blob: c6471756a3dd67dce993472267af8f70589dbd2a (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
|
# $NetBSD: cond-token-var.mk,v 1.8 2023/11/19 21:47:52 rillig Exp $
#
# Tests for expressions in .if conditions.
#
# Note the fine distinction between a variable and an expression.
# A variable has a name and a value. To access the value, one writes an
# expression of the form ${VAR}. This is a simple
# expression. Expressions can get more complicated by adding
# variable modifiers such as in ${VAR:Mpattern}.
#
# XXX: Strictly speaking, variable modifiers should be called expression
# modifiers instead since they only modify the expression, not the variable.
# Well, except for the assignment modifiers, these do indeed change the value
# of the variable.
DEF= defined
# A defined variable may appear on either side of the comparison.
.if ${DEF} == ${DEF}
# expect+1: ok
. info ok
.else
. error
.endif
# A variable that appears on the left-hand side must be defined.
# expect+1: Malformed conditional (${UNDEF} == ${DEF})
.if ${UNDEF} == ${DEF}
. error
.endif
# A variable that appears on the right-hand side must be defined.
# expect+1: Malformed conditional (${DEF} == ${UNDEF})
.if ${DEF} == ${UNDEF}
. error
.endif
# A defined variable may appear as an expression of its own.
.if ${DEF}
.endif
# An undefined variable on its own generates a parse error.
# expect+1: Malformed conditional (${UNDEF})
.if ${UNDEF}
.endif
# The :U modifier turns an undefined expression into a defined expression.
# Since the expression is defined now, it doesn't generate any parse error.
.if ${UNDEF:U}
.endif
# If the value of the expression is a number, it is compared against
# zero.
.if ${:U0}
. error
.endif
.if !${:U1}
. error
.endif
# If the value of the expression is not a number, any non-empty
# value evaluates to true, even if there is only whitespace.
.if ${:U}
. error
.endif
.if !${:U }
. error
.endif
.if !${:Uanything}
. error
.endif
|
