libc:libxx: add new low level c++ standard library support

LLVM libc++abi is a new implementation of low level support for
a standard C++ library.

Change-Id: Ica9c81bd96fd27b169a06e352b0c394d47aed5b6

libs/libxx/.gitignore

@@ -1,3 +1,5 @@
 /uClibc++
 /libcxx
+/libcxxabi
 /libcxx-*.src.tar.xz
+/libcxxabi-*.src.tar.xz

libs/libxx/Kconfig

@@ -50,6 +50,25 @@ config UCLIBCXX
 
 endchoice
 
+choice
+	prompt "C++ low level library select"
+	default CXX_LIBSUPCXX
+
+config LIBCXXABI
+	bool "LLVM low level C++ Library"
+	---help---
+		LLVM "libc++abi" C++ Standard Library
+		https://libcxxabi.llvm.org/
+		Select if your use libc++abi as lower level c++ library
+
+config CXX_LIBSUPCXX
+	bool "GNU low level libsupc++"
+	---help---
+		Select if your toolchain provides libsupc++ and use libsupc++ as lower
+		level c++ library.
+
+endchoice
+
 config HAVE_CXXINITIALIZE
 	bool "Have C++ initialization"
 	default LIBCXX || UCLIBCXX
@@ -62,13 +81,6 @@ config CXX_EXCEPTION
 	bool "Enable Exception Support"
 	default LIBCXX || UCLIBCXX
 
-config CXX_LIBSUPCXX
-	bool "Have libsupc++ (required)"
-	default LIBCXX || UCLIBCXX
-	---help---
-		Select if your toolchain provides libsupc++.  This option is required
-		at present because the built-in libsupc++ support is incomplete.
-
 if UCLIBCXX
 
 config UCLIBCXX_BUFSIZE

libs/libxx/Makefile

@@ -45,6 +45,10 @@ else
 include cxx.defs
 endif
 
+ifeq ($(CONFIG_LIBCXXABI),y)
+include libcxxabi.defs
+endif
+
 # Object Files
 
 AOBJS = $(ASRCS:.S=$(OBJEXT))

libs/libxx/libcxxabi.defs

@@ -0,0 +1,54 @@
+############################################################################
+# libs/libxx/libcxxabi.defs
+#
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.  The
+# ASF licenses this file to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance with the
+# License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+# License for the specific language governing permissions and limitations
+# under the License.
+#
+###########################################################################
+
+VERSION=12.0.0
+
+libcxxabi-$(VERSION).src.tar.xz:
+	$(Q) curl -O -L https://github.com/llvm/llvm-project/releases/download/llvmorg-$(VERSION)/libcxxabi-$(VERSION).src.tar.xz
+
+libcxxabi: libcxxabi-$(VERSION).src.tar.xz
+	$(Q) tar -xf libcxxabi-$(VERSION).src.tar.xz
+	$(Q) mv libcxxabi-$(VERSION).src libcxxabi
+	$(Q) touch $@
+
+distclean::
+	$(Q) $(DELFILE) libcxxabi-$(VERSION).src.tar.xz
+	$(call DELDIR, libcxxabi)
+
+context:: libcxxabi
+
+# C++ABI files
+CPPSRCS += cxa_aux_runtime.cpp cxa_default_handlers.cpp cxa_demangle.cpp cxa_exception_storage.cpp
+CPPSRCS += cxa_guard.cpp cxa_handlers.cpp cxa_thread_atexit.cpp cxa_vector.cpp cxa_virtual.cpp
+# C++ STL files
+CPPSRCS += stdlib_exception.cpp stdlib_new_delete.cpp stdlib_stdexcept.cpp stdlib_typeinfo.cpp
+# Internal files
+CPPSRCS += abort_message.cpp fallback_malloc.cpp private_typeinfo.cpp
+
+ifeq ($(CONFIG_CXX_EXCEPTION), y)
+CXXFLAGS += ${shell $(DEFINE) "$(CC)" LIBCXXABI_ENABLE_EXCEPTIONS}
+CPPSRCS += cxa_exception.cpp cxa_personality.cpp
+else
+CPPSRCS += cxa_noexception.cpp
+endif
+
+DEPPATH += --dep-path libcxxabi/src
+VPATH += libcxxabi/src
+