cps-ir: Support foreign code.

pkg/compiler/lib/src/js_backend/codegen/task.dart

Index: pkg/compiler/lib/src/js_backend/codegen/task.dart
diff --git a/pkg/compiler/lib/src/js_backend/codegen/task.dart b/pkg/compiler/lib/src/js_backend/codegen/task.dart
index 01ec7a2282dcc15979263b85712b90da1b53f817..78b9d32d884d85d58522c6ee8aced2b34e3b70b2 100644
--- a/pkg/compiler/lib/src/js_backend/codegen/task.dart
+++ b/pkg/compiler/lib/src/js_backend/codegen/task.dart
@@ -57,20 +57,35 @@ class CpsFunctionCompiler implements FunctionCompiler {
 
   String get name => 'CPS Ir pipeline';
 
-  /// Generates JavaScript code for `work.element`. First tries to use the
-  /// Cps Ir -> tree ir -> js pipeline, and if that fails due to language
-  /// features not implemented it will fall back to the ssa pipeline (for
-  /// platform code) or will cancel compilation (for user code).
+  /// Generates JavaScript code for `work.element`.
   js.Fun compile(CodegenWorkItem work) {
     AstElement element = work.element;
     JavaScriptBackend backend = compiler.backend;
     return compiler.withCurrentElement(element, () {
-      if (element.library.isPlatformLibrary ||
-          element.library == backend.interceptorsLibrary) {
-        compiler.log('Using SSA compiler for platform element $element');
-        return fallbackCompiler.compile(work);
-      }
       try {
+        ClassElement cls = element.enclosingClass;
+        String name = element.name;
+        String className = cls == null ? null : cls.name;
+        LibraryElement library = element.library;
+        String libraryName = library == null ? null : library.toString();
+        // TODO(karlklose): remove this fallback.
+        // Fallback for a few functions that we know require try-finally and
+        // switch.
+        if (element.isNative ||
+            libraryName == 'origin library(dart:typed_data)' ||
+            // switch
+            library.isInternalLibrary && name == 'unwrapException' ||
+            // try-finally
+            library.isPlatformLibrary && className == 'IterableBase' ||
+            library.isInternalLibrary && className == 'Closure' ||
+
+            libraryName == 'origin library(dart:collection)' &&
+               name == 'mapToString' ||
+            libraryName == 'library(dart:html)' && name == 'sanitizeNode') {
+          compiler.log('Using SSA compiler for platform element $element');
+          return fallbackCompiler.compile(work);
+        }
+
         if (tracer != null) {
           tracer.traceCompilation(element.name, null);
         }