ladybird/AK/Format.h
Tom f021baf255 AK: Add Formatter<FixedPoint<...>> without floating point
Rather than casting the FixedPoint to double, format the FixedPoint
directly. This avoids using floating point instruction, which in
turn enables this to be used even in the kernel.
2022-01-23 22:45:21 +00:00

720 lines
21 KiB
C++

/*
* Copyright (c) 2020, the SerenityOS developers.
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/CheckedFormatString.h>
#include <AK/AllOf.h>
#include <AK/AnyOf.h>
#include <AK/Array.h>
#include <AK/Error.h>
#include <AK/FixedPoint.h>
#include <AK/Forward.h>
#include <AK/Optional.h>
#include <AK/StringView.h>
#ifndef KERNEL
# include <stdio.h>
# include <string.h>
#endif
namespace AK {
class TypeErasedFormatParams;
class FormatParser;
class FormatBuilder;
template<typename T, typename = void>
struct Formatter {
using __no_formatter_defined = void;
};
template<typename T, typename = void>
inline constexpr bool HasFormatter = true;
template<typename T>
inline constexpr bool HasFormatter<T, typename Formatter<T>::__no_formatter_defined> = false;
constexpr size_t max_format_arguments = 256;
struct TypeErasedParameter {
enum class Type {
UInt8,
UInt16,
UInt32,
UInt64,
Int8,
Int16,
Int32,
Int64,
Custom
};
template<size_t size, bool is_unsigned>
static consteval Type get_type_from_size()
{
if constexpr (is_unsigned) {
if constexpr (size == 1)
return Type::UInt8;
if constexpr (size == 2)
return Type::UInt16;
if constexpr (size == 4)
return Type::UInt32;
if constexpr (size == 8)
return Type::UInt64;
} else {
if constexpr (size == 1)
return Type::Int8;
if constexpr (size == 2)
return Type::Int16;
if constexpr (size == 4)
return Type::Int32;
if constexpr (size == 8)
return Type::Int64;
}
VERIFY_NOT_REACHED();
}
template<typename T>
static consteval Type get_type()
{
if constexpr (IsIntegral<T>)
return get_type_from_size<sizeof(T), IsUnsigned<T>>();
else
return Type::Custom;
}
template<typename Visitor>
constexpr auto visit(Visitor&& visitor) const
{
switch (type) {
case TypeErasedParameter::Type::UInt8:
return visitor(*static_cast<const u8*>(value));
case TypeErasedParameter::Type::UInt16:
return visitor(*static_cast<const u16*>(value));
case TypeErasedParameter::Type::UInt32:
return visitor(*static_cast<const u32*>(value));
case TypeErasedParameter::Type::UInt64:
return visitor(*static_cast<const u64*>(value));
case TypeErasedParameter::Type::Int8:
return visitor(*static_cast<const i8*>(value));
case TypeErasedParameter::Type::Int16:
return visitor(*static_cast<const i16*>(value));
case TypeErasedParameter::Type::Int32:
return visitor(*static_cast<const i32*>(value));
case TypeErasedParameter::Type::Int64:
return visitor(*static_cast<const i64*>(value));
default:
TODO();
}
}
constexpr size_t to_size() const
{
return visit([]<typename T>(T value) {
if constexpr (sizeof(T) > sizeof(size_t))
VERIFY(value < NumericLimits<size_t>::max());
if constexpr (IsSigned<T>)
VERIFY(value > 0);
return static_cast<size_t>(value);
});
}
// FIXME: Getters and setters.
