Hacky streaming of VariableGet

runtime/vm/kernel_binary_flowgraph.cc

 // Copyright (c) 2016, 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/kernel_binary_flowgraph.h"
 
 #include "vm/object_store.h"
 
 #if !defined(DART_PRECOMPILED_RUNTIME)
 
@@ skipping 196 matching lines @@
 
 
 Fragment StreamingFlowGraphBuilder::BuildAt(intptr_t kernel_offset) {
   SetOffset(kernel_offset);
 
   uint8_t payload = 0;
   Tag tag = ReadTag(&payload);
   switch (tag) {
     case kInvalidExpression:
       return BuildInvalidExpression();
-    //    case kVariableGet:
-    //      return VariableGet::ReadFrom(reader_);
-    //    case kSpecializedVariableGet:
-    //      return VariableGet::ReadFrom(reader_, payload);
+    case kVariableGet:
+      return BuildVariableGet();
+    case kSpecializedVariableGet:
+      return BuildVariableGet(payload);
     //    case kVariableSet:
     //      return VariableSet::ReadFrom(reader_);
     //    case kSpecializedVariableSet:
     //      return VariableSet::ReadFrom(reader_, payload);
     //    case kPropertyGet:
     //      return PropertyGet::ReadFrom(reader_);
     //    case kPropertySet:
     //      return PropertySet::ReadFrom(reader_);
     //    case kDirectPropertyGet:
     //      return DirectPropertyGet::ReadFrom(reader_);
@@ skipping 245 matching lines @@
   intptr_t savedOffset = ReaderOffset();
 
   SetOffset(GetStringTableOffset(str_index));
   uint32_t bytes = ReadUInt();
   const uint8_t* data = &reader_->buffer()[ReaderOffset()];
 
   SetOffset(savedOffset);
   return new String(data, bytes);
 }
 
+dart::LocalVariable* StreamingFlowGraphBuilder::LookupVariable(
+    intptr_t kernel_offset) {
+  return flow_graph_builder_->LookupVariable(kernel_offset);
+}
+
 Fragment StreamingFlowGraphBuilder::DebugStepCheck(TokenPosition position) {
   return flow_graph_builder_->DebugStepCheck(position);
 }
 
 Fragment StreamingFlowGraphBuilder::LoadLocal(LocalVariable* variable) {
   return flow_graph_builder_->LoadLocal(variable);
 }
 
 Fragment StreamingFlowGraphBuilder::PushArgument() {
   return flow_graph_builder_->PushArgument();
@@ skipping 26 matching lines @@
   return flow_graph_builder_->StaticCall(position, target, argument_count);
 }
 
 Fragment StreamingFlowGraphBuilder::BuildInvalidExpression() {
   // The frontend will take care of emitting normal errors (like
   // [NoSuchMethodError]s) and only emit [InvalidExpression]s in very special
   // situations (e.g. an invalid annotation).
   return ThrowNoSuchMethodError();
 }
 
+Fragment StreamingFlowGraphBuilder::BuildVariableGet() {
+  ReadPosition();
+  intptr_t variable_kernel_position = ReadUInt();
+  ReadUInt();  // Variable index.
+
+  // TODO(jensj): This is actually a "reader->ReadOptional<DartType>();".
+  // Optional type below: Not currently implemented.
+  Tag tag = ReadTag();
+  if (tag != kNothing) {
+    UNIMPLEMENTED();
+  }
+
+  return LoadLocal(LookupVariable(variable_kernel_position));
+}
+
+Fragment StreamingFlowGraphBuilder::BuildVariableGet(uint8_t payload) {
+  ReadPosition();
+  intptr_t variable_kernel_position = ReadUInt();
+  return LoadLocal(LookupVariable(variable_kernel_position));
+}
+
 Fragment StreamingFlowGraphBuilder::BuildStaticGet() {
   intptr_t saved_offset = ReaderOffset() - 1;  // Include the tag.
   TokenPosition position = ReadPosition();
   int canonical_name_index = ReadUInt();
   CanonicalName* target = GetCanonicalName(canonical_name_index);
 
   if (target->IsField()) {
     const dart::Field& field =
         dart::Field::ZoneHandle(Z, H.LookupFieldByKernelField(target));
     if (field.is_const()) {
@@ skipping 79 matching lines @@
 }
 
 Fragment StreamingFlowGraphBuilder::BuildNullLiteral() {
   return Constant(Instance::ZoneHandle(Z, Instance::null()));
 }
 
 }  // namespace kernel
 }  // namespace dart
 
 #endif  // !defined(DART_PRECOMPILED_RUNTIME)