sys-devel/clang-bloomberg-p2996: new package, add 9999

Adds a monolithic ebuild for the experimental clang fork by Bloomberg implementing P2996 (Reflection for C++26). It is cobbled together — somewhat arbitrarily — from the various split ebuilds in the main portage tree and builds clang, libc++, and libc++abi, which are installed into /usr/lib/{clang,llvm}/bloomberg-p2996. Two patches address compiler warnings that trigger QA notices. The remaining QA notices are likely false positives. Signed-off-by: Florian Albrechtskirchinger <falbrechtskirchinger@gmail.com>
2026-07-09 23:23:00 -04:00 · 2025-07-21 17:18:56 +02:00
parent 9c57b6d52a
commit f6700f7900
5 changed files with 286 additions and 0 deletions
--- a/sys-devel/clang-bloomberg-p2996/clang-bloomberg-p2996-9999.ebuild
+++ b/sys-devel/clang-bloomberg-p2996/clang-bloomberg-p2996-9999.ebuild
@@ -0,0 +1,234 @@
+# Copyright 2025 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+inherit cmake git-r3 prefix python-utils-r1
+
+DESCRIPTION="Clang fork implementing experimental support for P2996 (Reflection for C++26)"
+HOMEPAGE="https://github.com/bloomberg/clang-p2996"
+
+LICENSE="Apache-2.0-with-LLVM-exceptions UoI-NCSA BSD MIT public-domain rc"
+SLOT="0"
+KEYWORDS=""
+
+EGIT_REPO_URI="https://github.com/bloomberg/clang-p2996.git"
+EGIT_BRANCH="p2996"
+
+ALL_LLVM_TARGETS="AArch64 AMDGPU ARC ARM AVR BPF CSKY DirectX Hexagon Lanai LoongArch M68k MSP430 Mips NVPTX PowerPC RISCV SPIRV Sparc SystemZ VE WebAssembly +X86 XCore Xtensa"
+IUSE="+debug +default-reflection-latest-on +pie"
+for target in ${ALL_LLVM_TARGETS}; do
+	IUSE+=" ${target%${target#+}}llvm_targets_${target#+}"
+done
+
+# TODO
+RDEPEND="sys-libs/zlib:0="
+DEPEND="${RDEPEND}"
+
+PATCHES=(
+	"${FILESDIR}/unknown-reflection.patch"
+	"${FILESDIR}/uninitialized.patch"
+)
+
+CMAKE_USE_DIR="$S/llvm"
+
+src_prepare() {
+	# create extra parent dir for relative CLANG_RESOURCE_DIR access
+	mkdir -p x/y || die
+	BUILD_DIR=${WORKDIR}/x/y/clang
+
+	use default-reflection-latest-on && eapply "${FILESDIR}/enable-reflection-latest.patch"
+
+	cmake_src_prepare
+
+	# add Gentoo Portage Prefix for Darwin (see prefix-dirs.patch)
+	eprefixify \
+		clang/lib/Lex/InitHeaderSearch.cpp \
+		clang/lib/Driver/ToolChains/Darwin.cpp || die
+
+	if ! use prefix-guest && [[ -n ${EPREFIX} ]]; then
+		sed -i "/LibDir.*Loader/s@return \"\/\"@return \"${EPREFIX}/\"@" clang/lib/Driver/ToolChains/Linux.cpp || die
+	fi
+}
+
+src_configure() {
+	local targets=()
+	for target in ${ALL_LLVM_TARGETS}; do
+		use llvm_targets_${target#+} && targets+=("${target#+}")
+	done
+	if [ ${#targets[@]} -eq 0 ]; then
+		die "At least one LLVM target must be enabled"
+	fi
+
+	local libdir=$(get_libdir)
+	local mycmakeargs=(
+		-DDEFAULT_SYSROOT=$(usex prefix-guest "" "${EPREFIX}")
+		-DCMAKE_CXX_COMPILER_TARGET="${CHOST}"
+		-DCMAKE_INSTALL_PREFIX="${EPREFIX}/usr/lib/llvm/bloomberg-p2996"
+		-DLLVM_LIBDIR_SUFFIX=${libdir#lib}
+
+		-DBUILD_SHARED_LIBS=OFF
+		-DLLVM_HOST_TRIPLE="${CHOST}"
+		-DLLVM_BUILD_LLVM_DYLIB=ON
+		-DLLVM_LINK_LLVM_DYLIB=ON
+		-DLLVM_ENABLE_PROJECTS="clang"
+		-DLLVM_ENABLE_RUNTIMES="libcxxabi;libcxx"
+		-DLLVM_TARGETS_TO_BUILD="$(IFS=';' ; echo "${targets[*]}")"
+		-DLLVM_INCLUDE_BENCHMARKS=OFF
+		-DLLVM_INCLUDE_TESTS=OFF
+		-DLLVM_BUILD_TESTS=OFF
+		-DLLVM_INSTALL_GTEST=OFF
+
+		-DLLVM_ENABLE_ASSERTIONS=$(usex debug)
+		-DLLVM_ENABLE_EH=ON
+		-DLLVM_ENABLE_RTTI=ON
+		-DLLVM_ENABLE_ZLIB=FORCE_ON
+
+		-DLIBCXX_ENABLE_SHARED=ON
+		-DLIBCXX_ENABLE_STATIC=OFF
+		-DLIBCXX_CXX_ABI=libcxxabi
