[src/trunk]: src/usr.bin/make/unit-tests make(1): try a bit harder to set the...

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

details:   https://anonhg.NetBSD.org/src/rev/3b93f98169b4
branches:  trunk
changeset: 937640:3b93f98169b4
user:      rillig <rillig%NetBSD.org@localhost>
date:      Sat Aug 22 21:02:56 2020 +0000

description:
make(1): try a bit harder to set the variable with the empty name

There is not only the != assignment operator, but a few others as well.
Especially the += operator is interesting since it has a different code
path.  But all is good.

diffstat:

 usr.bin/make/unit-tests/varname-empty.mk |  6 +++++-
 1 files changed, 5 insertions(+), 1 deletions(-)

diffs (20 lines):

diff -r 62d04320b786 -r 3b93f98169b4 usr.bin/make/unit-tests/varname-empty.mk
--- a/usr.bin/make/unit-tests/varname-empty.mk  Sat Aug 22 20:50:43 2020 +0000
+++ b/usr.bin/make/unit-tests/varname-empty.mk  Sat Aug 22 21:02:56 2020 +0000
@@ -1,4 +1,4 @@
-# $NetBSD: varname-empty.mk,v 1.2 2020/08/22 20:31:50 rillig Exp $
+# $NetBSD: varname-empty.mk,v 1.3 2020/08/22 21:02:56 rillig Exp $
 #
 # Tests for the special variable with the empty name.
 #
@@ -8,6 +8,10 @@
 
 # Until 2020-08-22 it was possible to assign a value to the variable with
 # the empty name, leading to all kinds of unexpected effects.
+?=     default
+#=     assigned        # XXX: probably undefined behavior
++=     appended
+:=     subst
 !=     echo 'value'
 
 # The .for loop expands the expression ${i} to ${:U1}, ${:U2} and so on.