introduce some common variables for use in GCC warning disables:

GCC_NO_FORMAT_TRUNCATION    -Wno-format-truncation (GCC 7/8)
GCC_NO_STRINGOP_TRUNCATION  -Wno-stringop-truncation (GCC 8)
GCC_NO_STRINGOP_OVERFLOW    -Wno-stringop-overflow (GCC 8)
GCC_NO_CAST_FUNCTION_TYPE   -Wno-cast-function-type (GCC 8)

use these to turn off warnings for most GCC-8 complaints.  many
of these are false positives, most of the real bugs are already
commited, or are yet to come.


we plan to introduce versions of (some?) of these that use the
"-Wno-error=" form, which still displays the warnings but does
not make it an error, and all of the above will be re-considered
as either being "fix me" (warning still displayed) or "warning
is wrong."

bin/pax/Makefile

@@ -1,4 +1,4 @@
-#	$NetBSD: Makefile,v 1.40 2019/08/15 21:05:16 uwe Exp $
+#	$NetBSD: Makefile,v 1.41 2019/10/13 07:28:04 mrg Exp $
 #       @(#)Makefile	8.1 (Berkeley) 5/31/93
 
 .include <bsd.own.mk>
@@ -50,4 +50,6 @@ LDADD+=	-lrmt
 DPADD+=	${LIBRMT}
 .endif
 
+COPTS.tar.c+=	${GCC_NO_STRINGOP_TRUNCATION}
+
 .include <bsd.prog.mk>

crypto/external/bsd/netpgp/bin/netpgpverify/Makefile

@@ -1,4 +1,4 @@
-#	$NetBSD: Makefile,v 1.17 2019/09/29 23:44:58 mrg Exp $
+#	$NetBSD: Makefile,v 1.18 2019/10/13 07:28:04 mrg Exp $
 
 PROG=netpgpverify
 BINDIR=		/usr/bin
@@ -32,6 +32,8 @@ EXTDIST=${.CURDIR}/../../dist
 COPTS+=	-Wno-error=implicit-fallthrough
 .endif
 
+COPTS.libverify.c+=	${GCC_NO_FORMAT_TRUNCATION}
+
 .include <bsd.prog.mk>
 
 t tst: ${PROG}

crypto/external/bsd/netpgp/lib/netpgp/Makefile

@@ -1,4 +1,4 @@
-# $NetBSD: Makefile,v 1.3 2018/02/04 03:19:52 christos Exp $
+# $NetBSD: Makefile,v 1.4 2019/10/13 07:28:05 mrg Exp $
 
 .include <bsd.own.mk>
 
@@ -26,4 +26,6 @@ LIBDPLIBS+=	crypto		${OPENSSL}/lib/libcrypto
 LIBDPLIBS+=	z		${NETBSDSRCDIR}/lib/libz
 LIBDPLIBS+=	bz2		${NETBSDSRCDIR}/lib/libbz2
 
+COPTS.crypto.c+=	${GCC_NO_STRINGOP_OVERFLOW}
+
 .include <bsd.lib.mk>

crypto/external/bsd/netpgp/lib/verify/Makefile

@@ -1,4 +1,4 @@
-# $NetBSD: Makefile,v 1.11 2019/09/29 23:44:58 mrg Exp $
+# $NetBSD: Makefile,v 1.12 2019/10/13 07:28:05 mrg Exp $
 
 LIB=netpgpverify
 SRCS+=b64.c
@@ -27,8 +27,7 @@ INCSDIR=/usr/include/netpgp
 
 .include <bsd.own.mk>
 
-.if defined(HAVE_GCC) && ${HAVE_GCC} >= 7 && ${ACTIVE_CC} == "gcc"
-COPTS+=	-Wno-error=implicit-fallthrough
-.endif
+COPTS+=			${${ACTIVE_CC} == "gcc":? -Wno-implicit-fallthrough :}
+COPTS.libverify.c+=	${GCC_NO_FORMAT_TRUNCATION}
 
