gentoo resync : 07.05.2019

2 files changed, 208 insertions, 2 deletions

diff --git a/profiles/prefix/windows/cygwin/packages b/profiles/prefix/windows/cygwin/packages
index 48b7c0bfe442..0b7db49e865e 100644
--- a/profiles/prefix/windows/cygwin/packages
+++ b/profiles/prefix/windows/cygwin/packages
@@ -1,5 +1,6 @@
-# Copyright 1999-2009 Gentoo Foundation
+# Copyright 1999-2019 Gentoo Foundation
 # Distributed under the terms of the GNU General Public License v2
 
+*app-admin/cygwin-rebase
 *sys-devel/binutils
 *sys-libs/cygwin-crypt
diff --git a/profiles/prefix/windows/cygwin/profile.bashrc b/profiles/prefix/windows/cygwin/profile.bashrc
index f016c87b0d4f..aecfd9adb7c0 100644
--- a/profiles/prefix/windows/cygwin/profile.bashrc
+++ b/profiles/prefix/windows/cygwin/profile.bashrc
@@ -1,4 +1,4 @@
-# Copyright 1999-2017 Gentoo Foundation
+# Copyright 1999-2019 Gentoo Foundation
 # Distributed under the terms of the GNU General Public License v2
 
 if [[ ${CATEGORY}/${PN} == app-arch/xz-utils
@@ -11,3 +11,208 @@ if [[ ${CATEGORY}/${PN} == app-arch/xz-utils
 	# As xz-utils has no need for -isystem here, we can use -I instead.
 	CPPFLAGS=${CPPFLAGS//-isystem /-I}
 fi
+
+post_pkg_preinst() {
+	cygwin-post_pkg_preinst
+}
+
+pre_pkg_postinst() {
+	cygwin-pre_pkg_postinst
+}
+
+post_pkg_prerm() {
+	cygwin-post_pkg_prerm
+}
+
+cygwin-post_pkg_preinst() {
+	cygwin-rebase-post_pkg_preinst
+}
+
+cygwin-pre_pkg_postinst() {
+	cygwin-rebase-pre_pkg_postinst
+}
+
+cygwin-post_pkg_prerm() {
+	cygwin-rebase-post_pkg_prerm
+}
+
+###############################################################################
+# To allow a Windows DLL to reside in memory just once for multiple processes,
+# each process needs to be able to map that DLL at the same base address,
+# without the need for a dynamic rebase.  However, this requires the DLL's
+# base address to be unique across all DLLs potentially loaded into a single
+# process.  Hence the PE/COFF binary format allows to define a preferred base
+# address for DLLs, but leaves it up to the package manager to maintain that
+# base address to be unique across all DLLs related together.
+# (Not sure how exactly ASLR plays in here, though.)
+#
+# Furthermore, for the Cygwin fork, it is crucial that the child process is
+# able to reload a DLL at the very same address as in the parent process.
+# Having unique preferred base addresses across all related DLLs does help
+# here as well.
+#
+# The Cygwin rebase utility does maintain some database holding the size and
+# preferred base address for each DLL, and allows to update a DLL's preferred
+# base address to not conflict with already installed DLLs.
+#
+# As updating the preferred base address for a DLL in use is a bad idea, we
+# need to update the base address while the DLL is in staging directory, and
+# update the rebase database after merging the DLL to the live file system.
+#
+# This allows to define a new preferred base address for a DLL that would
+# replace an existing one, because during fork we really want to use the
+# old version in the child process, which is verified using the preferred
+# base address value to be identical in parent and child process.
+#
+# Otherwise, the new DLL may have identical size and preferred base address
+# as the old DLL, and we may not detect a different DLL in the fork child.
+#
+# For unmerging a DLL: The Cygwin rebase utility does check if a DLL found
+# in the database does still exist, removing that database entry otherwise.
+###############################################################################
+
+cygwin-rebase-get_pendingdir() {
+	echo "var/db/rebase/pending"
+}
+
+cygwin-rebase-get_mergeddir() {
+	echo "var/db/rebase/merged"
+}
