Add back older clang versions: 15 and 16 (nanbield)

classes/clang15-native.bbclass

@@ -0,0 +1,23 @@
+# inherit this class if you would like to use clang 15 to compile the native
+# version of your recipes instead of system compiler ( which is normally gcc )
+# on build machines
+# to use it add
+#
+# inherit clang15-native
+#
+# to the concerned recipe via a bbappend or directly to recipe file
+#
+DEPENDS:append:runtime-llvm = " clang15-native compiler-rt15-native libcxx15-initial-native"
+# Use libcxx headers for native parts
+CXXFLAGS:append:runtime-llvm = " -stdlib=libc++"
+BUILD_CXXFLAGS:append:runtime-llvm = " -isysroot=${STAGING_DIR_NATIVE} -stdlib=libc++"
+# Use libgcc for native parts
+LDFLAGS:append:runtime-llvm = " -stdlib=libc++ -rtlib=libgcc -unwindlib=libgcc"
+BUILD_LDFLAGS:append:runtime-llvm = " -stdlib=libc++ -rtlib=libgcc -unwindlib=libgcc"
+BUILD_CC:runtime-llvm  = "${CCACHE}clang -isysroot=${STAGING_DIR_NATIVE}"
+BUILD_CXX:runtime-llvm = "${CCACHE}clang++ -isysroot=${STAGING_DIR_NATIVE}"
+BUILD_CPP:runtime-llvm = "${CCACHE}clang -isysroot=${STAGING_DIR_NATIVE} -E"
+BUILD_CCLD:runtime-llvm = "${CCACHE}clang"
+BUILD_RANLIB:runtime-llvm = "llvm-ranlib"
+BUILD_AR:runtime-llvm = "llvm-ar"
+BUILD_NM:runtime-llvm = "llvm-nm"

classes/clang15.bbclass

@@ -0,0 +1,159 @@
+# Add the necessary override
+CCACHE_COMPILERCHECK:toolchain-clang15 ?= "%compiler% -v"
+HOST_CC_ARCH:prepend:toolchain-clang15 = "-target ${HOST_SYS} "
+CC:toolchain-clang15  = "${CCACHE}${HOST_PREFIX}clang ${HOST_CC_ARCH}${TOOLCHAIN_OPTIONS}"
+CXX:toolchain-clang15 = "${CCACHE}${HOST_PREFIX}clang++ ${HOST_CC_ARCH}${TOOLCHAIN_OPTIONS}"
+CPP:toolchain-clang15 = "${CCACHE}${HOST_PREFIX}clang ${HOST_CC_ARCH}${TOOLCHAIN_OPTIONS} -E"
+CCLD:toolchain-clang15 = "${CCACHE}${HOST_PREFIX}clang ${HOST_CC_ARCH}${TOOLCHAIN_OPTIONS}"
+RANLIB:toolchain-clang15 = "${HOST_PREFIX}llvm-ranlib"
+AR:toolchain-clang15 = "${HOST_PREFIX}llvm-ar"
+NM:toolchain-clang15 = "${HOST_PREFIX}llvm-nm"
+OBJDUMP:toolchain-clang15 = "${HOST_PREFIX}llvm-objdump"
+OBJCOPY:toolchain-clang15 = "${HOST_PREFIX}llvm-objcopy"
+STRIP:riscv64:toolchain-clang15 = "${HOST_PREFIX}llvm-strip"
+STRIP:riscv32:toolchain-clang15 = "${HOST_PREFIX}llvm-strip"
+STRINGS:toolchain-clang15 = "${HOST_PREFIX}llvm-strings"
+READELF:toolchain-clang15 = "${HOST_PREFIX}llvm-readelf"
+
+LTO:toolchain-clang15 = "${@bb.utils.contains('DISTRO_FEATURES', 'thin-lto', '-flto=thin', '-flto -fuse-ld=lld', d)}"
+
+COMPILER_RT ??= ""
+COMPILER_RT:class-native = "-rtlib=libgcc ${UNWINDLIB}"
+COMPILER_RT:armeb = "-rtlib=libgcc ${UNWINDLIB}"
+COMPILER_RT:libc-klibc = "-rtlib=libgcc ${UNWINDLIB}"
+
+UNWINDLIB ??= ""
+UNWINDLIB:class-native = "--unwindlib=libgcc"
+UNWINDLIB:armeb = "--unwindlib=libgcc"
+UNWINDLIB_libc-klibc = "--unwindlib=libgcc"
+
+LIBCPLUSPLUS ??= ""
+LIBCPLUSPLUS:armv5 = "-stdlib=libstdc++"
+
+CXXFLAGS:append:toolchain-clang15 = " ${LIBCPLUSPLUS}"
+LDFLAGS:append:toolchain-clang15 = " ${COMPILER_RT} ${LIBCPLUSPLUS}"
+
+TUNE_CCARGS:remove:toolchain-clang15 = "-meb"
+TUNE_CCARGS:remove:toolchain-clang15 = "-mel"
+TUNE_CCARGS:append:toolchain-clang15 = "${@bb.utils.contains("TUNE_FEATURES", "bigendian", " -mbig-endian", " -mlittle-endian", d)}"
+
+# Clang does not yet support big.LITTLE performance tunes, so use the LITTLE for tunes
+TUNE_CCARGS:remove:toolchain-clang15 = "-mcpu=cortex-a57.cortex-a53 -mcpu=cortex-a72.cortex-a53 -mcpu=cortex-a15.cortex-a7 -mcpu=cortex-a17.cortex-a7 -mcpu=cortex-a72.cortex-a35 -mcpu=cortex-a73.cortex-a53 -mcpu=cortex-a75.cortex-a55 -mcpu=cortex-a76.cortex-a55"
+TUNE_CCARGS:append:toolchain-clang15 = "${@bb.utils.contains_any("TUNE_FEATURES", "cortexa72-cortexa53 cortexa57-cortexa53 cortexa73-cortexa53", " -mcpu=cortex-a53", "", d)}"
+TUNE_CCARGS:append:toolchain-clang15 = "${@bb.utils.contains_any("TUNE_FEATURES", "cortexa15-cortexa7 cortexa17-cortexa7", " -mcpu=cortex-a7", "", d)}"
+TUNE_CCARGS:append:toolchain-clang15 = "${@bb.utils.contains_any("TUNE_FEATURES", "cortexa72-cortexa35", " -mcpu=cortex-a35", "", d)}"
+TUNE_CCARGS:append:toolchain-clang15 = "${@bb.utils.contains_any("TUNE_FEATURES", "cortexa75-cortexa55 cortexa76-cortexa55", " -mcpu=cortex-a55", "", d)}"
+
+# Clang does not support octeontx2 processor
+TUNE_CCARGS:remove:toolchain-clang15 = "-mcpu=octeontx2"
+
+# Reconcile some ppc anamolies
+TUNE_CCARGS:remove:toolchain-clang15:powerpc = "-mhard-float -mno-spe"
+TUNE_CCARGS:append:toolchain-clang15:libc-musl:powerpc64 = " -mlong-double-64"
+TUNE_CCARGS:append:toolchain-clang15:libc-musl:powerpc64le = " -mlong-double-64"
+TUNE_CCARGS:append:toolchain-clang15:libc-musl:powerpc = " -mlong-double-64"
+# usrmerge workaround
+TUNE_CCARGS:append:toolchain-clang15 = "${@bb.utils.contains("DISTRO_FEATURES", "usrmerge", " --dyld-prefix=/usr", "", d)}"
+
+TUNE_CCARGS:append:toolchain-clang15 = " -Qunused-arguments"
+
+LDFLAGS:append:toolchain-clang15:class-nativesdk:x86-64 = " -Wl,-dynamic-linker,${base_libdir}/ld-linux-x86-64.so.2"
+LDFLAGS:append:toolchain-clang15:class-nativesdk:x86 = " -Wl,-dynamic-linker,${base_libdir}/ld-linux.so.2"
+LDFLAGS:append:toolchain-clang15:class-nativesdk:aarch64 = " -Wl,-dynamic-linker,${base_libdir}/ld-linux-aarch64.so.1"
+
+LDFLAGS:toolchain-clang15:class-nativesdk = "${BUILDSDK_LDFLAGS} \
+                                           -Wl,-rpath-link,${STAGING_LIBDIR}/.. \
+                                           -Wl,-rpath,${libdir}/.. "
+
+# Enable lld globally"