 .include <bsd.lib.mk>

crypto/external/bsd/openssh/bin/ssh-agent/Makefile

@@ -1,8 +1,10 @@
-#	$NetBSD: Makefile,v 1.2 2010/11/21 19:19:22 adam Exp $
+#	$NetBSD: Makefile,v 1.3 2019/10/13 07:28:05 mrg Exp $
 
 BINDIR=/usr/bin
 
 PROG=	ssh-agent
 SRCS=	ssh-agent.c ssh-pkcs11-client.c
 
+COPTS.ssh-agent.c+=	${GCC_NO_FORMAT_TRUNCATION}
+
 .include <bsd.prog.mk>

crypto/external/bsd/openssh/bin/ssh-keygen/Makefile

@@ -1,4 +1,4 @@
-#	$NetBSD: Makefile,v 1.5 2019/10/12 18:32:21 christos Exp $
+#	$NetBSD: Makefile,v 1.6 2019/10/13 07:28:05 mrg Exp $
 
 BINDIR=	/usr/bin
 
@@ -7,4 +7,6 @@ SRCS=	ssh-keygen.c moduli.c sshsig.c
 
 COPTS.ssh-keygen.c=	-Wno-pointer-sign
 
+COPTS.ssh-keygen.c+=	${GCC_NO_FORMAT_TRUNCATION}
+
 .include <bsd.prog.mk>

crypto/external/bsd/openssh/bin/ssh/Makefile

@@ -1,4 +1,4 @@
-#	$NetBSD: Makefile,v 1.14 2018/04/06 18:58:59 christos Exp $
+#	$NetBSD: Makefile,v 1.15 2019/10/13 07:28:05 mrg Exp $
 
 .include <bsd.own.mk>
 
@@ -23,4 +23,6 @@ LDADD+=	-lgssapi -lheimntlm ${LIBKRB5_LDADD}
 DPADD+=	${LIBGSSAPI} ${LIBHEIMNTLM} ${LIBKRB5_DPADD}
 .endif
 
+COPTS.sshconnect.c+=	${GCC_NO_FORMAT_TRUNCATION}
+
 .include <bsd.prog.mk>

crypto/external/bsd/openssh/bin/sshd/Makefile

@@ -1,4 +1,4 @@
-#	$NetBSD: Makefile,v 1.18 2019/10/12 18:32:21 christos Exp $
+#	$NetBSD: Makefile,v 1.19 2019/10/13 07:28:05 mrg Exp $
 
 .include <bsd.own.mk>
 
@@ -58,8 +58,6 @@ LDADD+=	-lldap -lssl -llber
 DPADD+=	${LIBLDAP} ${LIBSSL} ${LIBLBER}
 .endif
 
-.include <bsd.prog.mk>
-
 LDADD+=	-lcrypt -lutil
 DPADD+=	${LIBCRYPT} ${LIBUTIL}
 
@@ -72,3 +70,8 @@ CPPFLAGS+=-DSMALL
 LDADD+=	-lblacklist
 DPADD+=	${LIBBLACKLIST}
 .endif
+
+COPTS.sshlogin.c+=	${GCC_NO_STRINGOP_TRUNCATION}
+COPTS.ldapauth.c+=	${GCC_NO_STRINGOP_TRUNCATION} ${GCC_NO_STRINGOP_OVERFLOW}
+
+.include <bsd.prog.mk>

crypto/external/bsd/openssh/lib/Makefile

@@ -1,4 +1,4 @@
-#	$NetBSD: Makefile,v 1.28 2019/10/12 18:32:22 christos Exp $
+#	$NetBSD: Makefile,v 1.29 2019/10/13 07:28:05 mrg Exp $
 
