Merge bmake-20200517

Changes since 20181221 are mostly portability related
hence the large gap in versions imported.

There are however some bug fixes, and a rework of filemon handling.
In NetBSD make/filemon/filemon_ktrace.c allows use of fktrace
and elimination of filemon(4) which has not had the TLC it needs.

FreeBSD filemon(4) is in much better shape, so bmake/filemon/filemon_dev.c
allows use of that, with a bit less overhead than the ktrace model.

Summary of changes from ChangeLog

	o str.c: empty string does not match % pattern
	  plus unit-test changes
	o var.c: import handling of old sysV style modifier using '%'
	o str.c: refactor brk_string
	o meta.c: meta_oodate, CHECK_VALID_META is too aggressive for CMD
	  a blank command is perfectly valid.
	o meta.c: meta_oodate, check for corrupted meta file
	  earlier and more often.
	* meta.c: meta_compat_parent check for USE_FILEMON
	  patch from Soeren Tempel
	o meta.c: fix compat mode, need to call meta_job_output()
	o job.c: extra fds for meta mode not needed if using filemon_dev
	o meta.c: avoid passing NULL to filemon_*() when meta_needed()
	  returns FALSE.
	o filemon/filemon_{dev,ktrace}.c: allow selection of
	  filemon implementation.  filemon_dev.c uses the kernel module
	  while filemon_ktrace.c leverages the fktrace api available in
	  NetBSD.  filemon_ktrace.c can hopefully form the basis for
	  adding support for other tracing mechanisms such as strace on
	  Linux.
	o meta.c: when target is out-of-date per normal make rules
	  record value of .OODATE in meta file.
	o parse.c: don't pass NULL to realpath(3)
	  some versions cannot handle it.
	o parse.c: ParseDoDependency: free paths rather than assert

plus more unit-tests

1 files changed, 11 insertions, 7 deletions

diff --git a/contrib/bmake/mk/meta.sys.mk b/contrib/bmake/mk/meta.sys.mk
index 4dbdd7919baf..a561e04534f8 100644
--- a/contrib/bmake/mk/meta.sys.mk
+++ b/contrib/bmake/mk/meta.sys.mk
@@ -1,7 +1,7 @@
-# $Id: meta.sys.mk,v 1.32 2017/06/11 03:24:04 sjg Exp $
+# $Id: meta.sys.mk,v 1.36 2020/05/16 23:21:48 sjg Exp $
 
 #
-#	@(#) Copyright (c) 2010, Simon J. Gerraty
+#	@(#) Copyright (c) 2010-2020, Simon J. Gerraty
 #
 #	This file is provided in the hope that it will
 #	be of use.  There is absolutely NO WARRANTY.
@@ -22,7 +22,7 @@
 
 .-include <local.meta.sys.mk>
 
-# absoulte path to what we are reading.
+# absolute path to what we are reading.
 _PARSEDIR = ${.PARSEDIR:tA}
 
 .if !defined(SYS_MK_DIR)
@@ -61,13 +61,15 @@ META_MODE += silent=yes
 MACHINE = host
 .endif
 
-.if ${.MAKE.LEVEL} == 0
+.if !defined(MACHINE0)
 # it can be handy to know which MACHINE kicked off the build
 # for example, if using Makefild.depend for multiple machines,
 # allowing only MACHINE0 to update can keep things simple.
 MACHINE0 := ${MACHINE}
 .export MACHINE0
+.endif
 
+.if !defined(META2DEPS)
 .if defined(PYTHON) && exists(${PYTHON})
 # we prefer the python version of this - it is much faster
 META2DEPS ?= ${.PARSEDIR}/meta2deps.py
@@ -126,9 +128,11 @@ META_NOECHO= :
 # ignore mtime of shell
 # and mtime of makefiles does not matter in meta mode
 .MAKE.META.IGNORE_PATHS += \
-        ${MAKEFILE} \
-        ${SHELL} \
-        ${SYS_MK_DIR}
+	${MAKEFILE} \
+	${MAKE_SHELL} \
+	${SHELL} \
+	${SYS_MK_DIR} \
+
 
 .if ${UPDATE_DEPENDFILE:Uyes:tl} != "no"
 .if ${.MAKEFLAGS:Uno:M-k} != ""