Fix a bug in SSA renaming introduced when using the RemoveFromGraph helper for removing instruction…

vm/flow_graph_builder.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/flow_graph_builder.h"
 
 #include "vm/ast_printer.h"
 #include "vm/bit_vector.h"
 #include "vm/code_descriptors.h"
 #include "vm/dart_entry.h"
@@ skipping 2709 matching lines @@
     if (current->IsDo() &&
         current->AsDo()->computation()->IsStoreLocal()) {
       store = current->AsDo()->computation()->AsStoreLocal();
     } else if (current->IsBind() &&
                current->AsBind()->computation()->IsStoreLocal()) {
       store = current->AsBind()->computation()->AsStoreLocal();
     }
 
     if (load != NULL) {
       // Remove instruction.
-      current->RemoveFromGraph();
+      current = current->RemoveFromGraph();
     } else if (store != NULL) {
       // Remove instruction and update renaming environment.
-      current->RemoveFromGraph();
+      current = current->RemoveFromGraph();
       (*env)[store->local().BitIndexIn(var_count)] = store->value();
-    } else if (current->IsBind()) {
-      // Assign new SSA temporary.
-      current->AsDefinition()->set_ssa_temp_index(current_ssa_temp_index_++);
+    } else {
+      if (current->IsBind()) {
+        // Assign new SSA temporary.
+        current->AsDefinition()->set_ssa_temp_index(current_ssa_temp_index_++);
+      }
+      current = current->successor();
     }
-    current = current->successor();
   }
 
   // 3. Process dominated blocks.
   for (intptr_t i = 0; i < block_entry->dominated_blocks().length(); ++i) {
     BlockEntryInstr* block = block_entry->dominated_blocks()[i];
     ZoneGrowableArray<Value*>* new_env =
         new ZoneGrowableArray<Value*>(var_count);
     new_env->AddArray(*env);
     RenameRecursive(block, new_env, var_count);
   }
@@ skipping 28 matching lines @@
   char* chars = reinterpret_cast<char*>(
       Isolate::Current()->current_zone()->Allocate(len));
   OS::SNPrint(chars, len, kFormat, function_name, reason);
   const Error& error = Error::Handle(
       LanguageError::New(String::Handle(String::New(chars))));
   Isolate::Current()->long_jump_base()->Jump(1, error);
 }
 
 
 }  // namespace dart