dev-qt/qtcore: Add wall of blockers against <${QT5_PV}

Revdeps can drop dev-qt/* dependencies on version bumps at any time, which then
may lead to Portage disregarding these dev-qt/* packages for upgrade if nothing
is left depending on them. When these packages contain Qt5 plugins it breaks
runtime hard - broken screenlocker, blank login manager, ... -, with:

`Cannot mix incompatible Qt library (5.15.10) with this library (5.15.11)`

We've had this happen with dev-qt/qtvirtualkeyboard and dev-qt/qtcharts already
and gradual porting to Qt6 ensures it will happen more often in the future.

Package groups (https://bugs.gentoo.org/918873) are not effective here as it
concerns ::installed package set.

For lack of a better mechanism from the package manager, these blockers make
sure dep calculation will take care of the necessary cleanup of dangling Qt5
packages, even if it will not improve our backtracking situation.

Signed-off-by: Andreas Sturmlechner <asturm@gentoo.org>

1 files changed, 162 insertions, 0 deletions

diff --git a/dev-qt/qtcore/qtcore-5.15.12-r1.ebuild b/dev-qt/qtcore/qtcore-5.15.12-r1.ebuild
new file mode 100644
index 000000000000..fc74cab8e807
--- /dev/null
+++ b/dev-qt/qtcore/qtcore-5.15.12-r1.ebuild
@@ -0,0 +1,162 @@
+# Copyright 1999-2024 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+if [[ ${PV} != *9999* ]]; then
+	QT5_KDEPATCHSET_REV=1
+	KEYWORDS="~amd64 ~arm ~arm64 ~hppa ~loong ~ppc ~ppc64 ~riscv ~sparc ~x86"
+fi
+
+QT5_MODULE="qtbase"
+inherit linux-info flag-o-matic toolchain-funcs qt5-build
+
+DESCRIPTION="Cross-platform application development framework"
+SLOT=5/${QT5_PV}
+
+IUSE="icu old-kernel"
+
+DEPEND="
+	dev-libs/double-conversion:=
+	dev-libs/glib:2
+	dev-libs/libpcre2[pcre16,unicode]
+	sys-libs/zlib:=
+	icu? ( dev-libs/icu:= )
+	!icu? ( virtual/libiconv )
+"
+RDEPEND="${DEPEND}
+	!<dev-qt/designer-${QT5_PV}:5
+	!<dev-qt/qt3d-${QT5_PV}:5
+	!<dev-qt/qtbluetooth-${QT5_PV}:5
+	!<dev-qt/qtcharts-${QT5_PV}:5
+	!<dev-qt/qtconcurrent-${QT5_PV}:5
+	!<dev-qt/qtdatavis3d-${QT5_PV}:5
+	!<dev-qt/qtdbus-${QT5_PV}:5
+	!<dev-qt/qtdeclarative-${QT5_PV}:5
+	!<dev-qt/qtgamepad-${QT5_PV}:5
+	!<dev-qt/qtgraphicaleffects-${QT5_PV}:5
+	!<dev-qt/qtgui-${QT5_PV}:5
+	!<dev-qt/qthelp-${QT5_PV}:5
+	!<dev-qt/qtimageformats-${QT5_PV}:5
+	!<dev-qt/qtlocation-${QT5_PV}:5
+	!<dev-qt/qtmultimedia-${QT5_PV}:5
+	!<dev-qt/qtnetwork-${QT5_PV}:5
+	!<dev-qt/qtnetworkauth-${QT5_PV}:5
+	!<dev-qt/qtopengl-${QT5_PV}:5
+	!<dev-qt/qtpositioning-${QT5_PV}:5
+	!<dev-qt/qtprintsupport-${QT5_PV}:5
+	!<dev-qt/qtquickcontrols-${QT5_PV}:5
+	!<dev-qt/qtquickcontrols2-${QT5_PV}:5
+	!<dev-qt/qtquicktimeline-${QT5_PV}:5
+	!<dev-qt/qtscript-${QT5_PV}:5
+	!<dev-qt/qtscxml-${QT5_PV}:5
+	!<dev-qt/qtsensors-${QT5_PV}:5
+	!<dev-qt/qtserialbus-${QT5_PV}:5
+	!<dev-qt/qtserialport-${QT5_PV}:5
+	!<dev-qt/qtspeech-${QT5_PV}:5
