include/fmt/format.cc

// Formatting library for C++
//
// Copyright (c) 2012 - 2016, Victor Zverovich
// All rights reserved.
//
// For the license information refer to format.h.

#include "format.h"
#include "locale.h"

#include <string.h>

#include <cctype>
#include <cerrno>
#include <climits>
#include <cmath>
#include <cstdarg>
#include <cstddef>  // for std::ptrdiff_t

#if defined(_WIN32) && defined(__MINGW32__)
# include <cstring>
#endif

#if FMT_USE_WINDOWS_H
# if !defined(FMT_HEADER_ONLY) && !defined(WIN32_LEAN_AND_MEAN)
#  define WIN32_LEAN_AND_MEAN
# endif
# if defined(NOMINMAX) || defined(FMT_WIN_MINMAX)
#  include <windows.h>
# else
#  define NOMINMAX
#  include <windows.h>
#  undef NOMINMAX
# endif
#endif

#if FMT_EXCEPTIONS
# define FMT_TRY try
# define FMT_CATCH(x) catch (x)
#else
# define FMT_TRY if (true)
# define FMT_CATCH(x) if (false)
#endif

#ifdef __GNUC__
// Disable the warning about declaration shadowing because it affects too
// many valid cases.
# pragma GCC diagnostic ignored "-Wshadow"
#endif

#ifdef _MSC_VER
# pragma warning(push)
# pragma warning(disable: 4127)  // conditional expression is constant
# pragma warning(disable: 4702)  // unreachable code
// Disable deprecation warning for strerror. The latter is not called but
// MSVC fails to detect it.
# pragma warning(disable: 4996)
#endif

// Dummy implementations of strerror_r and strerror_s called if corresponding
// system functions are not available.
static inline fmt::internal::null<> strerror_r(int, char *, ...) {
  return fmt::internal::null<>();
}
static inline fmt::internal::null<> strerror_s(char *, std::size_t, ...) {
  return fmt::internal::null<>();
}

namespace fmt {

FMT_FUNC format_error::~format_error() throw() {}
FMT_FUNC system_error::~system_error() throw() {}

namespace {

#ifndef _MSC_VER
# define FMT_SNPRINTF snprintf
#else  // _MSC_VER
inline int fmt_snprintf(char *buffer, size_t size, const char *format, ...) {
  va_list args;
  va_start(args, format);
  int result = vsnprintf_s(buffer, size, _TRUNCATE, format, args);
  va_end(args);
  return result;
}
# define FMT_SNPRINTF fmt_snprintf
#endif  // _MSC_VER

#if defined(_WIN32) && defined(__MINGW32__) && !defined(__NO_ISOCEXT)
# define FMT_SWPRINTF snwprintf
#else
# define FMT_SWPRINTF swprintf
#endif // defined(_WIN32) && defined(__MINGW32__) && !defined(__NO_ISOCEXT)

const char RESET_COLOR[] = "\x1b[0m";

typedef void (*FormatFunc)(internal::buffer &, int, string_view);

// Portable thread-safe version of strerror.
// Sets buffer to point to a string describing the error code.
// This can be either a pointer to a string stored in buffer,
// or a pointer to some static immutable string.
// Returns one of the following values:
//   0      - success
//   ERANGE - buffer is not large enough to store the error message
//   other  - failure
// Buffer should be at least of size 1.
int safe_strerror(
    int error_code, char *&buffer, std::size_t buffer_size) FMT_NOEXCEPT {
  FMT_ASSERT(buffer != FMT_NULL && buffer_size != 0, "invalid buffer");

  class StrError {
   private:
    int error_code_;
    char *&buffer_;
    std::size_t buffer_size_;

    // A noop assignment operator to avoid bogus warnings.
    void operator=(const StrError &) {}

    // Handle the result of XSI-compliant version of strerror_r.
    int handle(int result) {
      // glibc versions before 2.13 return result in errno.
      return result == -1 ? errno : result;
    }

