Expose DumpBacktrace for debugging purposes.

Expose DumpBacktrace for debugging purposes.

After this change, you can just call DumpBacktrace in any function. Previously
the only function printing stack traces was V8_Fatal, but that also terminated
the program, so not very useful for debugging.

Note that DumpBacktrace is roughly equivalent to base::debug::StackTrace
functionality in Chromium, except less fancy, but it's enough for us.

R=mstarzinger@chromium.org
BUG=

Committed: https://code.google.com/p/v8/source/detail?r=19993

[marja, 2014-03-14 14:02:50]

ptal

[Michael Starzinger, 2014-03-14 14:29:19]

https://codereview.chromium.org/200343003/diff/1/src/checks.cc
File src/checks.cc (right):

https://codereview.chromium.org/200343003/diff/1/src/checks.cc#newcode96
src/checks.cc:96: }  // namespace internal
nit: Can we get the usual one-line incarnation that closes the full namespace in
one line? Or is that actually against the style guide?

https://codereview.chromium.org/200343003/diff/1/src/checks.h
File src/checks.h (right):

https://codereview.chromium.org/200343003/diff/1/src/checks.h#newcode310
src/checks.h:310: void DumpBacktrace();
nit: Can we get a one-liner comment that this exposed for debugging purposes?
Otherwise someone might "clean it up" and remove it again.

[Michael Starzinger, 2014-03-14 14:29:30]

LGTM with nits.

[marja, 2014-03-17 10:50:07]

thx for review!

https://codereview.chromium.org/200343003/diff/1/src/checks.cc
File src/checks.cc (right):

https://codereview.chromium.org/200343003/diff/1/src/checks.cc#newcode96
src/checks.cc:96: }  // namespace internal
On 2014/03/14 14:29:19, Michael Starzinger wrote:
> nit: Can we get the usual one-line incarnation that closes the full namespace
in
> one line? Or is that actually against the style guide?

Done.

https://codereview.chromium.org/200343003/diff/1/src/checks.h
File src/checks.h (right):

https://codereview.chromium.org/200343003/diff/1/src/checks.h#newcode310
src/checks.h:310: void DumpBacktrace();
On 2014/03/14 14:29:19, Michael Starzinger wrote:
> nit: Can we get a one-liner comment that this exposed for debugging purposes?
> Otherwise someone might "clean it up" and remove it again.

Done.

[marja, 2014-03-17 11:09:03]

https://codereview.chromium.org/200343003/diff/1/src/checks.cc
File src/checks.cc (right):

https://codereview.chromium.org/200343003/diff/1/src/checks.cc#newcode96
src/checks.cc:96: }  // namespace internal
On 2014/03/17 10:50:07, marja wrote:
> On 2014/03/14 14:29:19, Michael Starzinger wrote:
> > nit: Can we get the usual one-line incarnation that closes the full
namespace
> in
> > one line? Or is that actually against the style guide?
> 
> Done.


Btw, the header used the two-line style, so made it use one-line style too. That
is, V8 is not consistent about which one to use.

[marja, 2014-03-17 13:33:27]

Committed patchset #5 manually as r19993 (presubmit successful).