varmod-edge.mk revision 1.5
1 # $NetBSD: varmod-edge.mk,v 1.5 2019/12/01 23:53:49 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 55 # In contrast to parentheses and braces, the brackets are not counted 56 # when the :M modifier is parsed since Makefile variables only take the 57 # ${VAR} or $(VAR) forms, but not $[VAR]. 58 # 59 # The final ] in the pattern is needed to close the character class. 60 TESTS+= M-nest-brk 61 INP.M-nest-brk= [ [[ [[[ 62 MOD.M-nest-brk= ${INP.M-nest-brk:M${:U[[[[[]}} 63 EXP.M-nest-brk= [ 64 65 # The pattern in the nested variable has an unclosed character class. 66 # No error is reported though, and the pattern is closed implicitly. 67 # 68 # XXX: It is unexpected that no error is reported. 69 # See str.c, function Str_Match. 70 # 71 # Before 2019-12-02, this test case triggered an out-of-bounds read 72 # in Str_Match. 73 TESTS+= M-pat-err 74 INP.M-pat-err= [ [[ [[[ 75 MOD.M-pat-err= ${INP.M-pat-err:M${:U[[}} 76 EXP.M-pat-err= [ 77 78 # The first backslash does not escape the second backslash. 79 # Therefore, the second backslash escapes the parenthesis. 80 # This means that the pattern ends there. 81 # The final } in the output comes from the end of MOD.M-bsbs. 82 # 83 # If the first backslash were to escape the second backslash, the first 84 # closing brace would match the opening parenthesis (see M-mixed), and 85 # the second closing brace would be needed to close the variable. 86 # After that, the remaining backslash would escape the parenthesis in 87 # the pattern, therefore (} would match. 88 TESTS+= M-bsbs 89 INP.M-bsbs= (} \( \(} 90 MOD.M-bsbs= ${INP.M-bsbs:M\\(}} 91 EXP.M-bsbs= \(} 92 #EXP.M-bsbs= (} # If the first backslash were to escape ... 93 94 # The backslash in \( does not escape the parenthesis, therefore it 95 # counts for the nesting level and matches with the first closing brace. 96 # The second closing brace closes the variable, and the third is copied 97 # literally. 98 # 99 # The second :M in the pattern is nested between ( and }, therefore it 100 # does not start a new modifier. 101 TESTS+= M-bs1-par 102 INP.M-bs1-par= ( (:M (:M} \( \(:M \(:M} 103 MOD.M-bs1-par= ${INP.M-bs1-par:M\(:M*}}} 104 EXP.M-bs1-par= (:M}} 105 106 # The double backslash is passed verbatim to the pattern matcher. 107 # The Str_Match pattern is \\(:M*}, and there the backslash is unescaped. 108 # Again, the ( takes place in the nesting level, and there is no way to 109 # prevent this, no matter how many backslashes are used. 110 TESTS+= M-bs2-par 111 INP.M-bs2-par= ( (:M (:M} \( \(:M \(:M} 112 MOD.M-bs2-par= ${INP.M-bs2-par:M\\(:M*}}} 113 EXP.M-bs2-par= \(:M}} 114 115 all: 116 .for test in ${TESTS} 117 . if ${MOD.${test}} == ${EXP.${test}} 118 @printf 'ok %s\n' ${test:Q}'' 119 . else 120 @printf 'error in %s: expected %s, got %s\n' \ 121 ${test:Q}'' ${EXP.${test}:Q}'' ${MOD.${test}:Q}'' 122 . endif 123 .endfor 124
Indexes created Wed Oct 01 07:09:59 GMT 2025