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llvm-for-llvmta/include/llvm/Support/FileSystem.h

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//===- llvm/Support/FileSystem.h - File System OS Concept -------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file declares the llvm::sys::fs namespace. It is designed after
// TR2/boost filesystem (v3), but modified to remove exception handling and the
// path class.
//
// All functions return an error_code and their actual work via the last out
// argument. The out argument is defined if and only if errc::success is
// returned. A function may return any error code in the generic or system
// category. However, they shall be equivalent to any error conditions listed
// in each functions respective documentation if the condition applies. [ note:
// this does not guarantee that error_code will be in the set of explicitly
// listed codes, but it does guarantee that if any of the explicitly listed
// errors occur, the correct error_code will be used ]. All functions may
// return errc::not_enough_memory if there is not enough memory to complete the
// operation.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_SUPPORT_FILESYSTEM_H
#define LLVM_SUPPORT_FILESYSTEM_H
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/Twine.h"
#include "llvm/Config/llvm-config.h"
#include "llvm/Support/Chrono.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/ErrorOr.h"
#include "llvm/Support/FileSystem/UniqueID.h"
#include "llvm/Support/MD5.h"
#include <cassert>
#include <cstdint>
#include <ctime>
#include <memory>
#include <stack>
#include <string>
#include <system_error>
#include <vector>
#ifdef HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
namespace llvm {
namespace sys {
namespace fs {
#if defined(_WIN32)
// A Win32 HANDLE is a typedef of void*
using file_t = void *;
#else
using file_t = int;
#endif
extern const file_t kInvalidFile;
/// An enumeration for the file system's view of the type.
enum class file_type {
status_error,
file_not_found,
regular_file,
directory_file,
symlink_file,
block_file,
character_file,
fifo_file,
socket_file,
type_unknown
};
/// space_info - Self explanatory.
struct space_info {
uint64_t capacity;
uint64_t free;
uint64_t available;
};
enum perms {
no_perms = 0,
owner_read = 0400,
owner_write = 0200,
owner_exe = 0100,
owner_all = owner_read | owner_write | owner_exe,
group_read = 040,
group_write = 020,
group_exe = 010,
group_all = group_read | group_write | group_exe,
others_read = 04,
others_write = 02,
others_exe = 01,
others_all = others_read | others_write | others_exe,
all_read = owner_read | group_read | others_read,
all_write = owner_write | group_write | others_write,
all_exe = owner_exe | group_exe | others_exe,
all_all = owner_all | group_all | others_all,
set_uid_on_exe = 04000,
set_gid_on_exe = 02000,
sticky_bit = 01000,
all_perms = all_all | set_uid_on_exe | set_gid_on_exe | sticky_bit,
perms_not_known = 0xFFFF
};
// Helper functions so that you can use & and | to manipulate perms bits:
inline perms operator|(perms l, perms r) {
return static_cast<perms>(static_cast<unsigned short>(l) |
static_cast<unsigned short>(r));
}
inline perms operator&(perms l, perms r) {
return static_cast<perms>(static_cast<unsigned short>(l) &
static_cast<unsigned short>(r));
}
inline perms &operator|=(perms &l, perms r) {
l = l | r;
return l;
}
inline perms &operator&=(perms &l, perms r) {
l = l & r;
return l;
}
inline perms operator~(perms x) {
// Avoid UB by explicitly truncating the (unsigned) ~ result.
return static_cast<perms>(
static_cast<unsigned short>(~static_cast<unsigned short>(x)));
}
/// Represents the result of a call to directory_iterator::status(). This is a
/// subset of the information returned by a regular sys::fs::status() call, and
/// represents the information provided by Windows FileFirstFile/FindNextFile.
class basic_file_status {
protected:
#if defined(LLVM_ON_UNIX)
time_t fs_st_atime = 0;
time_t fs_st_mtime = 0;
uint32_t fs_st_atime_nsec = 0;
uint32_t fs_st_mtime_nsec = 0;
uid_t fs_st_uid = 0;
gid_t fs_st_gid = 0;
off_t fs_st_size = 0;
#elif defined (_WIN32)
uint32_t LastAccessedTimeHigh = 0;
uint32_t LastAccessedTimeLow = 0;
uint32_t LastWriteTimeHigh = 0;
uint32_t LastWriteTimeLow = 0;
uint32_t FileSizeHigh = 0;
uint32_t FileSizeLow = 0;
#endif
file_type Type = file_type::status_error;
perms Perms = perms_not_known;
public:
basic_file_status() = default;
explicit basic_file_status(file_type Type) : Type(Type) {}
#if defined(LLVM_ON_UNIX)
basic_file_status(file_type Type, perms Perms, time_t ATime,
uint32_t ATimeNSec, time_t MTime, uint32_t MTimeNSec,
uid_t UID, gid_t GID, off_t Size)
: fs_st_atime(ATime), fs_st_mtime(MTime),
fs_st_atime_nsec(ATimeNSec), fs_st_mtime_nsec(MTimeNSec),
fs_st_uid(UID), fs_st_gid(GID),
fs_st_size(Size), Type(Type), Perms(Perms) {}
#elif defined(_WIN32)
basic_file_status(file_type Type, perms Perms, uint32_t LastAccessTimeHigh,
uint32_t LastAccessTimeLow, uint32_t LastWriteTimeHigh,
uint32_t LastWriteTimeLow, uint32_t FileSizeHigh,
uint32_t FileSizeLow)
: LastAccessedTimeHigh(LastAccessTimeHigh),
LastAccessedTimeLow(LastAccessTimeLow),
LastWriteTimeHigh(LastWriteTimeHigh),
LastWriteTimeLow(LastWriteTimeLow), FileSizeHigh(FileSizeHigh),
FileSizeLow(FileSizeLow), Type(Type), Perms(Perms) {}
#endif
// getters
file_type type() const { return Type; }
perms permissions() const { return Perms; }
/// The file access time as reported from the underlying file system.
///
/// Also see comments on \c getLastModificationTime() related to the precision
/// of the returned value.
TimePoint<> getLastAccessedTime() const;
/// The file modification time as reported from the underlying file system.
///
/// The returned value allows for nanosecond precision but the actual
/// resolution is an implementation detail of the underlying file system.
