fmt/format.cc

/*
 Formatting library for C++

 Copyright (c) 2012 - 2016, Victor Zverovich
 All rights reserved.

 Redistribution and use in source and binary forms, with or without
 modification, are permitted provided that the following conditions are met:

 1. Redistributions of source code must retain the above copyright notice, this
    list of conditions and the following disclaimer.
 2. Redistributions in binary form must reproduce the above copyright notice,
    this list of conditions and the following disclaimer in the documentation
    and/or other materials provided with the distribution.

 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
 ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "fmt/format.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(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

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

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

void format_error_code(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);
  basic_writer<char> 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

FMT_FUNC void system_error::init(
    int err_code, string_view format_str, 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
};

FMT_FUNC void internal::report_unknown_type(char code, const char *type) {
  (void)type;
  if (std::isprint(static_cast<unsigned char>(code))) {
    FMT_THROW(format_error(
        format("unknown format code '{}' for {}", code, type)));
  }
  FMT_THROW(format_error(
      format("unknown format code '\\x{:02x}' for {}",
        static_cast<unsigned>(code), type)));
}

#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, 0, 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, 0, 0, 0, 0);
  if (length == 0)
    return GetLastError();
  buffer_.resize(length + 1);
  length = WideCharToMultiByte(
    CP_UTF8, 0, s.data(), s_size, &buffer_[0], length, 0, 0);
  if (length == 0)
    return GetLastError();
  buffer_[length] = 0;
  return 0;
}

FMT_FUNC void windows_error::init(
    int err_code, string_view format_str, 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(
    buffer &out, int error_code, string_view message) FMT_NOEXCEPT {
  FMT_TRY {
    wmemory_buffer buffer;
    buffer.resize(INLINE_BUFFER_SIZE);
    for (;;) {
      wchar_t *system_message = &buffer[0];
      int result = FormatMessageW(
          FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
          0, error_code, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
          system_message, static_cast<uint32_t>(buffer.size()), 0);
      if (result != 0) {
        utf16_to_utf8 utf8_message;
        if (utf8_message.convert(system_message) == ERROR_SUCCESS) {
          basic_writer<char> 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.
      buffer.resize(buffer.size() * 2);
    }
  } FMT_CATCH(...) {}
  fmt::format_error_code(out, error_code, message);  // 'fmt::' is for bcc32.
}

#endif  // FMT_USE_WINDOWS_H

FMT_FUNC void format_system_error(
    buffer &out, int error_code, string_view message) FMT_NOEXCEPT {
  FMT_TRY {
    memory_buffer buffer;
    buffer.resize(internal::INLINE_BUFFER_SIZE);
    for (;;) {
      char *system_message = &buffer[0];
      int result = safe_strerror(error_code, system_message, buffer.size());
      if (result == 0) {
        basic_writer<char> 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.
      buffer.resize(buffer.size() * 2);
    }
  } FMT_CATCH(...) {}
  fmt::format_error_code(out, error_code, message);  // 'fmt::' is for bcc32.
}

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

FMT_FUNC void report_system_error(
    int error_code, fmt::string_view message) FMT_NOEXCEPT {
  // 'fmt::' is for bcc32.
  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 {
  // 'fmt::' is for bcc32.
  report_error(internal::format_windows_error, error_code, message);
}
#endif

FMT_FUNC void vprint(std::FILE *f, string_view format_str, 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, args args) {
  vprint(stdout, format_str, args);
}

FMT_FUNC void vprint_colored(Color c, string_view 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);
}

#ifndef FMT_HEADER_ONLY

template struct internal::basic_data<void>;

// Explicit instantiations for char.

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

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

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

template 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 class basic_context<wchar_t>;

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

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

template 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 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