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. 144WORDS= 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. 153WORDS= [ ] [] \] ]] 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. 161WORDS= [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. 169WORDS= - -] 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. 204PRIMES= 2 3 5 7 11 205n= 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. 291WORDS= 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. 299WORDS= 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. 307WORDS= - + 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. 315WORDS= - + 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. 324WORDS= - + 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. 337WORDS= \\ \a ${:Ux\\} 338PATTERN= ${: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'. 346WORDS= [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. 358WORDS= [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