[gentoo-commits] repo/gentoo:master commit in: sys-devel/llvm/files/, sys-devel/llvm/

[Michał Górny]

commit:     4ea0768355d83631d0baf5c7de9b712ea2ebe12a
Author:     Michał Górny <mgorny <AT> gentoo <DOT> org>
AuthorDate: Sun Dec 27 22:47:38 2015 +0000
Commit:     Michał Górny <mgorny <AT> gentoo <DOT> org>
CommitDate: Sun Dec 27 22:51:59 2015 +0000
URL:        https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=4ea07683

sys-devel/llvm: Backport msan fix for 4.1+ kernels, bug #569894

 .../llvm/files/compiler-rt-3.7-msan-fix.patch      |  86 ++++
 sys-devel/llvm/files/llvm-3.7-msan-fix.patch       |  79 +++
 sys-devel/llvm/llvm-3.7.0-r5.ebuild                | 540 +++++++++++++++++++++
 3 files changed, 705 insertions(+)

diff --git a/sys-devel/llvm/files/compiler-rt-3.7-msan-fix.patch b/sys-devel/llvm/files/compiler-rt-3.7-msan-fix.patch
new file mode 100644
index 0000000..3854a18
--- /dev/null
+++ b/sys-devel/llvm/files/compiler-rt-3.7-msan-fix.patch
@@ -0,0 +1,86 @@
+From 5dad120f9c9bc74c73edadb0467d8df81ae46066 Mon Sep 17 00:00:00 2001
+From: "H.J. Lu" <hjl.tools@×××××.com>
+Date: Wed, 5 Aug 2015 05:34:27 -0700
+Subject: [PATCH 08/13] Apply split-layout-compiler-rt.patch
+
+https://llvm.org/bugs/show_bug.cgi?id=24155
+---
+ lib/msan/msan.h            | 30 ++++++++++++++++++++----------
+ lib/msan/msan_allocator.cc | 12 +++++++++++-
+ 2 files changed, 31 insertions(+), 11 deletions(-)
+
+diff --git a/lib/msan/msan.h b/lib/msan/msan.h
+index cd8bc19..6251b38 100644
+--- a/lib/msan/msan.h
++++ b/lib/msan/msan.h
+@@ -94,17 +94,27 @@ const MappingDesc kMemoryLayout[] = {
+ 
+ #elif SANITIZER_LINUX && SANITIZER_WORDSIZE == 64
+ 
+-// Requries PIE binary and ASLR enabled.
+-// Main thread stack and DSOs at 0x7f0000000000 (sometimes 0x7e0000000000).
+-// Heap at 0x600000000000.
++// All of the following configurations are supported.
++// ASLR disabled: main executable and DSOs at 0x555550000000
++// PIE and ASLR: main executable and DSOs at 0x7f0000000000
++// non-PIE: main executable below 0x100000000, DSOs at 0x7f0000000000
++// Heap at 0x700000000000.
+ const MappingDesc kMemoryLayout[] = {
+-    {0x000000000000ULL, 0x200000000000ULL, MappingDesc::INVALID, "invalid"},
+-    {0x200000000000ULL, 0x400000000000ULL, MappingDesc::SHADOW, "shadow"},
+-    {0x400000000000ULL, 0x600000000000ULL, MappingDesc::ORIGIN, "origin"},
+-    {0x600000000000ULL, 0x800000000000ULL, MappingDesc::APP, "app"}};
+-
+-#define MEM_TO_SHADOW(mem) (((uptr)(mem)) & ~0x400000000000ULL)
+-#define SHADOW_TO_ORIGIN(mem) (((uptr)(mem)) + 0x200000000000ULL)
++    {0x000000000000ULL, 0x050000000000ULL, MappingDesc::APP, "app-1"},
++    {0x050000000000ULL, 0x100000000000ULL, MappingDesc::SHADOW, "shadow-2"},
++    {0x100000000000ULL, 0x150000000000ULL, MappingDesc::INVALID, "invalid"},
++    {0x150000000000ULL, 0x200000000000ULL, MappingDesc::ORIGIN, "origin-2"},
++    {0x200000000000ULL, 0x300000000000ULL, MappingDesc::SHADOW, "shadow-3"},
++    {0x300000000000ULL, 0x400000000000ULL, MappingDesc::ORIGIN, "origin-3"},
++    {0x400000000000ULL, 0x500000000000ULL, MappingDesc::INVALID, "invalid"},
++    {0x500000000000ULL, 0x550000000000ULL, MappingDesc::SHADOW, "shadow-1"},
++    {0x550000000000ULL, 0x600000000000ULL, MappingDesc::APP, "app-2"},
++    {0x600000000000ULL, 0x650000000000ULL, MappingDesc::ORIGIN, "origin-1"},