/// There is no guarantee for what kind of resolution you can expect, the
/// resolution can differ across platforms and even across mountpoints on the
/// same machine.
TimePoint<> getLastModificationTime() const;
#if defined(LLVM_ON_UNIX)
uint32_t getUser() const { return fs_st_uid; }
uint32_t getGroup() const { return fs_st_gid; }
uint64_t getSize() const { return fs_st_size; }
#elif defined (_WIN32)
uint32_t getUser() const {
return 9999; // Not applicable to Windows, so...
}
uint32_t getGroup() const {
return 9999; // Not applicable to Windows, so...
}
uint64_t getSize() const {
return (uint64_t(FileSizeHigh) << 32) + FileSizeLow;
}
#endif
// setters
void type(file_type v) { Type = v; }
void permissions(perms p) { Perms = p; }
};
/// Represents the result of a call to sys::fs::status().
class file_status : public basic_file_status {
friend bool equivalent(file_status A, file_status B);
#if defined(LLVM_ON_UNIX)
dev_t fs_st_dev = 0;
nlink_t fs_st_nlinks = 0;
ino_t fs_st_ino = 0;
#elif defined (_WIN32)
uint32_t NumLinks = 0;
uint32_t VolumeSerialNumber = 0;
uint32_t FileIndexHigh = 0;
uint32_t FileIndexLow = 0;
#endif
public:
file_status() = default;
explicit file_status(file_type Type) : basic_file_status(Type) {}
#if defined(LLVM_ON_UNIX)
file_status(file_type Type, perms Perms, dev_t Dev, nlink_t Links, ino_t Ino,
time_t ATime, uint32_t ATimeNSec,
time_t MTime, uint32_t MTimeNSec,
uid_t UID, gid_t GID, off_t Size)
: basic_file_status(Type, Perms, ATime, ATimeNSec, MTime, MTimeNSec,
UID, GID, Size),
fs_st_dev(Dev), fs_st_nlinks(Links), fs_st_ino(Ino) {}
#elif defined(_WIN32)
file_status(file_type Type, perms Perms, uint32_t LinkCount,
uint32_t LastAccessTimeHigh, uint32_t LastAccessTimeLow,
uint32_t LastWriteTimeHigh, uint32_t LastWriteTimeLow,
uint32_t VolumeSerialNumber, uint32_t FileSizeHigh,
uint32_t FileSizeLow, uint32_t FileIndexHigh,
uint32_t FileIndexLow)
: basic_file_status(Type, Perms, LastAccessTimeHigh, LastAccessTimeLow,
LastWriteTimeHigh, LastWriteTimeLow, FileSizeHigh,
FileSizeLow),
NumLinks(LinkCount), VolumeSerialNumber(VolumeSerialNumber),
FileIndexHigh(FileIndexHigh), FileIndexLow(FileIndexLow) {}
#endif
UniqueID getUniqueID() const;
uint32_t getLinkCount() const;
};
/// @}
/// @name Physical Operators
/// @{
/// Make \a path an absolute path.
///
/// Makes \a path absolute using the \a current_directory if it is not already.
/// An empty \a path will result in the \a current_directory.
///
/// /absolute/path => /absolute/path
/// relative/../path => <current-directory>/relative/../path
///
/// @param path A path that is modified to be an absolute path.
void make_absolute(const Twine &current_directory, SmallVectorImpl<char> &path);
/// Make \a path an absolute path.
///
/// Makes \a path absolute using the current directory if it is not already. An
/// empty \a path will result in the current directory.
///
/// /absolute/path => /absolute/path
/// relative/../path => <current-directory>/relative/../path
///
/// @param path A path that is modified to be an absolute path.
/// @returns errc::success if \a path has been made absolute, otherwise a
/// platform-specific error_code.
std::error_code make_absolute(SmallVectorImpl<char> &path);
/// Create all the non-existent directories in path.
///
/// @param path Directories to create.
/// @returns errc::success if is_directory(path), otherwise a platform
/// specific error_code. If IgnoreExisting is false, also returns
/// error if the directory already existed.
std::error_code create_directories(const Twine &path,
bool IgnoreExisting = true,
perms Perms = owner_all | group_all);
/// Create the directory in path.
///
/// @param path Directory to create.
/// @returns errc::success if is_directory(path), otherwise a platform
/// specific error_code. If IgnoreExisting is false, also returns
/// error if the directory already existed.
std::error_code create_directory(const Twine &path, bool IgnoreExisting = true,
perms Perms = owner_all | group_all);
/// Create a link from \a from to \a to.
///
/// The link may be a soft or a hard link, depending on the platform. The caller
/// may not assume which one. Currently on windows it creates a hard link since
/// soft links require extra privileges. On unix, it creates a soft link since
/// hard links don't work on SMB file systems.
///
/// @param to The path to hard link to.
/// @param from The path to hard link from. This is created.
/// @returns errc::success if the link was created, otherwise a platform
/// specific error_code.
std::error_code create_link(const Twine &to, const Twine &from);
/// Create a hard link from \a from to \a to, or return an error.
///
/// @param to The path to hard link to.
/// @param from The path to hard link from. This is created.
/// @returns errc::success if the link was created, otherwise a platform
/// specific error_code.
std::error_code create_hard_link(const Twine &to, const Twine &from);
/// Collapse all . and .. patterns, resolve all symlinks, and optionally
/// expand ~ expressions to the user's home directory.
///
/// @param path The path to resolve.
/// @param output The location to store the resolved path.
/// @param expand_tilde If true, resolves ~ expressions to the user's home
/// directory.
std::error_code real_path(const Twine &path, SmallVectorImpl<char> &output,
bool expand_tilde = false);
/// Expands ~ expressions to the user's home directory. On Unix ~user
/// directories are resolved as well.
///
/// @param path The path to resolve.
void expand_tilde(const Twine &path, SmallVectorImpl<char> &output);
/// Get the current path.
///
/// @param result Holds the current path on return.
/// @returns errc::success if the current path has been stored in result,
/// otherwise a platform-specific error_code.
std::error_code current_path(SmallVectorImpl<char> &result);
/// Set the current path.
///
/// @param path The path to set.
/// @returns errc::success if the current path was successfully set,
/// otherwise a platform-specific error_code.
std::error_code set_current_path(const Twine &path);
/// Remove path. Equivalent to POSIX remove().
