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		iOS
Product	Desktop	B2G	Desktop	B2G	Desktop	B2G	Mulet	Fennec	B2G	iOS
XP_WIN	✓	✓
XP_DARWIN			✓	✓						✓
XP_MACOSX			✓	✓
XP_IOS										✓
XP_UNIX			✓	✓	✓	✓	✓	✓	✓	✓
XP_LINUX					✓	✓	✓	✓	✓
ANDROID								✓	✓
MOZ_B2G		✓		✓		✓	✓		✓
MOZ_MULET							✓
MOZ_WIDGET_GTK					✓	✓	✓
MOZ_WIDGET_ANDROID								✓
MOZ_WIDGET_GONK									✓
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	B2G	Desktop	B2G	Desktop	B2G	Mulet	Fennec	B2G	iOS
all.js	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓
firefox.js	✓		✓		✓		✓
mobile.js								✓
b2g.js		✓		✓		✓	✓		✓
mulet.js							✓

WARNING: Until bug 1174234 is resolved firefox.js prefs will override mulet.js prefs on Mulet.

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	B2G	Desktop	B2G	Desktop	B2G	Mulet	Fennec	B2G	iOS
B2G									✓
B2GDT		✓		✓		✓
Android								✓
cocoaWidget			✓	✓
gtkWidget					✓	✓	✓
qtWidget
winWidget	✓	✓
Mulet							✓

You may also be interested in Platform/Channel-specific_build_defines