varmod-sysv.mk revision 1.23 1 # $NetBSD: varmod-sysv.mk,v 1.23 2025/03/29 11:51:54 rillig Exp $
2 #
3 # Tests for the variable modifier ':from=to', which replaces the suffix
4 # "from" with "to". It can also use '%' as a wildcard.
5 #
6 # This modifier is applied when the other modifiers don't match exactly.
7 #
8 # See ApplyModifier_SysV.
9
10 # A typical use case for the modifier ':from=to' is conversion of filename
11 # extensions.
12 .if ${src.c:L:.c=.o} != "src.o"
13 . error
14 .endif
15
16 # The modifier applies to each word on its own.
17 .if ${one.c two.c three.c:L:.c=.o} != "one.o two.o three.o"
18 . error
19 .endif
20
21 # Words that don't match the pattern are passed unmodified.
22 .if ${src.c src.h:L:.c=.o} != "src.o src.h"
23 . error
24 .endif
25
26 # The modifier ':from=to' is therefore often combined with the modifier ':M'.
27 .if ${src.c src.h:L:M*.c:.c=.o} != "src.o"
28 . error
29 .endif
30
31 # Another use case for the modifier ':from=to' is to append a suffix to each
32 # word. In this case, the "from" string is empty, therefore it always
33 # matches. The same effect can be achieved with the modifier ':S,$,teen,'.
34 .if ${four six seven nine:L:=teen} != "fourteen sixteen seventeen nineteen"
35 . error
36 .endif
37
38 # The modifier ':from=to' can also be used to surround each word by strings.
39 # It might be tempting to use this for enclosing a string in quotes for the
40 # shell, but that's the job of the modifier ':Q'.
41 .if ${one two three:L:%=(%)} != "(one) (two) (three)"
42 . error
43 .endif
44
45 # When the modifier ':from=to' is parsed, it lasts until the closing brace
46 # or parenthesis. The ':Q' in the below expression may look like a modifier
47 # but it isn't. It is part of the replacement string.
48 .if ${a b c d e:L:%a=x:Q} != "x:Q b c d e"
49 . error
50 .endif
51
52 # In the modifier ':from=to', both parts can contain expressions.
53 .if ${one two:L:${:Uone}=${:U1}} != "1 two"
54 . error
55 .endif
56
57 # In the modifier ':from=to', the "from" part is expanded exactly once.
58 .if ${:U\$ \$\$ \$\$\$\$:${:U\$\$\$\$}=4} != "\$ \$\$ 4"
59 . error
60 .endif
61
62 # In the modifier ':from=to', the "to" part is expanded exactly twice.
63 # XXX: The right-hand side should be expanded only once.
64 # XXX: It's hard to get the escaping correct here, and to read that.
65 # XXX: It's not intuitive why the closing brace must be escaped but not
66 # the opening brace.
67 .if ${:U1 2 4:4=${:Uonce\${\:Utwice\}}} != "1 2 oncetwice"
68 . error
69 .endif
70
71 # The replacement string can contain spaces, thereby changing the number
72 # of words in the expression.
73 .if ${In:L:%=% ${:Uthe Sun}} != "In the Sun"
74 . error
75 .endif
76
77 # If the variable value is empty, it is debatable whether it consists of a
78 # single empty word, or no word at all. The modifier ':from=to' treats it as
79 # no word at all.
80 #
81 # See SysVMatch, which doesn't handle w_len == p_len specially.
82 .if ${:L:=suffix} != ""
83 . error
84 .endif
85
86 # If the variable value is empty, it is debatable whether it consists of a
87 # single empty word (before 2020-05-06), or no word at all (since 2020-05-06).
88 #
89 # See SysVMatch, percent != NULL && w[0] == '\0'.
90 .if ${:L:%=suffix} != ""
91 . error
92 .endif
93
94 # Before 2020-07-19, an ampersand could be used in the replacement part
95 # of a SysV substitution modifier, and it was replaced with the whole match,
96 # just like in the modifier ':S'.
97 #
98 # This was probably a copy-and-paste mistake since the code for the SysV
99 # modifier looked a lot like the code for the modifiers ':S' and ':C'.
100 # The ampersand is not mentioned in the manual page.
101 .if ${a.bcd.e:L:a.%=%} != "bcd.e"
102 . error
103 .endif
104 # Before 2020-07-19, the result of the expression was "a.bcd.e".
105 .if ${a.bcd.e:L:a.%=&} != "&"
106 . error
107 .endif
108
109 # Before 2020-07-20, when a SysV modifier was parsed, a single dollar
110 # before the '=' was parsed (but not interpreted) as an anchor.
111 # Parsing something without then evaluating it accordingly doesn't make
112 # sense, so this has been fixed.
113 .if ${value:L:e$=x} != "value"
114 . error
115 .endif
116 # Before 2020-07-20, the modifier ':e$=x' was parsed as having a left-hand
117 # side 'e' and a right-hand side 'x'. The dollar was parsed (but not
118 # interpreted) as 'anchor at the end'. Therefore the modifier was equivalent
119 # to ':e=x', which doesn't match the string "value$". Therefore the whole
120 # expression evaluated to "value$".
121 .if ${${:Uvalue\$}:L:e$=x} != "valux"
122 . error
123 .endif
124 .if ${value:L:e=x} != "valux"
125 . error
126 .endif
127
128 # Words that don't match are copied unmodified.
