Bug 61014 – Most built-in properties are not deletable

• Component: JavaScriptCore
• Status: RESOLVED FIXED

[Geoffrey Garen]

Our static hash tables don't allow for deleting properties. This is the cause of a bunch of expected failures in LayoutTests/sputnik.

For example:

delete Date.UTC // true
Date.UTC // function UTC() { [native code] }

[Alexey Proskuryakov]

See also: bug 55034 (global object's Math property should be deletable)

[Gavin Barraclough]

Created attachment 111100 [details]
The patch

[WebKit Review Bot]

Attachment 111100 [details] did not pass style-queue:

Failed to run "['Tools/Scripts/check-webkit-style', '--diff-files', u'LayoutTests/ChangeLog', u'LayoutTests/fast..." exit_code: 1

Source/JavaScriptCore/runtime/JSObject.h:77:  The parameter name "exec" adds no information, so it should be removed.  [readability/parameter_name] [5]
Source/JavaScriptCore/runtime/JSObject.h:77:  The parameter name "entry" adds no information, so it should be removed.  [readability/parameter_name] [5]
Source/JavaScriptCore/runtime/JSObject.h:77:  The parameter name "slot" adds no information, so it should be removed.  [readability/parameter_name] [5]
Source/JavaScriptCore/runtime/JSObject.h:214:  The parameter name "exec" adds no information, so it should be removed.  [readability/parameter_name] [5]
Total errors found: 4 in 65 files


If any of these errors are false positives, please file a bug against check-webkit-style.

[Filip Pizlo]

Comment on attachment 111100 [details]
The patch

View in context: https://bugs.webkit.org/attachment.cgi?id=111100&action=review

> Source/JavaScriptCore/runtime/JSObject.h:214
> +        void reifyStaticFunctions(ExecState* exec);

Rename to reifyStaticFunctionsForDelete().

> Source/JavaScriptCore/runtime/Structure.h:296
> +        // 7 free bits

Maybe delete this comment?  It's probably wrong and unlikely to be useful.

[Gavin Barraclough]

The problem for static functions is fixed in r97536.

A couple of custom getters might still have an issue, we should look into this.

[Gavin Barraclough]

Comment on attachment 111100 [details]
The patch

clearing review flag on landed patch.

[Ryosuke Niwa]

It seems like this patch broke Windows build:
http://build.webkit.org/builders/Windows%20Debug%20%28Build%29/builds/40962/steps/compile-webkit/logs/stdio

[Erik Corry]

This looks like a dupe of https://bugs.webkit.org/show_bug.cgi?id=25527

[Adam Roben (:aroben)]

Attempted to fix the Windows build in http://trac.webkit.org/changeset/97610

[Adam Roben (:aroben)]

…and r97615

[Adam Roben (:aroben)]

…and r97620

[Mark S. Miller]

At https://bugs.webkit.org/show_bug.cgi?id=70207#c2 Gavin confirms this issue is related to that one.

[Gavin Barraclough]

No sure why I didn't close this; not aware of any other specific issues, if any other properties that should be deletable are not, that should warrant separate bug reports.  Fixed in r97536.

[Gavin Barraclough]

*** Bug 66473 has been marked as a duplicate of this bug. ***