1# $NetBSD: directive-for-escape.mk,v 1.7 2021/02/15 07:58:19 rillig Exp $
2#
3# Test escaping of special characters in the iteration values of a .for loop.
4# These values get expanded later using the :U variable modifier, and this
5# escaping and unescaping must pass all characters and strings effectively
6# unmodified.
7
8.MAKEFLAGS: -df
9
10# Even though the .for loops take quotes into account when splitting the
11# string into words, the quotes don't need to be balanced, as of 2020-12-31.
12# This could be considered a bug.
13ASCII=	!"\#$$%&'()*+,-./0-9:;<=>?@A-Z[\]_^a-z{|}~
14
15# XXX: As of 2020-12-31, the '#' is not preserved in the expanded body of
16# the loop since it would not need only the escaping for the :U variable
17# modifier but also the escaping for the line-end comment.
18.for chars in ${ASCII}
19.  info ${chars}
20.endfor
21
22# As of 2020-12-31, using 2 backslashes before be '#' would treat the '#'
23# as comment character.  Using 3 backslashes doesn't help either since
24# then the situation is essentially the same as with 1 backslash.
25# This means that a '#' sign cannot be passed in the value of a .for loop
26# at all.
27ASCII.2020-12-31=	!"\\\#$$%&'()*+,-./0-9:;<=>?@A-Z[\]_^a-z{|}~
28.for chars in ${ASCII.2020-12-31}
29.  info ${chars}
30.endfor
31
32# Cover the code in for_var_len.
33#
34# XXX: It is unexpected that the variable V gets expanded in the loop body.
35# The double '$$' should prevent exactly this.  Probably nobody was
36# adventurous enough to use literal dollar signs in the values of a .for
37# loop.
38V=		value
39VALUES=		$$ $${V} $${V:=-with-modifier} $$(V) $$(V:=-with-modifier)
40.for i in ${VALUES}
41.  info $i
42.endfor
43
44# Try to cover the code for nested '{}' in for_var_len, without success.
45#
46# The value of the variable VALUES is not meant to be a variable expression.
47# Instead, it is meant to represent literal text, the only escaping mechanism
48# being that each '$' is written as '$$'.
49#
50# The .for loop splits ${VALUES} into 3 words, at the space characters, since
51# these are not escaped.
52VALUES=		$${UNDEF:U\$$\$$ {{}} end}
53# XXX: Where in the code does the '\$\$' get converted into a single '\$'?
54.for i in ${VALUES}
55.  info $i
56.endfor
57
58# Second try to cover the code for nested '{}' in for_var_len.
59#
60# XXX: It is wrong that for_var_len requires the braces to be balanced.
61# Each variable modifier has its own inconsistent way of parsing nested
62# variable expressions, braces and parentheses.  (Compare ':M', ':S', and
63# ':D' for details.)  The only sensible thing to do is therefore to let
64# Var_Parse do all the parsing work.
65VALUES=		begin<$${UNDEF:Ufallback:N{{{}}}}>end
66.for i in ${VALUES}
67.  info $i
68.endfor
69
70# A single trailing dollar doesn't happen in practice.
71# The dollar sign is correctly passed through to the body of the .for loop.
72# There, it is expanded by the .info directive, but even there a trailing
73# dollar sign is kept as-is.
74.for i in ${:U\$}
75.  info ${i}
76.endfor
77
78# As of 2020-12-31, the name of the iteration variable can even contain
79# colons, which then affects variable expressions having this exact modifier.
80# This is clearly an unintended side effect of the implementation.
81NUMBERS=	one two three
82.for NUMBERS:M*e in replaced
83.  info ${NUMBERS} ${NUMBERS:M*e}
84.endfor
85
86# As of 2020-12-31, the name of the iteration variable can contain braces,
87# which gets even more surprising than colons, since it allows to replace
88# sequences of variable expressions.  There is no practical use case for
89# this, though.
90BASENAME=	one
91EXT=		.c
92.for BASENAME}${EXT in replaced
93.  info ${BASENAME}${EXT}
94.endfor
95
96# Demonstrate the various ways to refer to the iteration variable.
97i=		outer
98i2=		two
99i,=		comma
100.for i in inner
101.  info .        $$i: $i
102.  info .      $${i}: ${i}
103.  info .   $${i:M*}: ${i:M*}
104.  info .      $$(i): $(i)
105.  info .   $$(i:M*): $(i:M*)
106.  info . $${i$${:U}}: ${i${:U}}
107.  info .    $${i\}}: ${i\}}	# XXX: unclear why ForLoop_SubstVarLong needs this
108.  info .     $${i2}: ${i2}
109.  info .     $${i,}: ${i,}
110.  info .  adjacent: $i${i}${i:M*}$i
111.endfor
112
113all:
114