+		-DLIBCXX_USE_COMPILER_RT=OFF
+		-DLIBCXX_HAS_GCC_S_LIB=OFF
+		-DLIBCXX_INCLUDE_BENCHMARKS=OFF
+		-DLIBCXX_INCLUDE_TESTS=OFF
+		-DLIBCXXABI_LIBUNWIND_INCLUDES="${EPREFIX}"/usr/include
+		-DLIBCXXABI_USE_LLVM_UNWINDER=OFF
+
+		-DCLANG_CONFIG_FILE_SYSTEM_DIR="${EPREFIX}/etc/clang/bloomberg-p2996"
+		-DCLANG_CONFIG_FILE_USER_DIR="~/.config/clang-bloomberg-p2996"
+		# relative to bindir
+		-DCLANG_RESOURCE_DIR="../../../../lib/clang/bloomberg-p2996"
+		-DCLANG_LINK_CLANG_DYLIB=ON
+		-DCLANG_INCLUDE_TESTS=OFF
+
+		-DCLANG_DEFAULT_OPENMP_RUNTIME=libomp
+		-DCLANG_DEFAULT_PIE_ON_LINUX=$(usex pie)
+
+		-DPython3_EXECUTABLE="${PYTHON}"
+
+		-DOCAMLFIND=NO
+	)
+
+	use debug || local -x CPPFLAGS="${CPPFLAGS} -DNDEBUG"
+	cmake_src_configure
+}
+
+src_compile() {
+	cmake_src_compile
+}
+
+_doclang_cfg() {
+	local triple="${1}"
+
+	local tool
+	for tool in clang{,++,-cpp}; do
+		newins - "${triple}-${tool}.cfg" <<-EOF
+			# This configuration file is used by ${triple}-${tool} driver.
+			@../${triple}-${tool}.cfg
+			@gentoo-plugins.cfg
+			@gentoo-runtimes.cfg
+		EOF
+
+		if [[ ! -f "${ED}/etc/clang/bloomberg-p2996/bloomberg-p2996-${tool}.cfg" ]]; then
+			dosym "${triple}-${tool}.cfg" "/etc/clang/bloomberg-p2996/bloomberg-p2996-${tool}.cfg"
+		fi
+	done
+
+	# Install symlinks for triples with other vendor strings since some
+	# programs insist on mangling the triple.
+	local vendor
+	for vendor in gentoo pc unknown; do
+		local vendor_triple="${triple%%-*}-${vendor}-${triple#*-*-}"
+		for tool in clang{,++,-cpp}; do
+			if [[ ! -f "${ED}/etc/clang/bloomberg-p2996/${vendor_triple}-${tool}.cfg" ]]; then
+				dosym "${triple}-${tool}.cfg" "/etc/clang/bloomberg-p2996/${vendor_triple}-${tool}.cfg"
+			fi
+		done
+	done
+}
+
+doclang_cfg() {
+	#local triple=$(get_abi_CHOST "${abi}")
+	local triple=${CHOST}
+
+	_doclang_cfg ${triple}
+
+	# LLVM may have different arch names in some cases. For example in x86
+	# profiles the triple uses i686, but llvm will prefer i386 if invoked
+	# with "clang" on x86 or "clang -m32" on x86_64. The gentoo triple will
+	# be used if invoked through ${CHOST}-clang{,++,-cpp} though.
+	#
+	# To make sure the correct triples are installed,
+	# see Triple::getArchTypeName() in llvm/lib/TargetParser/Triple.cpp
+	# and compare with CHOST values in profiles.
+
+	local abi=${triple%%-*}
+	case ${abi} in
+		armv4l|armv4t|armv5tel|armv6j|armv7a)
+			_doclang_cfg ${triple/${abi}/arm}
+			;;
+		i686)
+			_doclang_cfg ${triple/${abi}/i386}
+			;;
+		sparc)
+			_doclang_cfg ${triple/${abi}/sparcel}
+			;;
+		sparc64)
+			_doclang_cfg ${triple/${abi}/sparcv9}
+			;;
+	esac
+}
+
+src_install() {
+	cmake_src_install
+
+	# Rename programs and update symlinks
+	cd "${D}/usr/lib/llvm/bloomberg-p2996/bin" || die
+	for file in *; do
+		if [[ -f "${file}" && -x "${file}" && ! -L "${file}" ]]; then
+			# Rename regular, executable files
+			mv "${file}" "bloomberg-p2996-${file}" || die "Failed to rename ${file}"
+		elif [[ -L "${file}" ]]; then
+			# Update symlink to point to renamed target
+			local target
+			target=$(readlink "${file}") || die "Failed to read symlink ${file}"
+			ln -sf "bloomberg-p2996-${target}" "bloomberg-p2996-${file}" || die "Failed to update symlink ${file}"
+			rm "${file}" || die "Failed to remove original symlink ${file}"
+		fi
+	done
+
+	local ldpath="${EPREFIX}/usr/lib/llvm/bloomberg-p2996/$(get_libdir)"
+	newenvd - "60llvm-bloomberg-p2996" <<-_EOF_
+		PATH="${EPREFIX}/usr/lib/llvm/bloomberg-p2996/bin"
+		# we need to duplicate it in ROOTPATH for Portage to respect...
