208868 - New nsCSSDataBlock.cpp produces "may be used uninitialized" warning.

Status: VERIFIED FIXED

(Core :: CSS Parsing and Computation, defect)

Description

[Aleksey Nogin]

Brad Tbox shows a new "may be used uninitialized" warning:

+content/html/style/src/nsCSSDataBlock.cpp:349
+ `void*copy' might be used uninitialized in this function

The warning was introduced by the bug 125246 check-in. In comes from a
"notreached" default case in a switch statement and is trivial to fix (patch
coming up in a moment).

Comment 1

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

I'm curious to see what the "simple" fix is.  I'd rather not add real code
that's never used.  (I almost used gotos here instead of the inner switch.)

Comment 2

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

(I guess one could put the unreachable default case first, and without a |break;|.)

Comment 3

[Aleksey Nogin]

Attachment: Initialize the variable in the "default" switch case.

Comment 4

[Aleksey Nogin]

Comment on attachment 125265 [details] [diff] [review]
Initialize the variable in the "default" switch case.

Is this reasonable? Thanks!

Comment 5

[Brendan Eich [:brendan]]

We shouldn't necessarily add code size and runtime cost.  If gcc is failing to
do enough flow analysis to determine that the default: case is never reached,
then it might be better to hold out for a gcc fix, and live with the warning.

/be

Comment 6

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

Attachment: since people annoy me when I produce warnings, replace with gotos

Comment 7

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

Comment on attachment 125270 [details] [diff] [review]
since people annoy me when I produce warnings, replace with gotos

Actually, this increases code size, probably since gcc doesn't optimize it as
well...

Comment 8

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

Attachment: patch

Comment 9

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

Fix by checkin of bug 208872 to trunk, 2003-06-10 15:08 -0700.

Comment 10

[Aleksey Nogin]

V, warning disappeared from brad TBox