llvm-capstone/libcxx/include/float.h
Louis Dionne 5d87f60f89 [libc++] Only include_next C library headers when they exist
Some platforms don't provide all C library headers. In practice, libc++
only requires a few C library headers to exist, and only a few functions
on those headers. Missing functions that libc++ doesn't need for its own
implementation are handled properly by the using_if_exists attribute,
however a missing header is currently a hard error when we try to
do #include_next.

This patch should make libc++ more flexible on platforms that do not
provide C headers that libc++ doesn't actually require for its own
implementation. The only downside is that it may move some errors from
the #include_next point to later in the compilation if we actually try
to use something that isn't provided, which could be somewhat confusing.
However, these errors should be caught by folks trying to port libc++
over to a new platform (when running the libc++ test suite), not by end
users.

NOTE: This is a reapplicaton of 226409, which was reverted in 674729813
      because it broke the build. The issue has now been fixed with
      https://reviews.llvm.org/D138062.

Differential Revision: https://reviews.llvm.org/D136683
2022-11-17 10:30:20 -05:00

96 lines
1.6 KiB
C++

// -*- C++ -*-
//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef _LIBCPP_FLOAT_H
#define _LIBCPP_FLOAT_H
/*
float.h synopsis
Macros:
FLT_ROUNDS
FLT_EVAL_METHOD // C99
FLT_RADIX
FLT_MANT_DIG
DBL_MANT_DIG
LDBL_MANT_DIG
FLT_HAS_SUBNORM // C11
DBL_HAS_SUBNORM // C11
LDBL_HAS_SUBNORM // C11
DECIMAL_DIG // C99
FLT_DECIMAL_DIG // C11
DBL_DECIMAL_DIG // C11
LDBL_DECIMAL_DIG // C11
FLT_DIG
DBL_DIG
LDBL_DIG
FLT_MIN_EXP
DBL_MIN_EXP
LDBL_MIN_EXP
FLT_MIN_10_EXP
DBL_MIN_10_EXP
LDBL_MIN_10_EXP
FLT_MAX_EXP
DBL_MAX_EXP
LDBL_MAX_EXP
FLT_MAX_10_EXP
DBL_MAX_10_EXP
LDBL_MAX_10_EXP
FLT_MAX
DBL_MAX
LDBL_MAX
FLT_EPSILON
DBL_EPSILON
LDBL_EPSILON
FLT_MIN
DBL_MIN
LDBL_MIN
FLT_TRUE_MIN // C11
DBL_TRUE_MIN // C11
LDBL_TRUE_MIN // C11
*/
#include <__config>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
#endif
#if __has_include_next(<float.h>)
# include_next <float.h>
#endif
#ifdef __cplusplus
#ifndef FLT_EVAL_METHOD
#define FLT_EVAL_METHOD __FLT_EVAL_METHOD__
#endif
#ifndef DECIMAL_DIG
#define DECIMAL_DIG __DECIMAL_DIG__
#endif
#endif // __cplusplus
#endif // _LIBCPP_FLOAT_H