// Formatting library for C++ // // Copyright (c) 2012 - 2016, Victor Zverovich // All rights reserved. // // For the license information refer to format.h. #ifndef FMT_PRINTF_H_ #define FMT_PRINTF_H_ #include // std::fill_n #include // std::numeric_limits #include "ostream.h" FMT_BEGIN_NAMESPACE namespace internal { // An iterator that produces a null terminator on *end. This simplifies parsing // and allows comparing the performance of processing a null-terminated string // vs string_view. template class null_terminating_iterator { public: typedef std::ptrdiff_t difference_type; typedef Char value_type; typedef const Char* pointer; typedef const Char& reference; typedef std::random_access_iterator_tag iterator_category; null_terminating_iterator() : ptr_(0), end_(0) {} FMT_CONSTEXPR null_terminating_iterator(const Char *ptr, const Char *end) : ptr_(ptr), end_(end) {} template FMT_CONSTEXPR explicit null_terminating_iterator(const Range &r) : ptr_(r.begin()), end_(r.end()) {} FMT_CONSTEXPR null_terminating_iterator &operator=(const Char *ptr) { assert(ptr <= end_); ptr_ = ptr; return *this; } FMT_CONSTEXPR Char operator*() const { return ptr_ != end_ ? *ptr_ : Char(); } FMT_CONSTEXPR null_terminating_iterator operator++() { ++ptr_; return *this; } FMT_CONSTEXPR null_terminating_iterator operator++(int) { null_terminating_iterator result(*this); ++ptr_; return result; } FMT_CONSTEXPR null_terminating_iterator operator--() { --ptr_; return *this; } FMT_CONSTEXPR null_terminating_iterator operator+(difference_type n) { return null_terminating_iterator(ptr_ + n, end_); } FMT_CONSTEXPR null_terminating_iterator operator-(difference_type n) { return null_terminating_iterator(ptr_ - n, end_); } FMT_CONSTEXPR null_terminating_iterator operator+=(difference_type n) { ptr_ += n; return *this; } FMT_CONSTEXPR difference_type operator-( null_terminating_iterator other) const { return ptr_ - other.ptr_; } FMT_CONSTEXPR bool operator!=(null_terminating_iterator other) const { return ptr_ != other.ptr_; } bool operator>=(null_terminating_iterator other) const { return ptr_ >= other.ptr_; } // This should be a friend specialization pointer_from but the latter // doesn't compile by gcc 5.1 due to a compiler bug. template friend FMT_CONSTEXPR_DECL const CharT *pointer_from( null_terminating_iterator it); private: const Char *ptr_; const Char *end_; }; template FMT_CONSTEXPR const T *pointer_from(const T *p) { return p; } template FMT_CONSTEXPR const Char *pointer_from(null_terminating_iterator it) { return it.ptr_; } // DEPRECATED: Parses the input as an unsigned integer. This function assumes // that the first character is a digit and presence of a non-digit character at // the end. // it: an iterator pointing to the beginning of the input range. template FMT_CONSTEXPR unsigned parse_nonnegative_int(Iterator &it, ErrorHandler &&eh) { assert('0' <= *it && *it <= '9'); if (*it == '0') { ++it; return 0; } unsigned value = 0; // Convert to unsigned to prevent a warning. unsigned max_int = (std::numeric_limits::max)(); unsigned big = max_int / 10; do { // Check for overflow. if (value > big) { value = max_int + 1; break; } value = value * 10 + unsigned(*it - '0'); // Workaround for MSVC "setup_exception stack overflow" error: auto next = it; ++next; it = next; } while ('0' <= *it && *it <= '9'); if (value > max_int) eh.on_error("number is too big"); return value; } // Checks if a value fits in int - used to avoid warnings about comparing // signed and unsigned integers. template struct int_checker { template static bool fits_in_int(T value) { unsigned max = std::numeric_limits::max(); return value <= max; } static bool fits_in_int(bool) { return true; } }; template <> struct int_checker { template static bool fits_in_int(T value) { return value >= std::numeric_limits::min() && value <= std::numeric_limits::max(); } static bool fits_in_int(int) { return true; } }; class printf_precision_handler: public function { public: template typename std::enable_if::value, int>::type