 .include <bsd.own.mk>
 
@@ -120,4 +120,7 @@ COPTS.poly1305.c+=	-O0
 COPTS.umac.c+=		-O0
 .endif
 
+COPTS.hostfile.c+=	${GCC_NO_FORMAT_TRUNCATION}
+COPTS.sshkey.c+=	${GCC_NO_FORMAT_TRUNCATION}
+
 .include <bsd.lib.mk>

external/bsd/am-utils/bin/amd/Makefile

@@ -1,4 +1,4 @@
-#	$NetBSD: Makefile,v 1.12 2017/05/21 15:28:38 riastradh Exp $
+#	$NetBSD: Makefile,v 1.13 2019/10/13 07:28:05 mrg Exp $
 
 .include "${.CURDIR}/../Makefile.inc"
 
@@ -73,5 +73,6 @@ build_version.h: get_args.c
 	echo '#define BUILD_HOST "'unknown'"' >> ${.TARGET}
 	echo '#define BUILD_DATE "'unknown'"' >> ${.TARGET}
 
+COPTS.sun_map.c+=	${GCC_NO_STRINGOP_TRUNCATION}
 
 .include <bsd.prog.mk>

external/bsd/fetch/lib/Makefile

@@ -1,4 +1,4 @@
-# $NetBSD: Makefile,v 1.14 2019/10/10 02:30:43 kre Exp $
+# $NetBSD: Makefile,v 1.15 2019/10/13 07:28:05 mrg Exp $
 
 LIB=		fetch
 SRCS=		fetch.c common.c ftp.c http.c file.c
@@ -36,8 +36,6 @@ httperr.h: ${LIBFETCHDIR}/http.errors ${LIBFETCHDIR}/errlist.sh
 CFLAGS+=	-Wno-macro-redefined # _REENTRANT redefined
 .endif
 
-.if defined(HAVE_GCC) && ${HAVE_GCC} >= 8 && ${ACTIVE_CC} == "gcc"
-COPTS.http.c += -Wno-error=stringop-truncation
-.endif
+COPTS.http.c+=	${GCC_NO_STRINGOP_TRUNCATION}
 
 .include <bsd.lib.mk>

external/bsd/flex/bin/Makefile

@@ -1,5 +1,5 @@
 #	from: @(#)Makefile	5.4 (Berkeley) 6/24/90
-#	$NetBSD: Makefile,v 1.14 2019/09/29 23:44:58 mrg Exp $
+#	$NetBSD: Makefile,v 1.15 2019/10/13 07:28:06 mrg Exp $
 #
 # By default, flex will be configured to generate 8-bit scanners only if the
 # -8 flag is given.  If you want it to always generate 8-bit scanners, add
@@ -78,4 +78,7 @@ COPTS.scan.c+=        -O1
 . endif
 .endif
 
+COPTS.filter.c+=	${GCC_NO_FORMAT_TRUNCATION}
+COPTS.misc.c+=		${GCC_NO_FORMAT_TRUNCATION}
+
 .include <bsd.prog.mk>

external/bsd/ipf/Makefile.inc

@@ -1,4 +1,4 @@
-#	$NetBSD: Makefile.inc,v 1.3 2017/01/11 12:19:43 joerg Exp $
+#	$NetBSD: Makefile.inc,v 1.4 2019/10/13 07:28:06 mrg Exp $
 
 WARNS?=	1	# XXX -Wcast-qual -Wshadow
 CWARNFLAGS.clang+=	-Wno-format -Wno-tautological-compare \
@@ -32,6 +32,8 @@ LDADD+=		-L${IPFOBJDIR} -lipf -lkvm
 
 CLEANFILES+=	y.tab.c y.tab.h
 
+COPTS+=	${GCC_NO_STRINGOP_TRUNCATION}
+
 .PATH:	${UDIST}	\
 	${UDIST}/lib	\
 	${UDIST}/tools	\

external/bsd/ipf/bin/ipftest/Makefile

@@ -1,4 +1,4 @@
-#	$NetBSD: Makefile,v 1.6 2019/09/29 23:44:58 mrg Exp $
+#	$NetBSD: Makefile,v 1.7 2019/10/13 07:28:06 mrg Exp $
 
