RemoveFromGraph on definitions asserts empty use lists.

runtime/vm/intermediate_language.cc

 // 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.
 
 #include "vm/intermediate_language.h"
 
 #include "vm/bit_vector.h"
 #include "vm/dart_entry.h"
 #include "vm/flow_graph_allocator.h"
 #include "vm/flow_graph_builder.h"
@@ skipping 124 matching lines @@
   prev_instr->set_next(next_instr);
   next_instr->set_previous(prev_instr);
   // Reset successor and previous instruction to indicate
   // that the instruction is removed from the graph.
   set_previous(NULL);
   set_next(NULL);
   return return_previous ? prev_instr : next_instr;
 }
 
 
+Instruction* Definition::RemoveFromGraph(bool return_previous) {
+  ASSERT(use_list() == NULL);

[Florian Schneider, 2012/08/13 08:37:37]

Alternatively, you could put the assert in Instruction::RemoveFromGraph to avoid
overriding just for the assertion:

ASSERT(AsDefinition() == NULL || AsDefinition()->use_list() == NULL);

+  return Instruction::RemoveFromGraph(return_previous);
+}
+
+
 void ForwardInstructionIterator::RemoveCurrentFromGraph() {
   current_ = current_->RemoveFromGraph(true);  // Set current_ to previous.
 }
 
 
 // Default implementation of visiting basic blocks.  Can be overridden.
 void FlowGraphVisitor::VisitBlocks() {
   for (intptr_t i = 0; i < block_order_.length(); ++i) {
     BlockEntryInstr* entry = block_order_[i];
     entry->Accept(this);
@@ skipping 1092 matching lines @@
   if (compiler->is_ssa()) {
     ASSERT(locs()->in(0).IsRegister());
     __ PushRegister(locs()->in(0).reg());
   }
 }
 
 
 #undef __
 
 }  // namespace dart