[gentoo-commits] repo/gentoo:master commit in: llvm-runtimes/libcxx/

["Michał Górny" <mgorny@gentoo.org>]

commit:     4b9aa358421f60057eb35ba5ab5c73945d7fca8b
Author:     Michal Rostecki <vadorovsky <AT> protonmail <DOT> com>
AuthorDate: Mon Dec  2 14:04:51 2024 +0000
Commit:     Michał Górny <mgorny <AT> gentoo <DOT> org>
CommitDate: Mon Mar 17 06:21:36 2025 +0000
URL:        https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=4b9aa358

sys-libs/libcxx: Support cross build

Inherit the `crossdev` eclass and use a cross sysroot when a custom
target is specified. That allows to bootstrap libcxx with crossdev.

Extend the compiler test with the case when the (cross) toolchain has
a runtime, but doesn't have stdlib yet (because it's about to be built).
In such case, a build with default arguments fails, but a build with
`-nostdlib` succeeds. libc++ doesn't need stdlib to build, so that's
fine.

Signed-off-by: Michal Rostecki <vadorovsky <AT> protonmail.com>
Signed-off-by: Michał Górny <mgorny <AT> gentoo.org>

 ...ibcxx-20.1.0.ebuild => libcxx-19.1.7-r1.ebuild} | 59 ++++++++++++++--------
 llvm-runtimes/libcxx/libcxx-20.1.0.ebuild          | 50 +++++++++++++-----
 llvm-runtimes/libcxx/libcxx-21.0.0.9999.ebuild     | 50 +++++++++++++-----
 3 files changed, 112 insertions(+), 47 deletions(-)

diff --git a/llvm-runtimes/libcxx/libcxx-20.1.0.ebuild b/llvm-runtimes/libcxx/libcxx-19.1.7-r1.ebuild
similarity index 74%
copy from llvm-runtimes/libcxx/libcxx-20.1.0.ebuild
copy to llvm-runtimes/libcxx/libcxx-19.1.7-r1.ebuild
index 75a626f221f8..08e54cd9b566 100644
--- a/llvm-runtimes/libcxx/libcxx-20.1.0.ebuild
+++ b/llvm-runtimes/libcxx/libcxx-19.1.7-r1.ebuild
@@ -4,8 +4,8 @@
 EAPI=8
 
 PYTHON_COMPAT=( python3_{10..13} )
-inherit cmake-multilib flag-o-matic llvm.org llvm-utils python-any-r1
-inherit toolchain-funcs
+inherit cmake-multilib crossdev flag-o-matic llvm.org llvm-utils
+inherit python-any-r1 toolchain-funcs
 
 DESCRIPTION="New implementation of the C++ standard library, targeting C++11"
 HOMEPAGE="https://libcxx.llvm.org/"
@@ -40,9 +40,7 @@ BDEPEND="
 	)
 "
 
-LLVM_COMPONENTS=(
-	runtimes libcxx{,abi} libc llvm/{cmake,utils/llvm-lit} cmake
-)
+LLVM_COMPONENTS=( runtimes libcxx{,abi} llvm/{cmake,utils/llvm-lit} cmake )
 llvm.org_set_globals
 
 python_check_deps() {
@@ -69,12 +67,15 @@ test_compiler() {
 src_configure() {
 	llvm_prepend_path "${LLVM_MAJOR}"
 
+	local install_prefix=${EPREFIX}
+	target_is_not_host && install_prefix+=/usr/${CTARGET}
+
 	# note: we need to do this before multilib kicks in since it will
 	# alter the CHOST
 	local cxxabi cxxabi_incs
 	if use libcxxabi; then
 		cxxabi=system-libcxxabi
-		cxxabi_incs="${EPREFIX}/usr/include/c++/v1"
+		cxxabi_incs="${install_prefix}/usr/include/c++/v1"
 	else
 		local gcc_inc="${EPREFIX}/usr/lib/gcc/${CHOST}/$(gcc-fullversion)/include/g++-v$(gcc-major-version)"
 		cxxabi=libsupc++
@@ -86,8 +87,8 @@ src_configure() {
 
 multilib_src_configure() {
 	if use clang; then
-		local -x CC=${CHOST}-clang
-		local -x CXX=${CHOST}-clang++
+		local -x CC=${CTARGET}-clang
+		local -x CXX=${CTARGET}-clang++
 		strip-unsupported-flags
 	fi
 
