1 # $NetBSD: varmod-match.mk,v 1.32 2025/06/29 09:40:13 rillig Exp $ 2 # 3 # Tests for the ':M' modifier, which keeps only those words that match the 4 # given pattern. 5 # 6 # Table of contents 7 # 8 # 1. Pattern characters '*', '?' and '\' 9 # 2. Character lists and character ranges 10 # 3. Parsing and escaping 11 # 4. Interaction with other modifiers 12 # 5. Performance 13 # 6. Error handling 14 # 7. Historical bugs 15 # 16 # See also: 17 # char-005c-reverse-solidus.mk 18 # ApplyModifier_Match 19 # ParseModifier_Match 20 # ModifyWord_Match 21 # Str_Match 22 23 24 # 1. Pattern characters '*', '?' and '\' 25 # 26 # * matches 0 or more characters 27 # ? matches 1 character 28 # \x matches the character 'x' 29 30 # The pattern is anchored both at the beginning and at the end of the word. 31 # Since the pattern 'e' does not contain any pattern matching characters, it 32 # matches exactly the word 'e', twice. 33 .if ${a c e aa cc ee e f g:L:Me} != "e e" 34 . error 35 .endif 36 37 # The pattern character '?' matches exactly 1 character, the pattern character 38 # '*' matches 0 or more characters. The whole pattern matches all words that 39 # start with 's' and have 3 or more characters. 40 .if ${One Two Three Four five six seven so s:L:Ms??*} != "six seven" 41 . error 42 .endif 43 44 # A pattern without placeholders only matches itself. 45 .if ${a aa aaa b ba baa bab:L:Ma} != "a" 46 . error 47 .endif 48 49 # A pattern that does not start with '*' is anchored at the beginning. 50 .if ${a aa aaa b ba baa bab:L:Ma*} != "a aa aaa" 51 . error 52 .endif 53 54 # A pattern that does not end with '*' is anchored at the end. 55 .if ${a aa aaa b ba baa bab:L:M*a} != "a aa aaa ba baa" 56 . error 57 .endif 58 59 # Test the fast code path for '*' followed by a regular character. 60 .if ${:U file.c file.*c file.h file\.c :M*.c} != "file.c file\\.c" 61 . error 62 .endif 63 # Ensure that the fast code path correctly handles the backslash. 64 .if ${:U file.c file.*c file.h file\.c :M*\.c} != "file.c file\\.c" 65 . error 66 .endif 67 # Ensure that the fast code path correctly handles '\*'. 68 .if ${:U file.c file.*c file.h file\.c :M*\*c} != "file.*c" 69 . error 70 .endif 71 # Ensure that the partial match '.c' doesn't confuse the fast code path. 72 .if ${:U file.c.cc file.cc.cc file.cc.c :M*.cc} != "file.c.cc file.cc.cc" 73 . error 74 .endif 75 # Ensure that the substring '.cc' doesn't confuse the fast code path for '.c'. 76 .if ${:U file.c.cc file.cc.cc file.cc.c :M*.c} != "file.cc.c" 77 . error 78 .endif 79 80 81 # 2. Character lists and character ranges 82 # 83 # [...] matches 1 character from the listed characters 84 # [^...] matches 1 character from the unlisted characters 85 # [a-z] matches 1 character from the range 'a' to 'z' 86 # [z-a] matches 1 character from the range 'a' to 'z' 87 88 # Only keep words that start with an uppercase letter. 89 .if ${One Two Three Four five six seven:L:M[A-Z]*} != "One Two Three Four" 90 . error 91 .endif 92 93 # Only keep words that start with a character other than an uppercase letter. 94 .if ${One Two Three Four five six seven:L:M[^A-Z]*} != "five six seven" 95 . error 96 .endif 97 98 # [] matches never 99 .if ${ ab a[]b a[b a b :L:M[]} != "" 100 . error 101 .endif 102 103 # a[]b matches never 104 .if ${ ab a[]b a[b a b [ ] :L:Ma[]b} != "" 105 . error 106 .endif 107 108 # [^] matches exactly 1 arbitrary character 109 .if ${ ab a[]b a[b a b [ ] :L:M[^]} != "a b [ ]" 110 . error 111 .endif 112 113 # a[^]b matches 'a', then exactly 1 arbitrary character, then 'b' 114 .if ${ ab a[]b a[b a b :L:Ma[^]b} != "a[b" 115 . error 116 .endif 117 118 # [Nn0] matches exactly 1 character from the set 'N', 'n', '0' 119 .if ${ a b N n 0 Nn0 [ ] :L:M[Nn0]} != "N n 0" 120 . error 121 .endif 122 123 # [a-c] matches exactly 1 character from the range 'a' to 'c' 124 .if ${ A B C a b c d [a-c] [a] :L:M[a-c]} != "a b c" 125 . error 126 .endif 127 128 # [c-a] matches the same as [a-c] 129 .if ${ A B C a b c d [a-c] [a] :L:M[c-a]} != "a b c" 130 . error 131 .endif 132 133 # [^a-c67] 134 # matches a single character, except for 'a', 'b', 'c', '6' or 135 # '7' 136 .if ${ A B C a b c d 5 6 7 8 [a-c] [a] :L:M[^a-c67]} != "A B C d 5 8" 137 . error 138 .endif 139 140 # [\] matches a single backslash; no escaping takes place in 141 # character ranges 142 # Without the 'b' in the below words, the backslash would end a word and thus 143 # influence how the string is split into words. 