Import bmake-20200629vendor/NetBSD/bmake/20200629

from ChangeLog:

    o cond.c: do not eval unnecessary terms of conditionals.

    o meta.c: report error if lseek in filemon_read fails

    o str.c: performance improvement for Str_Match for multiple '*'

    o dieQuietly: supress the failure output from make
    when failing node is a sub-make or a sibling failed.
    This cuts down greatly on unhelpful noise at the end of
    build log.  Disabled by -dj or .MAKE.DIE_QUIETLY=no

    o unit test for :Or

32 files changed, 971 insertions, 733 deletions

diff --git a/ChangeLog b/ChangeLog
index 68b1826ea2aa..ae57f180d82c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,42 @@
+2020-06-29  Simon J Gerraty  <sjg@beast.crufty.net>
+
+	* VERSION (_MAKE_VERSION): 20200629
+	Merge with NetBSD make, pick up
+	o cond.c: do not eval unnecessary terms of conditionals.
+
+2020-06-25  Simon J Gerraty  <sjg@beast.crufty.net>
+
+	* VERSION (_MAKE_VERSION): 20200625
+	Merge with NetBSD make, pick up
+	o meta.c: report error if lseek in filemon_read fails
+
+2020-06-22  Simon J Gerraty  <sjg@beast.crufty.net>
+
+	* VERSION (_MAKE_VERSION): 20200622
+	Merge with NetBSD make, pick up
+	o dieQuietly: ignore OP_SUBMAKE as too aggressive
+
+2020-06-19  Simon J Gerraty  <sjg@beast.crufty.net>
+
+	* VERSION (_MAKE_VERSION): 20200619
+	Merge with NetBSD make, pick up
+	o str.c: performance improvement for Str_Match for multiple '*'
+	o dieQuietly: supress the failure output from make
+	when failing node is a sub-make or a sibling failed.
+	This cuts down greatly on unhelpful noise at the end of
+	build log.  Disabled by -dj or .MAKE.DIE_QUIETLY=no
+
+2020-06-10  Simon J Gerraty  <sjg@beast.crufty.net>
+
+	* FILES: add LICENSE to appease some packagers.
+	This is an attempt to fairly represent the license on almost
+	200 files, which are almost all BSD-3-Clause
+	The few exceptions being more liberal.
+
+	* VERSION (_MAKE_VERSION): 20200610
+	Merge with NetBSD make, pick up
+	o unit test for :Or
+
 2020-06-06  Simon J Gerraty  <sjg@beast.crufty.net>
 
 	* VERSION (_MAKE_VERSION): 20200606
diff --git a/FILES b/FILES
index 5dd4eae97b16..0716bffa3c3b 100644
--- a/FILES
+++ b/FILES
@@ -1,5 +1,6 @@
 ChangeLog
 FILES
+LICENSE
 Makefile
 Makefile.config.in
 PSD.doc/Makefile
@@ -107,6 +108,8 @@ unit-tests/cond2.exp
 unit-tests/cond2.mk
 unit-tests/cond-late.mk
 unit-tests/cond-late.exp
+unit-tests/cond-short.mk
+unit-tests/cond-short.exp
 unit-tests/dollar.exp
 unit-tests/dollar.mk
 unit-tests/doterror.exp
diff --git a/LICENSE b/LICENSE
new file mode 100644
index 000000000000..dbad0ec06a4d
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,59 @@
+The individual files in this distribution are copyright their
+original contributors or assignees.
+Including:
+
+    Copyright (c) 1993-2020, Simon J Gerraty
+    Copyright (c) 2009-2016, Juniper Networks, Inc.
+    Copyright (c) 2009, John Birrell.
+    Copyright (c) 1997-2020 The NetBSD Foundation, Inc.
+    Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
+    Copyright (c) 1989 by Berkeley Softworks
+    Copyright (c) 1988, 1989, 1990, 1992, 1993
+    	The Regents of the University of California.
+    Copyright (c) 1988, 1989 by Adam de Boor
+
+With the exception of the GNU configure script, which states:
+
+    # Copyright (C) 1992-1996, 1998-2012 Free Software Foundation, Inc.
+    #
+    # This configure script is free software; the Free Software Foundation
+    # gives unlimited permission to copy, distribute and modify it.
+
+The license for this distribution is considered to be:
+
+    SPDX-License-Identifier: BSD-3-Clause
+
+example (from https://opensource.org/licenses/BSD-3-Clause):
+
+    Copyright <YEAR> <COPYRIGHT HOLDER>
+    
+    Redistribution and use in source and binary forms, with or without
+    modification, are permitted provided that the following conditions
+    are met:
+
+    1. Redistributions of source code must retain the above copyright
+    notice, this list of conditions and the following disclaimer.
+
+    2. Redistributions in binary form must reproduce the above
+    copyright notice, this list of conditions and the following
+    disclaimer in the documentation and/or other materials provided
+    with the distribution.
+
+    3. Neither the name of the copyright holder nor the names of its
+    contributors may be used to endorse or promote products derived
+    from this software without specific prior written permission.
+
+    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
+    CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
+    INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+    MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+    DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS
+    BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+    EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
+    TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+    ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
+    TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+    THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+    SUCH DAMAGE.
+        
diff --git a/VERSION b/VERSION
index 161d8f01ef2c..77ce0141acef 100644
--- a/VERSION
+++ b/VERSION
@@ -1,2 +1,2 @@
 # keep this compatible with sh and make
-_MAKE_VERSION=20200606
+_MAKE_VERSION=20200629
diff --git a/cond.c b/cond.c
index 7c9c96acc83b..27034189bfd7 100644
--- a/cond.c
+++ b/cond.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: cond.c,v 1.75 2017/04/16 20:59:04 riastradh Exp $	*/
+/*	$NetBSD: cond.c,v 1.76 2020/06/28 11:06:26 rillig Exp $	*/
 
 /*
  * Copyright (c) 1988, 1989, 1990 The Regents of the University of California.
@@ -70,14 +70,14 @@
  */
 
 #ifndef MAKE_NATIVE
-static char rcsid[] = "$NetBSD: cond.c,v 1.75 2017/04/16 20:59:04 riastradh Exp $";
+static char rcsid[] = "$NetBSD: cond.c,v 1.76 2020/06/28 11:06:26 rillig Exp $";
 #else
 #include <sys/cdefs.h>
 #ifndef lint
 #if 0
 static char sccsid[] = "@(#)cond.c	8.2 (Berkeley) 1/2/94";
 #else
-__RCSID("$NetBSD: cond.c,v 1.75 2017/04/16 20:59:04 riastradh Exp $");
+__RCSID("$NetBSD: cond.c,v 1.76 2020/06/28 11:06:26 rillig Exp $");
 #endif
 #endif /* not lint */
 #endif
@@ -146,7 +146,7 @@ typedef enum {
  * last two fields are stored in condInvert and condDefProc, respectively.
  */
 static void CondPushBack(Token);
-static int CondGetArg(char **, char **, const char *);
+static int CondGetArg(Boolean, char **, char **, const char *);
 static Boolean CondDoDefined(int, const char *);
 static int CondStrMatch(const void *, const void *);
 static Boolean CondDoMake(int, const char *);
@@ -225,9 +225,6 @@ CondPushBack(Token t)
  * CondGetArg --
  *	Find the argument of a built-in function.
  *
- * Input:
- *	parens		TRUE if arg should be bounded by parens
- *
  * Results:
  *	The length of the argument and the address of the argument.
  *
@@ -238,7 +235,7 @@ CondPushBack(Token t)
  *-----------------------------------------------------------------------
  */
 static int
-CondGetArg(char **linePtr, char **argPtr, const char *func)
+CondGetArg(Boolean doEval, char **linePtr, char **argPtr, const char *func)
 {
     char	  *cp;
     int	    	  argLen;
@@ -290,7 +287,8 @@ CondGetArg(char **linePtr, char **argPtr, const char *func)
 	    int		len;
 	    void	*freeIt;
 
-	    cp2 = Var_Parse(cp, VAR_CMD, VARF_UNDEFERR|VARF_WANTRES,
+	    cp2 = Var_Parse(cp, VAR_CMD, VARF_UNDEFERR|
+			    (doEval ? VARF_WANTRES : 0),
 			    &len, &freeIt);
 	    Buf_AddBytes(&buf, strlen(cp2), cp2);
 	    free(freeIt);
@@ -577,7 +575,7 @@ CondGetString(Boolean doEval, Boolean *quoted, void **freeIt, Boolean strictLHS)
 	    /* if we are in quotes, then an undefined variable is ok */
 	    str = Var_Parse(condExpr, VAR_CMD,
 			    ((!qt && doEval) ? VARF_UNDEFERR : 0) |
-			    VARF_WANTRES, &len, freeIt);
+			    (doEval ? VARF_WANTRES : 0), &len, freeIt);
 	    if (str == var_Error) {
 		if (*freeIt) {
 		    free(*freeIt);
@@ -813,7 +811,7 @@ done:
 }
 
 static int
-get_mpt_arg(char **linePtr, char **argPtr, const char *func MAKE_ATTR_UNUSED)
+get_mpt_arg(Boolean doEval, char **linePtr, char **argPtr, const char *func MAKE_ATTR_UNUSED)
 {
     /*
      * Use Var_Parse to parse the spec in parens and return
@@ -827,7 +825,7 @@ get_mpt_arg(char **linePtr, char **argPtr, const char *func MAKE_ATTR_UNUSED)
     /* We do all the work here and return the result as the length */
     *argPtr = NULL;
 
-    val = Var_Parse(cp - 1, VAR_CMD, VARF_WANTRES, &length, &freeIt);
+    val = Var_Parse(cp - 1, VAR_CMD, doEval ? VARF_WANTRES : 0, &length, &freeIt);
     /*
      * Advance *linePtr to beyond the closing ). Note that
      * we subtract one because 'length' is calculated from 'cp - 1'.
@@ -864,7 +862,7 @@ compare_function(Boolean doEval)
     static const struct fn_def {
 	const char  *fn_name;
 	int         fn_name_len;
-        int         (*fn_getarg)(char **, char **, const char *);
+        int         (*fn_getarg)(Boolean, char **, char **, const char *);
 	Boolean     (*fn_proc)(int, const char *);
     } fn_defs[] = {
 	{ "defined",   7, CondGetArg, CondDoDefined },
@@ -892,7 +890,7 @@ compare_function(Boolean doEval)
 	if (*cp != '(')
 	    break;
 
-	arglen = fn_def->fn_getarg(&cp, &arg, fn_def->fn_name);
+	arglen = fn_def->fn_getarg(doEval, &cp, &arg, fn_def->fn_name);
 	if (arglen <= 0) {
 	    condExpr = cp;
 	    return arglen < 0 ? TOK_ERROR : TOK_FALSE;
@@ -917,7 +915,7 @@ compare_function(Boolean doEval)
      * would be invalid if we did "defined(a)" - so instead treat as an
      * expression.
      */
-    arglen = CondGetArg(&cp, &arg, NULL);
+    arglen = CondGetArg(doEval, &cp, &arg, NULL);
     for (cp1 = cp; isspace(*(unsigned char *)cp1); cp1++)
 	continue;
     if (*cp1 == '=' || *cp1 == '!')
diff --git a/job.c b/job.c
index 0469a20b2e20..feaa3a63029d 100644
--- a/job.c
+++ b/job.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: job.c,v 1.197 2020/02/06 01:13:19 sjg Exp $	*/
+/*	$NetBSD: job.c,v 1.198 2020/06/19 21:17:48 sjg Exp $	*/
 
 /*
  * Copyright (c) 1988, 1989, 1990 The Regents of the University of California.
@@ -70,14 +70,14 @@
  */
 
 #ifndef MAKE_NATIVE
-static char rcsid[] = "$NetBSD: job.c,v 1.197 2020/02/06 01:13:19 sjg Exp $";
+static char rcsid[] = "$NetBSD: job.c,v 1.198 2020/06/19 21:17:48 sjg Exp $";
 #else
 #include <sys/cdefs.h>
 #ifndef lint
 #if 0
 static char sccsid[] = "@(#)job.c	8.2 (Berkeley) 3/19/94";
 #else
-__RCSID("$NetBSD: job.c,v 1.197 2020/02/06 01:13:19 sjg Exp $");
+__RCSID("$NetBSD: job.c,v 1.198 2020/06/19 21:17:48 sjg Exp $");
 #endif
 #endif /* not lint */
 #endif
@@ -1058,10 +1058,11 @@ JobFinish (Job *job, WAIT_T status)
 		    meta_job_error(job, job->node, job->flags, WEXITSTATUS(status));
 		}
 #endif
-		(void)printf("*** [%s] Error code %d%s\n",
-				job->node->name,
-			       WEXITSTATUS(status),
-			       (job->flags & JOB_IGNERR) ? " (ignored)" : "");
+		if (!dieQuietly(job->node, -1))
+		    (void)printf("*** [%s] Error code %d%s\n",
+				 job->node->name,
+				 WEXITSTATUS(status),
+				 (job->flags & JOB_IGNERR) ? " (ignored)" : "");
 		if (job->flags & JOB_IGNERR) {
 		    WAIT_STATUS(status) = 0;
 		} else {
@@ -3039,6 +3040,8 @@ Job_TokenWithdraw(void)
 	/* And put the stopper back */
 	while (write(tokenWaitJob.outPipe, &tok, 1) == -1 && errno == EAGAIN)
 	    continue;
+	if (dieQuietly(NULL, 1))
+	    exit(2);
 	Fatal("A failure has been detected in another branch of the parallel make");
     }
 
diff --git a/main.c b/main.c
index 1756f7a7d32f..3e28bd5bdc15 100644
--- a/main.c
+++ b/main.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: main.c,v 1.274 2020/03/30 02:41:06 sjg Exp $	*/
+/*	$NetBSD: main.c,v 1.276 2020/06/22 20:15:25 sjg Exp $	*/
 
 /*
  * Copyright (c) 1988, 1989, 1990, 1993
@@ -69,7 +69,7 @@
  */
 
 #ifndef MAKE_NATIVE
-static char rcsid[] = "$NetBSD: main.c,v 1.274 2020/03/30 02:41:06 sjg Exp $";
+static char rcsid[] = "$NetBSD: main.c,v 1.276 2020/06/22 20:15:25 sjg Exp $";
 #else
 #include <sys/cdefs.h>
 #ifndef lint
@@ -81,7 +81,7 @@ __COPYRIGHT("@(#) Copyright (c) 1988, 1989, 1990, 1993\
 #if 0
 static char sccsid[] = "@(#)main.c	8.3 (Berkeley) 3/19/94";
 #else
-__RCSID("$NetBSD: main.c,v 1.274 2020/03/30 02:41:06 sjg Exp $");
+__RCSID("$NetBSD: main.c,v 1.276 2020/06/22 20:15:25 sjg Exp $");
 #endif
 #endif /* not lint */
 #endif
@@ -1889,6 +1889,8 @@ void
 Finish(int errors)
 	           	/* number of errors encountered in Make_Make */
 {
+	if (dieQuietly(NULL, -1))
+		exit(2);
 	Fatal("%d error%s", errors, errors == 1 ? "" : "s");
 }
 
