Fix the debugger for strict-mode functions.

Fix the debugger for strict-mode functions.

undefined is passed unchanged as the receiver for strict-mode
functions through call and apply. Also, if a strict-mode function is
called without an explicit receiver, undefined is passed as the
receiver (not the global object as for other functions).

R=vegorov@chromium.org
BUG=89236
TEST=mjsunit/debug-scopes.js

Committed: http://code.google.com/p/v8/source/detail?r=8675

[Vyacheslav Egorov (Chromium), 2011-07-15 12:43:13]

http://codereview.chromium.org/7388011/diff/1/src/runtime.cc
File src/runtime.cc (right):

http://codereview.chromium.org/7388011/diff/1/src/runtime.cc#newcode10302
src/runtime.cc:10302: if (!receiver->IsJSObject() && !receiver->IsUndefined()) {
I think we should check for strict || builtin function instead. Receivers of all
other functions should be wrapped.

I think we have general problem with non-jsobject receivers for strict
functions.

function f() { "use strict"; debugger; }
f.apply("x");

will display this as String object in the debugger while it is actually a
primitive. (But it will not crash).

[Mads Ager (chromium), 2011-07-15 16:32:09]

Randomly adding Vitaly as a new reviewer since Slava is now on vacation.

http://codereview.chromium.org/7388011/diff/1/src/runtime.cc
File src/runtime.cc (right):

http://codereview.chromium.org/7388011/diff/1/src/runtime.cc#newcode10302
src/runtime.cc:10302: if (!receiver->IsJSObject() && !receiver->IsUndefined()) {
On 2011/07/15 12:43:13, Vyacheslav Egorov wrote:
> I think we should check for strict || builtin function instead. Receivers of
all
> other functions should be wrapped.
> 
> I think we have general problem with non-jsobject receivers for strict
> functions.
> 
> function f() { "use strict"; debugger; }
> f.apply("x");
> 
> will display this as String object in the debugger while it is actually a
> primitive. (But it will not crash).

D'oh! You are absolutely right. Thank you. :-)

That change requires a couple of extra changes as well because the receiver can
now be primitive values as well as undefined and objects.

[Mads Ager (chromium), 2011-07-15 17:53:10]

Ready for another look.

Added new test file that actually tests that the receiver is as expected in the
debugger.

The setup for debugger tests is a little involved because the exceptions thrown
in the debug even listener are not propagated and should not be. I am following
the style in the other tests to deal with that.

[Vitaly Repeshko, 2011-07-18 13:04:49]

LGTM

http://codereview.chromium.org/7388011/diff/2002/src/mirror-debugger.js
File src/mirror-debugger.js (right):

http://codereview.chromium.org/7388011/diff/2002/src/mirror-debugger.js#newco...
src/mirror-debugger.js:1609: for (var r = receiver; !r.isNull() &&
property.isUndefined(); r = r.protoObject()) {
nit: While we're here let's fix the long line.

http://codereview.chromium.org/7388011/diff/2002/test/mjsunit/debug-receiver.js
File test/mjsunit/debug-receiver.js (right):

http://codereview.chromium.org/7388011/diff/2002/test/mjsunit/debug-receiver....
test/mjsunit/debug-receiver.js:93: BeginTest("strict: 1"); TestStrict(1);
EndTest();
Add heap number?

http://codereview.chromium.org/7388011/diff/2002/test/mjsunit/debug-receiver....
test/mjsunit/debug-receiver.js:116: BeginTest("non-strict: 1");
TestNonStrict(1); EndTest();
Ditto.

[Mads Ager (chromium), 2011-07-18 14:27:07]

Thanks Vitaly!

http://codereview.chromium.org/7388011/diff/2002/src/mirror-debugger.js
File src/mirror-debugger.js (right):

http://codereview.chromium.org/7388011/diff/2002/src/mirror-debugger.js#newco...
src/mirror-debugger.js:1609: for (var r = receiver; !r.isNull() &&
property.isUndefined(); r = r.protoObject()) {
On 2011/07/18 13:04:50, Vitaly Repeshko wrote:
> nit: While we're here let's fix the long line.

Done.

http://codereview.chromium.org/7388011/diff/2002/test/mjsunit/debug-receiver.js
File test/mjsunit/debug-receiver.js (right):

http://codereview.chromium.org/7388011/diff/2002/test/mjsunit/debug-receiver....
test/mjsunit/debug-receiver.js:93: BeginTest("strict: 1"); TestStrict(1);
EndTest();
On 2011/07/18 13:04:50, Vitaly Repeshko wrote:
> Add heap number?

Done.

http://codereview.chromium.org/7388011/diff/2002/test/mjsunit/debug-receiver....
test/mjsunit/debug-receiver.js:116: BeginTest("non-strict: 1");
TestNonStrict(1); EndTest();
On 2011/07/18 13:04:50, Vitaly Repeshko wrote:
> Ditto.

Done.