varmod-edge.mk revision 1.11
1 # $NetBSD: varmod-edge.mk,v 1.11 2020/08/01 15:28:28 rillig Exp $ 2 # 3 # Tests for edge cases in variable modifiers. 4 # 5 # These tests demonstrate the current implementation in small examples. 6 # They may contain surprising behavior. 7 # 8 # Each test consists of: 9 # - INP, the input to the test 10 # - MOD, the expression for testing the modifier 11 # - EXP, the expected output 12 13 TESTS+= M-paren 14 INP.M-paren= (parentheses) {braces} (opening closing) () 15 MOD.M-paren= ${INP.M-paren:M(*)} 16 EXP.M-paren= (parentheses) () 17 18 # The first closing brace matches the opening parenthesis. 19 # The second closing brace actually ends the variable expression. 20 # 21 # XXX: This is unexpected but rarely occurs in practice. 22 TESTS+= M-mixed 23 INP.M-mixed= (paren-brace} ( 24 MOD.M-mixed= ${INP.M-mixed:M(*}} 25 EXP.M-mixed= (paren-brace} 26 27 # After the :M modifier has parsed the pattern, only the closing brace 28 # and the colon are unescaped. The other characters are left as-is. 29 # To actually see this effect, the backslashes in the :M modifier need 30 # to be doubled since single backslashes would simply be unescaped by 31 # Str_Match. 32 # 33 # XXX: This is unexpected. The opening brace should also be unescaped. 34 TESTS+= M-unescape 35 INP.M-unescape= ({}): \(\{\}\)\: \(\{}\): 36 MOD.M-unescape= ${INP.M-unescape:M\\(\\{\\}\\)\\:} 37 EXP.M-unescape= \(\{}\): 38 39 # When the :M and :N modifiers are parsed, the pattern finishes as soon 40 # as open_parens + open_braces == closing_parens + closing_braces. This 41 # means that ( and } form a matching pair. 42 # 43 # Nested variable expressions are not parsed as such. Instead, only the 44 # parentheses and braces are counted. This leads to a parse error since 45 # the nested expression is not "${:U*)}" but only "${:U*)", which is 46 # missing the closing brace. The expression is evaluated anyway. 47 # The final brace in the output comes from the end of M.nest-mix. 48 # 49 # XXX: This is unexpected but rarely occurs in practice. 50 TESTS+= M-nest-mix 51 INP.M-nest-mix= (parentheses) 52 MOD.M-nest-mix= ${INP.M-nest-mix:M${:U*)}} 53 EXP.M-nest-mix= (parentheses)} 54 # make: Unclosed variable specification (expecting '}') for "" (value "*)") modifier U 55 56 # In contrast to parentheses and braces, the brackets are not counted 57 # when the :M modifier is parsed since Makefile variables only take the 58 # ${VAR} or $(VAR) forms, but not $[VAR]. 59 # 60 # The final ] in the pattern is needed to close the character class. 61 TESTS+= M-nest-brk 62 INP.M-nest-brk= [ [[ [[[ 63 MOD.M-nest-brk= ${INP.M-nest-brk:M${:U[[[[[]}} 64 EXP.M-nest-brk= [ 65 66 # The pattern in the nested variable has an unclosed character class. 67 # No error is reported though, and the pattern is closed implicitly. 68 # 69 # XXX: It is unexpected that no error is reported. 70 # See str.c, function Str_Match. 71 # 72 # Before 2019-12-02, this test case triggered an out-of-bounds read 73 # in Str_Match. 74 TESTS+= M-pat-err 75 INP.M-pat-err= [ [[ [[[ 76 MOD.M-pat-err= ${INP.M-pat-err:M${:U[[}} 77 EXP.M-pat-err= [ 78 79 # The first backslash does not escape the second backslash. 80 # Therefore, the second backslash escapes the parenthesis. 81 # This means that the pattern ends there. 