException\\n");
+} catch(e) {
+    print("JS caught exception!\\n");
+    var_dump(e.getMessage());
+}
+EOT;
+
+$v8->executeString($JS, 'php_exceptions_003', V8Js::FLAG_PROPAGATE_PHP_EXCEPTIONS);
+
+?>
+===EOF===
+--EXPECTF--
+JS caught exception!
+string(14) "Test-Exception"
+===EOF===

tests/php_exceptions_004.phpt

@@ -0,0 +1,36 @@
+--TEST--
+Test V8::executeString() : PHP Exception handling (PHP->JS->PHP back propagation)
+--SKIPIF--
+<?php require_once(dirname(__FILE__) . '/skipif.inc'); ?>
+--FILE--
+<?php
+
+class Foo {
+    function throwException() {
+	throw new \Exception("Test-Exception");
+    }
+}
+
+$v8 = new V8Js();
+$v8->foo = new \Foo();
+
+$JS = <<< EOT
+PHP.foo.throwException();
+// the exception should abort further execution,
+// hence the print must not pop up
+print("after throwException\\n");
+EOT;
+
+try {
+    $v8->executeString($JS, 'php_exceptions_004', V8Js::FLAG_PROPAGATE_PHP_EXCEPTIONS);
+}
+catch(V8JsScriptException $e) {
+    echo "Got V8JsScriptException\n";
+    var_dump($e->getPrevious()->getMessage());
+}
+?>
+===EOF===
+--EXPECTF--
+Got V8JsScriptException
+string(14) "Test-Exception"
+===EOF===

tests/php_exceptions_005.phpt

@@ -0,0 +1,43 @@
+--TEST--
+Test V8::executeString() : PHP Exception handling (JS throw PHP-exception)
+--SKIPIF--
+<?php require_once(dirname(__FILE__) . '/skipif.inc'); ?>
+--FILE--
+<?php
+
+class Foo {
+    function getException() {
+        return new \Exception("Test-Exception");
+    }
+}
+
+$v8 = new V8Js();
+$v8->foo = new \Foo();
+
+$JS = <<< EOT
+var ex = PHP.foo.getException();
+print("after getException\\n");
+throw ex;
+print("after throw\\n");
+EOT;
+
+try {
+    $v8->executeString($JS, 'php_exceptions_005');
+}
+catch(V8JsScriptException $e) {
+    echo "Got V8JsScriptException\n";
+    var_dump($e->getMessage());
+    var_dump($e->getPrevious()->getMessage());
+}
+?>
+===EOF===
+--EXPECTF--
+after getException
+Got V8JsScriptException
+string(%d) "php_exceptions_005:3: exception 'Exception' with message 'Test-Exception' in %s
+Stack trace:
+#0 [internal function]: Foo->getException()
+#1 %s: V8Js->executeString('var ex = PHP.fo...', 'php_exceptions_...')
+#2 {main}"
+string(14) "Test-Exception"
+===EOF===