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Diffstat (limited to 'unit-tests/varmod-assign.mk')
| -rw-r--r-- | unit-tests/varmod-assign.mk | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/unit-tests/varmod-assign.mk b/unit-tests/varmod-assign.mk new file mode 100644 index 000000000000..82b7d947c484 --- /dev/null +++ b/unit-tests/varmod-assign.mk @@ -0,0 +1,81 @@ +# $NetBSD: varmod-assign.mk,v 1.6 2020/08/25 21:16:53 rillig Exp $ +# +# Tests for the obscure ::= variable modifiers, which perform variable +# assignments during evaluation, just like the = operator in C. + +all: mod-assign +all: mod-assign-nested +all: mod-assign-empty +all: mod-assign-parse +all: mod-assign-shell-error + +mod-assign: + # The ::?= modifier applies the ?= assignment operator 3 times. + # The ?= operator only has an effect for the first time, therefore + # the variable FIRST ends up with the value 1. + @echo $@: ${1 2 3:L:@i@${FIRST::?=$i}@} first=${FIRST}. + + # The ::= modifier applies the = assignment operator 3 times. + # The = operator overwrites the previous value, therefore the + # variable LAST ends up with the value 3. + @echo $@: ${1 2 3:L:@i@${LAST::=$i}@} last=${LAST}. + + # The ::+= modifier applies the += assignment operator 3 times. + # The += operator appends 3 times to the variable, therefore + # the variable APPENDED ends up with the value "1 2 3". + @echo $@: ${1 2 3:L:@i@${APPENDED::+=$i}@} appended=${APPENDED}. + + # The ::!= modifier applies the != assignment operator 3 times. + # The side effects of the shell commands are visible in the output. + # Just as with the ::= modifier, the last value is stored in the + # RAN variable. + @echo $@: ${echo.1 echo.2 echo.3:L:@i@${RAN::!=${i:C,.*,&; & 1>\&2,:S,., ,g}}@} ran:${RAN}. + + # The assignments happen in the global scope and thus are + # preserved even after the shell command has been run. + @echo $@: global: ${FIRST:Q}, ${LAST:Q}, ${APPENDED:Q}, ${RAN:Q}. + +mod-assign-nested: + # The condition "1" is true, therefore THEN1 gets assigned a value, + # and IT1 as well. Nothing surprising here. + @echo $@: ${1:?${THEN1::=then1${IT1::=t1}}:${ELSE1::=else1${IE1::=e1}}}${THEN1}${ELSE1}${IT1}${IE1} + + # The condition "0" is false, therefore ELSE1 gets assigned a value, + # and IE1 as well. Nothing surprising here as well. + @echo $@: ${0:?${THEN2::=then2${IT2::=t2}}:${ELSE2::=else2${IE2::=e2}}}${THEN2}${ELSE2}${IT2}${IE2} + + # The same effects happen when the variables are defined elsewhere. + @echo $@: ${SINK3:Q} + @echo $@: ${SINK4:Q} +SINK3:= ${1:?${THEN3::=then3${IT3::=t3}}:${ELSE3::=else3${IE3::=e3}}}${THEN3}${ELSE3}${IT3}${IE3} +SINK4:= ${0:?${THEN4::=then4${IT4::=t4}}:${ELSE4::=else4${IE4::=e4}}}${THEN4}${ELSE4}${IT4}${IE4} + +mod-assign-empty: + # Assigning to the empty variable would obviously not work since that variable + # is write-protected. Therefore it is rejected early as a "bad modifier". + @echo ${::=value} + @echo $@: ${:Uvalue::=overwritten} + + # The :L modifier sets the variable's value to its name. + # Since the name is still "VAR", assigning to that variable works. + @echo $@: ${VAR:L::=overwritten} VAR=${VAR} + +mod-assign-parse: + # The modifier for assignment operators starts with a ':'. + # An 'x' after that is an invalid modifier. + @echo ${ASSIGN::x} # 'x' is an unknown assignment operator + + # When parsing an assignment operator fails because the operator is + # incomplete, make falls back to the SysV modifier. + @echo ${SYSV::=sysv\:x}${SYSV::x=:y} + + @echo ${ASSIGN::=value # missing closing brace + +mod-assign-shell-error: + # If the command succeeds, the variable is assigned. + @${SH_OK::!= echo word; true } echo ok=${SH_OK} + + # If the command fails, the variable keeps its previous value. + # FIXME: the error message says: "previous" returned non-zero status + @${SH_ERR::=previous} + @${SH_ERR::!= echo word; false } echo err=${SH_ERR} |