Bug 134514 – Debugger's breakpoint list should not be a Vector

• Status: RESOLVED
• Resolution: FIXED
• Component: JavaScriptCore

[Mark Lam]

The debugger currently stores breakpoint data as entries in a Vector (see BreakpointsInLine).  It also keeps a fast map look up of breakpoint IDs to the breakpoint data (see m_breakpointIDToBreakpoint).  Because a Vector can compact or reallocate it backing store, this can causes all sorts of havoc.  The m_breakpointIDToBreakpoint assumes that the breakpoint data doesn't move in memory.

The fix is to replace the BreakpointsInLine Vector with a BreakpointsList doubly linked list.

[Mark Lam]

<rdar://problem/17487061>

[Mark Lam]

Created attachment 234208 [details]
the patch

[Geoffrey Garen]

Comment on attachment 234208 [details]
the patch

View in context: https://bugs.webkit.org/attachment.cgi?id=234208&action=review

r=me

> Source/JavaScriptCore/debugger/Breakpoint.h:56
> +    Breakpoint(Breakpoint& other)

Should be const&.

[Mark Lam]

The compiler was complaining about:
Source/JavaScriptCore/debugger/Breakpoint.h:88:27: error: using the result of an assignment as a condition without parentheses [-Werror,-Wparentheses]
        while (breakpoint = removeHead())
               ~~~~~~~~~~~^~~~~~~~~~~~~~

Will add the parens.

[Mark Lam]

Created attachment 234209 [details]
updated patch to make the EWS bots happy + Geoff's suggested fix.

[Mark Lam]

Thanks.  Patch with fixes land in r170677: <http://trac.webkit.org/r170677>.