Add Dart_PropagateError.

runtime/vm/code_generator.cc

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/code_generator.h"
 
 #include "vm/code_index_table.h"
 #include "vm/code_patcher.h"
 #include "vm/compiler.h"
 #include "vm/dart_api_impl.h"
@@ skipping 413 matching lines @@
 
   Function& function = Function::Handle();
   function = Resolver::ResolveDynamic(receiver,
                                       function_name,
                                       num_arguments,
                                       num_named_arguments);
   if (function.IsNull()) {
     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,
                                         num_named_arguments);
     return function.code();
   }
 }
 
 
 // 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

 }
 
 
 // Resolves an instance function and compiles it if necessary.
 //   Arg0: receiver object.
 //   Returns: RawCode object or NULL (method not found or not compileable).
 // This is called by the megamorphic stub when instance call does not need to be
 // patched.
 // Used by megamorphic lookup/no-such-method-handling.
 DEFINE_RUNTIME_ENTRY(ResolveCompileInstanceFunction, 1) {
@@ skipping 11 matching lines @@
 DEFINE_RUNTIME_ENTRY(BreakpointStaticHandler, 1) {
   ASSERT(arguments.Count() ==
       kBreakpointStaticHandlerRuntimeEntry.argument_count());
   ASSERT(isolate->debugger() != NULL);
   isolate->debugger()->BreakpointCallback();
   // Make sure the static function that is about to be called is
   // compiled. The stub will jump to the entry point without any
   // 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);
+    }
   }
 }
 
 
 // Gets called from debug stub when code reaches a breakpoint.
 DEFINE_RUNTIME_ENTRY(BreakpointDynamicHandler, 0) {
   ASSERT(arguments.Count() ==
      kBreakpointDynamicHandlerRuntimeEntry.argument_count());
   ASSERT(isolate->debugger() != NULL);
   isolate->debugger()->BreakpointCallback();
@@ skipping 204 matching lines @@
                                getter_function_name,
                                kNumArguments,
                                kNumNamedArguments));
   Code& code = Code::Handle();
   if (function.IsNull()) {
     arguments.SetReturn(code);
     return;  // No getter function found so can't be an implicit closure.
   }
   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());
     ASSERT(!cls.IsNull());
     function = cls.signature_function();
     if (!function.IsNull()) {
       arguments.SetReturn(result);
       return;  // Return closure object.
     }
   }
   Exceptions::ThrowByType(Exceptions::kObjectNotClosure, invoke_arguments);
 }
 
 
 // Invoke Implicit Closure function.
 // Arg0: closure object.
 // Arg1: arguments descriptor (originally passed as dart instance invocation).
 // Arg2: arguments array (originally passed to dart instance invocation).
 DEFINE_RUNTIME_ENTRY(InvokeImplicitClosureFunction, 3) {
   ASSERT(arguments.Count() ==
          kInvokeImplicitClosureFunctionRuntimeEntry.argument_count());
   const Closure& closure = Closure::CheckedHandle(arguments.At(0));
   const Array& arg_descriptor = Array::CheckedHandle(arguments.At(1));
   const Array& func_arguments = Array::CheckedHandle(arguments.At(2));
   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());
   ASSERT(!code.IsNull());
   const Instructions& instrs = Instructions::Handle(code.instructions());
   ASSERT(!instrs.IsNull());
 
   // Adjust arguments descriptor array to account for removal of the receiver
   // parameter. Since the arguments descriptor array is canonicalized, create a
   // new one instead of patching the original one.
@@ skipping 28 matching lines @@
   GrowableArray<const Object*> invoke_arguments(0);
   for (intptr_t i = 0; i < func_arguments.Length(); i++) {
     const Object& value = Object::Handle(func_arguments.At(i));
     invoke_arguments.Add(&value);
   }
 
   // Now Call the invoke stub which will invoke the closure.
   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);
 }
 
 
 // Invoke appropriate noSuchMethod function.
 // Arg0: receiver.
 // Arg1: ic-data array.
 // Arg2: original arguments descriptor array.
 // Arg3: original arguments array.
 DEFINE_RUNTIME_ENTRY(InvokeNoSuchMethodFunction, 4) {
@@ skipping 15 matching lines @@
       String::Handle(String::NewSymbol("noSuchMethod"));
   const Function& function = Function::ZoneHandle(
       Resolver::ResolveDynamic(receiver,
                                function_name,
                                kNumArguments,
                                kNumNamedArguments));
   ASSERT(!function.IsNull());
   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);
 }
 
 
 // Report that an object is not a closure.
 // Arg0: non-closure object.
 // Arg1: arguments array.
 DEFINE_RUNTIME_ENTRY(ReportObjectNotClosure, 2) {
   ASSERT(arguments.Count() ==
          kReportObjectNotClosureRuntimeEntry.argument_count());
@@ skipping 56 matching lines @@
   if (function.deoptimization_counter() >=
       FLAG_deoptimization_counter_threshold) {
     // TODO(srdjan): Investigate excessive deoptimization.
     function.set_invocation_counter(0);
     return;
   }
   if (function.is_optimizable()) {
     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());
   } else {
     // TODO(5442338): Abort as this should not happen.
     function.set_invocation_counter(0);
   }
 }
 
 
@@ skipping 86 matching lines @@
   // types/classes have been collected.
   function.set_invocation_counter(0);
   function.set_deoptimization_counter(function.deoptimization_counter() + 1);
 
   // We have to skip the following otherwise the compiler will complain
   // when it attempts to install unoptimized code into a function that
   // was already deoptimized.
   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
   // optimized a second time.
   if (FLAG_trace_deopt) {
     OS::Print("After patching ->0x%x:\n", continue_at_pc);
   }
 }
 
 
@@ skipping 70 matching lines @@
       }
     }
   }
   // The cache is null terminated, therefore the loop above should never
   // terminate by itself.
   UNREACHABLE();
   return Code::null();
 }
 
 }  // namespace dart