# $NetBSD: cond-token-plain.mk,v 1.6 2020/11/15 14:58:14 rillig Exp $
#
# Tests for plain tokens (that is, string literals without quotes)
# in .if conditions.

.MAKEFLAGS: -dc

.if ${:Uvalue} != value
.  error
.endif

# Malformed condition since comment parsing is done in an early phase
# and removes the '#' and everything behind it long before the condition
# parser gets to see it.
#
# XXX: The error message is missing for this malformed condition.
# The right-hand side of the comparison is just a '"', before unescaping.
.if ${:U} != "#hash"
.  error
.endif

# To get a '#' into a condition, it has to be escaped using a backslash.
# This prevents the comment parser from removing it, and in turn, it becomes
# visible to CondParser_String.
.if ${:U\#hash} != "\#hash"
.  error
.endif

# Since 2002-12-30, and still as of 2020-09-11, CondParser_Token handles
# the '#' specially, even though at this point, there should be no need for
# comment handling anymore.  The comments are supposed to be stripped off
# in a very early parsing phase.
#
# See https://gnats.netbsd.org/19596 for example makefiles demonstrating the
# original problems.  This workaround is probably not needed anymore.
#
# XXX: Missing error message for the malformed condition. The right-hand
# side before unescaping is double-quotes, backslash, backslash.
.if ${:U\\} != "\\#hash"
.  error
.endif

# The right-hand side of a comparison is not parsed as a token, therefore
# the code from CondParser_Token does not apply to it.
# TODO: Explain the consequences.
# TODO: Does this mean that more syntactic variants are allowed here?
.if ${:U\#hash} != \#hash
.  error
.endif

# XXX: What is the purpose of treating an escaped '#' in the following
# condition as a comment?  And why only at the beginning of a token,
# just as in the shell?
.if 0 \# This is treated as a comment, but why?
.  error
.endif

# Ah, ok, this can be used to add an end-of-condition comment.  But does
# anybody really use this?  This is neither documented nor obvious since
# the '#' is escaped.  It's much clearer to write a comment in the line
# above the condition.
.if ${0 \# comment :?yes:no} != no
.  error
.endif
.if ${1 \# comment :?yes:no} != yes
.  error
.endif

# Usually there is whitespace around the comparison operator, but this is
# not required.
.if ${UNDEF:Uundefined}!=undefined
.  error
.endif
.if ${UNDEF:U12345}>12345
.  error
.endif
.if ${UNDEF:U12345}<12345
.  error
.endif
.if (${UNDEF:U0})||0
.  error
.endif

# Only the comparison operator terminates the comparison operand, and it's
# a coincidence that the '!' is both used in the '!=' comparison operator
# as well as for negating a comparison result.
#
# The boolean operators '&' and '|' don't terminate a comparison operand.
.if ${:Uvar}&&name != "var&&name"
.  error
.endif
.if ${:Uvar}||name != "var||name"
.  error
.endif

all:
	@:;