A simple fix of issue http://code.google.com/p/chromium/issues/detail?id=3285...

A simple fix of issue http://code.google.com/p/chromium/issues/detail?id=3285

NPN_Construct allows a NPObject to be called as a construct. For example, the test case

var s = new app.Packages.java.lang.Integer(5);

app.Packages.java.lang.Integer is a NPObject, and it implements NPN_Construct.

This fix allows a JSObject created by an API function be called as a construct if it can be called
as a function. This is done by generating the same code for
var s = new app.Packages.java.lang.Integer(5); as
var s = app.Packages.java.lang.Integer(5);

and the caller handles both case correctly. A more sophiscated fix is to one extra JSConstructCall
frame and allow CallAsConstructor in Builtin::HandleApiCallAsFunction.

This change itself shouldn't affect the semantic of normal case such as:

var a = {};
var s = new a();

A TypeError exception will be thrown in CALL_NON_FUNCTION (runtime.js).

Another part of fix is in the binding code, V8NPObject, which makes NPN_InvokeDefault or NPN_Construct
call depending on which function is available.

[Feng Qian, 2009-04-27 22:17:40]

Mads,

Can you take a look this fix?

[Mads Ager (chromium), 2009-04-28 10:50:15]

LGTM

This is a hack and we should revisit it, but as a temporary solution to make the
NPObject construct calls work, I'm ok with this.

http://codereview.chromium.org/60035/diff/1/3
File src/builtins-ia32.cc (right):

http://codereview.chromium.org/60035/diff/1/3#newcode309
Line 309: __ xor_(ebx, Operand(ebx));
Add a comment that this is setting the arguments count to zero?

http://codereview.chromium.org/60035/diff/1/2
File test/cctest/test-api.cc (left):

http://codereview.chromium.org/60035/diff/1/2#oldcode4561
Line 4561: // Try something that will cause an exception: Call the object as a
Please add a test case for the intended behavior of construct calls.

[Kevin Millikin (Chromium), 2009-04-28 11:48:43]

http://codereview.chromium.org/60035/diff/1/3
File src/builtins-ia32.cc (right):

http://codereview.chromium.org/60035/diff/1/3#newcode309
Line 309: __ xor_(ebx, Operand(ebx));
Setting the expected number of arguments (not changing eax).  You can also write
Set(ebx, Immediate(0)).

[Feng Qian, 2009-04-30 23:26:15]

I lost my client already, reconstructing the patch.

http://codereview.chromium.org/60035/diff/1/2
File test/cctest/test-api.cc (left):

http://codereview.chromium.org/60035/diff/1/2#oldcode4561
Line 4561: // Try something that will cause an exception: Call the object as a
This needs to be tested by a layout test. V8 treats construct call and function
call as the same if an object can be called as the function.

Like I said in TODO: V8 needs to pass different flags to the callback function,
or make two different API for callAsFunction and callAsConstruct.

On 2009/04/28 10:50:15, Mads Ager wrote:
> Please add a test case for the intended behavior of construct calls.