varmod-edge.mk revision 1.35
1 # $NetBSD: varmod-edge.mk,v 1.35 2025/03/29 16:44:14 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 INP= (parentheses) {braces} (opening closing) () 14 MOD= ${INP:M(*)} 15 EXP= (parentheses) () 16 .if ${MOD} != ${EXP} 17 . warning expected "${EXP}", got "${MOD}" 18 .endif 19 20 # The first closing brace matches the opening parenthesis. 21 # The second closing brace actually ends the expression. 22 # 23 # XXX: This is unexpected but rarely occurs in practice. 24 INP= (paren-brace} ( 25 MOD= ${INP:M(*}} 26 EXP= (paren-brace} 27 .if ${MOD} != ${EXP} 28 . warning expected "${EXP}", got "${MOD}" 29 .endif 30 31 # After the :M modifier has parsed the pattern, only the closing brace 32 # and the colon are unescaped. The other characters are left as-is. 33 # To actually see this effect, the backslashes in the :M modifier need 34 # to be doubled since single backslashes would simply be unescaped by 35 # Str_Match. 36 # 37 # XXX: This is unexpected. The opening brace should also be unescaped. 38 INP= ({}): \(\{\}\)\: \(\{}\): 39 MOD= ${INP:M\\(\\{\\}\\)\\:} 40 EXP= \(\{}\): 41 .if ${MOD} != ${EXP} 42 . warning expected "${EXP}", got "${MOD}" 43 .endif 44 45 # When the :M and :N modifiers are parsed, the pattern finishes as soon 46 # as open_parens + open_braces == closing_parens + closing_braces. This 47 # means that ( and } form a matching pair. 48 # 49 # Nested expressions are not parsed as such. Instead, only the 50 # parentheses and braces are counted. This leads to a parse error since 51 # the nested expression is not "${:U*)}" but only "${:U*)", which is 52 # missing the closing brace. The expression is evaluated anyway. 53 # The final brace in the output comes from the end of M.nest-mix. 54 # 55 # XXX: This is unexpected but rarely occurs in practice. 56 INP= (parentheses) 57 MOD= ${INP:M${:U*)}} 58 EXP= (parentheses)} 59 # expect+1: Unclosed expression, expecting '}' for modifier "U*)" 60 .if ${MOD} != ${EXP} 61 . warning expected "${EXP}", got "${MOD}" 62 .endif 63 64 65 # In contrast to parentheses and braces, the brackets are not counted 66 # when the :M modifier is parsed since Makefile expressions only take the 67 # ${VAR} or $(VAR) forms, but not $[VAR]. 68 # 69 # The final ] in the pattern is needed to close the character class. 70 INP= [ [[ [[[ 71 MOD= ${INP:M${:U[[[[[]}} 72 EXP= [ 73 .if ${MOD} != ${EXP} 74 . warning expected "${EXP}", got "${MOD}" 75 .endif 76 77 78 # The pattern in the nested variable has an unclosed character class. 79 # 80 # Before str.c 1.104 from 2024-07-06, no error was reported. 81 # 82 # Before 2019-12-02, this test case triggered an out-of-bounds read 83 # in Str_Match. 84 INP= [ [[ [[[ 85 MOD= ${INP:M${:U[[}} 86 EXP= [ 87 # expect+1: Unfinished character list in pattern '[[' of modifier ':M' 88 .if ${MOD} != ${EXP} 89 . warning expected "${EXP}", got "${MOD}" 90 .endif 91 92 # The first backslash does not escape the second backslash. 93 # Therefore, the second backslash escapes the parenthesis. 94 # This means that the pattern ends there. 95 # The final } in the output comes from the end of MOD. 96 # 97 # If the first backslash were to escape the second backslash, the first 98 # closing brace would match the opening parenthesis (see paren-brace), and 99 # the second closing brace would be needed to close the variable. 100 # After that, the remaining backslash would escape the parenthesis in 101 # the pattern, therefore (} would match. 102 INP= (} \( \(} 103 MOD= ${INP:M\\(}} 104 EXP= \(} 105 #EXP= (} # If the first backslash were to escape ... 