144 WORDS= a\b a[\]b ab a\\b 145 .if ${WORDS:Ma[\]b} != "a\\b" 146 . error 147 .endif 148 149 # [[-]] May look like it would match a single '[', '\' or ']', but 150 # the inner ']' has two roles: it is the upper bound of the 151 # character range as well as the closing character of the 152 # character list. The outer ']' is just a regular character. 153 WORDS= [ ] [] \] ]] 154 .if ${WORDS:M[[-]]} != "[] \\] ]]" 155 . error 156 .endif 157 158 # [b[-]a] 159 # Same as for '[[-]]': the character list stops at the first 160 # ']', and the 'a]' is treated as a literal string. 161 WORDS= [a \a ]a []a \]a ]]a [a] \a] ]a] ba] 162 .if ${WORDS:M[b[-]a]} != "[a] \\a] ]a] ba]" 163 . error 164 .endif 165 166 # [-] Matches a single '-' since the '-' only becomes part of a 167 # character range if it is preceded and followed by another 168 # character. 169 WORDS= - -] 170 .if ${WORDS:M[-]} != "-" 171 . error 172 .endif 173 174 # Only keep words that don't start with s and at the same time end with 175 # either of [ex]. 176 # 177 # This test case ensures that the negation from the first character list 178 # '[^s]' does not propagate to the second character list '[ex]'. 179 .if ${One Two Three Four five six seven:L:M[^s]*[ex]} != "One Three five" 180 . error 181 .endif 182 183 184 # 3. Parsing and escaping 185 # 186 # * matches 0 or more characters 187 # ? matches 1 character 188 # \ outside a character list, escapes the following character 189 # [ starts a character list for matching 1 character 190 # ] ends a character list for matching 1 character 191 # - in a character list, forms a character range 192 # ^ at the beginning of a character list, negates the list 193 # ( while parsing the pattern, starts a nesting level 194 # ) while parsing the pattern, ends a nesting level 195 # { while parsing the pattern, starts a nesting level 196 # } while parsing the pattern, ends a nesting level 197 # : while parsing the pattern, terminates the pattern 198 # $ while parsing the pattern, starts a nested expression 199 # # in a line except a shell command, starts a comment 200 201 # The pattern can come from an expression. For single-letter 202 # variables, either the short form or the long form can be used, just as 203 # everywhere else. 204 PRIMES= 2 3 5 7 11 205 n= 2 206 .if ${PRIMES:M$n} != "2" 207 . error 208 .endif 209 .if ${PRIMES:M${n}} != "2" 210 . error 211 .endif 212 .if ${PRIMES:M${:U2}} != "2" 213 . error 214 .endif 215 216 # : terminates the pattern 217 .if ${ A * :L:M:} != "" 218 . error 219 .endif 220 221 # \: matches a colon 222 .if ${ ${:U\: \:\:} :L:M\:} != ":" 223 . error 224 .endif 225 226 # ${:U\:} matches a colon 227 .if ${ ${:U\:} ${:U\:\:} :L:M${:U\:}} != ":" 228 . error 229 .endif 230 231 # To match a dollar sign in a word, double it. 232 # 233 # This is different from the :S and :C modifiers, where a '$' has to be 234 # escaped as '\$'. 235 .if ${:Ua \$ sign:M*$$*} != "\$" 236 . error 237 .endif 238 239 # In the :M modifier, '\$' does not escape a dollar. Instead it is 240 # interpreted as a backslash followed by whatever expression the 241 # '$' starts. 242 # 243 # This differs from the :S, :C and several other modifiers. 244 ${:U*}= asterisk 245 .if ${:Ua \$ sign any-asterisk:M*\$*} != "any-asterisk" 246 . error 247 .endif 248 249 # TODO: ${VAR:M(((}}}} 250 # TODO: ${VAR:M{{{)))} 251 # TODO: ${VAR:M${UNBALANCED}} 252 # TODO: ${VAR:M${:U(((\}\}\}}} 253 254 255 # 4. Interaction with other modifiers 256 257 # The modifier ':tW' prevents splitting at whitespace. Even leading and 258 # trailing whitespace is preserved. 259 .if ${ plain string :L:tW:M*} != " plain string " 260 . error 261 .endif 262 263 # Without the modifier ':tW', the string is split into words. Whitespace 264 # around the words is discarded, and whitespace between the words is 265 # normalized to a single space. 266 .if ${ plain string :L:M*} != "plain string" 267 . error 268 .endif 269 270 271 # 5. Performance 272 273 # Before 2020-06-13, this expression called Str_Match 601,080,390 times. 