832554 - Fix android build warnings for -Wunused-function (e.g. gfxFontMissingGlyphs.cpp:148:1: warning: 'void DrawHexChar(gfxContext*, const gfxPoint&, uint32_t)' defined but not used)

Status: RESOLVED FIXED

(Core :: Graphics: Text, defect)

Description

[Daniel Holbert [:dholbert]]

Build warning on Android:
{
gfx/thebes/gfxFontMissingGlyphs.cpp:148:1: warning: 'void DrawHexChar(gfxContext*, const gfxPoint&, uint32_t)' defined but not used [-Wunused-function]
}

This function is only used in an "#ifndef MOZ_GFX_OPTIMIZE_MOBILE" chunk, ever since this cset...
https://hg.mozilla.org/mozilla-central/rev/082875fdb725
...so we should make the function-definition #ifndef MOZ_GFX_OPTIMIZE_MOBILE as well.

Comment 1

[Daniel Holbert [:dholbert]]

Attachment: fix v1

Comment 2

[Daniel Holbert [:dholbert]]

I found two more instances of this -- that is, two more static helper functions in the same directory that are currently defined unconditionally but aren't called if ANDROID or MOZ_GFX_OPTIMIZE_MOBILE are defined.

Bundling those into this bug, as well. The three warnings (including the one from comment 0) are:
{
../../../gfx/thebes/gfxFontMissingGlyphs.cpp:148:1: warning: 'void DrawHexChar(gfxContext*, const gfxPoint&, uint32_t)' defined but not used [-Wunused-function]

../../../gfx/thebes/gfxFT2Fonts.cpp:43:1: warning: 'PRLogModuleInfo* GetFontLog()' defined but not used [-Wunused-function]

../../../gfx/thebes/gfxUtils.cpp:216:1: warning: 'already_AddRefed<gfxDrawable> CreateSamplingRestrictedDrawable(gfxDrawable*, gfxContext*, const gfxMatrix&, const gfxRect&, const gfxRect&, gfxASurface::gfxImageFormat)' defined but not used [-Wunused-function]
}

Comment 3

[Daniel Holbert [:dholbert]]

Attachment: fix v2

Comment 4

[Benoit Girard (:BenWa)]

Comment on attachment 704663 [details] [diff] [review]
fix v2

This is the kind of stuff I would rather just silence the compiler. It should be optimized out of the compilation unit at build time.

But I don't object to this change.

Comment 5

[Daniel Holbert [:dholbert]]

(In reply to Benoit Girard (:BenWa) from comment #4)
> This is the kind of stuff I would rather just silence the compiler

Well -- in code without #ifdefs, this warning would be telling you "Here's a static function that's never called, anywhere. Either you meant to call it and forgot (BUG!), or it's dead code. (not a big problem, but worth cleaning up)"

That's a very useful thing for the compiler to tell you about.

(Unfortunately, since the compiler sees code after #ifdef-processing has happened, I'm not sure it can distinguish that situation from this situation where there are a bunch of platform-specific #ifdefs enabling/disabling various chunks of code.)

Comment 6

[Daniel Holbert [:dholbert]]

and: thanks for the quick review turnaround! :)

Comment 7

[Daniel Holbert [:dholbert]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/33e8b01d811a

Comment 8

[(no longer active)]

https://hg.mozilla.org/mozilla-central/rev/33e8b01d811a