Merge updates from master

eclass/tests/toolchain-funcs.sh

@@ -60,20 +60,22 @@ tbegin "tc-ld-is-gold (ld=bfd cc=bfd)"
 LD=ld.bfd LDFLAGS=-fuse-ld=bfd tc-ld-is-gold && ret=1 || ret=0
 tend ${ret}
 
-tbegin "tc-ld-is-gold (ld=gold cc=default)"
-LD=ld.gold tc-ld-is-gold
-ret=$?
-tend ${ret}
+if type -P ld.gold &>/dev/null; then
+	tbegin "tc-ld-is-gold (ld=gold cc=default)"
+	LD=ld.gold tc-ld-is-gold
+	ret=$?
+	tend ${ret}
 
-tbegin "tc-ld-is-gold (ld=gold cc=bfd)"
-LD=ld.gold LDFLAGS=-fuse-ld=bfd tc-ld-is-gold
-ret=$?
-tend ${ret}
+	tbegin "tc-ld-is-gold (ld=gold cc=bfd)"
+	LD=ld.gold LDFLAGS=-fuse-ld=bfd tc-ld-is-gold
+	ret=$?
+	tend ${ret}
 
-tbegin "tc-ld-is-gold (ld=bfd cc=gold)"
-LD=ld.bfd LDFLAGS=-fuse-ld=gold tc-ld-is-gold
-ret=$?
-tend ${ret}
+	tbegin "tc-ld-is-gold (ld=bfd cc=gold)"
+	LD=ld.bfd LDFLAGS=-fuse-ld=gold tc-ld-is-gold
+	ret=$?
+	tend ${ret}
+fi
 
 #
 # TEST: tc-ld-disable-gold
@@ -87,23 +89,25 @@ tc-ld-disable-gold
 )
 tend $?
 
-tbegin "tc-ld-disable-gold (ld=gold)"
-(
-export LD=ld.gold LDFLAGS=
-ewarn() { :; }
-tc-ld-disable-gold
-[[ ${LD} == "ld.bfd" || ${LDFLAGS} == *"-fuse-ld=bfd"* ]]
-)
-tend $?
+if type -P ld.gold &>/dev/null; then
+	tbegin "tc-ld-disable-gold (ld=gold)"
+	(
+	export LD=ld.gold LDFLAGS=
+	ewarn() { :; }
+	tc-ld-disable-gold
+	[[ ${LD} == "ld.bfd" || ${LDFLAGS} == *"-fuse-ld=bfd"* ]]
+	)
+	tend $?
 
-tbegin "tc-ld-disable-gold (cc=gold)"
-(
-export LD= LDFLAGS="-fuse-ld=gold"
-ewarn() { :; }
-tc-ld-disable-gold
-[[ ${LD} == *"/ld.bfd" || ${LDFLAGS} == "-fuse-ld=gold -fuse-ld=bfd" ]]
-)
-tend $?
+	tbegin "tc-ld-disable-gold (cc=gold)"
+	(
+	export LD= LDFLAGS="-fuse-ld=gold"
+	ewarn() { :; }
+	tc-ld-disable-gold
+	[[ ${LD} == *"/ld.bfd" || ${LDFLAGS} == "-fuse-ld=gold -fuse-ld=bfd" ]]
+	)
+	tend $?
+fi
 
 unset CPP
 
@@ -198,4 +202,36 @@ for compiler in gcc clang not-really-a-compiler; do
 	fi
 done
 
+if type -P gcc &>/dev/null; then
+	tbegin "tc-get-cxx-stdlib (gcc)"
+	[[ $(CXX=g++ tc-get-cxx-stdlib) == libstdc++ ]]
+	tend $?
+
+	tbegin "tc-get-c-rtlib (gcc)"
+	[[ $(CC=gcc tc-get-c-rtlib) == libgcc ]]
+	tend $?
+fi
+
+if type -P clang &>/dev/null; then
+	for stdlib in libc++ libstdc++; do
+		if clang++ -stdlib=${stdlib} -x c++ -E -P - &>/dev/null \
+			<<<'#include <ciso646>'
+		then
+			tbegin "tc-get-cxx-stdlib (clang, ${stdlib})"
+			[[ $(CXX=clang++ CXXFLAGS="-stdlib=${stdlib}" tc-get-cxx-stdlib) == ${stdlib} ]]
+			tend $?
+		fi
+	done
+
+	tbegin "tc-get-cxx-stdlib (clang, invalid)"
+	! CXX=clang++ CXXFLAGS="-stdlib=invalid" tc-get-cxx-stdlib
+	tend $?
+
+	for rtlib in compiler-rt libgcc; do
+		tbegin "tc-get-c-rtlib (clang, ${rtlib})"
+		[[ $(CC=clang CFLAGS="--rtlib=${rtlib}" tc-get-c-rtlib) == ${rtlib} ]]
+		tend $?
+	done
+fi
+
 texit

