1 # $NetBSD: varmod-assign.mk,v 1.28 2025/03/30 01:09:41 rillig Exp $ 2 # 3 # Tests for the obscure ::= variable modifiers, which perform variable 4 # assignments during evaluation, just like the = operator in C. 5 6 .if !make(target) 7 8 all: mod-assign-empty-{1,2,3,4} 9 all: mod-assign-parse-{1,2,3} 10 all: mod-assign-shell-error 11 12 # In the following loop expression, 13 # the '::?=' modifier applies the assignment operator '?=' 3 times. The 14 # operator '?=' only has an effect for the first time, therefore the variable 15 # FIRST ends up with the value 1. 16 .if "${1 2 3:L:@i@${FIRST::?=$i}@} first=${FIRST}" != " first=1" 17 . error 18 .endif 19 20 # In the following loop expression, 21 # the modifier '::=' applies the assignment operator '=' 3 times. The 22 # operator '=' overwrites the previous value, therefore the variable LAST ends 23 # up with the value 3. 24 .if "${1 2 3:L:@i@${LAST::=$i}@} last=${LAST}" != " last=3" 25 . error 26 .endif 27 28 # In the following loop expression, 29 # the modifier '::+=' applies the assignment operator '+=' 3 times. The 30 # operator '+=' appends 3 times to the variable, therefore the variable 31 # APPENDED ends up with the value "1 2 3". 32 .if "${1 2 3:L:@i@${APPENDED::+=$i}@} appended=${APPENDED}" != " appended=1 2 3" 33 . error 34 .endif 35 36 # In the following loop expression, 37 # the modifier '::!=' applies the assignment operator '!=' 3 times. Just as 38 # with the modifier '::=', the last value is stored in the RAN variable. 39 .if "${1 2 3:L:@i@${RAN::!=${i:%=echo '<%>';}}@} ran=${RAN}" != " ran=<3>" 40 . error 41 .endif 42 43 # When a '::=' modifier is evaluated as part of an .if condition, it happens 44 # in the command line scope. 45 .if "${FIRST}, ${LAST}, ${APPENDED}, ${RAN}" != "1, 3, 1 2 3, <3>" 46 . error 47 .endif 48 49 # Tests for nested assignments, which are hard to read and therefore seldom 50 # used in practice. 51 52 # The condition "1" is true, therefore THEN1 gets assigned a value, 53 # and the inner IT1 as well. Nothing surprising here. 54 .if "${1:?${THEN1::=then1${IT1::=t1}}:${ELSE1::=else1${IE1::=e1}}} ${THEN1}${ELSE1}${IT1}${IE1}" != " then1t1" 55 . error 56 .endif 57 58 # The condition "0" is false, therefore ELSE2 gets assigned a value, 59 # and the inner IE2 as well. Nothing surprising here as well. 60 .if "${0:?${THEN2::=then2${IT2::=t2}}:${ELSE2::=else2${IE2::=e2}}} ${THEN2}${ELSE2}${IT2}${IE2}" != " else2e2" 61 . error 62 .endif 63 64 # The same effects happen when the variables are defined elsewhere. 65 SINK3:= ${1:?${THEN3::=then3${IT3::=t3}}:${ELSE3::=else3${IE3::=e3}}} ${THEN3}${ELSE3}${IT3}${IE3} 66 SINK4:= ${0:?${THEN4::=then4${IT4::=t4}}:${ELSE4::=else4${IE4::=e4}}} ${THEN4}${ELSE4}${IT4}${IE4} 67 .if ${SINK3} != " then3t3" 68 . error 69 .endif 70 .if ${SINK4} != " else4e4" 71 . error 72 .endif 73 74 mod-assign-empty-1: 75 # Assigning to the empty variable would obviously not work since that 76 # variable is write-protected. 77 # expect: make: Invalid attempt to assign "value" to variable "" via modifier "::=" 78 @echo $@: ${::=value} 79 80 mod-assign-empty-2: 81 # In this variant, it is not as obvious that the name of the 82 # expression is empty. 83 # expect: make: Invalid attempt to assign "overwritten" to variable "" via modifier "::=" 84 @echo $@: ${:Uvalue::=overwritten} 85 86 mod-assign-empty-3: 87 # In this variant, it is not as obvious that the name of the 88 # expression is empty. 89 # expect: make: Invalid attempt to assign "appended" to variable "" via modifier "::+=" 90 @echo $@: ${:Uvalue::+=appended} 91 92 mod-assign-empty-4: 93 # The :L modifier sets the value of the expression to its variable 94 # name. The name of the expression is "VAR", therefore assigning to 95 # that variable works. 96 # expect: mod-assign-empty-4: VAR=overwritten 97 @echo $@: ${VAR:L::=overwritten} VAR=${VAR} 98 99 mod-assign-parse-1: 100 # The modifier for assignment operators starts with a ':'. 101 # An 'x' after that is an invalid modifier. 102 # expect: make: Unknown modifier "::x" 103 @echo ${ASSIGN::x} 104 105 mod-assign-parse-2: 106 # When parsing an assignment operator fails because the operator is 107 # incomplete, make falls back to the SysV modifier. 