1# $NetBSD: varmod-edge.mk,v 1.16 2021/02/23 15:56:30 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 13TESTS+= M-paren 14INP.M-paren= (parentheses) {braces} (opening closing) () 15MOD.M-paren= ${INP.M-paren:M(*)} 16EXP.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. 22TESTS+= M-mixed 23INP.M-mixed= (paren-brace} ( 24MOD.M-mixed= ${INP.M-mixed:M(*}} 25EXP.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. 34TESTS+= M-unescape 35INP.M-unescape= ({}): \(\{\}\)\: \(\{}\): 36MOD.M-unescape= ${INP.M-unescape:M\\(\\{\\}\\)\\:} 37EXP.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. 50TESTS+= M-nest-mix 51INP.M-nest-mix= (parentheses) 52MOD.M-nest-mix= ${INP.M-nest-mix:M${:U*)}} 53EXP.M-nest-mix= (parentheses)} 54# make: Unclosed variable expression, expecting '}' for modifier "U*)" of variable "" with value "*)" 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. 61TESTS+= M-nest-brk 62INP.M-nest-brk= [ [[ [[[ 63MOD.M-nest-brk= ${INP.M-nest-brk:M${:U[[[[[]}} 64EXP.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. 74TESTS+= M-pat-err 75INP.M-pat-err= [ [[ [[[ 76MOD.M-pat-err= ${INP.M-pat-err:M${:U[[}} 77EXP.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. 89TESTS+= M-bsbs 90INP.M-bsbs= (} \( \(} 91MOD.M-bsbs= ${INP.M-bsbs:M\\(}} 92EXP.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. 102TESTS+= M-bs1-par 103INP.M-bs1-par= ( (:M (:M} \( \(:M \(:M} 104MOD.M-bs1-par= ${INP.M-bs1-par:M\(:M*}}} 105EXP.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. 111TESTS+= M-bs2-par 112INP.M-bs2-par= ( (:M (:M} \( \(:M \(:M} 113MOD.M-bs2-par= ${INP.M-bs2-par:M\\(:M*}}} 114EXP.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. 120TESTS+= M-128 121INP.M-128= ${:U\\:Q:Q:Q:Q:Q:Q:Q:S,\\,x,g} 122PAT.M-128= ${:U\\:Q:Q:Q:Q:Q:Q:Q:S,\\,*,g} 123MOD.M-128= ${INP.M-128:M${PAT.M-128}} 124EXP.M-128= ${INP.M-128} 125 126# This is the normal SysV substitution. Nothing surprising here. 127TESTS+= eq-ext 128INP.eq-ext= file.c file.cc 129MOD.eq-ext= ${INP.eq-ext:%.c=%.o} 130EXP.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. 135TESTS+= eq-q 136INP.eq-q= file.c file.cc 137MOD.eq-q= ${INP.eq-q:%.c=%.o:Q} 138EXP.eq-q= file.o:Q file.cc 139 140# The = in the := modifier can be escaped. 141TESTS+= eq-bs 142INP.eq-bs= file.c file.c=%.o 143MOD.eq-bs= ${INP.eq-bs:%.c\=%.o=%.ext} 144EXP.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. 148TESTS+= eq-esc 149INP.eq-esc= file.c file... 150MOD.eq-esc= ${INP.eq-esc:a\=b} 151EXP.eq-esc= # empty 152# make: Unfinished modifier for INP.eq-esc ('=' missing) 153 154TESTS+= colon 155INP.colon= value 156MOD.colon= ${INP.colon:} 157EXP.colon= value 158 159TESTS+= colons 160INP.colons= value 161MOD.colons= ${INP.colons::::} 162EXP.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# Even in expressions based on an unnamed variable, there may be errors. 173# XXX: The error message should mention the variable name of the expression, 174# even though that name is empty in this case. 175.if ${:Z} 176. error 177.else 178. error 179.endif 180 181# Even in expressions based on an unnamed variable, there may be errors. 182# 183# Before var.c 1.842 from 2021-02-23, the error message did not surround the 184# variable name with quotes, leading to the rather confusing "Unfinished 185# modifier for (',' missing)", having two spaces in a row. 186# 187# XXX: The error message should report the filename:lineno. 188.if ${:S,} 189. error 190.else 191. error 192.endif 193 194all: 195 @echo ok 196