1 files changed, 22 insertions, 2 deletions
diff --git a/unit-tests/directive-include.mk b/unit-tests/directive-include.mk
index d36914b25a63..a6b300b3d273 100755
--- a/unit-tests/directive-include.mk
+++ b/unit-tests/directive-include.mk
@@ -1,4 +1,4 @@
-# $NetBSD: directive-include.mk,v 1.5 2020/11/21 14:59:11 rillig Exp $
+# $NetBSD: directive-include.mk,v 1.7 2021/12/03 22:48:07 rillig Exp $
 #
 # Tests for the .include directive, which includes another file.
 
@@ -30,5 +30,25 @@
 # As of 2020-11-21, anything after the delimiter '"' is ignored.
 .include "/dev/null" and ignore anything in the rest of the line.
 
+# The filename to be included can contain expressions.
+DEV=	null
+.include "/dev/${DEV}"
+
+# Expressions in double quotes or angle quotes are first parsed naively, to
+# find the closing '"'.  In a second step, the expressions are expanded.  This
+# means that the expressions cannot include the characters '"' or '>'.  This
+# restriction is not practically relevant since the expressions inside
+# '.include' directives are typically kept as simple as possible.
+#
+# If the whole line were expanded before parsing, the filename to be included
+# would be empty, and the closing '"' would be in the trailing part of the
+# line, which is ignored as of 2021-12-03.
+DQUOT=	"
+.include "${DQUOT}"
+
+# When the expression in a filename cannot be evaluated, the failing
+# expression is skipped and the file is included nevertheless.
+# FIXME: Add proper error handling, no file must be included here.
+.include "nonexistent${:U123:Z}.mk"
+
 all:
-	@:;