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///===--- FileManager.cpp - File System Probing and Caching ----------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the FileManager interface.
//
//===----------------------------------------------------------------------===//
//
// TODO: This should index all interesting directories with dirent calls.
// getdirentries ?
// opendir/readdir_r/closedir ?
//
//===----------------------------------------------------------------------===//
#include "clang/Basic/FileManager.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/Bitcode/Serialize.h"
#include "llvm/Bitcode/Deserialize.h"
#include "llvm/Support/Streams.h"
using namespace clang;
// FIXME: Enhance libsystem to support inode and other fields.
#include <sys/stat.h>
#if defined(_MSC_VER)
#define S_ISDIR(s) (_S_IFDIR & s)
#endif
/// NON_EXISTENT_DIR - A special value distinct from null that is used to
/// represent a dir name that doesn't exist on the disk.
#define NON_EXISTENT_DIR reinterpret_cast<DirectoryEntry*>((intptr_t)-1)
/// getDirectory - Lookup, cache, and verify the specified directory. This
/// returns null if the directory doesn't exist.
///
const DirectoryEntry *FileManager::getDirectory(const char *NameStart,
const char *NameEnd) {
++NumDirLookups;
llvm::StringMapEntry<DirectoryEntry *> &NamedDirEnt =
DirEntries.GetOrCreateValue(NameStart, NameEnd);
// See if there is already an entry in the map.
if (NamedDirEnt.getValue())
return NamedDirEnt.getValue() == NON_EXISTENT_DIR
? 0 : NamedDirEnt.getValue();
++NumDirCacheMisses;
// By default, initialize it to invalid.
NamedDirEnt.setValue(NON_EXISTENT_DIR);
// Get the null-terminated directory name as stored as the key of the
// DirEntries map.
const char *InterndDirName = NamedDirEnt.getKeyData();
// Check to see if the directory exists.
struct stat StatBuf;
if (stat(InterndDirName, &StatBuf) || // Error stat'ing.
!S_ISDIR(StatBuf.st_mode)) // Not a directory?
return 0;
// It exists. See if we have already opened a directory with the same inode.
// This occurs when one dir is symlinked to another, for example.
DirectoryEntry &UDE =
UniqueDirs[std::make_pair(StatBuf.st_dev, StatBuf.st_ino)];
NamedDirEnt.setValue(&UDE);
if (UDE.getName()) // Already have an entry with this inode, return it.
return &UDE;
// Otherwise, we don't have this directory yet, add it. We use the string
// key from the DirEntries map as the string.
UDE.Name = InterndDirName;
return &UDE;
}
/// NON_EXISTENT_FILE - A special value distinct from null that is used to
/// represent a filename that doesn't exist on the disk.
#define NON_EXISTENT_FILE reinterpret_cast<FileEntry*>((intptr_t)-1)
/// getFile - Lookup, cache, and verify the specified file. This returns null
/// if the file doesn't exist.
///
const FileEntry *FileManager::getFile(const char *NameStart,
const char *NameEnd) {
++NumFileLookups;
// See if there is already an entry in the map.
llvm::StringMapEntry<FileEntry *> &NamedFileEnt =
FileEntries.GetOrCreateValue(NameStart, NameEnd);
// See if there is already an entry in the map.
if (NamedFileEnt.getValue())
return NamedFileEnt.getValue() == NON_EXISTENT_FILE
? 0 : NamedFileEnt.getValue();
++NumFileCacheMisses;
// By default, initialize it to invalid.
NamedFileEnt.setValue(NON_EXISTENT_FILE);
// Figure out what directory it is in. If the string contains a / in it,
// strip off everything after it.
// FIXME: this logic should be in sys::Path.
const char *SlashPos = NameEnd-1;
while (SlashPos >= NameStart && SlashPos[0] != '/')
--SlashPos;
const DirectoryEntry *DirInfo;
if (SlashPos < NameStart) {
// Use the current directory if file has no path component.
const char *Name = ".";
DirInfo = getDirectory(Name, Name+1);
} else if (SlashPos == NameEnd-1)
return 0; // If filename ends with a /, it's a directory.
else
DirInfo = getDirectory(NameStart, SlashPos);
if (DirInfo == 0) // Directory doesn't exist, file can't exist.
return 0;
// Get the null-terminated file name as stored as the key of the
// FileEntries map.
const char *InterndFileName = NamedFileEnt.getKeyData();
// FIXME: Use the directory info to prune this, before doing the stat syscall.
// FIXME: This will reduce the # syscalls.
// Nope, there isn't. Check to see if the file exists.
struct stat StatBuf;
//llvm::cerr << "STATING: " << Filename;
if (stat(InterndFileName, &StatBuf) || // Error stat'ing.
S_ISDIR(StatBuf.st_mode)) { // A directory?
// If this file doesn't exist, we leave a null in FileEntries for this path.
//llvm::cerr << ": Not existing\n";
return 0;
}
//llvm::cerr << ": exists\n";
// It exists. See if we have already opened a file with the same inode.
// This occurs when one dir is symlinked to another, for example.
FileEntry &UFE =
const_cast<FileEntry&>(*UniqueFiles.insert(FileEntry(StatBuf.st_dev,
StatBuf.st_ino)).first);
NamedFileEnt.setValue(&UFE);
if (UFE.getName()) // Already have an entry with this inode, return it.
return &UFE;
// Otherwise, we don't have this directory yet, add it.
// FIXME: Change the name to be a char* that points back to the 'FileEntries'
// key.
UFE.Name = InterndFileName;
UFE.Size = StatBuf.st_size;
UFE.ModTime = StatBuf.st_mtime;
UFE.Dir = DirInfo;
UFE.UID = NextFileUID++;
return &UFE;
}
void FileManager::PrintStats() const {
llvm::cerr << "\n*** File Manager Stats:\n";
llvm::cerr << UniqueFiles.size() << " files found, "
<< UniqueDirs.size() << " dirs found.\n";
llvm::cerr << NumDirLookups << " dir lookups, "
<< NumDirCacheMisses << " dir cache misses.\n";
llvm::cerr << NumFileLookups << " file lookups, "
<< NumFileCacheMisses << " file cache misses.\n";
//llvm::cerr << PagesMapped << BytesOfPagesMapped << FSLookups;
}
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