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 PVOID start = NearBlock ? static_cast<unsigned char *>(NearBlock->base()) +
36 NearBlock->size() : NULL;
38 void *pa = VirtualAlloc(start, NumPages*pageSize, MEM_RESERVE | MEM_COMMIT,
39 PAGE_EXECUTE_READWRITE);
42 // Try again without the NearBlock hint
43 return AllocateRWX(NumBytes, NULL, ErrMsg);
45 MakeErrMsg(ErrMsg, "Can't allocate RWX Memory: ");
51 result.Size = NumPages*pageSize;
55 bool Memory::ReleaseRWX(MemoryBlock &M, std::string *ErrMsg) {
56 if (M.Address == 0 || M.Size == 0) return false;
57 if (!VirtualFree(M.Address, 0, MEM_RELEASE))
58 return MakeErrMsg(ErrMsg, "Can't release RWX Memory: ");
62 static DWORD getProtection(const void *addr) {
63 MEMORY_BASIC_INFORMATION info;
64 if (sizeof(info) == ::VirtualQuery(addr, &info, sizeof(info))) {
70 bool Memory::setWritable(MemoryBlock &M, std::string *ErrMsg) {
71 if (!setRangeWritable(M.Address, M.Size)) {
72 return MakeErrMsg(ErrMsg, "Cannot set memory to writeable: ");
77 bool Memory::setExecutable(MemoryBlock &M, std::string *ErrMsg) {
78 if (!setRangeExecutable(M.Address, M.Size)) {
79 return MakeErrMsg(ErrMsg, "Cannot set memory to executable: ");
84 bool Memory::setRangeWritable(const void *Addr, size_t Size) {
85 DWORD prot = getProtection(Addr);
89 if (prot == PAGE_EXECUTE || prot == PAGE_EXECUTE_READ) {
90 prot = PAGE_EXECUTE_READWRITE;
91 } else if (prot == PAGE_NOACCESS || prot == PAGE_READONLY) {
92 prot = PAGE_READWRITE;
96 sys::Memory::InvalidateInstructionCache(Addr, Size);
97 return ::VirtualProtect(const_cast<LPVOID>(Addr), Size, prot, &oldProt)
101 bool Memory::setRangeExecutable(const void *Addr, size_t Size) {
102 DWORD prot = getProtection(Addr);
106 if (prot == PAGE_NOACCESS) {
108 } else if (prot == PAGE_READONLY) {
109 prot = PAGE_EXECUTE_READ;
110 } else if (prot == PAGE_READWRITE) {
111 prot = PAGE_EXECUTE_READWRITE;
115 sys::Memory::InvalidateInstructionCache(Addr, Size);
116 return ::VirtualProtect(const_cast<LPVOID>(Addr), Size, prot, &oldProt)