// Copyright 2021 The Fuchsia Authors
//
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file or at
// https://opensource.org/licenses/MIT

#ifndef ZIRCON_KERNEL_LIB_KTL_INCLUDE___CONFIG_SITE_
#define ZIRCON_KERNEL_LIB_KTL_INCLUDE___CONFIG_SITE_

// The libc++ internal header <__config> does #include <__config_site> to get
// definitions that vary by operating system, machine, or configuration.  The
// toolchain's libc++ installation provides include/$triple/.../__config_site
// files for each $cpu-fuchsia appropriate for normal userland.  But the ktl
// abuse of libc++ is different from public userland libc++, so provide special
// kernel-appropriate definitions here.  This file will be in the include path
// ahead of any toolchain-supplied header.  Also, some special bare-metal build
// environments such as phys32 or efi that reuse ktl and kernel libc code may
// use settings that cause the compiler to change the $triple it injects into
// the include path to one for which no runtimes are built and so there is no
// __config_site file to be found at all.

// These two are what <__config_site> for Fuchsia userland defines.
#define _LIBCPP_ABI_VERSION 2
#define _LIBCPP_HAS_NO_VENDOR_AVAILABILITY_ANNOTATIONS 1

// This has to be defined to some `__*` string but what doesn't really matter.
#define _LIBCPP_ABI_NAMESPACE __ktl

// When compiling in the UEFI environment, the predefines look like Windows
// but there is no Windows runtime environment to use.
#define _LIBCPP_NO_VCRUNTIME 1

// This tells the headers not to use `extern template` declarations that
// expect specific instantiations/specializations to come from the libc++
// library rather than the headers.  In the kernel, only the headers are
// ever going to be available.
#define _LIBCPP_DISABLE_EXTERN_TEMPLATE 1

// This tells <atomic> not to use threading APIs.
#define _LIBCPP_HAS_NO_PLATFORM_WAIT 1

// This tells <atomic> et al to use <__external_threading> instead
// of expecting either POSIX or C11 threading APIs.
#define _LIBCPP_HAS_THREAD_API_EXTERNAL 1
#define _LIBCPP_HAS_THREAD_LIBRARY_EXTERNAL 1

// <__config> requires that these be set if _LIBCPP_HAS_THREAD_API_EXTERNAL is.
#define _LIBCPP_HAS_THREADS 1
#define _LIBCPP_HAS_MONOTONIC_CLOCK 1

// This tells <new> not to use `aligned_alloc` from <stdlib.h>.
#define _LIBCPP_HAS_NO_C11_ALIGNED_ALLOC 1

// This tells various headers to be strict about what includes what.
#define _LIBCPP_REMOVE_TRANSITIVE_INCLUDES 1

// This tells libc++ not to expect full locale APIs in some places.
#define _LIBCPP_HAS_NO_LOCALIZATION 1

// This is unfortunately required even though the kernel does not use wide
// characters.
#define _LIBCPP_HAS_WIDE_CHARACTERS 1

// This tells pstl headers to use serial algorithms and not try to
// do any multithreading.
#define _LIBCPP_PSTL_CPU_BACKEND_SERIAL 1

// This will probably never be used in code that ktl actually uses.
// But define it for completeness.
#define _LIBCPP_INSTRUMENTED_WITH_ASAN __has_feature(address_sanitizer)

// TODO(https://fxbug.dev/42082322): make the hardening mode selectable through build
// configurations.
// This sets the default to tell libc++ to not enable assertions to prevent
// undefined behavior, but may be overridden if _LIBCPP_HARDENING_MODE is
// defined elsewhere.
#define _LIBCPP_HARDENING_MODE_DEFAULT _LIBCPP_HARDENING_MODE_NONE

#define _LIBCPP_ASSERTION_SEMANTIC_DEFAULT _LIBCPP_ASSERTION_SEMANTIC_HARDENING_DEPENDENT

#endif  // ZIRCON_KERNEL_LIB_KTL_INCLUDE___CONFIG_SITE_