Minor Native Client specific changes to files in src.

src/platform-linux.cc

Index: src/platform-linux.cc
diff --git a/src/platform-linux.cc b/src/platform-linux.cc
index 1f9cde151c13f554a108a4b90b74573187808cdd..701843a646d8622ea68db8bb2624cdc8138fe40f 100644
--- a/src/platform-linux.cc
+++ b/src/platform-linux.cc
@@ -428,6 +428,8 @@ void OS::DebugBreak() {
 # endif
 #elif defined(__mips__)
   asm("break");
+#elif defined(__native_client__)
+  asm("hlt");
 #else
   asm("int $3");
 #endif
@@ -822,12 +824,16 @@ void Thread::set_name(const char* name) {
 
 void Thread::Start() {
   pthread_attr_t* attr_ptr = NULL;
+#if defined(__native_client__)
+  // use default stack size.
+#else
   pthread_attr_t attr;
   if (stack_size_ > 0) {
     pthread_attr_init(&attr);
     pthread_attr_setstacksize(&attr, static_cast<size_t>(stack_size_));
     attr_ptr = &attr;
   }
+#endif
   int result = pthread_create(&data_->thread_, attr_ptr, ThreadEntry, this);
   CHECK_EQ(0, result);
   ASSERT(data_->thread_ != kNoThread);
@@ -1074,6 +1080,10 @@ static int GetThreadID() {
 
 
 static void ProfilerSignalHandler(int signal, siginfo_t* info, void* context) {
+#if defined(__native_client__) && defined(__x86_64__)
+  // Profiling is disabled for x86_64 Native Client.

[ulan, 2013/04/08 11:27:10]

Is this #ifdef needed because of undefined ucontext_t compile errors on
nacl_x64? It might be better to define ucontext_t as we do above for ANDROID.

[Brad Chen, 2013/04/08 16:29:56]

No, in this case the problem is more fundamental, that Native Client doesnt'
support exception handling, which appears to be required for profiling support.
I will improve the comment.

[Brad Chen, 2013/04/08 16:38:32]

It might be possible to get this code to compile using the approach used with
ANDROID, but because of the signal handling issues it would not run. I will
change the #ifdef to disable for Native Client on all platforms. Okay?

+  return;
+#else
   USE(info);
   if (signal != SIGPROF) return;
   Isolate* isolate = Isolate::UncheckedCurrent();
@@ -1126,6 +1136,7 @@ static void ProfilerSignalHandler(int signal, siginfo_t* info, void* context) {
 #endif  // V8_HOST_ARCH_*
   sampler->SampleStack(sample);
   sampler->Tick(sample);
+#endif  // __native_client__ && __x86_64__
 }