911806 - CompileError should implement operator=

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Bill McCloskey [inactive unless it's an emergency] (:billm)]

It has some fields that are malloced, and that get freed in the destructor. Therefore it needs an operator=. This came up in bug 911204.

Comment 1

[:Benjamin Peterson]

Ooo, that's nasty. Brian's solution of bug 911204 seems good to be. Maybe it's better to just delete the copy-operator footguns.

Comment 2

[:Benjamin Peterson]

Attachment: remove copy and assignment operators of CompileError

Comment 3

[Bill McCloskey [inactive unless it's an emergency] (:billm)]

Comment on attachment 798575 [details] [diff] [review]
remove copy and assignment operators of CompileError

Review of attachment 798575 [details] [diff] [review]:
-----------------------------------------------------------------

Thanks.

::: js/src/frontend/TokenStream.h
@@ +319,5 @@
>      void throwError(JSContext *cx);
> +
> +    // CompileError owns raw allocated memory, so disable assignment and copying
> +    // for safety.
> +    void operator=(const CompileError &) MOZ_DELETE;

I'm not sure how important it is, but usually we make these private.

Comment 4

[:Benjamin Peterson]

https://hg.mozilla.org/integration/mozilla-inbound/rev/1604454f8d21

Comment 5

[Jeff Walden [:Waldo]]

private isn't strictly necessary, rather it's belt-and-suspenders.  If the compiler doesn't support = delete, then an access-check failure is a further backstop, and one that happens earlier than link failure from using an undefined function.  It doesn't catch users that are friends of the method, to be sure, but it's better than nothing for users with older compilers (actually only MSVC, now, I hear).

Comment 6

[Ed Morley [:emorley]]

https://hg.mozilla.org/mozilla-central/rev/1604454f8d21