1*6a7405f5SSimon J. Gerraty# $NetBSD: varmod-loop-varname.mk,v 1.12 2025/01/11 20:54:46 rillig Exp $ 2b0c40a00SSimon J. Gerraty# 3b0c40a00SSimon J. Gerraty# Tests for the first part of the variable modifier ':@var@...@', which 4b0c40a00SSimon J. Gerraty# contains the variable name to use during the loop. 5b0c40a00SSimon J. Gerraty 612904384SSimon J. Gerraty# Force the test results to be independent of the default value of this 712904384SSimon J. Gerraty# setting, which is 'yes' for NetBSD's usr.bin/make but 'no' for the bmake 812904384SSimon J. Gerraty# distribution and pkgsrc/devel/bmake. 9b0c40a00SSimon J. Gerraty.MAKE.SAVE_DOLLARS= yes 10b0c40a00SSimon J. Gerraty 11b0c40a00SSimon J. Gerraty 12b0c40a00SSimon J. Gerraty# Before 2021-04-04, the name of the loop variable could be generated 13b0c40a00SSimon J. Gerraty# dynamically. There was no practical use-case for this. 14b0c40a00SSimon J. Gerraty# Since var.c 1.907 from 2021-04-04, a '$' is no longer allowed in the 15b0c40a00SSimon J. Gerraty# variable name. 16*6a7405f5SSimon J. Gerraty# expect+1: In the :@ modifier, the variable name "${:Ubar:S,b,v,}" must not contain a dollar 17b0c40a00SSimon J. Gerraty.if ${:Uone two three:@${:Ubar:S,b,v,}@+${var}+@} != "+one+ +two+ +three+" 18b0c40a00SSimon J. Gerraty. error 1912904384SSimon J. Gerraty.else 2012904384SSimon J. Gerraty. error 21b0c40a00SSimon J. Gerraty.endif 22b0c40a00SSimon J. Gerraty 23b0c40a00SSimon J. Gerraty 24b0c40a00SSimon J. Gerraty# ":::" is a very creative variable name, unlikely to occur in practice. 25b0c40a00SSimon J. Gerraty# The expression ${\:\:\:} would not work since backslashes can only 26b0c40a00SSimon J. Gerraty# be escaped in the modifiers, but not in the variable name, therefore 27b0c40a00SSimon J. Gerraty# the extra indirection via the modifier ':U'. 28b0c40a00SSimon J. Gerraty.if ${:U1 2 3:@:::@x${${:U\:\:\:}}y@} != "x1y x2y x3y" 29b0c40a00SSimon J. Gerraty. error 30b0c40a00SSimon J. Gerraty.endif 31b0c40a00SSimon J. Gerraty 32b0c40a00SSimon J. Gerraty 33b0c40a00SSimon J. Gerraty# "@@" is another creative variable name. 34b0c40a00SSimon J. Gerraty.if ${:U1 2 3:@\@\@@x${@@}y@} != "x1y x2y x3y" 35b0c40a00SSimon J. Gerraty. error 36b0c40a00SSimon J. Gerraty.endif 37b0c40a00SSimon J. Gerraty 38b0c40a00SSimon J. Gerraty 39b0c40a00SSimon J. Gerraty# In extreme cases, even the backslash can be used as variable name. 40b0c40a00SSimon J. Gerraty# It needs to be doubled though. 41b0c40a00SSimon J. Gerraty.if ${:U1 2 3:@\\@x${${:Ux:S,x,\\,}}y@} != "x1y x2y x3y" 42b0c40a00SSimon J. Gerraty. error 43b0c40a00SSimon J. Gerraty.endif 44b0c40a00SSimon J. Gerraty 45b0c40a00SSimon J. Gerraty 46b0c40a00SSimon J. Gerraty# The variable name can technically be empty, and in this situation 47b0c40a00SSimon J. Gerraty# the variable value cannot be accessed since the empty "variable" 48b0c40a00SSimon J. Gerraty# is protected to always return an empty string. 49b0c40a00SSimon J. Gerraty.if ${:U1 2 3:@@x${}y@} != "xy xy xy" 50b0c40a00SSimon J. Gerraty. error 51b0c40a00SSimon J. Gerraty.endif 52b0c40a00SSimon J. Gerraty 53b0c40a00SSimon J. Gerraty 54b0c40a00SSimon J. Gerraty# The :@ modifier resolves the variables from the replacement text once more 55b0c40a00SSimon J. Gerraty# than expected. In particular, it resolves _all_ variables from the scope, 56b0c40a00SSimon J. Gerraty# and not only the loop variable (in this case v). 57b0c40a00SSimon J. GerratySRCS= source 58b0c40a00SSimon J. GerratyCFLAGS.source= before 59b0c40a00SSimon J. GerratyALL_CFLAGS:= ${SRCS:@src@${CFLAGS.${src}}@} # note the ':=' 60b0c40a00SSimon J. GerratyCFLAGS.source+= after 61b0c40a00SSimon J. Gerraty.if ${ALL_CFLAGS} != "before" 62b0c40a00SSimon J. Gerraty. error 63b0c40a00SSimon J. Gerraty.endif 64b0c40a00SSimon J. Gerraty 65b0c40a00SSimon J. Gerraty 66b0c40a00SSimon J. Gerraty# In the following example, the modifier ':@' expands the '$$' to '$'. This 67b0c40a00SSimon J. Gerraty# means that when the resulting expression is evaluated, these resulting '$' 68b0c40a00SSimon J. Gerraty# will be interpreted as starting a subexpression. 