//===- llvm/Support/Path.h - Path Operating System 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::path namespace. It is designed after

// TR2/boost filesystem (v3), but modified to remove exception handling and the

// path class.

//

//===----------------------------------------------------------------------===//

#ifndef LLVM_SUPPORT_PATH_H

#define LLVM_SUPPORT_PATH_H

#include "llvm/ADT/Twine.h"

#include "llvm/ADT/iterator.h"

#include "llvm/Support/DataTypes.h"

#include <iterator>

#include <system_error>

namespace llvm {

namespace sys {

namespace path {

enum class Style { windows, posix, native };

/// @name Lexical Component Iterator

/// @{

/// Path iterator.

///

/// This is an input iterator that iterates over the individual components in

/// \a path. The traversal order is as follows:

/// * The root-name element, if present.

/// * The root-directory element, if present.

/// * Each successive filename element, if present.

/// * Dot, if one or more trailing non-root slash characters are present.

/// Traversing backwards is possible with \a reverse_iterator

///

/// Iteration examples. Each component is separated by ',':

/// @code

///   /          => /

///   /foo       => /,foo

///   foo/       => foo,.

///   /foo/bar   => /,foo,bar

///   ../        => ..,.

///   C:\foo\bar => C:,\,foo,bar

/// @endcode

class const_iterator

    : public iterator_facade_base<const_iterator, std::input_iterator_tag,

                                  const StringRef> {

  StringRef Path;          ///< The entire path.

  StringRef Component;     ///< The current component. Not necessarily in Path.

  size_t    Position = 0;  ///< The iterators current position within Path.

  Style S = Style::native; ///< The path style to use.

  // An end iterator has Position = Path.size() + 1.

  friend const_iterator begin(StringRef path, Style style);

  friend const_iterator end(StringRef path);

public:

  reference operator*() const { return Component; }

  const_iterator &operator++();    // preincrement

  bool operator==(const const_iterator &RHS) const;

  /// Difference in bytes between this and RHS.

  ptrdiff_t operator-(const const_iterator &RHS) const;

};

/// Reverse path iterator.

///

/// This is an input iterator that iterates over the individual components in

/// \a path in reverse order. The traversal order is exactly reversed from that

/// of \a const_iterator

class reverse_iterator

    : public iterator_facade_base<reverse_iterator, std::input_iterator_tag,

                                  const StringRef> {

  StringRef Path;          ///< The entire path.

  StringRef Component;     ///< The current component. Not necessarily in Path.

  size_t    Position = 0;  ///< The iterators current position within Path.

  Style S = Style::native; ///< The path style to use.

  friend reverse_iterator rbegin(StringRef path, Style style);

  friend reverse_iterator rend(StringRef path);

public:

  reference operator*() const { return Component; }

  reverse_iterator &operator++();    // preincrement

  bool operator==(const reverse_iterator &RHS) const;

  /// Difference in bytes between this and RHS.

  ptrdiff_t operator-(const reverse_iterator &RHS) const;

};

/// Get begin iterator over \a path.

/// @param path Input path.

/// @returns Iterator initialized with the first component of \a path.

const_iterator begin(StringRef path, Style style = Style::native);

/// Get end iterator over \a path.

/// @param path Input path.

/// @returns Iterator initialized to the end of \a path.

const_iterator end(StringRef path);

/// Get reverse begin iterator over \a path.

/// @param path Input path.

/// @returns Iterator initialized with the first reverse component of \a path.

reverse_iterator rbegin(StringRef path, Style style = Style::native);

/// Get reverse end iterator over \a path.

/// @param path Input path.

/// @returns Iterator initialized to the reverse end of \a path.

reverse_iterator rend(StringRef path);

/// @}

/// @name Lexical Modifiers

/// @{

/// Remove the last component from \a path unless it is the root dir.

///

/// Similar to the POSIX "dirname" utility.

///

/// @code

///   directory/filename.cpp => directory/

///   directory/             => directory

///   filename.cpp           => <empty>

///   /                      => /

/// @endcode

///

/// @param path A path that is modified to not have a file component.

void remove_filename(SmallVectorImpl<char> &path, Style style = Style::native);

/// Replace the file extension of \a path with \a extension.

///

/// @code

///   ./filename.cpp => ./filename.extension

///   ./filename     => ./filename.extension

///   ./             => ./.extension

/// @endcode

///

/// @param path A path that has its extension replaced with \a extension.

/// @param extension The extension to be added. It may be empty. It may also

///                  optionally start with a '.', if it does not, one will be

///                  prepended.

void replace_extension(SmallVectorImpl<char> &path, const Twine &extension,

                       Style style = Style::native);

/// Replace matching path prefix with another path.