eclass/toolchain-funcs.eclass

@@ -1173,4 +1173,68 @@ gen_usr_ldscript() {
 	done
 }
 
+# @FUNCTION: tc-get-cxx-stdlib
+# @DESCRIPTION:
+# Attempt to identify the C++ standard library used by the compiler.
+# If the library is identified, the function returns 0 and prints one
+# of the following:
+#
+# - ``libc++`` for ``sys-libs/libcxx``
+# - ``libstdc++`` for ``sys-devel/gcc``'s libstdc++
+#
+# If the library is not recognized, the function returns 1.
+tc-get-cxx-stdlib() {
+	local code='#include <ciso646>
+
+#if defined(_LIBCPP_VERSION)
+	HAVE_LIBCXX
+#elif defined(__GLIBCXX__)
+	HAVE_LIBSTDCPP
+#endif
+'
+	local res=$(
+		$(tc-getCXX) ${CXXFLAGS} ${CPPFLAGS} -x c++ -E -P - \
+			<<<"${code}" 2>/dev/null
+	)
+
+	case ${res} in
+		*HAVE_LIBCXX*)
+			echo libc++;;
+		*HAVE_LIBSTDCPP*)
+			echo libstdc++;;
+		*)
+			return 1;;
+	esac
+
+	return 0
+}
+
+# @FUNCTION: tc-get-c-rtlib
+# @DESCRIPTION:
+# Attempt to identify the runtime used by the C/C++ compiler.
+# If the runtime is identifed, the function returns 0 and prints one
+# of the following:
+#
+# - ``compiler-rt`` for ``sys-libs/compiler-rt``
+# - ``libgcc`` for ``sys-devel/gcc``'s libgcc
+#
+# If the runtime is not recognized, the function returns 1.
+tc-get-c-rtlib() {
+	local res=$(
+		$(tc-getCC) ${CFLAGS} ${CPPFLAGS} ${LDFLAGS} \
+			-print-libgcc-file-name 2>/dev/null
+	)
+
+	case ${res} in
+		*libclang_rt*)
+			echo compiler-rt;;
+		*libgcc*)
+			echo libgcc;;
+		*)
+			return 1;;
+	esac
+
+	return 0
+}
+
 fi

sys-devel/llvm/llvm-13.0.1.ebuild

@@ -174,18 +174,6 @@ src_prepare() {
 	llvm.org_src_prepare
 }
 
-# Is LLVM being linked against libc++?
-is_libcxx_linked() {
-	local code='#include <ciso646>
-#if defined(_LIBCPP_VERSION)
-	HAVE_LIBCXX
-#endif
-'
-	local out=$($(tc-getCXX) ${CXXFLAGS} ${CPPFLAGS} -x c++ -E -P - <<<"${code}") || return 1
-
-	[[ ${out} == *HAVE_LIBCXX* ]]
-}
-
 get_distribution_components() {
 	local sep=${1-;}
 
@@ -367,7 +355,7 @@ multilib_src_configure() {
 		-DOCAMLFIND=NO
 	)
 
-	if is_libcxx_linked; then
+	if [[ $(tc-get-cxx-stdlib) == libc++ ]]; then
 		# Smart hack: alter version suffix -> SOVERSION when linking
 		# against libc++. This way we won't end up mixing LLVM libc++
 		# libraries with libstdc++ clang, and the other way around.

sys-devel/llvm/llvm-14.0.6-r2.ebuild

@@ -186,18 +186,6 @@ src_prepare() {
 	rm test/Other/ChangePrinters/DotCfg/print-changed-dot-cfg.ll || die
 }
 
-# Is LLVM being linked against libc++?
-is_libcxx_linked() {
-	local code='#include <ciso646>
-#if defined(_LIBCPP_VERSION)
-	HAVE_LIBCXX
-#endif
-'
-	local out=$($(tc-getCXX) ${CXXFLAGS} ${CPPFLAGS} -x c++ -E -P - <<<"${code}") || return 1
-
-	[[ ${out} == *HAVE_LIBCXX* ]]
-}
-
 get_distribution_components() {
 	local sep=${1-;}
 
@@ -381,7 +369,7 @@ multilib_src_configure() {
 		-DOCAMLFIND=NO
 	)
 
-	if is_libcxx_linked; then
+	if [[ $(tc-get-cxx-stdlib) == libc++ ]]; then
 		# Smart hack: alter version suffix -> SOVERSION when linking
 		# against libc++. This way we won't end up mixing LLVM libc++
 		# libraries with libstdc++ clang, and the other way around.

sys-devel/llvm/llvm-15.0.2.ebuild

@@ -180,18 +180,6 @@ src_prepare() {
 	llvm.org_src_prepare
 }
 
-# Is LLVM being linked against libc++?
-is_libcxx_linked() {
-	local code='#include <ciso646>
-#if defined(_LIBCPP_VERSION)
-	HAVE_LIBCXX
-#endif
-'
-	local out=$($(tc-getCXX) ${CXXFLAGS} ${CPPFLAGS} -x c++ -E -P - <<<"${code}") || return 1
-
-	[[ ${out} == *HAVE_LIBCXX* ]]
-}
-
 get_distribution_components() {
 	local sep=${1-;}
 
@@ -379,7 +367,7 @@ multilib_src_configure() {
 		-DOCAMLFIND=NO
 	)
 