69b0c40a00SSimon J. Gerraty# 70b0c40a00SSimon J. Gerraty# The d means direct reference, the i means indirect reference. 71b0c40a00SSimon J. GerratyRESOLVE= ${RES1} $${RES1} 72b0c40a00SSimon J. GerratyRES1= 1d${RES2} 1i$${RES2} 73b0c40a00SSimon J. GerratyRES2= 2d${RES3} 2i$${RES3} 74b0c40a00SSimon J. GerratyRES3= 3 75b0c40a00SSimon J. Gerraty 76b0c40a00SSimon J. Gerraty.if ${RESOLVE:@v@w${v}w@} != "w1d2d3w w2i3w w1i2d3 2i\${RES3}w w1d2d3 2i\${RES3} 1i\${RES2}w" 77b0c40a00SSimon J. Gerraty. error 78b0c40a00SSimon J. Gerraty.endif 79b0c40a00SSimon J. Gerraty 80b0c40a00SSimon J. Gerraty 81b0c40a00SSimon J. Gerraty# Until 2020-07-20, the variable name of the :@ modifier could end with one 82b0c40a00SSimon J. Gerraty# or two dollar signs, which were silently ignored. 83b0c40a00SSimon J. Gerraty# There's no point in allowing a dollar sign in that position. 84b0c40a00SSimon J. Gerraty# Since var.c 1.907 from 2021-04-04, a '$' is no longer allowed in the 85b0c40a00SSimon J. Gerraty# variable name. 86*6a7405f5SSimon J. Gerraty# expect+1: In the :@ modifier, the variable name "v$" must not contain a dollar 87b0c40a00SSimon J. Gerraty.if ${1 2 3:L:@v$@($v)@} != "(1) (2) (3)" 88b0c40a00SSimon J. Gerraty. error 89b0c40a00SSimon J. Gerraty.else 90b0c40a00SSimon J. Gerraty. error 91b0c40a00SSimon J. Gerraty.endif 92*6a7405f5SSimon J. Gerraty# expect+1: In the :@ modifier, the variable name "v$$" must not contain a dollar 93b0c40a00SSimon J. Gerraty.if ${1 2 3:L:@v$$@($v)@} != "() () ()" 94b0c40a00SSimon J. Gerraty. error 95b0c40a00SSimon J. Gerraty.else 96b0c40a00SSimon J. Gerraty. error 97b0c40a00SSimon J. Gerraty.endif 98*6a7405f5SSimon J. Gerraty# expect+1: In the :@ modifier, the variable name "v$$$" must not contain a dollar 99b0c40a00SSimon J. Gerraty.if ${1 2 3:L:@v$$$@($v)@} != "() () ()" 100b0c40a00SSimon J. Gerraty. error 101b0c40a00SSimon J. Gerraty.else 102b0c40a00SSimon J. Gerraty. error 103b0c40a00SSimon J. Gerraty.endif 104b0c40a00SSimon J. Gerraty 105b0c40a00SSimon J. Gerraty 106b0c40a00SSimon J. Gerraty# It may happen that there are nested :@ modifiers that use the same name for 107b0c40a00SSimon J. Gerraty# for the loop variable. These modifiers influence each other. 108b0c40a00SSimon J. Gerraty# 109b0c40a00SSimon J. Gerraty# As of 2020-10-18, the :@ modifier is implemented by actually setting a 110b0c40a00SSimon J. Gerraty# variable in the scope of the expression and deleting it again after the 111d5e0a182SSimon J. Gerraty# loop. This is different from the .for loops, which substitute the 112b0c40a00SSimon J. Gerraty# expression with ${:Uvalue}, leading to different unwanted side effects. 113b0c40a00SSimon J. Gerraty# 114b0c40a00SSimon J. Gerraty# To make the behavior more predictable, the :@ modifier should restore the 115b0c40a00SSimon J. Gerraty# loop variable to the value it had before the loop. This would result in 116b0c40a00SSimon J. Gerraty# the string "1a b c1 2a b c2 3a b c3", making the two loops independent. 117b0c40a00SSimon J. Gerraty.if ${:U1 2 3:@i@$i${:Ua b c:@i@$i@}${i:Uu}@} != "1a b cu 2a b cu 3a b cu" 118b0c40a00SSimon J. Gerraty. error 119b0c40a00SSimon J. Gerraty.endif 120b0c40a00SSimon J. Gerraty 121b0c40a00SSimon J. Gerraty# During the loop, the variable is actually defined and nonempty. 122b0c40a00SSimon J. Gerraty# If the loop were implemented in the same way as the .for loop, the variable 123b0c40a00SSimon J. Gerraty# would be neither defined nor nonempty since all expressions of the form 124b0c40a00SSimon J. Gerraty# ${var} would have been replaced with ${:Uword} before evaluating them. 125b0c40a00SSimon J. Gerraty.if defined(var) 126b0c40a00SSimon J. Gerraty. error 127b0c40a00SSimon J. Gerraty.endif 128b0c40a00SSimon J. Gerraty.if ${:Uword:@var@${defined(var):?def:undef} ${empty(var):?empty:nonempty}@} \ 129b0c40a00SSimon J. Gerraty != "def nonempty" 130b0c40a00SSimon J. Gerraty. error 131b0c40a00SSimon J. Gerraty.endif 132b0c40a00SSimon J. Gerraty.if defined(var) 133b0c40a00SSimon J. Gerraty. error 134b0c40a00SSimon J. Gerraty.endif 135b0c40a00SSimon J. Gerraty 136b0c40a00SSimon J. Gerratyall: .PHONY 137