Add ScopeTypeCatch to ScopeIterator

Added new scope type ScopeIterator::ScopeTypeCatch for with generated from catch blocks.

Removed a false assertion in ScopeIterator that assumed context extension to never be a JSContextExtensionObject.

The context extension object in a 'with' context is JSContextExtensionObject iff the 'with' statement is generated from a catch block in order to extend its local scope with a variable holding exception object. This is how we differentiate 'catch' scope from 'with' scope.

Chrome bug:
http://code.google.com/p/chromium/issues/detail?id=17229

Committed: http://code.google.com/p/v8/source/detail?r=2843

[Søren Thygesen Gjesse, 2009-09-08 06:42:14]

LGTM, but please look into whether adding a new scope type ScopeTypeCatch is
feasible.

http://codereview.chromium.org/202005/diff/1/2
File src/runtime.cc (right):

http://codereview.chromium.org/202005/diff/1/2#newcode6420
Line 6420: // Current scop is either an explicit with statement or a with
statement
scop -> scope

http://codereview.chromium.org/202005/diff/1/2#newcode6422
Line 6422: // Extension object here is either a parameter of the explicit with
a parameter -> the expression

http://codereview.chromium.org/202005/diff/1/2#newcode6425
Line 6425: return ScopeTypeWith;
Maybe we should extend this with another type ScopeTypeCatch to indicate when we
have a catch scope instead of overloading the use of the with scope type. I have
not looked into whether there is a simple way find whether it is one or the
other.

[yurys, 2009-09-08 09:29:06]

http://codereview.chromium.org/202005/diff/1/2
File src/runtime.cc (right):

http://codereview.chromium.org/202005/diff/1/2#newcode6420
Line 6420: // Current scop is either an explicit with statement or a with
statement
On 2009/09/08 06:42:14, Søren Gjesse wrote:
> scop -> scope

Done.

http://codereview.chromium.org/202005/diff/1/2#newcode6422
Line 6422: // Extension object here is either a parameter of the explicit with
On 2009/09/08 06:42:14, Søren Gjesse wrote:
> a parameter -> the expression

Done.

http://codereview.chromium.org/202005/diff/1/2#newcode6425
Line 6425: return ScopeTypeWith;
On 2009/09/08 06:42:14, Søren Gjesse wrote:
> Maybe we should extend this with another type ScopeTypeCatch to indicate when
we
> have a catch scope instead of overloading the use of the with scope type. I
have
> not looked into whether there is a simple way find whether it is one or the
> other.

Done. If current context extension is a JSContextExtensionObject, the scope is a
catch block.

[Søren Thygesen Gjesse, 2009-09-08 10:08:38]

LGTM

Please ass the now scope type to
http://code.google.com/p/v8/wiki/DebuggerProtocol as well.

[yurys, 2009-09-08 10:23:31]

On 2009/09/08 10:08:38, Søren Gjesse wrote:
> LGTM
> 
> Please ass the now scope type to
> http://code.google.com/p/v8/wiki/DebuggerProtocol as well.

Done.