///

/// @code

///   /foo, /old, /new => /foo

///   /old, /old, /new => /new

///   /old, /old/, /new => /old

///   /old/foo, /old, /new => /new/foo

///   /old/foo, /old/, /new => /new/foo

///   /old/foo, /old/, /new/ => /new/foo

///   /oldfoo, /old, /new => /oldfoo

///   /foo, <empty>, /new => /new/foo

///   /foo, <empty>, new => new/foo

///   /old/foo, /old, <empty> => /foo

/// @endcode

///

/// @param Path If \a Path starts with \a OldPrefix modify to instead

///        start with \a NewPrefix.

/// @param OldPrefix The path prefix to strip from \a Path.

/// @param NewPrefix The path prefix to replace \a NewPrefix with.

/// @param style The style used to match the prefix. Exact match using

/// Posix style, case/separator insensitive match for Windows style.

/// @result true if \a Path begins with OldPrefix

bool replace_path_prefix(SmallVectorImpl<char> &Path, StringRef OldPrefix,

                         StringRef NewPrefix,

                         Style style = Style::native);

/// Append to path.

///

/// @code

///   /foo  + bar/f => /foo/bar/f

///   /foo/ + bar/f => /foo/bar/f

///   foo   + bar/f => foo/bar/f

/// @endcode

///

/// @param path Set to \a path + \a component.

/// @param a The component to be appended to \a path.

void append(SmallVectorImpl<char> &path, const Twine &a,

                                         const Twine &b = "",

                                         const Twine &c = "",

                                         const Twine &d = "");

void append(SmallVectorImpl<char> &path, Style style, const Twine &a,

            const Twine &b = "", const Twine &c = "", const Twine &d = "");

/// Append to path.

///

/// @code

///   /foo  + [bar,f] => /foo/bar/f

///   /foo/ + [bar,f] => /foo/bar/f

///   foo   + [bar,f] => foo/bar/f

/// @endcode

///

/// @param path Set to \a path + [\a begin, \a end).

/// @param begin Start of components to append.

/// @param end One past the end of components to append.

void append(SmallVectorImpl<char> &path, const_iterator begin,

            const_iterator end, Style style = Style::native);

/// @}

/// @name Transforms (or some other better name)

/// @{

/// Convert path to the native form. This is used to give paths to users and

/// operating system calls in the platform's normal way. For example, on Windows

/// all '/' are converted to '\'.

///

/// @param path A path that is transformed to native format.

/// @param result Holds the result of the transformation.

void native(const Twine &path, SmallVectorImpl<char> &result,

            Style style = Style::native);

/// Convert path to the native form in place. This is used to give paths to

/// users and operating system calls in the platform's normal way. For example,

/// on Windows all '/' are converted to '\'.

///

/// @param path A path that is transformed to native format.

void native(SmallVectorImpl<char> &path, Style style = Style::native);

/// Replaces backslashes with slashes if Windows.

///

/// @param path processed path

/// @result The result of replacing backslashes with forward slashes if Windows.

/// On Unix, this function is a no-op because backslashes are valid path

/// chracters.

std::string convert_to_slash(StringRef path, Style style = Style::native);

/// @}

/// @name Lexical Observers

/// @{

/// Get root name.

///

/// @code

///   //net/hello => //net

///   c:/hello    => c: (on Windows, on other platforms nothing)

///   /hello      => <empty>

/// @endcode

///

/// @param path Input path.

/// @result The root name of \a path if it has one, otherwise "".

StringRef root_name(StringRef path, Style style = Style::native);

/// Get root directory.

///

/// @code

///   /goo/hello => /

///   c:/hello   => /

///   d/file.txt => <empty>

/// @endcode

///

/// @param path Input path.

/// @result The root directory of \a path if it has one, otherwise

///               "".

StringRef root_directory(StringRef path, Style style = Style::native);

/// Get root path.

///

/// Equivalent to root_name + root_directory.

///

/// @param path Input path.

/// @result The root path of \a path if it has one, otherwise "".

StringRef root_path(StringRef path, Style style = Style::native);

/// Get relative path.

///

/// @code

///   C:\hello\world => hello\world

///   foo/bar        => foo/bar

///   /foo/bar       => foo/bar

/// @endcode

///

/// @param path Input path.

/// @result The path starting after root_path if one exists, otherwise "".

StringRef relative_path(StringRef path, Style style = Style::native);

/// Get parent path.

///

/// @code

///   /          => <empty>

///   /foo       => /

///   foo/../bar => foo/..

/// @endcode

///

/// @param path Input path.

/// @result The parent path of \a path if one exists, otherwise "".

StringRef parent_path(StringRef path, Style style = Style::native);

/// Get filename.

///

/// @code

///   /foo.txt    => foo.txt

///   .          => .

///   ..         => ..

///   /          => /

/// @endcode

///

/// @param path Input path.

/// @result The filename part of \a path. This is defined as the last component

///         of \a path. Similar to the POSIX "basename" utility.