+
+cygwin-rebase-get_listname() {
+	echo "dlls_${CATEGORY}_${P}${PR:+-}${PR}"
+}
+
+cygwin-rebase-get_rebase_program() {
+	[[ ${CHOST} == "${CBUILD}" ]] || return 1
+	local pfx
+	for pfx in "${EPREFIX}" "${BROOT:-${PORTAGE_OVERRIDE_EPREFIX}}"
+	do
+		[[ -x ${pfx}/usr/bin/rebase ]] || continue
+		echo "${pfx}/usr/bin/rebase"
+		return 0
+	done
+	return 1
+}
+
+cygwin-rebase-post_pkg_preinst() {
+	# Ensure database is up to date for when dlls were merged but
+	# subsequent cygwin-rebase-merge-pending was not executed.
+	einfo "Cygwin: Merging pending files into rebase database..."
+	cygwin-rebase-merge pending
+	eend $?
+
+	local listname=$(cygwin-rebase-get_listname)
+	local pendingdir=$(cygwin-rebase-get_pendingdir)
+	local rebase_program=$(cygwin-rebase-get_rebase_program)
+
+	if [[ ${CATEGORY}/${PN} == 'app-admin/cygwin-rebase' ]]
+	then
+		local mergeddir=$(cygwin-rebase-get_mergeddir)
+		keepdir "/${pendingdir}"
+		keepdir "/${mergeddir}"
+	fi
+
+	einfo "Cygwin: Rebasing new files..."
+	(
+		set -e
+		cd "${ED}"
+
+		# The list of suffixes is found in the rebaseall script.
+		find . -type f \
+			'(' -name '*.dll' \
+			 -o -name '*.so' \
+			 -o -name '*.oct' \
+			')' \
+		| sed -e "s|^\.|${EPREFIX}|" > "${T}/rebase-filelist"
+		[[ "${PIPESTATUS[*]}" == '0 0' ]]
+
+		# Nothing found to rebase in this package.
+		[[ -s ${T}/rebase-filelist ]] || exit 0
+
+		mkdir -p "./${pendingdir}"
+		cp -f "${T}/rebase-filelist" "./${pendingdir}/${listname}"
+
+		# Without the rebase program, do not perform a rebase.
+		[[ ${rebase_program} ]] || exit 0
+
+		sed -ne "/^${EPREFIX//\//\\/}\\//{s|^${EPREFIX}/||;p}" "./${pendingdir}/${listname}" \
+		| "${rebase_program}" --verbose --oblivious --database --filelist=-
+		[[ "${PIPESTATUS[*]}" == '0 0' ]]
+	)
+	eend $?
+}
+
+cygwin-rebase-pre_pkg_postinst() {
+	if [[ ${CATEGORY}/${PN} == 'app-admin/cygwin-rebase' ]]
+	then
+		einfo "Cygwin: Updating rebase database with installed files..."
+		cygwin-rebase-merge merged
+		eend $?
+	fi
+	einfo "Cygwin: Merging updated files into rebase database..."
+	cygwin-rebase-merge pending
+	eend $?
+}
+
+cygwin-rebase-merge() {
+	local mode=${1}
+
+	local rebase_program=$(cygwin-rebase-get_rebase_program)
+	[[ ${rebase_program} ]] || return 0
+
+	local pendingdir=''
+	local mergeddir=''
+	case ${mode} in
+	pending)
+		pendingdir=$(cygwin-rebase-get_pendingdir)
+		mergeddir=$(cygwin-rebase-get_mergeddir)
+		;;
+	merged)
+		pendingdir=$(cygwin-rebase-get_mergeddir)
+		mergeddir=''
+		;;
+	*)
+		die "Invalid mode '${mode}'."
+		;;
+	esac
+
+	(
+		set -e
+		cd "${EROOT}"
+
+		[[ -r ./${pendingdir}/. ]]
+		[[ -r ./${mergeddir}/. ]]
+
+		find ./"${pendingdir}" -mindepth 1 -maxdepth 1 -type f -name 'dlls_*' \
+			-exec sed -ne "/^${EPREFIX//\//\\/}\\//{s|^${EPREFIX}/||;p}" {} + \
+			| "${rebase_program}" --verbose --merge-files --database --filelist=-
+		[[ "${PIPESTATUS[*]}" == '0 0' ]]
+
+		[[ ${mode} == 'pending' ]] || exit 0
+
+		find "./${pendingdir}" -maxdepth 1 -type f \
+			-exec mv -f -t "./${mergeddir}/" {} +
+	)
+	[[ $? == 0 ]] || die "Merging ${mode} files into rebase database failed."
+}
+
+cygwin-rebase-post_pkg_prerm() {
+	# The pending list is installed as part of the package, but
+	# the merged list is not.  Move from merged back to pending,
+	# in case the unmerge fails...
+	local pendingdir=$(cygwin-rebase-get_pendingdir)
+	local mergeddir=$(cygwin-rebase-get_mergeddir)
+	local listname=$(cygwin-rebase-get_listname)
+	(
+		set -e
+		cd "${EROOT}"
+		[[ -w ./${mergeddir}/. ]]
+		[[ -w ./${pendingdir}/. ]]
+		if [[ -s ./${mergeddir}/${listname} ]]
+		then
+			mv -f "./${mergeddir}/${listname}" "./${pendingdir}/${listname}" || :
+		fi
+		rm -f "./${mergeddir}/${listname}"
+	)
+}