32 lines
1.3 KiB
C++
32 lines
1.3 KiB
C++
//===-- MmapUtils.h ---------------------------------------------*- 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
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This file contains compatibility-related preprocessor directives related
|
|
// to mmap.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#ifdef __linux__
|
|
#include <sys/mman.h>
|
|
#include <sys/syscall.h>
|
|
|
|
// Before kernel 4.17, Linux did not support MAP_FIXED_NOREPLACE, so if it is
|
|
// not available, simplfy define it as MAP_FIXED which performs the same
|
|
// function but does not guarantee existing mappings won't get clobbered.
|
|
#ifndef MAP_FIXED_NOREPLACE
|
|
#define MAP_FIXED_NOREPLACE MAP_FIXED
|
|
#endif
|
|
|
|
// Some 32-bit architectures don't have mmap and define mmap2 instead. The only
|
|
// difference between the two syscalls is that mmap2's offset parameter is in
|
|
// terms 4096 byte offsets rather than individual bytes, so for our purposes
|
|
// they are effectively the same as all ofsets here are set to 0.
|
|
#if defined(SYS_mmap2) && !defined(SYS_mmap)
|
|
#define SYS_mmap SYS_mmap2
|
|
#endif
|
|
#endif // __linux__
|