null value can be the receiver of methods on Object (e.g. hashCode).

runtime/vm/compiler.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/compiler.h"
 
 #include "vm/assembler.h"
 
 #include "vm/ast_printer.h"
 #include "vm/code_generator.h"
@@ skipping 94 matching lines @@
               Code::Handle(function.CurrentCode()).EntryPoint());
   }
   function.SwitchToUnoptimizedCode();
   if (FLAG_trace_compiler) {
     OS::Print("--> restoring entry at %#"Px"\n",
               Code::Handle(function.unoptimized_code()).EntryPoint());
   }
 }
 
 
-static void PrintGraph(const char* phase, FlowGraph* flow_graph) {
-  OS::Print("*** BEGIN CFG\n%s\n", phase);
-  FlowGraphPrinter printer(*flow_graph);
-  printer.PrintBlocks();
-  OS::Print("*** END CFG\n");
-}
-
-
 // Return false if bailed out.
 static bool CompileParsedFunctionHelper(const ParsedFunction& parsed_function,
                                         bool optimized) {
   TimerScope timer(FLAG_compiler_stats, &CompilerStats::codegen_timer);
   bool is_compiled = false;
   Isolate* isolate = Isolate::Current();
   HANDLESCOPE(isolate);
   ASSERT(isolate->ic_data_array() == Array::null());  // Must be reset to null.
   const intptr_t prev_deopt_id = isolate->deopt_id();
   isolate->set_deopt_id(0);
@@ skipping 32 matching lines @@
       TimerScope timer(FLAG_compiler_stats,
                        &CompilerStats::ssa_timer,
                        isolate);
       // Transform to SSA (virtual register 0 and no inlining arguments).
       flow_graph->ComputeSSA(0, NULL);
       DEBUG_ASSERT(flow_graph->VerifyUseLists());
     }
 
     if (FLAG_print_flow_graph ||
         (optimized && FLAG_print_flow_graph_optimized)) {
-      PrintGraph("Before Optimizations", flow_graph);
+      FlowGraphPrinter::PrintGraph("Before Optimizations", flow_graph);
     }
 
     if (optimized) {
       TimerScope timer(FLAG_compiler_stats,
                        &CompilerStats::graphoptimizer_timer,
                        isolate);
 
       FlowGraphOptimizer optimizer(flow_graph);
       optimizer.ApplyICData();
       DEBUG_ASSERT(flow_graph->VerifyUseLists());
@@ skipping 70 matching lines @@
 
       // The final canonicalization pass before the code generation.
       optimizer.Canonicalize();
       DEBUG_ASSERT(flow_graph->VerifyUseLists());
 
       // Perform register allocation on the SSA graph.
       FlowGraphAllocator allocator(*flow_graph);
       allocator.AllocateRegisters();
 
       if (FLAG_print_flow_graph || FLAG_print_flow_graph_optimized) {
-        PrintGraph("After Optimizations", flow_graph);
+        FlowGraphPrinter::PrintGraph("After Optimizations", flow_graph);
       }
     }
 
     Assembler assembler;
     FlowGraphCompiler graph_compiler(&assembler,
                                      *flow_graph,
                                      optimized);
     {
       TimerScope timer(FLAG_compiler_stats,
                        &CompilerStats::graphcompiler_timer,
@@ skipping 377 matching lines @@
       Object::Handle(isolate->object_store()->sticky_error());
     isolate->object_store()->clear_sticky_error();
     isolate->set_long_jump_base(base);
     return result.raw();
   }
   UNREACHABLE();
   return Object::null();
 }
 
 }  // namespace dart