@@ -95,18 +96,29 @@ multilib_src_configure() {
 	local use_compiler_rt=OFF
 	[[ $(tc-get-c-rtlib) == compiler-rt ]] && use_compiler_rt=ON
 
-	# bootstrap: cmake is unhappy if compiler can't link to stdlib
-	local nolib_flags=( -nodefaultlibs -lc )
-	if ! test_compiler; then
-		if test_compiler "${nolib_flags[@]}"; then
-			local -x LDFLAGS="${LDFLAGS} ${nolib_flags[*]}"
-			ewarn "${CXX} seems to lack runtime, trying with ${nolib_flags[*]}"
+	# Scenarios to consider:
+	#
+	# 1. Compiler test works with the default flags.
+	# 2. There is a runtime library, but no stdlib. In that case, leave the
+	#    LDFLAGS untouched, since there is no self-dependency in libc++.
+	# 3. There is no runtime library nor stdlib. In that case, overwrite the
+	#    LDFLAGS.
+	local nostdlib_flags=( -nostdlib --rtlib=compiler-rt -lc )
+	local nort_flags=( -nodefaultlibs -lc )
+	if ! test_compiler && ! test_compiler "${nostdlib_flags[@]}"; then
+		if test_compiler "${nort_flags[@]}"; then
+			local -x LDFLAGS="${LDFLAGS} ${nort_flags[*]}"
+			ewarn "${CXX} seems to lack runtime, trying with ${nort_flags[*]}"
 		fi
 	fi
 
+	local install_prefix=${EPREFIX}
+	target_is_not_host && install_prefix+=/usr/${CTARGET}
+
 	local libdir=$(get_libdir)
 	local mycmakeargs=(
-		-DCMAKE_CXX_COMPILER_TARGET="${CHOST}"
+		-DCMAKE_CXX_COMPILER_TARGET="${CTARGET}"
+		-DCMAKE_INSTALL_PREFIX="${install_prefix}/usr"
 		-DPython3_EXECUTABLE="${PYTHON}"
 		-DLLVM_ENABLE_RUNTIMES=libcxx
 		-DLLVM_INCLUDE_TESTS=OFF
@@ -126,7 +138,16 @@ multilib_src_configure() {
 		# this is broken with standalone builds, and also meaningless
 		-DLIBCXXABI_USE_LLVM_UNWINDER=OFF
 	)
-
+	if is_crosspkg; then
+		# Needed to target built libc headers
+		local -x CFLAGS="${CFLAGS} -isystem ${ESYSROOT}/usr/${CTARGET}/usr/include"
+		mycmakeargs+=(
+			# Without this, the compiler will compile a test program
+			# and fail due to no builtins.
+			-DCMAKE_C_COMPILER_WORKS=1
+			-DCMAKE_CXX_COMPILER_WORKS=1
+		)
+	fi
 	if use test; then
 		mycmakeargs+=(
 			-DLLVM_EXTERNAL_LIT="${EPREFIX}/usr/bin/lit"
@@ -147,11 +168,6 @@ multilib_src_compile() {
 
 multilib_src_test() {
 	local -x LIT_PRESERVES_TMP=1
-	cmake_build install-cxx-test-suite-prefix
-	cp "${BUILD_DIR}"/{lib,libcxx/test-suite-install/$(get_libdir)}/libc++_shared.so || die
-	if use static-libs; then
-		cp "${BUILD_DIR}"/{lib,libcxx/test-suite-install/$(get_libdir)}/libc++_static.a || die
-	fi
 	cmake_build check-cxx
 }
 
