1 1.4 rillig # $NetBSD: cond-token-var.mk,v 1.4 2020/10/24 08:46:08 rillig Exp $ 2 1.1 rillig # 3 1.2 rillig # Tests for variables in .if conditions. 4 1.1 rillig 5 1.3 rillig DEF= defined 6 1.1 rillig 7 1.3 rillig # A defined variable may appear on either side of the comparison. 8 1.3 rillig .if ${DEF} == ${DEF} 9 1.4 rillig . info ok 10 1.3 rillig .else 11 1.4 rillig . error 12 1.3 rillig .endif 13 1.3 rillig 14 1.3 rillig # A variable that appears on the left-hand side must be defined. 15 1.3 rillig .if ${UNDEF} == ${DEF} 16 1.4 rillig . error 17 1.3 rillig .endif 18 1.3 rillig 19 1.3 rillig # A variable that appears on the right-hand side must be defined. 20 1.3 rillig .if ${DEF} == ${UNDEF} 21 1.4 rillig . error 22 1.3 rillig .endif 23 1.3 rillig 24 1.3 rillig # A defined variable may appear as an expression of its own. 25 1.3 rillig .if ${DEF} 26 1.3 rillig .endif 27 1.3 rillig 28 1.3 rillig # An undefined variable generates a warning. 29 1.3 rillig .if ${UNDEF} 30 1.3 rillig .endif 31 1.3 rillig 32 1.3 rillig # The :U modifier turns an undefined variable into an ordinary expression. 33 1.3 rillig .if ${UNDEF:U} 34 1.3 rillig .endif 35