///
/// @param path Input path.
/// @returns errc::success if path has been removed or didn't exist, otherwise a
/// platform-specific error code. If IgnoreNonExisting is false, also
/// returns error if the file didn't exist.
std::error_code remove(const Twine &path, bool IgnoreNonExisting = true);
/// Recursively delete a directory.
///
/// @param path Input path.
/// @returns errc::success if path has been removed or didn't exist, otherwise a
/// platform-specific error code.
std::error_code remove_directories(const Twine &path, bool IgnoreErrors = true);
/// Rename \a from to \a to.
///
/// Files are renamed as if by POSIX rename(), except that on Windows there may
/// be a short interval of time during which the destination file does not
/// exist.
///
/// @param from The path to rename from.
/// @param to The path to rename to. This is created.
std::error_code rename(const Twine &from, const Twine &to);
/// Copy the contents of \a From to \a To.
///
/// @param From The path to copy from.
/// @param To The path to copy to. This is created.
std::error_code copy_file(const Twine &From, const Twine &To);
/// Copy the contents of \a From to \a To.
///
/// @param From The path to copy from.
/// @param ToFD The open file descriptor of the destination file.
std::error_code copy_file(const Twine &From, int ToFD);
/// Resize path to size. File is resized as if by POSIX truncate().
///
/// @param FD Input file descriptor.
/// @param Size Size to resize to.
/// @returns errc::success if \a path has been resized to \a size, otherwise a
/// platform-specific error_code.
std::error_code resize_file(int FD, uint64_t Size);
/// Compute an MD5 hash of a file's contents.
///
/// @param FD Input file descriptor.
/// @returns An MD5Result with the hash computed, if successful, otherwise a
/// std::error_code.
ErrorOr<MD5::MD5Result> md5_contents(int FD);
/// Version of compute_md5 that doesn't require an open file descriptor.
ErrorOr<MD5::MD5Result> md5_contents(const Twine &Path);
/// @}
/// @name Physical Observers
/// @{
/// Does file exist?
///
/// @param status A basic_file_status previously returned from stat.
/// @returns True if the file represented by status exists, false if it does
/// not.
bool exists(const basic_file_status &status);
enum class AccessMode { Exist, Write, Execute };
/// Can the file be accessed?
///
/// @param Path Input path.
/// @returns errc::success if the path can be accessed, otherwise a
/// platform-specific error_code.
std::error_code access(const Twine &Path, AccessMode Mode);
/// Does file exist?
///
/// @param Path Input path.
/// @returns True if it exists, false otherwise.
inline bool exists(const Twine &Path) {
return !access(Path, AccessMode::Exist);
}
/// Can we execute this file?
///
/// @param Path Input path.
/// @returns True if we can execute it, false otherwise.
bool can_execute(const Twine &Path);
/// Can we write this file?
///
/// @param Path Input path.
/// @returns True if we can write to it, false otherwise.
inline bool can_write(const Twine &Path) {
return !access(Path, AccessMode::Write);
}
/// Do file_status's represent the same thing?
///
/// @param A Input file_status.
/// @param B Input file_status.
///
/// assert(status_known(A) || status_known(B));
///
/// @returns True if A and B both represent the same file system entity, false
/// otherwise.
bool equivalent(file_status A, file_status B);
/// Do paths represent the same thing?
///
/// assert(status_known(A) || status_known(B));
///
/// @param A Input path A.
/// @param B Input path B.
/// @param result Set to true if stat(A) and stat(B) have the same device and
/// inode (or equivalent).
/// @returns errc::success if result has been successfully set, otherwise a
/// platform-specific error_code.
std::error_code equivalent(const Twine &A, const Twine &B, bool &result);
/// Simpler version of equivalent for clients that don't need to
/// differentiate between an error and false.
inline bool equivalent(const Twine &A, const Twine &B) {
bool result;
return !equivalent(A, B, result) && result;
}
/// Is the file mounted on a local filesystem?
///
/// @param path Input path.
/// @param result Set to true if \a path is on fixed media such as a hard disk,
/// false if it is not.
/// @returns errc::success if result has been successfully set, otherwise a
/// platform specific error_code.
std::error_code is_local(const Twine &path, bool &result);
/// Version of is_local accepting an open file descriptor.
std::error_code is_local(int FD, bool &result);
/// Simpler version of is_local for clients that don't need to
/// differentiate between an error and false.
inline bool is_local(const Twine &Path) {
bool Result;
return !is_local(Path, Result) && Result;
}
/// Simpler version of is_local accepting an open file descriptor for
/// clients that don't need to differentiate between an error and false.
inline bool is_local(int FD) {
bool Result;
return !is_local(FD, Result) && Result;
}
/// Does status represent a directory?
///
/// @param Path The path to get the type of.
/// @param Follow For symbolic links, indicates whether to return the file type
/// of the link itself, or of the target.
/// @returns A value from the file_type enumeration indicating the type of file.
file_type get_file_type(const Twine &Path, bool Follow = true);
/// Does status represent a directory?
///
/// @param status A basic_file_status previously returned from status.
/// @returns status.type() == file_type::directory_file.
bool is_directory(const basic_file_status &status);
/// Is path a directory?
///
/// @param path Input path.
/// @param result Set to true if \a path is a directory (after following
/// symlinks, false if it is not. Undefined otherwise.
/// @returns errc::success if result has been successfully set, otherwise a
/// platform-specific error_code.
std::error_code is_directory(const Twine &path, bool &result);
/// Simpler version of is_directory for clients that don't need to
/// differentiate between an error and false.
inline bool is_directory(const Twine &Path) {
bool Result;
return !is_directory(Path, Result) && Result;
}
/// Does status represent a regular file?
///
/// @param status A basic_file_status previously returned from status.
/// @returns status_known(status) && status.type() == file_type::regular_file.
bool is_regular_file(const basic_file_status &status);
/// Is path a regular file?
///
/// @param path Input path.
/// @param result Set to true if \a path is a regular file (after following
/// symlinks), false if it is not. Undefined otherwise.
/// @returns errc::success if result has been successfully set, otherwise a
/// platform-specific error_code.
std::error_code is_regular_file(const Twine &path, bool &result);
/// Simpler version of is_regular_file for clients that don't need to
/// differentiate between an error and false.
inline bool is_regular_file(const Twine &Path) {
bool Result;
if (is_regular_file(Path, Result))
return false;
return Result;
}
/// Does status represent a symlink file?
