 @@ -1,211 +1,230 @@
-# $NetBSD: varmod-sysv.mk,v 1.9 2020/10/31 11:06:24 rillig Exp $
+# $NetBSD: varmod-sysv.mk,v 1.10 2020/11/01 22:10:57 rillig Exp $
+#
 # Tests for the ${VAR:from=to} variable modifier, which replaces the suffix
 # "from" with "to".  It can also use '%' as a wildcard.
+#
 # This modifier is applied when the other modifiers don't match exactly.
+#
 # See ApplyModifier_SysV.
 # A typical use case for the :from=to modifier is conversion of filename
 # extensions.
 .if ${src.c:L:.c=.o} != "src.o"
 .  error
 .endif
 # The modifier applies to each word on its own.
 .if ${one.c two.c three.c:L:.c=.o} != "one.o two.o three.o"
 .  error
 .endif
 # Words that don't match the pattern are passed unmodified.
 .if ${src.c src.h:L:.c=.o} != "src.o src.h"
 .  error
 .endif
 # The :from=to modifier is therefore often combined with the :M modifier.
 .if ${src.c src.h:L:M*.c:.c=.o} != "src.o"
 .  error
 .endif
 # Another use case for the :from=to modifier is to append a suffix to each
 # word.  In this case, the "from" string is empty, therefore it always
 # matches.  The same effect can be achieved with the :S,$,teen, modifier.
 .if ${four six seven nine:L:=teen} != "fourteen sixteen seventeen nineteen"
 .  error
 .endif
 # The :from=to modifier can also be used to surround each word by strings.
 # It might be tempting to use this for enclosing a string in quotes for the
 # shell, but that's the job of the :Q modifier.
 .if ${one two three:L:%=(%)} != "(one) (two) (three)"
 .  error
 .endif
 # When the :from=to modifier is parsed, it lasts until the closing brace
 # or parenthesis.  The :Q in the below expression may look like a modifier
 # but isn't.  It is part of the replacement string.
 .if ${a b c d e:L:%a=x:Q} != "x:Q b c d e"
 .  error
 .endif
 # In the :from=to modifier, both parts can contain variable expressions.
 .if ${one two:L:${:Uone}=${:U1}} != "1 two"
 .  error
 .endif
 # In the :from=to modifier, the "from" part is expanded exactly once.
 .if ${:U\$ \$\$ \$\$\$\$:${:U\$\$\$\$}=4} != "\$ \$\$ 4"
 .  error
 .endif
 # In the :from=to modifier, the "to" part is expanded exactly twice.
 # XXX: The right-hand side should be expanded only once.
 # XXX: It's hard to get the escaping correct here, and to read that.
 # XXX: It's not intuitive why the closing brace must be escaped but not
 #      the opening brace.
 .if ${:U1 2 4:4=${:Uonce\${\:Utwice\}}} != "1 2 oncetwice"
 .  error
 .endif
 # The replacement string can contain spaces, thereby changing the number
 # of words in the variable expression.
 .if ${In:L:%=% ${:Uthe Sun}} != "In the Sun"
 .  error
 .endif
 # If the variable is empty, it is debatable whether it consists of a single
 # empty word, or no word at all.  The :from=to modifier treats it as no
 # word at all.
 .if ${:L:=suffix} != ""
 .  error
 .endif
 # Before 2020-07-19, an ampersand could be used in the replacement part
 # of a SysV substitution modifier, and it was replaced with the whole match,
 # just like in the :S modifier.
+#
 # This was probably a copy-and-paste mistake since the code for the SysV
 # modifier looked a lot like the code for the :S and :C modifiers.
 # The ampersand is not mentioned in the manual page.
 .if ${a.bcd.e:L:a.%=%} != "bcd.e"
 .  error
 .endif
 # Before 2020-07-19, the result of the expression was "a.bcd.e".
 .if ${a.bcd.e:L:a.%=&} != "&"
 .  error
 .endif
 # Before 2020-07-20, when a SysV modifier was parsed, a single dollar
 # before the '=' was parsed (but not interpreted) as an anchor.
 # Parsing something without then evaluating it accordingly doesn't make
 # sense.
 .if ${value:L:e$=x} != "value"
