libcxx: Facilitate building without llvm libunwind

when llvm unwind library is disabled, build was not picking up libgcc
automatically since we still use, compiler-rt for C runtime, therefore
introduce it via special CMAKE_SHARED_LINKER_FLAGS in packageconfig

Bundle static unwind library into libcxx-abi library and bundle
libcxx-abi.a into libc++.a this helps in just specifying lc++ and no
other flags are needed.

Also bundle static libunwind and cxx-abi but not into shared libc++, this would
avoid adding them explicitly on linker cmdline in packages when doing
static linking

Use PREFERRED_PROVIDER_libunwind to determine if unwind packageconfig
should be enabled or not

Pass -fno-exceptions on arm, otherwise it links in unwinding routines
which it expects to link from libgcc_s, we really don't need this when
doing cmake checks so disable exceptions during cmake checks

Signed-off-by: Khem Raj <raj.khem@gmail.com>

1 files changed, 15 insertions, 10 deletions

diff --git a/recipes-devtools/clang/libcxx_git.bb b/recipes-devtools/clang/libcxx_git.bb
index 2a2b5b7..e6e7e36 100644
--- a/recipes-devtools/clang/libcxx_git.bb
+++ b/recipes-devtools/clang/libcxx_git.bb
@@ -13,17 +13,16 @@ inherit cmake pythonnative
 DEPENDS += "ninja-native"
 BASEDEPENDS_remove_toolchain-clang = "libcxx"
 DEPENDS_append_toolchain-clang = " virtual/${TARGET_PREFIX}compilerlibs"
-TARGET_CXXFLAGS_remove_toolchain-clang = "--stdlib=libc++"
-TUNE_CCARGS_remove_toolchain-clang = "--rtlib=compiler-rt --unwindlib=libunwind --stdlib=libc++"
 
-LDFLAGS_append_toolchain-gcc = " -lgcc"
+TARGET_CXXFLAGS_remove_toolchain-clang = "--stdlib=libc++"
+TUNE_CCARGS_remove_toolchain-clang = "--unwindlib=libunwind --stdlib=libc++"
 
-PACKAGECONFIG ??= "unwind"
-PACKAGECONFIG_toolchain-gcc = ""
+PACKAGECONFIG ??= "${@bb.utils.contains('PREFERRED_PROVIDER_libunwind', 'libcxx', 'unwind', '', d)}"
 PACKAGECONFIG_powerpc = ""
 PACKAGECONFIG_riscv64 = ""
 PACKAGECONFIG_riscv32 = ""
-PACKAGECONFIG[unwind] = "-DLIBCXXABI_USE_LLVM_UNWINDER=ON -DLIBUNWIND_ENABLE_SHARED=ON -DLIBCXXABI_ENABLE_STATIC_UNWINDER=ON -DLIBCXXABI_LIBUNWIND_INCLUDES=${S}/projects/libunwind/include, -DLIBCXXABI_USE_LLVM_UNWINDER=OFF,"
+
+PACKAGECONFIG[unwind] = "-DLIBCXXABI_USE_LLVM_UNWINDER=ON -DLIBUNWIND_ENABLE_SHARED=ON -DLIBCXXABI_ENABLE_STATIC_UNWINDER=ON -DLIBCXXABI_STATICALLY_LINK_UNWINDER_IN_SHARED_LIBRARY=OFF -DLIBCXXABI_LIBUNWIND_INCLUDES=${S}/projects/libunwind/include, -DLIBCXXABI_USE_LLVM_UNWINDER=OFF -DCMAKE_SHARED_LINKER_FLAGS='-lgcc_s',"
 
 PROVIDES += "${@bb.utils.contains('PACKAGECONFIG', 'unwind', 'libunwind', '', d)}"
 LIBUNWIND = "${@bb.utils.contains('PACKAGECONFIG', 'unwind', ';libunwind', '', d)}"
@@ -34,14 +33,15 @@ LIC_FILES_CHKSUM = "file://libcxx/LICENSE.TXT;md5=55d89dd7eec8d3b4204b680e27da39
 "
 THUMB_TUNE_CCARGS = ""
 #TUNE_CCARGS += "-nostdlib"
-EXTRA_OECMAKE_append_armv5 = " -D_LIBCXXABI_HAS_ATOMIC_BUILTINS=OFF"
 
 EXTRA_OECMAKE += "\
+                  -DCMAKE_CROSSCOMPILING=ON \
                   -DLIBCXX_CXX_ABI=libcxxabi \
-                  -DLIBCXX_USE_COMPILER_RT=YES \
-                  -DLIBCXXABI_USE_COMPILER_RT=YES \
-                  -DCXX_SUPPORTS_CXX11=ON \
+                  -DLIBCXX_USE_COMPILER_RT=ON \
+                  -DLIBCXXABI_USE_COMPILER_RT=ON \
                   -DLIBCXX_INSTALL_EXPERIMENTAL_LIBRARY=ON \
+                  -DLIBCXX_ENABLE_STATIC_ABI_LIBRARY=ON \
+                  -DLIBCXX_STATICALLY_LINK_ABI_IN_SHARED_LIBRARY=OFF \
                   -DLIBCXXABI_LIBCXX_INCLUDES=${S}/libcxx/include \
                   -DLIBCXX_CXX_ABI_INCLUDE_PATHS=${S}/libcxxabi/include \
                   -DLIBCXX_CXX_ABI_LIBRARY_PATH=${B}/lib \
@@ -61,6 +61,11 @@ EXTRA_OECMAKE_append_riscv64 = " -DLIBCXXABI_ENABLE_EXCEPTIONS=ON \
                                  -DLIBOMP_LIBFLAGS='-latomic' \
                                  -DCMAKE_SHARED_LINKER_FLAGS='-lgcc_s -latomic' \
                                  "
+
+EXTRA_OECMAKE_append_armv5 = " -D_LIBCXXABI_HAS_ATOMIC_BUILTINS=OFF"
+
+EXTRA_OECMAKE_append_arm = " -DCMAKE_REQUIRED_FLAGS='-fno-exceptions'"
+
 EXTRA_OECMAKE_append_riscv32 = " -DLIBCXXABI_ENABLE_EXCEPTIONS=ON \
                                  -DLIBCXX_ENABLE_EXCEPTIONS=ON \
                                  -DLIBOMP_LIBFLAGS='-latomic' \