++    {0x650000000000ULL, 0x700000000000ULL, MappingDesc::INVALID, "invalid"},
++    {0x700000000000ULL, 0x800000000000ULL, MappingDesc::APP, "app-3"}};
++
++#define MEM_TO_SHADOW(mem) (((uptr)(mem)) ^ 0x500000000000ULL)
++#define SHADOW_TO_ORIGIN(mem) (((uptr)(mem)) + 0x100000000000ULL)
+ 
+ #else
+ #error "Unsupported platform"
+diff --git a/lib/msan/msan_allocator.cc b/lib/msan/msan_allocator.cc
+index 6df3566..e588bf8 100644
+--- a/lib/msan/msan_allocator.cc
++++ b/lib/msan/msan_allocator.cc
+@@ -49,7 +49,8 @@ struct MsanMapUnmapCallback {
+   typedef SizeClassAllocator32<0, SANITIZER_MMAP_RANGE_SIZE, sizeof(Metadata),
+                                SizeClassMap, kRegionSizeLog, ByteMap,
+                                MsanMapUnmapCallback> PrimaryAllocator;
+-#elif defined(__x86_64__)
++
++#elif SANITIZER_FREEBSD && SANITIZER_WORDSIZE == 64
+   static const uptr kAllocatorSpace = 0x600000000000ULL;
+   static const uptr kAllocatorSize   = 0x80000000000;  // 8T.
+   static const uptr kMetadataSize  = sizeof(Metadata);
+@@ -67,6 +68,15 @@ struct MsanMapUnmapCallback {
+   typedef SizeClassAllocator64<kAllocatorSpace, kAllocatorSize, kMetadataSize,
+                              DefaultSizeClassMap,
+                              MsanMapUnmapCallback> PrimaryAllocator;
++#elif SANITIZER_LINUX && SANITIZER_WORDSIZE == 64
++  static const uptr kAllocatorSpace = 0x700000000000ULL;
++  static const uptr kAllocatorSize   = 0x80000000000;  // 8T.
++  static const uptr kMetadataSize  = sizeof(Metadata);
++  static const uptr kMaxAllowedMallocSize = 8UL << 30;
++
++  typedef SizeClassAllocator64<kAllocatorSpace, kAllocatorSize, kMetadataSize,
++                             DefaultSizeClassMap,
++                             MsanMapUnmapCallback> PrimaryAllocator;
+ #endif
+ typedef SizeClassAllocatorLocalCache<PrimaryAllocator> AllocatorCache;
+ typedef LargeMmapAllocator<MsanMapUnmapCallback> SecondaryAllocator;
+-- 
+2.6.4
+

diff --git a/sys-devel/llvm/files/llvm-3.7-msan-fix.patch b/sys-devel/llvm/files/llvm-3.7-msan-fix.patch
new file mode 100644
index 0000000..e44baa8
--- /dev/null
+++ b/sys-devel/llvm/files/llvm-3.7-msan-fix.patch
@@ -0,0 +1,79 @@
+From 8b0f2fff6e080c053e4fd94d44a694768b8c156e Mon Sep 17 00:00:00 2001
+From: "H.J. Lu" <hjl.tools@×××××.com>
+Date: Wed, 5 Aug 2015 05:35:26 -0700
+Subject: [PATCH 78/84] Apply split-layout-llvm.patch
+
+https://llvm.org/bugs/show_bug.cgi?id=24155
+---
+ lib/Transforms/Instrumentation/MemorySanitizer.cpp | 31 ++++++++++++++++------
+ 1 file changed, 23 insertions(+), 8 deletions(-)
+
+diff --git a/lib/Transforms/Instrumentation/MemorySanitizer.cpp b/lib/Transforms/Instrumentation/MemorySanitizer.cpp
+index 286a563..2ab8bfc 100644
+--- a/lib/Transforms/Instrumentation/MemorySanitizer.cpp
++++ b/lib/Transforms/Instrumentation/MemorySanitizer.cpp
+@@ -194,6 +194,12 @@ static cl::opt<bool> ClCheckConstantShadow("msan-check-constant-shadow",
+ static const char *const kMsanModuleCtorName = "msan.module_ctor";
+ static const char *const kMsanInitName = "__msan_init";
+ 
++static cl::opt<bool> ClSplitLayout(
++    "msan-split-layout", cl::desc(
++                             "use experimental memory layout compatible with "
++                             "non-pie and non-aslr execution"),
++    cl::Hidden, cl::init(true));
++
+ namespace {
+ 
+ // Memory map parameters used in application-to-shadow address calculation.
