Files
clang-p2996/lldb/source/Host/windows/FileSystem.cpp
Greg Clayton 736888c84b Avoid crashing by not mmap'ing files on network mounted file systems.
This is implemented by making a new FileSystem function:

bool
FileSystem::IsLocal(const FileSpec &spec)

Then using this in a new function:

DataBufferSP
FileSpec::MemoryMapFileContentsIfLocal(off_t file_offset, size_t file_size) const;

This function only mmaps data if the file is a local file since that means we can reliably page in data. We were experiencing crashes where people would use debug info files on network mounted file systems and that mount would go away and cause the next access to a page that wasn't paged in to crash LLDB. 

We now avoid this by just copying the data into a heap buffer and keeping a permanent copy to avoid the crash. Updated all previous users of FileSpec::MemoryMapFileContentsIfLocal() in ObjectFile subclasses over to use the new FileSpec::MemoryMapFileContentsIfLocal() function.

<rdar://problem/19470249>

llvm-svn: 230283
2015-02-23 23:47:09 +00:00

153 lines
4.1 KiB
C++

//===-- FileSystem.cpp ------------------------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "lldb/Host/windows/windows.h"
#include <shellapi.h>
#include "lldb/Host/FileSystem.h"
using namespace lldb_private;
FileSpec::PathSyntax
FileSystem::GetNativePathSyntax()
{
return FileSpec::ePathSyntaxWindows;
}
Error
FileSystem::MakeDirectory(const char *path, uint32_t file_permissions)
{
// On Win32, the mode parameter is ignored, as Windows files and directories support a
// different permission model than POSIX.
Error error;
if (!::CreateDirectory(path, NULL) && GetLastError() != ERROR_ALREADY_EXISTS)
error.SetError(::GetLastError(), lldb::eErrorTypeWin32);
return error;
}
Error
FileSystem::DeleteDirectory(const char *path, bool recurse)
{
Error error;
if (!recurse)
{
BOOL result = ::RemoveDirectory(path);
if (!result)
error.SetError(::GetLastError(), lldb::eErrorTypeWin32);
}
else
{
// SHFileOperation() accepts a list of paths, and so must be double-null-terminated to
// indicate the end of the list.
std::string path_buffer(path);
path_buffer.push_back(0);
SHFILEOPSTRUCT shfos = {0};
shfos.wFunc = FO_DELETE;
shfos.pFrom = path_buffer.c_str();
shfos.fFlags = FOF_NO_UI;
int result = ::SHFileOperation(&shfos);
// TODO(zturner): Correctly handle the intricacies of SHFileOperation return values.
if (result != 0)
error.SetErrorStringWithFormat("SHFileOperation failed");
}
return error;
}
Error
FileSystem::GetFilePermissions(const char *path, uint32_t &file_permissions)
{
Error error;
error.SetErrorStringWithFormat("%s is not supported on this host", __PRETTY_FUNCTION__);
return error;
}
Error
FileSystem::SetFilePermissions(const char *path, uint32_t file_permissions)
{
Error error;
error.SetErrorStringWithFormat("%s is not supported on this host", __PRETTY_FUNCTION__);
return error;
}
lldb::user_id_t
FileSystem::GetFileSize(const FileSpec &file_spec)
{
return file_spec.GetByteSize();
}
bool
FileSystem::GetFileExists(const FileSpec &file_spec)
{
return file_spec.Exists();
}
Error
FileSystem::Symlink(const char *linkname, const char *target)
{
Error error;
DWORD attrib = ::GetFileAttributes(target);
if (attrib == INVALID_FILE_ATTRIBUTES)
{
error.SetError(::GetLastError(), lldb::eErrorTypeWin32);
return error;
}
bool is_directory = !!(attrib & FILE_ATTRIBUTE_DIRECTORY);
DWORD flag = is_directory ? SYMBOLIC_LINK_FLAG_DIRECTORY : 0;
BOOL result = ::CreateSymbolicLink(linkname, target, flag);
if (!result)
error.SetError(::GetLastError(), lldb::eErrorTypeWin32);
return error;
}
Error
FileSystem::Unlink(const char *path)
{
Error error;
BOOL result = ::DeleteFile(path);
if (!result)
error.SetError(::GetLastError(), lldb::eErrorTypeWin32);
return error;
}
Error
FileSystem::Readlink(const char *path, char *buf, size_t buf_len)
{
Error error;
HANDLE h = ::CreateFile(path, GENERIC_READ, FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, OPEN_EXISTING,
FILE_FLAG_OPEN_REPARSE_POINT, NULL);
if (h == INVALID_HANDLE_VALUE)
{
error.SetError(::GetLastError(), lldb::eErrorTypeWin32);
return error;
}
// Subtract 1 from the path length since this function does not add a null terminator.
DWORD result = ::GetFinalPathNameByHandle(h, buf, buf_len - 1, FILE_NAME_NORMALIZED | VOLUME_NAME_DOS);
if (result == 0)
error.SetError(::GetLastError(), lldb::eErrorTypeWin32);
::CloseHandle(h);
return error;
}
bool
FileSystem::IsLocal(const FileSpec &spec)
{
if (spec)
{
// TODO: return true if the file is on a locally mounted file system
return true;
}
return false;
}