274 # Since 2020-06-13, this expression calls Str_Match 1 time. 275 .if ${:U****************:M****************b} 276 .endif 277 278 # Before 2023-06-22, this expression called Str_Match 2,621,112 times. 279 # Adding another '*?' to the pattern called Str_Match 20,630,572 times. 280 # Adding another '*?' to the pattern called Str_Match 136,405,672 times. 281 # Adding another '*?' to the pattern called Str_Match 773,168,722 times. 282 # Adding another '*?' to the pattern called Str_Match 3,815,481,072 times. 283 # Since 2023-06-22, Str_Match no longer backtracks. 284 .if ${:U..................................................b:M*?*?*?*?*?a} 285 .endif 286 287 288 # 6. Error handling 289 290 # [ Incomplete empty character list, never matches. 291 WORDS= a a[ 292 # expect+1: Unfinished character list in pattern "a[" of modifier ":M" 293 .if ${WORDS:Ma[} != "" 294 . error 295 .endif 296 297 # [^ Incomplete negated empty character list, matches any single 298 # character. 299 WORDS= a a[ aX 300 # expect+1: Unfinished character list in pattern "a[^" of modifier ":M" 301 .if ${WORDS:Ma[^} != "a[ aX" 302 . error 303 .endif 304 305 # [-x1-3 Incomplete character list, matches those elements that can be 306 # parsed without lookahead. 307 WORDS= - + x xx 0 1 2 3 4 [x1-3 308 # expect+1: Unfinished character list in pattern "[-x1-3" of modifier ":M" 309 .if ${WORDS:M[-x1-3} != "- x 1 2 3" 310 . error 311 .endif 312 313 # *[-x1-3 Incomplete character list after a wildcard, matches those 314 # words that end with one of the characters from the list. 315 WORDS= - + x xx 0 1 2 3 4 00 01 10 11 000 001 010 011 100 101 110 111 [x1-3 316 # expect+1: Unfinished character list in pattern "*[-x1-3" of modifier ":M" 317 .if ${WORDS:M*[-x1-3} != "- x xx 1 2 3 01 11 001 011 101 111 [x1-3" 318 . warning ${WORDS:M*[-x1-3} 319 .endif 320 321 # [^-x1-3 322 # Incomplete negated character list, matches any character 323 # except those elements that can be parsed without lookahead. 324 WORDS= - + x xx 0 1 2 3 4 [x1-3 325 # expect+1: Unfinished character list in pattern "[^-x1-3" of modifier ":M" 326 .if ${WORDS:M[^-x1-3} != "+ 0 4" 327 . error 328 .endif 329 330 # [\ Incomplete character list containing a single '\'. 331 # 332 # A word can only end with a backslash if the preceding 333 # character is a backslash as well; in all other cases the final 334 # backslash would escape the following space, making the space 335 # part of the word. Only the very last word of a string can be 336 # '\', as there is no following space that could be escaped. 337 WORDS= \\ \a ${:Ux\\} 338 PATTERN= ${:U?[\\} 339 # expect+1: Unfinished character list in pattern "?[\" of modifier ":M" 340 .if ${WORDS:M${PATTERN}} != "\\\\ x\\" 341 . error 342 .endif 343 344 # [x- Incomplete character list containing an incomplete character 345 # range, matches only the 'x'. 346 WORDS= [x- x x- y 347 # expect+1: Unfinished character range in pattern "[x-" of modifier ":M" 348 .if ${WORDS:M[x-} != "x" 349 . error 350 .endif 351 352 # [^x- Incomplete negated character list containing an incomplete 353 # character range; matches each word that does not have an 'x' 354 # at the position of the character list. 355 # 356 # XXX: Even matches strings that are longer than a single 357 # character. 358 WORDS= [x- x x- y yyyyy 359 # expect+1: Unfinished character range in pattern "[^x-" of modifier ":M" 360 .if ${WORDS:M[^x-} != "[x- y yyyyy" 361 . error 362 .endif 363 364 # [:] matches never since the ':' starts the next modifier 365 # expect+2: Unfinished character list in pattern "[" of modifier ":M" 366 # expect+1: Unknown modifier ":]" 367 .if ${ ${:U\:} ${:U\:\:} :L:M[:]} != ":" 368 . error 369 .else 370 . error 371 .endif 372 373 374 # 7. Historical bugs 375 376 # Before var.c 1.1031 from 2022-08-24, the following expressions caused an 377 # out-of-bounds read beyond the indirect ':M' modifiers. 378 # 379 # The argument to the inner ':U' is unescaped to 'M\'. 380 # This 'M\' becomes an indirect modifier ':M' with the pattern '\'. 381 # The pattern '\' never matches. 382 .if ${:U:${:UM\\}} 383 . error 384 .endif 385 # The argument to the inner ':U' is unescaped to 'M\:\'. 386 # This 'M\:\' becomes an indirect modifier ':M' with the pattern ':\'. 387 # The pattern ':\' never matches. 388 .if ${:U:${:UM\\\:\\}} 389 . error 390 .endif 391
Indexes created Mon Sep 29 21:09:56 GMT 2025