822804 - GfxDriverInfo.h:156: warning: comparison between signed and unsigned integer expressions

Status: RESOLVED FIXED

(Core :: Graphics, defect)

Description

[Daniel Holbert [:dholbert]]

Just hit these build warnings while building B2G:
{
In file included from gecko/widget/xpwidgets/GfxDriverInfo.cpp:7:

gecko/widget/xpwidgets/GfxDriverInfo.h: In function 'bool mozilla::widget::SplitDriverVersion(const char*, char*, char*, char*, char*)':

gecko/widget/xpwidgets/GfxDriverInfo.h:156: warning: comparison between signed and unsigned integer expressions

gecko/widget/xpwidgets/GfxDriverInfo.h:179: warning: comparison between signed and unsigned integer expressions
}

This is for the variable "int destIdx", which is initialized to 0 and then incremented from there (and never modified in any other way).  Looks like it can just be an unsigned variable.

Comment 1

[Daniel Holbert [:dholbert]]

Attachment: fix

This fixes it.

Technically we only need destIdx to be unsigned to fix the warning -- but for consistency, I tweaked destPos, too, since it's used the same way (set to 0, incremented from there) and is declared right next to destIdx.

Here's the chunk of code in MXR, for reference:
https://mxr.mozilla.org/mozilla-central/source/widget/xpwidgets/GfxDriverInfo.h#152

Comment 2

[Daniel Holbert [:dholbert]]

(I'm pretty sure "len" and "i" can also be unsigned, or perhaps size_t, because strlen returns size_t.  I'm happy to change those, too, but I left them as-is for now to keep the patch minimal, & since "len" and "i" aren't not causing problems.)

Comment 3

[Daniel Holbert [:dholbert]]

er s/aren't not/aren't/ :)

Comment 4

[Daniel Holbert [:dholbert]]

https://hg.mozilla.org/mozilla-central/rev/84320dffec6e