Platform/Platform-specific build defines

In the Gecko code we have a bunch of preprocessor conditions that help us conditionally compile code for specific platforms. These can get confusing so here is a handy-dandy table to help you keep them straight.

OS	Windows	OS X	Linux-gtk	Android		*BSD	Solaris	iOS
Product	Desktop	Desktop	Desktop	Fennec	GeckoView	Desktop	Desktop	iOS
XP_WIN	✓
XP_DARWIN		✓						✓
XP_MACOSX		✓
XP_IOS								✓
XP_UNIX		✓	✓	✓	✓	✓	✓	✓
XP_LINUX			✓	✓	✓
XP_SOLARIS							✓
ANDROID				✓	✓
MOZ_WIDGET_GTK			✓			✓	✓
MOZ_WIDGET_ANDROID				✓	✓
MOZ_WIDGET_UIKIT								✓

Prefs files

Here is a similar table, but to see which prefs get used in which product:

OS	Windows	OS X	Linux-gtk	Android		iOS
Product	Desktop	Desktop	Desktop	Fennec	GeckoView	iOS
all.js	✓	✓	✓	✓	✓	✓
firefox.js	✓	✓	✓
mobile.js				✓	??
geckoview-prefs.js					✓

Reftest conditions

Here is another table that tells you what conditions are true on various platforms for use in reftest.list conditions.

OS	Windows	OS X	Linux-gtk	Android		iOS
Product	Desktop	Desktop	Desktop	Fennec	GeckoView	iOS
Android				✓	✓
geckoview					✓
cocoaWidget		✓
gtkWidget			✓
qtWidget
winWidget	✓

Mochitest conditions

Here is another table that tells you what different condition values are on various platforms for use in mochitest.ini/a11y.ini/chrome.ini/browser.ini conditions.

OS	Windows	OS X	Linux-gtk	Android		iOS
Product	Desktop	Desktop	Desktop	Fennec	GeckoView	iOS
os	win	mac	linux	android	android	??
toolkit	windows	cocoa	gtk2 or gtk3	android	android	??
buildapp	??	??	??	mobile/android	??	??

You may also be interested in Platform/Channel-specific_build_defines