@@ -2041,6 +2043,27 @@ addErrorCMD(void *cmdp, void *gnp MAKE_ATTR_UNUSED)
     return 0;
 }
 
+/*
+ * Return true if we should die without noise.
+ * For example our failing child was a sub-make
+ * or failure happend elsewhere.
+ */
+int
+dieQuietly(GNode *gn, int bf)
+{
+    static int quietly = -1;
+
+    if (quietly < 0) {
+	if (DEBUG(JOB) || getBoolean(".MAKE.DIE_QUIETLY", 1) == 0)
+	    quietly = 0;
+	else if (bf >= 0)
+	    quietly = bf;
+	else
+	    quietly = (gn) ? ((gn->type  & (OP_MAKE)) != 0) : 0;
+    }
+    return quietly;
+}
+
 void
 PrintOnError(GNode *gn, const char *s)
 {
@@ -2048,6 +2071,10 @@ PrintOnError(GNode *gn, const char *s)
     char tmp[64];
     char *cp;
 
+    /* we generally want to keep quiet if a sub-make died */
+    if (dieQuietly(gn, -1))
+	return;
+
     if (s)
 	printf("%s", s);
 	
diff --git a/make.h b/make.h
index 4a693f14a153..4057137c7a10 100644
--- a/make.h
+++ b/make.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: make.h,v 1.107 2020/04/03 03:35:16 sjg Exp $	*/
+/*	$NetBSD: make.h,v 1.108 2020/06/19 21:17:48 sjg Exp $	*/
 
 /*
  * Copyright (c) 1988, 1989, 1990, 1993
@@ -503,6 +503,7 @@ void Make_DoAllVar(GNode *);
 Boolean Make_Run(Lst);
 char * Check_Cwd_Cmd(const char *);
 void Check_Cwd(const char **);
+int dieQuietly(GNode *, int);
 void PrintOnError(GNode *, const char *);
 void Main_ExportMAKEFLAGS(Boolean);
 Boolean Main_SetObjdir(const char *, ...) MAKE_ATTR_PRINTFLIKE(1, 2);
diff --git a/meta.c b/meta.c
index ca40c6dd8224..03a67f19e87b 100644
--- a/meta.c
+++ b/meta.c
@@ -1,4 +1,4 @@
-/*      $NetBSD: meta.c,v 1.81 2020/04/03 03:32:28 sjg Exp $ */
+/*      $NetBSD: meta.c,v 1.82 2020/06/25 15:45:37 sjg Exp $ */
 
 /*
  * Implement 'meta' mode.
@@ -174,14 +174,18 @@ filemon_read(FILE *mfp, int fd)
 	return 0;
     }
     /* rewind */
-    (void)lseek(fd, (off_t)0, SEEK_SET);
-
-    error = 0;
-    fprintf(mfp, "\n-- filemon acquired metadata --\n");
+    if (lseek(fd, (off_t)0, SEEK_SET) < 0) {
+	error = errno;
+	warn("Could not rewind filemon");
+	fprintf(mfp, "\n");
+    } else {
+	error = 0;
+	fprintf(mfp, "\n-- filemon acquired metadata --\n");
 
-    while ((n = read(fd, buf, sizeof(buf))) > 0) {
-	if ((int)fwrite(buf, 1, n, mfp) < n)
-	    error = EIO;
+	while ((n = read(fd, buf, sizeof(buf))) > 0) {
+	    if ((int)fwrite(buf, 1, n, mfp) < n)
+		error = EIO;
+	}
     }
     fflush(mfp);
     if (close(fd) < 0)
diff --git a/mk/ChangeLog b/mk/ChangeLog
index f061d43949e2..bd8b1b1f5b72 100644
--- a/mk/ChangeLog
+++ b/mk/ChangeLog
@@ -1,3 +1,20 @@
+2020-06-28  Simon J Gerraty  <sjg@beast.crufty.net>
+
+	* sys/*.mk: make it easier for local*sys.mk to customize by
+	using ?=
+
+2020-06-22  Simon J Gerraty  <sjg@beast.crufty.net>
+
+	* gendirdeps.mk (LOCAL_DEPENDS_GUARD): if we don't build at level 0
+	it is much safer to guard local depends with a simple check for
+	.MAKE.LEVEL > 0
+
+2020-06-10  Simon J Gerraty  <sjg@beast.crufty.net>
+
+	* install-mk (MK_VERSION): 20200610
+
+	* mkopt.sh: this needs posix shell so #!/bin/sh should be ok
+
 2020-06-06  Simon J Gerraty  <sjg@beast.crufty.net>
 
 	* install-mk (MK_VERSION): 20200606
diff --git a/mk/FILES b/mk/FILES
index dcd00ec2f581..360fb613a15e 100644
--- a/mk/FILES
+++ b/mk/FILES
@@ -1,5 +1,6 @@
 ChangeLog
 FILES
+LICENSE
 README
 auto.obj.mk
 autoconf.mk
diff --git a/mk/gendirdeps.mk b/mk/gendirdeps.mk
index d402cbcc4765..82618f2225a3 100644
--- a/mk/gendirdeps.mk
+++ b/mk/gendirdeps.mk
@@ -1,4 +1,4 @@
-# $Id: gendirdeps.mk,v 1.42 2020/05/16 23:21:48 sjg Exp $
+# $Id: gendirdeps.mk,v 1.44 2020/06/23 04:21:51 sjg Exp $
 
 # Copyright (c) 2011-2020, Simon J. Gerraty
 # Copyright (c) 2010-2018, Juniper Networks, Inc.
@@ -51,7 +51,7 @@ all:
 _CURDIR ?= ${.CURDIR}
 _OBJDIR ?= ${.OBJDIR}
 _OBJTOP ?= ${OBJTOP}
-_OBJROOT ?= ${OBJROOT:U${_OBJTOP}}
+_OBJROOT ?= ${OBJROOT:U${_OBJTOP:H}}
 .if ${_OBJROOT:M*/}
 _slash=/
 .else
@@ -339,6 +339,12 @@ CAT_DEPEND ?= .depend
 .PHONY: ${_DEPENDFILE}
 .endif
 
+.if ${BUILD_AT_LEVEL0:Uno:tl} == "no"
+LOCAL_DEPENDS_GUARD ?= _{.MAKE.LEVEL} > 0
+.else
+LOCAL_DEPENDS_GUARD ?= _{DEP_RELDIR} == _{_DEP_RELDIR}
+.endif
+
 # 'cat .depend' should suffice, but if we are mixing build modes
 # .depend may contain things we don't want.
 # The sed command at the end of the stream, allows for the filters
@@ -350,7 +356,7 @@ ${_DEPENDFILE}: .NOMETA ${CAT_DEPEND:M.depend} ${META_FILES:O:u:@m@${exists($m):
 	${_include_src_dirdeps} \
 	echo '.include <dirdeps.mk>'; \
 	echo; \
-	echo '.if $${DEP_RELDIR} == $${_DEP_RELDIR}'; \
+	echo '.if ${LOCAL_DEPENDS_GUARD}'; \
 	echo '# local dependencies - needed for -jN in clean tree'; \
 	[ -s ${CAT_DEPEND} ] && { grep : ${CAT_DEPEND} | grep -v '[/\\]'; }; \
 	echo '.endif' ) | sed 's,_\([{(]\),$$\1,g' > $@.new${.MAKE.PID}
diff --git a/mk/install-mk b/mk/install-mk
index 4c29ef294bd6..83542a945cd4 100644
--- a/mk/install-mk
+++ b/mk/install-mk
@@ -55,7 +55,7 @@
 #       Simon J. Gerraty <sjg@crufty.net>
 
 # RCSid:
-#	$Id: install-mk,v 1.172 2020/06/06 22:41:15 sjg Exp $
+#	$Id: install-mk,v 1.173 2020/06/23 04:16:35 sjg Exp $
 #
 #	@(#) Copyright (c) 1994 Simon J. Gerraty
 #
@@ -70,7 +70,7 @@
 #	sjg@crufty.net
 #
 
-MK_VERSION=20200606
+MK_VERSION=20200622
 OWNER=
 GROUP=
 MODE=444
diff --git a/mk/mkopt.sh b/mk/mkopt.sh
index ad58479c2bf0..929a5aa83a66 100755
--- a/mk/mkopt.sh
+++ b/mk/mkopt.sh
@@ -1,7 +1,8 @@
-:
-# $Id: mkopt.sh,v 1.11 2017/03/18 21:36:42 sjg Exp $
+#!/bin/sh
+
+# $Id: mkopt.sh,v 1.12 2020/06/23 04:16:35 sjg Exp $
 #
-#	@(#) Copyright (c) 2014, Simon J. Gerraty
+#	@(#) Copyright (c) 2014, 2020, Simon J. Gerraty
 #
 #	This file is provided in the hope that it will
 #	be of use.  There is absolutely NO WARRANTY.
diff --git a/mk/sys/AIX.mk b/mk/sys/AIX.mk
index a5c49584fe2c..b848d99fb4e8 100644
--- a/mk/sys/AIX.mk
+++ b/mk/sys/AIX.mk
@@ -1,80 +1,80 @@
 #	$NetBSD: sys.mk,v 1.19.2.1 1994/07/26 19:58:31 cgd Exp $
 #	@(#)sys.mk	5.11 (Berkeley) 3/13/91
 
-OS=		AIX
-unix=		We run ${OS}.
-ROOT_GROUP=	system
+OS ?=		AIX
+unix ?=		We run ${OS}.
+ROOT_GROUP ?=	system
 
 # This needs a lot of work yet...
 
-NOPIC=no	# no shared libs?
+NOPIC ?=no	# no shared libs?
 
 .SUFFIXES: .out .a .ln .o .c ${CXX_SUFFIXES} .F .f .r .y .l .s .S .cl .p .h .sh .m4
 
 .LIBS:		.a
 
-AR=		ar
-ARFLAGS=	rl
-RANLIB=		ranlib
+AR ?=		ar
+ARFLAGS ?=	rl
+RANLIB ?=		ranlib
 
-AS=		as
+AS ?=		as
 AFLAGS=
-COMPILE.s=	${AS} ${AFLAGS}
-LINK.s=		${CC} ${AFLAGS} ${LDFLAGS}
-COMPILE.S=	${CC} ${AFLAGS} ${CPPFLAGS} -c
-LINK.S=		${CC} ${AFLAGS} ${CPPFLAGS} ${LDFLAGS}
+COMPILE.s ?=	${AS} ${AFLAGS}
+LINK.s ?=		${CC} ${AFLAGS} ${LDFLAGS}
+COMPILE.S ?=	${CC} ${AFLAGS} ${CPPFLAGS} -c
+LINK.S ?=		${CC} ${AFLAGS} ${CPPFLAGS} ${LDFLAGS}
 .if exists(/usr/local/bin/gcc)
-CC=		gcc
-DBG=		-O -g
-STATIC?=		-static
+CC ?=		gcc
+DBG ?=		-O -g
+STATIC ?=		-static
 .else
-CC=             cc 
-DBG=         -g
-STATIC=         
+CC ?=             cc 
+DBG ?=         -g
+STATIC ?=         
 .endif
-CFLAGS=		${DBG}
-COMPILE.c=	${CC} ${CFLAGS} ${CPPFLAGS} -c
-LINK.c=		${CC} ${CFLAGS} ${CPPFLAGS} ${LDFLAGS}
+CFLAGS ?=		${DBG}
+COMPILE.c ?=	${CC} ${CFLAGS} ${CPPFLAGS} -c
+LINK.c ?=		${CC} ${CFLAGS} ${CPPFLAGS} ${LDFLAGS}
 
-CXX=		g++
-CXXFLAGS=	${CFLAGS}
-COMPILE.cc=	${CXX} ${CXXFLAGS} ${CPPFLAGS} -c
-LINK.cc=	${CXX} ${CXXFLAGS} ${CPPFLAGS} ${LDFLAGS}
+CXX ?=		g++
+CXXFLAGS ?=	${CFLAGS}
+COMPILE.cc ?=	${CXX} ${CXXFLAGS} ${CPPFLAGS} -c
+LINK.cc ?=	${CXX} ${CXXFLAGS} ${CPPFLAGS} ${LDFLAGS}
 
-CPP=		cpp
+CPP ?=		cpp
 .if defined(DESTDIR)
 CPPFLAGS+=	-nostdinc -idirafter ${DESTDIR}/usr/include
 .endif
 
-MK_DEP=	mkdeps.sh -N
-FC=		f77
-FFLAGS=		-O
+MK_DEP ?=	mkdeps.sh -N
+FC ?=		f77
+FFLAGS ?=		-O
 RFLAGS=
-COMPILE.f=	${FC} ${FFLAGS} -c
-LINK.f=		${FC} ${FFLAGS} ${LDFLAGS}
-COMPILE.F=	${FC} ${FFLAGS} ${CPPFLAGS} -c
-LINK.F=		${FC} ${FFLAGS} ${CPPFLAGS} ${LDFLAGS}
-COMPILE.r=	${FC} ${FFLAGS} ${RFLAGS} -c
-LINK.r=		${FC} ${FFLAGS} ${RFLAGS} ${LDFLAGS}
-
-LEX=		lex
+COMPILE.f ?=	${FC} ${FFLAGS} -c
+LINK.f ?=		${FC} ${FFLAGS} ${LDFLAGS}
+COMPILE.F ?=	${FC} ${FFLAGS} ${CPPFLAGS} -c
+LINK.F ?=		${FC} ${FFLAGS} ${CPPFLAGS} ${LDFLAGS}
+COMPILE.r ?=	${FC} ${FFLAGS} ${RFLAGS} -c
+LINK.r ?=		${FC} ${FFLAGS} ${RFLAGS} ${LDFLAGS}
+
+LEX ?=		lex
 LFLAGS=
-LEX.l=		${LEX} ${LFLAGS}
+LEX.l ?=		${LEX} ${LFLAGS}
 
-LD=		ld
+LD ?=		ld
 LDFLAGS=
 
-LINT=		lint
-LINTFLAGS=	-chapbx
+LINT ?=		lint
+LINTFLAGS ?=	-chapbx
 
-PC=		pc
+PC ?=		pc
 PFLAGS=
-COMPILE.p=	${PC} ${PFLAGS} ${CPPFLAGS} -c
-LINK.p=		${PC} ${PFLAGS} ${CPPFLAGS} ${LDFLAGS}
+COMPILE.p ?=	${PC} ${PFLAGS} ${CPPFLAGS} -c
+LINK.p ?=		${PC} ${PFLAGS} ${CPPFLAGS} ${LDFLAGS}
 
-YACC=		yacc
-YFLAGS=		-d
-YACC.y=		${YACC} ${YFLAGS}
+YACC ?=		yacc
+YFLAGS ?=		-d
+YACC.y ?=		${YACC} ${YFLAGS}
 
 # C
 .c:
diff --git a/mk/sys/Darwin.mk b/mk/sys/Darwin.mk
index 6d37127be13f..ea04b416ff3a 100644
--- a/mk/sys/Darwin.mk
+++ b/mk/sys/Darwin.mk
@@ -1,108 +1,108 @@
 #	$NetBSD: Darwin.sys.mk,v 1.3 2003/02/16 09:44:41 grant Exp $
 #	@(#)sys.mk	8.2 (Berkeley) 3/21/94
 
-OS=		Darwin
-unix?=		We run ${OS}.
+OS ?=		Darwin
+unix ?=		We run ${OS}.
 
