modmisc.mk revision 1.22 1 # $Id: modmisc.mk,v 1.22 2020/07/25 20:35:35 rillig Exp $
2 #
3 # miscellaneous modifier tests
4
5 # do not put any dirs in this list which exist on some
6 # but not all target systems - an exists() check is below.
7 path=:/bin:/tmp::/:.:/no/such/dir:.
8 # strip cwd from path.
9 MOD_NODOT=S/:/ /g:N.:ts:
10 # and decorate, note that $'s need to be doubled. Also note that
11 # the modifier_variable can be used with other modifiers.
12 MOD_NODOTX=S/:/ /g:N.:@d@'$$d'@
13 # another mod - pretend it is more interesting
14 MOD_HOMES=S,/home/,/homes/,
15 MOD_OPT=@d@$${exists($$d):?$$d:$${d:S,/usr,/opt,}}@
16 MOD_SEP=S,:, ,g
17
18 all: modvar modvarloop modsysv mod-HTE emptyvar undefvar
19 all: mod-S mod-C mod-at-varname mod-at-resolve mod-at-dollar
20 all: mod-subst-dollar mod-loop-dollar
21 all: mod-C-limits
22 all: mod-C-errors
23 all: mod-assign
24 all: mod-assign-nested
25 all: mod-tu-space
26 all: mod-Q
27 all: mod-break-many-words
28
29 modsysv:
30 @echo "The answer is ${libfoo.a:L:libfoo.a=42}"
31
32 modvar:
33 @echo "path='${path}'"
34 @echo "path='${path:${MOD_NODOT}}'"
35 @echo "path='${path:S,home,homes,:${MOD_NODOT}}'"
36 @echo "path=${path:${MOD_NODOTX}:ts:}"
37 @echo "path=${path:${MOD_HOMES}:${MOD_NODOTX}:ts:}"
38
39 .for d in ${path:${MOD_SEP}:N.} /usr/xbin
40 path_$d?= ${d:${MOD_OPT}:${MOD_HOMES}}/
41 paths+= ${d:${MOD_OPT}:${MOD_HOMES}}
42 .endfor
43
44 modvarloop:
45 @echo "path_/usr/xbin=${path_/usr/xbin}"
46 @echo "paths=${paths}"
47 @echo "PATHS=${paths:tu}"
48
49 PATHNAMES= a/b/c def a.b.c a.b/c a a.a .gitignore a a.a
50 mod-HTE:
51 @echo "dirname of '"${PATHNAMES:Q}"' is '"${PATHNAMES:H:Q}"'"
52 @echo "basename of '"${PATHNAMES:Q}"' is '"${PATHNAMES:T:Q}"'"
53 @echo "suffix of '"${PATHNAMES:Q}"' is '"${PATHNAMES:E:Q}"'"
54 @echo "root of '"${PATHNAMES:Q}"' is '"${PATHNAMES:R:Q}"'"
55
56 # When a modifier is applied to the "" variable, the result is discarded.
57 emptyvar:
58 @echo S:${:S,^$,empty,}
59 @echo C:${:C,^$,empty,}
60 @echo @:${:@var@${var}@}
61
62 # The :U modifier turns even the "" variable into something that has a value.
63 # The resulting variable is empty, but is still considered to contain a
64 # single empty word. This word can be accessed by the :S and :C modifiers,
65 # but not by the :@ modifier since it explicitly skips empty words.
66 undefvar:
67 @echo S:${:U:S,^$,empty,}
68 @echo C:${:U:C,^$,empty,}
69 @echo @:${:U:@var@empty@}
70
71 mod-S:
72 @echo $@:
73 @echo :${:Ua b b c:S,a b,,:Q}:
74 @echo :${:Ua b b c:S,a b,,1:Q}:
75 @echo :${:Ua b b c:S,a b,,W:Q}:
76 @echo :${:Ua b b c:S,b,,g:Q}:
77 @echo :${:U1 2 3 1 2 3:S,1 2,___,Wg:S,_,x,:Q}:
78 @echo ${:U12345:S,,sep,g:Q}
79
80 mod-C:
81 @echo $@:
82 @echo :${:Ua b b c:C,a b,,:Q}:
83 @echo :${:Ua b b c:C,a b,,1:Q}:
84 @echo :${:Ua b b c:C,a b,,W:Q}:
85 @echo :${:Uword1 word2:C,****,____,g:C,word,____,:Q}:
86 @echo :${:Ua b b c:C,b,,g:Q}:
87 @echo :${:U1 2 3 1 2 3:C,1 2,___,Wg:C,_,x,:Q}:
88
89 # In the :@ modifier, the name of the loop variable can even be generated
90 # dynamically. There's no practical use-case for this, and hopefully nobody
91 # will ever depend on this, but technically it's possible.
92 mod-at-varname:
93 @echo :${:Uone two three:@${:Ubar:S,b,v,}@+${var}+@:Q}:
94
95 # The :@ modifier resolves the variables a little more often than expected.
96 # In particular, it resolves _all_ variables from the context, and not only
97 # the loop variable (in this case v).
98 #
99 # The d means direct reference, the i means indirect reference.
100 RESOLVE= ${RES1} $${RES1}
101 RES1= 1d${RES2} 1i$${RES2}
102 RES2= 2d${RES3} 2i$${RES3}
103 RES3= 3
104
105 mod-at-resolve:
106 @echo $@:${RESOLVE:@v@w${v}w@:Q}:
107
108 # As of 2020-07-19, the variable name of the :@ modifier may end with one
109 # or two dollar signs, which are silently ignored. There's no point in
110 # allowing a dollar sign in that position.