-	if is_libcxx_linked; then
+	if [[ $(tc-get-cxx-stdlib) == libc++ ]]; then
 		# Smart hack: alter version suffix -> SOVERSION when linking
 		# against libc++. This way we won't end up mixing LLVM libc++
 		# libraries with libstdc++ clang, and the other way around.

sys-devel/llvm/llvm-15.0.3.9999.ebuild

@@ -180,18 +180,6 @@ src_prepare() {
 	llvm.org_src_prepare
 }
 
-# Is LLVM being linked against libc++?
-is_libcxx_linked() {
-	local code='#include <ciso646>
-#if defined(_LIBCPP_VERSION)
-	HAVE_LIBCXX
-#endif
-'
-	local out=$($(tc-getCXX) ${CXXFLAGS} ${CPPFLAGS} -x c++ -E -P - <<<"${code}") || return 1
-
-	[[ ${out} == *HAVE_LIBCXX* ]]
-}
-
 get_distribution_components() {
 	local sep=${1-;}
 
@@ -379,7 +367,7 @@ multilib_src_configure() {
 		-DOCAMLFIND=NO
 	)
 
-	if is_libcxx_linked; then
+	if [[ $(tc-get-cxx-stdlib) == libc++ ]]; then
 		# Smart hack: alter version suffix -> SOVERSION when linking
 		# against libc++. This way we won't end up mixing LLVM libc++
 		# libraries with libstdc++ clang, and the other way around.

sys-devel/llvm/llvm-16.0.0.9999.ebuild

@@ -184,18 +184,6 @@ src_prepare() {
 	llvm.org_src_prepare
 }
 
-# Is LLVM being linked against libc++?
-is_libcxx_linked() {
-	local code='#include <ciso646>
-#if defined(_LIBCPP_VERSION)
-	HAVE_LIBCXX
-#endif
-'
-	local out=$($(tc-getCXX) ${CXXFLAGS} ${CPPFLAGS} -x c++ -E -P - <<<"${code}") || return 1
-
-	[[ ${out} == *HAVE_LIBCXX* ]]
-}
-
 get_distribution_components() {
 	local sep=${1-;}
 
@@ -391,7 +379,7 @@ multilib_src_configure() {
 		# the commit id in the SOVERSION to contain the breakage
 		suffix+="git${EGIT_VERSION::8}"
 	fi
-	if is_libcxx_linked; then
+	if [[ $(tc-get-cxx-stdlib) == libc++ ]]; then
 		# Smart hack: alter version suffix -> SOVERSION when linking
 		# against libc++. This way we won't end up mixing LLVM libc++
 		# libraries with libstdc++ clang, and the other way around.

sys-devel/llvm/llvm-16.0.0_pre20221006.ebuild

@@ -184,18 +184,6 @@ src_prepare() {
 	llvm.org_src_prepare
 }
 
-# Is LLVM being linked against libc++?
-is_libcxx_linked() {
-	local code='#include <ciso646>
-#if defined(_LIBCPP_VERSION)
-	HAVE_LIBCXX
-#endif
-'
-	local out=$($(tc-getCXX) ${CXXFLAGS} ${CPPFLAGS} -x c++ -E -P - <<<"${code}") || return 1
-
-	[[ ${out} == *HAVE_LIBCXX* ]]
-}
-
 get_distribution_components() {
 	local sep=${1-;}
 
@@ -391,7 +379,7 @@ multilib_src_configure() {
 		# the commit id in the SOVERSION to contain the breakage
 		suffix+="git${EGIT_VERSION::8}"
 	fi
-	if is_libcxx_linked; then
+	if [[ $(tc-get-cxx-stdlib) == libc++ ]]; then
 		# Smart hack: alter version suffix -> SOVERSION when linking
 		# against libc++. This way we won't end up mixing LLVM libc++
 		# libraries with libstdc++ clang, and the other way around.

sys-devel/llvm/llvm-16.0.0_pre20221010.ebuild

@@ -184,18 +184,6 @@ src_prepare() {
 	llvm.org_src_prepare
 }
 
-# Is LLVM being linked against libc++?
-is_libcxx_linked() {
-	local code='#include <ciso646>
-#if defined(_LIBCPP_VERSION)
-	HAVE_LIBCXX
-#endif
-'
-	local out=$($(tc-getCXX) ${CXXFLAGS} ${CPPFLAGS} -x c++ -E -P - <<<"${code}") || return 1
-
-	[[ ${out} == *HAVE_LIBCXX* ]]
-}
-
 get_distribution_components() {
 	local sep=${1-;}
 
@@ -391,7 +379,7 @@ multilib_src_configure() {
 		# the commit id in the SOVERSION to contain the breakage
 		suffix+="git${EGIT_VERSION::8}"
 	fi
-	if is_libcxx_linked; then
+	if [[ $(tc-get-cxx-stdlib) == libc++ ]]; then
 		# Smart hack: alter version suffix -> SOVERSION when linking
 		# against libc++. This way we won't end up mixing LLVM libc++
 		# libraries with libstdc++ clang, and the other way around.

