Implements features to run "Hello, world!" on simulated MIPS.

runtime/vm/assembler_mips.cc

 // Copyright (c) 2013, 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/globals.h"
 #if defined(TARGET_ARCH_MIPS)
 
 #include "vm/assembler.h"
 #include "vm/runtime_entry.h"
 #include "vm/simulator.h"
 #include "vm/stub_code.h"
 
 namespace dart {
 
+DECLARE_FLAG(bool, trace_sim);
 DEFINE_FLAG(bool, print_stop_message, false, "Print stop message.");
 
 
 void Assembler::InitializeMemoryWithBreakpoints(uword data, int length) {
   ASSERT(Utils::IsAligned(data, 4));
   ASSERT(Utils::IsAligned(length, 4));
   const uword end = data + length;
   while (data < end) {
     *reinterpret_cast<int32_t*>(data) = Instr::kBreakPointInstruction;
     data += 4;
@@ skipping 511 matching lines @@
   if (FLAG_print_stop_message) {
     UNIMPLEMENTED();
   }
   Label stop;
   b(&stop);
   Emit(reinterpret_cast<int32_t>(message));
   Bind(&stop);
   break_(Instr::kStopMessageCode);
 }
 
+
+void Assembler::TraceSimMsg(const char* message) {
+  //  Don't bother adding in the messages unless tracing is enabled.
+  if (FLAG_trace_sim) {
+    Label msg;
+    b(&msg);
+    Emit(reinterpret_cast<int32_t>(message));
+    Bind(&msg);
+    break_(Instr::kMsgMessageCode);
+  }
+}
+
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_MIPS