Fix incremental builds involving non-root users with read-only source files.

Makefiles should not assume that source files can be overwritten.  This is the
common case for Perforce source trees.

This is a followup commit to r211243 in the same vein.

MFC after:	1 month
Sponsored by:	Spectra Logic
MFSpectraBSD:	r1036319 on 2014/01/29, r1046711 on 2014/03/06

bin/csh/Makefile

@@ -94,7 +94,7 @@ GENHDRS+= iconv.h
 SRCS+=	iconv_stub.c
 
 iconv.h: ${.CURDIR}/iconv_stub.h
-	cp ${.CURDIR}/iconv_stub.h ${.TARGET}
+	cp -f ${.CURDIR}/iconv_stub.h ${.TARGET}
 .endif
 .endif
 

etc/mail/Makefile

@@ -69,7 +69,7 @@ SENDMAIL_MC!=           hostname
 SENDMAIL_MC:=           ${SENDMAIL_MC}.mc
 
 ${SENDMAIL_MC}:
-	cp freebsd.mc ${SENDMAIL_MC}
+	cp -f freebsd.mc ${SENDMAIL_MC}
 .endif
 
 .ifndef SENDMAIL_SUBMIT_MC
@@ -77,7 +77,7 @@ SENDMAIL_SUBMIT_MC!=	hostname
 SENDMAIL_SUBMIT_MC:=	${SENDMAIL_SUBMIT_MC}.submit.mc
 
 ${SENDMAIL_SUBMIT_MC}:
-	cp freebsd.submit.mc ${SENDMAIL_SUBMIT_MC}
+	cp -f freebsd.submit.mc ${SENDMAIL_SUBMIT_MC}
 .endif
 
 INSTALL_CF=		${SENDMAIL_MC:R}.cf

lib/libc/Makefile

@@ -151,11 +151,11 @@ KSRCS=	bcmp.c ffs.c ffsl.c fls.c flsl.c mcount.c strcat.c strchr.c \
 libkern: libkern.gen libkern.${LIBC_ARCH}
 
 libkern.gen: ${KQSRCS} ${KSRCS}
-	cp -p ${LIBC_SRCTOP}/quad/quad.h ${.ALLSRC} ${DESTDIR}/sys/libkern
+	cp -fp ${LIBC_SRCTOP}/quad/quad.h ${.ALLSRC} ${DESTDIR}/sys/libkern
 
 libkern.${LIBC_ARCH}:: ${KMSRCS}
 .if defined(KMSRCS) && !empty(KMSRCS)
-	cp -p ${.ALLSRC} ${DESTDIR}/sys/libkern/${LIBC_ARCH}
+	cp -fp ${.ALLSRC} ${DESTDIR}/sys/libkern/${LIBC_ARCH}
 .endif
 
 .include <bsd.lib.mk>

usr.bin/grep/Makefile

@@ -11,7 +11,7 @@ PROG=	bsdgrep
 CLEANFILES+= bsdgrep.1
 
 bsdgrep.1: grep.1
-	cp ${.ALLSRC} ${.TARGET}
+	cp -f ${.ALLSRC} ${.TARGET}
 .endif
 SRCS=	file.c grep.c queue.c util.c
 

usr.sbin/mtree/Makefile

@@ -17,6 +17,6 @@ LDADD=	-lmd
 CLEANFILES+=	fmtree.8
 
 fmtree.8: mtree.8
-	cp ${.ALLSRC} ${.TARGET}
+	cp -f ${.ALLSRC} ${.TARGET}
 
 .include <bsd.prog.mk>