129 .if ${:Ufile.c file.h:%.c=%.cpp} != "file.cpp file.h"
130 . error
131 .endif
132
133 # The % placeholder can be anywhere in the string, it doesn't have to be at
134 # the beginning of the pattern.
135 .if ${:Ufile.c other.c:file.%=renamed.%} != "renamed.c other.c"
136 . error
137 .endif
138
139 # It's also possible to modify each word by replacing the prefix and adding
140 # a suffix.
141 .if ${one two:L:o%=a%w} != "anew two"
142 . error
143 .endif
144
145 # Each word gets the suffix "X" appended.
146 .if ${one two:L:=X} != "oneX twoX"
147 . error
148 .endif
149
150 # The suffix "o" is replaced with "X".
151 .if ${one two:L:o=X} != "one twX"
152 . error
153 .endif
154
155 # The suffix "o" is replaced with nothing.
156 .if ${one two:L:o=} != "one tw"
157 . error
158 .endif
159
160 # The suffix "o" is replaced with a literal percent. The percent is only
161 # a wildcard when it appears on the left-hand side.
162 .if ${one two:L:o=%} != "one tw%"
163 . error
164 .endif
165
166 # Each word with the suffix "o" is replaced with "X". The percent is a
167 # wildcard even though the right-hand side does not contain another percent.
168 .if ${one two:L:%o=X} != "one X"
169 . error
170 .endif
171
172 # Each word with the prefix "o" is replaced with "X". The percent is a
173 # wildcard even though the right-hand side does not contain another percent.
174 .if ${one two:L:o%=X} != "X two"
175 . error
176 .endif
177
178 # For each word with the prefix "o" and the suffix "e", the whole word is
179 # replaced with "X".
180 .if ${one two oe oxen:L:o%e=X} != "X two X oxen"
181 . error
182 .endif
183
184 # Only the first '%' is the wildcard.
185 .if ${one two o%e other%e:L:o%%e=X} != "one two X X"
186 . error
187 .endif
188
189 # In the replacement, only the first '%' is the placeholder, all others
190 # are literal percent characters.
191 .if ${one two:L:%=%%} != "one% two%"
192 . error
193 .endif
194
195 # In the word "one", only a prefix of the pattern suffix "nes" matches,
196 # the whole word is too short. Therefore it doesn't match.
197 .if ${one two:L:%nes=%xxx} != "one two"
198 . error
199 .endif
200
201 # The modifier ':from=to' can be used to replace both the prefix and a suffix
202 # of a word with other strings. This is not possible with a single :S
203 # modifier, and using a :C modifier for the same task looks more complicated
204 # in many cases.
205 .if ${prefix-middle-suffix:L:prefix-%-suffix=p-%-s} != "p-middle-s"
206 . error
207 .endif
208
209 # This is not a SysV modifier since the nested expression expands
210 # to an empty string. The '=' in it should be irrelevant during parsing.
211 # XXX: As of 2024-06-30, this expression generates an "Unfinished modifier"
212 # error, while the correct error message would be "Unknown modifier" since
213 # there is no modifier named "fromto".
214 # expect+1: Unfinished modifier after "from${:D=}to}", expecting "="
215 .if ${word216:L:from${:D=}to}
216 . error
217 .endif
218
219 # XXX: This specially constructed case demonstrates that the SysV modifier
220 # lasts longer than expected. The whole expression initially has the value
221 # "fromto}...". The next modifier is a SysV modifier. ApplyModifier_SysV
222 # parses the modifier as "from${:D=}to", ending at the '}'. Next, the two
223 # parts of the modifier are parsed using ParseModifierPart, which scans
224 # differently, properly handling nested expressions. The two parts
225 # are now "fromto}..." and "replaced".
226 .if "${:Ufromto\}...:from${:D=}to}...=replaced}" != "replaced"
227 . error
228 .endif
229
230 # As of 2020-10-06, the right-hand side of the SysV modifier is expanded
231 # twice. The first expansion happens in ApplyModifier_SysV, where the
232 # modifier is split into its two parts. The second expansion happens
233 # when each word is replaced in ModifyWord_SYSVSubst.
234 # XXX: This is unexpected. Add more test case to demonstrate the effects
235 # of removing one of the expansions.
236 VALUE= value
237 INDIRECT= 1:${VALUE} 2:$${VALUE} 4:$$$${VALUE}
238 .if ${x:L:x=${INDIRECT}} != "1:value 2:value 4:\${VALUE}"
239 . error
240 .endif
241
242 # Test all relevant combinations of prefix, '%' and suffix in both the pattern
243 # and the replacement.
244 !=1>&2 printf '%-24s %-24s %-24s\n' 'word' 'modifier' 'result'
245 .for from in '' ffix % pre% %ffix pre%ffix
246 . for to in '' NS % %NS NPre% NPre%NS
247 . for word in '' suffix prefix pre-middle-suffix
248 . for mod in ${from:N''}=${to:N''}
249 !=1>&2 printf '%-24s %-24s "%s"\n' ''${word:Q} ''${mod:Q} ''${word:N'':${mod}:Q}
250 . endfor
251 . endfor
252 . endfor
253 .endfor
254
255
256 # The error case of an unfinished ':from=to' modifier after the '=' requires
257 # an expression that is missing the closing '}'.
258 # expect+1: Unfinished modifier after "$(})", expecting "}"
259 .if ${error:L:from=$(})
260 .endif
261
262
263 all:
264