Make Isolate::GetStackSample API support simulator

src/profiler/sampler.h

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_PROFILER_SAMPLER_H_
 #define V8_PROFILER_SAMPLER_H_
 
 #include "include/v8.h"
 
 #include "src/base/atomicops.h"
 #include "src/base/platform/time.h"
 #include "src/frames.h"
 #include "src/globals.h"
+#include "src/simulator.h"
 
 namespace v8 {
 namespace internal {
 
 class Isolate;
 
 // ----------------------------------------------------------------------------
 // Sampler
 //
 // A sampler periodically samples the state of the VM and optionally
@@ skipping 110 matching lines @@
   base::Atomic32 registered_;
   PlatformData* data_;  // Platform specific data.
   // Counts stack samples taken in various VM states.
   bool is_counting_samples_;
   unsigned js_sample_count_;
   unsigned external_sample_count_;
   DISALLOW_IMPLICIT_CONSTRUCTORS(Sampler);
 };
 
 
+#if defined(USE_SIMULATOR)
+class SimulatorHelper : AllStatic {
+ public:
+  inline static bool FillRegisters(Isolate* isolate, v8::RegisterState* state) {

[alph, 2016/04/29 18:55:06]

Please don't put such a big function definition in .h
You can leave it in sampler.cc

[lpy, 2016/04/29 19:51:58]

Done.

+    Simulator *simulator = isolate->thread_local_top()->simulator_;
+    // Check if there is active simulator.
+    if (simulator == NULL) return false;
+#if V8_TARGET_ARCH_ARM
+    if (!simulator->has_bad_pc()) {
+      state->pc = reinterpret_cast<Address>(simulator->get_pc());
+    }
+    state->sp = reinterpret_cast<Address>(simulator->get_register(
+        Simulator::sp));
+    state->fp = reinterpret_cast<Address>(simulator->get_register(
+        Simulator::r11));
+#elif V8_TARGET_ARCH_ARM64
+    if (simulator->sp() == 0 || simulator->fp() == 0) {
+      // It's possible that the simulator is interrupted while it is updating
+      // the sp or fp register. ARM64 simulator does this in two steps:
+      // first setting it to zero and then setting it to a new value.
+      // Bailout if sp/fp doesn't contain the new value.
+      //
+      // FIXME: The above doesn't really solve the issue.
+      // If a 64-bit target is executed on a 32-bit host even the final
+      // write is non-atomic, so it might obtain a half of the result.
+      // Moreover as long as the register set code uses memcpy (as of now),
+      // it is not guaranteed to be atomic even when both host and target
+      // are of same bitness.
+      return true;
+    }
+    state->pc = reinterpret_cast<Address>(simulator->pc());
+    state->sp = reinterpret_cast<Address>(simulator->sp());
+    state->fp = reinterpret_cast<Address>(simulator->fp());
+#elif V8_TARGET_ARCH_MIPS || V8_TARGET_ARCH_MIPS64
+    if (!simulator->has_bad_pc()) {
+      state->pc = reinterpret_cast<Address>(simulator->get_pc());
+    }
+    state->sp = reinterpret_cast<Address>(simulator->get_register(
+        Simulator::sp));
+    state->fp = reinterpret_cast<Address>(simulator->get_register(
+        Simulator::fp));
+#elif V8_TARGET_ARCH_PPC
+    if (!simulator->has_bad_pc()) {
+      state->pc = reinterpret_cast<Address>(simulator->get_pc());
+    }
+    state->sp =
+        reinterpret_cast<Address>(simulator->get_register(Simulator::sp));
+    state->fp =
+        reinterpret_cast<Address>(simulator->get_register(Simulator::fp));
+#elif V8_TARGET_ARCH_S390
+    if (!simulator->has_bad_pc()) {
+      state->pc = reinterpret_cast<Address>(simulator->get_pc());
+    }
+    state->sp =
+        reinterpret_cast<Address>(simulator->get_register(Simulator::sp));
+    state->fp =
+        reinterpret_cast<Address>(simulator->get_register(Simulator::fp));
+#endif
+    return true;
+  }
+};
+#endif  // USE_SIMULATOR
+
+
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_PROFILER_SAMPLER_H_