///
/// @param status A basic_file_status previously returned from status.
/// @returns status_known(status) && status.type() == file_type::symlink_file.
bool is_symlink_file(const basic_file_status &status);
/// Is path a symlink file?
///
/// @param path Input path.
/// @param result Set to true if \a path is a symlink file, false if it is not.
/// Undefined otherwise.
/// @returns errc::success if result has been successfully set, otherwise a
/// platform-specific error_code.
std::error_code is_symlink_file(const Twine &path, bool &result);
/// Simpler version of is_symlink_file for clients that don't need to
/// differentiate between an error and false.
inline bool is_symlink_file(const Twine &Path) {
bool Result;
if (is_symlink_file(Path, Result))
return false;
return Result;
}
/// Does this status represent something that exists but is not a
/// directory or regular file?
///
/// @param status A basic_file_status previously returned from status.
/// @returns exists(s) && !is_regular_file(s) && !is_directory(s)
bool is_other(const basic_file_status &status);
/// Is path something that exists but is not a directory,
/// regular file, or symlink?
///
/// @param path Input path.
/// @param result Set to true if \a path exists, but is not a directory, regular
/// file, or a symlink, false if it does not. Undefined otherwise.
/// @returns errc::success if result has been successfully set, otherwise a
/// platform-specific error_code.
std::error_code is_other(const Twine &path, bool &result);
/// Get file status as if by POSIX stat().
///
/// @param path Input path.
/// @param result Set to the file status.
/// @param follow When true, follows symlinks. Otherwise, the symlink itself is
/// statted.
/// @returns errc::success if result has been successfully set, otherwise a
/// platform-specific error_code.
std::error_code status(const Twine &path, file_status &result,
bool follow = true);
/// A version for when a file descriptor is already available.
std::error_code status(int FD, file_status &Result);
#ifdef _WIN32
/// A version for when a file descriptor is already available.
std::error_code status(file_t FD, file_status &Result);
#endif
/// Get file creation mode mask of the process.
///
/// @returns Mask reported by umask(2)
/// @note There is no umask on Windows. This function returns 0 always
/// on Windows. This function does not return an error_code because
/// umask(2) never fails. It is not thread safe.
unsigned getUmask();
/// Set file permissions.
///
/// @param Path File to set permissions on.
/// @param Permissions New file permissions.
/// @returns errc::success if the permissions were successfully set, otherwise
/// a platform-specific error_code.
/// @note On Windows, all permissions except *_write are ignored. Using any of
/// owner_write, group_write, or all_write will make the file writable.
/// Otherwise, the file will be marked as read-only.
std::error_code setPermissions(const Twine &Path, perms Permissions);
/// Vesion of setPermissions accepting a file descriptor.
/// TODO Delete the path based overload once we implement the FD based overload
/// on Windows.
std::error_code setPermissions(int FD, perms Permissions);
/// Get file permissions.
///
/// @param Path File to get permissions from.
/// @returns the permissions if they were successfully retrieved, otherwise a
/// platform-specific error_code.
/// @note On Windows, if the file does not have the FILE_ATTRIBUTE_READONLY
/// attribute, all_all will be returned. Otherwise, all_read | all_exe
/// will be returned.
ErrorOr<perms> getPermissions(const Twine &Path);
/// Get file size.
///
/// @param Path Input path.
/// @param Result Set to the size of the file in \a Path.
/// @returns errc::success if result has been successfully set, otherwise a
/// platform-specific error_code.
inline std::error_code file_size(const Twine &Path, uint64_t &Result) {
file_status Status;
std::error_code EC = status(Path, Status);
if (EC)
return EC;
Result = Status.getSize();
return std::error_code();
}
/// Set the file modification and access time.
///
/// @returns errc::success if the file times were successfully set, otherwise a
/// platform-specific error_code or errc::function_not_supported on
/// platforms where the functionality isn't available.
std::error_code setLastAccessAndModificationTime(int FD, TimePoint<> AccessTime,
TimePoint<> ModificationTime);
/// Simpler version that sets both file modification and access time to the same
/// time.
inline std::error_code setLastAccessAndModificationTime(int FD,
TimePoint<> Time) {
return setLastAccessAndModificationTime(FD, Time, Time);
}
/// Is status available?
///
/// @param s Input file status.
/// @returns True if status() != status_error.
bool status_known(const basic_file_status &s);
/// Is status available?
///
/// @param path Input path.
/// @param result Set to true if status() != status_error.
/// @returns errc::success if result has been successfully set, otherwise a
/// platform-specific error_code.
std::error_code status_known(const Twine &path, bool &result);
enum CreationDisposition : unsigned {
/// CD_CreateAlways - When opening a file:
/// * If it already exists, truncate it.
/// * If it does not already exist, create a new file.
CD_CreateAlways = 0,
/// CD_CreateNew - When opening a file:
/// * If it already exists, fail.
/// * If it does not already exist, create a new file.
CD_CreateNew = 1,
/// CD_OpenExisting - When opening a file:
/// * If it already exists, open the file with the offset set to 0.
/// * If it does not already exist, fail.
CD_OpenExisting = 2,
/// CD_OpenAlways - When opening a file:
/// * If it already exists, open the file with the offset set to 0.
/// * If it does not already exist, create a new file.
CD_OpenAlways = 3,
};
enum FileAccess : unsigned {
FA_Read = 1,
FA_Write = 2,
};
enum OpenFlags : unsigned {
OF_None = 0,
F_None = 0, // For compatibility
/// The file should be opened in text mode on platforms that make this
/// distinction.
OF_Text = 1,
F_Text = 1, // For compatibility
/// The file should be opened in append mode.
OF_Append = 2,
F_Append = 2, // For compatibility
/// Delete the file on close. Only makes a difference on windows.
OF_Delete = 4,
/// When a child process is launched, this file should remain open in the
/// child process.
OF_ChildInherit = 8,
/// Force files Atime to be updated on access. Only makes a difference on windows.
OF_UpdateAtime = 16,
};
/// Create a potentially unique file name but does not create it.
