133 lines
4.1 KiB
Makefile
133 lines
4.1 KiB
Makefile
# $NetBSD: varmod-loop-varname.mk,v 1.4 2021/12/05 15:01:04 rillig Exp $
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#
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# Tests for the first part of the variable modifier ':@var@...@', which
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# contains the variable name to use during the loop.
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# Force the test results to be independent of the default value of this
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# setting, which is 'yes' for NetBSD's usr.bin/make but 'no' for the bmake
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# distribution and pkgsrc/devel/bmake.
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.MAKE.SAVE_DOLLARS= yes
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# Before 2021-04-04, the name of the loop variable could be generated
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# dynamically. There was no practical use-case for this.
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# Since var.c 1.907 from 2021-04-04, a '$' is no longer allowed in the
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# variable name.
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.if ${:Uone two three:@${:Ubar:S,b,v,}@+${var}+@} != "+one+ +two+ +three+"
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. error
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.else
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. error
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.endif
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# ":::" is a very creative variable name, unlikely to occur 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, therefore
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# the extra indirection via the modifier ':U'.
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.if ${:U1 2 3:@:::@x${${:U\:\:\:}}y@} != "x1y x2y x3y"
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. error
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.endif
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# "@@" is another creative variable name.
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.if ${:U1 2 3:@\@\@@x${@@}y@} != "x1y x2y x3y"
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. error
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.endif
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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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.if ${:U1 2 3:@\\@x${${:Ux:S,x,\\,}}y@} != "x1y x2y x3y"
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. error
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.endif
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# The variable name can technically be empty, and in this situation
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# the variable value cannot be accessed since the empty "variable"
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# is protected to always return an empty string.
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.if ${:U1 2 3:@@x${}y@} != "xy xy xy"
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. error
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.endif
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# The :@ modifier resolves the variables from the replacement text once more
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# than expected. In particular, it resolves _all_ variables from the scope,
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# and not only the loop variable (in this case v).
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SRCS= source
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CFLAGS.source= before
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ALL_CFLAGS:= ${SRCS:@src@${CFLAGS.${src}}@} # note the ':='
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CFLAGS.source+= after
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.if ${ALL_CFLAGS} != "before"
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. error
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.endif
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# In the following example, the modifier ':@' expands the '$$' to '$'. This
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# means that when the resulting expression is evaluated, these resulting '$'
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# will be interpreted as starting a subexpression.
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#
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# The d means direct reference, the i means indirect reference.
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RESOLVE= ${RES1} $${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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.if ${RESOLVE:@v@w${v}w@} != "w1d2d3w w2i3w w1i2d3 2i\${RES3}w w1d2d3 2i\${RES3} 1i\${RES2}w"
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. error
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.endif
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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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# Since var.c 1.907 from 2021-04-04, a '$' is no longer allowed in the
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# variable name.
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.if ${1 2 3:L:@v$@($v)@} != "(1) (2) (3)"
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. error
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.else
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. error
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.endif
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.if ${1 2 3:L:@v$$@($v)@} != "() () ()"
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. error
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.else
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. error
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.endif
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.if ${1 2 3:L:@v$$$@($v)@} != "() () ()"
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. error
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.else
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. error
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.endif
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# It may happen that there are nested :@ modifiers that use the same name for
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# for the loop variable. These modifiers influence each other.
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#
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# As of 2020-10-18, the :@ modifier is implemented by actually setting a
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# variable in the scope of the expression and deleting it again after the
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# loop. This is different from the .for loops, which substitute the variable
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# expression with ${:Uvalue}, leading to different unwanted side effects.
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#
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# To make the behavior more predictable, the :@ modifier should restore the
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# loop variable to the value it had before the loop. This would result in
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# the string "1a b c1 2a b c2 3a b c3", making the two loops independent.
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.if ${:U1 2 3:@i@$i${:Ua b c:@i@$i@}${i:Uu}@} != "1a b cu 2a b cu 3a b cu"
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. error
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.endif
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# During the loop, the variable is actually defined and nonempty.
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# If the loop were implemented in the same way as the .for loop, the variable
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# would be neither defined nor nonempty since all expressions of the form
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# ${var} would have been replaced with ${:Uword} before evaluating them.
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.if defined(var)
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. error
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.endif
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.if ${:Uword:@var@${defined(var):?def:undef} ${empty(var):?empty:nonempty}@} \
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!= "def nonempty"
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. error
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.endif
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.if defined(var)
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. error
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.endif
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all: .PHONY
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