const void* value;
Type type;
ErrorOr<void> (*formatter)(TypeErasedFormatParams&, FormatBuilder&, FormatParser&, void const* value);
};
class FormatBuilder {
public:
enum class Align {
Default,
Left,
Center,
Right,
};
enum class SignMode {
OnlyIfNeeded,
Always,
Reserved,
Default = OnlyIfNeeded,
};
explicit FormatBuilder(StringBuilder& builder)
: m_builder(builder)
{
}
ErrorOr<void> put_padding(char fill, size_t amount);
ErrorOr<void> put_literal(StringView value);
ErrorOr<void> put_string(
StringView value,
Align align = Align::Left,
size_t min_width = 0,
size_t max_width = NumericLimits<size_t>::max(),
char fill = ' ');
ErrorOr<void> put_u64(
u64 value,
u8 base = 10,
bool prefix = false,
bool upper_case = false,
bool zero_pad = false,
Align align = Align::Right,
size_t min_width = 0,
char fill = ' ',
SignMode sign_mode = SignMode::OnlyIfNeeded,
bool is_negative = false);
ErrorOr<void> put_i64(
i64 value,
u8 base = 10,
bool prefix = false,
bool upper_case = false,
bool zero_pad = false,
Align align = Align::Right,
size_t min_width = 0,
char fill = ' ',
SignMode sign_mode = SignMode::OnlyIfNeeded);
ErrorOr<void> put_fixed_point(
i64 integer_value,
u64 fraction_value,
u64 fraction_one,
u8 base = 10,
bool upper_case = false,
bool zero_pad = false,
Align align = Align::Right,
size_t min_width = 0,
size_t precision = 6,
char fill = ' ',
SignMode sign_mode = SignMode::OnlyIfNeeded);
#ifndef KERNEL
ErrorOr<void> put_f80(
long double value,
u8 base = 10,
bool upper_case = false,
Align align = Align::Right,
size_t min_width = 0,
size_t precision = 6,
char fill = ' ',
SignMode sign_mode = SignMode::OnlyIfNeeded);
ErrorOr<void> put_f64(
double value,
u8 base = 10,
bool upper_case = false,
bool zero_pad = false,
Align align = Align::Right,
size_t min_width = 0,
size_t precision = 6,
char fill = ' ',
SignMode sign_mode = SignMode::OnlyIfNeeded);
#endif
ErrorOr<void> put_hexdump(
ReadonlyBytes,
size_t width,
char fill = ' ');
const StringBuilder& builder() const
{
return m_builder;
}
StringBuilder& builder() { return m_builder; }
private:
StringBuilder& m_builder;
};
class TypeErasedFormatParams {
public:
Span<const TypeErasedParameter> parameters() const { return m_parameters; }
void set_parameters(Span<const TypeErasedParameter> parameters) { m_parameters = parameters; }
size_t take_next_index() { return m_next_index++; }
private:
Span<const TypeErasedParameter> m_parameters;
size_t m_next_index { 0 };
};
template<typename T>
ErrorOr<void> __format_value(TypeErasedFormatParams& params, FormatBuilder& builder, FormatParser& parser, const void* value)
{
Formatter<T> formatter;
formatter.parse(params, parser);
return formatter.format(builder, *static_cast<const T*>(value));
}
template<typename... Parameters>
class VariadicFormatParams : public TypeErasedFormatParams {
public:
static_assert(sizeof...(Parameters) <= max_format_arguments);
explicit VariadicFormatParams(const Parameters&... parameters)
: m_data({ TypeErasedParameter { &parameters, TypeErasedParameter::get_type<Parameters>(), __format_value<Parameters> }... })
{
this->set_parameters(m_data);
}
private:
Array<TypeErasedParameter, sizeof...(Parameters)> m_data;
};
// We use the same format for most types for consistency. This is taken directly from
// std::format. One difference is that we are not counting the width or sign towards the
// total width when calculating zero padding for numbers.