+@@ -228,6 +234,13 @@ static const MemoryMapParams Linux_X86_64_MemoryMapParams = {
+   0x200000000000,  // OriginBase
+ };
+ 
++static const MemoryMapParams Linux_X86_64_Split_MemoryMapParams = {
++  0,               // AndMask (not used)
++  0x500000000000,  // XorMask
++  0,               // ShadowBase (not used)
++  0x100000000000,  // OriginBase
++};
++
+ // mips64 Linux
+ static const MemoryMapParams Linux_MIPS64_MemoryMapParams = {
+   0x004000000000,  // AndMask
+@@ -483,7 +496,8 @@ bool MemorySanitizer::doInitialization(Module &M) {
+     case Triple::Linux:
+       switch (TargetTriple.getArch()) {
+         case Triple::x86_64:
+-          MapParams = Linux_X86_MemoryMapParams.bits64;
++          MapParams = ClSplitLayout ? &Linux_X86_64_Split_MemoryMapParams
++                                    : Linux_X86_MemoryMapParams.bits64;
+           break;
+         case Triple::x86:
+           MapParams = Linux_X86_MemoryMapParams.bits32;
+@@ -893,16 +907,17 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
+   ///
+   /// Offset = (Addr & ~AndMask) ^ XorMask
+   Value *getShadowPtrOffset(Value *Addr, IRBuilder<> &IRB) {
++    Value *OffsetLong = IRB.CreatePointerCast(Addr, MS.IntptrTy);
++
+     uint64_t AndMask = MS.MapParams->AndMask;
+-    assert(AndMask != 0 && "AndMask shall be specified");
+-    Value *OffsetLong =
+-      IRB.CreateAnd(IRB.CreatePointerCast(Addr, MS.IntptrTy),
+-                    ConstantInt::get(MS.IntptrTy, ~AndMask));
++    if (AndMask)
++      OffsetLong =
++          IRB.CreateAnd(OffsetLong, ConstantInt::get(MS.IntptrTy, ~AndMask));
+ 
+     uint64_t XorMask = MS.MapParams->XorMask;
+-    if (XorMask != 0)
+-      OffsetLong = IRB.CreateXor(OffsetLong,
+-                                 ConstantInt::get(MS.IntptrTy, XorMask));
++    if (XorMask)
++      OffsetLong =
++          IRB.CreateXor(OffsetLong, ConstantInt::get(MS.IntptrTy, XorMask));
+     return OffsetLong;
+   }
+ 
+-- 
+2.6.4
+

diff --git a/sys-devel/llvm/llvm-3.7.0-r5.ebuild b/sys-devel/llvm/llvm-3.7.0-r5.ebuild
new file mode 100644
index 0000000..cc86192
--- /dev/null
+++ b/sys-devel/llvm/llvm-3.7.0-r5.ebuild
@@ -0,0 +1,540 @@
+# Copyright 1999-2015 Gentoo Foundation
+# Distributed under the terms of the GNU General Public License v2
+# $Id$
+
+EAPI=5
+
+: ${CMAKE_MAKEFILE_GENERATOR:=ninja}
+PYTHON_COMPAT=( python2_7 )
+
+inherit check-reqs cmake-utils eutils flag-o-matic multilib \
+	multilib-minimal python-single-r1 toolchain-funcs pax-utils
+
+DESCRIPTION="Low Level Virtual Machine"
+HOMEPAGE="http://llvm.org/"
+SRC_URI="http://llvm.org/releases/${PV}/${P}.src.tar.xz
+	clang? ( http://llvm.org/releases/${PV}/compiler-rt-${PV}.src.tar.xz
+		http://llvm.org/releases/${PV}/cfe-${PV}.src.tar.xz
+		http://llvm.org/releases/${PV}/clang-tools-extra-${PV}.src.tar.xz )
+	lldb? ( http://llvm.org/releases/${PV}/lldb-${PV}.src.tar.xz )
+	!doc? ( http://dev.gentoo.org/~voyageur/distfiles/${P}-manpages.tar.bz2 )"
