Synchronize with r15701.

src/platform-linux.cc

Index: src/platform-linux.cc
diff --git a/src/platform-linux.cc b/src/platform-linux.cc
index 5008eeb5b3ef932170d2c1668026d28a7458f36d..a9aaf7803b8dd2e2295057146447c69d6cda764d 100644
--- a/src/platform-linux.cc
+++ b/src/platform-linux.cc
@@ -146,6 +146,9 @@ bool OS::ArmCpuHasFeature(CpuFeature feature) {
     case VFP3:
       search_string = "vfpv3";
       break;
+    case NEON:
+      search_string = "neon";
+      break;
     case ARMv7:
       search_string = "ARMv7";
       break;
@@ -200,6 +203,36 @@ CpuImplementer OS::GetCpuImplementer() {
 }
 
 
+CpuPart OS::GetCpuPart(CpuImplementer implementer) {
+  static bool use_cached_value = false;
+  static CpuPart cached_value = CPU_UNKNOWN;
+  if (use_cached_value) {
+    return cached_value;
+  }
+  if (implementer == ARM_IMPLEMENTER) {
+    if (CPUInfoContainsString("CPU part\t: 0xc0f")) {
+      cached_value = CORTEX_A15;
+    } else if (CPUInfoContainsString("CPU part\t: 0xc0c")) {
+      cached_value = CORTEX_A12;
+    } else if (CPUInfoContainsString("CPU part\t: 0xc09")) {
+      cached_value = CORTEX_A9;
+    } else if (CPUInfoContainsString("CPU part\t: 0xc08")) {
+      cached_value = CORTEX_A8;
+    } else if (CPUInfoContainsString("CPU part\t: 0xc07")) {
+      cached_value = CORTEX_A7;
+    } else if (CPUInfoContainsString("CPU part\t: 0xc05")) {
+      cached_value = CORTEX_A5;
+    } else {
+      cached_value = CPU_UNKNOWN;
+    }
+  } else {
+    cached_value = CPU_UNKNOWN;
+  }
+  use_cached_value = true;
+  return cached_value;
+}
+
+
 bool OS::ArmUsingHardFloat() {
   // GCC versions 4.6 and above define __ARM_PCS or __ARM_PCS_VFP to specify
   // the Floating Point ABI used (PCS stands for Procedure Call Standard).
@@ -420,32 +453,9 @@ void OS::DebugBreak() {
 
 
 void OS::DumpBacktrace() {
+  // backtrace is a glibc extension.
 #if defined(__GLIBC__) && !defined(__UCLIBC__)
-  void* trace[100];
-  int size = backtrace(trace, ARRAY_SIZE(trace));
-  char** symbols = backtrace_symbols(trace, size);
-  fprintf(stderr, "\n==== C stack trace ===============================\n\n");
-  if (size == 0) {
-    fprintf(stderr, "(empty)\n");
-  } else if (symbols == NULL) {
-    fprintf(stderr, "(no symbols)\n");
-  } else {
-    for (int i = 1; i < size; ++i) {
-      fprintf(stderr, "%2d: ", i);
-      char mangled[201];
-      if (sscanf(symbols[i], "%*[^(]%*[(]%200[^)+]", mangled) == 1) {  // NOLINT
-        int status;
-        size_t length;
-        char* demangled = abi::__cxa_demangle(mangled, NULL, &length, &status);
-        fprintf(stderr, "%s\n", demangled ? demangled : mangled);
-        free(demangled);
-      } else {
-        fprintf(stderr, "??\n");
-      }
-    }
-  }
-  fflush(stderr);
-  free(symbols);
+  POSIXBacktraceHelper<backtrace, backtrace_symbols>::DumpBacktrace();
 #endif
 }
 
@@ -599,33 +609,10 @@ void OS::SignalCodeMovingGC() {
 int OS::StackWalk(Vector<OS::StackFrame> frames) {
   // backtrace is a glibc extension.
 #if defined(__GLIBC__) && !defined(__UCLIBC__)
-  int frames_size = frames.length();
-  ScopedVector<void*> addresses(frames_size);
-
-  int frames_count = backtrace(addresses.start(), frames_size);
-
-  char** symbols = backtrace_symbols(addresses.start(), frames_count);
-  if (symbols == NULL) {
-    return kStackWalkError;
-  }
-
-  for (int i = 0; i < frames_count; i++) {
-    frames[i].address = addresses[i];
-    // Format a text representation of the frame based on the information
-    // available.
-    SNPrintF(MutableCStrVector(frames[i].text, kStackWalkMaxTextLen),
-             "%s",
-             symbols[i]);
-    // Make sure line termination is in place.
-    frames[i].text[kStackWalkMaxTextLen - 1] = '\0';
-  }
-
-  free(symbols);
-
-  return frames_count;
-#else  // defined(__GLIBC__) && !defined(__UCLIBC__)
+  return POSIXBacktraceHelper<backtrace, backtrace_symbols>::StackWalk(frames);
+#else
   return 0;
-#endif  // defined(__GLIBC__) && !defined(__UCLIBC__)
+#endif
 }
 
 
@@ -862,56 +849,6 @@ void Thread::SetThreadLocal(LocalStorageKey key, void* value) {
 }
 
 
-void Thread::YieldCPU() {
-  sched_yield();
-}
-
-
-class LinuxMutex : public Mutex {
- public:
-  LinuxMutex() {
-    pthread_mutexattr_t attrs;
-    int result = pthread_mutexattr_init(&attrs);
-    ASSERT(result == 0);
-    result = pthread_mutexattr_settype(&attrs, PTHREAD_MUTEX_RECURSIVE);
-    ASSERT(result == 0);
-    result = pthread_mutex_init(&mutex_, &attrs);
-    ASSERT(result == 0);
-    USE(result);
-  }
-
-  virtual ~LinuxMutex() { pthread_mutex_destroy(&mutex_); }
-
-  virtual int Lock() {
-    int result = pthread_mutex_lock(&mutex_);
-    return result;
-  }
-
-  virtual int Unlock() {
-    int result = pthread_mutex_unlock(&mutex_);
-    return result;
-  }
-
-  virtual bool TryLock() {
-    int result = pthread_mutex_trylock(&mutex_);
-    // Return false if the lock is busy and locking failed.
-    if (result == EBUSY) {
-      return false;
-    }
-    ASSERT(result == 0);  // Verify no other errors.
-    return true;
-  }
-
- private:
-  pthread_mutex_t mutex_;   // Pthread mutex for POSIX platforms.
-};
-
-
-Mutex* OS::CreateMutex() {
-  return new LinuxMutex();
-}
-
-
 class LinuxSemaphore : public Semaphore {
  public:
   explicit LinuxSemaphore(int count) {  sem_init(&sem_, 0, count); }