// https://en.cppreference.com/w/cpp/utility/format/formatter#Standard_format_specification
struct StandardFormatter {
enum class Mode {
Default,
Binary,
BinaryUppercase,
Decimal,
Octal,
Hexadecimal,
HexadecimalUppercase,
Character,
String,
Pointer,
Float,
Hexfloat,
HexfloatUppercase,
HexDump,
};
FormatBuilder::Align m_align = FormatBuilder::Align::Default;
FormatBuilder::SignMode m_sign_mode = FormatBuilder::SignMode::OnlyIfNeeded;
Mode m_mode = Mode::Default;
bool m_alternative_form = false;
char m_fill = ' ';
bool m_zero_pad = false;
Optional<size_t> m_width;
Optional<size_t> m_precision;
void parse(TypeErasedFormatParams&, FormatParser&);
};
template<typename T>
struct Formatter<T, typename EnableIf<IsIntegral<T>>::Type> : StandardFormatter {
Formatter() = default;
explicit Formatter(StandardFormatter formatter)
: StandardFormatter(move(formatter))
{
}
ErrorOr<void> format(FormatBuilder&, T);
};
template<>
struct Formatter<StringView> : StandardFormatter {
Formatter() = default;
explicit Formatter(StandardFormatter formatter)
: StandardFormatter(move(formatter))
{
}
ErrorOr<void> format(FormatBuilder&, StringView);
};
template<typename T>
requires(HasFormatter<T>) struct Formatter<Vector<T>> : StandardFormatter {
Formatter() = default;
explicit Formatter(StandardFormatter formatter)
: StandardFormatter(move(formatter))
{
}
ErrorOr<void> format(FormatBuilder& builder, Vector<T> value)
{
if (m_mode == Mode::Pointer) {
Formatter<FlatPtr> formatter { *this };
TRY(formatter.format(builder, reinterpret_cast<FlatPtr>(value.data())));
return {};
}
if (m_sign_mode != FormatBuilder::SignMode::Default)
VERIFY_NOT_REACHED();
if (m_alternative_form)
VERIFY_NOT_REACHED();
if (m_zero_pad)
VERIFY_NOT_REACHED();
if (m_mode != Mode::Default)
VERIFY_NOT_REACHED();
if (m_width.has_value() && m_precision.has_value())
VERIFY_NOT_REACHED();
m_width = m_width.value_or(0);
m_precision = m_precision.value_or(NumericLimits<size_t>::max());
Formatter<T> content_fmt;
TRY(builder.put_literal("[ "sv));
bool first = true;
for (auto& content : value) {
if (!first) {
TRY(builder.put_literal(", "sv));
content_fmt = Formatter<T> {};
}
first = false;
TRY(content_fmt.format(builder, content));
}
TRY(builder.put_literal(" ]"sv));
return {};
}
};
template<>
struct Formatter<ReadonlyBytes> : Formatter<StringView> {
ErrorOr<void> format(FormatBuilder& builder, ReadonlyBytes value)
{
if (m_mode == Mode::Pointer) {
Formatter<FlatPtr> formatter { *this };
return formatter.format(builder, reinterpret_cast<FlatPtr>(value.data()));
}
if (m_mode == Mode::Default || m_mode == Mode::HexDump) {
m_mode = Mode::HexDump;
return Formatter<StringView>::format(builder, value);
}
return Formatter<StringView>::format(builder, value);
}
};
template<>
struct Formatter<Bytes> : Formatter<ReadonlyBytes> {
};
template<>
struct Formatter<const char*> : Formatter<StringView> {
ErrorOr<void> format(FormatBuilder& builder, const char* value)
{
if (m_mode == Mode::Pointer) {
Formatter<FlatPtr> formatter { *this };
return formatter.format(builder, reinterpret_cast<FlatPtr>(value));
}
return Formatter<StringView>::format(builder, value);
}
};
template<>
struct Formatter<char*> : Formatter<const char*> {
};
template<size_t Size>
struct Formatter<char[Size]> : Formatter<const char*> {
};
template<size_t Size>
struct Formatter<unsigned char[Size]> : Formatter<StringView> {
