llvm-project/llvm/lib/System/Win32/Memory.inc

58 lines
1.8 KiB
C++

//===- Win32/Memory.cpp - Win32 Memory Implementation -----------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by Jeff Cohen and is distributed under the
// University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file provides the Win32 specific implementation of various Memory
// management utilities
//
//===----------------------------------------------------------------------===//
#include "Win32.h"
#include "llvm/System/Process.h"
namespace llvm {
using namespace sys;
//===----------------------------------------------------------------------===//
//=== WARNING: Implementation here must contain only Win32 specific code
//=== and must not be UNIX code
//===----------------------------------------------------------------------===//
MemoryBlock Memory::AllocateRWX(unsigned NumBytes,
const MemoryBlock *NearBlock,
std::string *ErrMsg) {
if (NumBytes == 0) return MemoryBlock();
static const long pageSize = Process::GetPageSize();
unsigned NumPages = (NumBytes+pageSize-1)/pageSize;
//FIXME: support NearBlock if ever needed on Win64.
void *pa = VirtualAlloc(NULL, NumPages*pageSize, MEM_COMMIT,
PAGE_EXECUTE_READWRITE);
if (pa == NULL) {
MakeErrMsg(ErrMsg, "Can't allocate RWX Memory: ");
return MemoryBlock();
}
MemoryBlock result;
result.Address = pa;
result.Size = NumPages*pageSize;
return result;
}
bool Memory::ReleaseRWX(MemoryBlock &M, std::string *ErrMsg) {
if (M.Address == 0 || M.Size == 0) return false;
if (!VirtualFree(M.Address, 0, MEM_RELEASE))
return MakeErrMsg(ErrMsg, "Can't release RWX Memory: ");
return false;
}
}