Build: Improve C++ support

Can choose the C++ standard (C++98/11/14/17/2a)
Can link with standard C++ library (libstdc++)
Add support of C++ exceptions
Add support of C++ RTTI
Add C++ options to subsys/cpp/Kconfig
Implements new and delete using k_malloc and k_free
if CONFIG_HEAP_MEM_POOL_SIZE is defined

Signed-off-by: Benoit Leforestier <benoit.leforestier@gmail.com>

subsys/cpp/CMakeLists.txt

@@ -4,4 +4,5 @@ zephyr_sources_ifdef(CONFIG_CPLUSPLUS
   cpp_init_array.c
   cpp_ctors.c
   cpp_dtors.c
+  cpp_new.cpp
 )

subsys/cpp/Kconfig

@@ -0,0 +1,70 @@
+# Kconfig - C++ configuration options
+
+#
+# Copyright (c) 2018 B. Leforestier
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+menu "C++ Options"
+
+config CPLUSPLUS
+	bool "Enable C++ support for the application"
+	help
+	  This option enables the use of applications built with C++.
+
+choice
+	prompt "C++ Standard"
+	default STD_CPP11
+	help
+	  C++ Standards.
+
+config STD_CPP98
+	bool "C++ 98"
+	help
+	  1998 C++ standard as modified by the 2003 technical corrigendum
+	  and some later defect reports.
+
+config STD_CPP11
+	bool "C++ 11"
+	help
+	  2011 C++ standard, previously known as C++0x.
+
+config STD_CPP14
+	bool "C++ 14"
+	help
+	  2014 C++ standard.
+
+config STD_CPP17
+	bool "C++ 17"
+	help
+	  2017 C++ standard, previously known as C++0x.
+
+config STD_CPP2A
+	bool "C++ 2a"
+	help
+	  Next revision of the C++ standard, which is expected to be published in 2020.
+
+endchoice
+
+config LIB_CPLUSPLUS
+	depends on CPLUSPLUS
+	bool "Link with STD C++ library"
+	help
+	  Link with STD C++ Library.
+
+config EXCEPTIONS
+	depends on CPLUSPLUS
+	select LIB_CPLUSPLUS
+	bool "Enable C++ exceptions support"
+	help
+	  This option enables support of C++ exceptions.
+
+config RTTI
+	depends on CPLUSPLUS
+	select LIB_CPLUSPLUS
+	bool "Enable C++ RTTI support"
+	help
+	  This option enables support of C++ RTTI.
+
+endmenu

subsys/cpp/cpp_new.cpp

@@ -0,0 +1,118 @@
+/*
+ * Copyright (c) 2018
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#if defined(CONFIG_LIB_CPLUSPLUS)
+#include <new>
+#endif // CONFIG_LIB_CPLUSPLUS
+#include <kernel.h>
+
+void* operator new(size_t size)
+{
+#if (CONFIG_HEAP_MEM_POOL_SIZE > 0)
+	void* ptr = k_malloc(size);
+#if defined(__cpp_exceptions) && defined(CONFIG_LIB_CPLUSPLUS)
+	if (!ptr)
+		throw std::bad_alloc();
+#endif
+	return ptr;
+#else
+	ARG_UNUSED(size);
+	return NULL;
+#endif
+}
+
+void* operator new[](size_t size)
+{
+#if (CONFIG_HEAP_MEM_POOL_SIZE > 0)
+	void* ptr = k_malloc(size);
+#if defined(__cpp_exceptions) && defined(CONFIG_LIB_CPLUSPLUS)
+	if (!ptr)
+		throw std::bad_alloc();
+#endif
+	return ptr;
+#else
+	ARG_UNUSED(size);
+	return NULL;
+#endif
+}
+
+void operator delete(void* ptr) noexcept
+{
+#if (CONFIG_HEAP_MEM_POOL_SIZE > 0)
+	k_free(ptr);
+#else
+	ARG_UNUSED(ptr);
+#endif
+}
+
+void operator delete[](void* ptr) noexcept
+{
+#if (CONFIG_HEAP_MEM_POOL_SIZE > 0)
+	k_free(ptr);
+#else
+	ARG_UNUSED(ptr);
+#endif
+}
+
+#if defined(CONFIG_LIB_CPLUSPLUS)
+void* operator new(size_t size, const std::nothrow_t&) noexcept
+{
+#if (CONFIG_HEAP_MEM_POOL_SIZE > 0)
+	return k_malloc(size);
+#else
+	ARG_UNUSED(size);
+	return NULL;
+#endif
+}
+
+void* operator new[](size_t size, const std::nothrow_t&) noexcept
+{
+#if (CONFIG_HEAP_MEM_POOL_SIZE > 0)
+	return k_malloc(size);
+#else
+	ARG_UNUSED(size);
+	return NULL;
+#endif
+}
+
+void operator delete(void* ptr, const std::nothrow_t&) noexcept
+{
+#if (CONFIG_HEAP_MEM_POOL_SIZE > 0)
+	k_free(ptr);
+#else
+	ARG_UNUSED(ptr);
+#endif
+}
+
+void operator delete[](void* ptr, const std::nothrow_t&) noexcept
+{
+#if (CONFIG_HEAP_MEM_POOL_SIZE > 0)
+	k_free(ptr);
+#else
+	ARG_UNUSED(ptr);
+#endif
+}
+#endif // CONFIG_LIB_CPLUSPLUS
+
+#if (__cplusplus > 201103L)
+void operator delete(void* ptr, size_t) noexcept
+{
+#if (CONFIG_HEAP_MEM_POOL_SIZE > 0)
+	k_free(ptr);
+#else
+	ARG_UNUSED(ptr);
+#endif
+}
+
+void operator delete[](void* ptr, size_t) noexcept
+{
+#if (CONFIG_HEAP_MEM_POOL_SIZE > 0)
+	k_free(ptr);
+#else
+	ARG_UNUSED(ptr);
+#endif
+}
+#endif // __cplusplus > 201103L