1 //===- Win32/Memory.cpp - Win32 Memory Implementation -----------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file provides the Win32 specific implementation of various Memory
11 // management utilities
13 //===----------------------------------------------------------------------===//
16 #include "llvm/Support/DataTypes.h"
17 #include "llvm/Support/Process.h"
22 //===----------------------------------------------------------------------===//
23 //=== WARNING: Implementation here must contain only Win32 specific code
24 //=== and must not be UNIX code
25 //===----------------------------------------------------------------------===//
27 MemoryBlock Memory::AllocateRWX(size_t NumBytes,
28 const MemoryBlock *NearBlock,
29 std::string *ErrMsg) {
30 if (NumBytes == 0) return MemoryBlock();
32 static const size_t pageSize = Process::GetPageSize();
33 size_t NumPages = (NumBytes+pageSize-1)/pageSize;
35 //FIXME: support NearBlock if ever needed on Win64.
37 void *pa = VirtualAlloc(NULL, NumPages*pageSize, MEM_COMMIT,
38 PAGE_EXECUTE_READWRITE);
40 MakeErrMsg(ErrMsg, "Can't allocate RWX Memory: ");
46 result.Size = NumPages*pageSize;
50 bool 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: ");
57 static DWORD getProtection(const void *addr) {
58 MEMORY_BASIC_INFORMATION info;
59 if (sizeof(info) == ::VirtualQuery(addr, &info, sizeof(info))) {
65 bool Memory::setWritable(MemoryBlock &M, std::string *ErrMsg) {
66 if (!setRangeWritable(M.Address, M.Size)) {
67 return MakeErrMsg(ErrMsg, "Cannot set memory to writeable: ");
72 bool Memory::setExecutable(MemoryBlock &M, std::string *ErrMsg) {
73 if (!setRangeExecutable(M.Address, M.Size)) {
74 return MakeErrMsg(ErrMsg, "Cannot set memory to executable: ");
79 bool Memory::setRangeWritable(const void *Addr, size_t Size) {
80 DWORD prot = getProtection(Addr);
84 if (prot == PAGE_EXECUTE || prot == PAGE_EXECUTE_READ) {
85 prot = PAGE_EXECUTE_READWRITE;
86 } else if (prot == PAGE_NOACCESS || prot == PAGE_READONLY) {
87 prot = PAGE_READWRITE;
91 sys::Memory::InvalidateInstructionCache(Addr, Size);
92 return ::VirtualProtect(const_cast<LPVOID>(Addr), Size, prot, &oldProt)
96 bool Memory::setRangeExecutable(const void *Addr, size_t Size) {
97 DWORD prot = getProtection(Addr);
101 if (prot == PAGE_NOACCESS) {
103 } else if (prot == PAGE_READONLY) {
104 prot = PAGE_EXECUTE_READ;
105 } else if (prot == PAGE_READWRITE) {
106 prot = PAGE_EXECUTE_READWRITE;
110 sys::Memory::InvalidateInstructionCache(Addr, Size);
111 return ::VirtualProtect(const_cast<LPVOID>(Addr), Size, prot, &oldProt)