+
+LICENSE="UoI-NCSA"
+SLOT="0/${PV}"
+KEYWORDS="~amd64 ~arm ~arm64 ~ppc ~ppc64 ~sparc ~x86 ~amd64-fbsd ~x86-fbsd ~x64-freebsd ~amd64-linux ~arm-linux ~x86-linux ~ppc-macos ~x64-macos ~x86-macos"
+IUSE="clang debug doc gold libedit +libffi lldb multitarget ncurses ocaml
+	python +static-analyzer test xml video_cards_radeon kernel_Darwin"
+
+COMMON_DEPEND="
+	sys-libs/zlib:0=
+	clang? (
+		python? ( ${PYTHON_DEPS} )
+		static-analyzer? (
+			dev-lang/perl:*
+			${PYTHON_DEPS}
+		)
+		xml? ( dev-libs/libxml2:2=[${MULTILIB_USEDEP}] )
+	)
+	gold? ( >=sys-devel/binutils-2.22:*[cxx] )
+	libedit? ( dev-libs/libedit:0=[${MULTILIB_USEDEP}] )
+	libffi? ( >=virtual/libffi-3.0.13-r1:0=[${MULTILIB_USEDEP}] )
+	ncurses? ( >=sys-libs/ncurses-5.9-r3:0=[${MULTILIB_USEDEP}] )
+	ocaml? (
+		>=dev-lang/ocaml-4.00.0:0=
+		dev-ml/findlib
+		dev-ml/ocaml-ctypes
+		!!<=sys-devel/llvm-3.7.0-r1[ocaml] )"
+# configparser-3.2 breaks the build (3.3 or none at all are fine)
+DEPEND="${COMMON_DEPEND}
+	dev-lang/perl
+	>=sys-devel/make-3.81
+	>=sys-devel/flex-2.5.4
+	>=sys-devel/bison-1.875d
+	|| ( >=sys-devel/gcc-3.0 >=sys-devel/llvm-3.5
+		( >=sys-freebsd/freebsd-lib-9.1-r10 sys-libs/libcxx )
+	)
+	|| ( >=sys-devel/binutils-2.18 >=sys-devel/binutils-apple-5.1 )
+	kernel_Darwin? ( sys-libs/libcxx )
+	clang? ( xml? ( virtual/pkgconfig ) )
+	doc? ( dev-python/sphinx )
+	gold? ( sys-libs/binutils-libs )
+	libffi? ( virtual/pkgconfig )
+	lldb? ( dev-lang/swig )
+	!!<dev-python/configparser-3.3.0.2
+	ocaml? ( test? ( dev-ml/ounit ) )
+	${PYTHON_DEPS}"
+RDEPEND="${COMMON_DEPEND}
+	clang? ( !<=sys-devel/clang-${PV}-r99 )
+	abi_x86_32? ( !<=app-emulation/emul-linux-x86-baselibs-20130224-r2
+		!app-emulation/emul-linux-x86-baselibs[-abi_x86_32(-)] )"
+PDEPEND="clang? ( =sys-devel/clang-${PV}-r100 )"
+
+# pypy gives me around 1700 unresolved tests due to open file limit
+# being exceeded. probably GC does not close them fast enough.
+REQUIRED_USE="${PYTHON_REQUIRED_USE}
+	lldb? ( clang xml )"
+
+S=${WORKDIR}/${P/_}.src
+
+pkg_pretend() {
+	# in megs
+	# !clang !debug !multitarget -O2       400
+	# !clang !debug  multitarget -O2       550
+	#  clang !debug !multitarget -O2       950
+	#  clang !debug  multitarget -O2      1200
+	# !clang  debug  multitarget -O2      5G
+	#  clang !debug  multitarget -O0 -g  12G
+	#  clang  debug  multitarget -O2     16G
+	#  clang  debug  multitarget -O0 -g  14G
+
+	local build_size=550
+	use clang && build_size=1200
+
+	if use debug; then
+		ewarn "USE=debug is known to increase the size of package considerably"
+		ewarn "and cause the tests to fail."
+		ewarn
+
+		(( build_size *= 14 ))
+	elif is-flagq '-g?(gdb)?([1-9])'; then
+		ewarn "The C++ compiler -g option is known to increase the size of the package"
+		ewarn "considerably. If you run out of space, please consider removing it."
+		ewarn
+
+		(( build_size *= 10 ))
+	fi
+
+	# Multiply by number of ABIs :).