operator()(T value) { if (!int_checker::is_signed>::fits_in_int(value)) FMT_THROW(format_error("number is too big")); return static_cast(value); } template typename std::enable_if::value, int>::type operator()(T) { FMT_THROW(format_error("precision is not integer")); return 0; } }; // An argument visitor that returns true iff arg is a zero integer. class is_zero_int: public function { public: template typename std::enable_if::value, bool>::type operator()(T value) { return value == 0; } template typename std::enable_if::value, bool>::type operator()(T) { return false; } }; template struct make_unsigned_or_bool : std::make_unsigned {}; template <> struct make_unsigned_or_bool { typedef bool type; }; template class arg_converter: public function { private: typedef typename Context::char_type Char; basic_format_arg &arg_; typename Context::char_type type_; public: arg_converter(basic_format_arg &arg, Char type) : arg_(arg), type_(type) {} void operator()(bool value) { if (type_ != 's') operator()(value); } template typename std::enable_if::value>::type operator()(U value) { bool is_signed = type_ == 'd' || type_ == 'i'; typedef typename std::conditional< std::is_same::value, U, T>::type TargetType; if (const_check(sizeof(TargetType) <= sizeof(int))) { // Extra casts are used to silence warnings. if (is_signed) { arg_ = internal::make_arg( static_cast(static_cast(value))); } else { typedef typename make_unsigned_or_bool::type Unsigned; arg_ = internal::make_arg( static_cast(static_cast(value))); } } else { if (is_signed) { // glibc's printf doesn't sign extend arguments of smaller types: // std::printf("%lld", -42); // prints "4294967254" // but we don't have to do the same because it's a UB. arg_ = internal::make_arg(static_cast(value)); } else { arg_ = internal::make_arg( static_cast::type>(value)); } } } template typename std::enable_if::value>::type operator()(U) { // No coversion needed for non-integral types. } }; // Converts an integer argument to T for printf, if T is an integral type. // If T is void, the argument is converted to corresponding signed or unsigned // type depending on the type specifier: 'd' and 'i' - signed, other - // unsigned). template void convert_arg(basic_format_arg &arg, Char type) { visit_format_arg(arg_converter(arg, type), arg); } // Converts an integer argument to char for printf. template class char_converter: public function { private: basic_format_arg &arg_; public: explicit char_converter(basic_format_arg &arg) : arg_(arg) {} template typename std::enable_if::value>::type operator()(T value) { typedef typename Context::char_type Char; arg_ = internal::make_arg(static_cast(value)); } template typename std::enable_if::value>::type operator()(T) { // No coversion needed for non-integral types. } }; // Checks if an argument is a valid printf width specifier and sets // left alignment if it is negative. template class printf_width_handler: public function { private: typedef basic_format_specs format_specs; format_specs &spec_; public: explicit printf_width_handler(format_specs &spec) : spec_(spec) {} template typename std::enable_if::value, unsigned>::type operator()(T value) { typedef typename internal::int_traits::main_type UnsignedType; UnsignedType width = static_cast(value); if (internal::is_negative(value)) { spec_.align_ = ALIGN_LEFT; width = 0 - width; } unsigned int_max = std::numeric_limits::max(); if (width > int_max) FMT_THROW(format_error("number is too big")); return static_cast(width); } template typename std::enable_if::value, unsigned>::type operator()(T) { FMT_THROW(format_error("width is not integer")); return 0; } }; template void printf(basic_buffer &buf, basic_string_view format, basic_format_args args) { Context(std::back_inserter(buf), format, args).format(); } } // namespace internal using internal::printf; // For printing into memory_buffer. template class printf_arg_formatter; template < typename OutputIt, typename Char, typename ArgFormatter = printf_arg_formatter>>> class