From 12e256c877885a56f1d082463fa86c5de3884304 Mon Sep 17 00:00:00 2001
From: rillig <rillig@NetBSD.org>
Date: Sun, 27 Dec 2020 21:19:13 +0000
Subject: [PATCH] make(1): add more tests for ':=' assignments

---
 usr.bin/make/unit-tests/var-op-expand.mk | 32 +++++++++++++++++++++++-
 1 file changed, 31 insertions(+), 1 deletion(-)

diff --git a/usr.bin/make/unit-tests/var-op-expand.mk b/usr.bin/make/unit-tests/var-op-expand.mk
index 5c5734a53d99..5e928e0451f0 100644
--- a/usr.bin/make/unit-tests/var-op-expand.mk
+++ b/usr.bin/make/unit-tests/var-op-expand.mk
@@ -1,4 +1,4 @@
-# $NetBSD: var-op-expand.mk,v 1.5 2020/12/27 20:45:52 rillig Exp $
+# $NetBSD: var-op-expand.mk,v 1.6 2020/12/27 21:19:13 rillig Exp $
 #
 # Tests for the := variable assignment operator, which expands its
 # right-hand side.
@@ -86,6 +86,36 @@ UNDEF=		Uwas undefined
 .endif
 
 
+# In variable assignments using the ':=' operator, undefined variables are
+# preserved, no matter how indirectly they are referenced.
+.undef REF3
+REF2=		<${REF3}>
+REF=		${REF2}
+VAR:=		${REF}
+REF3=		too late
+.if ${VAR} != "<too late>"
+.  error
+.endif
+
+
+# In variable assignments using the ':=' operator, '$$' are preserved, no
+# matter how indirectly they are referenced.
+REF2=		REF2:$$ $$$$
+REF=		REF:$$ $$$$ ${REF2}
+VAR:=		VAR:$$ $$$$ ${REF}
+.if ${VAR} != "VAR:\$ \$\$ REF:\$ \$\$ REF2:\$ \$\$"
+.  error
+.endif
+
+
+# In variable assignments using the ':=' operator, '$$' are preserved in the
+# expressions of the top level, but not in expressions that are nested.
+VAR:=		top:$$ ${:Unest1\:\$\$} ${:Unest2${:U\:\$\$}}
+.if ${VAR} != "top:\$ nest1:\$ nest2:\$"
+.  error
+.endif
+
+
 # XXX: edge case: When a variable name refers to an undefined variable, the
 # behavior differs between the '=' and the ':=' assignment operators.
 # This bug exists since var.c 1.42 from 2000-05-11.