[src/trunk]: src/usr.bin/make/unit-tests make(1): explain why the dep-var tes...

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

details:   https://anonhg.NetBSD.org/src/rev/98e90410feac
branches:  trunk
changeset: 943948:98e90410feac
user:      rillig <rillig%NetBSD.org@localhost>
date:      Sun Sep 13 20:04:26 2020 +0000

description:
make(1): explain why the dep-var test behaves differently in lint mode

diffstat:

 usr.bin/make/unit-tests/dep-var.mk |  10 +++++++++-
 1 files changed, 9 insertions(+), 1 deletions(-)

diffs (24 lines):

diff -r 30f95a3645f2 -r 98e90410feac usr.bin/make/unit-tests/dep-var.mk
--- a/usr.bin/make/unit-tests/dep-var.mk        Sun Sep 13 19:46:23 2020 +0000
+++ b/usr.bin/make/unit-tests/dep-var.mk        Sun Sep 13 20:04:26 2020 +0000
@@ -1,4 +1,4 @@
-# $NetBSD: dep-var.mk,v 1.4 2020/09/08 05:26:22 rillig Exp $
+# $NetBSD: dep-var.mk,v 1.5 2020/09/13 20:04:26 rillig Exp $
 #
 # Tests for variable references in dependency declarations.
 #
@@ -73,6 +73,14 @@
 # would be interpreted as a dependency operator instead.
 all: $$$$)
 
+# The $$INDIRECT in the following line is treated like the dependency of the
+# "all" target, that is, the "$$I" is first expanded to "$I", and in a second
+# round of expansion, the "$I" expands to nothing since the variable "I" is
+# undefined.
+#
+# Since 2020-09-13, this generates a parse error in lint mode (-dL), but not
+# in normal mode since ParseDoDependency does not handle any errors after
+# calling Var_Parse.
 undef1 def2 a-def2-b 1-2-$$INDIRECT_2-2-1 ${:U\$)}:
        @echo ${.TARGET:Q}