@@ -160,6 +176,7 @@ multilib_src_install() {
 	# since we've replaced libc++.{a,so} with ldscripts, now we have to
 	# install the extra symlinks
 	if [[ ${CHOST} != *-darwin* ]] ; then
+		target_is_not_host && into /usr/${CTARGET}
 		dolib.so lib/libc++_shared.so
 		use static-libs && dolib.a lib/libc++_static.a
 	fi

diff --git a/llvm-runtimes/libcxx/libcxx-20.1.0.ebuild b/llvm-runtimes/libcxx/libcxx-20.1.0.ebuild
index 75a626f221f8..3b7c0a5e8bfb 100644
--- a/llvm-runtimes/libcxx/libcxx-20.1.0.ebuild
+++ b/llvm-runtimes/libcxx/libcxx-20.1.0.ebuild
@@ -4,8 +4,8 @@
 EAPI=8
 
 PYTHON_COMPAT=( python3_{10..13} )
-inherit cmake-multilib flag-o-matic llvm.org llvm-utils python-any-r1
-inherit toolchain-funcs
+inherit cmake-multilib crossdev flag-o-matic llvm.org llvm-utils
+inherit python-any-r1 toolchain-funcs
 
 DESCRIPTION="New implementation of the C++ standard library, targeting C++11"
 HOMEPAGE="https://libcxx.llvm.org/"
@@ -69,12 +69,15 @@ test_compiler() {
 src_configure() {
 	llvm_prepend_path "${LLVM_MAJOR}"
 
+	local install_prefix=${EPREFIX}
+	target_is_not_host && install_prefix+=/usr/${CTARGET}
+
 	# note: we need to do this before multilib kicks in since it will
 	# alter the CHOST
 	local cxxabi cxxabi_incs
 	if use libcxxabi; then
 		cxxabi=system-libcxxabi
-		cxxabi_incs="${EPREFIX}/usr/include/c++/v1"
+		cxxabi_incs="${install_prefix}/usr/include/c++/v1"
 	else
 		local gcc_inc="${EPREFIX}/usr/lib/gcc/${CHOST}/$(gcc-fullversion)/include/g++-v$(gcc-major-version)"
 		cxxabi=libsupc++
@@ -86,8 +89,8 @@ src_configure() {
 
 multilib_src_configure() {
 	if use clang; then
-		local -x CC=${CHOST}-clang
-		local -x CXX=${CHOST}-clang++
+		local -x CC=${CTARGET}-clang
+		local -x CXX=${CTARGET}-clang++
 		strip-unsupported-flags
 	fi
 
@@ -95,18 +98,29 @@ multilib_src_configure() {
 	local use_compiler_rt=OFF
 	[[ $(tc-get-c-rtlib) == compiler-rt ]] && use_compiler_rt=ON
 
-	# bootstrap: cmake is unhappy if compiler can't link to stdlib
-	local nolib_flags=( -nodefaultlibs -lc )
-	if ! test_compiler; then
-		if test_compiler "${nolib_flags[@]}"; then
-			local -x LDFLAGS="${LDFLAGS} ${nolib_flags[*]}"
-			ewarn "${CXX} seems to lack runtime, trying with ${nolib_flags[*]}"
+	# Scenarios to consider:
+	#
+	# 1. Compiler test works with the default flags.
+	# 2. There is a runtime library, but no stdlib. In that case, leave the
+	#    LDFLAGS untouched, since there is no self-dependency in libc++.
+	# 3. There is no runtime library nor stdlib. In that case, overwrite the
+	#    LDFLAGS.
+	local nostdlib_flags=( -nostdlib --rtlib=compiler-rt -lc )
+	local nort_flags=( -nodefaultlibs -lc )
+	if ! test_compiler && ! test_compiler "${nostdlib_flags[@]}"; then
+		if test_compiler "${nort_flags[@]}"; then
+			local -x LDFLAGS="${LDFLAGS} ${nort_flags[*]}"
+			ewarn "${CXX} seems to lack runtime, trying with ${nort_flags[*]}"
 		fi
 	fi
 