StringRef filename(StringRef path, Style style = Style::native);

/// Get stem.

///

/// If filename contains a dot but not solely one or two dots, result is the

/// substring of filename ending at (but not including) the last dot. Otherwise

/// it is filename.

///

/// @code

///   /foo/bar.txt => bar

///   /foo/bar     => bar

///   /foo/.txt    => <empty>

///   /foo/.       => .

///   /foo/..      => ..

/// @endcode

///

/// @param path Input path.

/// @result The stem of \a path.

StringRef stem(StringRef path, Style style = Style::native);

/// Get extension.

///

/// If filename contains a dot but not solely one or two dots, result is the

/// substring of filename starting at (and including) the last dot, and ending

/// at the end of \a path. Otherwise "".

///

/// @code

///   /foo/bar.txt => .txt

///   /foo/bar     => <empty>

///   /foo/.txt    => .txt

/// @endcode

///

/// @param path Input path.

/// @result The extension of \a path.

StringRef extension(StringRef path, Style style = Style::native);

/// Check whether the given char is a path separator on the host OS.

///

/// @param value a character

/// @result true if \a value is a path separator character on the host OS

bool is_separator(char value, Style style = Style::native);

/// Return the preferred separator for this platform.

///

/// @result StringRef of the preferred separator, null-terminated.

StringRef get_separator(Style style = Style::native);

/// Get the typical temporary directory for the system, e.g.,

/// "/var/tmp" or "C:/TEMP"

///

/// @param erasedOnReboot Whether to favor a path that is erased on reboot

/// rather than one that potentially persists longer. This parameter will be

/// ignored if the user or system has set the typical environment variable

/// (e.g., TEMP on Windows, TMPDIR on *nix) to specify a temporary directory.

///

/// @param result Holds the resulting path name.

void system_temp_directory(bool erasedOnReboot, SmallVectorImpl<char> &result);

/// Get the user's home directory.

///

/// @param result Holds the resulting path name.

/// @result True if a home directory is set, false otherwise.

bool home_directory(SmallVectorImpl<char> &result);

/// Get the directory where installed packages should put their

/// machine-local cache, e.g. $XDG_CACHE_HOME.

///

/// @param result Holds the resulting path name.

/// @result True if the appropriate path was determined, it need not exist.

bool cache_directory(SmallVectorImpl<char> &result);

/// Has root name?

///

/// root_name != ""

///

/// @param path Input path.

/// @result True if the path has a root name, false otherwise.

bool has_root_name(const Twine &path, Style style = Style::native);

/// Has root directory?

///

/// root_directory != ""

///

/// @param path Input path.

/// @result True if the path has a root directory, false otherwise.

bool has_root_directory(const Twine &path, Style style = Style::native);

/// Has root path?

///

/// root_path != ""

///

/// @param path Input path.

/// @result True if the path has a root path, false otherwise.

bool has_root_path(const Twine &path, Style style = Style::native);

/// Has relative path?

///

/// relative_path != ""

///

/// @param path Input path.

/// @result True if the path has a relative path, false otherwise.

bool has_relative_path(const Twine &path, Style style = Style::native);

/// Has parent path?

///

/// parent_path != ""

///

/// @param path Input path.

/// @result True if the path has a parent path, false otherwise.

bool has_parent_path(const Twine &path, Style style = Style::native);

/// Has filename?

///

/// filename != ""

///

/// @param path Input path.

/// @result True if the path has a filename, false otherwise.

bool has_filename(const Twine &path, Style style = Style::native);

/// Has stem?

///

/// stem != ""

///

/// @param path Input path.

/// @result True if the path has a stem, false otherwise.

bool has_stem(const Twine &path, Style style = Style::native);

/// Has extension?

///

/// extension != ""

///

/// @param path Input path.

/// @result True if the path has a extension, false otherwise.

bool has_extension(const Twine &path, Style style = Style::native);

/// Is path absolute?

///

/// @param path Input path.

/// @result True if the path is absolute, false if it is not.

bool is_absolute(const Twine &path, Style style = Style::native);

/// Is path relative?

///

/// @param path Input path.

/// @result True if the path is relative, false if it is not.

bool is_relative(const Twine &path, Style style = Style::native);

/// Remove redundant leading "./" pieces and consecutive separators.

///

/// @param path Input path.

/// @result The cleaned-up \a path.

StringRef remove_leading_dotslash(StringRef path, Style style = Style::native);

/// In-place remove any './' and optionally '../' components from a path.

///

/// @param path processed path

/// @param remove_dot_dot specify if '../' (except for leading "../") should be

/// removed

/// @result True if path was changed

bool remove_dots(SmallVectorImpl<char> &path, bool remove_dot_dot = false,

                 Style style = Style::native);

} // end namespace path

} // end namespace sys

} // end namespace llvm

#endif