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+# $NetBSD: varparse-mod.mk,v 1.1 2020/10/02 20:34:59 rillig Exp $
+
+# Tests for parsing variable expressions with modifiers.
+
+# As of 2020-10-02, the below condition does not result in a parse error.
+# The condition contains two separate mistakes.  The first mistake is that
+# the :!cmd! modifier is missing the closing '!'.  The second mistake is that
+# there is a stray '}' at the end of the whole condition.
+#
+# As of 2020-10-02, the actual parse result of this condition is a single
+# variable expression with 2 modifiers. The first modifier is
+# ":!echo "\$VAR"} !".  Afterwards, the parser optionally skips a ':' (at the
+# bottom of ApplyModifiers) and continues with the next modifier, in this case
+# "= "value"", which is interpreted as a SysV substitution modifier with an
+# empty left-hand side, thereby appending the string " "value"" to each word
+# of the expression.
+#
+# As of 2020-10-02, some modifiers ensure that they are followed by either a
+# ':' or the closing brace or parenthesis of the expression.  The modifiers
+# that don't ensure this are (in order of appearance in ApplyModifier):
+#	:@var@replacement@
+#	:_
+#	:L
+#	:P
+#	:!cmd!
+#	:gmtime=...
+#	:localtime=...
+#	:M (because '}' and ')' are treated the same)
+#	:N (because '}' and ')' are treated the same)
+#	:S
+#	:C
+#	:range=...
+# On the other hand, these modifiers ensure that they are followed by a
+# delimiter:
+#	:D
+#	:U
+#	:[...]
+#	:gmtime (if not followed by '=')
+#	:hash (if not followed by '=')
+#	:localtime (if not followed by '=')
+#	:t
+#	:q
+#	:Q
+#	:T
+#	:H
+#	:E
+#	:R
+#	:range (if not followed by '=')
+#	:O
+#	:u
+#	:sh
+# These modifiers don't care since they reach until the closing character
+# of the expression, which is either ')' or '}':
+#	::= (as well as the other assignment modifiers)
+#	:?
+#
+.if ${:!echo "\$VAR"} != "value"}
+.endif
+
+all:
+	@: