@@ -110,5 +110,39 @@ ifeq ($(BR2_TOOLCHAIN_EXTERNAL),y)
HOST_CLANG_CONF_OPTS += -DGCC_INSTALL_PREFIX:PATH=`realpath --relative-to=$(HOST_DIR)/bin/ $(TOOLCHAIN_EXTERNAL_INSTALL_DIR)`
endif
+define HOST_CLANG_INSTALL_WRAPPER_AND_SIMPLE_SYMLINKS
+ $(Q)cd $(HOST_DIR)/bin; \
+ for i in clang clang-$(CLANG_VERSION_MAJOR) clang++ clang-cl clang-cpp; do \
+ case "$$i" in \
+ *clang-$(CLANG_VERSION_MAJOR)) \
+ rm -f $$i.br_real; \
+ mv $$i $$i.br_real; \
+ ln -sf toolchain-wrapper-clang $$i; \
+ ;; \
+ *) \
+ ln -snf toolchain-wrapper-clang $$i; \
+ ln -snf clang-$(CLANG_VERSION_MAJOR).br_real $$i.br_real; \
+ ;; \
+ esac; \
+ done
+endef
+
+define HOST_CLANG_TOOLCHAIN_WRAPPER_BUILD
+ $(HOSTCC) $(HOST_CFLAGS) $(TOOLCHAIN_WRAPPER_ARGS) \
+ -s -Wl,--hash-style=$(TOOLCHAIN_WRAPPER_HASH_STYLE) \
+ toolchain/toolchain-wrapper.c \
+ -o $(@D)/toolchain-wrapper-clang
+endef
+
+define HOST_CLANG_TOOLCHAIN_WRAPPER_INSTALL
+ $(INSTALL) -D -m 0755 $(@D)/toolchain-wrapper-clang \
+ $(HOST_DIR)/bin/toolchain-wrapper-clang
+endef
+
+HOST_CLANG_TOOLCHAIN_WRAPPER_ARGS += -DBR_CROSS_PATH_SUFFIX='".br_real"'
+HOST_CLANG_POST_BUILD_HOOKS += HOST_CLANG_TOOLCHAIN_WRAPPER_BUILD
+HOST_CLANG_POST_INSTALL_HOOKS += HOST_CLANG_TOOLCHAIN_WRAPPER_INSTALL
+HOST_CLANG_POST_INSTALL_HOOKS += HOST_CLANG_INSTALL_WRAPPER_AND_SIMPLE_SYMLINKS
+
$(eval $(cmake-package))
$(eval $(host-cmake-package))
In order to use clang as a host cross-compiler for Buildroot, we need to provide at least the path to the sysroot (using --sysroot) and some other compiler flags. Hoppefully, we can reuse the toolchain wrapper for gcc since clang support most of the gcc flags used in the Buildroot's toolchain wrapper. Only the flag -mfused-madd (deprecated since gcc 4.6) for mips is not supported by clang. Since Clang require gcc >= 5.x this flag can never be used. Since host-clang is always build by Buildroot as an internal toolchain, we have to use a second toolchain-wrapper called toolchain-wrapper-clang when an external toolchain is used. Inded, the two wrapper use a different path BR_CROSS_PATH_SUFFIX in this case. After building the clang toolchain wrapper, create the symlinks needed to force package infrastructure to use clang througt the wrapper. Initially clang install the clang-8 binary and create all other symlinks: # clang -> clang-8 # clang++ -> clang # clang-8 # clang-cl -> clang # clang-cpp -> clang Use a post install hook to rename the clang-8 binary to clang-8.br_real and recreate all symlinks: # clang -> toolchain-wrapper-clang # clang++ -> toolchain-wrapper-clang # clang-8 -> toolchain-wrapper-clang # clang-8.br_real # clang++.br_real -> clang-8.br_real # clang.br_real -> clang-8.br_real # clang-cl -> toolchain-wrapper-clang # clang-cl.br_real -> clang-8.br_real # clang-cpp -> toolchain-wrapper-clang # clang-cpp.br_real -> clang-8.br_real Use the previously introduced CLANG_VERSION_MAJOR variable to create theses symlinks. Set BR_CROSS_PATH_SUFFIX to ".br_real" as for the Buildroot's internal GCC toolchain backend to find the "real" clang binary installed in $(HOST_DIR)/bin. Borrow TOOLCHAIN_WRAPPER_BUILD and TOOLCHAIN_WRAPPER_INSTALL to build and install the specific clang toolchain wrapper. Signed-off-by: Romain Naour <romain.naour@smile.fr> Cc: Matt Weber <matthew.weber@rockwellcollins.com> Cc: Valentin Korenblit <valentinkorenblit@gmail.com> --- package/clang/clang.mk | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+)