sys-libs/libcxx/libcxx-13.0.1.ebuild

@@ -89,14 +89,10 @@ multilib_src_configure() {
 		extra_libs+=( -lunwind )
 		# if we're using libunwind and clang with compiler-rt, we want
 		# to link to compiler-rt instead of -lgcc_s
-		if tc-is-clang; then
-			local compiler_rt=$($(tc-getCC) ${CFLAGS} ${CPPFLAGS} \
-			   ${LDFLAGS} -print-libgcc-file-name)
-			if [[ ${compiler_rt} == *libclang_rt* ]]; then
-				want_gcc_s=OFF
-				want_compiler_rt=ON
-				extra_libs+=( "${compiler_rt}" )
-			fi
+		if [[ $(tc-get-c-rtlib) == compiler-rt ]]; then
+			want_gcc_s=OFF
+			want_compiler_rt=ON
+			extra_libs+=( "${compiler_rt}" )
 		fi
 	elif [[ ${CHOST} == *-darwin* ]] && tc-is-clang; then
 		# clang-based darwin prefix disables libunwind useflag during

sys-libs/libcxx/libcxx-14.0.6.ebuild

@@ -97,14 +97,10 @@ multilib_src_configure() {
 		extra_libs+=( -lunwind )
 		# if we're using libunwind and clang with compiler-rt, we want
 		# to link to compiler-rt instead of -lgcc_s
-		if tc-is-clang; then
-			local compiler_rt=$($(tc-getCC) ${CFLAGS} ${CPPFLAGS} \
-			   ${LDFLAGS} -print-libgcc-file-name)
-			if [[ ${compiler_rt} == *libclang_rt* ]]; then
-				want_gcc_s=OFF
-				want_compiler_rt=ON
-				extra_libs+=( "${compiler_rt}" )
-			fi
+		if [[ $(tc-get-c-rtlib) == compiler-rt ]]; then
+			want_gcc_s=OFF
+			want_compiler_rt=ON
+			extra_libs+=( "${compiler_rt}" )
 		fi
 	elif [[ ${CHOST} == *-darwin* ]] && tc-is-clang; then
 		# clang-based darwin prefix disables libunwind useflag during

sys-libs/libcxx/libcxx-15.0.2.ebuild

@@ -95,15 +95,9 @@ multilib_src_configure() {
 		strip-unsupported-flags
 	fi
 
-	# link against compiler-rt instead of libgcc if this is what clang does
-	local want_compiler_rt=OFF
-	if tc-is-clang; then
-		local compiler_rt=$($(tc-getCC) ${CFLAGS} ${CPPFLAGS} \
-			${LDFLAGS} -print-libgcc-file-name)
-		if [[ ${compiler_rt} == *libclang_rt* ]]; then
-			want_compiler_rt=ON
-		fi
-	fi
+	# link to compiler-rt
+	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 )
@@ -131,7 +125,7 @@ multilib_src_configure() {
 		-DLIBCXX_HAS_MUSL_LIBC=$(usex elibc_musl)
 		-DLIBCXX_INCLUDE_BENCHMARKS=OFF
 		-DLIBCXX_INCLUDE_TESTS=$(usex test)
-		-DLIBCXX_USE_COMPILER_RT=${want_compiler_rt}
+		-DLIBCXX_USE_COMPILER_RT=${use_compiler_rt}
 	)
 
 	if use test; then

sys-libs/libcxx/libcxx-15.0.3.9999.ebuild

@@ -94,15 +94,9 @@ multilib_src_configure() {
 		strip-unsupported-flags
 	fi
 
-	# link against compiler-rt instead of libgcc if this is what clang does
-	local want_compiler_rt=OFF
-	if tc-is-clang; then
-		local compiler_rt=$($(tc-getCC) ${CFLAGS} ${CPPFLAGS} \
-			${LDFLAGS} -print-libgcc-file-name)
-		if [[ ${compiler_rt} == *libclang_rt* ]]; then
-			want_compiler_rt=ON
-		fi
-	fi
+	# link to compiler-rt
+	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 )
@@ -130,7 +124,7 @@ multilib_src_configure() {
 		-DLIBCXX_HAS_MUSL_LIBC=$(usex elibc_musl)
 		-DLIBCXX_INCLUDE_BENCHMARKS=OFF
 		-DLIBCXX_INCLUDE_TESTS=$(usex test)
-		-DLIBCXX_USE_COMPILER_RT=${want_compiler_rt}
+		-DLIBCXX_USE_COMPILER_RT=${use_compiler_rt}
 	)
 
 	if use test; then

sys-libs/libcxx/libcxx-16.0.0.9999.ebuild

@@ -94,15 +94,9 @@ multilib_src_configure() {
 		strip-unsupported-flags
 	fi
 
-	# link against compiler-rt instead of libgcc if this is what clang does
-	local want_compiler_rt=OFF
-	if tc-is-clang; then
-		local compiler_rt=$($(tc-getCC) ${CFLAGS} ${CPPFLAGS} \
-			${LDFLAGS} -print-libgcc-file-name)
-		if [[ ${compiler_rt} == *libclang_rt* ]]; then
-			want_compiler_rt=ON
-		fi
-	fi
+	# link to compiler-rt
+	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 )
@@ -130,7 +124,7 @@ multilib_src_configure() {
 		-DLIBCXX_HAS_MUSL_LIBC=$(usex elibc_musl)
 		-DLIBCXX_INCLUDE_BENCHMARKS=OFF
 		-DLIBCXX_INCLUDE_TESTS=$(usex test)
-		-DLIBCXX_USE_COMPILER_RT=${want_compiler_rt}
+		-DLIBCXX_USE_COMPILER_RT=${use_compiler_rt}
 	)
 
