[src/trunk]: src/usr.bin/make Document quirks of target local variable assign...

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

details:   https://anonhg.NetBSD.org/src/rev/42c067228739
branches:  trunk
changeset: 359871:42c067228739
user:      sjg <sjg%NetBSD.org@localhost>
date:      Sat Jan 29 07:42:10 2022 +0000

description:
Document quirks of target local variable assignments

diffstat:

 usr.bin/make/make.1 |  14 ++++++++++++--
 1 files changed, 12 insertions(+), 2 deletions(-)

diffs (35 lines):

diff -r 51b144370622 -r 42c067228739 usr.bin/make/make.1
--- a/usr.bin/make/make.1       Sat Jan 29 01:19:30 2022 +0000
+++ b/usr.bin/make/make.1       Sat Jan 29 07:42:10 2022 +0000
@@ -1,4 +1,4 @@
-.\"    $NetBSD: make.1,v 1.302 2022/01/27 06:02:59 sjg Exp $
+.\"    $NetBSD: make.1,v 1.303 2022/01/29 07:42:10 sjg Exp $
 .\"
 .\" Copyright (c) 1990, 1993
 .\"    The Regents of the University of California.  All rights reserved.
@@ -29,7 +29,7 @@
 .\"
 .\"    from: @(#)make.1        8.4 (Berkeley) 3/19/94
 .\"
-.Dd January 21, 2022
+.Dd January 28, 2022
 .Dt MAKE 1
 .Os
 .Sh NAME
@@ -711,6 +711,16 @@
 simply enabling/disabling any of the wrappers will not render all
 of those targets out-of-date.
 .Pp
+.Em NOTE :
+target local variable assignments behave differently in that;
+.Bl -tag -width Ds -offset indent
+.It Ic \&+=
+Only behaves as expected, if there is a previous
+local assignment for the same target and variable.
+.It Ic \&:=
+Is redundant since, the entire dependency line has already been expanded.
+.El
+.Pp
 The seven built-in local variables are as follows:
 .Bl -tag -width ".ARCHIVE" -offset indent
 .It Va .ALLSRC