 .SUFFIXES: .out .a .ln .o .s .S .c .m ${CXX_SUFFIXES} .F .f .r .y .l .cl .p .h
 .SUFFIXES: .sh .m4 .dylib
 
 .LIBS:		.a .dylib
 
-SHLIBEXT =	.dylib
-HOST_LIBEXT =	.dylib
-DSHLIBEXT =	.dylib
+SHLIBEXT  ?=	.dylib
+HOST_LIBEXT  ?=	.dylib
+DSHLIBEXT  ?=	.dylib
 
-AR?=		ar
-ARFLAGS?=	rl
+AR ?=		ar
+ARFLAGS ?=	rl
 RANLIB =
 
-AS?=		as
-AFLAGS?=
-COMPILE.s?=	${AS} ${AFLAGS}
-LINK.s?=	${CC} ${AFLAGS} ${LDFLAGS}
-COMPILE.S?=	${CC} ${AFLAGS} ${CPPFLAGS} -c
-LINK.S?=	${CC} ${AFLAGS} ${CPPFLAGS} ${LDFLAGS}
+AS ?=		as
+AFLAGS ?=
+COMPILE.s ?=	${AS} ${AFLAGS}
+LINK.s ?=	${CC} ${AFLAGS} ${LDFLAGS}
+COMPILE.S ?=	${CC} ${AFLAGS} ${CPPFLAGS} -c
+LINK.S ?=	${CC} ${AFLAGS} ${CPPFLAGS} ${LDFLAGS}
 
-PIPE?=		-pipe
+PIPE ?=		-pipe
 
 .if exists(/usr/bin/clang)
-CC?=		cc ${PIPE}
-CXX?=		c++
+CC ?=		cc ${PIPE}
+CXX ?=		c++
 .elif exists(/usr/bin/gcc)
-CC?=		gcc ${PIPE}
+CC ?=		gcc ${PIPE}
 .else
-CC?=		cc ${PIPE}
+CC ?=		cc ${PIPE}
 .endif
-DBG?=		-O2
-CFLAGS?=	${DBG}
-COMPILE.c?=	${CC} ${CFLAGS} ${CPPFLAGS} -c
-LINK.c?=	${CC} ${CFLAGS} ${CPPFLAGS} ${LDFLAGS}
+DBG ?=		-O2
+CFLAGS ?=	${DBG}
+COMPILE.c ?=	${CC} ${CFLAGS} ${CPPFLAGS} -c
+LINK.c ?=	${CC} ${CFLAGS} ${CPPFLAGS} ${LDFLAGS}
 
 .if exists(/usr/bin/g++)
-CXX?=		g++
+CXX ?=		g++
 .else
-CXX?=		c++
+CXX ?=		c++
 .endif
-CXXFLAGS?=	${CFLAGS}
-COMPILE.cc?=	${CXX} ${CXXFLAGS} ${CPPFLAGS} -c
-LINK.cc?=	${CXX} ${CXXFLAGS} ${CPPFLAGS} ${LDFLAGS}
+CXXFLAGS ?=	${CFLAGS}
+COMPILE.cc ?=	${CXX} ${CXXFLAGS} ${CPPFLAGS} -c
+LINK.cc ?=	${CXX} ${CXXFLAGS} ${CPPFLAGS} ${LDFLAGS}
 
-OBJC?=		${CC}
-OBJCFLAGS?=	${CFLAGS}
-COMPILE.m?=	${OBJC} ${OBJCFLAGS} ${CPPFLAGS} -c
-LINK.m?=	${OBJC} ${OBJCFLAGS} ${CPPFLAGS} ${LDFLAGS}
+OBJC ?=		${CC}
+OBJCFLAGS ?=	${CFLAGS}
+COMPILE.m ?=	${OBJC} ${OBJCFLAGS} ${CPPFLAGS} -c
+LINK.m ?=	${OBJC} ${OBJCFLAGS} ${CPPFLAGS} ${LDFLAGS}
 
-CPP?=		cpp
-NOLINT=		1
-CPPFLAGS?=
+CPP ?=		cpp
+NOLINT ?=		1
+CPPFLAGS ?=
 
-MK_DEP?=	mkdep
+MK_DEP ?=	mkdep
 
-FC?=		f77
-FFLAGS?=	-O
-RFLAGS?=
-COMPILE.f?=	${FC} ${FFLAGS} -c
-LINK.f?=	${FC} ${FFLAGS} ${LDFLAGS}
-COMPILE.F?=	${FC} ${FFLAGS} ${CPPFLAGS} -c
-LINK.F?=	${FC} ${FFLAGS} ${CPPFLAGS} ${LDFLAGS}
-COMPILE.r?=	${FC} ${FFLAGS} ${RFLAGS} -c
-LINK.r?=	${FC} ${FFLAGS} ${RFLAGS} ${LDFLAGS}
+FC ?=		f77
+FFLAGS ?=	-O
+RFLAGS ?=
+COMPILE.f ?=	${FC} ${FFLAGS} -c
+LINK.f ?=	${FC} ${FFLAGS} ${LDFLAGS}
+COMPILE.F ?=	${FC} ${FFLAGS} ${CPPFLAGS} -c
+LINK.F ?=	${FC} ${FFLAGS} ${CPPFLAGS} ${LDFLAGS}
+COMPILE.r ?=	${FC} ${FFLAGS} ${RFLAGS} -c
+LINK.r ?=	${FC} ${FFLAGS} ${RFLAGS} ${LDFLAGS}
 
-INSTALL?=	install
+INSTALL ?=	install
 
-LEX?=		lex
-LFLAGS?=
-LEX.l?=		${LEX} ${LFLAGS}
+LEX ?=		lex
+LFLAGS ?=
+LEX.l ?=		${LEX} ${LFLAGS}
 
-LD?=		ld
-LDFLAGS?=
+LD ?=		ld
+LDFLAGS ?=
 
-SHLIB_TEENY = 0
-SHLIB_MINOR = 0
+SHLIB_TEENY  ?= 0
+SHLIB_MINOR  ?= 0
 
-MKPICLIB = no
-LIBEXT = .dylib
+MKPICLIB  ?= no
+LIBEXT  ?= .dylib
 
-LINT?=		lint
-LINTFLAGS?=	-chapbx
+LINT ?=		lint
+LINTFLAGS ?=	-chapbx
 
-LORDER?=	lorder
+LORDER ?=	lorder
 
-NM?=		nm
+NM ?=		nm
 
-PC?=		pc
-PFLAGS?=
-COMPILE.p?=	${PC} ${PFLAGS} ${CPPFLAGS} -c
-LINK.p?=	${PC} ${PFLAGS} ${CPPFLAGS} ${LDFLAGS}
+PC ?=		pc
+PFLAGS ?=
+COMPILE.p ?=	${PC} ${PFLAGS} ${CPPFLAGS} -c
+LINK.p ?=	${PC} ${PFLAGS} ${CPPFLAGS} ${LDFLAGS}
 
-SIZE?=		size
+SIZE ?=		size
 
-TSORT?=		tsort -q
+TSORT ?=		tsort -q
 
-YACC?=		bison -y
-YFLAGS?=	-d
-YACC.y?=	${YACC} ${YFLAGS}
+YACC ?=		bison -y
+YFLAGS ?=	-d
+YACC.y ?=	${YACC} ${YFLAGS}
 
 # C
 .c:
diff --git a/mk/sys/Generic.mk b/mk/sys/Generic.mk
index aa92a6246411..9a3d3bffc183 100644
--- a/mk/sys/Generic.mk
+++ b/mk/sys/Generic.mk
@@ -1,4 +1,4 @@
-#	$Id: Generic.mk,v 1.14 2020/04/17 21:08:17 sjg Exp $
+#	$Id: Generic.mk,v 1.16 2020/06/29 14:34:42 sjg Exp $
 #
 
 # some reasonable defaults
@@ -7,7 +7,7 @@
 
 .LIBS:		.a
 
-tools = \
+tools  ?= \
 	ar \
 	lorder \
 	ranlib \
@@ -27,71 +27,71 @@ MACHINE_ARCH = ${MACHINE_ARCH.${MACHINE}}
 TSORT += -q
 .endif
 
-ARFLAGS?=	rl
+ARFLAGS ?=	rl
 
-AS?=		as
-AFLAGS?=
+AS ?=		as
+AFLAGS ?=
 .if ${MACHINE_ARCH} == "sparc64" 
 AFLAGS+= -Wa,-Av9a
 .endif
-COMPILE.s?=	${CC} ${AFLAGS} -c
-LINK.s?=	${CC} ${AFLAGS} ${LDFLAGS}
-COMPILE.S?=	${CC} ${AFLAGS} ${CPPFLAGS} -c -traditional-cpp
-LINK.S?=	${CC} ${AFLAGS} ${CPPFLAGS} ${LDFLAGS}
-
-CC?=		cc
-DBG?=		-O2
-CFLAGS?=	${DBG}
-COMPILE.c?=	${CC} ${CFLAGS} ${CPPFLAGS} -c
-LINK.c?=	${CC} ${CFLAGS} ${CPPFLAGS} ${LDFLAGS}
-
-CXX?=		c++
-CXXFLAGS?=	${CFLAGS}
-COMPILE.cc?=	${CXX} ${CXXFLAGS} ${CPPFLAGS} -c
-LINK.cc?=	${CXX} ${CXXFLAGS} ${CPPFLAGS} ${LDFLAGS}
-
-OBJC?=		${CC}
-OBJCFLAGS?=	${CFLAGS}
-COMPILE.m?=	${OBJC} ${OBJCFLAGS} ${CPPFLAGS} -c
-LINK.m?=	${OBJC} ${OBJCFLAGS} ${CPPFLAGS} ${LDFLAGS}
-
-CPP?=		cpp
-CPPFLAGS?=	
-
-FC?=		f77
-FFLAGS?=	-O
-RFLAGS?=
-COMPILE.f?=	${FC} ${FFLAGS} -c
-LINK.f?=	${FC} ${FFLAGS} ${LDFLAGS}
-COMPILE.F?=	${FC} ${FFLAGS} ${CPPFLAGS} -c
-LINK.F?=	${FC} ${FFLAGS} ${CPPFLAGS} ${LDFLAGS}
-COMPILE.r?=	${FC} ${FFLAGS} ${RFLAGS} -c
-LINK.r?=	${FC} ${FFLAGS} ${RFLAGS} ${LDFLAGS}
-
-INSTALL?=	install
-
-LEX?=		lex
-LFLAGS?=
-LEX.l?=		${LEX} ${LFLAGS}
-
-LD?=		ld
-LDFLAGS?=
-
-LINT?=		lint
-LINTFLAGS?=	-chapbxzF
-
-NM?=		nm
-
-PC?=		pc
-PFLAGS?=
-COMPILE.p?=	${PC} ${PFLAGS} ${CPPFLAGS} -c
-LINK.p?=	${PC} ${PFLAGS} ${CPPFLAGS} ${LDFLAGS}
-
-SIZE?=		size
-
-YACC?=		yacc
-YFLAGS?=
-YACC.y?=	${YACC} ${YFLAGS}
+COMPILE.s ?=	${CC} ${AFLAGS} -c
+LINK.s ?=	${CC} ${AFLAGS} ${LDFLAGS}
+COMPILE.S ?=	${CC} ${AFLAGS} ${CPPFLAGS} -c -traditional-cpp
+LINK.S ?=	${CC} ${AFLAGS} ${CPPFLAGS} ${LDFLAGS}
+
+CC ?=		cc
+DBG ?=		-O2
+CFLAGS ?=	${DBG}
+COMPILE.c ?=	${CC} ${CFLAGS} ${CPPFLAGS} -c
+LINK.c ?=	${CC} ${CFLAGS} ${CPPFLAGS} ${LDFLAGS}
+
+CXX ?=		c++
+CXXFLAGS ?=	${CFLAGS}
+COMPILE.cc ?=	${CXX} ${CXXFLAGS} ${CPPFLAGS} -c
+LINK.cc ?=	${CXX} ${CXXFLAGS} ${CPPFLAGS} ${LDFLAGS}
+
+OBJC ?=		${CC}
+OBJCFLAGS ?=	${CFLAGS}
+COMPILE.m ?=	${OBJC} ${OBJCFLAGS} ${CPPFLAGS} -c
+LINK.m ?=	${OBJC} ${OBJCFLAGS} ${CPPFLAGS} ${LDFLAGS}
+
+CPP ?=		cpp
+CPPFLAGS ?=	
+
+FC ?=		f77
+FFLAGS ?=	-O
+RFLAGS ?=
+COMPILE.f ?=	${FC} ${FFLAGS} -c
+LINK.f ?=	${FC} ${FFLAGS} ${LDFLAGS}
+COMPILE.F ?=	${FC} ${FFLAGS} ${CPPFLAGS} -c
+LINK.F ?=	${FC} ${FFLAGS} ${CPPFLAGS} ${LDFLAGS}
+COMPILE.r ?=	${FC} ${FFLAGS} ${RFLAGS} -c
+LINK.r ?=	${FC} ${FFLAGS} ${RFLAGS} ${LDFLAGS}
+
+INSTALL ?=	install
+
+LEX ?=		lex
+LFLAGS ?=
+LEX.l ?=		${LEX} ${LFLAGS}
+
+LD ?=		ld
+LDFLAGS ?=
+
+LINT ?=		lint
+LINTFLAGS ?=	-chapbxzF
+
+NM ?=		nm
+
+PC ?=		pc
+PFLAGS ?=
+COMPILE.p ?=	${PC} ${PFLAGS} ${CPPFLAGS} -c
+LINK.p ?=	${PC} ${PFLAGS} ${CPPFLAGS} ${LDFLAGS}
+
+SIZE ?=		size
+
+YACC ?=		yacc
+YFLAGS ?=
+YACC.y ?=	${YACC} ${YFLAGS}
 
 # C
 .c:
diff --git a/mk/sys/HP-UX.mk b/mk/sys/HP-UX.mk
index ac5ce37b85fc..34dd2881d83d 100644
--- a/mk/sys/HP-UX.mk
+++ b/mk/sys/HP-UX.mk
@@ -1,122 +1,122 @@
-#	$Id: HP-UX.mk,v 1.12 2020/04/17 21:08:17 sjg Exp $
+#	$Id: HP-UX.mk,v 1.14 2020/06/29 14:34:42 sjg Exp $
 #	$NetBSD: sys.mk,v 1.19.2.1 1994/07/26 19:58:31 cgd Exp $
 #	@(#)sys.mk	5.11 (Berkeley) 3/13/91
 
-OS=		HP-UX
-ROOT_GROUP=	root
-unix?=		We run ${OS}.
+OS ?=		HP-UX
+ROOT_GROUP ?=	root
+unix ?=		We run ${OS}.
 