basic_printf_context; /** \rst The ``printf`` argument formatter. \endrst */ template class printf_arg_formatter: public internal::function< typename internal::arg_formatter_base::iterator>, public internal::arg_formatter_base { private: typedef typename Range::value_type char_type; typedef decltype(internal::declval().begin()) iterator; typedef internal::arg_formatter_base base; typedef basic_printf_context context_type; context_type &context_; void write_null_pointer(char) { this->spec()->type = 0; this->write("(nil)"); } void write_null_pointer(wchar_t) { this->spec()->type = 0; this->write(L"(nil)"); } public: typedef typename base::format_specs format_specs; /** \rst Constructs an argument formatter object. *buffer* is a reference to the output buffer and *spec* contains format specifier information for standard argument types. \endrst */ printf_arg_formatter(internal::basic_buffer &buffer, format_specs &spec, context_type &ctx) : base(back_insert_range>(buffer), &spec, ctx.locale()), context_(ctx) {} template typename std::enable_if::value, iterator>::type operator()(T value) { // MSVC2013 fails to compile separate overloads for bool and char_type so // use std::is_same instead. if (std::is_same::value) { format_specs &fmt_spec = *this->spec(); if (fmt_spec.type != 's') return base::operator()(value ? 1 : 0); fmt_spec.type = 0; this->write(value != 0); } else if (std::is_same::value) { format_specs &fmt_spec = *this->spec(); if (fmt_spec.type && fmt_spec.type != 'c') return (*this)(static_cast(value)); fmt_spec.flags = 0; fmt_spec.align_ = ALIGN_RIGHT; return base::operator()(value); } else { return base::operator()(value); } return this->out(); } template typename std::enable_if::value, iterator>::type operator()(T value) { return base::operator()(value); } /** Formats a null-terminated C string. */ iterator operator()(const char *value) { if (value) base::operator()(value); else if (this->spec()->type == 'p') write_null_pointer(char_type()); else this->write("(null)"); return this->out(); } /** Formats a null-terminated wide C string. */ iterator operator()(const wchar_t *value) { if (value) base::operator()(value); else if (this->spec()->type == 'p') write_null_pointer(char_type()); else this->write(L"(null)"); return this->out(); } iterator operator()(basic_string_view value) { return base::operator()(value); } iterator operator()(monostate value) { return base::operator()(value); } /** Formats a pointer. */ iterator operator()(const void *value) { if (value) return base::operator()(value); this->spec()->type = 0; write_null_pointer(char_type()); return this->out(); } /** Formats an argument of a custom (user-defined) type. */ iterator operator()(typename basic_format_arg::handle handle) { handle.format(context_); return this->out(); } }; template struct printf_formatter { template auto parse(ParseContext &ctx) -> decltype(ctx.begin()) { return ctx.begin(); } template auto format(const T &value, FormatContext &ctx) -> decltype(ctx.out()) { internal::format_value(internal::get_container(ctx.out()), value); return ctx.out(); } }; /** This template formats data and writes the output to a writer. */ template class basic_printf_context : // Inherit publicly as a workaround for the icc bug // https://software.intel.com/en-us/forums/intel-c-compiler/topic/783476. public internal::context_base< OutputIt, basic_printf_context, Char> { public: /** The character type for the output. */ typedef Char char_type; template struct formatter_type { typedef printf_formatter type; }; private: typedef internal::context_base base; typedef typename base::format_arg format_arg; typedef basic_format_specs format_specs; typedef internal::null_terminating_iterator iterator; void parse_flags(format_specs &spec, iterator &it); // Returns the argument with specified index or, if arg_index is equal // to the maximum unsigned value, the next argument. format_arg get_arg( iterator it, unsigned arg_index = (std::numeric_limits::max)()); // Parses argument index, flags