+LDFLAGS:append:toolchain-clang15 = "${@bb.utils.contains('DISTRO_FEATURES', 'ld-is-lld', ' -fuse-ld=lld', '', d)}"
+
+# Remove gcc specific -fcanon-prefix-map option, added in gcc-13+
+# clang does not support it yet
+DEBUG_PREFIX_MAP:remove:toolchain-clang15 = "-fcanon-prefix-map"
+
+# choose between 'gcc' 'clang' an empty '' can be used as well
+TOOLCHAIN ??= "gcc"
+# choose between 'gnu' 'llvm'
+TC_CXX_RUNTIME ??= "gnu"
+# Using gcc or llvm runtime is only available when using clang for compiler
+#TC_CXX_RUNTIME:toolchain-gcc = "gnu"
+TC_CXX_RUNTIME:armeb = "gnu"
+TC_CXX_RUNTIME:armv5 = "gnu"
+
+TOOLCHAIN:class-native = "gcc"
+TOOLCHAIN:class-nativesdk = "gcc"
+TOOLCHAIN:class-cross-canadian = "gcc"
+TOOLCHAIN:class-crosssdk = "gcc"
+TOOLCHAIN:class-cross = "gcc"
+
+OVERRIDES =. "${@['', 'toolchain-${TOOLCHAIN}:']['${TOOLCHAIN}' != '']}"
+OVERRIDES =. "${@['', 'runtime-${TC_CXX_RUNTIME}:']['${TC_CXX_RUNTIME}' != '']}"
+OVERRIDES[vardepsexclude] += "TOOLCHAIN TC_CXX_RUNTIME"
+
+YOCTO_ALTERNATE_EXE_PATH:toolchain-clang15:class-target = "${STAGING_BINDIR}/llvm-config"
+YOCTO_ALTERNATE_LIBDIR:toolchain-clang15:class-target = "/${BASELIB}"
+
+#YOCTO_ALTERNATE_EXE_PATH:toolchain-clang15:class-target[export] = "1"
+#YOCTO_ALTERNATE_LIBDIR:toolchain-clang15:class-target[export] = "1"
+
+#DEPENDS:append:toolchain-clang15:class-target = " clang15-cross-${TARGET_ARCH} "
+#DEPENDS:remove:toolchain-clang15:allarch = "clang15-cross-${TARGET_ARCH}"
+
+def clang_base_deps(d):
+    if not d.getVar('INHIBIT_DEFAULT_DEPS', False):
+        if not oe.utils.inherits(d, 'allarch') :
+            ret = " ${MLPREFIX}clang15-cross-${TARGET_ARCH} virtual/libc "
+            if (d.getVar('TC_CXX_RUNTIME').find('android') != -1):
+                ret += " libcxx15-initial"
+                return ret
+            if (d.getVar('TC_CXX_RUNTIME').find('llvm') != -1):
+                ret += " compiler-rt15"
+            elif (d.getVar('COMPILER_RT').find('-rtlib=compiler-rt') != -1):
+                ret += " compiler-rt15 "
+            else:
+                ret += " libgcc "
+            if (d.getVar('TC_CXX_RUNTIME').find('llvm') != -1):
+                ret += " libcxx15-initial"
+            elif (d.getVar('COMPILER_RT').find('--unwindlib=libunwind') != -1):
+                ret += " libcxx15-initial "
+            elif (d.getVar('LIBCPLUSPLUS').find('-stdlib=libc++') != -1):
+                ret += " libcxx15-initial "
+            else:
+                ret += " virtual/${TARGET_PREFIX}compilerlibs "
+            return ret
+    return ""
+
+BASE_DEFAULT_DEPS:toolchain-clang15:class-target = "${@clang_base_deps(d)}"
+BASE_DEFAULT_DEPS:append:class-native:toolchain-clang15:runtime-llvm = " libcxx15-initial-native compiler-rt15-native"