106 .if ${MOD} != ${EXP} 107 . warning expected "${EXP}", got "${MOD}" 108 .endif 109 110 # The backslash in \( does not escape the parenthesis, therefore it 111 # counts for the nesting level and matches with the first closing brace. 112 # The second closing brace closes the variable, and the third is copied 113 # literally. 114 # 115 # The second :M in the pattern is nested between ( and }, therefore it 116 # does not start a new modifier. 117 INP= ( (:M (:M} \( \(:M \(:M} 118 MOD= ${INP:M\(:M*}}} 119 EXP= (:M}} 120 .if ${MOD} != ${EXP} 121 . warning expected "${EXP}", got "${MOD}" 122 .endif 123 124 # The double backslash is passed verbatim to the pattern matcher. 125 # The Str_Match pattern is \\(:M*}, and there the backslash is unescaped. 126 # Again, the ( takes place in the nesting level, and there is no way to 127 # prevent this, no matter how many backslashes are used. 128 INP= ( (:M (:M} \( \(:M \(:M} 129 MOD= ${INP:M\\(:M*}}} 130 EXP= \(:M}} 131 .if ${MOD} != ${EXP} 132 . warning expected "${EXP}", got "${MOD}" 133 .endif 134 135 # Before str.c 1.48 from 2020-06-15, Str_Match used a recursive algorithm for 136 # matching the '*' patterns and did not optimize for multiple '*' in a row. 137 # Test a pattern with 65536 asterisks. 138 INP= ${:U\\:Q:Q:Q:Q:Q:Q:Q:Q:Q:Q:Q:Q:Q:Q:Q:Q:S,\\,x,g} 139 PAT= ${:U\\:Q:Q:Q:Q:Q:Q:Q:Q:Q:Q:Q:Q:Q:Q:Q:Q:S,\\,*,g} 140 MOD= ${INP:M${PAT}} 141 EXP= ${INP} 142 .if ${MOD} != ${EXP} 143 . warning expected "${EXP}", got "${MOD}" 144 .endif 145 146 # This is the normal SysV substitution. Nothing surprising here. 147 INP= file.c file.cc 148 MOD= ${INP:%.c=%.o} 149 EXP= file.o file.cc 150 .if ${MOD} != ${EXP} 151 . warning expected "${EXP}", got "${MOD}" 152 .endif 153 154 # The SysV := modifier is greedy and consumes all the modifier text 155 # up until the closing brace or parenthesis. The :Q may look like a 156 # modifier, but it really isn't, that's why it appears in the output. 157 INP= file.c file.cc 158 MOD= ${INP:%.c=%.o:Q} 159 EXP= file.o:Q file.cc 160 .if ${MOD} != ${EXP} 161 . warning expected "${EXP}", got "${MOD}" 162 .endif 163 164 # The = in the := modifier can be escaped. 165 INP= file.c file.c=%.o 166 MOD= ${INP:%.c\=%.o=%.ext} 167 EXP= file.c file.ext 168 .if ${MOD} != ${EXP} 169 . warning expected "${EXP}", got "${MOD}" 170 .endif 171 172 # Having only an escaped '=' results in a parse error. 173 # The call to "pattern.lhs = ParseModifierPart" fails. 174 INP= file.c file... 175 MOD= ${INP:a\=b} 176 EXP= # empty 177 # expect+1: Unfinished modifier after "a\=b}", expecting "=" 178 .if ${MOD} != ${EXP} 179 . warning expected "${EXP}", got "${MOD}" 180 .endif 181 182 INP= value 183 MOD= ${INP:} 184 EXP= value 185 .if ${MOD} != ${EXP} 186 . warning expected "${EXP}", got "${MOD}" 187 .endif 188 189 INP= value 190 MOD= ${INP::::} 191 EXP= :} 192 # expect+1: Unknown modifier ":" 193 .if ${MOD} != ${EXP} 194 . warning expected "${EXP}", got "${MOD}" 195 .endif 196 197 # Even in expressions based on an unnamed variable, there may be errors. 198 # expect+1: Unknown modifier "Z" 199 .if ${:Z} 200 . error 201 .else 202 . error 203 .endif 204 205 # Even in expressions based on an unnamed variable, there may be errors. 206 # 207 # Before var.c 1.842 from 2021-02-23, the error message did not surround the 208 # variable name with quotes, leading to the rather confusing "Unfinished 209 # modifier for (',' missing)", having two spaces in a row. 210 # 211 # expect+1: Unfinished modifier after "}", expecting "," 212 .if ${:S,} 213 . error 214 .else 215 . error 216 .endif 217
Indexes created Wed Oct 01 15:09:59 GMT 2025