Add Function based profile tree

runtime/vm/signal_handler_linux.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"
 #include "vm/simulator.h"
 #include "vm/signal_handler.h"
 #if defined(TARGET_OS_LINUX)
 
 namespace dart {
@@ skipping 79 matching lines @@
 
 uintptr_t SignalHandler::GetDartStackPointer(const mcontext_t& mcontext) {
 #if defined(TARGET_ARCH_ARM64) && !defined(USING_SIMULATOR)
   return static_cast<uintptr_t>(mcontext.regs[18]);
 #else
   return GetCStackPointer(mcontext);
 #endif
 }
 
 
+uintptr_t SignalHandler::GetLinkRegister(const mcontext_t& mcontext) {
+  uintptr_t lr = 0;
+
+#if defined(TARGET_ARCH_IA32)
+  lr = 0;
+#elif defined(TARGET_ARCH_X64)
+  lr = 0;
+#elif defined(TARGET_ARCH_MIPS) && defined(USING_SIMULATOR)
+  lr = 0;
+#elif defined(TARGET_ARCH_ARM) && defined(USING_SIMULATOR)
+  lr = 0;
+#elif defined(TARGET_ARCH_ARM64) && defined(USING_SIMULATOR)
+  lr = 0;
+#elif defined(TARGET_ARCH_ARM)
+  lr = static_cast<uintptr_t>(mcontext.arm_lr);
+#elif defined(TARGET_ARCH_ARM64)
+  lr = static_cast<uintptr_t>(mcontext.lr);
+#elif defined(TARGET_ARCH_MIPS)
+  lr = static_cast<uintptr_t>(mcontext.gregs[31]);
+#else
+  UNIMPLEMENTED();
+#endif  // TARGET_ARCH_...
+  return lr;
+}
+
+
 void SignalHandler::Install(SignalAction action) {
   struct sigaction act;
   act.sa_handler = NULL;
   act.sa_sigaction = action;
   sigemptyset(&act.sa_mask);
   act.sa_flags = SA_RESTART | SA_SIGINFO;
   // TODO(johnmccutchan): Do we care about restoring the signal handler?
   struct sigaction old_act;
   int r = sigaction(SIGPROF, &act, &old_act);
   ASSERT(r == 0);
 }
 
 
 }  // namespace dart
 
 #endif  // defined(TARGET_OS_LINUX)