LLVM API Documentation
00001 //===- Win32/Memory.cpp - Win32 Memory Implementation -----------*- C++ -*-===// 00002 // 00003 // The LLVM Compiler Infrastructure 00004 // 00005 // This file was developed by Jeff Cohen and is distributed under the 00006 // University of Illinois Open Source License. See LICENSE.TXT for details. 00007 // 00008 //===----------------------------------------------------------------------===// 00009 // 00010 // This file provides the Win32 specific implementation of various Memory 00011 // management utilities 00012 // 00013 //===----------------------------------------------------------------------===// 00014 00015 #include "Win32.h" 00016 #include "llvm/System/Process.h" 00017 00018 namespace llvm { 00019 using namespace sys; 00020 00021 //===----------------------------------------------------------------------===// 00022 //=== WARNING: Implementation here must contain only Win32 specific code 00023 //=== and must not be UNIX code 00024 //===----------------------------------------------------------------------===// 00025 00026 MemoryBlock Memory::AllocateRWX(unsigned NumBytes, const MemoryBlock* NearBlock) { 00027 if (NumBytes == 0) return MemoryBlock(); 00028 00029 static const long pageSize = Process::GetPageSize(); 00030 unsigned NumPages = (NumBytes+pageSize-1)/pageSize; 00031 00032 //FIXME: support NearBlock if ever needed on Win64. 00033 00034 void *pa = VirtualAlloc(NULL, NumPages*pageSize, MEM_COMMIT, 00035 PAGE_EXECUTE_READWRITE); 00036 if (pa == NULL) { 00037 ThrowError("Can't allocate RWX Memory: "); 00038 } 00039 00040 MemoryBlock result; 00041 result.Address = pa; 00042 result.Size = NumPages*pageSize; 00043 return result; 00044 } 00045 00046 void Memory::ReleaseRWX(MemoryBlock& M) { 00047 if (M.Address == 0 || M.Size == 0) return; 00048 if (!VirtualFree(M.Address, 0, MEM_RELEASE)) { 00049 ThrowError("Can't release RWX Memory: "); 00050 } 00051 } 00052 00053 } 00054