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// Copyright 2016 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_CPP_UTIL_FILE_PLATFORM_H_
#define BAZEL_SRC_MAIN_CPP_UTIL_FILE_PLATFORM_H_
#include <time.h>
#include <cinttypes>
#include <string>
#include <vector>
namespace blaze_util {
class Path;
class IPipe;
IPipe* CreatePipe();
// Class to query/manipulate the last modification time (mtime) of files.
class IFileMtime {
public:
virtual ~IFileMtime() {}
// Checks if `path` is a file/directory in the embedded tools directory that
// was not tampered with.
// Returns true if `path` is a directory or directory symlink, or if `path` is
// a file with an mtime in the distant future.
// Returns false otherwise, or if querying the information failed.
// TODO(laszlocsomor): move this function, and with it the whole IFileMtime
// class into blaze_util_<platform>.cc, because it is Bazel-specific logic,
// not generic file-handling logic.
virtual bool IsUntampered(const Path &path) = 0;
// Sets the mtime of file under `path` to the current time.
// Returns true if the mtime was changed successfully.
virtual bool SetToNow(const Path &path) = 0;
// Sets the mtime of file under `path` to the distant future.
// "Distant future" should be on the order of some years into the future, like
// a decade.
// Returns true if the mtime was changed successfully.
virtual bool SetToDistantFuture(const Path &path) = 0;
};
// Creates a platform-specific implementation of `IFileMtime`.
IFileMtime *CreateFileMtime();
#if defined(_WIN32) || defined(__CYGWIN__)
// We cannot include <windows.h> because it #defines many symbols that conflict
// with our function names, e.g. GetUserName, SendMessage.
// Instead of typedef'ing HANDLE, let's use the actual type, void*. If that ever
// changes in the future and HANDLE would no longer be compatible with void*
// (very unlikely, given how fundamental this type is in Windows), then we'd get
// a compilation error.
typedef /* HANDLE */ void *file_handle_type;
#else // !(defined(_WIN32) || defined(__CYGWIN__))
typedef int file_handle_type;
#endif // defined(_WIN32) || defined(__CYGWIN__)
// Result of a `ReadFromHandle` operation.
//
// This is a platform-independent abstraction of `errno`. If you need to handle
// an errno value, add an entry here and update the platform-specific
// `ReadFromHandle` implementations accordingly.
struct ReadFileResult {
enum Errors {
SUCCESS = 0,
OTHER_ERROR = 1,
INTERRUPTED = 2,
AGAIN = 3,
};
};
int ReadFromHandle(file_handle_type handle, void *data, size_t size,
int *error);
// Replaces 'content' with contents of file 'filename'.
// If `max_size` is positive, the method reads at most that many bytes;
// otherwise the method reads the whole file.
// If fails to read content from the file, `error_message` can provide extra
// information about the failure.
// Returns false on error. Can be called from a signal handler.
bool ReadFile(const std::string &filename, std::string *content,
std::string *error_message, int max_size = 0);
bool ReadFile(const std::string &filename, std::string *content,
int max_size = 0);
bool ReadFile(const Path &path, std::string *content, int max_size = 0);
// Reads up to `size` bytes from the file `filename` into `data`.
// There must be enough memory allocated at `data`.
// Returns true on success, false on error.
bool ReadFile(const std::string &filename, void *data, size_t size);
bool ReadFile(const Path &filename, void *data, size_t size);
// Writes `size` bytes from `data` into file `filename` and chmods it to `perm`.
// Returns false on failure, sets errno.
bool WriteFile(const void *data, size_t size, const std::string &filename,
unsigned int perm = 0644);
bool WriteFile(const void *data, size_t size, const Path &path,
unsigned int perm = 0644);
// Result of a `WriteToStdOutErr` operation.
//
// This is a platform-independent abstraction of `errno`. If you need to handle
// an errno value, add an entry here and update the platform-specific
// `WriteToStdOutErr` implementations accordingly.
struct WriteResult {
enum Errors {
SUCCESS = 0,
OTHER_ERROR = 1, // some uncategorized error occurred
BROKEN_PIPE = 2, // EPIPE (reading end of the pipe is closed)
};
};
// Writes `size` bytes from `data` into stdout/stderr.
// Writes to stdout if `to_stdout` is true, writes to stderr otherwise.
// Returns one of `WriteResult::Errors`.
//
// This is a platform-independent abstraction of `fwrite` with `errno` checking
// and awareness of pipes (i.e. in case stderr/stdout is connected to a pipe).
int WriteToStdOutErr(const void *data, size_t size, bool to_stdout);
enum RenameDirectoryResult {
kRenameDirectorySuccess = 0,
kRenameDirectoryFailureNotEmpty = 1,
kRenameDirectoryFailureOtherError = 2,
};
// Renames the directory at `old_name` to `new_name`.