 # HP-UX's cc does not provide any clues as to wether this is 9.x or 10.x
 # nor does sys/param.h, so we'll use the existence of /hp-ux
 .if exists("/hp-ux") 
-OSMAJOR?=9
+OSMAJOR ?=9
 .endif
-OSMAJOR?=10
-__HPUX_VERSION?=${OSMAJOR}
+OSMAJOR ?=10
+__HPUX_VERSION ?=${OSMAJOR}
 
 .SUFFIXES: .out .a .ln .o .c ${CXX_SUFFIXES} .F .f .r .y .l .s .S .cl .p .h .sh .m4
 
-LIBMODE= 755
-LIBCRT0=	/lib/crt0.o
+LIBMODE ?= 755
+LIBCRT0 ?=	/lib/crt0.o
 
 .LIBS:		.a
 
 # +b<path> is needed to stop the binaries from insisting on having
 #	the build tree available :-)
 # +s	tells the dynamic loader to use SHLIB_PATH if set
-LD_bpath?=-Wl,+b/lib:/usr/lib:/usr/local/lib
-LD_spath?=-Wl,+s
+LD_bpath ?=-Wl,+b/lib:/usr/lib:/usr/local/lib
+LD_spath ?=-Wl,+s
 LDADD+= ${LD_bpath} ${LD_spath}
 
 .if exists(/usr/lib/end.o)
 LDADD+= /usr/lib/end.o
 .endif
 
-AR=		ar
-ARFLAGS=	rl
-RANLIB=		:
+AR ?=		ar
+ARFLAGS ?=	rl
+RANLIB ?=		:
 
 AFLAGS=
-COMPILE.s=	${AS} ${AFLAGS}
-LINK.s=		${CC} ${AFLAGS} ${LDFLAGS}
-COMPILE.S=	${CC} ${AFLAGS} ${CPPFLAGS} -c
-LINK.S=		${CC} ${AFLAGS} ${CPPFLAGS} ${LDFLAGS}
+COMPILE.s ?=	${AS} ${AFLAGS}
+LINK.s ?=		${CC} ${AFLAGS} ${LDFLAGS}
+COMPILE.S ?=	${CC} ${AFLAGS} ${CPPFLAGS} -c
+LINK.S ?=		${CC} ${AFLAGS} ${CPPFLAGS} ${LDFLAGS}
 .if exists(/usr/local/bin/gcc)
-PIPE?= -pipe
-CC?=		gcc ${PIPE}
-AS=		gas
-DBG?=		-O -g
-STATIC?=		-static
+PIPE ?= -pipe
+CC ?=		gcc ${PIPE}
+AS ?=		gas
+DBG ?=		-O -g
+STATIC ?=		-static
 .if defined(DESTDIR)
 CPPFLAGS+=	-nostdinc -idirafter ${DESTDIR}/usr/include
 .endif
 .else
 # HP's bundled compiler knows not -g or -O
-AS=		as
-CC=             cc
+AS ?=		as
+CC ?=             cc
 .if exists(/opt/ansic/bin/cc)
-CCMODE?=-Ae +ESlit
-PICFLAG?= +z
+CCMODE ?=-Ae +ESlit
+PICFLAG ?= +z
 LD_x=
-DBG?=-g -O
+DBG ?=-g -O
 .endif
-DBG?=         
-STATIC?=         -Wl,-a,archive
+DBG ?=         
+STATIC ?=         -Wl,-a,archive
 .endif
 .if (${__HPUX_VERSION} == "10")
-CCSOURCE_FLAGS?= -D_HPUX_SOURCE
+CCSOURCE_FLAGS ?= -D_HPUX_SOURCE
 .else
-CCSOURCE_FLAGS?= -D_HPUX_SOURCE -D_INCLUDE_POSIX_SOURCE -D_INCLUDE_XOPEN_SOURCE -D_INCLUDE_XOPEN_SOURCE_EXTENDED
+CCSOURCE_FLAGS ?= -D_HPUX_SOURCE -D_INCLUDE_POSIX_SOURCE -D_INCLUDE_XOPEN_SOURCE -D_INCLUDE_XOPEN_SOURCE_EXTENDED
 .endif
-CFLAGS=		${DBG}
-CFLAGS+= ${CCMODE} -D__hpux__ -D__HPUX_VERSION=${__HPUX_VERSION} ${CCSOURCE_FLAGS}
-COMPILE.c=	${CC} ${CFLAGS} ${CPPFLAGS} -c
-LINK.c=		${CC} ${CFLAGS} ${CPPFLAGS} ${LDFLAGS}
+CFLAGS ?=		${DBG}
+CFLAGS+ ?= ${CCMODE} -D__hpux__ -D__HPUX_VERSION=${__HPUX_VERSION} ${CCSOURCE_FLAGS}
+COMPILE.c ?=	${CC} ${CFLAGS} ${CPPFLAGS} -c
+LINK.c ?=		${CC} ${CFLAGS} ${CPPFLAGS} ${LDFLAGS}
 
-CXX=		g++
-CXXFLAGS=	${CFLAGS}
-COMPILE.cc=	${CXX} ${CXXFLAGS} ${CPPFLAGS} -c
-LINK.cc=	${CXX} ${CXXFLAGS} ${CPPFLAGS} ${LDFLAGS}
+CXX ?=		g++
+CXXFLAGS ?=	${CFLAGS}
+COMPILE.cc ?=	${CXX} ${CXXFLAGS} ${CPPFLAGS} -c
+LINK.cc ?=	${CXX} ${CXXFLAGS} ${CPPFLAGS} ${LDFLAGS}
 
-CPP=		cpp
+CPP ?=		cpp
 
-MK_DEP=	mkdeps.sh -N
-FC=		f77
-FFLAGS=		-O
+MK_DEP ?=	mkdeps.sh -N
+FC ?=		f77
+FFLAGS ?=		-O
 RFLAGS=
-COMPILE.f=	${FC} ${FFLAGS} -c
-LINK.f=		${FC} ${FFLAGS} ${LDFLAGS}
-COMPILE.F=	${FC} ${FFLAGS} ${CPPFLAGS} -c
-LINK.F=		${FC} ${FFLAGS} ${CPPFLAGS} ${LDFLAGS}
-COMPILE.r=	${FC} ${FFLAGS} ${RFLAGS} -c
-LINK.r=		${FC} ${FFLAGS} ${RFLAGS} ${LDFLAGS}
-
-LEX=		lex
+COMPILE.f ?=	${FC} ${FFLAGS} -c
+LINK.f ?=		${FC} ${FFLAGS} ${LDFLAGS}
+COMPILE.F ?=	${FC} ${FFLAGS} ${CPPFLAGS} -c
+LINK.F ?=		${FC} ${FFLAGS} ${CPPFLAGS} ${LDFLAGS}
+COMPILE.r ?=	${FC} ${FFLAGS} ${RFLAGS} -c
+LINK.r ?=		${FC} ${FFLAGS} ${RFLAGS} ${LDFLAGS}
+
+LEX ?=		lex
 LFLAGS=
-LEX.l=		${LEX} ${LFLAGS}
+LEX.l ?=		${LEX} ${LFLAGS}
 
-LD=		ld
+LD ?=		ld
 LDFLAGS=
 
-LINT=		lint
-LINTFLAGS=	-chapbx
+LINT ?=		lint
+LINTFLAGS ?=	-chapbx
 
-PC=		pc
+PC ?=		pc
 PFLAGS=
-COMPILE.p=	${PC} ${PFLAGS} ${CPPFLAGS} -c
-LINK.p=		${PC} ${PFLAGS} ${CPPFLAGS} ${LDFLAGS}
+COMPILE.p ?=	${PC} ${PFLAGS} ${CPPFLAGS} -c
+LINK.p ?=		${PC} ${PFLAGS} ${CPPFLAGS} ${LDFLAGS}
 
 # HP's sh sucks
 ENV=
-MAKE_SHELL=		/bin/ksh
+MAKE_SHELL ?=		/bin/ksh
 
 .if exists(/usr/local/bin/bison)
-YACC=		bison -y
+YACC ?=		bison -y
 .else
-YACC=		yacc
+YACC ?=		yacc
 .endif
-YFLAGS=		-d
-YACC.y=		${YACC} ${YFLAGS}
+YFLAGS ?=		-d
+YACC.y ?=		${YACC} ${YFLAGS}
 
 # C
 .c:
diff --git a/mk/sys/IRIX.mk b/mk/sys/IRIX.mk
index b448fb5720cf..a194c1e78a11 100644
--- a/mk/sys/IRIX.mk
+++ b/mk/sys/IRIX.mk
@@ -7,7 +7,7 @@ OS!=		uname -s
 ROOT_GROUP!=	sed -n /:0:/s/:.*//p /etc/group
 .MAKEOVERRIDES+= OS ROOT_GROUP
 .endif
-unix?=		We run ${OS}.
+unix ?=		We run ${OS}.
 .endif
 
 .SUFFIXES: .out .a .ln .o .s .S .c ${CXX_SUFFIXES} .F .f .r .y .l .cl .p .h
@@ -15,75 +15,75 @@ unix?=		We run ${OS}.
 
 .LIBS:		.a
 
-AR?=		ar
-ARFLAGS?=	rl
-RANLIB?=	ranlib
+AR ?=		ar
+ARFLAGS ?=	rl
+RANLIB ?=	ranlib
 
-AS?=		as
-AFLAGS?=
-COMPILE.s?=	${CC} ${AFLAGS} -c
-LINK.s?=	${CC} ${AFLAGS} ${LDFLAGS}
-COMPILE.S?=	${CC} ${AFLAGS} ${CPPFLAGS} -c -traditional-cpp
-LINK.S?=	${CC} ${AFLAGS} ${CPPFLAGS} ${LDFLAGS}
+AS ?=		as
+AFLAGS ?=
+COMPILE.s ?=	${CC} ${AFLAGS} -c
+LINK.s ?=	${CC} ${AFLAGS} ${LDFLAGS}
+COMPILE.S ?=	${CC} ${AFLAGS} ${CPPFLAGS} -c -traditional-cpp
+LINK.S ?=	${CC} ${AFLAGS} ${CPPFLAGS} ${LDFLAGS}
 
-CC?=		cc
-NOGCCERROR?=	# defined
-DBG?=	-O2
-CFLAGS?=	${DBG}
-COMPILE.c?=	${CC} ${CFLAGS} ${CPPFLAGS} -c
-LINK.c?=	${CC} ${CFLAGS} ${CPPFLAGS} ${LDFLAGS}
+CC ?=		cc
+NOGCCERROR ?=	# defined
+DBG ?=	-O2
+CFLAGS ?=	${DBG}
+COMPILE.c ?=	${CC} ${CFLAGS} ${CPPFLAGS} -c
+LINK.c ?=	${CC} ${CFLAGS} ${CPPFLAGS} ${LDFLAGS}
 
-CXX?=		CC
-CXXFLAGS?=	${CFLAGS}
-COMPILE.cc?=	${CXX} ${CXXFLAGS} ${CPPFLAGS} -c
-LINK.cc?=	${CXX} ${CXXFLAGS} ${CPPFLAGS} ${LDFLAGS}
+CXX ?=		CC
+CXXFLAGS ?=	${CFLAGS}
+COMPILE.cc ?=	${CXX} ${CXXFLAGS} ${CPPFLAGS} -c
+LINK.cc ?=	${CXX} ${CXXFLAGS} ${CPPFLAGS} ${LDFLAGS}
 
-OBJC?=		${CC}
-OBJCFLAGS?=	${CFLAGS}
-COMPILE.m?=	${OBJC} ${OBJCFLAGS} ${CPPFLAGS} -c
-LINK.m?=	${OBJC} ${OBJCFLAGS} ${CPPFLAGS} ${LDFLAGS}
+OBJC ?=		${CC}
+OBJCFLAGS ?=	${CFLAGS}
+COMPILE.m ?=	${OBJC} ${OBJCFLAGS} ${CPPFLAGS} -c
+LINK.m ?=	${OBJC} ${OBJCFLAGS} ${CPPFLAGS} ${LDFLAGS}
 
-CPP?=		CC
-CPPFLAGS?=	
+CPP ?=		CC
+CPPFLAGS ?=	
 
-FC?=		f77
-FFLAGS?=	-O
-RFLAGS?=
-COMPILE.f?=	${FC} ${FFLAGS} -c
-LINK.f?=	${FC} ${FFLAGS} ${LDFLAGS}
-COMPILE.F?=	${FC} ${FFLAGS} ${CPPFLAGS} -c
-LINK.F?=	${FC} ${FFLAGS} ${CPPFLAGS} ${LDFLAGS}
-COMPILE.r?=	${FC} ${FFLAGS} ${RFLAGS} -c
-LINK.r?=	${FC} ${FFLAGS} ${RFLAGS} ${LDFLAGS}
+FC ?=		f77
+FFLAGS ?=	-O
+RFLAGS ?=
+COMPILE.f ?=	${FC} ${FFLAGS} -c
+LINK.f ?=	${FC} ${FFLAGS} ${LDFLAGS}
+COMPILE.F ?=	${FC} ${FFLAGS} ${CPPFLAGS} -c
+LINK.F ?=	${FC} ${FFLAGS} ${CPPFLAGS} ${LDFLAGS}
+COMPILE.r ?=	${FC} ${FFLAGS} ${RFLAGS} -c
+LINK.r ?=	${FC} ${FFLAGS} ${RFLAGS} ${LDFLAGS}
 
-INSTALL?=	${PREFIX}/bin/install-sh
+INSTALL ?=	${PREFIX}/bin/install-sh
 
-LEX?=		lex
-LFLAGS?=
-LEX.l?=		${LEX} ${LFLAGS}
+LEX ?=		lex
+LFLAGS ?=
+LEX.l ?=		${LEX} ${LFLAGS}
 
-LD?=		ld
-LDFLAGS?=
+LD ?=		ld
+LDFLAGS ?=
 
-LINT?=		lint
-LINTFLAGS?=	-chapbxzF
+LINT ?=		lint
+LINTFLAGS ?=	-chapbxzF
 
-LORDER?=	lorder
+LORDER ?=	lorder
 
-NM?=		nm
+NM ?=		nm
 
-PC?=		pc
-PFLAGS?=
-COMPILE.p?=	${PC} ${PFLAGS} ${CPPFLAGS} -c
-LINK.p?=	${PC} ${PFLAGS} ${CPPFLAGS} ${LDFLAGS}
+PC ?=		pc
+PFLAGS ?=
+COMPILE.p ?=	${PC} ${PFLAGS} ${CPPFLAGS} -c
+LINK.p ?=	${PC} ${PFLAGS} ${CPPFLAGS} ${LDFLAGS}
 
-SIZE?=		size
+SIZE ?=		size
 
-TSORT?= 	tsort -q
+TSORT ?= 	tsort -q
 
-YACC?=		yacc
-YFLAGS?=
-YACC.y?=	${YACC} ${YFLAGS}
+YACC ?=		yacc
+YFLAGS ?=
+YACC.y ?=	${YACC} ${YFLAGS}
 
 # C
 .c:
diff --git a/mk/sys/Linux.mk b/mk/sys/Linux.mk
index 978aec098ca3..bf80bb3addce 100644
--- a/mk/sys/Linux.mk
+++ b/mk/sys/Linux.mk
@@ -1,83 +1,83 @@
-#	$Id: Linux.mk,v 1.10 2020/04/17 21:08:17 sjg Exp $
+#	$Id: Linux.mk,v 1.12 2020/06/29 14:34:42 sjg Exp $
 #	$NetBSD: sys.mk,v 1.19.2.1 1994/07/26 19:58:31 cgd Exp $
 #	@(#)sys.mk	5.11 (Berkeley) 3/13/91
 
-OS?=		Linux
-unix?=		We run ${OS}.
+OS ?=		Linux
+unix ?=		We run ${OS}.
 