 .include <bsd.own.mk>
 
@@ -109,4 +109,6 @@ COPTS.ipf_y.c+=	-O1
 . endif
 .endif
 
+COPTS.fil.c+=	${GCC_NO_STRINGOP_OVERFLOW}
+
 .include <bsd.prog.mk>

external/bsd/iscsi/lib/Makefile

@@ -1,4 +1,4 @@
-# $NetBSD: Makefile,v 1.4 2012/01/01 01:19:20 wrstuden Exp $
+# $NetBSD: Makefile,v 1.5 2019/10/13 07:28:06 mrg Exp $
 
 .include <bsd.own.mk>
 
@@ -23,4 +23,6 @@ ISCSIDIST=	${.CURDIR}/../dist
 
 LIBDPLIBS+=      pthread  ${.CURDIR}/../../../../lib/libpthread
 
+COPTS.target.c+=	${GCC_NO_FORMAT_TRUNCATION}
+
 .include <bsd.lib.mk>

external/bsd/libarchive/lib/libarchive/Makefile

@@ -1,4 +1,4 @@
-#	$NetBSD: Makefile,v 1.10 2019/07/24 14:07:17 joerg Exp $
+#	$NetBSD: Makefile,v 1.11 2019/10/13 07:28:06 mrg Exp $
 
 .include <bsd.init.mk>
 
@@ -455,4 +455,7 @@ COPTS.archive_read_support_format_7zip.c += -Wno-error=implicit-fallthrough
 COPTS.archive_read_support_format_mtree.c += -Wno-error=implicit-fallthrough
 .endif
 
+COPTS.target.c+=	${GCC_NO_STRINGOP_TRUNCATION}
+COPTS.archive_write_set_format_iso9660.c+=	${GCC_NO_STRINGOP_TRUNCATION}
+
 .include <bsd.lib.mk>

external/bsd/libpcap/lib/Makefile

@@ -1,4 +1,4 @@
-# $NetBSD: Makefile,v 1.25 2019/10/01 16:02:12 christos Exp $	
+# $NetBSD: Makefile,v 1.26 2019/10/13 07:28:06 mrg Exp $	
 
 USE_SHLIBDIR=yes
 .include <bsd.own.mk>
@@ -165,10 +165,9 @@ CLEANFILES+=	tokdefs.h scanner.h
 
 COPTS.bpf_image.c+=	-Wno-format-nonliteral
 
-.if defined(HAVE_GCC) && ${HAVE_GCC} >= 7 && ${ACTIVE_CC} == "gcc"
-COPTS.pcap.c+=		-Wno-error=format-truncation
-COPTS.gencode.c+=	-Wno-error=implicit-fallthrough
-.endif
+COPTS.gencode.c+=	${${ACTIVE_CC} == "gcc" && ${HAVE_GCC:U0} >= 7:? -Wno-error=implicit-fallthrough :}
+COPTS.pcap.c+=		${GCC_NO_FORMAT_TRUNCATION}
+COPTS.pcap-bpf.c+=	${GCC_NO_STRINGOP_TRUNCATION}
 
 CWARNFLAGS.clang+=	-Wno-format-extra-args \
 			-Wno-unneeded-internal-declaration

external/bsd/llvm/lib/libLLVMAnalysis/Makefile

@@ -1,4 +1,4 @@
-#	$NetBSD: Makefile,v 1.25 2018/07/17 18:55:27 joerg Exp $
+#	$NetBSD: Makefile,v 1.26 2019/10/13 07:28:06 mrg Exp $
 