+	local install_prefix=${EPREFIX}
+	target_is_not_host && install_prefix+=/usr/${CTARGET}
+
 	local libdir=$(get_libdir)
 	local mycmakeargs=(
-		-DCMAKE_CXX_COMPILER_TARGET="${CHOST}"
+		-DCMAKE_CXX_COMPILER_TARGET="${CTARGET}"
+		-DCMAKE_INSTALL_PREFIX="${install_prefix}/usr"
 		-DPython3_EXECUTABLE="${PYTHON}"
 		-DLLVM_ENABLE_RUNTIMES=libcxx
 		-DLLVM_INCLUDE_TESTS=OFF
@@ -126,7 +140,16 @@ multilib_src_configure() {
 		# this is broken with standalone builds, and also meaningless
 		-DLIBCXXABI_USE_LLVM_UNWINDER=OFF
 	)
-
+	if is_crosspkg; then
+		# Needed to target built libc headers
+		local -x CFLAGS="${CFLAGS} -isystem ${ESYSROOT}/usr/${CTARGET}/usr/include"
+		mycmakeargs+=(
+			# Without this, the compiler will compile a test program
+			# and fail due to no builtins.
+			-DCMAKE_C_COMPILER_WORKS=1
+			-DCMAKE_CXX_COMPILER_WORKS=1
+		)
+	fi
 	if use test; then
 		mycmakeargs+=(
 			-DLLVM_EXTERNAL_LIT="${EPREFIX}/usr/bin/lit"
@@ -160,6 +183,7 @@ multilib_src_install() {
 	# since we've replaced libc++.{a,so} with ldscripts, now we have to
 	# install the extra symlinks
 	if [[ ${CHOST} != *-darwin* ]] ; then
+		target_is_not_host && into /usr/${CTARGET}
 		dolib.so lib/libc++_shared.so
 		use static-libs && dolib.a lib/libc++_static.a
 	fi

diff --git a/llvm-runtimes/libcxx/libcxx-21.0.0.9999.ebuild b/llvm-runtimes/libcxx/libcxx-21.0.0.9999.ebuild
index f6f57e2287bd..d3a183fb38cc 100644
--- a/llvm-runtimes/libcxx/libcxx-21.0.0.9999.ebuild
+++ b/llvm-runtimes/libcxx/libcxx-21.0.0.9999.ebuild
@@ -4,8 +4,8 @@
 EAPI=8
 
 PYTHON_COMPAT=( python3_{10..13} )
-inherit cmake-multilib flag-o-matic llvm.org llvm-utils python-any-r1
-inherit toolchain-funcs
+inherit cmake-multilib crossdev flag-o-matic llvm.org llvm-utils
+inherit python-any-r1 toolchain-funcs
 
 DESCRIPTION="New implementation of the C++ standard library, targeting C++11"
 HOMEPAGE="https://libcxx.llvm.org/"
@@ -68,12 +68,15 @@ test_compiler() {
 src_configure() {
 	llvm_prepend_path "${LLVM_MAJOR}"
 
+	local install_prefix=${EPREFIX}
+	target_is_not_host && install_prefix+=/usr/${CTARGET}
+
 	# note: we need to do this before multilib kicks in since it will
 	# alter the CHOST
 	local cxxabi cxxabi_incs
 	if use libcxxabi; then
 		cxxabi=system-libcxxabi
-		cxxabi_incs="${EPREFIX}/usr/include/c++/v1"
+		cxxabi_incs="${install_prefix}/usr/include/c++/v1"
 	else
 		local gcc_inc="${EPREFIX}/usr/lib/gcc/${CHOST}/$(gcc-fullversion)/include/g++-v$(gcc-major-version)"
 		cxxabi=libsupc++
@@ -85,8 +88,8 @@ src_configure() {
 
 multilib_src_configure() {
 	if use clang; then
-		local -x CC=${CHOST}-clang
-		local -x CXX=${CHOST}-clang++
+		local -x CC=${CTARGET}-clang
+		local -x CXX=${CTARGET}-clang++
 		strip-unsupported-flags
 	fi
 
