Handled return-value of SetElement in some cases, or avoided it in other.

Handled return-value of SetElement in some cases, or avoided it in other.

SetElement can cause an exception to be thrown. If its return value
isn't checked, this exception might not be handled at the correct time.
In some cases, it's a matter of returning Exception::Failure() from
a runtime function.
In other cases, code using SetElement on a JSArray has been changed
to setting directly on a FixedArray and only creating the JSArray
at the end.

Committed: http://code.google.com/p/v8/source/detail?r=7039

[antonm, 2011-03-02 20:28:47]

Drive-by comments

http://codereview.chromium.org/6588130/diff/1/src/runtime.cc
File src/runtime.cc (right):

http://codereview.chromium.org/6588130/diff/1/src/runtime.cc#newcode1473
src/runtime.cc:1473: if (result.is_null()) return Failure::Exception();
you may use RETURN_IF_EMPTY_HANDLE

http://codereview.chromium.org/6588130/diff/1/src/runtime.cc#newcode8663
src/runtime.cc:8663: if (SetElement(jsobject, index1, tmp2).is_null()) {
Ditto

[Søren Thygesen Gjesse, 2011-03-03 07:47:04]

LGTM

In objects.h SetElement if declared with MUST_USE_RESULT, which for GCC 4.x is
"__attribute__ ((warn_unused_result))". Should we do the same for SetElement in
handles.h?

[Søren Thygesen Gjesse, 2011-03-03 10:14:22]

LGTM for the GetElements as well.

[Lasse Reichstein, 2011-03-03 10:16:01]

Thanks.
We should make SetElement MUST_USE_RESULT as soon as we have handled it
everywhere.