+BASE_DEFAULT_DEPS:append:class-nativesdk:toolchain-clang15:runtime-llvm = " clang15-native nativesdk-libcxx15-initial nativesdk-compiler-rt15"
+
+# do_populate_sysroot needs STRIP
+POPULATESYSROOTDEPS:toolchain-clang15:class-target = "${MLPREFIX}clang15-cross-${TARGET_ARCH}:do_populate_sysroot"
+
+cmake_do_generate_toolchain_file:append:toolchain-clang15 () {
+    cat >> ${WORKDIR}/toolchain.cmake <<EOF
+set( CMAKE_CLANG_TIDY ${HOST_PREFIX}clang-tidy )
+EOF
+    sed -i 's/ -mmusl / /g' ${WORKDIR}/toolchain.cmake
+}
+
+RECIPESYSROOTFUNCS = ""
+RECIPESYSROOTFUNCS:toolchain-clang15 = "recipe_sysroot_check_ld_is_lld"
+
+recipe_sysroot_check_ld_is_lld () {
+    if ${@bb.utils.contains('DISTRO_FEATURES', 'ld-is-lld', 'true', 'false', d)} &&  \
+        [ -e ${STAGING_BINDIR_TOOLCHAIN}/${TARGET_PREFIX}ld.lld ]; then
+        ln -srf ${STAGING_BINDIR_TOOLCHAIN}/${TARGET_PREFIX}ld.lld ${STAGING_BINDIR_TOOLCHAIN}/${TARGET_PREFIX}ld
+    fi
+}
+do_prepare_recipe_sysroot[postfuncs] += "${RECIPESYSROOTFUNCS}"
+#
+# dump recipes which still use gcc
+#python __anonymous() {
+#    toolchain = d.getVar("TOOLCHAIN")
+#    if not toolchain or toolchain == "clang" or 'class-target' not in d.getVar('OVERRIDES').split(':'):
+#        return
+#    pkgn = d.getVar("PN")
+#    bb.warn("%s - %s" % (pkgn, toolchain))
+#}

classes/clang16-native.bbclass

@@ -0,0 +1,23 @@
+# inherit this class if you would like to use clang 16 to compile the native
+# version of your recipes instead of system compiler ( which is normally gcc )
+# on build machines
+# to use it add
+#
+# inherit clang16-native
+#
+# to the concerned recipe via a bbappend or directly to recipe file
+#
+DEPENDS:append:runtime-llvm = " clang16-native compiler-rt16-native libcxx16-initial-native"
+# Use libcxx headers for native parts
+CXXFLAGS:append:runtime-llvm = " -stdlib=libc++"
+BUILD_CXXFLAGS:append:runtime-llvm = " -isysroot=${STAGING_DIR_NATIVE} -stdlib=libc++"
+# Use libgcc for native parts
+LDFLAGS:append:runtime-llvm = " -stdlib=libc++ -rtlib=libgcc -unwindlib=libgcc"
+BUILD_LDFLAGS:append:runtime-llvm = " -stdlib=libc++ -rtlib=libgcc -unwindlib=libgcc"
+BUILD_CC:runtime-llvm  = "${CCACHE}clang -isysroot=${STAGING_DIR_NATIVE}"
+BUILD_CXX:runtime-llvm = "${CCACHE}clang++ -isysroot=${STAGING_DIR_NATIVE}"
+BUILD_CPP:runtime-llvm = "${CCACHE}clang -isysroot=${STAGING_DIR_NATIVE} -E"
+BUILD_CCLD:runtime-llvm = "${CCACHE}clang"
+BUILD_RANLIB:runtime-llvm = "llvm-ranlib"
+BUILD_AR:runtime-llvm = "llvm-ar"
+BUILD_NM:runtime-llvm = "llvm-nm"

classes/clang16.bbclass

@@ -0,0 +1,159 @@
+# Add the necessary override
+CCACHE_COMPILERCHECK:toolchain-clang16 ?= "%compiler% -v"
+HOST_CC_ARCH:prepend:toolchain-clang16 = "-target ${HOST_SYS} "
+CC:toolchain-clang16  = "${CCACHE}${HOST_PREFIX}clang ${HOST_CC_ARCH}${TOOLCHAIN_OPTIONS}"
