xref: /freebsd/contrib/bmake/mk/target-flags.mk (revision c60f6422ffae3ea85e7b10bad950ad27c463af18)
1# NAME:
2#	target-flags.mk - target specific flags
3#
4# DESCRIPTION:
5#	Include this macro file after all others in a makefile and
6#	follow it with any target specific flag settings.
7#	For each such variable v in TARGET_FLAG_VARS we set:
8#.nf
9#
10#	_$v := ${$v}
11#	$v = ${${v}_${.TARGET:T}:U${_$v}}
12#.fi
13#
14#	This allows one to do things like:
15#.nf
16#
17#	TARGET_FLAG_VARS= CFLAGS
18#	.include <target-flags.mk>
19#	CFLAGS_fu.o = ${_CFLAGS:N-Wall}
20#.fi
21#
22#	To turn off -Wall for just the target fu.o
23#	Actually CFLAGS is the default value for TARGET_FLAG_VARS.
24#
25# BUGS:
26#	One must be careful to avoid creating circular references in
27#	variables.  The original version of this macro file did
28#	elaborate things with CFLAGS.  The current, simpler
29#	implementation is ultimately more flexible.
30#
31#	It is important that target-flags.mk is included after other
32#	macro files and that target specific flags that may reference
33#	_$v are set after that.
34#
35#	Only works with a make(1) that does nested evaluation correctly.
36
37# RCSid:
38#	$Id: target-flags.mk,v 1.12 2025/08/09 22:42:24 sjg Exp $
39#
40#	@(#) Copyright (c) 1998-2002, Simon J. Gerraty
41#
42#	SPDX-License-Identifier: BSD-2-Clause
43#
44#	Please send copies of changes and bug-fixes to:
45#	sjg@crufty.net
46#
47
48TARGET_FLAG_VARS?= CFLAGS
49.for v in ${TARGET_FLAG_VARS}
50.ifndef _$v
51_$v := ${$v}
52$v  =  ${${v}_${.TARGET:T}:U${_$v}}
53.endif
54.endfor
55
56