@@ -94,18 +97,29 @@ multilib_src_configure() {
 	local use_compiler_rt=OFF
 	[[ $(tc-get-c-rtlib) == compiler-rt ]] && use_compiler_rt=ON
 
-	# bootstrap: cmake is unhappy if compiler can't link to stdlib
-	local nolib_flags=( -nodefaultlibs -lc )
-	if ! test_compiler; then
-		if test_compiler "${nolib_flags[@]}"; then
-			local -x LDFLAGS="${LDFLAGS} ${nolib_flags[*]}"
-			ewarn "${CXX} seems to lack runtime, trying with ${nolib_flags[*]}"
+	# Scenarios to consider:
+	#
+	# 1. Compiler test works with the default flags.
+	# 2. There is a runtime library, but no stdlib. In that case, leave the
+	#    LDFLAGS untouched, since there is no self-dependency in libc++.
+	# 3. There is no runtime library nor stdlib. In that case, overwrite the
+	#    LDFLAGS.
+	local nostdlib_flags=( -nostdlib --rtlib=compiler-rt -lc )
+	local nort_flags=( -nodefaultlibs -lc )
+	if ! test_compiler && ! test_compiler "${nostdlib_flags[@]}"; then
+		if test_compiler "${nort_flags[@]}"; then
+			local -x LDFLAGS="${LDFLAGS} ${nort_flags[*]}"
+			ewarn "${CXX} seems to lack runtime, trying with ${nort_flags[*]}"
 		fi
 	fi
 
+	local install_prefix=${EPREFIX}
+	target_is_not_host && install_prefix+=/usr/${CTARGET}
+
 	local libdir=$(get_libdir)
 	local mycmakeargs=(
-		-DCMAKE_CXX_COMPILER_TARGET="${CHOST}"
+		-DCMAKE_CXX_COMPILER_TARGET="${CTARGET}"
+		-DCMAKE_INSTALL_PREFIX="${install_prefix}/usr"
 		-DPython3_EXECUTABLE="${PYTHON}"
 		-DLLVM_ENABLE_RUNTIMES=libcxx
 		-DLLVM_INCLUDE_TESTS=OFF
@@ -125,7 +139,16 @@ multilib_src_configure() {
 		# this is broken with standalone builds, and also meaningless
 		-DLIBCXXABI_USE_LLVM_UNWINDER=OFF
 	)
-
+	if is_crosspkg; then
+		# Needed to target built libc headers
+		local -x CFLAGS="${CFLAGS} -isystem ${ESYSROOT}/usr/${CTARGET}/usr/include"
+		mycmakeargs+=(
+			# Without this, the compiler will compile a test program
+			# and fail due to no builtins.
+			-DCMAKE_C_COMPILER_WORKS=1
+			-DCMAKE_CXX_COMPILER_WORKS=1
+		)
+	fi
 	if use test; then
 		mycmakeargs+=(
 			-DLLVM_EXTERNAL_LIT="${EPREFIX}/usr/bin/lit"
@@ -159,6 +182,7 @@ multilib_src_install() {
 	# since we've replaced libc++.{a,so} with ldscripts, now we have to
 	# install the extra symlinks
 	if [[ ${CHOST} != *-darwin* ]] ; then
+		target_is_not_host && into /usr/${CTARGET}
 		dolib.so lib/libc++_shared.so
 		use static-libs && dolib.a lib/libc++_static.a
 	fi