Add Dart_PropagateError.

runtime/vm/code_generator.cc

Index: runtime/vm/code_generator.cc
===================================================================
--- runtime/vm/code_generator.cc	(revision 3415)
+++ runtime/vm/code_generator.cc	(working copy)
@@ -431,7 +431,10 @@
     return Code::null();
   } else {
     if (!function.HasCode()) {
-      Compiler::CompileFunction(function);
+      const Error& error = Error::Handle(Compiler::CompileFunction(function));

[siva, 2012/01/31 00:52:34]

Would it make sense to have a version of CompileFunction which calls
Exceptions::PropagateError(error) if an error has occurred?

That way this boiler plate error check code does not have to be repeated every
time.

[turnidge, 2012/01/31 21:56:31]

I sort of find the current version less magical.  The caller has to make a
conscious choice about how to handle the error rather than deciding to call the
"void" CompileFunction in a strange context and not considering how to handle
the error.

Is it okay to leave it like this for now and change it later if it is
problematic?

[siva, 2012/02/01 19:09:38]

Sure.

+      if (!error.IsNull()) {
+        Exceptions::PropagateError(error);
+      }
     }
     functions_cache.AddCompiledFunction(function,
                                         num_arguments,
@@ -443,13 +446,11 @@
 
 // Result of an invoke may be an unhandled exception, in which case we
 // rethrow it.
-static void CheckResultException(const Instance& result) {
-  if (result.IsUnhandledException()) {
-    const UnhandledException& unhandled  = UnhandledException::Handle(
-        reinterpret_cast<RawUnhandledException*>(result.raw()));
-    const Instance& excp = Instance::Handle(unhandled.exception());
-    const Instance& stack = Instance::Handle(unhandled.stacktrace());
-    Exceptions::ReThrow(excp, stack);
+static void CheckResultError(const Object& result) {
+  if (result.IsError()) {
+    Error& error = Error::Handle();
+    error ^= result.raw();
+    Exceptions::PropagateError(error);
   }

[siva, 2012/01/31 00:52:34]

ASSERT(result.IsNull());

[turnidge, 2012/01/31 21:56:31]

Why should the result be null?

[siva, 2012/02/01 19:09:38]

You are right the result does not have to be NULL, I was thinking of the compile
case where it either succeeds or fails, but this is used more for checking the
result of a dart function invocation which can return some other result object

 }
 
@@ -482,7 +483,10 @@
   // further tests.
   const Function& function = Function::CheckedHandle(arguments.At(0));
   if (!function.HasCode()) {
-    Compiler::CompileFunction(function);
+    const Error& error = Error::Handle(Compiler::CompileFunction(function));
+    if (!error.IsNull()) {
+      Exceptions::PropagateError(error);
+    }
   }
 }
 
@@ -707,15 +711,23 @@
   }
   GrowableArray<const Object*> invoke_arguments(0);
   const Array& kNoArgumentNames = Array::Handle();
-  const Instance& result =
-      Instance::Handle(
-          DartEntry::InvokeDynamic(receiver,
-                                   function,
-                                   invoke_arguments,
-                                   kNoArgumentNames));
-  if (result.IsUnhandledException()) {
-    arguments.SetReturn(code);
-    return;  // Error accessing getter, treat as no such method.
+  const Object& result =
+      Object::Handle(DartEntry::InvokeDynamic(receiver,
+                                              function,
+                                              invoke_arguments,
+                                              kNoArgumentNames));
+  if (result.IsError()) {
+    if (result.IsUnhandledException()) {
+      // If the getter throws an exception, treat as no such method.
+      //
+      // TODO(turnidge): Is this the desired behavior?

[siva, 2012/01/31 00:52:34]

Yes this is the desired behaviour.

[turnidge, 2012/01/31 21:56:31]

Thanks.  Updated comment.

+      arguments.SetReturn(code);
+      return;
+    } else {
+      Error& error = Error::Handle();
+      error ^= result.raw();
+      Exceptions::PropagateError(error);
+    }
   }
   if (!result.IsSmi()) {
     const Class& cls = Class::Handle(result.clazz());
@@ -743,7 +755,10 @@
   const Function& function = Function::Handle(closure.function());
   ASSERT(!function.IsNull());
   if (!function.HasCode()) {
-    Compiler::CompileFunction(function);
+    const Error& error = Error::Handle(Compiler::CompileFunction(function));
+    if (!error.IsNull()) {
+      Exceptions::PropagateError(error);
+    }
   }
   const Context& context = Context::Handle(closure.context());
   const Code& code = Code::Handle(function.code());
@@ -792,12 +807,12 @@
   DartEntry::invokestub entrypoint = reinterpret_cast<DartEntry::invokestub>(
       StubCode::InvokeDartCodeEntryPoint());
   ASSERT(context.isolate() == Isolate::Current());
-  const Instance& result = Instance::Handle(
+  const Object& result = Object::Handle(
       entrypoint(instrs.EntryPoint(),
                  adjusted_arg_descriptor,
                  invoke_arguments.data(),
                  context));
-  CheckResultException(result);
+  CheckResultError(result);
   arguments.SetReturn(result);
 }
 
@@ -833,12 +848,12 @@
   GrowableArray<const Object*> invoke_arguments(2);
   invoke_arguments.Add(&original_function_name);
   invoke_arguments.Add(&orig_arguments);
-  const Instance& result = Instance::Handle(
+  const Object& result = Object::Handle(
       DartEntry::InvokeDynamic(receiver,
                                function,
                                invoke_arguments,
                                kNoArgumentNames));
-  CheckResultException(result);
+  CheckResultError(result);
   arguments.SetReturn(result);
 }
 
@@ -915,7 +930,11 @@
     ASSERT(!Code::Handle(function.code()).is_optimized());
     const Code& unoptimized_code = Code::Handle(function.code());
     // Compilation patches the entry of unoptimized code.
-    Compiler::CompileOptimizedFunction(function);
+    const Error& error =
+        Error::Handle(Compiler::CompileOptimizedFunction(function));
+    if (!error.IsNull()) {
+      Exceptions::PropagateError(error);
+    }
     const Code& optimized_code = Code::Handle(function.code());
     ASSERT(!optimized_code.IsNull());
     ASSERT(!unoptimized_code.IsNull());
@@ -1022,7 +1041,10 @@
   if (Code::Handle(function.code()).is_optimized()) {
     // Get unoptimized code. Compilation restores (reenables) the entry of
     // unoptimized code.
-    Compiler::CompileFunction(function);
+    const Error& error = Error::Handle(Compiler::CompileFunction(function));
+    if (!error.IsNull()) {
+      Exceptions::PropagateError(error);
+    }
   }
   // TODO(srdjan): Handle better complex cases, e.g. when an older optimized
   // code is alive on frame and gets deoptimized after the function was