// Returns one of the RenameDirectoryResult enum values.
int RenameDirectory(const std::string &old_name, const std::string &new_name);
// Reads which directory a symlink points to. Puts the target of the symlink
// in ``result`` and returns if the operation was successful. Will not work on
// symlinks that don't point to directories on Windows.
bool ReadDirectorySymlink(const blaze_util::Path &symlink, std::string *result);
// Unlinks the file given by 'file_path'.
// Returns true on success. In case of failure sets errno.
bool UnlinkPath(const std::string &file_path);
bool UnlinkPath(const Path &file_path);
// Returns true if this path exists, following symlinks.
bool PathExists(const std::string& path);
bool PathExists(const Path &path);
// Returns the real, absolute path corresponding to `path`.
// The method resolves all symlink components of `path`.
// Returns the empty string upon error.
//
// This is a wrapper around realpath(3).
std::string MakeCanonical(const char *path);
// Returns true if `path` exists, is a file or symlink to one, and is readable.
// Follows symlinks.
bool CanReadFile(const std::string &path);
bool CanReadFile(const Path &path);
// Returns true if `path` exists, is a file or symlink to one, and is writable.
// Follows symlinks.
bool CanExecuteFile(const std::string &path);
bool CanExecuteFile(const Path &path);
// Returns true if `path` exists, is a directory or symlink/junction to one, and
// is both readable and writable.
// Follows symlinks/junctions.
bool CanAccessDirectory(const std::string &path);
bool CanAccessDirectory(const Path &path);
// Returns true if `path` refers to a directory or a symlink/junction to one.
bool IsDirectory(const std::string& path);
bool IsDirectory(const Path &path);
// Calls fsync() on the file (or directory) specified in 'file_path'.
// pdie() if syncing fails.
void SyncFile(const std::string& path);
void SyncFile(const Path &path);
// mkdir -p path. All newly created directories use the given mode.
// `mode` should be an octal permission mask, e.g. 0755.
// Returns false on failure, sets errno.
bool MakeDirectories(const std::string &path, unsigned int mode);
bool MakeDirectories(const Path &path, unsigned int mode);
// Creates a directory starting with prefix for temporary usage. The directory
// name is guaranteed to be at least unique to this process.
std::string CreateTempDir(const std::string &prefix);
// Removes the specified path or directory, and in the latter case, all of its
// contents. Returns true iff the path doesn't exists when the method completes
// (including if the path didn't exist to begin with). Does not follow symlinks.
bool RemoveRecursively(const std::string &path);
// Returns the current working directory.
// The path is platform-specific (e.g. Windows path of Windows) and absolute.
std::string GetCwd();
// Changes the current working directory to `path`, returns true upon success.
bool ChangeDirectory(const std::string& path);
// Interface to be implemented by ForEachDirectoryEntry clients.
class DirectoryEntryConsumer {
public:
virtual ~DirectoryEntryConsumer() {}
// This method is called for each entry in a directory.
// `name` is the full path of the entry.
// `is_directory` is true if this entry is a directory (but false if this is a
// symlink pointing to a directory).
virtual void Consume(const std::string &name, bool is_directory) = 0;
};
// Executes a function for each entry in a directory (except "." and "..").
//
// Returns true if the `path` referred to a directory or directory symlink,
// false otherwise.
//
// See DirectoryEntryConsumer for more details.
void ForEachDirectoryEntry(const std::string &path,
DirectoryEntryConsumer *consume);
#if defined(_WIN32) || defined(__CYGWIN__)
std::wstring GetCwdW();
bool MakeDirectoriesW(const std::wstring &path, unsigned int mode);
// Check if `path` is a directory.
bool IsDirectoryW(const std::wstring &path);
// Interface to be implemented by ForEachDirectoryEntryW clients.
class DirectoryEntryConsumerW {
public:
virtual ~DirectoryEntryConsumerW() {}
// This method is called for each entry in a directory.
// `name` is the full path of the entry.
// `is_directory` is true if this entry is a directory (but false if this is a
// symlink pointing to a directory).
virtual void Consume(const std::wstring &name, bool is_directory) = 0;
};
// Lists all files in `path` and all of its subdirectories.
//
// Does not follow symlinks / junctions.
//
// Populates `result` with the full paths of the files. Every entry will have
// `path` as its prefix. If `path` is a file, `result` contains just this
// file.
void GetAllFilesUnderW(const std::wstring &path,
std::vector<std::wstring> *result);
// Visible for testing only.
typedef void (*_ForEachDirectoryEntryW)(const std::wstring &path,
DirectoryEntryConsumerW *consume);
// Visible for testing only.
void _GetAllFilesUnderW(const std::wstring &path,
std::vector<std::wstring> *result,
_ForEachDirectoryEntryW walk_entries);
#endif // defined(_WIN32) || defined(__CYGWIN__)
} // namespace blaze_util
#endif // BAZEL_SRC_MAIN_CPP_UTIL_FILE_PLATFORM_H_