From 7afab8a67ee7f4114887bc3b024cc58f8c6dedf1 Mon Sep 17 00:00:00 2001
From: Mark Johnston <markj@FreeBSD.org>
Date: Fri, 18 Sep 2020 19:03:34 +0000
Subject: [PATCH] Install library symlinks atomically.

As we do for shared library binaries, pass -S to install(1) when
installing symlinks.  Doing so helps avoid transient failures when
libraries are being reinstalled, which seems to be the root cause of
spurious libgcc_s.so link failures during CI builds.

PR:		233769
Reviewed by:	emaste
MFC after:	1 week
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D26453
---
 share/mk/bsd.lib.mk | 20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

diff --git a/share/mk/bsd.lib.mk b/share/mk/bsd.lib.mk
index f1bc3bf836d7..9997bfa979df 100644
--- a/share/mk/bsd.lib.mk
+++ b/share/mk/bsd.lib.mk
@@ -403,6 +403,7 @@ SHLINSTALLFLAGS+= -fschg
 # that are only creating an image.
 .if !defined(NO_SAFE_LIBINSTALL) && !defined(NO_ROOT)
 SHLINSTALLFLAGS+= -S
+SHLINSTALLSYMLINKFLAGS+= -S
 .endif
 
 _INSTALLFLAGS:=	${INSTALLFLAGS}
@@ -410,6 +411,7 @@ _INSTALLFLAGS:=	${INSTALLFLAGS}
 _INSTALLFLAGS:=	${_INSTALLFLAGS${ie}}
 .endfor
 _SHLINSTALLFLAGS:=	${SHLINSTALLFLAGS}
+_SHLINSTALLSYMLINKFLAGS:= ${SHLINSTALLSYMLINKFLAGS}
 .for ie in ${INSTALLFLAGS_EDIT}
 _SHLINSTALLFLAGS:=	${_SHLINSTALLFLAGS${ie}}
 .endfor
@@ -444,29 +446,31 @@ _libinstall:
 	    ${_INSTALLFLAGS} ${SHLIB_LINK:R}.ld \
 	    ${DESTDIR}${_LIBDIR}/${SHLIB_LINK}
 .for _SHLIB_LINK_LINK in ${SHLIB_LDSCRIPT_LINKS}
-	${INSTALL_LIBSYMLINK} ${TAG_ARGS} ${SHLIB_LINK} ${DESTDIR}${_LIBDIR}/${_SHLIB_LINK_LINK}
+	${INSTALL_LIBSYMLINK} ${_SHLINSTALLSYMLINKFLAGS} ${TAG_ARGS} ${SHLIB_LINK} \
+	    ${DESTDIR}${_LIBDIR}/${_SHLIB_LINK_LINK}
 .endfor
 .else
 .if ${_SHLIBDIR} == ${_LIBDIR}
 .if ${SHLIB_LINK:Mlib*}
-	${INSTALL_RSYMLINK} ${TAG_ARGS:D${TAG_ARGS},dev} ${SHLIB_NAME} ${DESTDIR}${_LIBDIR}/${SHLIB_LINK}
+	${INSTALL_RSYMLINK} ${_SHLINSTALLSYMLINKFLAGS} ${TAG_ARGS:D${TAG_ARGS},dev} \
+	    ${SHLIB_NAME} ${DESTDIR}${_LIBDIR}/${SHLIB_LINK}
 .else
-	${INSTALL_RSYMLINK} ${TAG_ARGS} ${DESTDIR}${_SHLIBDIR}/${SHLIB_NAME} \
+	${INSTALL_RSYMLINK} ${_SHLINSTALLSYMLINKFLAGS} ${TAG_ARGS} ${DESTDIR}${_SHLIBDIR}/${SHLIB_NAME} \
 	    ${DESTDIR}${_LIBDIR}/${SHLIB_LINK}
 .endif
 .else
 .if ${SHLIB_LINK:Mlib*}
-	${INSTALL_RSYMLINK} ${TAG_ARGS:D${TAG_ARGS},dev} ${DESTDIR}${_SHLIBDIR}/${SHLIB_NAME} \
-	    ${DESTDIR}${_LIBDIR}/${SHLIB_LINK}
+	${INSTALL_RSYMLINK} ${_SHLINSTALLSYMLINKFLAGS} ${TAG_ARGS:D${TAG_ARGS},dev} \
+	    ${DESTDIR}${_SHLIBDIR}/${SHLIB_NAME} ${DESTDIR}${_LIBDIR}/${SHLIB_LINK}
 .else
-	${INSTALL_RSYMLINK} ${TAG_ARGS} ${DESTDIR}${_SHLIBDIR}/${SHLIB_NAME} \
-	    ${DESTDIR}${_LIBDIR}/${SHLIB_LINK}
+	${INSTALL_RSYMLINK} ${_SHLINSTALLSYMLINKFLAGS} ${TAG_ARGS} \
+	    ${DESTDIR}${_SHLIBDIR}/${SHLIB_NAME} ${DESTDIR}${_LIBDIR}/${SHLIB_LINK}
 .endif
 .if exists(${DESTDIR}${_LIBDIR}/${SHLIB_NAME})
 	-chflags noschg ${DESTDIR}${_LIBDIR}/${SHLIB_NAME}
 	rm -f ${DESTDIR}${_LIBDIR}/${SHLIB_NAME}
 .endif
-.endif
+.endif # _SHLIBDIR == _LIBDIR
 .endif # SHLIB_LDSCRIPT
 .endif # SHLIB_LINK
 .endif # SHIB_NAME