mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2025-10-30 16:17:05 +00:00
34cd4a484e
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50659 91177308-0d34-0410-b5e6-96231b3b80d8
77 lines
2.2 KiB
C++
77 lines
2.2 KiB
C++
//===- Unix/Memory.cpp - Generic UNIX System Configuration ------*- C++ -*-===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This file defines some functions for various memory management utilities.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "Unix.h"
|
|
#include "llvm/System/Process.h"
|
|
|
|
#ifdef HAVE_SYS_MMAN_H
|
|
#include <sys/mman.h>
|
|
#endif
|
|
|
|
/// AllocateRWXMemory - Allocate a slab of memory with read/write/execute
|
|
/// permissions. This is typically used for JIT applications where we want
|
|
/// to emit code to the memory then jump to it. Getting this type of memory
|
|
/// is very OS specific.
|
|
///
|
|
llvm::sys::MemoryBlock
|
|
llvm::sys::Memory::AllocateRWX(unsigned NumBytes, const MemoryBlock* NearBlock,
|
|
std::string *ErrMsg) {
|
|
if (NumBytes == 0) return MemoryBlock();
|
|
|
|
unsigned pageSize = Process::GetPageSize();
|
|
unsigned NumPages = (NumBytes+pageSize-1)/pageSize;
|
|
|
|
int fd = -1;
|
|
#ifdef NEED_DEV_ZERO_FOR_MMAP
|
|
static int zero_fd = open("/dev/zero", O_RDWR);
|
|
if (zero_fd == -1) {
|
|
MakeErrMsg(ErrMsg, "Can't open /dev/zero device");
|
|
return MemoryBlock();
|
|
}
|
|
fd = zero_fd;
|
|
#endif
|
|
|
|
int flags = MAP_PRIVATE |
|
|
#ifdef HAVE_MMAP_ANONYMOUS
|
|
MAP_ANONYMOUS
|
|
#else
|
|
MAP_ANON
|
|
#endif
|
|
;
|
|
|
|
void* start = NearBlock ? (unsigned char*)NearBlock->base() +
|
|
NearBlock->size() : 0;
|
|
|
|
void *pa = ::mmap(start, pageSize*NumPages, PROT_READ|PROT_WRITE|PROT_EXEC,
|
|
flags, fd, 0);
|
|
if (pa == MAP_FAILED) {
|
|
if (NearBlock) //Try again without a near hint
|
|
return AllocateRWX(NumBytes, 0);
|
|
|
|
MakeErrMsg(ErrMsg, "Can't allocate RWX Memory");
|
|
return MemoryBlock();
|
|
}
|
|
MemoryBlock result;
|
|
result.Address = pa;
|
|
result.Size = NumPages*pageSize;
|
|
return result;
|
|
}
|
|
|
|
bool llvm::sys::Memory::ReleaseRWX(MemoryBlock &M, std::string *ErrMsg) {
|
|
if (M.Address == 0 || M.Size == 0) return false;
|
|
if (0 != ::munmap(M.Address, M.Size))
|
|
return MakeErrMsg(ErrMsg, "Can't release RWX Memory");
|
|
return false;
|
|
}
|
|
|