    // Handle the result of GNU-specific version of strerror_r.
    int handle(char *message) {
      // If the buffer is full then the message is probably truncated.
      if (message == buffer_ && strlen(buffer_) == buffer_size_ - 1)
        return ERANGE;
      buffer_ = message;
      return 0;
    }

    // Handle the case when strerror_r is not available.
    int handle(internal::null<>) {
      return fallback(strerror_s(buffer_, buffer_size_, error_code_));
    }

    // Fallback to strerror_s when strerror_r is not available.
    int fallback(int result) {
      // If the buffer is full then the message is probably truncated.
      return result == 0 && strlen(buffer_) == buffer_size_ - 1 ?
            ERANGE : result;
    }

    // Fallback to strerror if strerror_r and strerror_s are not available.
    int fallback(internal::null<>) {
      errno = 0;
      buffer_ = strerror(error_code_);
      return errno;
    }

   public:
    StrError(int err_code, char *&buf, std::size_t buf_size)
      : error_code_(err_code), buffer_(buf), buffer_size_(buf_size) {}

    int run() {
      // Suppress a warning about unused strerror_r.
      strerror_r(0, FMT_NULL, "");
      return handle(strerror_r(error_code_, buffer_, buffer_size_));
    }
  };
  return StrError(error_code, buffer, buffer_size).run();
}

void format_error_code(internal::buffer &out, int error_code,
                       string_view message) FMT_NOEXCEPT {
  // Report error code making sure that the output fits into
  // INLINE_BUFFER_SIZE to avoid dynamic memory allocation and potential
  // bad_alloc.
  out.resize(0);
  static const char SEP[] = ": ";
  static const char ERROR_STR[] = "error ";
  // Subtract 2 to account for terminating null characters in SEP and ERROR_STR.
  std::size_t error_code_size = sizeof(SEP) + sizeof(ERROR_STR) - 2;
  typedef internal::int_traits<int>::main_type main_type;
  main_type abs_value = static_cast<main_type>(error_code);
  if (internal::is_negative(error_code)) {
    abs_value = 0 - abs_value;
    ++error_code_size;
  }
  error_code_size += internal::count_digits(abs_value);
  writer w(out);
  if (message.size() <= internal::INLINE_BUFFER_SIZE - error_code_size) {
    w.write(message);
    w.write(SEP);
  }
  w.write(ERROR_STR);
  w.write(error_code);
  assert(out.size() <= internal::INLINE_BUFFER_SIZE);
}

void report_error(FormatFunc func, int error_code,
                  string_view message) FMT_NOEXCEPT {
  memory_buffer full_message;
  func(full_message, error_code, message);
  // Use Writer::data instead of Writer::c_str to avoid potential memory
  // allocation.
  std::fwrite(full_message.data(), full_message.size(), 1, stderr);
  std::fputc('\n', stderr);
}
}  // namespace

template <typename Char>
FMT_FUNC Char internal::thousands_sep(locale_provider *lp) {
  std::locale loc = lp ? lp->locale().get() : std::locale();
  return std::use_facet<std::numpunct<Char>>(loc).thousands_sep();
}

FMT_FUNC void system_error::init(
    int err_code, string_view format_str, format_args args) {
  error_code_ = err_code;
  memory_buffer buffer;
  format_system_error(buffer, err_code, vformat(format_str, args));
  std::runtime_error &base = *this;
  base = std::runtime_error(to_string(buffer));
}

template <typename T>
int internal::char_traits<char>::format_float(
    char *buffer, std::size_t size, const char *format,
    unsigned width, int precision, T value) {
  if (width == 0) {
    return precision < 0 ?
        FMT_SNPRINTF(buffer, size, format, value) :
        FMT_SNPRINTF(buffer, size, format, precision, value);
  }
  return precision < 0 ?
      FMT_SNPRINTF(buffer, size, format, width, value) :
      FMT_SNPRINTF(buffer, size, format, width, precision, value);
}

template <typename T>
int internal::char_traits<wchar_t>::format_float(
    wchar_t *buffer, std::size_t size, const wchar_t *format,
    unsigned width, int precision, T value) {
  if (width == 0) {
    return precision < 0 ?
        FMT_SWPRINTF(buffer, size, format, value) :
        FMT_SWPRINTF(buffer, size, format, precision, value);
  }
  return precision < 0 ?
      FMT_SWPRINTF(buffer, size, format, width, value) :
      FMT_SWPRINTF(buffer, size, format, width, precision, value);
}

template <typename T>
const char internal::basic_data<T>::DIGITS[] =
    "0001020304050607080910111213141516171819"
    "2021222324252627282930313233343536373839"
    "4041424344454647484950515253545556575859"
    "6061626364656667686970717273747576777879"
    "8081828384858687888990919293949596979899";