+	!<dev-qt/qtsql-${QT5_PV}:5
+	!<dev-qt/qtsvg-${QT5_PV}:5
+	!<dev-qt/qttest-${QT5_PV}:5
+	!<dev-qt/qtvirtualkeyboard-${QT5_PV}:5
+	!<dev-qt/qtwayland-${QT5_PV}:5
+	!<dev-qt/qtwebchannel-${QT5_PV}:5
+	!<dev-qt/qtwebengine-${QT5_PV}:5
+	!<dev-qt/qtwebsockets-${QT5_PV}:5
+	!<dev-qt/qtwebview-${QT5_PV}:5
+	!<dev-qt/qtwidgets-${QT5_PV}:5
+	!<dev-qt/qtx11extras-${QT5_PV}:5
+	!<dev-qt/qtxml-${QT5_PV}:5
+	!<dev-qt/qtxmlpatterns-${QT5_PV}:5
+"
+
+QT5_TARGET_SUBDIRS=(
+	src/tools/bootstrap
+	src/tools/moc
+	src/tools/rcc
+	src/corelib
+	src/tools/qlalr
+	doc
+)
+
+QT5_GENTOO_PRIVATE_CONFIG=(
+	!:network
+	!:sql
+	!:testlib
+	!:xml
+)
+
+pkg_pretend() {
+	use kernel_linux || return
+	get_running_version
+	if kernel_is -lt 4 11 && ! use old-kernel; then
+		ewarn "The running kernel is older than 4.11. USE=old-kernel is needed for"
+		ewarn "dev-qt/qtcore to function on this kernel properly. Bugs #669994, #672856"
+	fi
+}
+
+src_prepare() {
+	# don't add -O3 to CXXFLAGS, bug 549140
+	sed -i -e '/CONFIG\s*+=/s/optimize_full//' src/corelib/corelib.pro || die
+
+	# fix missing qt_version_tag symbol w/ LTO, bug 674382
+	sed -i -e 's/^gcc:ltcg/gcc/' src/corelib/global/global.pri || die
+
+	# Broken with FORTIFY_SOURCE=3
+	#
+	# Our toolchain sets F_S=2 by default w/ >= -O2, so we need
+	# to unset F_S first, then explicitly set 2, to negate any default
+	# and anything set by the user if they're choosing 3 (or if they've
+	# modified GCC to set 3).
+	#
+	# Refs:
+	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105078
+	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105709
+	# https://bugreports.qt.io/browse/QTBUG-103782
+	# bug #847145
+	if tc-enables-fortify-source ; then
+		# We can't unconditionally do this b/c we fortify needs
+		# some level of optimisation.
+		filter-flags -D_FORTIFY_SOURCE=3
+		# (Qt doesn't seem to respect CPPFLAGS?)
+		append-flags -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2
+	fi
+
+	qt5-build_src_prepare
+
+	# workaround for a79a370c (...Annotate-QMutex-...patch) adding a header
+	qt5_syncqt_version
+}
+
+src_configure() {
+	local myconf=(
+		$(qt_use icu)
+		$(qt_use !icu iconv)
+	)
+	use old-kernel && myconf+=(
+		-no-feature-renameat2 # needs Linux 3.16, bug 669994
+		-no-feature-getentropy # needs Linux 3.17, bug 669994
+		-no-feature-statx # needs Linux 4.11, bug 672856
+	)
+	qt5-build_src_configure
+}
+
+src_install() {
+	qt5-build_src_install
+	qt5_symlink_binary_to_path qmake 5
+
+	local flags=(
+		DBUS FREETYPE IMAGEFORMAT_JPEG IMAGEFORMAT_PNG
+		OPENGL OPENSSL SSL WIDGETS
+	)
+
+	for flag in ${flags[@]}; do
+		cat >> "${D}"/${QT5_HEADERDIR}/QtCore/qconfig.h <<- _EOF_ || die
+
+			#if defined(QT_NO_${flag}) && defined(QT_${flag})
+			# undef QT_NO_${flag}
+			#elif !defined(QT_NO_${flag}) && !defined(QT_${flag})
+			# define QT_NO_${flag}
+			#endif
+		_EOF_
+	done
+}