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// Copyright 2017 The Bazel Authors. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#ifndef BAZEL_SRC_MAIN_NATIVE_WINDOWS_FILE_H_
#define BAZEL_SRC_MAIN_NATIVE_WINDOWS_FILE_H_
#include <windows.h>
#include <memory>
#include <string>
namespace bazel {
namespace windows {
using std::unique_ptr;
using std::wstring;
template <typename char_type>
bool HasUncPrefix(const char_type* path) {
// Return true iff `path` starts with "\\?\", "\\.\", or "\??\".
return path[0] == '\\' &&
((path[1] == '\\' && (path[2] == '?' || path[2] == '.')) ||
(path[1] == '?' && path[2] == '?')) &&
path[3] == '\\';
}
// Keep in sync with j.c.g.devtools.build.lib.windows.WindowsFileOperations
enum {
IS_JUNCTION_YES = 0,
IS_JUNCTION_NO = 1,
IS_JUNCTION_ERROR = 2,
};
// Keep in sync with j.c.g.devtools.build.lib.windows.WindowsFileOperations
struct DeletePathResult {
enum {
kSuccess = 0,
kError = 1,
kDoesNotExist = 2,
kDirectoryNotEmpty = 3,
kAccessDenied = 4,
};
};
struct CreateJunctionResult {
enum {
kSuccess = 0,
kError = 1,
kTargetNameTooLong = 2,
kAlreadyExistsWithDifferentTarget = 3,
kAlreadyExistsButNotJunction = 4,
kAccessDenied = 5,
kDisappeared = 6,
};
};
// Determines whether `path` is a junction (or directory symlink).
//
// `path` should be an absolute, normalized, Windows-style path, with "\\?\"
// prefix if it's longer than MAX_PATH.
//
// To read about differences between junctions and directory symlinks,
// see http://superuser.com/a/343079. In Bazel we only ever create junctions.
//
// Returns:
// - IS_JUNCTION_YES, if `path` exists and is either a directory junction or a
// directory symlink
// - IS_JUNCTION_NO, if `path` exists but is neither a directory junction nor a
// directory symlink; also when `path` is a symlink to a directory but it was
// created using "mklink" instead of "mklink /d", as such symlinks don't
// behave the same way as directories (e.g. they can't be listed)
// - IS_JUNCTION_ERROR, if `path` doesn't exist or some error occurred
int IsJunctionOrDirectorySymlink(const WCHAR* path);
// Computes the long version of `path` if it has any 8dot3 style components.
// Returns the empty string upon success, or a human-readable error message upon
// failure.
// `path` must be an absolute, normalized, Windows style path, with a "\\?\"
// prefix if it's longer than MAX_PATH. The result will have a "\\?\" prefix if
// and only if `path` had one as well. (It's the caller's responsibility to keep
// or remove this prefix.)
// TODO(laszlocsomor): update GetLongPath so it succeeds even if the path does
// not (fully) exist.
wstring GetLongPath(const WCHAR* path, unique_ptr<WCHAR[]>* result);
// Opens a directory using CreateFileW.
// `path` must be a valid Windows path, with "\\?\" prefix if it's long.
// If `read_write` is true then the directory is opened for reading and writing,
// otherwise only for reading.
HANDLE OpenDirectory(const WCHAR* path, bool read_write);
// Creates a junction at `name`, pointing to `target`.
// Returns CreateJunctionResult::kSuccess if it could create the junction, or if
// the junction already exists with the same target.
// If the junction's name already exists as an empty directory, this function
// will turn it into a junction and return kSuccess.
// Otherwise returns one of the other CreateJunctionResult::k* constants for
// known error cases, or CreateJunctionResult::kError for unknown error cases.
// When the function returns CreateJunctionResult::kError, and `error` is
// non-null, the function writes an error message into `error`. If the return
// value is anything other than CreateJunctionResult::kError, then this function
// ignores the `error` argument.
//
// Neither `junction_name` nor `junction_target` needs to have a "\\?\" prefix,
// not even if they are longer than MAX_PATH, though it's okay if they do. This
// function will add the right prefixes as necessary.
int CreateJunction(const wstring& junction_name, const wstring& junction_target,
wstring* error);
// Deletes the file, junction, or empty directory at `path`.
// Returns DELETE_PATH_SUCCESS if it successfully deleted the path, otherwise
// returns one of the other DELETE_PATH_* constants (e.g. when the directory is
// not empty or the file is in use by another process).
// Returns DELETE_PATH_ERROR for unexpected errors. If `error` is not null, the
// function writes an error message into it.
int DeletePath(const wstring& path, wstring* error);
} // namespace windows
} // namespace bazel
#endif // BAZEL_SRC_MAIN_NATIVE_WINDOWS_FILE_H_
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