1# $NetBSD: varmod-loop.mk,v 1.2 2020/08/16 12:30:45 rillig Exp $ 2# 3# Tests for the :@var@...${var}...@ variable modifier. 4 5all: mod-loop-varname 6all: mod-loop-resolve 7all: mod-loop-varname-dollar 8all: mod-loop-dollar 9 10# In the :@ modifier, the name of the loop variable can even be generated 11# dynamically. There's no practical use-case for this, and hopefully nobody 12# will ever depend on this, but technically it's possible. 13# Therefore, in -dL mode, this is forbidden, see lint.mk. 14mod-loop-varname: 15 @echo :${:Uone two three:@${:Ubar:S,b,v,}@+${var}+@:Q}: 16 # ":::" is a very creative variable name, unlikely in practice 17 # The expression ${\:\:\:} would not work since backslashes can only 18 # be escaped in the modifiers, but not in the variable name. 19 @echo :${:U1 2 3:@:::@x${${:U\:\:\:}}y@}: 20 # "@@" is another creative variable name. 21 @echo :${:U1 2 3:@\@\@@x${@@}y@}: 22 # Even "@" works as a variable name since the variable is installed 23 # in the "current" scope, which in this case is the one from the 24 # target. 25 @echo :$@: :${:U1 2 3:@\@@x${@}y@}: :$@: 26 # In extreme cases, even the backslash can be used as variable name. 27 # It needs to be doubled though. 28 @echo :${:U1 2 3:@\\@x${${:Ux:S,x,\\,}}y@}: 29 30# The :@ modifier resolves the variables a little more often than expected. 31# In particular, it resolves _all_ variables from the context, and not only 32# the loop variable (in this case v). 33# 34# The d means direct reference, the i means indirect reference. 35RESOLVE= ${RES1} $${RES1} 36RES1= 1d${RES2} 1i$${RES2} 37RES2= 2d${RES3} 2i$${RES3} 38RES3= 3 39 40mod-loop-resolve: 41 @echo $@:${RESOLVE:@v@w${v}w@:Q}: 42 43# Until 2020-07-20, the variable name of the :@ modifier could end with one 44# or two dollar signs, which were silently ignored. 45# There's no point in allowing a dollar sign in that position. 46mod-loop-varname-dollar: 47 @echo $@:${1 2 3:L:@v$@($v)@:Q}. 48 @echo $@:${1 2 3:L:@v$$@($v)@:Q}. 49 @echo $@:${1 2 3:L:@v$$$@($v)@:Q}. 50 51# Demonstrate that it is possible to generate dollar characters using the 52# :@ modifier. 53# 54# These are edge cases that could have resulted in a parse error as well 55# since the $@ at the end could have been interpreted as a variable, which 56# would mean a missing closing @ delimiter. 57mod-loop-dollar: 58 @echo $@:${:U1:@word@${word}$@:Q}: 59 @echo $@:${:U2:@word@$${word}$$@:Q}: 60 @echo $@:${:U3:@word@$$${word}$$$@:Q}: 61 @echo $@:${:U4:@word@$$$${word}$$$$@:Q}: 62 @echo $@:${:U5:@word@$$$$${word}$$$$$@:Q}: 63 @echo $@:${:U6:@word@$$$$$${word}$$$$$$@:Q}: 64