-ROOT_GROUP=	root
+ROOT_GROUP ?=	root
 
 # would be better to work out where it is...
-LIBCRT0= /dev/null
+LIBCRT0 ?= /dev/null
 
-NEED_SOLINKS=yes
+NEED_SOLINKS ?=yes
 
 .SUFFIXES: .out .a .ln .o .c ${CXX_SUFFIXES} .F .f .r .y .l .s .S .cl .p .h .sh .m4
 
 .LIBS:		.a
 
-AR=		ar
-ARFLAGS=	rl
-RANLIB=		ranlib
+AR ?=		ar
+ARFLAGS ?=	rl
+RANLIB ?=		ranlib
 
-AS=		as
+AS ?=		as
 AFLAGS=
-COMPILE.s=	${AS} ${AFLAGS}
-LINK.s=		${CC} ${AFLAGS} ${LDFLAGS}
-COMPILE.S=	${CC} ${AFLAGS} ${CPPFLAGS} -c
-LINK.S=		${CC} ${AFLAGS} ${CPPFLAGS} ${LDFLAGS}
+COMPILE.s ?=	${AS} ${AFLAGS}
+LINK.s ?=		${CC} ${AFLAGS} ${LDFLAGS}
+COMPILE.S ?=	${CC} ${AFLAGS} ${CPPFLAGS} -c
+LINK.S ?=		${CC} ${AFLAGS} ${CPPFLAGS} ${LDFLAGS}
 .if exists(/usr/local/bin/gcc)
-CC=		gcc -pipe
-DBG=		-O -g
-STATIC?=		-static
+CC ?=		gcc -pipe
+DBG ?=		-O -g
+STATIC ?=		-static
 .else
-CC=             cc -pipe
-DBG=         -g
-STATIC=         -Bstatic
+CC ?=             cc -pipe
+DBG ?=         -g
+STATIC ?=         -Bstatic
 .endif
-CFLAGS=		${DBG}
-COMPILE.c=	${CC} ${CFLAGS} ${CPPFLAGS} -c
-LINK.c=		${CC} ${CFLAGS} ${CPPFLAGS} ${LDFLAGS}
+CFLAGS ?=		${DBG}
+COMPILE.c ?=	${CC} ${CFLAGS} ${CPPFLAGS} -c
+LINK.c ?=		${CC} ${CFLAGS} ${CPPFLAGS} ${LDFLAGS}
 
-CXX=		g++
-CXXFLAGS=	${CFLAGS}
-COMPILE.cc=	${CXX} ${CXXFLAGS} ${CPPFLAGS} -c
-LINK.cc=	${CXX} ${CXXFLAGS} ${CPPFLAGS} ${LDFLAGS}
+CXX ?=		g++
+CXXFLAGS ?=	${CFLAGS}
+COMPILE.cc ?=	${CXX} ${CXXFLAGS} ${CPPFLAGS} -c
+LINK.cc ?=	${CXX} ${CXXFLAGS} ${CPPFLAGS} ${LDFLAGS}
 
-CPP=		cpp
+CPP ?=		cpp
 .if defined(DESTDIR)
 CPPFLAGS+=	-nostdinc -idirafter ${DESTDIR}/usr/include
 .endif
 
-MK_DEP=	mkdeps.sh -N
-FC=		f77
-FFLAGS=		-O
+MK_DEP ?=	mkdeps.sh -N
+FC ?=		f77
+FFLAGS ?=		-O
 RFLAGS=
-COMPILE.f=	${FC} ${FFLAGS} -c
-LINK.f=		${FC} ${FFLAGS} ${LDFLAGS}
-COMPILE.F=	${FC} ${FFLAGS} ${CPPFLAGS} -c
-LINK.F=		${FC} ${FFLAGS} ${CPPFLAGS} ${LDFLAGS}
-COMPILE.r=	${FC} ${FFLAGS} ${RFLAGS} -c
-LINK.r=		${FC} ${FFLAGS} ${RFLAGS} ${LDFLAGS}
-
-LEX=		lex
+COMPILE.f ?=	${FC} ${FFLAGS} -c
+LINK.f ?=		${FC} ${FFLAGS} ${LDFLAGS}
+COMPILE.F ?=	${FC} ${FFLAGS} ${CPPFLAGS} -c
+LINK.F ?=		${FC} ${FFLAGS} ${CPPFLAGS} ${LDFLAGS}
+COMPILE.r ?=	${FC} ${FFLAGS} ${RFLAGS} -c
+LINK.r ?=		${FC} ${FFLAGS} ${RFLAGS} ${LDFLAGS}
+
+LEX ?=		lex
 LFLAGS=
-LEX.l=		${LEX} ${LFLAGS}
+LEX.l ?=		${LEX} ${LFLAGS}
 
-LD=		ld
+LD ?=		ld
 LDFLAGS=
 
-LINT=		lint
-LINTFLAGS=	-chapbx
+LINT ?=		lint
+LINTFLAGS ?=	-chapbx
 
-PC=		pc
+PC ?=		pc
 PFLAGS=
-COMPILE.p=	${PC} ${PFLAGS} ${CPPFLAGS} -c
-LINK.p=		${PC} ${PFLAGS} ${CPPFLAGS} ${LDFLAGS}
+COMPILE.p ?=	${PC} ${PFLAGS} ${CPPFLAGS} -c
+LINK.p ?=		${PC} ${PFLAGS} ${CPPFLAGS} ${LDFLAGS}
 
-YACC=		yacc
-YFLAGS=		-d
-YACC.y=		${YACC} ${YFLAGS}
+YACC ?=		yacc
+YFLAGS ?=		-d
+YACC.y ?=		${YACC} ${YFLAGS}
 
 # C
 .c:
diff --git a/mk/sys/NetBSD.mk b/mk/sys/NetBSD.mk
index a1711a5ec9db..2e72cc742e4f 100644
--- a/mk/sys/NetBSD.mk
+++ b/mk/sys/NetBSD.mk
@@ -1,21 +1,21 @@
 #	$NetBSD: sys.mk,v 1.66.2.1 2002/06/05 03:31:01 lukem Exp $
 #	@(#)sys.mk	8.2 (Berkeley) 3/21/94
 
-OS=		NetBSD
-unix?=		We run ${OS}.
+OS ?=		NetBSD
+unix ?=		We run ${OS}.
 
 .if !defined(MAKE_VERSION)
 # we are running native make
 # which defined MAKE_VERSION between 20010609 and 20090324
 # so we can make a rough guess
 .if defined(.MAKE.LEVEL)
-MAKE_VERSION = 20090908
+MAKE_VERSION  ?= 20090908
 .elif defined(.MAKE.MAKEFILES)
 # introduced 20071008
-MAKE_VERSION = 20090324
+MAKE_VERSION  ?= 20090324
 .else
 # this just before when MAKE_VERSION was introduced
-MAKE_VERSION = 20010606
+MAKE_VERSION  ?= 20010606
 .endif
 .endif
 
@@ -24,29 +24,29 @@ MAKE_VERSION = 20010606
 
 .LIBS:		.a
 
-AR?=		ar
-ARFLAGS?=	rl
-RANLIB?=	ranlib
+AR ?=		ar
+ARFLAGS ?=	rl
+RANLIB ?=	ranlib
 
-AS?=		as
-AFLAGS?=
-COMPILE.s?=	${CC} ${AFLAGS} -c
-LINK.s?=	${CC} ${AFLAGS} ${LDFLAGS}
-COMPILE.S?=	${CC} ${AFLAGS} ${CPPFLAGS} -c -traditional-cpp
-LINK.S?=	${CC} ${AFLAGS} ${CPPFLAGS} ${LDFLAGS}
+AS ?=		as
+AFLAGS ?=
+COMPILE.s ?=	${CC} ${AFLAGS} -c
+LINK.s ?=	${CC} ${AFLAGS} ${LDFLAGS}
+COMPILE.S ?=	${CC} ${AFLAGS} ${CPPFLAGS} -c -traditional-cpp
+LINK.S ?=	${CC} ${AFLAGS} ${CPPFLAGS} ${LDFLAGS}
 
-CC?=		cc
+CC ?=		cc
 
 # need to make sure this is set
 MACHINE_ARCH.${MACHINE} ?= ${MACHINE}
 .if empty(MACHINE_ARCH)
-MACHINE_ARCH = ${MACHINE_ARCH.${MACHINE}}
+MACHINE_ARCH  ?= ${MACHINE_ARCH.${MACHINE}}
 .endif
 
 #
 # CPU model, derived from MACHINE_ARCH
 #
-MACHINE_CPU=	${MACHINE_ARCH:C/mipse[bl]/mips/:C/mips64e[bl]/mips/:C/sh3e[bl]/sh3/:S/m68000/m68k/:S/armeb/arm/}
+MACHINE_CPU ?=	${MACHINE_ARCH:C/mipse[bl]/mips/:C/mips64e[bl]/mips/:C/sh3e[bl]/sh3/:S/m68000/m68k/:S/armeb/arm/}
 
 .if ${MACHINE_CPU} == "alpha" || \
     ${MACHINE_CPU} == "arm" || \
@@ -56,69 +56,69 @@ MACHINE_CPU=	${MACHINE_ARCH:C/mipse[bl]/mips/:C/mips64e[bl]/mips/:C/sh3e[bl]/sh3
     ${MACHINE_CPU} == "powerpc" || \
     ${MACHINE_CPU} == "sparc" || \
     ${MACHINE_CPU} == "vax"
-DBG?=	-O2
+DBG ?=	-O2
 .elif ${MACHINE_ARCH} == "x86_64"
-DBG?=
+DBG ?=
 .elif ${MACHINE_ARCH} == "sparc64"
-DBG?=	-O -ffixed-g4	#Hack for embedany memory model compatibility
+DBG ?=	-O -ffixed-g4	#Hack for embedany memory model compatibility
 .else
-DBG?=	-O
+DBG ?=	-O
 .endif
-CFLAGS?=	${DBG}
-COMPILE.c?=	${CC} ${CFLAGS} ${CPPFLAGS} -c
-LINK.c?=	${CC} ${CFLAGS} ${CPPFLAGS} ${LDFLAGS}
+CFLAGS ?=	${DBG}
+COMPILE.c ?=	${CC} ${CFLAGS} ${CPPFLAGS} -c
+LINK.c ?=	${CC} ${CFLAGS} ${CPPFLAGS} ${LDFLAGS}
 
-CXX?=		c++
-CXXFLAGS?=	${CFLAGS}
-COMPILE.cc?=	${CXX} ${CXXFLAGS} ${CPPFLAGS} -c
-LINK.cc?=	${CXX} ${CXXFLAGS} ${CPPFLAGS} ${LDFLAGS}
+CXX ?=		c++
+CXXFLAGS ?=	${CFLAGS}
+COMPILE.cc ?=	${CXX} ${CXXFLAGS} ${CPPFLAGS} -c
+LINK.cc ?=	${CXX} ${CXXFLAGS} ${CPPFLAGS} ${LDFLAGS}
 
-OBJC?=		${CC}
-OBJCFLAGS?=	${CFLAGS}
-COMPILE.m?=	${OBJC} ${OBJCFLAGS} ${CPPFLAGS} -c
-LINK.m?=	${OBJC} ${OBJCFLAGS} ${CPPFLAGS} ${LDFLAGS}
+OBJC ?=		${CC}
+OBJCFLAGS ?=	${CFLAGS}
+COMPILE.m ?=	${OBJC} ${OBJCFLAGS} ${CPPFLAGS} -c
+LINK.m ?=	${OBJC} ${OBJCFLAGS} ${CPPFLAGS} ${LDFLAGS}
 
-CPP?=		cpp
-CPPFLAGS?=	
+CPP ?=		cpp
+CPPFLAGS ?=	
 
-FC?=		f77
-FFLAGS?=	-O
-RFLAGS?=
-COMPILE.f?=	${FC} ${FFLAGS} -c
-LINK.f?=	${FC} ${FFLAGS} ${LDFLAGS}
-COMPILE.F?=	${FC} ${FFLAGS} ${CPPFLAGS} -c
-LINK.F?=	${FC} ${FFLAGS} ${CPPFLAGS} ${LDFLAGS}
-COMPILE.r?=	${FC} ${FFLAGS} ${RFLAGS} -c
-LINK.r?=	${FC} ${FFLAGS} ${RFLAGS} ${LDFLAGS}
+FC ?=		f77
+FFLAGS ?=	-O
+RFLAGS ?=
+COMPILE.f ?=	${FC} ${FFLAGS} -c
+LINK.f ?=	${FC} ${FFLAGS} ${LDFLAGS}
+COMPILE.F ?=	${FC} ${FFLAGS} ${CPPFLAGS} -c
+LINK.F ?=	${FC} ${FFLAGS} ${CPPFLAGS} ${LDFLAGS}
+COMPILE.r ?=	${FC} ${FFLAGS} ${RFLAGS} -c
+LINK.r ?=	${FC} ${FFLAGS} ${RFLAGS} ${LDFLAGS}
 