+CXX:toolchain-clang16 = "${CCACHE}${HOST_PREFIX}clang++ ${HOST_CC_ARCH}${TOOLCHAIN_OPTIONS}"
+CPP:toolchain-clang16 = "${CCACHE}${HOST_PREFIX}clang ${HOST_CC_ARCH}${TOOLCHAIN_OPTIONS} -E"
+CCLD:toolchain-clang16 = "${CCACHE}${HOST_PREFIX}clang ${HOST_CC_ARCH}${TOOLCHAIN_OPTIONS}"
+RANLIB:toolchain-clang16 = "${HOST_PREFIX}llvm-ranlib"
+AR:toolchain-clang16 = "${HOST_PREFIX}llvm-ar"
+NM:toolchain-clang16 = "${HOST_PREFIX}llvm-nm"
+OBJDUMP:toolchain-clang16 = "${HOST_PREFIX}llvm-objdump"
+OBJCOPY:toolchain-clang16 = "${HOST_PREFIX}llvm-objcopy"
+STRIP:riscv64:toolchain-clang16 = "${HOST_PREFIX}llvm-strip"
+STRIP:riscv32:toolchain-clang16 = "${HOST_PREFIX}llvm-strip"
+STRINGS:toolchain-clang16 = "${HOST_PREFIX}llvm-strings"
+READELF:toolchain-clang16 = "${HOST_PREFIX}llvm-readelf"
+
+LTO:toolchain-clang16 = "${@bb.utils.contains('DISTRO_FEATURES', 'thin-lto', '-flto=thin', '-flto -fuse-ld=lld', d)}"
+
+COMPILER_RT ??= ""
+COMPILER_RT:class-native = "-rtlib=libgcc ${UNWINDLIB}"
+COMPILER_RT:armeb = "-rtlib=libgcc ${UNWINDLIB}"
+COMPILER_RT:libc-klibc = "-rtlib=libgcc ${UNWINDLIB}"
+
+UNWINDLIB ??= ""
+UNWINDLIB:class-native = "--unwindlib=libgcc"
+UNWINDLIB:armeb = "--unwindlib=libgcc"
+UNWINDLIB_libc-klibc = "--unwindlib=libgcc"
+
+LIBCPLUSPLUS ??= ""
+LIBCPLUSPLUS:armv5 = "-stdlib=libstdc++"
+
+CXXFLAGS:append:toolchain-clang16 = " ${LIBCPLUSPLUS}"
+LDFLAGS:append:toolchain-clang16 = " ${COMPILER_RT} ${LIBCPLUSPLUS}"
+
+TUNE_CCARGS:remove:toolchain-clang16 = "-meb"
+TUNE_CCARGS:remove:toolchain-clang16 = "-mel"
+TUNE_CCARGS:append:toolchain-clang16 = "${@bb.utils.contains("TUNE_FEATURES", "bigendian", " -mbig-endian", " -mlittle-endian", d)}"
+
+# Clang does not yet support big.LITTLE performance tunes, so use the LITTLE for tunes
+TUNE_CCARGS:remove:toolchain-clang16 = "-mcpu=cortex-a57.cortex-a53 -mcpu=cortex-a72.cortex-a53 -mcpu=cortex-a15.cortex-a7 -mcpu=cortex-a17.cortex-a7 -mcpu=cortex-a72.cortex-a35 -mcpu=cortex-a73.cortex-a53 -mcpu=cortex-a75.cortex-a55 -mcpu=cortex-a76.cortex-a55"
+TUNE_CCARGS:append:toolchain-clang16 = "${@bb.utils.contains_any("TUNE_FEATURES", "cortexa72-cortexa53 cortexa57-cortexa53 cortexa73-cortexa53", " -mcpu=cortex-a53", "", d)}"
+TUNE_CCARGS:append:toolchain-clang16 = "${@bb.utils.contains_any("TUNE_FEATURES", "cortexa15-cortexa7 cortexa17-cortexa7", " -mcpu=cortex-a7", "", d)}"
+TUNE_CCARGS:append:toolchain-clang16 = "${@bb.utils.contains_any("TUNE_FEATURES", "cortexa72-cortexa35", " -mcpu=cortex-a35", "", d)}"
+TUNE_CCARGS:append:toolchain-clang16 = "${@bb.utils.contains_any("TUNE_FEATURES", "cortexa75-cortexa55 cortexa76-cortexa55", " -mcpu=cortex-a55", "", d)}"
+
+# Clang does not support octeontx2 processor