///
/// Generates a unique path suitable for a temporary file but does not
/// open or create the file. The name is based on \a Model with '%'
/// replaced by a random char in [0-9a-f]. If \a MakeAbsolute is true
/// then the system's temp directory is prepended first. If \a MakeAbsolute
/// is false the current directory will be used instead.
///
/// This function does not check if the file exists. If you want to be sure
/// that the file does not yet exist, you should use use enough '%' characters
/// in your model to ensure this. Each '%' gives 4-bits of entropy so you can
/// use 32 of them to get 128 bits of entropy.
///
/// Example: clang-%%-%%-%%-%%-%%.s => clang-a0-b1-c2-d3-e4.s
///
/// @param Model Name to base unique path off of.
/// @param ResultPath Set to the file's path.
/// @param MakeAbsolute Whether to use the system temp directory.
void createUniquePath(const Twine &Model, SmallVectorImpl<char> &ResultPath,
bool MakeAbsolute);
/// Create a uniquely named file.
///
/// Generates a unique path suitable for a temporary file and then opens it as a
/// file. The name is based on \a Model with '%' replaced by a random char in
/// [0-9a-f]. If \a Model is not an absolute path, the temporary file will be
/// created in the current directory.
///
/// Example: clang-%%-%%-%%-%%-%%.s => clang-a0-b1-c2-d3-e4.s
///
/// This is an atomic operation. Either the file is created and opened, or the
/// file system is left untouched.
///
/// The intended use is for files that are to be kept, possibly after
/// renaming them. For example, when running 'clang -c foo.o', the file can
/// be first created as foo-abc123.o and then renamed.
///
/// @param Model Name to base unique path off of.
/// @param ResultFD Set to the opened file's file descriptor.
/// @param ResultPath Set to the opened file's absolute path.
/// @returns errc::success if Result{FD,Path} have been successfully set,
/// otherwise a platform-specific error_code.
std::error_code createUniqueFile(const Twine &Model, int &ResultFD,
SmallVectorImpl<char> &ResultPath,
unsigned Mode = all_read | all_write);
/// Simpler version for clients that don't want an open file. An empty
/// file will still be created.
std::error_code createUniqueFile(const Twine &Model,
SmallVectorImpl<char> &ResultPath,
unsigned Mode = all_read | all_write);
/// Represents a temporary file.
///
/// The temporary file must be eventually discarded or given a final name and
/// kept.
///
/// The destructor doesn't implicitly discard because there is no way to
/// properly handle errors in a destructor.
class TempFile {
bool Done = false;
TempFile(StringRef Name, int FD);
public:
/// This creates a temporary file with createUniqueFile and schedules it for
/// deletion with sys::RemoveFileOnSignal.
static Expected<TempFile> create(const Twine &Model,
unsigned Mode = all_read | all_write);
TempFile(TempFile &&Other);
TempFile &operator=(TempFile &&Other);
// Name of the temporary file.
std::string TmpName;
// The open file descriptor.
int FD = -1;
// Keep this with the given name.
Error keep(const Twine &Name);
// Keep this with the temporary name.
Error keep();
// Delete the file.
Error discard();
// This checks that keep or delete was called.
~TempFile();
};
/// Create a file in the system temporary directory.
///
/// The filename is of the form prefix-random_chars.suffix. Since the directory
/// is not know to the caller, Prefix and Suffix cannot have path separators.
/// The files are created with mode 0600.
///
/// This should be used for things like a temporary .s that is removed after
/// running the assembler.
std::error_code createTemporaryFile(const Twine &Prefix, StringRef Suffix,
int &ResultFD,
SmallVectorImpl<char> &ResultPath);
/// Simpler version for clients that don't want an open file. An empty
/// file will still be created.
std::error_code createTemporaryFile(const Twine &Prefix, StringRef Suffix,
SmallVectorImpl<char> &ResultPath);
std::error_code createUniqueDirectory(const Twine &Prefix,
SmallVectorImpl<char> &ResultPath);
/// Get a unique name, not currently exisiting in the filesystem. Subject
/// to race conditions, prefer to use createUniqueFile instead.
///
/// Similar to createUniqueFile, but instead of creating a file only
/// checks if it exists. This function is subject to race conditions, if you
/// want to use the returned name to actually create a file, use
/// createUniqueFile instead.
std::error_code getPotentiallyUniqueFileName(const Twine &Model,
SmallVectorImpl<char> &ResultPath);
/// Get a unique temporary file name, not currently exisiting in the
/// filesystem. Subject to race conditions, prefer to use createTemporaryFile
/// instead.
///
/// Similar to createTemporaryFile, but instead of creating a file only
/// checks if it exists. This function is subject to race conditions, if you
/// want to use the returned name to actually create a file, use
/// createTemporaryFile instead.
std::error_code
getPotentiallyUniqueTempFileName(const Twine &Prefix, StringRef Suffix,
SmallVectorImpl<char> &ResultPath);
inline OpenFlags operator|(OpenFlags A, OpenFlags B) {
return OpenFlags(unsigned(A) | unsigned(B));
}
inline OpenFlags &operator|=(OpenFlags &A, OpenFlags B) {
A = A | B;
return A;
}
inline FileAccess operator|(FileAccess A, FileAccess B) {
return FileAccess(unsigned(A) | unsigned(B));
}
inline FileAccess &operator|=(FileAccess &A, FileAccess B) {
A = A | B;
return A;
}
/// @brief Opens a file with the specified creation disposition, access mode,
/// and flags and returns a file descriptor.
///
/// The caller is responsible for closing the file descriptor once they are
/// finished with it.
///
/// @param Name The path of the file to open, relative or absolute.
/// @param ResultFD If the file could be opened successfully, its descriptor
/// is stored in this location. Otherwise, this is set to -1.
/// @param Disp Value specifying the existing-file behavior.
/// @param Access Value specifying whether to open the file in read, write, or
/// read-write mode.
/// @param Flags Additional flags.
/// @param Mode The access permissions of the file, represented in octal.
/// @returns errc::success if \a Name has been opened, otherwise a
/// platform-specific error_code.
std::error_code openFile(const Twine &Name, int &ResultFD,
CreationDisposition Disp, FileAccess Access,
OpenFlags Flags, unsigned Mode = 0666);
/// @brief Opens a file with the specified creation disposition, access mode,
/// and flags and returns a platform-specific file object.