 LIB=	LLVMAnalysis
 
@@ -99,4 +99,5 @@ SRCS+=	AliasAnalysis.cpp \
 .include <bsd.hostlib.mk>
 .else
 .include <bsd.lib.mk>
+COPTS.ValueTracking.cpp+=	${GCC_NO_STRINGOP_OVERFLOW}
 .endif

external/bsd/llvm/lib/libLLVMRuntimeDyld/Makefile

@@ -1,4 +1,4 @@
-#	$NetBSD: Makefile,v 1.10 2019/03/10 12:14:06 mrg Exp $
+#	$NetBSD: Makefile,v 1.11 2019/10/13 07:28:06 mrg Exp $
 
 LIB=	LLVMRuntimeDyld
 
@@ -21,4 +21,5 @@ SRCS+=	RuntimeDyldELFMips.cpp
 .include <bsd.hostlib.mk>
 .else
 .include <bsd.lib.mk>
+COPTS.RuntimeDyldChecker.cpp+=	${GCC_NO_STRINGOP_OVERFLOW}
 .endif

external/bsd/mdocml/bin/mandoc/Makefile

@@ -1,4 +1,4 @@
-# $NetBSD: Makefile,v 1.18 2019/03/11 17:59:28 christos Exp $
+# $NetBSD: Makefile,v 1.19 2019/10/13 07:28:06 mrg Exp $
 
 .include <bsd.own.mk>
 
@@ -46,4 +46,6 @@ SRCS+=		${SRCS.libmandoc} compat_strtonum.c compat_reallocarray.c
 
 COPTS.man_term.c+= -Wno-error=array-bounds
 
+COPTS.tbl_term.c+=	${GCC_NO_FORMAT_TRUNCATION}
+
 .include <bsd.prog.mk>

external/bsd/ntp/bin/ntpd/Makefile

@@ -1,4 +1,4 @@
-#	$NetBSD: Makefile,v 1.23 2019/10/04 09:47:27 mrg Exp $
+#	$NetBSD: Makefile,v 1.24 2019/10/13 07:28:07 mrg Exp $
 
 .include <bsd.own.mk>
 
@@ -93,5 +93,10 @@ COPTS.ntp_control.c+=  -Wno-error=maybe-uninitialized
 .endif
 
 COPTS.ntp_loopfilter.c+=	${${ACTIVE_CC} == "gcc" && ${HAVE_GCC:U0} == 8:? -Wno-error=restrict :}
+COPTS.ntp_loopfilter.c+=	${GCC_NO_FORMAT_TRUNCATION}
+COPTS.ntp_crypto.c+=		${GCC_NO_FORMAT_TRUNCATION}
+COPTS.refclock_parse.c+=	${GCC_NO_FORMAT_TRUNCATION}
+COPTS.refclock_leitch.c+=	${GCC_NO_FORMAT_TRUNCATION}
+COPTS.refclock_neoclock4x.c+=	${GCC_NO_FORMAT_TRUNCATION}
 
 .include <bsd.prog.mk>

external/bsd/ntp/bin/ntpq/Makefile

@@ -1,4 +1,4 @@
-#	$NetBSD: Makefile,v 1.7 2013/12/28 03:19:43 christos Exp $
+#	$NetBSD: Makefile,v 1.8 2019/10/13 07:28:07 mrg Exp $
 
 .include <bsd.own.mk>
 
@@ -21,4 +21,6 @@ CPPFLAGS+=-I${IDIST}/include -I${IDIST}/sntp/libopts
 
 .PATH: ${DIST}
 
+COPTS.ntpq.c+=	${GCC_NO_STRINGOP_TRUNCATION}
+
 .include <bsd.prog.mk>

external/bsd/ntp/bin/sntp/Makefile

@@ -1,4 +1,4 @@
-# $NetBSD: Makefile,v 1.6 2013/12/28 03:19:43 christos Exp $
+# $NetBSD: Makefile,v 1.7 2019/10/13 07:28:07 mrg Exp $
 
