diff options
Diffstat (limited to 'contrib/bmake/unit-tests/varmod-loop.mk')
| -rw-r--r-- | contrib/bmake/unit-tests/varmod-loop.mk | 43 |
1 files changed, 41 insertions, 2 deletions
diff --git a/contrib/bmake/unit-tests/varmod-loop.mk b/contrib/bmake/unit-tests/varmod-loop.mk index 561f4b95baa0..a3fbbfceae8d 100644 --- a/contrib/bmake/unit-tests/varmod-loop.mk +++ b/contrib/bmake/unit-tests/varmod-loop.mk @@ -1,4 +1,4 @@ -# $NetBSD: varmod-loop.mk,v 1.2 2020/08/16 12:30:45 rillig Exp $ +# $NetBSD: varmod-loop.mk,v 1.5 2020/10/31 12:34:03 rillig Exp $ # # Tests for the :@var@...${var}...@ variable modifier. @@ -13,20 +13,29 @@ all: mod-loop-dollar # Therefore, in -dL mode, this is forbidden, see lint.mk. mod-loop-varname: @echo :${:Uone two three:@${:Ubar:S,b,v,}@+${var}+@:Q}: - # ":::" is a very creative variable name, unlikely in practice + + # ":::" is a very creative variable name, unlikely in practice. # The expression ${\:\:\:} would not work since backslashes can only # be escaped in the modifiers, but not in the variable name. @echo :${:U1 2 3:@:::@x${${:U\:\:\:}}y@}: + # "@@" is another creative variable name. @echo :${:U1 2 3:@\@\@@x${@@}y@}: + # Even "@" works as a variable name since the variable is installed # in the "current" scope, which in this case is the one from the # target. @echo :$@: :${:U1 2 3:@\@@x${@}y@}: :$@: + # In extreme cases, even the backslash can be used as variable name. # It needs to be doubled though. @echo :${:U1 2 3:@\\@x${${:Ux:S,x,\\,}}y@}: + # The variable name can technically be empty, and in this situation + # the variable value cannot be accessed since the empty variable is + # protected to always return an empty string. + @echo empty: :${:U1 2 3:@@x${}y@}: + # The :@ modifier resolves the variables a little more often than expected. # In particular, it resolves _all_ variables from the context, and not only # the loop variable (in this case v). @@ -61,3 +70,33 @@ mod-loop-dollar: @echo $@:${:U4:@word@$$$${word}$$$$@:Q}: @echo $@:${:U5:@word@$$$$${word}$$$$$@:Q}: @echo $@:${:U6:@word@$$$$$${word}$$$$$$@:Q}: + +# It may happen that there are nested :@ modifiers that use the same name for +# for the loop variable. These modifiers influence each other. +# +# As of 2020-10-18, the :@ modifier is implemented by actually setting a +# variable in the context of the expression and deleting it again after the +# loop. This is different from the .for loops, which substitute the variable +# expression with ${:Uvalue}, leading to different unwanted side effects. +# +# To make the behavior more predictable, the :@ modifier should restore the +# loop variable to the value it had before the loop. This would result in +# the string "1a b c1 2a b c2 3a b c3", making the two loops independent. +.if ${:U1 2 3:@i@$i${:Ua b c:@i@$i@}${i:Uu}@} != "1a b cu 2a b cu 3a b cu" +. error +.endif + +# During the loop, the variable is actually defined and nonempty. +# If the loop were implemented in the same way as the .for loop, the variable +# would be neither defined nor nonempty since all expressions of the form +# ${var} would have been replaced with ${:Uword} before evaluating them. +.if defined(var) +. error +.endif +.if ${:Uword:@var@${defined(var):?def:undef} ${empty(var):?empty:nonempty}@} \ + != "def nonempty" +. error +.endif +.if defined(var) +. error +.endif |