#define FMT_POWERS_OF_10(factor) \
  factor * 10, \
  factor * 100, \
  factor * 1000, \
  factor * 10000, \
  factor * 100000, \
  factor * 1000000, \
  factor * 10000000, \
  factor * 100000000, \
  factor * 1000000000

template <typename T>
const uint32_t internal::basic_data<T>::POWERS_OF_10_32[] = {
  0, FMT_POWERS_OF_10(1)
};

template <typename T>
const uint64_t internal::basic_data<T>::POWERS_OF_10_64[] = {
  0,
  FMT_POWERS_OF_10(1),
  FMT_POWERS_OF_10(1000000000ull),
  10000000000000000000ull
};

#if FMT_USE_WINDOWS_H

FMT_FUNC internal::utf8_to_utf16::utf8_to_utf16(string_view s) {
  static const char ERROR_MSG[] = "cannot convert string from UTF-8 to UTF-16";
  if (s.size() > INT_MAX)
    FMT_THROW(windows_error(ERROR_INVALID_PARAMETER, ERROR_MSG));
  int s_size = static_cast<int>(s.size());
  int length = MultiByteToWideChar(
      CP_UTF8, MB_ERR_INVALID_CHARS, s.data(), s_size, FMT_NULL, 0);
  if (length == 0)
    FMT_THROW(windows_error(GetLastError(), ERROR_MSG));
  buffer_.resize(length + 1);
  length = MultiByteToWideChar(
    CP_UTF8, MB_ERR_INVALID_CHARS, s.data(), s_size, &buffer_[0], length);
  if (length == 0)
    FMT_THROW(windows_error(GetLastError(), ERROR_MSG));
  buffer_[length] = 0;
}

FMT_FUNC internal::utf16_to_utf8::utf16_to_utf8(wstring_view s) {
  if (int error_code = convert(s)) {
    FMT_THROW(windows_error(error_code,
        "cannot convert string from UTF-16 to UTF-8"));
  }
}

FMT_FUNC int internal::utf16_to_utf8::convert(wstring_view s) {
  if (s.size() > INT_MAX)
    return ERROR_INVALID_PARAMETER;
  int s_size = static_cast<int>(s.size());
  int length = WideCharToMultiByte(
        CP_UTF8, 0, s.data(), s_size, FMT_NULL, 0, FMT_NULL, FMT_NULL);
  if (length == 0)
    return GetLastError();
  buffer_.resize(length + 1);
  length = WideCharToMultiByte(
    CP_UTF8, 0, s.data(), s_size, &buffer_[0], length, FMT_NULL, FMT_NULL);
  if (length == 0)
    return GetLastError();
  buffer_[length] = 0;
  return 0;
}

FMT_FUNC void windows_error::init(
    int err_code, string_view format_str, format_args args) {
  error_code_ = err_code;
  memory_buffer buffer;
  internal::format_windows_error(buffer, err_code, vformat(format_str, args));
  std::runtime_error &base = *this;
  base = std::runtime_error(to_string(buffer));
}

