Try/catch in graph builder.

runtime/vm/flow_graph_builder.h

 // Copyright (c) 2012, 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 VM_FLOW_GRAPH_BUILDER_H_
 #define VM_FLOW_GRAPH_BUILDER_H_
 
 #include "vm/allocation.h"
 #include "vm/ast.h"
 #include "vm/growable_array.h"
 #include "vm/intermediate_language.h"
 
 namespace dart {
 
 class Instruction;
 class ParsedFunction;
 
 // Build a flow graph from a parsed function's AST.
 class FlowGraphBuilder: public ValueObject {
  public:
-  explicit FlowGraphBuilder(const ParsedFunction& parsed_function)
-      : parsed_function_(parsed_function),
-        preorder_block_entries_(),
-        postorder_block_entries_(),
-        context_level_(0) { }
+  explicit FlowGraphBuilder(const ParsedFunction& parsed_function);
 
   void BuildGraph();
 
   const ParsedFunction& parsed_function() const { return parsed_function_; }
 
   const GrowableArray<BlockEntryInstr*>& postorder_block_entries() const {
     return postorder_block_entries_;
   }
 
   void Bailout(const char* reason);
 
   void set_context_level(intptr_t value) { context_level_ = value; }
   intptr_t context_level() const { return context_level_; }
 
+  // Each try in this function gets its own try index.
+  intptr_t AllocateTryIndex() { return ++last_used_try_index_; }
+
+  // Manage the currently active try index.
+  void set_try_index(intptr_t value) { try_index_ = value; }
+  intptr_t try_index() const { return try_index_; }
+
+  void AddCatchEntry(intptr_t try_index, Instruction* entry);
+
  private:
   void ComputeDominators(GrowableArray<BlockEntryInstr*>* preorder,
                          GrowableArray<intptr_t>* parent);
   void CompressPath(intptr_t start_index,
                     intptr_t current_index,
                     GrowableArray<intptr_t>* parent,
                     GrowableArray<intptr_t>* label);
 
   const ParsedFunction& parsed_function_;
   GrowableArray<BlockEntryInstr*> preorder_block_entries_;
   GrowableArray<BlockEntryInstr*> postorder_block_entries_;
   intptr_t context_level_;
+  intptr_t last_used_try_index_;
+  intptr_t try_index_;
+  GrowableArray<Instruction*> catch_entries_;
+
+  DISALLOW_IMPLICIT_CONSTRUCTORS(FlowGraphBuilder);
 };
 
 
 class TestGraphVisitor;
 
 // Translate an AstNode to a control-flow graph fragment for its effects
 // (e.g., a statement or an expression in an effect context).  Implements a
 // function from an AstNode and next temporary index to a graph fragment
 // with a single entry and at most one exit.  The fragment is represented by
 // an (entry, exit) pair of Instruction pointers:
@@ skipping 94 matching lines @@
 
   virtual void CompiletimeStringInterpolation(const Function& interpol_func,
                                               const Array& literals);
 
   TempVal* BuildObjectAllocation(ConstructorCallNode* node,
                                  int start_index);
   void BuildConstructorCall(ConstructorCallNode* node,
                             int start_index,
                             Value* alloc_value);
 
+  void BuildStoreContext(const LocalVariable& variable, intptr_t start_index);
+  void BuildLoadContext(const LocalVariable& variable, intptr_t start_index);
+
   void BuildThrowNode(ThrowNode* node);
 
  private:
   // Specify a computation as the final result.  Adds a Do instruction to
   // the graph, but normally overridden in subclasses.
   virtual void ReturnComputation(Computation* computation) {
     AddInstruction(new DoInstr(computation));
   }
 
   // Shared global state.
@@ skipping 116 matching lines @@
   }
 
   // Output parameters.
   TargetEntryInstr** true_successor_address_;
   TargetEntryInstr** false_successor_address_;
 };
 
 }  // namespace dart
 
 #endif  // VM_FLOW_GRAPH_BUILDER_H_