Allow new CPU profiling subsystem to coexist nicely with the old one.

src/platform-linux.cc

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 709 matching lines @@
   return false;
 }
 
 
 static void ProfilerSignalHandler(int signal, siginfo_t* info, void* context) {
 #ifndef V8_HOST_ARCH_MIPS
   USE(info);
   if (signal != SIGPROF) return;
   if (active_sampler_ == NULL) return;
 
+  TickSample sample_obj;
+  TickSample* sample = NULL;
 #ifdef ENABLE_CPP_PROFILES_PROCESSOR
-  TickSample* sample = CpuProfiler::TickSampleEvent();
-  if (sample == NULL) return;
-  sample->pc = NULL;  // Impossible value if sampling succeeds.
-  sample->frames_count = 0;
-#else
-  TickSample sample_obj;
-  TickSample* sample = &sample_obj;
+  sample = CpuProfiler::TickSampleEvent();
 #endif
+  if (sample == NULL) sample = &sample_obj;
 
   // We always sample the VM state.
   sample->state = VMState::current_state();
   // If profiling, we extract the current pc and sp.
   if (active_sampler_->IsProfiling()) {
     // Extracting the sample from the context is extremely machine dependent.
     ucontext_t* ucontext = reinterpret_cast<ucontext_t*>(context);
     mcontext_t& mcontext = ucontext->uc_mcontext;
 #if V8_HOST_ARCH_IA32
     sample->pc = reinterpret_cast<Address>(mcontext.gregs[REG_EIP]);
@@ skipping 15 matching lines @@
     sample->fp = reinterpret_cast<Address>(mcontext.arm_fp);
 #endif
 #elif V8_HOST_ARCH_MIPS
     // Implement this on MIPS.
     UNIMPLEMENTED();
 #endif
     if (IsVmThread()) {
       active_sampler_->SampleStack(sample);
     }
   }
-#ifndef ENABLE_CPP_PROFILES_PROCESSOR
+
   active_sampler_->Tick(sample);
 #endif
-#endif
 }
 
 
 class Sampler::PlatformData : public Malloced {
  public:
   PlatformData() {
     signal_handler_installed_ = false;
   }
 
   bool signal_handler_installed_;
@@ skipping 52 matching lines @@
 
   // This sampler is no longer the active sampler.
   active_sampler_ = NULL;
   active_ = false;
 }
 
 
 #endif  // ENABLE_LOGGING_AND_PROFILING
 
 } }  // namespace v8::internal