64 lines
2.4 KiB
Makefile
64 lines
2.4 KiB
Makefile
# $NetBSD: varmod-loop.mk,v 1.2 2020/08/16 12:30:45 rillig Exp $
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#
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# Tests for the :@var@...${var}...@ variable modifier.
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all: mod-loop-varname
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all: mod-loop-resolve
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all: mod-loop-varname-dollar
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all: mod-loop-dollar
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# In the :@ modifier, the name of the loop variable can even be generated
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# dynamically. There's no practical use-case for this, and hopefully nobody
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# will ever depend on this, but technically it's possible.
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# Therefore, in -dL mode, this is forbidden, see lint.mk.
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mod-loop-varname:
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@echo :${:Uone two three:@${:Ubar:S,b,v,}@+${var}+@:Q}:
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# ":::" is a very creative variable name, unlikely in practice
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# The expression ${\:\:\:} would not work since backslashes can only
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# be escaped in the modifiers, but not in the variable name.
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@echo :${:U1 2 3:@:::@x${${:U\:\:\:}}y@}:
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# "@@" is another creative variable name.
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@echo :${:U1 2 3:@\@\@@x${@@}y@}:
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# Even "@" works as a variable name since the variable is installed
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# in the "current" scope, which in this case is the one from the
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# target.
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@echo :$@: :${:U1 2 3:@\@@x${@}y@}: :$@:
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# In extreme cases, even the backslash can be used as variable name.
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# It needs to be doubled though.
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@echo :${:U1 2 3:@\\@x${${:Ux:S,x,\\,}}y@}:
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# The :@ modifier resolves the variables a little more often than expected.
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# In particular, it resolves _all_ variables from the context, and not only
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# the loop variable (in this case v).
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#
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# The d means direct reference, the i means indirect reference.
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RESOLVE= ${RES1} $${RES1}
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RES1= 1d${RES2} 1i$${RES2}
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RES2= 2d${RES3} 2i$${RES3}
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RES3= 3
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mod-loop-resolve:
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@echo $@:${RESOLVE:@v@w${v}w@:Q}:
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# Until 2020-07-20, the variable name of the :@ modifier could end with one
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# or two dollar signs, which were silently ignored.
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# There's no point in allowing a dollar sign in that position.
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mod-loop-varname-dollar:
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@echo $@:${1 2 3:L:@v$@($v)@:Q}.
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@echo $@:${1 2 3:L:@v$$@($v)@:Q}.
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@echo $@:${1 2 3:L:@v$$$@($v)@:Q}.
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# Demonstrate that it is possible to generate dollar characters using the
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# :@ modifier.
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#
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# These are edge cases that could have resulted in a parse error as well
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# since the $@ at the end could have been interpreted as a variable, which
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# would mean a missing closing @ delimiter.
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mod-loop-dollar:
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@echo $@:${:U1:@word@${word}$@:Q}:
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@echo $@:${:U2:@word@$${word}$$@:Q}:
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@echo $@:${:U3:@word@$$${word}$$$@:Q}:
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@echo $@:${:U4:@word@$$$${word}$$$$@:Q}:
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@echo $@:${:U5:@word@$$$$${word}$$$$$@:Q}:
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@echo $@:${:U6:@word@$$$$$${word}$$$$$$@:Q}:
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