1# $NetBSD: directive-ifdef.mk,v 1.5 2022/01/23 21:48:59 rillig Exp $ 2# 3# Tests for the .ifdef directive, which evaluates bare words by calling 4# 'defined(word)'. 5 6DEFINED= defined 7 8# There is no variable named 'UNDEF', therefore the condition evaluates to 9# false. 10.ifdef UNDEF 11. error 12.endif 13 14# There is a variable named 'DEFINED', so the condition evaluates to true. 15.ifdef DEFINED 16.else 17. error 18.endif 19 20# Since a bare word is an abbreviation for 'defined(word)', these can be 21# used to construct complex conditions. 22.ifdef UNDEF && DEFINED 23. error 24.endif 25.ifdef UNDEF || DEFINED 26.else 27. error 28.endif 29 30# It looks redundant to have a call to defined() in an .ifdef, but it's 31# possible. The '.ifdef' only affects bare words, not function calls. 32.ifdef defined(DEFINED) 33.else 34. error 35.endif 36 37# String literals are handled the same in all variants of the '.if' directive, 38# they evaluate to true if they are not empty, therefore this particular 39# example looks confusing and is thus not found in practice. 40.ifdef "" 41. error 42.else 43.endif 44 45# Whitespace counts as non-empty as well. 46.ifdef " " 47.else 48. error 49.endif 50 51all: .PHONY 52