-INSTALL?=	install
+INSTALL ?=	install
 
-LEX?=		lex
-LFLAGS?=
-LEX.l?=		${LEX} ${LFLAGS}
+LEX ?=		lex
+LFLAGS ?=
+LEX.l ?=		${LEX} ${LFLAGS}
 
-LD?=		ld
-LDFLAGS?=
+LD ?=		ld
+LDFLAGS ?=
 
-LINT?=		lint
-LINTFLAGS?=	-chapbxzF
+LINT ?=		lint
+LINTFLAGS ?=	-chapbxzF
 
-LORDER?=	lorder
+LORDER ?=	lorder
 
-NM?=		nm
+NM ?=		nm
 
-PC?=		pc
-PFLAGS?=
-COMPILE.p?=	${PC} ${PFLAGS} ${CPPFLAGS} -c
-LINK.p?=	${PC} ${PFLAGS} ${CPPFLAGS} ${LDFLAGS}
+PC ?=		pc
+PFLAGS ?=
+COMPILE.p ?=	${PC} ${PFLAGS} ${CPPFLAGS} -c
+LINK.p ?=	${PC} ${PFLAGS} ${CPPFLAGS} ${LDFLAGS}
 
-SIZE?=		size
+SIZE ?=		size
 
-TSORT?= 	tsort -q
+TSORT ?= 	tsort -q
 
-YACC?=		yacc
-YFLAGS?=
-YACC.y?=	${YACC} ${YFLAGS}
+YACC ?=		yacc
+YFLAGS ?=
+YACC.y ?=	${YACC} ${YFLAGS}
 
 # C
 .c:
diff --git a/mk/sys/OSF1.mk b/mk/sys/OSF1.mk
index 0d0a73f40c98..4c1a09f6f5f7 100644
--- a/mk/sys/OSF1.mk
+++ b/mk/sys/OSF1.mk
@@ -1,15 +1,15 @@
-#	$Id: OSF1.mk,v 1.9 2020/04/17 21:08:17 sjg Exp $
+#	$Id: OSF1.mk,v 1.11 2020/06/29 14:34:42 sjg Exp $
 #	$NetBSD: sys.mk,v 1.19.2.1 1994/07/26 19:58:31 cgd Exp $
 #	@(#)sys.mk	5.11 (Berkeley) 3/13/91
 
-OS?=		OSF1
-unix?=		We run ${OS}.
-ROOT_GROUP=	system
+OS ?=		OSF1
+unix ?=		We run ${OS}.
+ROOT_GROUP ?=	system
 
 # can't fine one anywhere, so just stop the dependency
-LIBCRT0= /dev/null
+LIBCRT0 ?= /dev/null
 
-PATH=/usr/sbin:/usr/bin:/usr/ucb:/opt/gnu/bin:/usr/ccs/bin
+PATH ?=/usr/sbin:/usr/bin:/usr/ucb:/opt/gnu/bin:/usr/ccs/bin
 
 .SUFFIXES: .out .a .ln .o .c ${CXX_SUFFIXES} .F .f .r .y .l .s .S .cl .p .h .sh .m4
 
@@ -17,78 +17,78 @@ PATH=/usr/sbin:/usr/bin:/usr/ucb:/opt/gnu/bin:/usr/ccs/bin
 
 # no -X
 LD_X=
-LD_x=		-x
-LD_r=		-r
-AR=		ar
-ARFLAGS=	rl
-RANLIB=		ranlib
-
-AS=		as
-AS_STDIN=	-
+LD_x ?=		-x
+LD_r ?=		-r
+AR ?=		ar
+ARFLAGS ?=	rl
+RANLIB ?=		ranlib
+
+AS ?=		as
+AS_STDIN ?=	-
 AFLAGS=
-COMPILE.s=	${AS} ${AFLAGS}
-LINK.s=		${CC} ${AFLAGS} ${LDFLAGS}
-COMPILE.S=	${CC} ${AFLAGS} ${CPPFLAGS} -c
-LINK.S=		${CC} ${AFLAGS} ${CPPFLAGS} ${LDFLAGS}
+COMPILE.s ?=	${AS} ${AFLAGS}
+LINK.s ?=		${CC} ${AFLAGS} ${LDFLAGS}
+COMPILE.S ?=	${CC} ${AFLAGS} ${CPPFLAGS} -c
+LINK.S ?=		${CC} ${AFLAGS} ${CPPFLAGS} ${LDFLAGS}
 .if exists(/opt/gnu/bin/gcc) || exists(/usr/local/bin/gcc)
-CC?=		gcc 
+CC ?=		gcc 
 .else
-CC?=             cc -std
+CC ?=             cc -std
 .endif
 .if (${CC:T} == "gcc")
-DBG=		-O -g
-STATIC=		-static
-DBG=         -g
-STATIC=         -non_shared
+DBG ?=		-O -g
+STATIC ?=		-static
+DBG ?=         -g
+STATIC ?=         -non_shared
 .endif
 
-CFLAGS=		${DBG}
-COMPILE.c=	${CC} ${CFLAGS} ${CPPFLAGS} -c
-LINK.c=		${CC} ${CFLAGS} ${CPPFLAGS} ${LDFLAGS}
+CFLAGS ?=		${DBG}
+COMPILE.c ?=	${CC} ${CFLAGS} ${CPPFLAGS} -c
+LINK.c ?=		${CC} ${CFLAGS} ${CPPFLAGS} ${LDFLAGS}
 
-CXX=		g++
-CXXFLAGS=	${CFLAGS}
-COMPILE.cc=	${CXX} ${CXXFLAGS} ${CPPFLAGS} -c
-LINK.cc=	${CXX} ${CXXFLAGS} ${CPPFLAGS} ${LDFLAGS}
+CXX ?=		g++
+CXXFLAGS ?=	${CFLAGS}
+COMPILE.cc ?=	${CXX} ${CXXFLAGS} ${CPPFLAGS} -c
+LINK.cc ?=	${CXX} ${CXXFLAGS} ${CPPFLAGS} ${LDFLAGS}
 
-CPP=		/usr/ccs/lib/cpp
+CPP ?=		/usr/ccs/lib/cpp
 .if defined(DESTDIR)
 CPPFLAGS+=	-nostdinc -idirafter ${DESTDIR}/usr/include
 .endif
 
-MK_DEP=	mkdeps.sh -N
-FC=		f77
-FFLAGS=		-O
+MK_DEP ?=	mkdeps.sh -N
+FC ?=		f77
+FFLAGS ?=		-O
 RFLAGS=
-COMPILE.f=	${FC} ${FFLAGS} -c
-LINK.f=		${FC} ${FFLAGS} ${LDFLAGS}
-COMPILE.F=	${FC} ${FFLAGS} ${CPPFLAGS} -c
-LINK.F=		${FC} ${FFLAGS} ${CPPFLAGS} ${LDFLAGS}
-COMPILE.r=	${FC} ${FFLAGS} ${RFLAGS} -c
-LINK.r=		${FC} ${FFLAGS} ${RFLAGS} ${LDFLAGS}
-
-LEX=		lex
+COMPILE.f ?=	${FC} ${FFLAGS} -c
+LINK.f ?=		${FC} ${FFLAGS} ${LDFLAGS}
+COMPILE.F ?=	${FC} ${FFLAGS} ${CPPFLAGS} -c
+LINK.F ?=		${FC} ${FFLAGS} ${CPPFLAGS} ${LDFLAGS}
+COMPILE.r ?=	${FC} ${FFLAGS} ${RFLAGS} -c
+LINK.r ?=		${FC} ${FFLAGS} ${RFLAGS} ${LDFLAGS}
+
+LEX ?=		lex
 LFLAGS=
-LEX.l=		${LEX} ${LFLAGS}
+LEX.l ?=		${LEX} ${LFLAGS}
 
-LD=		ld
+LD ?=		ld
 LDFLAGS=
 
-LINT=		lint
-LINTFLAGS=	-chapbx
+LINT ?=		lint
+LINTFLAGS ?=	-chapbx
 
-PC=		pc
+PC ?=		pc
 PFLAGS=
-COMPILE.p=	${PC} ${PFLAGS} ${CPPFLAGS} -c
-LINK.p=		${PC} ${PFLAGS} ${CPPFLAGS} ${LDFLAGS}
+COMPILE.p ?=	${PC} ${PFLAGS} ${CPPFLAGS} -c
+LINK.p ?=		${PC} ${PFLAGS} ${CPPFLAGS} ${LDFLAGS}
 
 .if exists(/usr/local/bin/bison) || exists(/opt/gnu/bin/bison)
-YACC=		bison -y
+YACC ?=		bison -y
 .else
-YACC=		yacc
+YACC ?=		yacc
 .endif
-YFLAGS=		-d
-YACC.y=		${YACC} ${YFLAGS}
+YFLAGS ?=		-d
+YACC.y ?=		${YACC} ${YFLAGS}
 
 # C
 .c:
diff --git a/mk/sys/OpenBSD.mk b/mk/sys/OpenBSD.mk
index 8b87ef3e85a4..d73bb0d82c9a 100644
--- a/mk/sys/OpenBSD.mk
+++ b/mk/sys/OpenBSD.mk
@@ -1,8 +1,8 @@
 #	$NetBSD: OpenBSD.sys.mk,v 1.1 2002/11/17 09:18:00 cjep Exp $
 #	@(#)sys.mk	8.2 (Berkeley) 3/21/94
 
-OS=		OpenBSD
-unix?=		We run ${OS}.
+OS ?=		OpenBSD
+unix ?=		We run ${OS}.
 
 .SUFFIXES: .out .a .ln .o .s .S .c ${CXX_SUFFIXES} .F .f .r .y .l .cl .p .h
 .SUFFIXES: .sh .m4
@@ -12,88 +12,88 @@ unix?=		We run ${OS}.
 # need to make sure this is set
 MACHINE_ARCH.${MACHINE} ?= ${MACHINE}
 .if empty(MACHINE_ARCH)
-MACHINE_ARCH = ${MACHINE_ARCH.${MACHINE}}
+MACHINE_ARCH  ?= ${MACHINE_ARCH.${MACHINE}}
 .endif
 
-AR?=		ar
-ARFLAGS?=	rl
-RANLIB?=	ranlib
+AR ?=		ar
+ARFLAGS ?=	rl
+RANLIB ?=	ranlib
 
-AS?=		as
-AFLAGS?=
+AS ?=		as
+AFLAGS ?=
 .if ${MACHINE_ARCH} == "sparc64" 
 AFLAGS+= -Wa,-Av9a
 .endif
-COMPILE.s?=	${CC} ${AFLAGS} -c
-LINK.s?=	${CC} ${AFLAGS} ${LDFLAGS}
-COMPILE.S?=	${CC} ${AFLAGS} ${CPPFLAGS} -c -traditional-cpp
-LINK.S?=	${CC} ${AFLAGS} ${CPPFLAGS} ${LDFLAGS}
+COMPILE.s ?=	${CC} ${AFLAGS} -c
+LINK.s ?=	${CC} ${AFLAGS} ${LDFLAGS}
+COMPILE.S ?=	${CC} ${AFLAGS} ${CPPFLAGS} -c -traditional-cpp
+LINK.S ?=	${CC} ${AFLAGS} ${CPPFLAGS} ${LDFLAGS}
 
-CC?=		cc
+CC ?=		cc
 .if ${MACHINE_ARCH} == "alpha" || \
     ${MACHINE_ARCH} == "i386" || \
     ${MACHINE_ARCH} == "m68k" || \
     ${MACHINE_ARCH} == "sparc" || \
     ${MACHINE_ARCH} == "vax"
-DBG?=	-O2
+DBG ?=	-O2
 .else
-DBG?=	-O
+DBG ?=	-O
 .endif
-CFLAGS?=	${DBG}
-COMPILE.c?=	${CC} ${CFLAGS} ${CPPFLAGS} -c
-LINK.c?=	${CC} ${CFLAGS} ${CPPFLAGS} ${LDFLAGS}
+CFLAGS ?=	${DBG}
+COMPILE.c ?=	${CC} ${CFLAGS} ${CPPFLAGS} -c
+LINK.c ?=	${CC} ${CFLAGS} ${CPPFLAGS} ${LDFLAGS}
 
-CXX?=		c++
-CXXFLAGS?=	${CFLAGS}
-COMPILE.cc?=	${CXX} ${CXXFLAGS} ${CPPFLAGS} -c
-LINK.cc?=	${CXX} ${CXXFLAGS} ${CPPFLAGS} ${LDFLAGS}
+CXX ?=		c++
+CXXFLAGS ?=	${CFLAGS}
+COMPILE.cc ?=	${CXX} ${CXXFLAGS} ${CPPFLAGS} -c
+LINK.cc ?=	${CXX} ${CXXFLAGS} ${CPPFLAGS} ${LDFLAGS}
 
-OBJC?=		${CC}
-OBJCFLAGS?=	${CFLAGS}
-COMPILE.m?=	${OBJC} ${OBJCFLAGS} ${CPPFLAGS} -c
-LINK.m?=	${OBJC} ${OBJCFLAGS} ${CPPFLAGS} ${LDFLAGS}
+OBJC ?=		${CC}
+OBJCFLAGS ?=	${CFLAGS}
+COMPILE.m ?=	${OBJC} ${OBJCFLAGS} ${CPPFLAGS} -c
+LINK.m ?=	${OBJC} ${OBJCFLAGS} ${CPPFLAGS} ${LDFLAGS}
 
-CPP?=		cpp
-CPPFLAGS?=	
+CPP ?=		cpp
+CPPFLAGS ?=	
 
-FC?=		f77
-FFLAGS?=	-O
-RFLAGS?=
-COMPILE.f?=	${FC} ${FFLAGS} -c
-LINK.f?=	${FC} ${FFLAGS} ${LDFLAGS}
-COMPILE.F?=	${FC} ${FFLAGS} ${CPPFLAGS} -c
-LINK.F?=	${FC} ${FFLAGS} ${CPPFLAGS} ${LDFLAGS}
-COMPILE.r?=	${FC} ${FFLAGS} ${RFLAGS} -c
-LINK.r?=	${FC} ${FFLAGS} ${RFLAGS} ${LDFLAGS}
+FC ?=		f77
+FFLAGS ?=	-O
+RFLAGS ?=
+COMPILE.f ?=	${FC} ${FFLAGS} -c
+LINK.f ?=	${FC} ${FFLAGS} ${LDFLAGS}
+COMPILE.F ?=	${FC} ${FFLAGS} ${CPPFLAGS} -c
+LINK.F ?=	${FC} ${FFLAGS} ${CPPFLAGS} ${LDFLAGS}
+COMPILE.r ?=	${FC} ${FFLAGS} ${RFLAGS} -c
+LINK.r ?=	${FC} ${FFLAGS} ${RFLAGS} ${LDFLAGS}
 