+TUNE_CCARGS:remove:toolchain-clang16 = "-mcpu=octeontx2"
+
+# Reconcile some ppc anamolies
+TUNE_CCARGS:remove:toolchain-clang16:powerpc = "-mhard-float -mno-spe"
+TUNE_CCARGS:append:toolchain-clang16:libc-musl:powerpc64 = " -mlong-double-64"
+TUNE_CCARGS:append:toolchain-clang16:libc-musl:powerpc64le = " -mlong-double-64"
+TUNE_CCARGS:append:toolchain-clang16:libc-musl:powerpc = " -mlong-double-64"
+# usrmerge workaround
+TUNE_CCARGS:append:toolchain-clang16 = "${@bb.utils.contains("DISTRO_FEATURES", "usrmerge", " --dyld-prefix=/usr", "", d)}"
+
+TUNE_CCARGS:append:toolchain-clang16 = " -Qunused-arguments"
+
+LDFLAGS:append:toolchain-clang16:class-nativesdk:x86-64 = " -Wl,-dynamic-linker,${base_libdir}/ld-linux-x86-64.so.2"
+LDFLAGS:append:toolchain-clang16:class-nativesdk:x86 = " -Wl,-dynamic-linker,${base_libdir}/ld-linux.so.2"
+LDFLAGS:append:toolchain-clang16:class-nativesdk:aarch64 = " -Wl,-dynamic-linker,${base_libdir}/ld-linux-aarch64.so.1"
+
+LDFLAGS:toolchain-clang16:class-nativesdk = "${BUILDSDK_LDFLAGS} \
+                                           -Wl,-rpath-link,${STAGING_LIBDIR}/.. \
+                                           -Wl,-rpath,${libdir}/.. "
+
+# Enable lld globally"
+LDFLAGS:append:toolchain-clang16 = "${@bb.utils.contains('DISTRO_FEATURES', 'ld-is-lld', ' -fuse-ld=lld', '', d)}"
+
+# Remove gcc specific -fcanon-prefix-map option, added in gcc-13+
+# clang does not support it yet
+DEBUG_PREFIX_MAP:remove:toolchain-clang16 = "-fcanon-prefix-map"
+
+# choose between 'gcc' 'clang' an empty '' can be used as well
+TOOLCHAIN ??= "gcc"
+# choose between 'gnu' 'llvm'
+TC_CXX_RUNTIME ??= "gnu"
+# Using gcc or llvm runtime is only available when using clang for compiler
+#TC_CXX_RUNTIME:toolchain-gcc = "gnu"
+TC_CXX_RUNTIME:armeb = "gnu"
+TC_CXX_RUNTIME:armv5 = "gnu"
+
+TOOLCHAIN:class-native = "gcc"
+TOOLCHAIN:class-nativesdk = "gcc"
+TOOLCHAIN:class-cross-canadian = "gcc"
+TOOLCHAIN:class-crosssdk = "gcc"
+TOOLCHAIN:class-cross = "gcc"
+
+OVERRIDES =. "${@['', 'toolchain-${TOOLCHAIN}:']['${TOOLCHAIN}' != '']}"
+OVERRIDES =. "${@['', 'runtime-${TC_CXX_RUNTIME}:']['${TC_CXX_RUNTIME}' != '']}"
+OVERRIDES[vardepsexclude] += "TOOLCHAIN TC_CXX_RUNTIME"
+
+YOCTO_ALTERNATE_EXE_PATH:toolchain-clang16:class-target = "${STAGING_BINDIR}/llvm-config"
+YOCTO_ALTERNATE_LIBDIR:toolchain-clang16:class-target = "/${BASELIB}"
+
+#YOCTO_ALTERNATE_EXE_PATH:toolchain-clang16:class-target[export] = "1"
+#YOCTO_ALTERNATE_LIBDIR:toolchain-clang16:class-target[export] = "1"
+
+#DEPENDS:append:toolchain-clang16:class-target = " clang16-cross-${TARGET_ARCH} "
+#DEPENDS:remove:toolchain-clang16:allarch = "clang16-cross-${TARGET_ARCH}"
+
+def clang_base_deps(d):
+    if not d.getVar('INHIBIT_DEFAULT_DEPS', False):