///
/// The caller is responsible for closing the file object once they are
/// finished with it.
///
/// @param Name The path of the file to open, relative or absolute.
/// @param Disp Value specifying the existing-file behavior.
/// @param Access Value specifying whether to open the file in read, write, or
/// read-write mode.
/// @param Flags Additional flags.
/// @param Mode The access permissions of the file, represented in octal.
/// @returns errc::success if \a Name has been opened, otherwise a
/// platform-specific error_code.
Expected<file_t> openNativeFile(const Twine &Name, CreationDisposition Disp,
FileAccess Access, OpenFlags Flags,
unsigned Mode = 0666);
/// Converts from a Posix file descriptor number to a native file handle.
/// On Windows, this retreives the underlying handle. On non-Windows, this is a
/// no-op.
file_t convertFDToNativeFile(int FD);
#ifndef _WIN32
inline file_t convertFDToNativeFile(int FD) { return FD; }
#endif
/// Return an open handle to standard in. On Unix, this is typically FD 0.
/// Returns kInvalidFile when the stream is closed.
file_t getStdinHandle();
/// Return an open handle to standard out. On Unix, this is typically FD 1.
/// Returns kInvalidFile when the stream is closed.
file_t getStdoutHandle();
/// Return an open handle to standard error. On Unix, this is typically FD 2.
/// Returns kInvalidFile when the stream is closed.
file_t getStderrHandle();
/// Reads \p Buf.size() bytes from \p FileHandle into \p Buf. Returns the number
/// of bytes actually read. On Unix, this is equivalent to `return ::read(FD,
/// Buf.data(), Buf.size())`, with error reporting. Returns 0 when reaching EOF.
///
/// @param FileHandle File to read from.
/// @param Buf Buffer to read into.
/// @returns The number of bytes read, or error.
Expected<size_t> readNativeFile(file_t FileHandle, MutableArrayRef<char> Buf);
/// Reads \p Buf.size() bytes from \p FileHandle at offset \p Offset into \p
/// Buf. If 'pread' is available, this will use that, otherwise it will use
/// 'lseek'. Returns the number of bytes actually read. Returns 0 when reaching
/// EOF.
///
/// @param FileHandle File to read from.
/// @param Buf Buffer to read into.
/// @param Offset Offset into the file at which the read should occur.
/// @returns The number of bytes read, or error.
Expected<size_t> readNativeFileSlice(file_t FileHandle,
MutableArrayRef<char> Buf,
uint64_t Offset);
/// @brief Opens the file with the given name in a write-only or read-write
/// mode, returning its open file descriptor. If the file does not exist, it
/// is created.
///
/// The caller is responsible for closing the file descriptor once they are
/// finished with it.
///
/// @param Name The path of the file to open, relative or absolute.
/// @param ResultFD If the file could be opened successfully, its descriptor
/// is stored in this location. Otherwise, this is set to -1.
/// @param Flags Additional flags used to determine whether the file should be
/// opened in, for example, read-write or in write-only mode.
/// @param Mode The access permissions of the file, represented in octal.
/// @returns errc::success if \a Name has been opened, otherwise a
/// platform-specific error_code.
inline std::error_code
openFileForWrite(const Twine &Name, int &ResultFD,
CreationDisposition Disp = CD_CreateAlways,
OpenFlags Flags = OF_None, unsigned Mode = 0666) {
return openFile(Name, ResultFD, Disp, FA_Write, Flags, Mode);
}
/// @brief Opens the file with the given name in a write-only or read-write
/// mode, returning its open file descriptor. If the file does not exist, it
/// is created.
///
/// The caller is responsible for closing the freeing the file once they are
/// finished with it.
///
/// @param Name The path of the file to open, relative or absolute.
/// @param Flags Additional flags used to determine whether the file should be
/// opened in, for example, read-write or in write-only mode.
/// @param Mode The access permissions of the file, represented in octal.
/// @returns a platform-specific file descriptor if \a Name has been opened,
/// otherwise an error object.
inline Expected<file_t> openNativeFileForWrite(const Twine &Name,
CreationDisposition Disp,
OpenFlags Flags,
unsigned Mode = 0666) {
return openNativeFile(Name, Disp, FA_Write, Flags, Mode);
}
/// @brief Opens the file with the given name in a write-only or read-write
/// mode, returning its open file descriptor. If the file does not exist, it
/// is created.
///
/// The caller is responsible for closing the file descriptor once they are
/// finished with it.
///
/// @param Name The path of the file to open, relative or absolute.
/// @param ResultFD If the file could be opened successfully, its descriptor
/// is stored in this location. Otherwise, this is set to -1.
/// @param Flags Additional flags used to determine whether the file should be
/// opened in, for example, read-write or in write-only mode.
/// @param Mode The access permissions of the file, represented in octal.
/// @returns errc::success if \a Name has been opened, otherwise a
/// platform-specific error_code.
inline std::error_code openFileForReadWrite(const Twine &Name, int &ResultFD,
CreationDisposition Disp,
OpenFlags Flags,
unsigned Mode = 0666) {
return openFile(Name, ResultFD, Disp, FA_Write | FA_Read, Flags, Mode);
}
/// @brief Opens the file with the given name in a write-only or read-write
/// mode, returning its open file descriptor. If the file does not exist, it
/// is created.
///
/// The caller is responsible for closing the freeing the file once they are
/// finished with it.
///
/// @param Name The path of the file to open, relative or absolute.
/// @param Flags Additional flags used to determine whether the file should be
/// opened in, for example, read-write or in write-only mode.
/// @param Mode The access permissions of the file, represented in octal.
/// @returns a platform-specific file descriptor if \a Name has been opened,
/// otherwise an error object.
inline Expected<file_t> openNativeFileForReadWrite(const Twine &Name,
CreationDisposition Disp,
OpenFlags Flags,
unsigned Mode = 0666) {
return openNativeFile(Name, Disp, FA_Write | FA_Read, Flags, Mode);
}
/// @brief Opens the file with the given name in a read-only mode, returning
/// its open file descriptor.
///
/// The caller is responsible for closing the file descriptor once they are
/// finished with it.
///
/// @param Name The path of the file to open, relative or absolute.
/// @param ResultFD If the file could be opened successfully, its descriptor
/// is stored in this location. Otherwise, this is set to -1.
