var-eval-short.mk revision 1.7
1 # $NetBSD: var-eval-short.mk,v 1.7 2021/09/07 20:41:58 rillig Exp $ 2 # 3 # Tests for each variable modifier to ensure that they only do the minimum 4 # necessary computations. If the result of the expression is not needed, they 5 # should only parse the modifier but not actually evaluate it. 6 # 7 # See also: 8 # var.c, the comment starting with 'The ApplyModifier functions' 9 # ApplyModifier, for the order of the modifiers 10 # ParseModifierPart, for evaluating nested expressions 11 # cond-short.mk 12 13 FAIL= ${:!echo unexpected 1>&2!} 14 15 # The following tests only ensure that nested expressions are not evaluated. 16 # They cannot ensure that any unexpanded text returned from ParseModifierPart 17 # is ignored as well. To do that, it is necessary to step through the code of 18 # each modifier. 19 20 .if 0 && ${FAIL} 21 .endif 22 23 .if 0 && ${VAR::=${FAIL}} 24 .elif defined(VAR) 25 . error 26 .endif 27 28 .if 0 && ${${FAIL}:?then:else} 29 .endif 30 31 .if 0 && ${1:?${FAIL}:${FAIL}} 32 .endif 33 34 .if 0 && ${0:?${FAIL}:${FAIL}} 35 .endif 36 37 # Before var.c 1.870 from 2021-03-14, the expression ${FAIL} was evaluated 38 # after the loop, when undefining the temporary global loop variable. 39 # Since var.c 1.907 from 2021-04-04, a '$' is no longer allowed in the 40 # variable name. 41 .if 0 && ${:Uword:@${FAIL}@expr@} 42 .endif 43 44 .if 0 && ${:Uword:@var@${FAIL}@} 45 .endif 46 47 # Before var.c 1.877 from 2021-03-14, the modifier ':[...]' did not expand 48 # the nested expression ${FAIL} and then tried to parse the unexpanded text, 49 # which failed since '$' is not a valid range character. 50 .if 0 && ${:Uword:[${FAIL}]} 51 .endif 52 53 # Before var.c 1.867 from 2021-03-14, the modifier ':_' defined the variable 54 # even though the whole expression should have only been parsed, not 55 # evaluated. 56 .if 0 && ${:Uword:_=VAR} 57 .elif defined(VAR) 58 . error 59 .endif 60 61 # Before var.c 1.856 from 2021-03-14, the modifier ':C' did not expand the 62 # nested expression ${FAIL}, which is correct, and then tried to compile the 63 # unexpanded text as a regular expression, which is unnecessary since the 64 # right-hand side of the '&&' cannot influence the outcome of the condition. 65 # Compiling the regular expression then failed both because of the '{FAIL}', 66 # which is not a valid repetition of the form '{1,5}', and because of the 67 # '****', which are repeated repetitions as well. 68 # '${FAIL}' 69 .if 0 && ${:Uword:C,${FAIL}****,,} 70 .endif 71 72 DEFINED= # defined 73 .if 0 && ${DEFINED:D${FAIL}} 74 .endif 75 76 .if 0 && ${:Uword:E} 77 .endif 78 79 # As of 2021-03-14, the error 'Invalid time value: ${FAIL}}' is ok since 80 # ':gmtime' does not expand its argument. 81 .if 0 && ${:Uword:gmtime=${FAIL}} 82 .endif 83 84 .if 0 && ${:Uword:H} 85 .endif 86 87 .if 0 && ${:Uword:hash} 88 .endif 89 90 .if 0 && ${value:L} 91 .endif 92 93 # As of 2021-03-14, the error 'Invalid time value: ${FAIL}}' is ok since 94 # ':localtime' does not expand its argument. 95 .if 0 && ${:Uword:localtime=${FAIL}} 96 .endif 97 98 .if 0 && ${:Uword:M${FAIL}} 99 .endif 100 101 .if 0 && ${:Uword:N${FAIL}} 102 .endif 103 104 .if 0 && ${:Uword:O} 105 .endif 106 107 .if 0 && ${:Uword:Ox} 108 .endif 109 110 .if 0 && ${:Uword:P} 111 .endif 112 113 .if 0 && ${:Uword:Q} 114 .endif 115 116 .if 0 && ${:Uword:q} 117 .endif 118 119 .if 0 && ${:Uword:R} 120 .endif 121 122 .if 0 && ${:Uword:range} 123 .endif 124 125 .if 0 && ${:Uword:S,${FAIL},${FAIL},} 126 .endif 127 128 .if 0 && ${:Uword:sh} 129 .endif 130 131 .if 0 && ${:Uword:T} 132 .endif 133 134 .if 0 && ${:Uword:ts/} 135 .endif 136 137 .if 0 && ${:U${FAIL}} 138 .endif 139 140 .if 0 && ${:Uword:u} 141 .endif 142 143 .if 0 && ${:Uword:word=replacement} 144 .endif 145 146 # Before var.c 1.875 from 2021-03-14, Var_Parse returned "${FAIL}else" for the 147 # irrelevant right-hand side of the condition, even though this was not 148 # necessary. Since the return value from Var_Parse is supposed to be ignored 149 # anyway, and since it is actually ignored in an overly complicated way, 150 # an empty string suffices. 151 .MAKEFLAGS: -dcpv 152 .if 0 && ${0:?${FAIL}then:${FAIL}else} 153 .endif 154 155 # The ':L' is applied before the ':?' modifier, giving the expression a name 156 # and a value, just to see whether this value gets passed through or whether 157 # the parse-only mode results in an empty string (only visible in the debug 158 # log). As of var.c 1.875 from 2021-03-14, the value of the variable gets 159 # through, even though an empty string would suffice. 160 DEFINED= defined 161 .if 0 && ${DEFINED:L:?${FAIL}then:${FAIL}else} 162 .endif 163 .MAKEFLAGS: -d0 164 165 all: 166
Indexes created Tue Oct 21 16:10:11 GMT 2025