FMT_FUNC void internal::format_windows_error(
    internal::buffer &out, int error_code, string_view message) FMT_NOEXCEPT {
  FMT_TRY {
    wmemory_buffer buf;
    buf.resize(INLINE_BUFFER_SIZE);
    for (;;) {
      wchar_t *system_message = &buf[0];
      int result = FormatMessageW(
          FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
          FMT_NULL, error_code, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
          system_message, static_cast<uint32_t>(buf.size()), FMT_NULL);
      if (result != 0) {
        utf16_to_utf8 utf8_message;
        if (utf8_message.convert(system_message) == ERROR_SUCCESS) {
          writer w(out);
          w.write(message);
          w.write(": ");
          w.write(utf8_message);
          return;
        }
        break;
      }
      if (GetLastError() != ERROR_INSUFFICIENT_BUFFER)
        break;  // Can't get error message, report error code instead.
      buf.resize(buf.size() * 2);
    }
  } FMT_CATCH(...) {}
  format_error_code(out, error_code, message);
}

#endif  // FMT_USE_WINDOWS_H

FMT_FUNC void format_system_error(
    internal::buffer &out, int error_code, string_view message) FMT_NOEXCEPT {
  FMT_TRY {
    memory_buffer buf;
    buf.resize(internal::INLINE_BUFFER_SIZE);
    for (;;) {
      char *system_message = &buf[0];
      int result = safe_strerror(error_code, system_message, buf.size());
      if (result == 0) {
        writer w(out);
        w.write(message);
        w.write(": ");
        w.write(system_message);
        return;
      }
      if (result != ERANGE)
        break;  // Can't get error message, report error code instead.
      buf.resize(buf.size() * 2);
    }
  } FMT_CATCH(...) {}
  format_error_code(out, error_code, message);
}

template <typename Char>
void basic_fixed_buffer<Char>::grow(std::size_t) {
  FMT_THROW(std::runtime_error("buffer overflow"));
}

FMT_FUNC void internal::error_handler::on_error(const char *message) {
  FMT_THROW(format_error(message));
}

FMT_FUNC void report_system_error(
    int error_code, fmt::string_view message) FMT_NOEXCEPT {
  report_error(format_system_error, error_code, message);
}

#if FMT_USE_WINDOWS_H
FMT_FUNC void report_windows_error(
    int error_code, fmt::string_view message) FMT_NOEXCEPT {
  report_error(internal::format_windows_error, error_code, message);
}
#endif

FMT_FUNC void vprint(std::FILE *f, string_view format_str, format_args args) {
  memory_buffer buffer;
  vformat_to(buffer, format_str, args);
  std::fwrite(buffer.data(), 1, buffer.size(), f);
}

FMT_FUNC void vprint(string_view format_str, format_args args) {
  vprint(stdout, format_str, args);
}

FMT_FUNC void vprint_colored(Color c, string_view format, format_args args) {
  char escape[] = "\x1b[30m";
  escape[3] = static_cast<char>('0' + c);
  std::fputs(escape, stdout);
  vprint(format, args);
  std::fputs(RESET_COLOR, stdout);
}

FMT_FUNC locale locale_provider::locale() { return fmt::locale(); }

#ifndef FMT_HEADER_ONLY

template struct internal::basic_data<void>;

// Explicit instantiations for char.

template char internal::thousands_sep(locale_provider *lp);

template void basic_fixed_buffer<char>::grow(std::size_t);

template void internal::arg_map<context>::init(const format_args &args);

template FMT_API int internal::char_traits<char>::format_float(
    char *buffer, std::size_t size, const char *format,
    unsigned width, int precision, double value);

template FMT_API int internal::char_traits<char>::format_float(
    char *buffer, std::size_t size, const char *format,
    unsigned width, int precision, long double value);

// Explicit instantiations for wchar_t.

template wchar_t internal::thousands_sep(locale_provider *lp);

template void basic_fixed_buffer<wchar_t>::grow(std::size_t);

template void internal::arg_map<wcontext>::init(const wformat_args &args);

template FMT_API int internal::char_traits<wchar_t>::format_float(
    wchar_t *buffer, std::size_t size, const wchar_t *format,
    unsigned width, int precision, double value);

template FMT_API int internal::char_traits<wchar_t>::format_float(
    wchar_t *buffer, std::size_t size, const wchar_t *format,
    unsigned width, int precision, long double value);

#endif  // FMT_HEADER_ONLY

}  // namespace fmt

#ifdef _MSC_VER
# pragma warning(pop)
#endif