1 files changed, 35 insertions, 0 deletions
diff --git a/contrib/bmake/unit-tests/directive-export.mk b/contrib/bmake/unit-tests/directive-export.mk
new file mode 100644
index 000000000000..40fda0968cb0
--- /dev/null
+++ b/contrib/bmake/unit-tests/directive-export.mk
@@ -0,0 +1,35 @@
+# $NetBSD: directive-export.mk,v 1.6 2020/12/13 01:07:54 rillig Exp $
+#
+# Tests for the .export directive.
+#
+# See also:
+#	directive-misspellings.mk
+
+# TODO: Implementation
+
+INDIRECT=	indirect
+VAR=		value $$ ${INDIRECT}
+
+# Before 2020-12-13, this unusual expression invoked undefined behavior since
+# it accessed out-of-bounds memory via Var_Export -> ExportVar -> MayExport.
+.export ${:U }
+
+# A variable is exported using the .export directive.
+# During that, its value is expanded, just like almost everywhere else.
+.export VAR
+.if ${:!env | grep '^VAR'!} != "VAR=value \$ indirect"
+.  error
+.endif
+
+# Undefining a variable that has been exported implicitly removes it from
+# the environment of all child processes.
+.undef VAR
+.if ${:!env | grep '^VAR' || true!} != ""
+.  error
+.endif
+
+# No argument means to export all variables.
+.export
+
+all:
+	@:;