Partially implement DBC profiler.

Partially implement DBC profiler.

 - Fix setting exit frame info to indicate when we are executing Dart code.
 - Copy local pc to memory on call and return to make it accessible to the profiler. Since the profiler cannot access the local pc, the profiler is not accurate at the instruction level.
 - Teach the profiler's stack walker that the stack grows up for Dart frames on DBC.

R=johnmccutchan@google.com

Committed: https://github.com/dart-lang/sdk/commit/59c52a5b6428e677d5f7515185bb0dafa9796b31

[rmacnak, 2016-08-19 00:22:32]

rmacnak@google.com changed reviewers:
+ johnmccutchan@google.com, zra@google.com

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

LGTM w/c

https://chromiumcodereview.appspot.com/2250823002/diff/40001/runtime/vm/profi...
File runtime/vm/profiler.cc (right):

https://chromiumcodereview.appspot.com/2250823002/diff/40001/runtime/vm/profi...
runtime/vm/profiler.cc:534: // FP didn't move to a higher address.
fix comment

https://chromiumcodereview.appspot.com/2250823002/diff/40001/runtime/vm/profi...
runtime/vm/profiler.cc:864: if (!in_dart_code && sp > *stack_lower) {
can this "!in_dart_code" be made DBC specific somehow?

https://chromiumcodereview.appspot.com/2250823002/diff/40001/runtime/vm/profi...
runtime/vm/profiler.cc:1161: #if defined(TARGET_ARCH_DBC)
why not fold this into:

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

https://chromiumcodereview.appspot.com/2250823002/diff/40001/runtime/vm/simul...
File runtime/vm/simulator_dbc.cc (right):

https://chromiumcodereview.appspot.com/2250823002/diff/40001/runtime/vm/simul...
runtime/vm/simulator_dbc.cc:545: pc_ = reinterpret_cast<uword>(*pc);  // For the
profiler.
weird indentation

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

https://chromiumcodereview.appspot.com/2250823002/diff/40001/runtime/vm/profi...
File runtime/vm/profiler.cc (right):

https://chromiumcodereview.appspot.com/2250823002/diff/40001/runtime/vm/profi...
runtime/vm/profiler.cc:864: if (!in_dart_code && sp > *stack_lower) {
please add parens (sp > *stack_lower)

[rmacnak, 2016-08-19 23:28:17]

https://codereview.chromium.org/2250823002/diff/40001/runtime/vm/profiler.cc
File runtime/vm/profiler.cc (right):

https://codereview.chromium.org/2250823002/diff/40001/runtime/vm/profiler.cc#...
runtime/vm/profiler.cc:534: // FP didn't move to a higher address.
On 2016/08/19 13:49:31, Cutch wrote:
> fix comment

Done.

https://codereview.chromium.org/2250823002/diff/40001/runtime/vm/profiler.cc#...
runtime/vm/profiler.cc:864: if (!in_dart_code && sp > *stack_lower) {
On 2016/08/19 13:49:31, Cutch wrote:
> can this "!in_dart_code" be made DBC specific somehow?

Done.

https://codereview.chromium.org/2250823002/diff/40001/runtime/vm/profiler.cc#...
runtime/vm/profiler.cc:1161: #if defined(TARGET_ARCH_DBC)
On 2016/08/19 13:49:31, Cutch wrote:
> why not fold this into:
> 
> #if defined(TARGET_ARCH_DBC) || defined(USING_SIMULATOR)
> simulator = isolate->simulator();
> sp = ..
> fp = ..
> pc = ..
> #else
> ...

DBC doesn't define Simulator::get_register.

https://codereview.chromium.org/2250823002/diff/40001/runtime/vm/simulator_db...
File runtime/vm/simulator_dbc.cc (right):

https://codereview.chromium.org/2250823002/diff/40001/runtime/vm/simulator_db...
runtime/vm/simulator_dbc.cc:545: pc_ = reinterpret_cast<uword>(*pc);  // For the
profiler.
On 2016/08/19 13:49:31, Cutch wrote:
> weird indentation

It is indented the same as the other lines, the asterisks just visually seem to
take up less space.

[rmacnak, 2016-08-19 23:48:38]

Description was changed from

==========
Partially implement DBC profiler.

 - Fix setting exit frame info to indicate when we are executing Dart code.
 - Copy local pc to memory on call and return to make it accessible to the
profiler. Since the profiler cannot access the local pc, the profiler is not
accurate at the instruction level.
 - Teach the profiler's stack walker that the stack grows up for Dart frames on
DBC.
==========

to

==========
Partially implement DBC profiler.

 - Fix setting exit frame info to indicate when we are executing Dart code.
 - Copy local pc to memory on call and return to make it accessible to the
profiler. Since the profiler cannot access the local pc, the profiler is not
accurate at the instruction level.
 - Teach the profiler's stack walker that the stack grows up for Dart frames on
DBC.

R=johnmccutchan@google.com

Committed:
https://github.com/dart-lang/sdk/commit/59c52a5b6428e677d5f7515185bb0dafa9796b31
==========

[rmacnak, 2016-08-19 23:48:39]

Committed patchset #5 (id:80001) manually as
59c52a5b6428e677d5f7515185bb0dafa9796b31 (presubmit successful).