 	if use test; then

sys-libs/libcxx/libcxx-16.0.0_pre20221006.ebuild

@@ -94,15 +94,9 @@ multilib_src_configure() {
 		strip-unsupported-flags
 	fi
 
-	# link against compiler-rt instead of libgcc if this is what clang does
-	local want_compiler_rt=OFF
-	if tc-is-clang; then
-		local compiler_rt=$($(tc-getCC) ${CFLAGS} ${CPPFLAGS} \
-			${LDFLAGS} -print-libgcc-file-name)
-		if [[ ${compiler_rt} == *libclang_rt* ]]; then
-			want_compiler_rt=ON
-		fi
-	fi
+	# link to compiler-rt
+	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 )
@@ -130,7 +124,7 @@ multilib_src_configure() {
 		-DLIBCXX_HAS_MUSL_LIBC=$(usex elibc_musl)
 		-DLIBCXX_INCLUDE_BENCHMARKS=OFF
 		-DLIBCXX_INCLUDE_TESTS=$(usex test)
-		-DLIBCXX_USE_COMPILER_RT=${want_compiler_rt}
+		-DLIBCXX_USE_COMPILER_RT=${use_compiler_rt}
 	)
 
 	if use test; then

sys-libs/libcxx/libcxx-16.0.0_pre20221010.ebuild

@@ -94,15 +94,9 @@ multilib_src_configure() {
 		strip-unsupported-flags
 	fi
 
-	# link against compiler-rt instead of libgcc if this is what clang does
-	local want_compiler_rt=OFF
-	if tc-is-clang; then
-		local compiler_rt=$($(tc-getCC) ${CFLAGS} ${CPPFLAGS} \
-			${LDFLAGS} -print-libgcc-file-name)
-		if [[ ${compiler_rt} == *libclang_rt* ]]; then
-			want_compiler_rt=ON
-		fi
-	fi
+	# link to compiler-rt
+	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 )
@@ -130,7 +124,7 @@ multilib_src_configure() {
 		-DLIBCXX_HAS_MUSL_LIBC=$(usex elibc_musl)
 		-DLIBCXX_INCLUDE_BENCHMARKS=OFF
 		-DLIBCXX_INCLUDE_TESTS=$(usex test)
-		-DLIBCXX_USE_COMPILER_RT=${want_compiler_rt}
+		-DLIBCXX_USE_COMPILER_RT=${use_compiler_rt}
 	)
 
 	if use test; then

sys-libs/libcxxabi/libcxxabi-13.0.1.ebuild

@@ -53,12 +53,8 @@ multilib_src_configure() {
 
 	# link against compiler-rt instead of libgcc if we are using clang with libunwind
 	local want_compiler_rt=OFF
-	if use libunwind && tc-is-clang; then
-		local compiler_rt=$($(tc-getCC) ${CFLAGS} ${CPPFLAGS} \
-			${LDFLAGS} -print-libgcc-file-name)
-		if [[ ${compiler_rt} == *libclang_rt* ]]; then
-			want_compiler_rt=ON
-		fi
+	if use libunwind && [[ $(tc-get-c-rtlib) == compiler-rt ]]; then
+		want_compiler_rt=ON
 	fi
 
 	local libdir=$(get_libdir)

sys-libs/libcxxabi/libcxxabi-14.0.6.ebuild

@@ -59,12 +59,8 @@ pkg_setup() {
 multilib_src_configure() {
 	# link against compiler-rt instead of libgcc if we are using clang with libunwind
 	local want_compiler_rt=OFF
-	if use libunwind && tc-is-clang; then
-		local compiler_rt=$($(tc-getCC) ${CFLAGS} ${CPPFLAGS} \
-			${LDFLAGS} -print-libgcc-file-name)
-		if [[ ${compiler_rt} == *libclang_rt* ]]; then
-			want_compiler_rt=ON
-		fi
+	if use libunwind && [[ $(tc-get-c-rtlib) == compiler-rt ]]; then
+		want_compiler_rt=ON
 	fi
 
 	local libdir=$(get_libdir)

sys-libs/libcxxabi/libcxxabi-15.0.2.ebuild

@@ -63,15 +63,9 @@ multilib_src_configure() {
 		strip-unsupported-flags
 	fi
 
-	# link against compiler-rt instead of libgcc if this is what clang does
-	local want_compiler_rt=OFF
-	if tc-is-clang; then
-		local compiler_rt=$($(tc-getCC) ${CFLAGS} ${CPPFLAGS} \
-			${LDFLAGS} -print-libgcc-file-name)
-		if [[ ${compiler_rt} == *libclang_rt* ]]; then
-			want_compiler_rt=ON
-		fi
-	fi
+	# link to compiler-rt
+	local use_compiler_rt=OFF
+	[[ $(tc-get-c-rtlib) == compiler-rt ]] && use_compiler_rt=ON
 
 	local libdir=$(get_libdir)
 	local mycmakeargs=(
@@ -83,7 +77,7 @@ multilib_src_configure() {
 		-DLIBCXXABI_ENABLE_SHARED=ON
 		-DLIBCXXABI_ENABLE_STATIC=$(usex static-libs)
 		-DLIBCXXABI_INCLUDE_TESTS=$(usex test)
-		-DLIBCXXABI_USE_COMPILER_RT=${want_compiler_rt}
+		-DLIBCXXABI_USE_COMPILER_RT=${use_compiler_rt}
 
