Remove unreachable exits from the list collected by InlineExitCollector.

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 "platform/assert.h"
 #include "platform/globals.h"
 #include "vm/allocation.h"
@@ skipping 24 matching lines @@
   InlineExitCollector(FlowGraph* caller_graph, Definition* call)
       : caller_graph_(caller_graph), call_(call), exits_(4) { }
 
   void AddExit(ReturnInstr* exit);
 
   void Union(const InlineExitCollector* other);
 
   // Before replacing a call with a graph, the outer environment needs to be
   // attached to each instruction in the callee graph and the caller graph
   // needs to have its block and instruction ID state updated.
+  // Additionally we need to remove all unreachable exits from the list of
+  // collected exits.
   void PrepareGraphs(FlowGraph* callee_graph);
 
   // Inline a graph at a call site.
   //
   // Assumes the callee is in SSA with a correct dominator tree and use
   // lists.
   //
   // After inlining the caller graph will have correctly adjusted the use
   // lists.  The block orders will need to be recomputed.
   void ReplaceCall(TargetEntryInstr* callee_entry);
@@ skipping 16 matching lines @@
   Value* ValueAt(intptr_t i) const {
     return ReturnAt(i)->value();
   }
 
   ReturnInstr* ReturnAt(intptr_t i) const {
     return exits_[i].exit_return;
   }
 
   static int LowestBlockIdFirst(const Data* a, const Data* b);
   void SortExits();
+  void RemoveUnreachableExits(FlowGraph* callee_graph);
 
   Definition* JoinReturns(BlockEntryInstr** exit_block,
                           Instruction** last_instruction,
                           intptr_t try_index);
 
   Isolate* isolate() const { return caller_graph_->isolate(); }
   Zone* zone() const { return caller_graph_->zone(); }
 
   FlowGraph* caller_graph_;
   Definition* call_;
@@ skipping 485 matching lines @@
   // Output parameters.
   GrowableArray<TargetEntryInstr**> true_successor_addresses_;
   GrowableArray<TargetEntryInstr**> false_successor_addresses_;
 
   intptr_t condition_token_pos_;
 };
 
 }  // namespace dart
 
 #endif  // VM_FLOW_GRAPH_BUILDER_H_