You cannot select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

479 lines
14 KiB
C

3 months ago
// Formatting library for C++ - optional OS-specific functionality
//
// Copyright (c) 2012 - present, Victor Zverovich
// All rights reserved.
//
// For the license information refer to format.h.
#ifndef FMT_OS_H_
#define FMT_OS_H_
#include <cerrno>
#include <cstddef>
#include <cstdio>
#include <system_error> // std::system_error
#if defined __APPLE__ || defined(__FreeBSD__)
# include <xlocale.h> // for LC_NUMERIC_MASK on OS X
#endif
#include "format.h"
#ifndef FMT_USE_FCNTL
// UWP doesn't provide _pipe.
# if FMT_HAS_INCLUDE("winapifamily.h")
# include <winapifamily.h>
# endif
# if (FMT_HAS_INCLUDE(<fcntl.h>) || defined(__APPLE__) || \
defined(__linux__)) && \
(!defined(WINAPI_FAMILY) || \
(WINAPI_FAMILY == WINAPI_FAMILY_DESKTOP_APP))
# include <fcntl.h> // for O_RDONLY
# define FMT_USE_FCNTL 1
# else
# define FMT_USE_FCNTL 0
# endif
#endif
#ifndef FMT_POSIX
# if defined(_WIN32) && !defined(__MINGW32__)
// Fix warnings about deprecated symbols.
# define FMT_POSIX(call) _##call
# else
# define FMT_POSIX(call) call
# endif
#endif
// Calls to system functions are wrapped in FMT_SYSTEM for testability.
#ifdef FMT_SYSTEM
# define FMT_POSIX_CALL(call) FMT_SYSTEM(call)
#else
# define FMT_SYSTEM(call) ::call
# ifdef _WIN32
// Fix warnings about deprecated symbols.
# define FMT_POSIX_CALL(call) ::_##call
# else
# define FMT_POSIX_CALL(call) ::call
# endif
#endif
// Retries the expression while it evaluates to error_result and errno
// equals to EINTR.
#ifndef _WIN32
# define FMT_RETRY_VAL(result, expression, error_result) \
do { \
(result) = (expression); \
} while ((result) == (error_result) && errno == EINTR)
#else
# define FMT_RETRY_VAL(result, expression, error_result) result = (expression)
#endif
#define FMT_RETRY(result, expression) FMT_RETRY_VAL(result, expression, -1)
FMT_BEGIN_NAMESPACE
FMT_MODULE_EXPORT_BEGIN
/**
\rst
A reference to a null-terminated string. It can be constructed from a C
string or ``std::string``.
You can use one of the following type aliases for common character types:
+---------------+-----------------------------+
| Type | Definition |
+===============+=============================+
| cstring_view | basic_cstring_view<char> |
+---------------+-----------------------------+
| wcstring_view | basic_cstring_view<wchar_t> |
+---------------+-----------------------------+
This class is most useful as a parameter type to allow passing
different types of strings to a function, for example::
template <typename... Args>
std::string format(cstring_view format_str, const Args & ... args);
format("{}", 42);
format(std::string("{}"), 42);
\endrst
*/
template <typename Char> class basic_cstring_view {
private:
const Char* data_;
public:
/** Constructs a string reference object from a C string. */
basic_cstring_view(const Char* s) : data_(s) {}
/**
\rst
Constructs a string reference from an ``std::string`` object.
\endrst
*/
basic_cstring_view(const std::basic_string<Char>& s) : data_(s.c_str()) {}
/** Returns the pointer to a C string. */
const Char* c_str() const { return data_; }
};
using cstring_view = basic_cstring_view<char>;
using wcstring_view = basic_cstring_view<wchar_t>;
template <typename Char> struct formatter<std::error_code, Char> {
template <typename ParseContext>
FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
return ctx.begin();
}
template <typename FormatContext>
FMT_CONSTEXPR auto format(const std::error_code& ec, FormatContext& ctx) const
-> decltype(ctx.out()) {
auto out = ctx.out();
out = detail::write_bytes(out, ec.category().name(),
basic_format_specs<Char>());
out = detail::write<Char>(out, Char(':'));
out = detail::write<Char>(out, ec.value());
return out;
}
};
#ifdef _WIN32
FMT_API const std::error_category& system_category() noexcept;
FMT_BEGIN_DETAIL_NAMESPACE
// A converter from UTF-16 to UTF-8.