+	local abis=( $(multilib_get_enabled_abis) )
+	(( build_size *= ${#abis[@]} ))
+
+	local CHECKREQS_DISK_BUILD=${build_size}M
+	check-reqs_pkg_pretend
+
+	if [[ ${MERGE_TYPE} != binary ]]; then
+		echo 'int main() {return 0;}' > "${T}"/test.cxx || die
+		ebegin "Trying to build a C++11 test program"
+		if ! $(tc-getCXX) -std=c++11 -o /dev/null "${T}"/test.cxx; then
+			eerror "LLVM-${PV} requires C++11-capable C++ compiler. Your current compiler"
+			eerror "does not seem to support -std=c++11 option. Please upgrade your compiler"
+			eerror "to gcc-4.7 or an equivalent version supporting C++11."
+			die "Currently active compiler does not support -std=c++11"
+		fi
+		eend ${?}
+	fi
+}
+
+pkg_setup() {
+	pkg_pretend
+}
+
+src_unpack() {
+	default
+
+	if use clang; then
+		mv "${WORKDIR}"/cfe-${PV/_}.src "${S}"/tools/clang \
+			|| die "clang source directory move failed"
+		mv "${WORKDIR}"/compiler-rt-${PV/_}.src "${S}"/projects/compiler-rt \
+			|| die "compiler-rt source directory move failed"
+		mv "${WORKDIR}"/clang-tools-extra-${PV/_}.src "${S}"/tools/clang/tools/extra \
+			|| die "clang-tools-extra source directory move failed"
+	fi
+
+	if use lldb; then
+		mv "${WORKDIR}"/lldb-${PV/_}.src "${S}"/tools/lldb \
+			|| die "lldb source directory move failed"
+	fi
+}
+
+src_prepare() {
+	# Make ocaml warnings non-fatal, bug #537308
+	sed -e "/RUN/s/-warn-error A//" -i test/Bindings/OCaml/*ml  || die
+	# Fix libdir for ocaml bindings install, bug #559134
+	epatch "${FILESDIR}"/cmake/${P}-ocaml-multilib.patch
+	# Do not build/install ocaml docs with USE=-doc, bug #562008
+	epatch "${FILESDIR}"/cmake/${P}-ocaml-build_doc.patch
+
+	# Make it possible to override Sphinx HTML install dirs
+	# https://llvm.org/bugs/show_bug.cgi?id=23780
+	epatch "${FILESDIR}"/cmake/0002-cmake-Support-overriding-Sphinx-HTML-doc-install-dir.patch
+
+	# Prevent race conditions with parallel Sphinx runs
+	# https://llvm.org/bugs/show_bug.cgi?id=23781
+	epatch "${FILESDIR}"/cmake/0003-cmake-Add-an-ordering-dep-between-HTML-man-Sphinx-ta.patch
+
+	# Prevent installing libgtest
+	# https://llvm.org/bugs/show_bug.cgi?id=18341
+	epatch "${FILESDIR}"/cmake/0004-cmake-Do-not-install-libgtest.patch
+
+	# Fix llvm-config for shared linking and sane flags
+	# https://bugs.gentoo.org/show_bug.cgi?id=565358
+	epatch "${FILESDIR}"/llvm-3.7-llvm-config.patch
+
+	# Fix msan with newer kernels, #569894
+	epatch "${FILESDIR}"/llvm-3.7-msan-fix.patch
+
+	if use clang; then
+		# Automatically select active system GCC's libraries, bugs #406163 and #417913
+		epatch "${FILESDIR}"/clang-3.5-gentoo-runtime-gcc-detection-v3.patch
+
+		epatch "${FILESDIR}"/clang-3.6-gentoo-install.patch
+
+		sed -i -e "s^@EPREFIX@^${EPREFIX}^" \
+			tools/clang/tools/scan-build/scan-build || die
+
+		# Install clang runtime into /usr/lib/clang
+		# https://llvm.org/bugs/show_bug.cgi?id=23792
+		epatch "${FILESDIR}"/cmake/clang-0001-Install-clang-runtime-into-usr-lib-without-suffix.patch
+		epatch "${FILESDIR}"/cmake/compiler-rt-0001-cmake-Install-compiler-rt-into-usr-lib-without-suffi.patch