/// @param RealPath If nonnull, extra work is done to determine the real path
/// of the opened file, and that path is stored in this
/// location.
/// @returns errc::success if \a Name has been opened, otherwise a
/// platform-specific error_code.
std::error_code openFileForRead(const Twine &Name, int &ResultFD,
OpenFlags Flags = OF_None,
SmallVectorImpl<char> *RealPath = nullptr);
/// @brief Opens the file with the given name in a read-only mode, returning
/// its open file descriptor.
///
/// The caller is responsible for closing the freeing the file once they are
/// finished with it.
///
/// @param Name The path of the file to open, relative or absolute.
/// @param RealPath If nonnull, extra work is done to determine the real path
/// of the opened file, and that path is stored in this
/// location.
/// @returns a platform-specific file descriptor if \a Name has been opened,
/// otherwise an error object.
Expected<file_t>
openNativeFileForRead(const Twine &Name, OpenFlags Flags = OF_None,
SmallVectorImpl<char> *RealPath = nullptr);
/// Try to locks the file during the specified time.
///
/// This function implements advisory locking on entire file. If it returns
/// <em>errc::success</em>, the file is locked by the calling process. Until the
/// process unlocks the file by calling \a unlockFile, all attempts to lock the
/// same file will fail/block. The process that locked the file may assume that
/// none of other processes read or write this file, provided that all processes
/// lock the file prior to accessing its content.
///
/// @param FD The descriptor representing the file to lock.
/// @param Timeout Time in milliseconds that the process should wait before
/// reporting lock failure. Zero value means try to get lock only
/// once.
/// @returns errc::success if lock is successfully obtained,
/// errc::no_lock_available if the file cannot be locked, or platform-specific
/// error_code otherwise.
///
/// @note Care should be taken when using this function in a multithreaded
/// context, as it may not prevent other threads in the same process from
/// obtaining a lock on the same file, even if they are using a different file
/// descriptor.
std::error_code
tryLockFile(int FD,
std::chrono::milliseconds Timeout = std::chrono::milliseconds(0));
/// Lock the file.
///
/// This function acts as @ref tryLockFile but it waits infinitely.
std::error_code lockFile(int FD);
/// Unlock the file.
///
/// @param FD The descriptor representing the file to unlock.
/// @returns errc::success if lock is successfully released or platform-specific
/// error_code otherwise.
std::error_code unlockFile(int FD);
/// @brief Close the file object. This should be used instead of ::close for
/// portability. On error, the caller should assume the file is closed, as is
/// the case for Process::SafelyCloseFileDescriptor
///
/// @param F On input, this is the file to close. On output, the file is
/// set to kInvalidFile.
///
/// @returns An error code if closing the file failed. Typically, an error here
/// means that the filesystem may have failed to perform some buffered writes.
std::error_code closeFile(file_t &F);
/// RAII class that facilitates file locking.
class FileLocker {
int FD; ///< Locked file handle.
FileLocker(int FD) : FD(FD) {}
friend class llvm::raw_fd_ostream;
public:
FileLocker(const FileLocker &L) = delete;
FileLocker(FileLocker &&L) : FD(L.FD) { L.FD = -1; }
~FileLocker() {
if (FD != -1)
unlockFile(FD);
}
FileLocker &operator=(FileLocker &&L) {
FD = L.FD;
L.FD = -1;
return *this;
}
FileLocker &operator=(const FileLocker &L) = delete;
std::error_code unlock() {
if (FD != -1) {
std::error_code Result = unlockFile(FD);
FD = -1;
return Result;
}
return std::error_code();
}
};
std::error_code getUniqueID(const Twine Path, UniqueID &Result);
/// Get disk space usage information.
///
/// Note: Users must be careful about "Time Of Check, Time Of Use" kind of bug.
/// Note: Windows reports results according to the quota allocated to the user.
///
/// @param Path Input path.
/// @returns a space_info structure filled with the capacity, free, and
/// available space on the device \a Path is on. A platform specific error_code
/// is returned on error.
ErrorOr<space_info> disk_space(const Twine &Path);
/// This class represents a memory mapped file. It is based on
/// boost::iostreams::mapped_file.
class mapped_file_region {
public:
enum mapmode {
readonly, ///< May only access map via const_data as read only.
readwrite, ///< May access map via data and modify it. Written to path.
priv ///< May modify via data, but changes are lost on destruction.
};
private:
/// Platform-specific mapping state.
size_t Size;
void *Mapping;
#ifdef _WIN32
sys::fs::file_t FileHandle;
#endif
mapmode Mode;
std::error_code init(sys::fs::file_t FD, uint64_t Offset, mapmode Mode);
public:
mapped_file_region() = delete;
mapped_file_region(mapped_file_region&) = delete;
mapped_file_region &operator =(mapped_file_region&) = delete;
/// \param fd An open file descriptor to map. Does not take ownership of fd.
mapped_file_region(sys::fs::file_t fd, mapmode mode, size_t length, uint64_t offset,
std::error_code &ec);
~mapped_file_region();
size_t size() const;
char *data() const;
/// Get a const view of the data. Modifying this memory has undefined
/// behavior.
const char *const_data() const;
/// \returns The minimum alignment offset must be.
static int alignment();
};
/// Return the path to the main executable, given the value of argv[0] from
/// program startup and the address of main itself. In extremis, this function
/// may fail and return an empty path.
std::string getMainExecutable(const char *argv0, void *MainExecAddr);
/// @}
/// @name Iterators
/// @{
/// directory_entry - A single entry in a directory.
class directory_entry {
// FIXME: different platforms make different information available "for free"
// when traversing a directory. The design of this class wraps most of the
// information in basic_file_status, so on platforms where we can't populate
// that whole structure, callers end up paying for a stat().
// std::filesystem::directory_entry may be a better model.
std::string Path;
file_type Type = file_type::type_unknown; // Most platforms can provide this.
bool FollowSymlinks = true; // Affects the behavior of status().
basic_file_status Status; // If available.
public:
explicit directory_entry(const Twine &Path, bool FollowSymlinks = true,
file_type Type = file_type::type_unknown,
basic_file_status Status = basic_file_status())
: Path(Path.str()), Type(Type), FollowSymlinks(FollowSymlinks),
Status(Status) {}
directory_entry() = default;
void replace_filename(const Twine &Filename, file_type Type,
basic_file_status Status = basic_file_status());
const std::string &path() const { return Path; }
// Get basic information about entry file (a subset of fs::status()).
