866317 - GCC build warning: ccsip_debug.c: zero-length gnu_printf format string

Status: RESOLVED FIXED

(Core :: WebRTC, defect)

Description

[Daniel Holbert [:dholbert]]

{
media/webrtc/signaling/src/sipcc/core/sipstack/ccsip_debug.c: zero-length gnu_printf format string
}

This was introduced yesterday from this cset:
http://hg.mozilla.org/mozilla-central/diff/9defb9661f84/media/webrtc/signaling/src/sipcc/core/sipstack/ccsip_debug.c#l1.80
which replaced
 buginf_msg("\n");
with
 CSFLogDebug("sipstack", "");

Based on the other replacements there, it looks like we should be passing "\n" as the format-string there, to preserve the old logging behavior.

Alternately, if we don't want to pass \n because we already get a newline somewhere under the hood, we can pass "%s", "" -- i.e. use %s as the non-empty format string, and pass "" to make it end up evaluating to the empty string.

Comment 1

[Daniel Holbert [:dholbert]]

Attachment: fix: use ["%s", ""] instead of [""]

This should preserve the existing behavior, and it silences the warning.

Comment 2

[Daniel Holbert [:dholbert]]

(In reply to Daniel Holbert [:dholbert] from comment #0)
> Alternately, if we don't want to pass \n because we already get a newline
> somewhere under the hood, we can pass "%s", ""

(This is what I went with, because AFAICT we do get a newline under the hood -- this ends up translating into a call to CSFLogV, which prints a newline, as shown here: 
https://mxr.mozilla.org/mozilla-central/source/media/webrtc/signaling/src/common/browser_logging/CSFLog.cpp#203
)

Comment 3

[Daniel Holbert [:dholbert]]

er, wrong line highlighted in that MXR link -- I meant:
https://mxr.mozilla.org/mozilla-central/source/media/webrtc/signaling/src/common/browser_logging/CSFLog.cpp?mark=128-128#125

Comment 4

[Adam Roach [:abr]]

I think the offending line can just be removed. The prospect of a blank line really only made sense in the original logging environment that is long, long gone. Thanks.

Comment 5

[Daniel Holbert [:dholbert]]

OK, I'll post a new patch that just nukes the line.

Comment 6

[Daniel Holbert [:dholbert]]

Attachment: fix v2: just drop the line

Comment 7

[Daniel Holbert [:dholbert]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/47e1247d776e

Comment 8

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/47e1247d776e