2010-11-24 03:19:34 +08:00
|
|
|
//===--- FileSystemStatCache.cpp - Caching for 'stat' calls ---------------===//
|
|
|
|
//
|
|
|
|
// The LLVM Compiler Infrastructure
|
|
|
|
//
|
|
|
|
// This file is distributed under the University of Illinois Open Source
|
|
|
|
// License. See LICENSE.TXT for details.
|
|
|
|
//
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
//
|
|
|
|
// This file defines the FileSystemStatCache interface.
|
|
|
|
//
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
|
|
|
|
#include "clang/Basic/FileSystemStatCache.h"
|
|
|
|
#include "llvm/System/Path.h"
|
2010-11-24 05:53:56 +08:00
|
|
|
|
|
|
|
// FIXME: This is terrible, we need this for ::close.
|
|
|
|
#if !defined(_MSC_VER) && !defined(__MINGW32__)
|
|
|
|
#include <unistd.h>
|
|
|
|
#include <sys/uio.h>
|
|
|
|
#else
|
|
|
|
#include <io.h>
|
|
|
|
#endif
|
2010-11-24 03:19:34 +08:00
|
|
|
using namespace clang;
|
|
|
|
|
2010-11-24 04:07:39 +08:00
|
|
|
#if defined(_MSC_VER)
|
|
|
|
#define S_ISDIR(s) (_S_IFDIR & s)
|
|
|
|
#endif
|
|
|
|
|
2010-11-24 05:17:56 +08:00
|
|
|
/// FileSystemStatCache::get - Get the 'stat' information for the specified
|
|
|
|
/// path, using the cache to accellerate it if possible. This returns true if
|
|
|
|
/// the path does not exist or false if it exists.
|
|
|
|
///
|
|
|
|
/// If FileDescriptor is non-null, then this lookup should only return success
|
|
|
|
/// for files (not directories). If it is null this lookup should only return
|
|
|
|
/// success for directories (not files). On a successful file lookup, the
|
|
|
|
/// implementation can optionally fill in FileDescriptor with a valid
|
|
|
|
/// descriptor and the client guarantees that it will close it.
|
|
|
|
bool FileSystemStatCache::get(const char *Path, struct stat &StatBuf,
|
|
|
|
int *FileDescriptor, FileSystemStatCache *Cache) {
|
|
|
|
LookupResult R;
|
|
|
|
|
|
|
|
if (Cache)
|
|
|
|
R = Cache->getStat(Path, StatBuf, FileDescriptor);
|
|
|
|
else
|
|
|
|
R = ::stat(Path, &StatBuf) != 0 ? CacheMissing : CacheExists;
|
|
|
|
|
2010-11-24 05:53:56 +08:00
|
|
|
// If the path doesn't exist, return failure.
|
2010-11-24 05:17:56 +08:00
|
|
|
if (R == CacheMissing) return true;
|
|
|
|
|
2010-11-24 05:53:56 +08:00
|
|
|
// If the path exists, make sure that its "directoryness" matches the clients
|
|
|
|
// demands.
|
2010-11-24 05:17:56 +08:00
|
|
|
bool isForDir = FileDescriptor == 0;
|
2010-11-24 05:53:56 +08:00
|
|
|
if (S_ISDIR(StatBuf.st_mode) != isForDir) {
|
|
|
|
// If not, close the file if opened.
|
|
|
|
if (FileDescriptor && *FileDescriptor != -1) {
|
|
|
|
::close(*FileDescriptor);
|
|
|
|
*FileDescriptor = -1;
|
|
|
|
}
|
|
|
|
|
|
|
|
return true;
|
|
|
|
}
|
|
|
|
|
|
|
|
return false;
|
2010-11-24 05:17:56 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
|
2010-11-24 03:19:34 +08:00
|
|
|
MemorizeStatCalls::LookupResult
|
2010-11-24 05:17:56 +08:00
|
|
|
MemorizeStatCalls::getStat(const char *Path, struct stat &StatBuf,
|
|
|
|
int *FileDescriptor) {
|
|
|
|
LookupResult Result = statChained(Path, StatBuf, FileDescriptor);
|
2010-11-24 03:19:34 +08:00
|
|
|
|
|
|
|
// Do not cache failed stats, it is easy to construct common inconsistent
|
|
|
|
// situations if we do, and they are not important for PCH performance (which
|
|
|
|
// currently only needs the stats to construct the initial FileManager
|
|
|
|
// entries).
|
2010-11-24 04:05:15 +08:00
|
|
|
if (Result == CacheMissing)
|
2010-11-24 03:19:34 +08:00
|
|
|
return Result;
|
|
|
|
|
|
|
|
// Cache file 'stat' results and directories with absolutely paths.
|
|
|
|
if (!S_ISDIR(StatBuf.st_mode) || llvm::sys::Path(Path).isAbsolute())
|
2010-11-24 03:28:12 +08:00
|
|
|
StatCalls[Path] = StatBuf;
|
2010-11-24 03:19:34 +08:00
|
|
|
|
|
|
|
return Result;
|
|
|
|
}
|