Memory.inc revision 218893 
1//===- Win32/Memory.cpp - Win32 Memory Implementation -----------*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file provides the Win32 specific implementation of various Memory
11// management utilities
12//
13//===----------------------------------------------------------------------===//
14
15#include "Windows.h"
16#include "llvm/Support/DataTypes.h"
17#include "llvm/Support/Process.h"
18
19namespace llvm {
20using namespace sys;
21
22//===----------------------------------------------------------------------===//
23//=== WARNING: Implementation here must contain only Win32 specific code
24//===          and must not be UNIX code
25//===----------------------------------------------------------------------===//
26
27MemoryBlock Memory::AllocateRWX(size_t NumBytes,
28                                const MemoryBlock *NearBlock,
29                                std::string *ErrMsg) {
30  if (NumBytes == 0) return MemoryBlock();
31
32  static const size_t pageSize = Process::GetPageSize();
33  size_t NumPages = (NumBytes+pageSize-1)/pageSize;
34
35  //FIXME: support NearBlock if ever needed on Win64.
36
37  void *pa = VirtualAlloc(NULL, NumPages*pageSize, MEM_COMMIT,
38                  PAGE_EXECUTE_READWRITE);
39  if (pa == NULL) {
40    MakeErrMsg(ErrMsg, "Can't allocate RWX Memory: ");
41    return MemoryBlock();
42  }
43
44  MemoryBlock result;
45  result.Address = pa;
46  result.Size = NumPages*pageSize;
47  return result;
48}
49
50bool Memory::ReleaseRWX(MemoryBlock &M, std::string *ErrMsg) {
51  if (M.Address == 0 || M.Size == 0) return false;
52  if (!VirtualFree(M.Address, 0, MEM_RELEASE))
53    return MakeErrMsg(ErrMsg, "Can't release RWX Memory: ");
54  return false;
55}
56
57bool Memory::setWritable(MemoryBlock &M, std::string *ErrMsg) {
58  return true;
59}
60
61bool Memory::setExecutable(MemoryBlock &M, std::string *ErrMsg) {
62  return false;
63}
64
65bool Memory::setRangeWritable(const void *Addr, size_t Size) {
66  return true;
67}
68
69bool Memory::setRangeExecutable(const void *Addr, size_t Size) {
70  return false;
71}
72
73}
74