Bug 136141 – r171362 accidentally increased the size of InlineCallFrame

• Component: JavaScriptCore
• Status: RESOLVED FIXED

[Mark Lam]

r171362 increased the size of InlineCallFrame::kind to 2 bits.  This increased the size of InlineCallFrame from 72 to 80 though not intentionally.  The fix is to reduce the size of InlineCallFrame::stackOffset to 29 bits.

[Mark Lam]

Created attachment 236948 [details]
The patch

[Mark Lam]

Comment on attachment 236948 [details]
The patch

View in context: https://bugs.webkit.org/attachment.cgi?id=236948&action=review

> Source/JavaScriptCore/bytecode/CodeOrigin.h:164
> +    static const int maxStackOffset = (1 << 29) - 1;
> +    static const int minStackOffset = (~0 << 29);

Wrong limits.

[Mark Lam]

Created attachment 236949 [details]
patch 2: with correct limits

[Filip Pizlo]

Comment on attachment 236949 [details]
patch 2: with correct limits

View in context: https://bugs.webkit.org/attachment.cgi?id=236949&action=review

> Source/JavaScriptCore/bytecode/CodeOrigin.h:207
> +    void setStackOffset(signed offset)
> +    {
> +        RELEASE_ASSERT(minStackOffset <= offset && offset <= maxStackOffset);
> +        stackOffset = offset;
> +    }

Why can't this just be:

void setStackOffset(signed offset)
{
    stackOffset = offset;
    RELEASE_ASSERT(static_cast<signed>(stackOffset) == offset);
}

Then you can get rid of the minStackOffset/maxStackOffset constants.

[Mark Lam]

(In reply to comment #4)
> Why can't this just be:
> 
> void setStackOffset(signed offset)
> {
>     stackOffset = offset;
>     RELEASE_ASSERT(static_cast<signed>(stackOffset) == offset);
> }
> 
> Then you can get rid of the minStackOffset/maxStackOffset constants.

That is an excellent and superior solution.  Will fix.

[Mark Lam]

Created attachment 236964 [details]
patch 3: with better assertion.

[WebKit Commit Bot]

Comment on attachment 236964 [details]
patch 3: with better assertion.

Clearing flags on attachment: 236964

Committed r172853: <http://trac.webkit.org/changeset/172853>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.