 .  error
 .endif
 # Before 2020-07-20, the modifier ":e$=x" was parsed as having a left-hand
 # side "e" and a right-hand side "x".  The dollar was parsed (but not
 # interpreted) as 'anchor at the end'.  Therefore the modifier was equivalent
 # to ":e=x", which doesn't match the string "value$".  Therefore the whole
 # expression evaluated to "value$".
 .if ${${:Uvalue\$}:L:e$=x} != "valux"
 .  error
 .endif
 .if ${value:L:e=x} != "valux"
 .  error
 .endif
 # Words that don't match are copied unmodified.
 .if ${:Ufile.c file.h:%.c=%.cpp} != "file.cpp file.h"
 .  error
 .endif
 # The % placeholder can be anywhere in the string, it doesn't have to be at
 # the beginning of the pattern.
 .if ${:Ufile.c other.c:file.%=renamed.%} != "renamed.c other.c"
 .  error
 .endif
 # It's also possible to modify each word by replacing the prefix and adding
 # a suffix.
 .if ${one two:L:o%=a%w} != "anew two"
 .  error
 .endif
 # Each word gets the suffix "X" appended.
 .if ${one two:L:=X} != "oneX twoX"
 .  error
 .endif
 # The suffix "o" is replaced with "X".
 .if ${one two:L:o=X} != "one twX"
 .  error
 .endif
 # The suffix "o" is replaced with nothing.
 .if ${one two:L:o=} != "one tw"
 .  error
 .endif
 # The suffix "o" is replaced with a literal percent.  The percent is only
 # a wildcard when it appears on the left-hand side.
 .if ${one two:L:o=%} != "one tw%"
 .  error
 .endif
 # Each word with the suffix "o" is replaced with "X".  The percent is a
 # wildcard even though the right-hand side does not contain another percent.
 .if ${one two:L:%o=X} != "one X"
 .  error
 .endif
 # Each word with the prefix "o" is replaced with "X".  The percent is a
 # wildcard even though the right-hand side does not contain another percent.
 .if ${one two:L:o%=X} != "X two"
 .  error
 .endif
 # For each word with the prefix "o" and the suffix "e", the whole word is
 # replaced with "X".
 .if ${one two oe oxen:L:o%e=X} != "X two X oxen"
 .  error
 .endif
 # Only the first '%' is the wildcard.
 .if ${one two o%e other%e:L:o%%e=X} != "one two X X"
 .  error
 .endif
 # In the replacement, only the first '%' is the placeholder, all others
 # are literal percent characters.
 .if ${one two:L:%=%%} != "one% two%"
 .  error
 .endif
 # In the word "one", only a prefix of the pattern suffix "nes" matches,
 # the whole word is too short.  Therefore it doesn't match.
 .if ${one two:L:%nes=%xxx} != "one two"
 .  error
 .endif
 # The :from=to modifier can be used to replace both the prefix and a suffix
 # of a word with other strings.  This is not possible with a single :S
 # modifier, and using a :C modifier for the same task looks more complicated
 # in many cases.
 .if ${prefix-middle-suffix:L:prefix-%-suffix=p-%-s} != "p-middle-s"
 .  error
 .endif
 # This is not a SysV modifier since the nested variable expression expands
 # to an empty string.  The '=' in it should be irrelevant during parsing.
 # As of 2020-11-01, this seemingly correct modifier leads to a parse error.
 # XXX
 .if ${word203:L:from${:D=}to}
 .  error
 .endif
 # XXX: This specially constructed case demonstrates that the SysV modifier
 # lasts longer than expected.  The whole expression initially has the value
 # "fromto}...".  The next modifier is a SysV modifier.  ApplyModifier_SysV
 # parses the modifier as "from${:D=}to", ending at the '}'.  Next, the two
 # parts of the modifier are parsed using ParseModifierPart, which scans
 # differently, properly handling nested variable expressions.  The two parts
 # are now "fromto}..." and "replaced".
 .if "${:Ufromto\}...:from${:D=}to}...=replaced}" != "replaced"
 .  error
 .endif
 # As of 2020-10-06, the right-hand side of the SysV modifier is expanded
 # twice.  The first expansion happens in ApplyModifier_SysV, where the
 # modifier is split into its two parts.  The second expansion happens
 # when each word is replaced in ModifyWord_SYSVSubst.
 # XXX: This is unexpected.  Add more test case to demonstrate the effects
 # of removing one of the expansions.
 VALUE=		value
 INDIRECT=	1:${VALUE} 2:$${VALUE} 4:$$$${VALUE}
 .if ${x:L:x=${INDIRECT}} != "1:value 2:value 4:\${VALUE}"
 .  error
 .endif
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