Fix step in positions (include various calls and exclude current pc point), add a test

Fix step in positions (include various calls and exclude current pc point), add a test

R=yangguo@chromium.org

Committed: http://code.google.com/p/v8/source/detail?r=16100

[Peter.Rybin, 2013-08-05 13:39:12]

Hi Yang

I'm trying to polish step into feature. I added a test with some code examples
where I expect V8 to report step into positions.

Feel free to offer another examples of call sites that uses different assembler
underneath, because I cannot thing of all possible cases.

Peter

[Yang, 2013-08-06 09:33:16]

On 2013/08/05 13:39:12, peter.rybin wrote:
> Hi Yang
> 
> I'm trying to polish step into feature. I added a test with some code examples
> where I expect V8 to report step into positions.
> 
> Feel free to offer another examples of call sites that uses different
assembler
> underneath, because I cannot thing of all possible cases.
> 
> Peter

LGTM with nits.

you might also want to add tests for:

- keyed calls. like
var a = [ function() { }]; a[0]();

- ES5 getters and setters,

- accessors, like the .length property of strings and arrays.

[Yang, 2013-08-06 09:33:26]

https://chromiumcodereview.appspot.com/22198002/diff/4001/test/mjsunit/debug-...
File test/mjsunit/debug-stepin-positions.js (right):

https://chromiumcodereview.appspot.com/22198002/diff/4001/test/mjsunit/debug-...
test/mjsunit/debug-stepin-positions.js:112: var res = [ DebuggerStatement(),
data./*#*/a(), data[/*#*/String("a")]/*#*/(), data["a"]/*#*/(), data.a,
data["a"] ];
80 char limit.

[Peter.Rybin, 2013-08-06 15:40:00]

> you might also want to add tests for:
> - keyed calls. like
> var a = [ function() { }]; a[0]();
I already have test against object method. I thought that is the same code.

> - ES5 getters and setters,
TBD

> - accessors, like the .length property of strings and arrays.
How can I put it as a step into position? You cannot normally step into .length
expression.
On the other hand, I may try to check for false positive in this case?

[Peter.Rybin, 2013-08-06 15:40:58]

On 2013/08/06 09:33:26, Yang wrote:
>
https://chromiumcodereview.appspot.com/22198002/diff/4001/test/mjsunit/debug-...
> File test/mjsunit/debug-stepin-positions.js (right):
> 
>
https://chromiumcodereview.appspot.com/22198002/diff/4001/test/mjsunit/debug-...
> test/mjsunit/debug-stepin-positions.js:112: var res = [ DebuggerStatement(),
> data./*#*/a(), data[/*#*/String("a")]/*#*/(), data["a"]/*#*/(), data.a,
> data["a"] ];
> 80 char limit.

This is hard to fix, since I rely on the statement being a single line -- I
fetch the code snippet from the call frame.

[Peter.Rybin, 2013-08-07 12:27:29]

Committed patchset #3 manually as r16100 (presubmit successful).