xref: /freebsd/contrib/bmake/unit-tests/varmod-loop-varname.mk (revision 6a7405f5a6b639682cacf01e35d561411ff556aa)
1# $NetBSD: varmod-loop-varname.mk,v 1.12 2025/01/11 20:54:46 rillig Exp $
2#
3# Tests for the first part of the variable modifier ':@var@...@', which
4# contains the variable name to use during the loop.
5
6# Force the test results to be independent of the default value of this
7# setting, which is 'yes' for NetBSD's usr.bin/make but 'no' for the bmake
8# distribution and pkgsrc/devel/bmake.
9.MAKE.SAVE_DOLLARS=	yes
10
11
12# Before 2021-04-04, the name of the loop variable could be generated
13# dynamically.  There was no practical use-case for this.
14# Since var.c 1.907 from 2021-04-04, a '$' is no longer allowed in the
15# variable name.
16# expect+1: In the :@ modifier, the variable name "${:Ubar:S,b,v,}" must not contain a dollar
17.if ${:Uone two three:@${:Ubar:S,b,v,}@+${var}+@} != "+one+ +two+ +three+"
18.  error
19.else
20.  error
21.endif
22
23
24# ":::" is a very creative variable name, unlikely to occur in practice.
25# The expression ${\:\:\:} would not work since backslashes can only
26# be escaped in the modifiers, but not in the variable name, therefore
27# the extra indirection via the modifier ':U'.
28.if ${:U1 2 3:@:::@x${${:U\:\:\:}}y@} != "x1y x2y x3y"
29.  error
30.endif
31
32
33# "@@" is another creative variable name.
34.if ${:U1 2 3:@\@\@@x${@@}y@} != "x1y x2y x3y"
35.  error
36.endif
37
38
39# In extreme cases, even the backslash can be used as variable name.
40# It needs to be doubled though.
41.if ${:U1 2 3:@\\@x${${:Ux:S,x,\\,}}y@} != "x1y x2y x3y"
42.  error
43.endif
44
45
46# The variable name can technically be empty, and in this situation
47# the variable value cannot be accessed since the empty "variable"
48# is protected to always return an empty string.
49.if ${:U1 2 3:@@x${}y@} != "xy xy xy"
50.  error
51.endif
52
53
54# The :@ modifier resolves the variables from the replacement text once more
55# than expected.  In particular, it resolves _all_ variables from the scope,
56# and not only the loop variable (in this case v).
57SRCS=		source
58CFLAGS.source=	before
59ALL_CFLAGS:=	${SRCS:@src@${CFLAGS.${src}}@}	# note the ':='
60CFLAGS.source+=	after
61.if ${ALL_CFLAGS} != "before"
62.  error
63.endif
64
65
66# In the following example, the modifier ':@' expands the '$$' to '$'.  This
67# means that when the resulting expression is evaluated, these resulting '$'
68# will be interpreted as starting a subexpression.
69#
70# The d means direct reference, the i means indirect reference.
71RESOLVE=	${RES1} $${RES1}
72RES1=		1d${RES2} 1i$${RES2}
73RES2=		2d${RES3} 2i$${RES3}
74RES3=		3
75
76.if ${RESOLVE:@v@w${v}w@} != "w1d2d3w w2i3w w1i2d3 2i\${RES3}w w1d2d3 2i\${RES3} 1i\${RES2}w"
77.  error
78.endif
79
80
81# Until 2020-07-20, the variable name of the :@ modifier could end with one
82# or two dollar signs, which were silently ignored.
83# There's no point in allowing a dollar sign in that position.
84# Since var.c 1.907 from 2021-04-04, a '$' is no longer allowed in the
85# variable name.
86# expect+1: In the :@ modifier, the variable name "v$" must not contain a dollar
87.if ${1 2 3:L:@v$@($v)@} != "(1) (2) (3)"
88.  error
89.else
90.  error
91.endif
92# expect+1: In the :@ modifier, the variable name "v$$" must not contain a dollar
93.if ${1 2 3:L:@v$$@($v)@} != "() () ()"
94.  error
95.else
96.  error
97.endif
98# expect+1: In the :@ modifier, the variable name "v$$$" must not contain a dollar
99.if ${1 2 3:L:@v$$$@($v)@} != "() () ()"
100.  error
101.else
102.  error
103.endif
104
105
106# It may happen that there are nested :@ modifiers that use the same name for
107# for the loop variable.  These modifiers influence each other.
108#
109# As of 2020-10-18, the :@ modifier is implemented by actually setting a
110# variable in the scope of the expression and deleting it again after the
111# loop.  This is different from the .for loops, which substitute the
112# expression with ${:Uvalue}, leading to different unwanted side effects.
113#
114# To make the behavior more predictable, the :@ modifier should restore the
115# loop variable to the value it had before the loop.  This would result in
116# the string "1a b c1 2a b c2 3a b c3", making the two loops independent.
117.if ${:U1 2 3:@i@$i${:Ua b c:@i@$i@}${i:Uu}@} != "1a b cu 2a b cu 3a b cu"
118.  error
119.endif
120
121# During the loop, the variable is actually defined and nonempty.
122# If the loop were implemented in the same way as the .for loop, the variable
123# would be neither defined nor nonempty since all expressions of the form
124# ${var} would have been replaced with ${:Uword} before evaluating them.
125.if defined(var)
126.  error
127.endif
128.if ${:Uword:@var@${defined(var):?def:undef} ${empty(var):?empty:nonempty}@} \
129    != "def nonempty"
130.  error
131.endif
132.if defined(var)
133.  error
134.endif
135
136all: .PHONY
137