Fix processing profiler samples in the presence of Thumb code.

Fix processing profiler samples in the presence of Thumb code.

R=zra@google.com

Committed: https://github.com/dart-lang/sdk/commit/e666436d05f64c12105b9bf0d19961f663824dbb

[rmacnak, 2015-10-30 18:14:27]

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

[zra, 2015-10-30 18:28:31]

https://codereview.chromium.org/1410543011/diff/20001/runtime/vm/profiler_ser...
File runtime/vm/profiler_service.cc (right):

https://codereview.chromium.org/1410543011/diff/20001/runtime/vm/profiler_ser...
runtime/vm/profiler_service.cc:1909: #if defined(HOST_ARCH_ARM)
We should probably check that __thumb__ or __thumb2__ is defined so that
something will still go wrong when the VM is not compiled to thumb code.

https://codereview.chromium.org/1410543011/diff/20001/runtime/vm/profiler_ser...
runtime/vm/profiler_service.cc:1910: if ((native_start % 2) == 1) {
unconditionally:
const uintptr_t one = 1;
native_start &= ~one;

[rmacnak, 2015-10-30 18:36:50]

https://codereview.chromium.org/1410543011/diff/20001/runtime/vm/profiler_ser...
File runtime/vm/profiler_service.cc (right):

https://codereview.chromium.org/1410543011/diff/20001/runtime/vm/profiler_ser...
runtime/vm/profiler_service.cc:1909: #if defined(HOST_ARCH_ARM)
On 2015/10/30 18:28:31, zra wrote:
> We should probably check that __thumb__ or __thumb2__ is defined so that
> something will still go wrong when the VM is not compiled to thumb code.

Other compilation units or dynamic libraries in our process might still have
thumb code.

https://codereview.chromium.org/1410543011/diff/20001/runtime/vm/profiler_ser...
runtime/vm/profiler_service.cc:1910: if ((native_start % 2) == 1) {
On 2015/10/30 18:28:30, zra wrote:
> unconditionally:
> const uintptr_t one = 1;
> native_start &= ~one;

Done.

[Florian Schneider, 2015-10-30 19:12:02]

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

[Florian Schneider, 2015-10-30 19:12:02]

dbc:

https://codereview.chromium.org/1410543011/diff/20001/runtime/vm/profiler_ser...
File runtime/vm/profiler_service.cc (right):

https://codereview.chromium.org/1410543011/diff/20001/runtime/vm/profiler_ser...
runtime/vm/profiler_service.cc:1910: if ((native_start % 2) == 1) {
On 2015/10/30 18:28:30, zra wrote:
> unconditionally:
> const uintptr_t one = 1;
> native_start &= ~one;

I'd 1U for unsigned literal one. Here however, signed-ness does not matter ( &
and ~). So my guess is that '&= ~1' should just work as expected.

[zra, 2015-10-30 19:18:09]

lgtm

[rmacnak, 2015-10-30 19:48:51]

https://codereview.chromium.org/1410543011/diff/20001/runtime/vm/profiler_ser...
File runtime/vm/profiler_service.cc (right):

https://codereview.chromium.org/1410543011/diff/20001/runtime/vm/profiler_ser...
runtime/vm/profiler_service.cc:1910: if ((native_start % 2) == 1) {
On 2015/10/30 19:12:02, Florian Schneider wrote:
> On 2015/10/30 18:28:30, zra wrote:
> > unconditionally:
> > const uintptr_t one = 1;
> > native_start &= ~one;
> 
> I'd 1U for unsigned literal one. Here however, signed-ness does not matter ( &
> and ~). So my guess is that '&= ~1' should just work as expected.

ack

[rmacnak, 2015-10-30 19:49:36]

Committed patchset #4 (id:60001) manually as
e666436d05f64c12105b9bf0d19961f663824dbb (presubmit successful).