var-eval-short.mk revision 1.17
1 # $NetBSD: var-eval-short.mk,v 1.17 2025/01/11 20:54:45 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 irrelevant, 5 # the modifier should only be parsed. The modifier should not be evaluated, 6 # but if it is evaluated for simplicity of the code (such as ':ts'), it must 7 # not have any observable side effects. 8 # 9 # See also: 10 # var.c, the comment starting with 'The ApplyModifier functions' 11 # ParseModifierPart, for evaluating nested expressions 12 # cond-short.mk 13 14 FAIL= ${:!echo unexpected 1>&2!} 15 16 # The following tests only ensure that nested expressions are not evaluated. 17 # They cannot ensure that any unexpanded text returned from ParseModifierPart 18 # is ignored as well. To do that, it is necessary to step through the code of 19 # each modifier. 20 21 # TODO: Test the modifiers in the same order as they occur in ApplyModifier. 22 23 .if 0 && ${FAIL} 24 .endif 25 26 .if 0 && ${VAR::=${FAIL}} 27 .elif defined(VAR) 28 . error 29 .endif 30 31 .if 0 && ${${FAIL}:?then:else} 32 .endif 33 34 .if 0 && ${1:?${FAIL}:${FAIL}} 35 .endif 36 37 .if 0 && ${0:?${FAIL}:${FAIL}} 38 .endif 39 40 # Before var.c 1.870 from 2021-03-14, the expression ${FAIL} was evaluated 41 # after the loop, when undefining the temporary global loop variable. 42 # Since var.c 1.907 from 2021-04-04, a '$' is no longer allowed in the 43 # variable name. 44 # expect+1: In the :@ modifier, the variable name "${FAIL}" must not contain a dollar 45 .if 0 && ${:Uword:@${FAIL}@expr@} 46 .endif 47 48 .if 0 && ${:Uword:@var@${FAIL}@} 49 .endif 50 51 # Before var.c 1.877 from 2021-03-14, the modifier ':[...]' did not expand 52 # the nested expression ${FAIL} and then tried to parse the unexpanded text, 53 # which failed since '$' is not a valid range character. 54 .if 0 && ${:Uword:[${FAIL}]} 55 .endif 56 57 # Before var.c 1.867 from 2021-03-14, the modifier ':_' defined the variable 58 # even though the whole expression should have only been parsed, not 59 # evaluated. 60 .if 0 && ${:Uword:_=VAR} 61 .elif defined(VAR) 62 . error 63 .endif 64 65 # Before var.c 1.856 from 2021-03-14, the modifier ':C' did not expand the 66 # nested expression ${FAIL}, which is correct, and then tried to compile the 67 # unexpanded text as a regular expression, which is unnecessary since the 68 # right-hand side of the '&&' cannot influence the outcome of the condition. 69 # Compiling the regular expression then failed both because of the '{FAIL}', 70 # which is not a valid repetition of the form '{1,5}', and because of the 71 # '****', which are repeated repetitions as well. 72 # '${FAIL}' 73 .if 0 && ${:Uword:C,${FAIL}****,,} 74 .endif 75 76 DEFINED= # defined 77 .if 0 && ${DEFINED:D${FAIL}} 78 .endif 79 80 .if 0 && ${:Uword:E} 81 .endif 82 83 # Before var.c 1.1050 from 2023-05-09, the ':gmtime' modifier produced the 84 # error message 'Invalid time value: ${FAIL}}' since it did not expand its 85 # argument. 86 .if 0 && ${:Uword:gmtime=${FAIL}} 87 .endif 88 89 .if 0 && ${:Uword:H} 90 .endif 91 92 .if 0 && ${:Uword:hash} 93 .endif 94 95 .if 0 && ${value:L} 96 .endif 97 98 # Before var.c 1.1050 from 2023-05-09, the ':localtime' modifier produced the 99 # error message 'Invalid time value: ${FAIL}}' since it did not expand its 100 # argument. 101 .if 0 && ${:Uword:localtime=${FAIL}} 102 .endif 103 104 .if 0 && ${:Uword:M${FAIL}} 105 .endif 106 107 .if 0 && ${:Uword:N${FAIL}} 108 .endif 109 110 .if 0 && ${:Uword:O} 111 .endif 112 113 .if 0 && ${:Uword:Ox} 114 .endif 115 116 .if 0 && ${:Uword:P} 117 .endif 118 119 .if 0 && ${:Uword:Q} 120 .endif 121 122 .if 0 && ${:Uword:q} 123 .endif 124 125 .if 0 && ${:Uword:R} 126 .endif 127 128 .if 0 && ${:Uword:range} 129 .endif 130 131 .if 0 && ${:Uword:S,${FAIL},${FAIL},} 132 .endif 133 134 .if 0 && ${:Uword:sh} 135 .endif 136 137 .if 0 && ${:Uword:T} 138 .endif 139 140 .if 0 && ${:Uword:ts/} 141 .endif 142 143 .if 0 && ${:U${FAIL}} 144 .endif 145 146 .if 0 && ${:Uword:u} 147 .endif 148 149 .if 0 && ${:Uword:word=replacement} 150 .endif 151 152 # Before var.c 1.875 from 2021-03-14, Var_Parse returned "${FAIL}else" for the 153 # irrelevant right-hand side of the condition, even though this was not 154 # necessary. Since the return value from Var_Parse is supposed to be ignored 155 # anyway, and since it is actually ignored in an overly complicated way, 156 # an empty string suffices. 157 .MAKEFLAGS: -dcpv 158 .if 0 && ${0:?${FAIL}then:${FAIL}else} 159 .endif 160 161 # The ':L' is applied before the ':?' modifier, giving the expression a name 162 # and a value, just to see whether this value gets passed through or whether 163 # the parse-only mode results in an empty string (only visible in the debug 164 # log). As of var.c 1.875 from 2021-03-14, the value of the variable gets 165 # through, even though an empty string would suffice. 166 DEFINED= defined 167 .if 0 && ${DEFINED:L:?${FAIL}then:${FAIL}else} 168 .endif 169 .MAKEFLAGS: -d0 170 171 all: 172
Indexes created Mon Oct 20 16:09:52 GMT 2025