Partially implement DBC profiler.

runtime/vm/profiler.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 "platform/address_sanitizer.h"
 #include "platform/memory_sanitizer.h"
 #include "platform/utils.h"
 
 #include "vm/allocation.h"
 #include "vm/atomic.h"
@@ skipping 511 matching lines @@
       return NextExit();
     }
     // In regular Dart frame.
     uword* new_pc = CallerPC();
     // Check if we've moved into the invocation stub.
     if (StubCode::InInvocationStub(reinterpret_cast<uword>(new_pc))) {
       // New PC is inside invocation stub, skip.
       return NextExit();
     }
     uword* new_fp = CallerFP();
-    if (new_fp <= fp_) {
+    if (!IsCalleeFrameOf(reinterpret_cast<uword>(new_fp),
+                         reinterpret_cast<uword>(fp_))) {
       // FP didn't move to a higher address.

[Cutch, 2016/08/19 13:49:31]

fix comment

[rmacnak, 2016/08/19 23:28:16]

Done.

       return false;
     }
     // Success, update fp and pc.
     fp_ = new_fp;
     pc_ = new_pc;
     return true;
   }
 
   bool NextExit() {
     if (!ValidFramePointer()) {
@@ skipping 286 matching lines @@
 static bool GetAndValidateIsolateStackBounds(Thread* thread,
                                              uintptr_t fp,
                                              uintptr_t sp,
                                              uword* stack_lower,
                                              uword* stack_upper) {
   ASSERT(thread != NULL);
   OSThread* os_thread = thread->os_thread();
   ASSERT(os_thread != NULL);
   ASSERT(stack_lower != NULL);
   ASSERT(stack_upper != NULL);
+  const bool in_dart_code = thread->IsExecutingDartCode();
 #if defined(USING_SIMULATOR)
-  const bool in_dart_code = thread->IsExecutingDartCode();
   if (in_dart_code) {
     Isolate* isolate = thread->isolate();
     ASSERT(isolate != NULL);
     Simulator* simulator = isolate->simulator();
     *stack_lower = simulator->StackBase();
     *stack_upper = simulator->StackTop();
   } else if (!os_thread->GetProfilerStackBounds(stack_lower, stack_upper)) {
     // Could not get stack boundary.
     return false;
   }
   if ((*stack_lower == 0) || (*stack_upper == 0)) {
     return false;
   }
 #else
   if (!os_thread->GetProfilerStackBounds(stack_lower, stack_upper) ||
       (*stack_lower == 0) || (*stack_upper == 0)) {
     // Could not get stack boundary.
     return false;
   }
 #endif
-  if (sp > *stack_lower) {
+
+  if (!in_dart_code && sp > *stack_lower) {

[Cutch, 2016/08/19 13:49:31]

can this "!in_dart_code" be made DBC specific somehow?

[zra, 2016/08/19 15:40:08]

please add parens (sp > *stack_lower)

[rmacnak, 2016/08/19 23:28:16]

Done.

     // The stack pointer gives us a tighter lower bound.
     *stack_lower = sp;
   }
 
   if (*stack_lower >= *stack_upper) {
     // Stack boundary is invalid.
     return false;
   }
 
   if ((sp < *stack_lower) || (sp >= *stack_upper)) {
@@ skipping 245 matching lines @@
     counters->Increment(sample->vm_tag());
   }
 
   // Write the single pc value.
   sample->SetAt(0, pc);
 }
 
 
 void Profiler::SampleThread(Thread* thread,
                             const InterruptedThreadState& state) {
-#if defined(TARGET_ARCH_DBC)
-  // TODO(vegorov) implement simulator stack sampling.
-  return;
-#endif
-
   ASSERT(thread != NULL);
   OSThread* os_thread = thread->os_thread();
   ASSERT(os_thread != NULL);
   Isolate* isolate = thread->isolate();
 
   // Thread is not doing VM work.
   if (thread->task_kind() == Thread::kUnknownTask) {
     counters_.bail_out_unknown_task++;
     return;
   }
 
   if (StubCode::HasBeenInitialized() &&
       StubCode::InJumpToExceptionHandlerStub(state.pc)) {
     // The JumpToExceptionHandler stub manually adjusts the stack pointer,
     // frame pointer, and some isolate state before jumping to a catch entry.
     // It is not safe to walk the stack when executing this stub.
     counters_.bail_out_jump_to_exception_handler++;
     return;
   }
 
   const bool in_dart_code = thread->IsExecutingDartCode();
 
   uintptr_t sp = 0;
   uintptr_t fp = state.fp;
   uintptr_t pc = state.pc;
-#if defined(USING_SIMULATOR) && !defined(TARGET_ARCH_DBC)
+#if defined(USING_SIMULATOR)
   Simulator* simulator = NULL;
 #endif
 
   if (in_dart_code) {
     // If we're in Dart code, use the Dart stack pointer.
 #if defined(TARGET_ARCH_DBC)

[Cutch, 2016/08/19 13:49:31]

why not fold this into:

#if defined(TARGET_ARCH_DBC) || defined(USING_SIMULATOR)
simulator = isolate->simulator();
sp = ..
fp = ..
pc = ..
#else
...

[rmacnak, 2016/08/19 23:28:16]

DBC doesn't define Simulator::get_register.

-    UNIMPLEMENTED();
+    simulator = isolate->simulator();
+    sp = simulator->get_sp();
+    fp = simulator->get_fp();
+    pc = simulator->get_pc();
 #elif defined(USING_SIMULATOR)
     simulator = isolate->simulator();
     sp = simulator->get_register(SPREG);
     fp = simulator->get_register(FPREG);
     pc = simulator->get_pc();
 #else
     sp = state.dsp;
 #endif
   } else {
     // If we're in runtime code, use the C stack pointer.
@@ skipping 413 matching lines @@
 
 
 ProcessedSampleBuffer::ProcessedSampleBuffer()
     : code_lookup_table_(new CodeLookupTable(Thread::Current())) {
   ASSERT(code_lookup_table_ != NULL);
 }
 
 #endif  // !PRODUCT
 
 }  // namespace dart