// It is only provided for Windows since other systems support UTF-8 natively.
class utf16_to_utf8 {
private:
memory_buffer buffer_;
public:
utf16_to_utf8() {}
FMT_API explicit utf16_to_utf8(basic_string_view<wchar_t> s);
operator string_view() const { return string_view(&buffer_[0], size()); }
size_t size() const { return buffer_.size() - 1; }
const char* c_str() const { return &buffer_[0]; }
std::string str() const { return std::string(&buffer_[0], size()); }
// Performs conversion returning a system error code instead of
// throwing exception on conversion error. This method may still throw
// in case of memory allocation error.
FMT_API int convert(basic_string_view<wchar_t> s);
};
FMT_API void format_windows_error(buffer<char>& out, int error_code,
const char* message) noexcept;
FMT_END_DETAIL_NAMESPACE
FMT_API std::system_error vwindows_error(int error_code, string_view format_str,
format_args args);
/**
\rst
Constructs a :class:`std::system_error` object with the description
of the form
.. parsed-literal::
*<message>*: *<system-message>*
where *<message>* is the formatted message and *<system-message>* is the
system message corresponding to the error code.
*error_code* is a Windows error code as given by ``GetLastError``.
If *error_code* is not a valid error code such as -1, the system message
will look like "error -1".
**Example**::
// This throws a system_error with the description
// cannot open file 'madeup': The system cannot find the file specified.
// or similar (system message may vary).
const char *filename = "madeup";
LPOFSTRUCT of = LPOFSTRUCT();
HFILE file = OpenFile(filename, &of, OF_READ);
if (file == HFILE_ERROR) {
throw fmt::windows_error(GetLastError(),
"cannot open file '{}'", filename);
}
\endrst
*/
template <typename... Args>
std::system_error windows_error(int error_code, string_view message,
const Args&... args) {
return vwindows_error(error_code, message, fmt::make_format_args(args...));
}
// Reports a Windows error without throwing an exception.
// Can be used to report errors from destructors.
FMT_API void report_windows_error(int error_code, const char* message) noexcept;
#else
inline const std::error_category& system_category() noexcept {
return std::system_category();
}
#endif // _WIN32
// std::system is not available on some platforms such as iOS (#2248).
#ifdef __OSX__
template <typename S, typename... Args, typename Char = char_t<S>>
void say(const S& format_str, Args&&... args) {
std::system(format("say \"{}\"", format(format_str, args...)).c_str());
}
#endif
// A buffered file.
class buffered_file {
private:
FILE* file_;
friend class file;
explicit buffered_file(FILE* f) : file_(f) {}
public:
buffered_file(const buffered_file&) = delete;
void operator=(const buffered_file&) = delete;
// Constructs a buffered_file object which doesn't represent any file.
buffered_file() noexcept : file_(nullptr) {}
// Destroys the object closing the file it represents if any.
FMT_API ~buffered_file() noexcept;
public:
buffered_file(buffered_file&& other) noexcept : file_(other.file_) {
other.file_ = nullptr;
}
buffered_file& operator=(buffered_file&& other) {
close();
file_ = other.file_;
other.file_ = nullptr;
return *this;
}
// Opens a file.
FMT_API buffered_file(cstring_view filename, cstring_view mode);
// Closes the file.
FMT_API void close();
// Returns the pointer to a FILE object representing this file.
FILE* get() const noexcept { return file_; }
FMT_API int descriptor() const;
void vprint(string_view format_str, format_args args) {
fmt::vprint(file_, format_str, args);
}
template <typename... Args>
inline void print(string_view format_str, const Args&... args) {
vprint(format_str, fmt::make_format_args(args...));
}
};
#if FMT_USE_FCNTL
// A file. Closed file is represented by a file object with descriptor -1.
// Methods that are not declared with noexcept may throw
// fmt::system_error in case of failure. Note that some errors such as
// closing the file multiple times will cause a crash on Windows rather
// than an exception. You can get standard behavior by overriding the
// invalid parameter handler with _set_invalid_parameter_handler.
class FMT_API file {
private:
int fd_; // File descriptor.
// Constructs a file object with a given descriptor.
explicit file(int fd) : fd_(fd) {}
public:
// Possible values for the oflag argument to the constructor.
enum {
RDONLY = FMT_POSIX(O_RDONLY), // Open for reading only.
WRONLY = FMT_POSIX(O_WRONLY), // Open for writing only.
RDWR = FMT_POSIX(O_RDWR), // Open for reading and writing.
CREATE = FMT_POSIX(O_CREAT), // Create if the file doesn't exist.
APPEND = FMT_POSIX(O_APPEND), // Open in append mode.
TRUNC = FMT_POSIX(O_TRUNC) // Truncate the content of the file.