111 mod-at-dollar:
112 @echo $@:${1 2 3:L:@v$@($v)@:Q}.
113 @echo $@:${1 2 3:L:@v$$@($v)@:Q}.
114 @echo $@:${1 2 3:L:@v$$$@($v)@:Q}.
115
116 # No matter how many dollar characters there are, they all get merged
117 # into a single dollar by the :S modifier.
118 mod-subst-dollar:
119 @echo $@:${:U1:S,^,$,:Q}:
120 @echo $@:${:U2:S,^,$$,:Q}:
121 @echo $@:${:U3:S,^,$$$,:Q}:
122 @echo $@:${:U4:S,^,$$$$,:Q}:
123 @echo $@:${:U5:S,^,$$$$$,:Q}:
124 @echo $@:${:U6:S,^,$$$$$$,:Q}:
125 @echo $@:${:U7:S,^,$$$$$$$,:Q}:
126 @echo $@:${:U8:S,^,$$$$$$$$,:Q}:
127 # This generates no dollar at all:
128 @echo $@:${:UU8:S,^,${:U$$$$$$$$},:Q}:
129 # Here is an alternative way to generate dollar characters.
130 # It's unexpectedly complicated though.
131 @echo $@:${:U:range=5:ts\x24:C,[0-9],,g:Q}:
132
133 # Demonstrate that it is possible to generate dollar characters using the
134 # :@ modifier.
135 #
136 # These are edge cases that could have resulted in a parse error as well
137 # since the $@ at the end could have been interpreted as a variable, which
138 # would mean a missing closing @ delimiter.
139 mod-loop-dollar:
140 @echo $@:${:U1:@word@${word}$@:Q}:
141 @echo $@:${:U2:@word@$${word}$$@:Q}:
142 @echo $@:${:U3:@word@$$${word}$$$@:Q}:
143 @echo $@:${:U4:@word@$$$${word}$$$$@:Q}:
144 @echo $@:${:U5:@word@$$$$${word}$$$$$@:Q}:
145 @echo $@:${:U6:@word@$$$$$${word}$$$$$$@:Q}:
146
147 mod-C-limits:
148 @echo $@:00-ok:${:U1 23 456:C,..,\0\0,:Q}
149 @echo $@:11-missing:${:U1 23 456:C,..,\1\1,:Q}
150 @echo $@:11-ok:${:U1 23 456:C,(.).,\1\1,:Q}
151 @echo $@:22-missing:${:U1 23 456:C,..,\2\2,:Q}
152 @echo $@:22-missing:${:U1 23 456:C,(.).,\2\2,:Q}
153 @echo $@:22-ok:${:U1 23 456:C,(.)(.),\2\2,:Q}
154 # The :C modifier only handles single-digit capturing groups,
155 # which is more than enough for daily use.
156 @echo $@:capture:${:UabcdefghijABCDEFGHIJrest:C,(.)(.)(.)(.)(.)(.)(.)(.)(.)(.)(.)(.)(.)(.)(.)(.)(.)(.)(.)(.),\9\8\7\6\5\4\3\2\1\0\10\11\12,}
157
158 mod-C-errors:
159 @echo $@: ${UNDEF:Uvalue:C,[,,}
160
161 # Just a bit of basic code coverage for the obscure ::= assignment modifiers.
162 mod-assign:
163 @echo $@: ${1 2 3:L:@i@${FIRST::?=$i}@} first=${FIRST}.
164 @echo $@: ${1 2 3:L:@i@${LAST::=$i}@} last=${LAST}.
165 @echo $@: ${1 2 3:L:@i@${APPENDED::+=$i}@} appended=${APPENDED}.
166 @echo $@: ${echo.1 echo.2 echo.3:L:@i@${RAN::!=${i:C,.*,&; & 1>\&2,:S,., ,g}}@} ran:${RAN}.
167 # The assignments happen in the global scope and thus are
168 # preserved even after the shell command has been run.
169 @echo $@: global: ${FIRST:Q}, ${LAST:Q}, ${APPENDED:Q}, ${RAN:Q}.
170
171 mod-assign-nested:
172 @echo $@: ${1:?${THEN1::=then1${IT1::=t1}}:${ELSE1::=else1${IE1::=e1}}}${THEN1}${ELSE1}${IT1}${IE1}
173 @echo $@: ${0:?${THEN2::=then2${IT2::=t2}}:${ELSE2::=else2${IE2::=e2}}}${THEN2}${ELSE2}${IT2}${IE2}
174 @echo $@: ${SINK3:Q}
175 @echo $@: ${SINK4:Q}
176 SINK3:= ${1:?${THEN3::=then3${IT3::=t3}}:${ELSE3::=else3${IE3::=e3}}}${THEN3}${ELSE3}${IT3}${IE3}
177 SINK4:= ${0:?${THEN4::=then4${IT4::=t4}}:${ELSE4::=else4${IE4::=e4}}}${THEN4}${ELSE4}${IT4}${IE4}
178
179 mod-tu-space:
180 # The :tu and :tl modifiers operate on the variable value
181 # as a single string, not as a list of words. Therefore,
182 # the adjacent spaces are preserved.
183 @echo $@: ${a b:L:tu:Q}
184
185 mod-Q:
186 @echo $@: new${.newline:Q}${.newline:Q}line
187
188 # Cover the bmake_realloc in brk_string.
189 mod-break-many-words:
190 @echo $@: ${UNDEF:U:range=500:[#]}
191