+		ROOTPATH="${EPREFIX}/usr/lib/llvm/bloomberg-p2996/bin"
+		LDPATH="${ldpath}:${ldpath}/${CHOST}"
+	_EOF_
+
+	insinto "/etc/clang/bloomberg-p2996"
+	newins - gentoo-runtimes.cfg <<-EOF
+		# This file is initially generated by sys-devel/clang-bloomberg-p2996::guru.
+		# It is used to control the default runtimes using by clang.
+
+		--rtlib=libgcc
+		--unwindlib=libgcc
+		--stdlib=libc++
+		-fuse-ld=bfd
+		-L${ldpath}/${CHOST}
+	EOF
+	newins - gentoo-plugins.cfg <<-EOF
+		# This file is used to load optional LLVM plugins.
+	EOF
+
+	doclang_cfg
+
+	rm -r "${D}/usr/share/man" || die
+}
+
+pkg_postinst() {
+	elog "Binaries are installed with a 'bloomberg-p2996-' prefix,"
+	elog "e.g., bloomberg-p2996-clang++."
+	use default-reflection-latest-on && \
+		elog "Pass -fno-reflection-latest to disable reflection support." || \
+		elog "Pass -freflection-latest to enable reflection support."
+}
--- a/sys-devel/clang-bloomberg-p2996/files/enable-reflection-latest.patch
+++ b/sys-devel/clang-bloomberg-p2996/files/enable-reflection-latest.patch
@@ -0,0 +1,13 @@
+diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
+index a7af861541b8..d372914dfaaf 100644
+--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
+@@ -7066,7 +7066,7 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
+   Args.AddLastArg(CmdArgs, options::OPT_fapinotes_swift_version);
+ 
+   if (Args.hasFlag(options::OPT_freflection_latest,
+-                   options::OPT_fno_reflection_latest, false)) {
+                   options::OPT_fno_reflection_latest, true)) {
+     CmdArgs.push_back("-freflection");
+     CmdArgs.push_back("-fparameter-reflection");
+     CmdArgs.push_back("-fannotation-attributes");
--- a/sys-devel/clang-bloomberg-p2996/files/uninitialized.patch
+++ b/sys-devel/clang-bloomberg-p2996/files/uninitialized.patch
@@ -0,0 +1,13 @@
+diff --git a/llvm/include/llvm/ObjectYAML/ELFYAML.h b/llvm/include/llvm/ObjectYAML/ELFYAML.h
+index e883f2f3e144..1089feab39ea 100644
+--- a/llvm/include/llvm/ObjectYAML/ELFYAML.h
+++ b/llvm/include/llvm/ObjectYAML/ELFYAML.h
+@@ -275,7 +275,7 @@ struct Section : public Chunk {
+   std::optional<llvm::yaml::Hex64> Size;
+ 
+   // Holds the original section index.
+-  unsigned OriginalSecNdx;
+  unsigned OriginalSecNdx = 0;
+ 
+   Section(ChunkKind Kind, bool IsImplicit = false) : Chunk(Kind, IsImplicit) {}
+ 
--- a/sys-devel/clang-bloomberg-p2996/files/unknown-reflection.patch
+++ b/sys-devel/clang-bloomberg-p2996/files/unknown-reflection.patch
@@ -0,0 +1,12 @@
+diff --git a/clang/lib/AST/ExprConstantMeta.cpp b/clang/lib/AST/ExprConstantMeta.cpp
+index 0808f3124833..bc23ad41dbe5 100644
+--- a/clang/lib/AST/ExprConstantMeta.cpp
+++ b/clang/lib/AST/ExprConstantMeta.cpp
+@@ -1664,6 +1664,7 @@ StringRef DescriptionOf(APValue RV, bool Granular = true) {
+     return "an annotation";
+   }
+   }
+  llvm_unreachable("unknown reflection");
+ }
+ 
+ bool DiagnoseReflectionKind(DiagFn Diagnoser, SourceRange Range,
--- a/sys-devel/clang-bloomberg-p2996/metadata.xml
+++ b/sys-devel/clang-bloomberg-p2996/metadata.xml
@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE pkgmetadata SYSTEM "https://www.gentoo.org/dtd/metadata.dtd">
+<pkgmetadata>
+  <maintainer type="person">
+    <email>falbrechtskirchinger@gmail.com</email>
+    <name>Florian Albrechtskirchinger</name>
+  </maintainer>
+  <use>
+    <flag name="default-reflection-latest-on">Defaults -freflection-latest to on.</flag>
+  </use>
+  <upstream>
+    <remote-id type="github">bloomberg/clang-p2996</remote-id>
+  </upstream>
+</pkgmetadata>