};
// Constructs a file object which doesn't represent any file.
file() noexcept : fd_(-1) {}
// Opens a file and constructs a file object representing this file.
file(cstring_view path, int oflag);
public:
file(const file&) = delete;
void operator=(const file&) = delete;
file(file&& other) noexcept : fd_(other.fd_) { other.fd_ = -1; }
// Move assignment is not noexcept because close may throw.
file& operator=(file&& other) {
close();
fd_ = other.fd_;
other.fd_ = -1;
return *this;
}
// Destroys the object closing the file it represents if any.
~file() noexcept;
// Returns the file descriptor.
int descriptor() const noexcept { return fd_; }
// Closes the file.
void close();
// Returns the file size. The size has signed type for consistency with
// stat::st_size.
long long size() const;
// Attempts to read count bytes from the file into the specified buffer.
size_t read(void* buffer, size_t count);
// Attempts to write count bytes from the specified buffer to the file.
size_t write(const void* buffer, size_t count);
// Duplicates a file descriptor with the dup function and returns
// the duplicate as a file object.
static file dup(int fd);
// Makes fd be the copy of this file descriptor, closing fd first if
// necessary.
void dup2(int fd);
// Makes fd be the copy of this file descriptor, closing fd first if
// necessary.
void dup2(int fd, std::error_code& ec) noexcept;
// Creates a pipe setting up read_end and write_end file objects for reading
// and writing respectively.
static void pipe(file& read_end, file& write_end);
// Creates a buffered_file object associated with this file and detaches
// this file object from the file.
buffered_file fdopen(const char* mode);
};
// Returns the memory page size.
long getpagesize();
FMT_BEGIN_DETAIL_NAMESPACE
struct buffer_size {
buffer_size() = default;
size_t value = 0;
buffer_size operator=(size_t val) const {
auto bs = buffer_size();
bs.value = val;
return bs;
}
};
struct ostream_params {
int oflag = file::WRONLY | file::CREATE | file::TRUNC;
size_t buffer_size = BUFSIZ > 32768 ? BUFSIZ : 32768;
ostream_params() {}
template <typename... T>
ostream_params(T... params, int new_oflag) : ostream_params(params...) {
oflag = new_oflag;
}
template <typename... T>
ostream_params(T... params, detail::buffer_size bs)
: ostream_params(params...) {
this->buffer_size = bs.value;
}
// Intel has a bug that results in failure to deduce a constructor
// for empty parameter packs.
# if defined(__INTEL_COMPILER) && __INTEL_COMPILER < 2000
ostream_params(int new_oflag) : oflag(new_oflag) {}
ostream_params(detail::buffer_size bs) : buffer_size(bs.value) {}
# endif
};
FMT_END_DETAIL_NAMESPACE
// Added {} below to work around default constructor error known to
// occur in Xcode versions 7.2.1 and 8.2.1.
constexpr detail::buffer_size buffer_size{};
/** A fast output stream which is not thread-safe. */
class FMT_API ostream final : private detail::buffer<char> {
private:
file file_;
void grow(size_t) override;
ostream(cstring_view path, const detail::ostream_params& params)
: file_(path, params.oflag) {
set(new char[params.buffer_size], params.buffer_size);
}
public:
ostream(ostream&& other)
: detail::buffer<char>(other.data(), other.size(), other.capacity()),
file_(std::move(other.file_)) {
other.clear();
other.set(nullptr, 0);
}
~ostream() {
flush();
delete[] data();
}
void flush() {
if (size() == 0) return;
file_.write(data(), size());
clear();
}
template <typename... T>
friend ostream output_file(cstring_view path, T... params);
void close() {
flush();
file_.close();
}
/**
Formats ``args`` according to specifications in ``fmt`` and writes the
output to the file.
*/
template <typename... T> void print(format_string<T...> fmt, T&&... args) {
vformat_to(detail::buffer_appender<char>(*this), fmt,
fmt::make_format_args(args...));
}
};
/**
\rst
Opens a file for writing. Supported parameters passed in *params*:
* ``<integer>``: Flags passed to `open
<https://pubs.opengroup.org/onlinepubs/007904875/functions/open.html>`_
(``file::WRONLY | file::CREATE | file::TRUNC`` by default)
* ``buffer_size=<integer>``: Output buffer size
**Example**::
auto out = fmt::output_file("guide.txt");
out.print("Don't {}", "Panic");
\endrst
*/
template <typename... T>
inline ostream output_file(cstring_view path, T... params) {
return {path, detail::ostream_params(params...)};
}
#endif // FMT_USE_FCNTL
FMT_MODULE_EXPORT_END
FMT_END_NAMESPACE
#endif // FMT_OS_H_