Initial steps into streaming the kernel flowgraph

runtime/vm/kernel_binary_flowgraph.h

+// Copyright (c) 2017, 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.
+
+#ifndef RUNTIME_VM_KERNEL_BINARY_FLOWGRAPH_H_
+#define RUNTIME_VM_KERNEL_BINARY_FLOWGRAPH_H_
+
+#if !defined(DART_PRECOMPILED_RUNTIME)
+
+#include <map>
+
+#include "vm/kernel.h"
+#include "vm/kernel_binary.h"
+#include "vm/kernel_to_il.h"
+#include "vm/object.h"
+
+namespace dart {
+namespace kernel {
+
+class StreamingFlowGraphBuilder {
+ public:
+  StreamingFlowGraphBuilder(FlowGraphBuilder* flowGraph_builder,
+                            const uint8_t* buffer,
+                            intptr_t buffer_length)
+      : flow_graph_builder_(flowGraph_builder),
+        reader_(new kernel::Reader(buffer, buffer_length)) {}
+
+  virtual ~StreamingFlowGraphBuilder() { delete reader_; }
+
+  Fragment BuildAt(intptr_t kernel_offset);
+
+ private:
+  TokenPosition ReadPosition(bool record = true);
+
+  CatchBlock* catch_block();
+
+  Fragment DebugStepCheck(TokenPosition position);
+  Fragment LoadLocal(LocalVariable* variable);
+  Fragment PushArgument();
+  Fragment RethrowException(TokenPosition position, int catch_try_index);
+
+  Fragment BuildRethrow();
+
+  FlowGraphBuilder* flow_graph_builder_;
+  kernel::Reader* reader_;
+};
+
+}  // namespace kernel
+}  // namespace dart
+
+#endif  // !defined(DART_PRECOMPILED_RUNTIME)
+#endif  // RUNTIME_VM_KERNEL_BINARY_FLOWGRAPH_H_