-INSTALL?=	install
+INSTALL ?=	install
 
-LEX?=		lex
-LFLAGS?=
-LEX.l?=		${LEX} ${LFLAGS}
+LEX ?=		lex
+LFLAGS ?=
+LEX.l ?=		${LEX} ${LFLAGS}
 
-LD?=		ld
-LDFLAGS?=
+LD ?=		ld
+LDFLAGS ?=
 
-LINT?=		lint
-LINTFLAGS?=	-chapbxzF
+LINT ?=		lint
+LINTFLAGS ?=	-chapbxzF
 
-LORDER?=	lorder
+LORDER ?=	lorder
 
-NM?=		nm
+NM ?=		nm
 
-PC?=		pc
-PFLAGS?=
-COMPILE.p?=	${PC} ${PFLAGS} ${CPPFLAGS} -c
-LINK.p?=	${PC} ${PFLAGS} ${CPPFLAGS} ${LDFLAGS}
+PC ?=		pc
+PFLAGS ?=
+COMPILE.p ?=	${PC} ${PFLAGS} ${CPPFLAGS} -c
+LINK.p ?=	${PC} ${PFLAGS} ${CPPFLAGS} ${LDFLAGS}
 
-SIZE?=		size
+SIZE ?=		size
 
-TSORT?= 	tsort -q
+TSORT ?= 	tsort -q
 
-YACC?=		yacc
-YFLAGS?=
-YACC.y?=	${YACC} ${YFLAGS}
+YACC ?=		yacc
+YFLAGS ?=
+YACC.y ?=	${YACC} ${YFLAGS}
 
 # C
 .c:
diff --git a/mk/sys/SunOS.mk b/mk/sys/SunOS.mk
index 71c985204fc6..e79cd3a7dbd4 100644
--- a/mk/sys/SunOS.mk
+++ b/mk/sys/SunOS.mk
@@ -1,19 +1,19 @@
-#	$Id: SunOS.mk,v 1.9 2020/04/17 21:08:17 sjg Exp $
+#	$Id: SunOS.mk,v 1.11 2020/06/29 14:34:42 sjg Exp $
 
 .if ${.PARSEFILE} == "sys.mk"
 .include <host-target.mk>
 
-OS?=		SunOS.${HOST_OSMAJOR}
-unix?=		We run ${OS}.
+OS ?=		SunOS.${HOST_OSMAJOR}
+unix ?=		We run ${OS}.
 .endif
 
 .if ${HOST_OSMAJOR} > 4
-ROOT_GROUP=	root
+ROOT_GROUP ?=	root
 
-SHLIB_FULLVERSION = ${SHLIB_MAJOR}
+SHLIB_FULLVERSION  ?= ${SHLIB_MAJOR}
 
 # suppress the dependency
-LIBCRT0= /dev/null
+LIBCRT0 ?= /dev/null
 
 .ifndef CC
 # the PATH below may find an ancient gcc
@@ -22,21 +22,21 @@ CC := ${gcc:L:${M_whence}}
 .endif
 
 # the stuff in /usr/xpg4/bin is usually more sane.
-PATH=/usr/xpg4/bin:/usr/sbin:/usr/bin:/usr/ucb:/usr/sfw/bin:/opt/gnu/bin:/usr/ccs/bin:/usr/local/bin
+PATH ?=/usr/xpg4/bin:/usr/sbin:/usr/bin:/usr/ucb:/usr/sfw/bin:/opt/gnu/bin:/usr/ccs/bin:/usr/local/bin
 .export PATH
 
-DSHLIBEXT = .so
-HOST_LIBDIRS = /usr/lib /lib /usr/sfw/lib
+DSHLIBEXT  ?= .so
+HOST_LIBDIRS  ?= /usr/lib /lib /usr/sfw/lib
 
 # no -X
 LD_X=
 LD_x=
-RANLIB=		:
-CPP=		/usr/ccs/lib/cpp
+RANLIB ?=		:
+CPP ?=		/usr/ccs/lib/cpp
 .else
-ROOT_GROUP=	wheel
-RANLIB=		ranlib
-CPP=		cpp
+ROOT_GROUP ?=	wheel
+RANLIB ?=		ranlib
+CPP ?=		cpp
 .endif
 
 # the rest is common
@@ -45,71 +45,71 @@ CPP=		cpp
 
 .LIBS:		.a
 
-AR=		ar
-ARFLAGS=	rl
+AR ?=		ar
+ARFLAGS ?=	rl
 
-AS=		as
-AS_STDIN=	-
+AS ?=		as
+AS_STDIN ?=	-
 AFLAGS=
-COMPILE.s=	${AS} ${AFLAGS}
-LINK.s=		${CC} ${AFLAGS} ${LDFLAGS}
-COMPILE.S=	${CC} ${AFLAGS} ${CPPFLAGS} -c
-LINK.S=		${CC} ${AFLAGS} ${CPPFLAGS} ${LDFLAGS}
+COMPILE.s ?=	${AS} ${AFLAGS}
+LINK.s ?=		${CC} ${AFLAGS} ${LDFLAGS}
+COMPILE.S ?=	${CC} ${AFLAGS} ${CPPFLAGS} -c
+LINK.S ?=		${CC} ${AFLAGS} ${CPPFLAGS} ${LDFLAGS}
 .if exists(/opt/gnu/bin/gcc) || exists(/usr/local/bin/gcc)
 CC ?=		gcc -pipe
-DBG=		-O -g
-STATIC=		-static
+DBG ?=		-O -g
+STATIC ?=		-static
 .else
 CC ?=             cc
-DBG=         -g
-STATIC=         -Bstatic
+DBG ?=         -g
+STATIC ?=         -Bstatic
 .endif
-CFLAGS=		${DBG}
-COMPILE.c=	${CC} ${CFLAGS} ${CPPFLAGS} -c
-LINK.c=		${CC} ${CFLAGS} ${CPPFLAGS} ${LDFLAGS}
+CFLAGS ?=		${DBG}
+COMPILE.c ?=	${CC} ${CFLAGS} ${CPPFLAGS} -c
+LINK.c ?=		${CC} ${CFLAGS} ${CPPFLAGS} ${LDFLAGS}
 
-CXX=		g++
-CXXFLAGS=	${CFLAGS}
-COMPILE.cc=	${CXX} ${CXXFLAGS} ${CPPFLAGS} -c
-LINK.cc=	${CXX} ${CXXFLAGS} ${CPPFLAGS} ${LDFLAGS}
+CXX ?=		g++
+CXXFLAGS ?=	${CFLAGS}
+COMPILE.cc ?=	${CXX} ${CXXFLAGS} ${CPPFLAGS} -c
+LINK.cc ?=	${CXX} ${CXXFLAGS} ${CPPFLAGS} ${LDFLAGS}
 
 .if defined(DESTDIR)
 CPPFLAGS+=	-nostdinc -idirafter ${DESTDIR}/usr/include
 .endif
 
-MK_DEP=	mkdeps.sh -N
-FC=		f77
-FFLAGS=		-O
+MK_DEP ?=	mkdeps.sh -N
+FC ?=		f77
+FFLAGS ?=		-O
 RFLAGS=
-COMPILE.f=	${FC} ${FFLAGS} -c
-LINK.f=		${FC} ${FFLAGS} ${LDFLAGS}
-COMPILE.F=	${FC} ${FFLAGS} ${CPPFLAGS} -c
-LINK.F=		${FC} ${FFLAGS} ${CPPFLAGS} ${LDFLAGS}
-COMPILE.r=	${FC} ${FFLAGS} ${RFLAGS} -c
-LINK.r=		${FC} ${FFLAGS} ${RFLAGS} ${LDFLAGS}
-
-LEX=		lex
+COMPILE.f ?=	${FC} ${FFLAGS} -c
+LINK.f ?=		${FC} ${FFLAGS} ${LDFLAGS}
+COMPILE.F ?=	${FC} ${FFLAGS} ${CPPFLAGS} -c
+LINK.F ?=		${FC} ${FFLAGS} ${CPPFLAGS} ${LDFLAGS}
+COMPILE.r ?=	${FC} ${FFLAGS} ${RFLAGS} -c
+LINK.r ?=		${FC} ${FFLAGS} ${RFLAGS} ${LDFLAGS}
+
+LEX ?=		lex
 LFLAGS=
-LEX.l=		${LEX} ${LFLAGS}
+LEX.l ?=		${LEX} ${LFLAGS}
 
-LD=		ld
+LD ?=		ld
 LDFLAGS=
 
-LINT=		lint
-LINTFLAGS=	-chapbx
+LINT ?=		lint
+LINTFLAGS ?=	-chapbx
 
-PC=		pc
+PC ?=		pc
 PFLAGS=
-COMPILE.p=	${PC} ${PFLAGS} ${CPPFLAGS} -c
-LINK.p=		${PC} ${PFLAGS} ${CPPFLAGS} ${LDFLAGS}
+COMPILE.p ?=	${PC} ${PFLAGS} ${CPPFLAGS} -c
+LINK.p ?=		${PC} ${PFLAGS} ${CPPFLAGS} ${LDFLAGS}
 
 .if exists(/usr/local/bin/bison) || exists(/opt/gnu/bin/bison)
-YACC=		bison -y
+YACC ?=		bison -y
 .else
-YACC=		yacc
+YACC ?=		yacc
 .endif
-YFLAGS=		-d
-YACC.y=		${YACC} ${YFLAGS}
+YFLAGS ?=		-d
+YACC.y ?=		${YACC} ${YFLAGS}
 
 # C
 .c:
diff --git a/mk/sys/UnixWare.mk b/mk/sys/UnixWare.mk
index 3b1e531515df..888f0d90c0b4 100644
--- a/mk/sys/UnixWare.mk
+++ b/mk/sys/UnixWare.mk
@@ -1,16 +1,16 @@
-#	$Id: UnixWare.mk,v 1.4 2020/04/17 21:08:17 sjg Exp $
+#	$Id: UnixWare.mk,v 1.6 2020/06/29 14:34:42 sjg Exp $
 #	based on "Id: SunOS.5.sys.mk,v 1.6 2003/09/30 16:42:23 sjg Exp "
 #	$NetBSD: sys.mk,v 1.19.2.1 1994/07/26 19:58:31 cgd Exp $
 #	@(#)sys.mk	5.11 (Berkeley) 3/13/91
 
-OS?=		UnixWare
-unix?=		We run ${OS}.
-ROOT_GROUP=	root
+OS ?=		UnixWare
+unix ?=		We run ${OS}.
+ROOT_GROUP ?=	root
 
 # can't fine one anywhere, so just stop the dependency
-LIBCRT0= /dev/null
+LIBCRT0 ?= /dev/null
 
-PATH=/usr/sbin:/usr/bin:/usr/ccs/bin:/usr/ccs/lib:/usr/ucb:/usr/local/bin
+PATH ?=/usr/sbin:/usr/bin:/usr/ccs/bin:/usr/ccs/lib:/usr/ucb:/usr/local/bin
 
 .SUFFIXES: .out .a .ln .o .c ${CXX_SUFFIXES} .F .f .r .y .l .s .S .cl .p .h .sh .m4
 
@@ -19,119 +19,119 @@ PATH=/usr/sbin:/usr/bin:/usr/ccs/bin:/usr/ccs/lib:/usr/ucb:/usr/local/bin
 # no -X
 LD_X=
 LD_x=
-AR?=		ar
-ARFLAGS?=	rl
-RANLIB?=	:
-
-AS?=		as
-AS_STDIN?=	-
-AFLAGS?=
-COMPILE.s?=	${AS} ${AFLAGS}
-LINK.s?=	${CC} ${AFLAGS} ${LDFLAGS}
-COMPILE.S?=	${CC} ${AFLAGS} ${CPPFLAGS} -c
-LINK.S?=	${CC} ${AFLAGS} ${CPPFLAGS} ${LDFLAGS}
+AR ?=		ar
+ARFLAGS ?=	rl
+RANLIB ?=	:
+
+AS ?=		as
+AS_STDIN ?=	-
+AFLAGS ?=
+COMPILE.s ?=	${AS} ${AFLAGS}
+LINK.s ?=	${CC} ${AFLAGS} ${LDFLAGS}
+COMPILE.S ?=	${CC} ${AFLAGS} ${CPPFLAGS} -c
+LINK.S ?=	${CC} ${AFLAGS} ${CPPFLAGS} ${LDFLAGS}
 
 # at least gcc 2.95 on UnixWare has no internal macro to identify the system
 .if exists(/usr/local/bin/gcc)
-CC?=		gcc -pipe -DUNIXWARE
-DBG?=		-O -g
-STATIC?=	-static
+CC ?=		gcc -pipe -DUNIXWARE
+DBG ?=		-O -g
+STATIC ?=	-static
 .else
-CC?=		cc
-DBG?=		-g
-STATIC?=	-Bstatic # XXX: don't know about UDK compilers
+CC ?=		cc
+DBG ?=		-g
+STATIC ?=	-Bstatic # XXX: don't know about UDK compilers
 .endif
-CFLAGS?=	${DBG}
-COMPILE.c?=	${CC} ${CFLAGS} ${CPPFLAGS} -c
-LINK.c?=	${CC} ${CFLAGS} ${CPPFLAGS} ${LDFLAGS}
+CFLAGS ?=	${DBG}
+COMPILE.c ?=	${CC} ${CFLAGS} ${CPPFLAGS} -c
+LINK.c ?=	${CC} ${CFLAGS} ${CPPFLAGS} ${LDFLAGS}
 
 .if exists(/usr/local/bin/g++)
-CXX?=		g++ -DUNIXWARE
+CXX ?=		g++ -DUNIXWARE
 .else
-CXX?=		c++ # XXX: don't know about UDK compilers
+CXX ?=		c++ # XXX: don't know about UDK compilers
 .endif
-CXXFLAGS?=	${CFLAGS}
-COMPILE.cc?=	${CXX} ${CXXFLAGS} ${CPPFLAGS} -c
-LINK.cc?=	${CXX} ${CXXFLAGS} ${CPPFLAGS} ${LDFLAGS}
+CXXFLAGS ?=	${CFLAGS}
+COMPILE.cc ?=	${CXX} ${CXXFLAGS} ${CPPFLAGS} -c
+LINK.cc ?=	${CXX} ${CXXFLAGS} ${CPPFLAGS} ${LDFLAGS}
 
-CPP?=		/usr/ccs/lib/cpp
+CPP ?=		/usr/ccs/lib/cpp
 .if defined(DESTDIR)
 CPPFLAGS+=	-nostdinc -idirafter ${DESTDIR}/usr/include
 .endif
 
