Enable native stack walking for allocation profiling

Enable native stack walking for allocation profiling

- Use native stack walker for allocation profiling when --profile-vm is passed
- Helpers for retrieving SP, FP, and PC registers
- Refactor sampler code to share more code between allocation sampling / interrupt sampling
- Export all symbols into the dynamic symbol table for run_vm_tests (already doing this for Dart executable)

R=regis@google.com

Committed: https://github.com/dart-lang/sdk/commit/a1798f7e456dc921e14329faa7ecccca939ef644

[Cutch, 2015-08-05 17:09:50]

johnmccutchan@google.com changed reviewers:
+ iposva@google.com

[regis, 2015-08-05 19:37:13]

regis@google.com changed reviewers:
+ regis@google.com

[regis, 2015-08-05 19:37:14]

https://codereview.chromium.org/1274663004/diff/1/runtime/vm/globals.h
File runtime/vm/globals.h (right):

https://codereview.chromium.org/1274663004/diff/1/runtime/vm/globals.h#newcod...
runtime/vm/globals.h:117: #define COPY_FP_REGISTER(fp) UNIMPLEMENTED();
Not tested, but you can try:
#define COPY_SP_REGISTER(sp) asm volatile ("mov %0, sp" : "=r" (sp) );
#define COPY_SP_REGISTER(fp) asm volatile ("mov %0, fp" : "=r" (fp) );
or
#define COPY_SP_REGISTER(sp) asm volatile ("mov %0, r13" : "=r" (sp) );
#define COPY_SP_REGISTER(fp) asm volatile ("mov %0, r11" : "=r" (fp) );

https://codereview.chromium.org/1274663004/diff/1/runtime/vm/globals.h#newcod...
runtime/vm/globals.h:120: #define COPY_FP_REGISTER(fp) UNIMPLEMENTED();
Not tested, but you can try:
#define COPY_SP_REGISTER(sp) asm volatile ("mov %0, sp" : "=r" (sp) );
#define COPY_SP_REGISTER(fp) asm volatile ("mov %0, fp" : "=r" (fp) );
or
#define COPY_SP_REGISTER(fp) asm volatile ("mov %0, x29" : "=r" (fp) );

https://codereview.chromium.org/1274663004/diff/1/runtime/vm/globals.h#newcod...
runtime/vm/globals.h:123: #define COPY_FP_REGISTER(fp) UNIMPLEMENTED();
Not tested, but you can try:
#define COPY_SP_REGISTER(sp) asm volatile ("move %0, sp" : "=r" (sp) );
#define COPY_SP_REGISTER(fp) asm volatile ("move %0, fp" : "=r" (fp) );
or
#define COPY_SP_REGISTER(sp) asm volatile ("move %0, r29" : "=r" (sp) );
#define COPY_SP_REGISTER(fp) asm volatile ("move %0, r30" : "=r" (fp) );

[Florian Schneider, 2015-08-06 10:15:28]

fschneider@google.com changed reviewers:
+ fschneider@google.com

[Florian Schneider, 2015-08-06 10:15:28]

https://codereview.chromium.org/1274663004/diff/40001/runtime/vm/profiler.cc
File runtime/vm/profiler.cc (right):

https://codereview.chromium.org/1274663004/diff/40001/runtime/vm/profiler.cc#...
runtime/vm/profiler.cc:987: COPY_SP_REGISTER(sp);
We also have a GetStackPointer stub. Does Isolate::GetCurrentStackPointer() not
work here?

[Cutch, 2015-08-06 14:22:55]

PTAL

[regis, 2015-08-06 16:55:17]

LGTM

https://codereview.chromium.org/1274663004/diff/60001/runtime/vm/profiler.cc
File runtime/vm/profiler.cc (right):

https://codereview.chromium.org/1274663004/diff/60001/runtime/vm/profiler.cc#...
runtime/vm/profiler.cc:987: COPY_FP_REGISTER(fp);
I suppose you tell gcc to always generate frame pointers? Otherwise this would
be meaningless.

[Cutch, 2015-08-06 20:26:19]

On 2015/08/06 16:55:17, regis wrote:
> LGTM
> 
> https://codereview.chromium.org/1274663004/diff/60001/runtime/vm/profiler.cc
> File runtime/vm/profiler.cc (right):
> 
>
https://codereview.chromium.org/1274663004/diff/60001/runtime/vm/profiler.cc#...
> runtime/vm/profiler.cc:987: COPY_FP_REGISTER(fp);
> I suppose you tell gcc to always generate frame pointers? Otherwise this would
> be meaningless.

This code only runs if --profile-vm is passed as a flag and that flag does
require frame pointers to work properly.

[Cutch, 2015-08-06 20:32:01]

Committed patchset #6 (id:100001) manually as
a1798f7e456dc921e14329faa7ecccca939ef644 (presubmit successful).