 		# upstream is omitting standard search path for this
 		# probably because gcc & clang are bundling their own unwind.h

sys-libs/libcxxabi/libcxxabi-15.0.3.9999.ebuild

@@ -62,15 +62,9 @@ multilib_src_configure() {
 		strip-unsupported-flags
 	fi
 
-	# link against compiler-rt instead of libgcc if this is what clang does
-	local want_compiler_rt=OFF
-	if tc-is-clang; then
-		local compiler_rt=$($(tc-getCC) ${CFLAGS} ${CPPFLAGS} \
-			${LDFLAGS} -print-libgcc-file-name)
-		if [[ ${compiler_rt} == *libclang_rt* ]]; then
-			want_compiler_rt=ON
-		fi
-	fi
+	# link to compiler-rt
+	local use_compiler_rt=OFF
+	[[ $(tc-get-c-rtlib) == compiler-rt ]] && use_compiler_rt=ON
 
 	local libdir=$(get_libdir)
 	local mycmakeargs=(
@@ -82,7 +76,7 @@ multilib_src_configure() {
 		-DLIBCXXABI_ENABLE_SHARED=ON
 		-DLIBCXXABI_ENABLE_STATIC=$(usex static-libs)
 		-DLIBCXXABI_INCLUDE_TESTS=$(usex test)
-		-DLIBCXXABI_USE_COMPILER_RT=${want_compiler_rt}
+		-DLIBCXXABI_USE_COMPILER_RT=${use_compiler_rt}
 
 		# upstream is omitting standard search path for this
 		# probably because gcc & clang are bundling their own unwind.h

sys-libs/libcxxabi/libcxxabi-16.0.0.9999.ebuild

@@ -62,15 +62,9 @@ multilib_src_configure() {
 		strip-unsupported-flags
 	fi
 
-	# link against compiler-rt instead of libgcc if this is what clang does
-	local want_compiler_rt=OFF
-	if tc-is-clang; then
-		local compiler_rt=$($(tc-getCC) ${CFLAGS} ${CPPFLAGS} \
-			${LDFLAGS} -print-libgcc-file-name)
-		if [[ ${compiler_rt} == *libclang_rt* ]]; then
-			want_compiler_rt=ON
-		fi
-	fi
+	# link to compiler-rt
+	local use_compiler_rt=OFF
+	[[ $(tc-get-c-rtlib) == compiler-rt ]] && use_compiler_rt=ON
 
 	local libdir=$(get_libdir)
 	local mycmakeargs=(
@@ -82,7 +76,7 @@ multilib_src_configure() {
 		-DLIBCXXABI_ENABLE_SHARED=ON
 		-DLIBCXXABI_ENABLE_STATIC=$(usex static-libs)
 		-DLIBCXXABI_INCLUDE_TESTS=$(usex test)
-		-DLIBCXXABI_USE_COMPILER_RT=${want_compiler_rt}
+		-DLIBCXXABI_USE_COMPILER_RT=${use_compiler_rt}
 
 		# upstream is omitting standard search path for this
 		# probably because gcc & clang are bundling their own unwind.h

sys-libs/libcxxabi/libcxxabi-16.0.0_pre20221006.ebuild

@@ -62,15 +62,9 @@ multilib_src_configure() {
 		strip-unsupported-flags
 	fi
 
-	# link against compiler-rt instead of libgcc if this is what clang does
-	local want_compiler_rt=OFF
-	if tc-is-clang; then
-		local compiler_rt=$($(tc-getCC) ${CFLAGS} ${CPPFLAGS} \
-			${LDFLAGS} -print-libgcc-file-name)
-		if [[ ${compiler_rt} == *libclang_rt* ]]; then
-			want_compiler_rt=ON
-		fi
-	fi
+	# link to compiler-rt
+	local use_compiler_rt=OFF
+	[[ $(tc-get-c-rtlib) == compiler-rt ]] && use_compiler_rt=ON
 
 	local libdir=$(get_libdir)
 	local mycmakeargs=(
@@ -82,7 +76,7 @@ multilib_src_configure() {
 		-DLIBCXXABI_ENABLE_SHARED=ON
 		-DLIBCXXABI_ENABLE_STATIC=$(usex static-libs)
 		-DLIBCXXABI_INCLUDE_TESTS=$(usex test)
-		-DLIBCXXABI_USE_COMPILER_RT=${want_compiler_rt}
+		-DLIBCXXABI_USE_COMPILER_RT=${use_compiler_rt}
 