and width and returns the argument index. unsigned parse_header(iterator &it, format_specs &spec); public: /** \rst Constructs a ``printf_context`` object. References to the arguments and the writer are stored in the context object so make sure they have appropriate lifetimes. \endrst */ basic_printf_context(OutputIt out, basic_string_view format_str, basic_format_args args) : base(out, format_str, args) {} using base::parse_context; using base::out; using base::advance_to; /** Formats stored arguments and writes the output to the range. */ void format(); }; template void basic_printf_context::parse_flags( format_specs &spec, iterator &it) { for (;;) { switch (*it++) { case '-': spec.align_ = ALIGN_LEFT; break; case '+': spec.flags |= SIGN_FLAG | PLUS_FLAG; break; case '0': spec.fill_ = '0'; break; case ' ': spec.flags |= SIGN_FLAG; break; case '#': spec.flags |= HASH_FLAG; break; default: --it; return; } } } template typename basic_printf_context::format_arg basic_printf_context::get_arg( iterator it, unsigned arg_index) { (void)it; if (arg_index == std::numeric_limits::max()) return this->do_get_arg(this->parse_context().next_arg_id()); return base::get_arg(arg_index - 1); } template unsigned basic_printf_context::parse_header( iterator &it, format_specs &spec) { unsigned arg_index = std::numeric_limits::max(); char_type c = *it; if (c >= '0' && c <= '9') { // Parse an argument index (if followed by '$') or a width possibly // preceded with '0' flag(s). internal::error_handler eh; unsigned value = parse_nonnegative_int(it, eh); if (*it == '$') { // value is an argument index ++it; arg_index = value; } else { if (c == '0') spec.fill_ = '0'; if (value != 0) { // Nonzero value means that we parsed width and don't need to // parse it or flags again, so return now. spec.width_ = value; return arg_index; } } } parse_flags(spec, it); // Parse width. if (*it >= '0' && *it <= '9') { internal::error_handler eh; spec.width_ = parse_nonnegative_int(it, eh); } else if (*it == '*') { ++it; spec.width_ = visit_format_arg( internal::printf_width_handler(spec), get_arg(it)); } return arg_index; } template void basic_printf_context::format() { auto &buffer = internal::get_container(this->out()); auto start = iterator(this->parse_context()); auto it = start; using internal::pointer_from; while (*it) { char_type c = *it++; if (c != '%') continue; if (*it == c) { buffer.append(pointer_from(start), pointer_from(it)); start = ++it; continue; } buffer.append(pointer_from(start), pointer_from(it) - 1); format_specs spec; spec.align_ = ALIGN_RIGHT; // Parse argument index, flags and width. unsigned arg_index = parse_header(it, spec); // Parse precision. if (*it == '.') { ++it; if ('0' <= *it && *it <= '9') { internal::error_handler eh; spec.precision = static_cast(parse_nonnegative_int(it, eh)); } else if (*it == '*') { ++it; spec.precision = visit_format_arg(internal::printf_precision_handler(), get_arg(it)); } else { spec.precision = 0; } } format_arg arg = get_arg(it, arg_index); if (spec.has(HASH_FLAG) && visit_format_arg(internal::is_zero_int(), arg)) spec.flags = static_cast(spec.flags & (~internal::to_unsigned(HASH_FLAG))); if (spec.fill_ == '0') { if (arg.is_arithmetic()) spec.align_ = ALIGN_NUMERIC; else spec.fill_ = ' '; // Ignore '0' flag for non-numeric types. } // Parse length and convert the argument to the required type. using internal::convert_arg; switch (*it++) { case 'h': if (*it == 'h') convert_arg(arg, *++it); else convert_arg(arg, *it); break; case 'l': if (*it == 'l') convert_arg(arg, *++it); else convert_arg(arg, *it); break; case 'j': convert_arg(arg, *it); break; case 'z': convert_arg(arg, *it); break; case 't': convert_arg(arg, *it); break; case 'L': // printf produces garbage when 'L' is omitted for long double, no // need to do the same. break; default: --it; convert_arg(arg, *it); } // Parse type. if (!