-MK_DEP?=	mkdeps.sh -N
+MK_DEP ?=	mkdeps.sh -N
 .if exists(/usr/local/bin/g77)
-FC?=		g77
+FC ?=		g77
 .else
-FC?=		f77 # XXX: don't know about UDK compilers
+FC ?=		f77 # XXX: don't know about UDK compilers
 .endif
-FFLAGS?=	-O
-RFLAGS?=
-COMPILE.f?=	${FC} ${FFLAGS} -c
-LINK.f?=	${FC} ${FFLAGS} ${LDFLAGS}
-COMPILE.F?=	${FC} ${FFLAGS} ${CPPFLAGS} -c
-LINK.F?=	${FC} ${FFLAGS} ${CPPFLAGS} ${LDFLAGS}
-COMPILE.r?=	${FC} ${FFLAGS} ${RFLAGS} -c
-LINK.r?=	${FC} ${FFLAGS} ${RFLAGS} ${LDFLAGS}
-
-INSTALL?=	/usr/ucb/install # BSD install
-
-LEX?=		lex
-LFLAGS?=
-LEX.l?=		${LEX} ${LFLAGS}
-
-LD?=		ld
-LDFLAGS?=
-
-LIBC?=		${DESTDIR}/usr/ccs/lib/libc.a
-LIBCOMPAT?=
-LIBCRYPT?=	${DESTDIR}/usr/lib/libcrypt.a
-LIBCURSES?=	${DESTDIR}/usr/ccs/lib/libcurses.a
-LIBDBM?=
-LIBDES?=
-LIBEDIT?=
-LIBGCC?=
-LIBKDB?=
-LIBKRB?=
-LIBKVM?=
-LIBL?=		${DESTDIR}/usr/ccs/lib/libl.a
-LIBM?=		${DESTDIR}/usr/ccs/lib/libm.a
-LIBMP?=
-LIBPC?=
-LIBPCAP?=
-LIBPLOT?=
-LIBRESOLV?=
-LIBRPCSVC?=	${DESTDIR}/usr/lib/librpcsvc.a
-LIBSKEY?=	${DESTDIR}/usr/lib/libskey.a
-LIBTERMCAP?=	${DESTDIR}/usr/ccs/lib/libtermcap.a
-LIBUTIL?=
-LIBWRAP?=
-LIBY?=		${DESTDIR}/usr/ccs/lib/liby.a
-LIBZ?=
-
-LINT?=		lint
-LINTFLAGS?=	-pF
-
-LORDER?=	lorder
-
-NM?=		nm
-
-PC?=		pc # XXX: UDK probably does not have pc
-PFLAGS?=
-COMPILE.p?=	${PC} ${PFLAGS} ${CPPFLAGS} -c
-LINK.p?=	${PC} ${PFLAGS} ${CPPFLAGS} ${LDFLAGS}
-
-SIZE?=		size
-
-TSORT?=		tsort
+FFLAGS ?=	-O
+RFLAGS ?=
+COMPILE.f ?=	${FC} ${FFLAGS} -c
+LINK.f ?=	${FC} ${FFLAGS} ${LDFLAGS}
+COMPILE.F ?=	${FC} ${FFLAGS} ${CPPFLAGS} -c
+LINK.F ?=	${FC} ${FFLAGS} ${CPPFLAGS} ${LDFLAGS}
+COMPILE.r ?=	${FC} ${FFLAGS} ${RFLAGS} -c
+LINK.r ?=	${FC} ${FFLAGS} ${RFLAGS} ${LDFLAGS}
+
+INSTALL ?=	/usr/ucb/install # BSD install
+
+LEX ?=		lex
+LFLAGS ?=
+LEX.l ?=		${LEX} ${LFLAGS}
+
+LD ?=		ld
+LDFLAGS ?=
+
+LIBC ?=		${DESTDIR}/usr/ccs/lib/libc.a
+LIBCOMPAT ?=
+LIBCRYPT ?=	${DESTDIR}/usr/lib/libcrypt.a
+LIBCURSES ?=	${DESTDIR}/usr/ccs/lib/libcurses.a
+LIBDBM ?=
+LIBDES ?=
+LIBEDIT ?=
+LIBGCC ?=
+LIBKDB ?=
+LIBKRB ?=
+LIBKVM ?=
+LIBL ?=		${DESTDIR}/usr/ccs/lib/libl.a
+LIBM ?=		${DESTDIR}/usr/ccs/lib/libm.a
+LIBMP ?=
+LIBPC ?=
+LIBPCAP ?=
+LIBPLOT ?=
+LIBRESOLV ?=
+LIBRPCSVC ?=	${DESTDIR}/usr/lib/librpcsvc.a
+LIBSKEY ?=	${DESTDIR}/usr/lib/libskey.a
+LIBTERMCAP ?=	${DESTDIR}/usr/ccs/lib/libtermcap.a
+LIBUTIL ?=
+LIBWRAP ?=
+LIBY ?=		${DESTDIR}/usr/ccs/lib/liby.a
+LIBZ ?=
+
+LINT ?=		lint
+LINTFLAGS ?=	-pF
+
+LORDER ?=	lorder
+
+NM ?=		nm
+
+PC ?=		pc # XXX: UDK probably does not have pc
+PFLAGS ?=
+COMPILE.p ?=	${PC} ${PFLAGS} ${CPPFLAGS} -c
+LINK.p ?=	${PC} ${PFLAGS} ${CPPFLAGS} ${LDFLAGS}
+
+SIZE ?=		size
+
+TSORT ?=		tsort
 
 .if exists(/usr/local/bin/bison)
-YACC?=		bison -y
+YACC ?=		bison -y
 .else
-YACC?=		yacc
+YACC ?=		yacc
 .endif
-YFLAGS?=	-d
-YACC.y?=	${YACC} ${YFLAGS}
+YFLAGS ?=	-d
+YACC.y ?=	${YACC} ${YFLAGS}
 
 # C
 .c:
diff --git a/str.c b/str.c
index d3d7994a0868..bc0108a84d2c 100644
--- a/str.c
+++ b/str.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: str.c,v 1.42 2020/05/06 02:30:10 christos Exp $	*/
+/*	$NetBSD: str.c,v 1.48 2020/06/15 14:46:28 rillig Exp $	*/
 
 /*-
  * Copyright (c) 1988, 1989, 1990, 1993
@@ -69,14 +69,14 @@
  */
 
 #ifndef MAKE_NATIVE
-static char rcsid[] = "$NetBSD: str.c,v 1.42 2020/05/06 02:30:10 christos Exp $";
+static char rcsid[] = "$NetBSD: str.c,v 1.48 2020/06/15 14:46:28 rillig Exp $";
 #else
 #include <sys/cdefs.h>
 #ifndef lint
 #if 0
 static char     sccsid[] = "@(#)str.c	5.8 (Berkeley) 6/1/90";
 #else
-__RCSID("$NetBSD: str.c,v 1.42 2020/05/06 02:30:10 christos Exp $");
+__RCSID("$NetBSD: str.c,v 1.48 2020/06/15 14:46:28 rillig Exp $");
 #endif
 #endif				/* not lint */
 #endif
@@ -119,7 +119,7 @@ str_concat(const char *s1, const char *s2, int flags)
 	/* copy second string plus EOS into place */
 	memcpy(result + len1, s2, len2 + 1);
 
-	return(result);
+	return result;
 }
 
 /*-
@@ -304,7 +304,7 @@ Str_FindSubstring(const char *string, const char *substring)
 	 * substring.
 	 */
 
-	for (b = substring; *string != 0; string += 1) {
+	for (b = substring; *string != 0; string++) {
 		if (*string != *b)
 			continue;
 		a = string;
@@ -344,9 +344,9 @@ Str_Match(const char *string, const char *pattern)
 		 * pattern but not at the end of the string, we failed.
 		 */
 		if (*pattern == 0)
-			return(!*string);
+			return !*string;
 		if (*string == 0 && *pattern != '*')
-			return(0);
+			return 0;
 		/*
 		 * Check for a "*" as the next pattern character.  It matches
 		 * any substring.  We handle this by calling ourselves
@@ -354,15 +354,17 @@ Str_Match(const char *string, const char *pattern)
 		 * match or we reach the end of the string.
 		 */
 		if (*pattern == '*') {
-			pattern += 1;
+			pattern++;
+			while (*pattern == '*')
+				pattern++;
 			if (*pattern == 0)
-				return(1);
+				return 1;
 			while (*string != 0) {
 				if (Str_Match(string, pattern))
-					return(1);
+					return 1;
 				++string;
 			}
-			return(0);
+			return 0;
 		}
 		/*
 		 * Check for a "?" as the next pattern character.  It matches
@@ -388,14 +390,14 @@ Str_Match(const char *string, const char *pattern)
 				if ((*pattern == ']') || (*pattern == 0)) {
 					if (nomatch)
 						break;
-					return(0);
+					return 0;
 				}
 				if (*pattern == *string)
 					break;
 				if (pattern[1] == '-') {
 					c2 = pattern[2];
 					if (c2 == 0)
-						return(nomatch);
+						return nomatch;
 					if ((*pattern <= *string) &&
 					    (c2 >= *string))
 						break;
@@ -415,20 +417,20 @@ Str_Match(const char *string, const char *pattern)
 			goto thisCharOK;
 		}
 		/*
-		 * If the next pattern character is '/', just strip off the
-		 * '/' so we do exact matching on the character that follows.
+		 * If the next pattern character is a backslash, just strip it
+		 * off so we do exact matching on the character that follows.
 		 */
 		if (*pattern == '\\') {
 			++pattern;
 			if (*pattern == 0)
-				return(0);
+				return 0;
 		}
 		/*
 		 * There's no special character.  Just make sure that the
 		 * next characters of each string match.
 		 */
 		if (*pattern != *string)
-			return(0);
+			return 0;
 thisCharOK:	++pattern;
 		++string;
 	}
diff --git a/unit-tests/Makefile b/unit-tests/Makefile
index 5cf0212ce596..5c429c9648b9 100644
--- a/unit-tests/Makefile
+++ b/unit-tests/Makefile
@@ -1,6 +1,6 @@
-# $Id: Makefile,v 1.54 2020/05/17 17:26:14 sjg Exp $
+# $Id: Makefile,v 1.55 2020/06/29 14:47:56 sjg Exp $
 #
-# $NetBSD: Makefile,v 1.58 2020/05/17 12:36:26 rillig Exp $
+# $NetBSD: Makefile,v 1.59 2020/06/28 09:42:40 rillig Exp $
 #
 # Unit tests for make(1)
 # The main targets are:
@@ -27,6 +27,7 @@ UNIT_TESTS:= ${.PARSEDIR}
 TESTNAMES= \
 	comment \
 	cond-late \
+	cond-short \
 	cond1 \
 	cond2 \
 	dollar \
diff --git a/unit-tests/cond-short.exp b/unit-tests/cond-short.exp
new file mode 100644
index 000000000000..d8e3861d0c61
--- /dev/null
+++ b/unit-tests/cond-short.exp
@@ -0,0 +1,7 @@
+expected and
+expected and exists
+expected and empty
+expected or
+expected or exists
+expected or empty
+exit status 0
diff --git a/unit-tests/cond-short.mk b/unit-tests/cond-short.mk
new file mode 100644
index 000000000000..45bd45bfe3ba
--- /dev/null
+++ b/unit-tests/cond-short.mk
@@ -0,0 +1,62 @@
+# $NetBSD: cond-short.mk,v 1.2 2020/06/28 11:06:26 rillig Exp $
+#
+# Demonstrates that in conditions, the right-hand side of an && or ||
+# is only evaluated if it can actually influence the result.
+#
+# Between 2015-10-11 and 2020-06-28, the right-hand side of an && or ||
+# operator was always evaluated, which was wrong.
+#
+
+# The && operator.
+
+.if 0 && ${echo "unexpected and" 1>&2 :L:sh}
+.endif
+
+.if 1 && ${echo "expected and" 1>&2 :L:sh}
+.endif
+
+.if 0 && exists(nonexistent${echo "unexpected and exists" 1>&2 :L:sh})
+.endif
+
+.if 1 && exists(nonexistent${echo "expected and exists" 1>&2 :L:sh})
+.endif
+
+.if 0 && empty(${echo "unexpected and empty" 1>&2 :L:sh})
+.endif
+
+.if 1 && empty(${echo "expected and empty" 1>&2 :L:sh})
+.endif
+
+# The || operator.
+
+.if 1 || ${echo "unexpected or" 1>&2 :L:sh}
+.endif
+
+.if 0 || ${echo "expected or" 1>&2 :L:sh}
+.endif
+
+.if 1 || exists(nonexistent${echo "unexpected or exists" 1>&2 :L:sh})
+.endif
+
+.if 0 || exists(nonexistent${echo "expected or exists" 1>&2 :L:sh})
+.endif
+
+.if 1 || empty(${echo "unexpected or empty" 1>&2 :L:sh})
+.endif
+
+.if 0 || empty(${echo "expected or empty" 1>&2 :L:sh})
+.endif
+
+# Unreachable nested conditions are skipped completely as well.
+
+.if 0
+.  if ${echo "unexpected nested and" 1>&2 :L:sh}
+.  endif
+.endif
+
+.if 1
+.elif ${echo "unexpected nested or" 1>&2 :L:sh}
+.endif
+
+all:
+	@:;:
diff --git a/unit-tests/modmatch.mk b/unit-tests/modmatch.mk
index 45199287acdb..c631bbd3440f 100644
--- a/unit-tests/modmatch.mk
+++ b/unit-tests/modmatch.mk
@@ -15,7 +15,7 @@ res = no
 res = OK
 .endif
 
-all:	show-libs check-cclass
+all:	show-libs check-cclass slow
 
 show-libs:
 	@for x in $X; do ${.MAKE} -f ${MAKEFILE} show LIB=$$x; done
@@ -32,3 +32,8 @@ check-cclass:
 	@echo Upper=${LIST:M[A-Z]*}
 	@echo Lower=${LIST:M[^A-Z]*}
 	@echo nose=${LIST:M[^s]*[ex]}
+
+# Before 2020-06-13, this expression took quite a long time in Str_Match,
+# calling itself 601080390 times for 16 asterisks.
+slow: .PHONY
+	@:;: ${:U****************:M****************b:Q}
diff --git a/unit-tests/modorder.exp b/unit-tests/modorder.exp
index 411742738d63..8e0aad2e2027 100644
--- a/unit-tests/modorder.exp
+++ b/unit-tests/modorder.exp
@@ -1,5 +1,6 @@
 LIST      = one two three four five six seven eight nine ten
 LIST:O    = eight five four nine one seven six ten three two
+LIST:Or    = two three ten six seven one nine four five eight
 LIST:Ox   = Ok
 LIST:O:Ox = Ok
 LISTX     = Ok
diff --git a/unit-tests/modorder.mk b/unit-tests/modorder.mk
index 0f809391712f..89e64b43c57c 100644
--- a/unit-tests/modorder.mk
+++ b/unit-tests/modorder.mk
@@ -1,4 +1,4 @@
-# $NetBSD: modorder.mk,v 1.2 2020/01/07 22:42:14 rillig Exp $
+# $NetBSD: modorder.mk,v 1.3 2020/06/09 01:48:17 sjg Exp $
 
 LIST=		one two three four five six seven eight nine ten
 LISTX=		${LIST:Ox}
@@ -10,6 +10,7 @@ TEST_RESULT= && echo Ok || echo Failed
 all:
 	@echo "LIST      = ${LIST}"
 	@echo "LIST:O    = ${LIST:O}"
+	@echo "LIST:Or    = ${LIST:Or}"
 	# Note that 1 in every 10! trials two independently generated
 	# randomized orderings will be the same.  The test framework doesn't
 	# support checking probabilistic output, so we accept that each of the