 		# upstream is omitting standard search path for this
 		# probably because gcc & clang are bundling their own unwind.h

sys-libs/libcxxabi/libcxxabi-16.0.0_pre20221010.ebuild

@@ -62,15 +62,9 @@ multilib_src_configure() {
 		strip-unsupported-flags
 	fi
 
-	# link against compiler-rt instead of libgcc if this is what clang does
-	local want_compiler_rt=OFF
-	if tc-is-clang; then
-		local compiler_rt=$($(tc-getCC) ${CFLAGS} ${CPPFLAGS} \
-			${LDFLAGS} -print-libgcc-file-name)
-		if [[ ${compiler_rt} == *libclang_rt* ]]; then
-			want_compiler_rt=ON
-		fi
-	fi
+	# link to compiler-rt
+	local use_compiler_rt=OFF
+	[[ $(tc-get-c-rtlib) == compiler-rt ]] && use_compiler_rt=ON
 
 	local libdir=$(get_libdir)
 	local mycmakeargs=(
@@ -82,7 +76,7 @@ multilib_src_configure() {
 		-DLIBCXXABI_ENABLE_SHARED=ON
 		-DLIBCXXABI_ENABLE_STATIC=$(usex static-libs)
 		-DLIBCXXABI_INCLUDE_TESTS=$(usex test)
-		-DLIBCXXABI_USE_COMPILER_RT=${want_compiler_rt}
+		-DLIBCXXABI_USE_COMPILER_RT=${use_compiler_rt}
 
 		# upstream is omitting standard search path for this
 		# probably because gcc & clang are bundling their own unwind.h

sys-libs/llvm-libunwind/llvm-libunwind-13.0.1-r1.ebuild

@@ -38,7 +38,6 @@ pkg_setup() {
 }
 
 multilib_src_configure() {
-	local use_compiler_rt=OFF
 	local libdir=$(get_libdir)
 
 	# https://github.com/llvm/llvm-project/issues/56825
@@ -47,13 +46,8 @@ multilib_src_configure() {
 
 	# link to compiler-rt
 	# https://github.com/gentoo/gentoo/pull/21516
-	if tc-is-clang; then
-		local compiler_rt=$($(tc-getCC) ${CFLAGS} ${CPPFLAGS} \
-		   ${LD_FLAGS} -print-libgcc-file-name)
-		if [[ ${compiler_rt} == *libclang_rt* ]]; then
-			use_compiler_rt=ON
-		fi
-	fi
+	local use_compiler_rt=OFF
+	[[ $(tc-get-c-rtlib) == compiler-rt ]] && use_compiler_rt=ON
 
 	local mycmakeargs=(
 		-DLLVM_LIBDIR_SUFFIX=${libdir#lib}

sys-libs/llvm-libunwind/llvm-libunwind-14.0.6-r1.ebuild

@@ -42,7 +42,6 @@ python_check_deps() {
 }
 
 multilib_src_configure() {
-	local use_compiler_rt=OFF
 	local libdir=$(get_libdir)
 
 	# https://github.com/llvm/llvm-project/issues/56825
@@ -51,13 +50,8 @@ multilib_src_configure() {
 
 	# link to compiler-rt
 	# https://github.com/gentoo/gentoo/pull/21516
-	if tc-is-clang; then
-		local compiler_rt=$($(tc-getCC) ${CFLAGS} ${CPPFLAGS} \
-		   ${LD_FLAGS} -print-libgcc-file-name)
-		if [[ ${compiler_rt} == *libclang_rt* ]]; then
-			use_compiler_rt=ON
-		fi
-	fi
+	local use_compiler_rt=OFF
+	[[ $(tc-get-c-rtlib) == compiler-rt ]] && use_compiler_rt=ON
 
 	local mycmakeargs=(
 		-DPython3_EXECUTABLE="${PYTHON}"

sys-libs/llvm-libunwind/llvm-libunwind-15.0.2.ebuild

@@ -51,7 +51,6 @@ pkg_setup() {
 }
 
 multilib_src_configure() {
-	local use_compiler_rt=OFF
 	local libdir=$(get_libdir)
 
 	# https://github.com/llvm/llvm-project/issues/56825
@@ -66,13 +65,8 @@ multilib_src_configure() {
 
 	# link to compiler-rt
 	# https://github.com/gentoo/gentoo/pull/21516
-	if tc-is-clang; then
-		local compiler_rt=$($(tc-getCC) ${CFLAGS} ${CPPFLAGS} \
-		   ${LD_FLAGS} -print-libgcc-file-name)
-		if [[ ${compiler_rt} == *libclang_rt* ]]; then
-			use_compiler_rt=ON
-		fi
-	fi
+	local use_compiler_rt=OFF
+	[[ $(tc-get-c-rtlib) == compiler-rt ]] && use_compiler_rt=ON
 
 	local mycmakeargs=(
 		-DCMAKE_CXX_COMPILER_TARGET="${CHOST}"

sys-libs/llvm-libunwind/llvm-libunwind-15.0.3.9999.ebuild

@@ -50,7 +50,6 @@ pkg_setup() {
 }
 
 multilib_src_configure() {
-	local use_compiler_rt=OFF
 	local libdir=$(get_libdir)
 