+
+		# Do not force -march flags on arm platforms
+		# https://bugs.gentoo.org/show_bug.cgi?id=562706
+		epatch "${FILESDIR}"/cmake/${P}-compiler_rt_arm_march_flags.patch
+
+		# Make it possible to override CLANG_LIBDIR_SUFFIX
+		# (that is used only to find LLVMgold.so)
+		# https://llvm.org/bugs/show_bug.cgi?id=23793
+		epatch "${FILESDIR}"/cmake/clang-0002-cmake-Make-CLANG_LIBDIR_SUFFIX-overridable.patch
+
+		pushd projects/compiler-rt >/dev/null || die
+
+		# Fix msan with newer kernels, compiler-rt part, #569894
+		epatch "${FILESDIR}"/compiler-rt-3.7-msan-fix.patch
+
+		# Fix WX sections, bug #421527
+		find lib/builtins -type f -name '*.S' -exec sed \
+			 -e '$a\\n#if defined(__linux__) && defined(__ELF__)\n.section .note.GNU-stack,"",%progbits\n#endif' \
+			 -i {} + || die
+
+		popd >/dev/null || die
+	fi
+
+	if use lldb; then
+		# Do not install dummy readline.so module from
+		# https://llvm.org/bugs/show_bug.cgi?id=18841
+		sed -e 's/add_subdirectory(readline)/#&/' \
+			-i tools/lldb/scripts/Python/modules/CMakeLists.txt || die
+
+		# Fix Python paths, bugs #562436 and #562438
+		epatch "${FILESDIR}"/${PN}-3.7-lldb_python.patch
+		sed -e "s/GENTOO_LIBDIR/$(get_libdir)/" \
+			-i tools/lldb/scripts/Python/finishSwigPythonLLDB.py || die
+
+		# Fix build with ncurses[tinfo], #560474
+		# http://llvm.org/viewvc/llvm-project?view=revision&revision=247842
+		epatch "${FILESDIR}"/cmake/${P}-lldb_tinfo.patch
+	fi
+
+	# User patches
+	epatch_user
+
+	python_setup
+
+	# Native libdir is used to hold LLVMgold.so
+	NATIVE_LIBDIR=$(get_libdir)
+}
+
+multilib_src_configure() {
+	local targets
+	if use multitarget; then
+		targets=all
+	else
+		targets='host;BPF;CppBackend'
+		use video_cards_radeon && targets+=';AMDGPU'
+	fi
+
+	local ffi_cflags ffi_ldflags
+	if use libffi; then
+		ffi_cflags=$(pkg-config --cflags-only-I libffi)
+		ffi_ldflags=$(pkg-config --libs-only-L libffi)
+	fi
+
+	local libdir=$(get_libdir)
+	local mycmakeargs=(
+		"${mycmakeargs[@]}"
+		-DLLVM_LIBDIR_SUFFIX=${libdir#lib}
+
+		-DBUILD_SHARED_LIBS=ON
+		-DLLVM_ENABLE_TIMESTAMPS=OFF
+		-DLLVM_TARGETS_TO_BUILD="${targets}"
+		-DLLVM_BUILD_TESTS=$(usex test)
+
+		-DLLVM_ENABLE_FFI=$(usex libffi)
+		-DLLVM_ENABLE_TERMINFO=$(usex ncurses)
+		-DLLVM_ENABLE_ASSERTIONS=$(usex debug)
+		-DLLVM_ENABLE_EH=ON
+		-DLLVM_ENABLE_RTTI=ON
+
+		-DWITH_POLLY=OFF # TODO
+
+		-DLLVM_HOST_TRIPLE="${CHOST}"
+
+		-DFFI_INCLUDE_DIR="${ffi_cflags#-I}"
+		-DFFI_LIBRARY_DIR="${ffi_ldflags#-L}"
+
+		-DHAVE_HISTEDIT_H=$(usex libedit)
+	)
+
+	if use clang; then
+		mycmakeargs+=(
+			-DCMAKE_DISABLE_FIND_PACKAGE_LibXml2=$(usex !xml)
+			# libgomp support fails to find headers without explicit -I
+			# furthermore, it provides only syntax checking
+			-DCLANG_DEFAULT_OPENMP_RUNTIME=libomp
+		)
+	fi
+
+	if use lldb; then
+		mycmakeargs+=(
+			-DLLDB_DISABLE_LIBEDIT=$(usex !libedit)
+			-DLLDB_DISABLE_CURSES=$(usex !ncurses)
+			-DLLDB_ENABLE_TERMINFO=$(usex ncurses)
+		)
+	fi
+
+	if ! multilib_is_native_abi || ! use ocaml; then
