dart2js: Allow 'throw' when inlining

sdk/lib/_internal/compiler/implementation/lib/js_helper.dart

Index: sdk/lib/_internal/compiler/implementation/lib/js_helper.dart
diff --git a/sdk/lib/_internal/compiler/implementation/lib/js_helper.dart b/sdk/lib/_internal/compiler/implementation/lib/js_helper.dart
index badbb4dd1186584f34d1bf51708783def14f5ac9..781d1c101c0093b8a2d9efd378ff87093b76d80e 100644
--- a/sdk/lib/_internal/compiler/implementation/lib/js_helper.dart
+++ b/sdk/lib/_internal/compiler/implementation/lib/js_helper.dart
@@ -614,7 +614,7 @@ checkString(value) {
  * The code in [unwrapException] deals with getting the original Dart
  * object out of the wrapper again.
  */
-$throw(ex) {
+wrapException(ex) {
   if (ex == null) ex = const NullThrownError();
   var wrapper = new DartError(ex);
 
@@ -622,7 +622,7 @@ $throw(ex) {
     // Use V8 API for recording a "fast" stack trace (this installs a
     // "stack" property getter on [wrapper]).
     JS('void', r'Error.captureStackTrace(#, #)',
-       wrapper, RAW_DART_FUNCTION_REF($throw));
+       wrapper, RAW_DART_FUNCTION_REF(wrapException));
   } else {
     // Otherwise, produce a stack trace and record it in the wrapper.
     // This is a slower way to create a stack trace which works on
@@ -634,6 +634,16 @@ $throw(ex) {
 }
 
 /**
+ * This wraos the exception and actually does the throw too.  It is

[ngeoffray, 2013/04/11 09:31:08]

wraos -> wraps

[ngeoffray, 2013/04/11 09:31:08]

actually does the throw too -> does the throw

+ * possible to call this in a JS expression context, where the throw statement
+ * is not allowed.  Helpers are never inlined, so we don't risk inlining the
+ * throw statement into an expression context.
+ */
+throwExpression(ex) {
+  JS('void', 'throw #', wrapException(ex));
+}
+
+/**
  * Wrapper class for throwing exceptions.
  */
 class DartError {
@@ -652,8 +662,8 @@ class DartError {
 
   /**
    * V8/Chrome installs a property getter, "stack", when calling
-   * Error.captureStackTrace (see [$throw]). In [$throw], we make sure
-   * that this property is always set.
+   * Error.captureStackTrace (see [wrapException]). In [wrapException], we make
+   * sure that this property is always set.
    */
   String get stack => JS('', '#.stack', this);
 
@@ -663,7 +673,7 @@ class DartError {
    *
    * We only expect this method to be called (indirectly) by the
    * browser when an uncaught exception occurs. Instance of this class
-   * should never escape into Dart code (except for [$throw] above).
+   * should never escape into Dart code (except for [wrapException] above).
    */
   String toString() {
     // If Error.captureStackTrace is available, accessing stack from
@@ -715,7 +725,7 @@ throwAbstractClassInstantiationError(className) {
 /**
  * Called from catch blocks in generated code to extract the Dart
  * exception from the thrown value. The thrown value may have been
- * created by [$throw] or it may be a 'native' JS exception.
+ * created by [wrapException] or it may be a 'native' JS exception.
  *
  * Some native exceptions are mapped to new Dart instances, others are
  * returned unmodified.