// On most platforms this is a stat() call.
// On windows the information was already retrieved from the directory.
ErrorOr<basic_file_status> status() const;
// Get the type of this file.
// On most platforms (Linux/Mac/Windows/BSD), this was already retrieved.
// On some platforms (e.g. Solaris) this is a stat() call.
file_type type() const {
if (Type != file_type::type_unknown)
return Type;
auto S = status();
return S ? S->type() : file_type::type_unknown;
}
bool operator==(const directory_entry& RHS) const { return Path == RHS.Path; }
bool operator!=(const directory_entry& RHS) const { return !(*this == RHS); }
bool operator< (const directory_entry& RHS) const;
bool operator<=(const directory_entry& RHS) const;
bool operator> (const directory_entry& RHS) const;
bool operator>=(const directory_entry& RHS) const;
};
namespace detail {
struct DirIterState;
std::error_code directory_iterator_construct(DirIterState &, StringRef, bool);
std::error_code directory_iterator_increment(DirIterState &);
std::error_code directory_iterator_destruct(DirIterState &);
/// Keeps state for the directory_iterator.
struct DirIterState {
~DirIterState() {
directory_iterator_destruct(*this);
}
intptr_t IterationHandle = 0;
directory_entry CurrentEntry;
};
} // end namespace detail
/// directory_iterator - Iterates through the entries in path. There is no
/// operator++ because we need an error_code. If it's really needed we can make
/// it call report_fatal_error on error.
class directory_iterator {
std::shared_ptr<detail::DirIterState> State;
bool FollowSymlinks = true;
public:
explicit directory_iterator(const Twine &path, std::error_code &ec,
bool follow_symlinks = true)
: FollowSymlinks(follow_symlinks) {
State = std::make_shared<detail::DirIterState>();
SmallString<128> path_storage;
ec = detail::directory_iterator_construct(
*State, path.toStringRef(path_storage), FollowSymlinks);
}
explicit directory_iterator(const directory_entry &de, std::error_code &ec,
bool follow_symlinks = true)
: FollowSymlinks(follow_symlinks) {
State = std::make_shared<detail::DirIterState>();
ec = detail::directory_iterator_construct(
*State, de.path(), FollowSymlinks);
}
/// Construct end iterator.
directory_iterator() = default;
// No operator++ because we need error_code.
directory_iterator &increment(std::error_code &ec) {
ec = directory_iterator_increment(*State);
return *this;
}
const directory_entry &operator*() const { return State->CurrentEntry; }
const directory_entry *operator->() const { return &State->CurrentEntry; }
bool operator==(const directory_iterator &RHS) const {
if (State == RHS.State)
return true;
if (!RHS.State)
return State->CurrentEntry == directory_entry();
if (!State)
return RHS.State->CurrentEntry == directory_entry();
return State->CurrentEntry == RHS.State->CurrentEntry;
}
bool operator!=(const directory_iterator &RHS) const {
return !(*this == RHS);
}
};
namespace detail {
/// Keeps state for the recursive_directory_iterator.
struct RecDirIterState {
std::stack<directory_iterator, std::vector<directory_iterator>> Stack;
uint16_t Level = 0;
bool HasNoPushRequest = false;
};
} // end namespace detail
/// recursive_directory_iterator - Same as directory_iterator except for it
/// recurses down into child directories.
class recursive_directory_iterator {
std::shared_ptr<detail::RecDirIterState> State;
bool Follow;
public:
recursive_directory_iterator() = default;
explicit recursive_directory_iterator(const Twine &path, std::error_code &ec,
bool follow_symlinks = true)
: State(std::make_shared<detail::RecDirIterState>()),
Follow(follow_symlinks) {
State->Stack.push(directory_iterator(path, ec, Follow));
if (State->Stack.top() == directory_iterator())
State.reset();
}
// No operator++ because we need error_code.
recursive_directory_iterator &increment(std::error_code &ec) {
const directory_iterator end_itr = {};
if (State->HasNoPushRequest)
State->HasNoPushRequest = false;
else {
file_type type = State->Stack.top()->type();
if (type == file_type::symlink_file && Follow) {
// Resolve the symlink: is it a directory to recurse into?
ErrorOr<basic_file_status> status = State->Stack.top()->status();
if (status)
type = status->type();
// Otherwise broken symlink, and we'll continue.
}
if (type == file_type::directory_file) {
State->Stack.push(directory_iterator(*State->Stack.top(), ec, Follow));
if (State->Stack.top() != end_itr) {
++State->Level;
return *this;
}
State->Stack.pop();
}
}
while (!State->Stack.empty()
&& State->Stack.top().increment(ec) == end_itr) {
State->Stack.pop();
--State->Level;
}
// Check if we are done. If so, create an end iterator.
if (State->Stack.empty())
State.reset();
return *this;
}
const directory_entry &operator*() const { return *State->Stack.top(); }
const directory_entry *operator->() const { return &*State->Stack.top(); }
// observers
/// Gets the current level. Starting path is at level 0.
int level() const { return State->Level; }
/// Returns true if no_push has been called for this directory_entry.
bool no_push_request() const { return State->HasNoPushRequest; }
// modifiers
/// Goes up one level if Level > 0.
void pop() {
assert(State && "Cannot pop an end iterator!");
assert(State->Level > 0 && "Cannot pop an iterator with level < 1");
const directory_iterator end_itr = {};
std::error_code ec;
do {
if (ec)
report_fatal_error("Error incrementing directory iterator.");
State->Stack.pop();
--State->Level;
} while (!State->Stack.empty()
&& State->Stack.top().increment(ec) == end_itr);
// Check if we are done. If so, create an end iterator.
if (State->Stack.empty())
State.reset();
}
/// Does not go down into the current directory_entry.
void no_push() { State->HasNoPushRequest = true; }
bool operator==(const recursive_directory_iterator &RHS) const {
return State == RHS.State;
}
bool operator!=(const recursive_directory_iterator &RHS) const {
return !(*this == RHS);
}
};
/// @}
} // end namespace fs
} // end namespace sys
} // end namespace llvm
#endif // LLVM_SUPPORT_FILESYSTEM_H
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