 	# https://github.com/llvm/llvm-project/issues/56825
@@ -65,13 +64,8 @@ multilib_src_configure() {
 
 	# link to compiler-rt
 	# https://github.com/gentoo/gentoo/pull/21516
-	if tc-is-clang; then
-		local compiler_rt=$($(tc-getCC) ${CFLAGS} ${CPPFLAGS} \
-		   ${LD_FLAGS} -print-libgcc-file-name)
-		if [[ ${compiler_rt} == *libclang_rt* ]]; then
-			use_compiler_rt=ON
-		fi
-	fi
+	local use_compiler_rt=OFF
+	[[ $(tc-get-c-rtlib) == compiler-rt ]] && use_compiler_rt=ON
 
 	local mycmakeargs=(
 		-DCMAKE_CXX_COMPILER_TARGET="${CHOST}"

sys-libs/llvm-libunwind/llvm-libunwind-16.0.0.9999.ebuild

@@ -50,7 +50,6 @@ pkg_setup() {
 }
 
 multilib_src_configure() {
-	local use_compiler_rt=OFF
 	local libdir=$(get_libdir)
 
 	# https://github.com/llvm/llvm-project/issues/56825
@@ -65,13 +64,8 @@ multilib_src_configure() {
 
 	# link to compiler-rt
 	# https://github.com/gentoo/gentoo/pull/21516
-	if tc-is-clang; then
-		local compiler_rt=$($(tc-getCC) ${CFLAGS} ${CPPFLAGS} \
-		   ${LD_FLAGS} -print-libgcc-file-name)
-		if [[ ${compiler_rt} == *libclang_rt* ]]; then
-			use_compiler_rt=ON
-		fi
-	fi
+	local use_compiler_rt=OFF
+	[[ $(tc-get-c-rtlib) == compiler-rt ]] && use_compiler_rt=ON
 
 	local mycmakeargs=(
 		-DCMAKE_CXX_COMPILER_TARGET="${CHOST}"

sys-libs/llvm-libunwind/llvm-libunwind-16.0.0_pre20221006.ebuild

@@ -50,7 +50,6 @@ pkg_setup() {
 }
 
 multilib_src_configure() {
-	local use_compiler_rt=OFF
 	local libdir=$(get_libdir)
 
 	# https://github.com/llvm/llvm-project/issues/56825
@@ -65,13 +64,8 @@ multilib_src_configure() {
 
 	# link to compiler-rt
 	# https://github.com/gentoo/gentoo/pull/21516
-	if tc-is-clang; then
-		local compiler_rt=$($(tc-getCC) ${CFLAGS} ${CPPFLAGS} \
-		   ${LD_FLAGS} -print-libgcc-file-name)
-		if [[ ${compiler_rt} == *libclang_rt* ]]; then
-			use_compiler_rt=ON
-		fi
-	fi
+	local use_compiler_rt=OFF
+	[[ $(tc-get-c-rtlib) == compiler-rt ]] && use_compiler_rt=ON
 
 	local mycmakeargs=(
 		-DCMAKE_CXX_COMPILER_TARGET="${CHOST}"

sys-libs/llvm-libunwind/llvm-libunwind-16.0.0_pre20221010.ebuild

@@ -50,7 +50,6 @@ pkg_setup() {
 }
 
 multilib_src_configure() {
-	local use_compiler_rt=OFF
 	local libdir=$(get_libdir)
 
 	# https://github.com/llvm/llvm-project/issues/56825
@@ -65,13 +64,8 @@ multilib_src_configure() {
 
 	# link to compiler-rt
 	# https://github.com/gentoo/gentoo/pull/21516
-	if tc-is-clang; then
-		local compiler_rt=$($(tc-getCC) ${CFLAGS} ${CPPFLAGS} \
-		   ${LD_FLAGS} -print-libgcc-file-name)
-		if [[ ${compiler_rt} == *libclang_rt* ]]; then
-			use_compiler_rt=ON
-		fi
-	fi
+	local use_compiler_rt=OFF
+	[[ $(tc-get-c-rtlib) == compiler-rt ]] && use_compiler_rt=ON
 
 	local mycmakeargs=(
 		-DCMAKE_CXX_COMPILER_TARGET="${CHOST}"
@@ -80,13 +74,11 @@ multilib_src_configure() {
 		-DLLVM_LIBDIR_SUFFIX=${libdir#lib}
 		-DLLVM_INCLUDE_TESTS=OFF
 		-DLIBUNWIND_ENABLE_ASSERTIONS=$(usex debug)
+		-DLIBUNWIND_ENABLE_CROSS_UNWINDING=ON
 		-DLIBUNWIND_ENABLE_STATIC=$(usex static-libs)
 		-DLIBUNWIND_INCLUDE_TESTS=$(usex test)
 		-DLIBUNWIND_INSTALL_HEADERS=ON
 
-		# temporarily disabled due to upstream regression
-		-DLIBUNWIND_ENABLE_CROSS_UNWINDING=OFF
-
 		# avoid dependency on libgcc_s if compiler-rt is used
 		-DLIBUNWIND_USE_COMPILER_RT=${use_compiler_rt}
 	)