*it) FMT_THROW(format_error("invalid format string")); spec.type = static_cast(*it++); if (arg.is_integral()) { // Normalize type. switch (spec.type) { case 'i': case 'u': spec.type = 'd'; break; case 'c': // TODO: handle wchar_t better? visit_format_arg( internal::char_converter(arg), arg); break; } } start = it; // Format argument. visit_format_arg(AF(buffer, spec, *this), arg); } buffer.append(pointer_from(start), pointer_from(it)); } template struct basic_printf_context_t { typedef basic_printf_context< std::back_insert_iterator, typename Buffer::value_type> type; }; typedef basic_printf_context_t::type printf_context; typedef basic_printf_context_t::type wprintf_context; typedef basic_format_args printf_args; typedef basic_format_args wprintf_args; /** \rst Constructs an `~fmt::format_arg_store` object that contains references to arguments and can be implicitly converted to `~fmt::printf_args`. \endrst */ template inline format_arg_store make_printf_args(const Args &... args) { return {args...}; } /** \rst Constructs an `~fmt::format_arg_store` object that contains references to arguments and can be implicitly converted to `~fmt::wprintf_args`. \endrst */ template inline format_arg_store make_wprintf_args(const Args &... args) { return {args...}; } template inline std::basic_string vsprintf(const S &format, basic_format_args>::type> args) { basic_memory_buffer buffer; printf(buffer, to_string_view(format), args); return to_string(buffer); } /** \rst Formats arguments and returns the result as a string. **Example**:: std::string message = fmt::sprintf("The answer is %d", 42); \endrst */ template inline FMT_ENABLE_IF_T( internal::is_string::value, std::basic_string) sprintf(const S &format, const Args & ... args) { internal::check_format_string(format); typedef internal::basic_buffer buffer; typedef typename basic_printf_context_t::type context; format_arg_store as{ args... }; return vsprintf(to_string_view(format), basic_format_args(as)); } template inline int vfprintf(std::FILE *f, const S &format, basic_format_args>::type> args) { basic_memory_buffer buffer; printf(buffer, to_string_view(format), args); std::size_t size = buffer.size(); return std::fwrite( buffer.data(), sizeof(Char), size, f) < size ? -1 : static_cast(size); } /** \rst Prints formatted data to the file *f*. **Example**:: fmt::fprintf(stderr, "Don't %s!", "panic"); \endrst */ template inline FMT_ENABLE_IF_T(internal::is_string::value, int) fprintf(std::FILE *f, const S &format, const Args & ... args) { internal::check_format_string(format); typedef internal::basic_buffer buffer; typedef typename basic_printf_context_t::type context; format_arg_store as{ args... }; return vfprintf(f, to_string_view(format), basic_format_args(as)); } template inline int vprintf(const S &format, basic_format_args>::type> args) { return vfprintf(stdout, to_string_view(format), args); } /** \rst Prints formatted data to ``stdout``. **Example**:: fmt::printf("Elapsed time: %.2f seconds", 1.23); \endrst */ template inline FMT_ENABLE_IF_T(internal::is_string::value, int) printf(const S &format_str, const Args & ... args) { internal::check_format_string(format_str); typedef internal::basic_buffer buffer; typedef typename basic_printf_context_t::type context; format_arg_store as{ args... }; return vprintf(to_string_view(format_str), basic_format_args(as)); } template inline int vfprintf(std::basic_ostream &os, const S &format, basic_format_args>::type> args) { basic_memory_buffer buffer; printf(buffer, to_string_view(format), args); internal::write(os, buffer); return static_cast(buffer.size()); } /** \rst Prints formatted data to the stream *os*. **Example**:: fmt::fprintf(cerr, "Don't %s!", "panic"); \endrst */ template inline FMT_ENABLE_IF_T(internal::is_string::value, int) fprintf(std::basic_ostream &os, const S &format_str, const Args & ... args) { internal::check_format_string(format_str); typedef internal::basic_buffer buffer; typedef typename basic_printf_context_t::type context; format_arg_store as{ args... }; return vfprintf(os, to_string_view(format_str), basic_format_args(as)); } FMT_END_NAMESPACE #endif // FMT_PRINTF_H_