 USE_FORT?= yes	# network client/server
 
@@ -31,4 +31,6 @@ CPPFLAGS+= -DSAVENAME=\"/var/db/sntp.state\"
 LDADD+= -L${LIBISC} -liscntp -levent -lm
 DPADD+=	${LIBM} ${LIBEVENT}
 
+COPTS.utilities.c+=	${GCC_NO_FORMAT_TRUNCATION}
+
 .include <bsd.prog.mk>

external/bsd/ntp/lib/libntp/Makefile

@@ -1,4 +1,4 @@
-#	$NetBSD: Makefile,v 1.20 2018/02/02 01:02:40 mrg Exp $
+#	$NetBSD: Makefile,v 1.21 2019/10/13 07:28:07 mrg Exp $
 
 LIBISPRIVATE=yes
 
@@ -99,4 +99,6 @@ CPPFLAGS.ntp_calendar.c += -DMKREPRO_DATE=\"${MKREPRO_DATE:Q}\"
 CPPFLAGS.ntp_calendar.c += -DMKREPRO_TIME=\"${MKREPRO_TIME:Q}\"
 .endif
 
+COPTS.timetoa.c+=	${GCC_NO_FORMAT_TRUNCATION}
+
 .include <bsd.lib.mk>

external/bsd/pdisk/bin/Makefile

@@ -1,4 +1,4 @@
-#	$NetBSD: Makefile,v 1.3 2019/09/29 23:44:59 mrg Exp $	
+#	$NetBSD: Makefile,v 1.4 2019/10/13 07:28:07 mrg Exp $	
 
 .include <bsd.own.mk>
 WARNS=5
@@ -21,9 +21,12 @@ CPPFLAGS+=	-I${SRCDIR}
 CPPFLAGS+=	-D__unix__
 
 .if defined(HAVE_GCC) && ${HAVE_GCC} >= 7 && ${ACTIVE_CC} == "gcc"
-COPTS.file_media.c+=	-Wno-error=implicit-fallthrough
-COPTS.pathname.c+=	-Wno-error=implicit-fallthrough
-COPTS.pdisk.c+=		-Wno-error=implicit-fallthrough
+COPTS.file_media.c+=	-Wno-implicit-fallthrough
+COPTS.pathname.c+=	-Wno-implicit-fallthrough
+COPTS.pdisk.c+=		-Wno-implicit-fallthrough
 .endif
 
+COPTS.partition_map.c+=	${GCC_NO_STRINGOP_TRUNCATION}
+COPTS.pdisk.c+=		${GCC_NO_STRINGOP_TRUNCATION}
+
 .include <bsd.prog.mk>

external/bsd/ppp/usr.sbin/pppd/Makefile

@@ -1,4 +1,4 @@
-#	$NetBSD: Makefile,v 1.1 2013/11/28 22:33:43 christos Exp $
+#	$NetBSD: Makefile,v 1.2 2019/10/13 07:28:07 mrg Exp $
 
 .include "../Makefile.inc"
 
@@ -39,4 +39,6 @@ COPTS.${f}.c+=	-Wno-pointer-sign
 
 CWARNFLAGS.clang+=	-Wno-tautological-compare
 
+COPTS.session.c+=	${GCC_NO_STRINGOP_TRUNCATION}
+
 .include <bsd.prog.mk>

external/bsd/ppp/usr.sbin/pppstats/Makefile

@@ -1,4 +1,4 @@
-#	$NetBSD: Makefile,v 1.1 2013/11/28 22:33:43 christos Exp $
+#	$NetBSD: Makefile,v 1.2 2019/10/13 07:28:07 mrg Exp $
 
 .include "../Makefile.inc"
 
@@ -9,4 +9,6 @@ MAN=	pppstats.8
 LINKS=  ${BINDIR}/pppstats ${BINDIR}/slstats
 MLINKS=	pppstats.8 slstats.8
 
+COPTS.pppstats.c+=	${GCC_NO_STRINGOP_TRUNCATION}
+
 .include <bsd.prog.mk>