108 @echo ${SYSV::=sysv\:x}${SYSV::x=:y} 109 110 mod-assign-parse-3: 111 # expect: make: Unfinished modifier after "value # missing closing brace", expecting "}" 112 @echo ${ASSIGN::=value # missing closing brace 113 114 mod-assign-shell-error: 115 # If the command succeeds, the variable is assigned. 116 @${SH_OK::!= echo word; true } echo ok=${SH_OK} 117 118 # If the command fails, the variable keeps its previous value. 119 @${SH_ERR::=previous} 120 @${SH_ERR::!= echo word; (exit 13) } echo err=${SH_ERR} 121 122 # XXX: The ::= modifier expands its right-hand side exactly once. 123 # This differs subtly from normal assignments such as '+=' or '=', which copy 124 # their right-hand side literally. 125 APPEND.prev= previous 126 APPEND.var= ${APPEND.prev} 127 APPEND.indirect= indirect $${:Unot expanded} 128 APPEND.dollar= $${APPEND.indirect} 129 .if ${APPEND.var::+=${APPEND.dollar}} != "" 130 . error 131 .endif 132 .if ${APPEND.var} != "previous indirect \${:Unot expanded}" 133 . error 134 .endif 135 136 137 # The assignment modifier can be used in an expression that is 138 # enclosed in parentheses. In such a case, parsing stops at the first ')', 139 # not at the first '}'. 140 VAR= previous 141 _:= $(VAR::=current}) 142 .if ${VAR} != "current}" 143 . error 144 .endif 145 146 147 # Before var.c 1.888 from 2021-03-15, an expression using the modifier '::=' 148 # expanded its variable name once too often during evaluation. This was only 149 # relevant for variable names containing a '$' sign in their actual name, not 150 # the usual VAR.${param}. 151 .MAKEFLAGS: -dv 152 param= twice 153 VARNAME= VAR.$${param} # Indirect variable name because of the '$', 154 # to avoid difficult escaping rules. 155 156 ${VARNAME}= initial-value # Sets 'VAR.${param}' to 'expanded'. 157 .if defined(VAR.twice) # At this point, the '$$' is not expanded. 158 . error 159 .endif 160 .if ${${VARNAME}::=assigned-value} # Here the variable name gets expanded once 161 . error # too often. 162 .endif 163 .if defined(VAR.twice) 164 . error The variable name in the '::=' modifier is expanded once too often. 165 .endif 166 .if ${${VARNAME}} != "assigned-value" 167 . error 168 .endif 169 .MAKEFLAGS: -d0 170 171 172 # Conditional directives are evaluated in command line scope. An assignment 173 # modifier that creates a new variable creates it in the command line scope. 174 # Existing variables are updated in their previous scope, and environment 175 # variables are created in the global scope, as in other situations. 176 .MAKEFLAGS: CMD_CMD_VAR=cmd-value 177 CMD_GLOBAL_VAR=global-value 178 export CMD_ENV_VAR=env-value 179 .MAKEFLAGS: -dv 180 # expect-reset 181 # expect: Command: CMD_CMD_VAR = new-value 182 # expect: Global: CMD_GLOBAL_VAR = new-value 183 # expect: Global: CMD_ENV_VAR = new-value 184 # expect: Global: ignoring delete 'CMD_NEW_VAR' as it is not found 185 # expect: Command: CMD_NEW_VAR = new-value 186 .if ${CMD_CMD_VAR::=new-value} \ 187 || ${CMD_GLOBAL_VAR::=new-value} \ 188 || ${CMD_ENV_VAR::=new-value} \ 189 || "${CMD_NEW_VAR::=new-value}" 190 . error 191 .endif 192 .MAKEFLAGS: -d0 193 194 # Run the 'target' test in a separate sub-make, with reduced debug logging. 195 all: run-target 196 run-target: .PHONY 197 @${MAKE} -r -f ${MAKEFILE} -dv target 2>&1 | grep ': TARGET_' 198 199 .else # make(target) 200 201 # The commands of a target are evaluated in target scope. An assignment 202 # modifier that creates a new variable creates it in the target scope. 203 # Existing variables are updated in their previous scope, and environment 204 # variables are created in the global scope, as in other situations. 205 # 206 # expect: target: TARGET_TARGET_VAR = new-value 207 # expect: Global: TARGET_GLOBAL_VAR = new-value 208 # expect: Global: TARGET_ENV_VAR = new-value 209 # expect: target: TARGET_NEW_VAR = new-value 210 .MAKEFLAGS: TARGET_CMD_VAR=cmd-value 211 TARGET_GLOBAL_VAR=global-value 212 export TARGET_ENV_VAR=env-value 213 target: .PHONY TARGET_TARGET_VAR=target-value 214 : ${TARGET_TARGET_VAR::=new-value} 215 : ${TARGET_CMD_VAR::=new-value} 216 : ${TARGET_GLOBAL_VAR::=new-value} 217 : ${TARGET_ENV_VAR::=new-value} 218 : ${TARGET_NEW_VAR::=new-value} 219 220 .endif 221
Indexes created Tue Sep 23 02:09:52 GMT 2025