[src/trunk]: src/usr.bin/make/unit-tests make(1): add test for the :D modifier

[rillig <rillig%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/137ac3080411
branches:  trunk
changeset: 1013327:137ac3080411
user:      rillig <rillig%NetBSD.org@localhost>
date:      Tue Aug 25 21:58:08 2020 +0000

description:
make(1): add test for the :D modifier

diffstat:

 usr.bin/make/unit-tests/varmod-defined.mk |  23 +++++++++++++++++++++--
 1 files changed, 21 insertions(+), 2 deletions(-)

diffs (34 lines):

diff -r e923ce0d9b7a -r 137ac3080411 usr.bin/make/unit-tests/varmod-defined.mk
--- a/usr.bin/make/unit-tests/varmod-defined.mk Tue Aug 25 21:16:53 2020 +0000
+++ b/usr.bin/make/unit-tests/varmod-defined.mk Tue Aug 25 21:58:08 2020 +0000
@@ -1,9 +1,28 @@
-# $NetBSD: varmod-defined.mk,v 1.2 2020/08/16 14:25:16 rillig Exp $
+# $NetBSD: varmod-defined.mk,v 1.3 2020/08/25 21:58:08 rillig Exp $
 #
 # Tests for the :D variable modifier, which returns the given string
 # if the variable is defined.  It is closely related to the :U modifier.
 
-# TODO: Implementation
+DEF=   defined
+.undef UNDEF
+
+# Since DEF is defined, the value of the expression is "value", not
+# "defined".
+#
+.if ${DEF:Dvalue} != "value"
+.error
+.endif
+
+# Since UNDEF is not defined, the "value" is ignored.  Instead of leaving the
+# expression undefined, it is set to "", exactly to allow the expression to
+# be used in .if conditions.  In this place, other undefined expressions
+# would generate an error message.
+# XXX: Ideally the error message would be "undefined variable", but as of
+# 2020-08-25 it is "Malformed conditional".
+#
+.if ${UNDEF:Dvalue} != ""
+.error
+.endif
 
 all:
        @:;