+        if not oe.utils.inherits(d, 'allarch') :
+            ret = " ${MLPREFIX}clang16-cross-${TARGET_ARCH} virtual/libc "
+            if (d.getVar('TC_CXX_RUNTIME').find('android') != -1):
+                ret += " libcxx16-initial"
+                return ret
+            if (d.getVar('TC_CXX_RUNTIME').find('llvm') != -1):
+                ret += " compiler-rt16"
+            elif (d.getVar('COMPILER_RT').find('-rtlib=compiler-rt') != -1):
+                ret += " compiler-rt16 "
+            else:
+                ret += " libgcc "
+            if (d.getVar('TC_CXX_RUNTIME').find('llvm') != -1):
+                ret += " libcxx16-initial"
+            elif (d.getVar('COMPILER_RT').find('--unwindlib=libunwind') != -1):
+                ret += " libcxx16-initial "
+            elif (d.getVar('LIBCPLUSPLUS').find('-stdlib=libc++') != -1):
+                ret += " libcxx16-initial "
+            else:
+                ret += " virtual/${TARGET_PREFIX}compilerlibs "
+            return ret
+    return ""
+
+BASE_DEFAULT_DEPS:append:class-target:toolchain-clang16:class-target = " ${@clang_base_deps(d)}"
+BASE_DEFAULT_DEPS:append:class-native:toolchain-clang16:runtime-llvm = " libcxx16-initial-native compiler-rt16-native"
+BASE_DEFAULT_DEPS:append:class-nativesdk:toolchain-clang16:runtime-llvm = " clang16-native nativesdk-libcxx16-initial nativesdk-compiler-rt16"
+
+# do_populate_sysroot needs STRIP
+POPULATESYSROOTDEPS:toolchain-clang16:class-target = "${MLPREFIX}clang16-cross-${TARGET_ARCH}:do_populate_sysroot"
+
+cmake_do_generate_toolchain_file:append:toolchain-clang16 () {
+    cat >> ${WORKDIR}/toolchain.cmake <<EOF
+set( CMAKE_CLANG_TIDY ${HOST_PREFIX}clang-tidy )
+EOF
+    sed -i 's/ -mmusl / /g' ${WORKDIR}/toolchain.cmake
+}
+
+RECIPESYSROOTFUNCS = ""
+RECIPESYSROOTFUNCS:toolchain-clang16 = "recipe_sysroot_check_ld_is_lld"
+
+recipe_sysroot_check_ld_is_lld () {
+    if ${@bb.utils.contains('DISTRO_FEATURES', 'ld-is-lld', 'true', 'false', d)} &&  \
+        [ -e ${STAGING_BINDIR_TOOLCHAIN}/${TARGET_PREFIX}ld.lld ]; then
+        ln -srf ${STAGING_BINDIR_TOOLCHAIN}/${TARGET_PREFIX}ld.lld ${STAGING_BINDIR_TOOLCHAIN}/${TARGET_PREFIX}ld
+    fi
+}
+do_prepare_recipe_sysroot[postfuncs] += "${RECIPESYSROOTFUNCS}"
+#
+# dump recipes which still use gcc
+#python __anonymous() {
+#    toolchain = d.getVar("TOOLCHAIN")
+#    if not toolchain or toolchain == "clang" or 'class-target' not in d.getVar('OVERRIDES').split(':'):
+#        return
+#    pkgn = d.getVar("PN")
+#    bb.warn("%s - %s" % (pkgn, toolchain))
+#}

conf/layer.conf

@@ -34,6 +34,8 @@ INHERIT += "clang"
 CLANGSDK ??= "0"
 
 LLVMVERSION = "17.0.4"
+LLVM16VERSION = "16.0.6"
+LLVM15VERSION = "15.0.7"
 
 require conf/nonclangable.conf
 require conf/nonscanable.conf