+		mycmakeargs+=(
+			-DOCAMLFIND=NO
+		)
+	fi
+#	Note: go bindings have no CMake rules at the moment
+#	but let's kill the check in case they are introduced
+#	if ! multilib_is_native_abi || ! use go; then
+		mycmakeargs+=(
+			-DGO_EXECUTABLE=GO_EXECUTABLE-NOTFOUND
+		)
+#	fi
+
+	if multilib_is_native_abi; then
+		mycmakeargs+=(
+			-DLLVM_BUILD_DOCS=$(usex doc)
+			-DLLVM_ENABLE_SPHINX=$(usex doc)
+			-DLLVM_ENABLE_DOXYGEN=OFF
+			-DLLVM_INSTALL_HTML="${EPREFIX}/usr/share/doc/${PF}/html"
+			-DSPHINX_WARNINGS_AS_ERRORS=OFF
+			-DLLVM_INSTALL_UTILS=ON
+		)
+
+		if use clang; then
+			mycmakeargs+=(
+				-DCLANG_INSTALL_HTML="${EPREFIX}/usr/share/doc/${PF}/clang"
+			)
+		fi
+
+		if use gold; then
+			mycmakeargs+=(
+				-DLLVM_BINUTILS_INCDIR="${EPREFIX}"/usr/include
+			)
+		fi
+
+		if use lldb; then
+			mycmakeargs+=(
+				-DLLDB_DISABLE_PYTHON=$(usex !python)
+			)
+		fi
+
+	else
+		if use clang; then
+			mycmakeargs+=(
+				# disable compiler-rt on non-native ABI because:
+				# 1. it fails to configure because of -m32
+				# 2. it is shared between ABIs so no point building
+				# it multiple times
+				-DLLVM_EXTERNAL_COMPILER_RT_BUILD=OFF
+				-DLLVM_EXTERNAL_CLANG_TOOLS_EXTRA_BUILD=OFF
+			)
+		fi
+		if use lldb; then
+			mycmakeargs+=(
+				# only run swig on native abi
+				-DLLDB_DISABLE_PYTHON=ON
+			)
+		fi
+	fi
+
+	if use clang; then
+		mycmakeargs+=(
+			-DCLANG_ENABLE_ARCMT=$(usex static-analyzer)
+			-DCLANG_ENABLE_STATIC_ANALYZER=$(usex static-analyzer)
+			-DCLANG_LIBDIR_SUFFIX="${NATIVE_LIBDIR#lib}"
+		)
+
+		# -- not needed when compiler-rt is built with host compiler --
+		# cmake passes host C*FLAGS to compiler-rt build
+		# which is performed using clang, so we need to filter out
+		# some flags clang does not support
+		# (if you know some more flags that don't work, let us know)
+		#filter-flags -msahf -frecord-gcc-switches
+	fi
+
+	cmake-utils_src_configure
+}
+
+multilib_src_compile() {
+	cmake-utils_src_compile
+	# TODO: not sure why this target is not correctly called
+	multilib_is_native_abi && use doc && use ocaml && cmake-utils_src_make docs/ocaml_doc
+
+	pax-mark m "${BUILD_DIR}"/bin/llvm-rtdyld
+	pax-mark m "${BUILD_DIR}"/bin/lli
+	pax-mark m "${BUILD_DIR}"/bin/lli-child-target
+
+	if use test; then
+		pax-mark m "${BUILD_DIR}"/unittests/ExecutionEngine/Orc/OrcJITTests
+		pax-mark m "${BUILD_DIR}"/unittests/ExecutionEngine/MCJIT/MCJITTests
+		pax-mark m "${BUILD_DIR}"/unittests/Support/SupportTests
+	fi
+}
+
+multilib_src_test() {
+	# respect TMPDIR!
+	local -x LIT_PRESERVES_TMP=1
+	local test_targets=( check )
+	# clang tests won't work on non-native ABI because we skip compiler-rt
+	multilib_is_native_abi && use clang && test_targets+=( check-clang )
+	cmake-utils_src_make "${test_targets[@]}"
+}
+
+src_install() {
+	local MULTILIB_CHOST_TOOLS=(
+		/usr/bin/llvm-config
+	)
+
+	local MULTILIB_WRAPPED_HEADERS=(
+		/usr/include/llvm/Config/config.h
+		/usr/include/llvm/Config/llvm-config.h
+	)
+
+	if use clang; then
+		# note: magic applied in multilib_src_install()!
