clang: fix nativesdk build

I could not manage to build nativesdk-clang, I encountered errors as
follows: (trimmed for purpose)
| ../gcc/x86_64-pokysdk-linux/6.3.0/ld::
| cannot find crt1.o: No such file or directory
| cannot find crtbegin.o: No such file or directory
| cannot find -lgcc
| cannot find -lgcc_s

After some investigation, I found it's caused by the llvm native tools
could not compile with crosssdk toolchains. (special linking flags
are needed)

So we introduce a cmake-native class with a task to generate a native
toolchain file, it will be used to build llvm native tools by passed
with CROSS_TOOLCHAIN_FLAGS_NATIVE.

Signed-off-by: Ming Liu <peter.x.liu@external.atlascopco.com>
Signed-off-by: Khem Raj <raj.khem@gmail.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/recipes-devtools/clang/clang_git.bb b/recipes-devtools/clang/clang_git.bb
index fb7854c..c226093 100644
--- a/recipes-devtools/clang/clang_git.bb
+++ b/recipes-devtools/clang/clang_git.bb
@@ -27,7 +27,7 @@ INHIBIT_DEFAULT_DEPS = "1"
 
 S = "${WORKDIR}/git"
 
-inherit cmake
+inherit cmake cmake-native
 
 OECMAKE_FIND_ROOT_PATH_MODE_PROGRAM = "BOTH"
 
@@ -85,6 +85,7 @@ EXTRA_OECMAKE_append_class-native = "\
 "
 EXTRA_OECMAKE_append_class-nativesdk = "\
                   -DCMAKE_CROSSCOMPILING:BOOL=ON \
+                  -DCROSS_TOOLCHAIN_FLAGS_NATIVE='-DCMAKE_TOOLCHAIN_FILE=${WORKDIR}/toolchain-native.cmake' \
                   -DLLVM_TARGETS_TO_BUILD='${LLVM_TARGETS_TO_BUILD}' \
                   -DLLVM_TABLEGEN=${STAGING_BINDIR_NATIVE}/llvm-tblgen \
                   -DCLANG_TABLEGEN=${STAGING_BINDIR_NATIVE}/clang-tblgen \