82 # The final } in the output comes from the end of MOD.M-bsbs. 83 # 84 # If the first backslash were to escape the second backslash, the first 85 # closing brace would match the opening parenthesis (see M-mixed), and 86 # the second closing brace would be needed to close the variable. 87 # After that, the remaining backslash would escape the parenthesis in 88 # the pattern, therefore (} would match. 89 TESTS+= M-bsbs 90 INP.M-bsbs= (} \( \(} 91 MOD.M-bsbs= ${INP.M-bsbs:M\\(}} 92 EXP.M-bsbs= \(} 93 #EXP.M-bsbs= (} # If the first backslash were to escape ... 94 95 # The backslash in \( does not escape the parenthesis, therefore it 96 # counts for the nesting level and matches with the first closing brace. 97 # The second closing brace closes the variable, and the third is copied 98 # literally. 99 # 100 # The second :M in the pattern is nested between ( and }, therefore it 101 # does not start a new modifier. 102 TESTS+= M-bs1-par 103 INP.M-bs1-par= ( (:M (:M} \( \(:M \(:M} 104 MOD.M-bs1-par= ${INP.M-bs1-par:M\(:M*}}} 105 EXP.M-bs1-par= (:M}} 106 107 # The double backslash is passed verbatim to the pattern matcher. 108 # The Str_Match pattern is \\(:M*}, and there the backslash is unescaped. 109 # Again, the ( takes place in the nesting level, and there is no way to 110 # prevent this, no matter how many backslashes are used. 111 TESTS+= M-bs2-par 112 INP.M-bs2-par= ( (:M (:M} \( \(:M \(:M} 113 MOD.M-bs2-par= ${INP.M-bs2-par:M\\(:M*}}} 114 EXP.M-bs2-par= \(:M}} 115 116 # Str_Match uses a recursive algorithm for matching the * patterns. 117 # Make sure that it survives patterns with 128 asterisks. 118 # That should be enough for all practical purposes. 119 # To produce a stack overflow, just add more :Qs below. 120 TESTS+= M-128 121 INP.M-128= ${:U\\:Q:Q:Q:Q:Q:Q:Q:S,\\,x,g} 122 PAT.M-128= ${:U\\:Q:Q:Q:Q:Q:Q:Q:S,\\,*,g} 123 MOD.M-128= ${INP.M-128:M${PAT.M-128}} 124 EXP.M-128= ${INP.M-128} 125 126 # This is the normal SysV substitution. Nothing surprising here. 127 TESTS+= eq-ext 128 INP.eq-ext= file.c file.cc 129 MOD.eq-ext= ${INP.eq-ext:%.c=%.o} 130 EXP.eq-ext= file.o file.cc 131 132 # The SysV := modifier is greedy and consumes all the modifier text 133 # up until the closing brace or parenthesis. The :Q may look like a 134 # modifier, but it really isn't, that's why it appears in the output. 135 TESTS+= eq-q 136 INP.eq-q= file.c file.cc 137 MOD.eq-q= ${INP.eq-q:%.c=%.o:Q} 138 EXP.eq-q= file.o:Q file.cc 139 140 # The = in the := modifier can be escaped. 141 TESTS+= eq-bs 142 INP.eq-bs= file.c file.c=%.o 143 MOD.eq-bs= ${INP.eq-bs:%.c\=%.o=%.ext} 144 EXP.eq-bs= file.c file.ext 145 146 # Having only an escaped '=' results in a parse error. 147 # The call to "pattern.lhs = ParseModifierPart" fails. 148 TESTS+= eq-esc 149 INP.eq-esc= file.c file... 150 MOD.eq-esc= ${INP.eq-esc:a\=b} 151 EXP.eq-esc= # empty 152 # make: Unclosed substitution for INP.eq-esc (= missing) 153 154 TESTS+= colon 155 INP.colon= value 156 MOD.colon= ${INP.colon:} 157 EXP.colon= value 158 159 TESTS+= colons 160 INP.colons= value 161 MOD.colons= ${INP.colons::::} 162 EXP.colons= # empty 163 164 .for test in ${TESTS} 165 . if ${MOD.${test}} == ${EXP.${test}} 166 .info ok ${test} 167 . else 168 .warning error in ${test}: expected "${EXP.${test}}", got "${MOD.${test}}" 169 . endif 170 .endfor 171 172 all: 173 @echo ok 174
Indexes created Wed Oct 01 15:09:59 GMT 2025