+		CLANG_VERSION=${PV%.*}
+
+		MULTILIB_CHOST_TOOLS+=(
+			/usr/bin/clang
+			/usr/bin/clang++
+			/usr/bin/clang-cl
+			/usr/bin/clang-${CLANG_VERSION}
+			/usr/bin/clang++-${CLANG_VERSION}
+			/usr/bin/clang-cl-${CLANG_VERSION}
+		)
+
+		MULTILIB_WRAPPED_HEADERS+=(
+			/usr/include/clang/Config/config.h
+		)
+	fi
+
+	multilib-minimal_src_install
+}
+
+multilib_src_install() {
+	cmake-utils_src_install
+
+	if multilib_is_native_abi; then
+		# Install man pages.
+		use doc || doman "${WORKDIR}"/${P}-manpages/*.1
+
+		# Symlink the gold plugin.
+		if use gold; then
+			dodir "/usr/${CHOST}/binutils-bin/lib/bfd-plugins"
+			dosym "../../../../$(get_libdir)/LLVMgold.so" \
+				"/usr/${CHOST}/binutils-bin/lib/bfd-plugins/LLVMgold.so"
+		fi
+	fi
+
+	# apply CHOST and CLANG_VERSION to clang executables
+	# they're statically linked so we don't have to worry about the lib
+	if use clang; then
+		local clang_tools=( clang clang++ clang-cl )
+		local i
+
+		# cmake gives us:
+		# - clang-X.Y
+		# - clang -> clang-X.Y
+		# - clang++, clang-cl -> clang
+		# we want to have:
+		# - clang-X.Y
+		# - clang++-X.Y, clang-cl-X.Y -> clang-X.Y
+		# - clang, clang++, clang-cl -> clang*-X.Y
+		# so we need to fix the two tools
+		for i in "${clang_tools[@]:1}"; do
+			rm "${ED%/}/usr/bin/${i}" || die
+			dosym "clang-${CLANG_VERSION}" "/usr/bin/${i}-${CLANG_VERSION}"
+			dosym "${i}-${CLANG_VERSION}" "/usr/bin/${i}"
+		done
+
+		# now prepend ${CHOST} and let the multilib-build.eclass symlink it
+		if ! multilib_is_native_abi; then
+			# non-native? let's replace it with a simple wrapper
+			for i in "${clang_tools[@]}"; do
+				rm "${ED%/}/usr/bin/${i}-${CLANG_VERSION}" || die
+				cat > "${T}"/wrapper.tmp <<-_EOF_
+					#!${EPREFIX}/bin/sh
+					exec "${i}-${CLANG_VERSION}" $(get_abi_CFLAGS) "\${@}"
+				_EOF_
+				newbin "${T}"/wrapper.tmp "${i}-${CLANG_VERSION}"
+			done
+		fi
+	fi
+}
+
+multilib_src_install_all() {
+	insinto /usr/share/vim/vimfiles
+	doins -r utils/vim/*/.
+	# some users may find it useful
+	dodoc utils/vim/vimrc
+
+	if use clang; then
+		pushd tools/clang >/dev/null || die
+
+		if use static-analyzer ; then
+			pushd tools/scan-build >/dev/null || die
+
+			dobin ccc-analyzer scan-build
+			dosym ccc-analyzer /usr/bin/c++-analyzer
+			doman scan-build.1
+
+			insinto /usr/share/llvm
+			doins scanview.css sorttable.js
+
+			popd >/dev/null || die
+		fi
+
+		if use static-analyzer ; then
+			pushd tools/scan-view >/dev/null || die
+
+			python_doscript scan-view
+
+			touch __init__.py || die
+			python_moduleinto clang
+			python_domodule *.py Resources
+
+			popd >/dev/null || die
+		fi
+
+		if use python ; then
+			pushd bindings/python/clang >/dev/null || die
+
+			python_moduleinto clang
+			python_domodule *.py
+
+			popd >/dev/null || die
+		fi
+
+		# AddressSanitizer symbolizer (currently separate)
+		dobin "${S}"/projects/compiler-rt/lib/asan/scripts/asan_symbolize.py
+
+		popd >/dev/null || die
+
+		python_fix_shebang "${ED}"
+		if use lldb && use python; then
+			python_optimize
+		fi
+	fi
+}
+
+pkg_postinst() {
+	if use clang; then
+		elog "To enable OpenMP support in clang, install sys-libs/libomp"
+		elog "and use the '-fopenmp=libomp' command line option"
+	fi
+}