1# $NetBSD: varmod-remember.mk,v 1.9 2023/02/09 22:21:57 rillig Exp $
2#
3# Tests for the :_ modifier, which saves the current expression value
4# in the _ variable or another, to be used later again.
5
6
7# The ':_' modifier is typically used in situations where the value of an
8# expression is needed at the same time as a sequence of numbers.  In these
9# cases, the value of the expression is saved in the temporary variable '_',
10# from where it is taken later in the same expression.
11ABC=	${A B C:L:_:range:@i@$i=${_:[$i]}@}
12DEF=	${D E F:L:_:range:@i@$i=${_:[$i]}@}
13GHI=	${G H I:L:_:range:@i@$i=${_:[$i]}@}
14
15ABC.global:=	${ABC}		# is evaluated in the global scope
16.if ${ABC.global} != "1=A 2=B 3=C"
17.  error
18.endif
19
20.if ${DEF} != "1=D 2=E 3=F"	# is evaluated in the command line scope
21.  error
22.endif
23
24# Before var.c 1.1040 from 2023-02-09, the temporary variable '_' was placed
25# in the scope of the current evaluation, which meant that after the first
26# ':_' modifier had been evaluated in command line scope, all further
27# evaluations in global scope could not overwrite the variable '_' anymore,
28# as the command line scope takes precedence over the global scope.
29# The expression ${GHI} therefore evaluated to '1=D 2=E 3=F', reusing the
30# value of '_' from the previous evaluation in command line scope.
31GHI.global:=	${GHI}		# is evaluated in the global scope
32.if ${GHI.global} != "1=G 2=H 3=I"
33.  error
34.endif
35
36
37# In the parameterized form, having the variable name on the right side of
38# the = assignment operator looks confusing.  In almost all other situations,
39# the variable name is on the left-hand side of the = operator, therefore
40# '_=SAVED' looks like it would copy 'SAVED' to '_'.  Luckily, this modifier
41# is only rarely needed.
42.if ${1 2 3:L:@var@${var:_=SAVED:}@} != "1 2 3"
43.  error
44.elif ${SAVED} != "3"
45.  error
46.endif
47
48
49# The ':_' modifier takes a variable name as optional argument.  Before var.c
50# 1.867 from 2021-03-14, this variable name could refer to other variables,
51# such as in 'VAR.$p'.  It was not possible to refer to 'VAR.${param}' though,
52# as that form caused a parse error.  The cause for the parse error in
53# '${...:_=VAR.${param}}' is that the variable name is parsed in an ad-hoc
54# manner, stopping at the first ':', ')' or '}', without taking any nested
55# expressions into account.  Due to this inconsistency that short expressions
56# are possible but long expressions aren't, the name of the temporary variable
57# is no longer expanded.
58#
59# TODO: Warn about the unusual variable name '$S'.
60S=	INDIRECT_VARNAME
61.if ${value:L:@var@${var:_=$S}@} != "value"
62.  error
63.elif defined(INDIRECT_VARNAME)
64.  error
65.endif
66
67
68# When a variable using ':_' refers to another variable that also uses ':_',
69# the value of the temporary variable '_' from the inner expression leaks into
70# the evaluation of the outer expression.  If the expressions were evaluated
71# independently, the last word of the result would be outer_='outer' instead.
72INNER=	${inner:L:_:@i@$i inner_='$_'@}
73OUTER=	${outer:L:_:@o@$o ${INNER} outer_='$_'@}
74.if ${OUTER} != "outer inner inner_='inner' outer_='inner'"
75.endif
76
77
78all:
79