| //===-- 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__ |
