865774 - cpr_string.c:203:78: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]

Status: RESOLVED FIXED

(Core :: WebRTC, defect)

Description

[Daniel Holbert [:dholbert]]

GCC warning:
{
media/webrtc/signaling/src/sipcc/cpr/common/cpr_string.c:203:78: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
}
for this line:
203     MOZ_ASSERT(vsnprintf_result > 0 && vsnprintf_result < (fs->buffer_length - fs->string_length));
http://mxr.mozilla.org/mozilla-central/source/media/webrtc/signaling/src/sipcc/cpr/common/cpr_string.c#203

* vsnprintf_result is signed (it's an int)
* fs->buffer_length - fs->string_length is unsigned (both are 'size_t')

We can just static_cast vsnprintf_result to size_t, which is safe because we just checked that it's greater than 0.

Comment 1

[Daniel Holbert [:dholbert]]

er, s/static_cast/cast/ since this is a .c file

Comment 2

[Daniel Holbert [:dholbert]]

Attachment: fix v1

Comment 3

[Daniel Holbert [:dholbert]]

MXR link showing that buffer_length and string_length are size_t:

> 73 typedef struct {
> 74   char *buffer;
> 75   size_t buffer_length;
> 76   size_t string_length;
> 77 } flex_string;
http://mxr.mozilla.org/mozilla-central/source/media/webrtc/signaling/src/sipcc/cpr/include/cpr_string.h#75

Comment 4

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/d3f88b2e42f7

Comment 5

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/d3f88b2e42f7