1 # $NetBSD: varmod-subst-regex.mk,v 1.3 2020/08/28 17:15:04 rillig Exp $
3 # Tests for the :C,from,to, variable modifier.
5 all: mod-regex-compile-error
9 # The variable expression expands to 4 words. Of these words, none matches
10 # the regular expression "a b" since these words don't contain any
12 .if ${:Ua b b c:C,a b,,} != "a b b c"
16 # Using the '1' modifier does not change anything. The '1' modifier just
17 # means to apply at most 1 replacement in the whole variable expression.
18 .if ${:Ua b b c:C,a b,,1} != "a b b c"
22 # The 'W' modifier treats the whole variable value as a single big word,
23 # containing whitespace. This big word matches the regular expression,
24 # therefore it gets replaced. Whitespace is preserved after replacing.
25 .if ${:Ua b b c:C,a b,,W} != " b c"
29 # The 'g' modifier does not have any effect here since each of the words
30 # contains the character 'b' a single time.
31 .if ${:Ua b b c:C,b,,g} != "a c"
35 # The first :C modifier has the 'W' modifier, which makes the whole
36 # expression a single word. The 'g' modifier then replaces all occurrences
37 # of "1 2" with "___". The 'W' modifier only applies to this single :C
38 # modifier. This is demonstrated by the :C modifier that follows. If the
39 # 'W' modifier would be preserved, only a single underscore would have been
40 # replaced with an 'x'.
41 .if ${:U1 2 3 1 2 3:C,1 2,___,Wg:C,_,x,} != "x__ 3 x__ 3"
45 # The regular expression does not match in the first word.
46 # It matches once in the second word, and the \0\0 doubles that word.
47 # In the third word, the regular expression matches as early as possible,
48 # and since the matches must not overlap, the next possible match would
49 # start at the 6, but at that point, there is only one character left,
50 # and that cannot match the regular expression "..". Therefore only the
51 # "45" is doubled in the result.
52 .if ${:U1 23 456:C,..,\0\0,} != "1 2323 45456"
56 # The modifier '1' applies the replacement at most once, across the whole
57 # variable value, no matter whether it is a single big word or many small
60 # Up to 2020-08-28, the manual page said that the modifiers '1' and 'g'
61 # were orthogonal, which was wrong.
62 .if ${:U12345 12345:C,.,\0\0,1} != "112345 12345"
66 # Multiple asterisks form an invalid regular expression. This produces an
67 # error message and (as of 2020-08-28) stops parsing in the middle of the
68 # variable expression. The unparsed part of the expression is then copied
69 # verbatim to the output, which is unexpected and can lead to strange shell
71 mod-regex-compile-error:
72 @echo $@: ${:Uword1 word2:C,****,____,g:C,word,____,:Q}.
74 # These tests generate error messages but as of 2020-08-28 just continue
75 # parsing and execution as if nothing bad had happened.
77 @echo $@:11-missing:${:U1 23 456:C,..,\1\1,:Q}
78 @echo $@:11-ok:${:U1 23 456:C,(.).,\1\1,:Q}
79 @echo $@:22-missing:${:U1 23 456:C,..,\2\2,:Q}
80 @echo $@:22-missing:${:U1 23 456:C,(.).,\2\2,:Q}
81 @echo $@:22-ok:${:U1 23 456:C,(.)(.),\2\2,:Q}
82 # The :C modifier only handles single-digit capturing groups,
83 # which is more than enough for daily use.
84 @echo $@:capture:${:UabcdefghijABCDEFGHIJrest:C,(.)(.)(.)(.)(.)(.)(.)(.)(.)(.)(.)(.)(.)(.)(.)(.)(.)(.)(.)(.),\9\8\7\6\5\4\3\2\1\0\10\11\12,}
87 @echo $@: ${UNDEF:Uvalue:C,[,,}