ErrorOr<void> format(FormatBuilder& builder, const unsigned char* value)
{
if (m_mode == Mode::Pointer) {
Formatter<FlatPtr> formatter { *this };
return formatter.format(builder, reinterpret_cast<FlatPtr>(value));
}
return Formatter<StringView>::format(builder, { value, Size });
}
};
template<>
struct Formatter<String> : Formatter<StringView> {
};
template<>
struct Formatter<FlyString> : Formatter<StringView> {
};
template<typename T>
struct Formatter<T*> : StandardFormatter {
ErrorOr<void> format(FormatBuilder& builder, T* value)
{
if (m_mode == Mode::Default)
m_mode = Mode::Pointer;
Formatter<FlatPtr> formatter { *this };
return formatter.format(builder, reinterpret_cast<FlatPtr>(value));
}
};
template<>
struct Formatter<char> : StandardFormatter {
ErrorOr<void> format(FormatBuilder&, char);
};
template<>
struct Formatter<wchar_t> : StandardFormatter {
ErrorOr<void> format(FormatBuilder& builder, wchar_t);
};
template<>
struct Formatter<bool> : StandardFormatter {
ErrorOr<void> format(FormatBuilder&, bool);
};
#ifndef KERNEL
template<>
struct Formatter<float> : StandardFormatter {
ErrorOr<void> format(FormatBuilder&, float value);
};
template<>
struct Formatter<double> : StandardFormatter {
Formatter() = default;
explicit Formatter(StandardFormatter formatter)
: StandardFormatter(formatter)
{
}
ErrorOr<void> format(FormatBuilder&, double);
};
template<>
struct Formatter<long double> : StandardFormatter {
Formatter() = default;
explicit Formatter(StandardFormatter formatter)
: StandardFormatter(formatter)
{
}
ErrorOr<void> format(FormatBuilder&, long double value);
};
#endif
template<size_t precision, typename Underlying>
struct Formatter<FixedPoint<precision, Underlying>> : StandardFormatter {
Formatter() = default;
explicit Formatter(StandardFormatter formatter)
: StandardFormatter(formatter)
{
}
ErrorOr<void> format(FormatBuilder& builder, FixedPoint<precision, Underlying> value)
{
u8 base;
bool upper_case;
if (m_mode == Mode::Default || m_mode == Mode::Float) {
base = 10;
upper_case = false;
} else if (m_mode == Mode::Hexfloat) {
base = 16;
upper_case = false;
} else if (m_mode == Mode::HexfloatUppercase) {
base = 16;
upper_case = true;
} else {
VERIFY_NOT_REACHED();
}
m_width = m_width.value_or(0);
m_precision = m_precision.value_or(6);
i64 integer = value.ltrunk();
constexpr u64 one = static_cast<Underlying>(1) << precision;
u64 fraction_raw = value.raw() & (one - 1);
return builder.put_fixed_point(integer, fraction_raw, one, base, upper_case, m_zero_pad, m_align, m_width.value(), m_precision.value(), m_fill, m_sign_mode);
}
};
template<>
struct Formatter<std::nullptr_t> : Formatter<FlatPtr> {
ErrorOr<void> format(FormatBuilder& builder, std::nullptr_t)
{
if (m_mode == Mode::Default)
m_mode = Mode::Pointer;
return Formatter<FlatPtr>::format(builder, 0);
}
};
ErrorOr<void> vformat(StringBuilder&, StringView fmtstr, TypeErasedFormatParams&);
#ifndef KERNEL
void vout(FILE*, StringView fmtstr, TypeErasedFormatParams&, bool newline = false);
template<typename... Parameters>
void out(FILE* file, CheckedFormatString<Parameters...>&& fmtstr, const Parameters&... parameters)
{
VariadicFormatParams variadic_format_params { parameters... };
vout(file, fmtstr.view(), variadic_format_params);
}
template<typename... Parameters>
void outln(FILE* file, CheckedFormatString<Parameters...>&& fmtstr, const Parameters&... parameters)
{
VariadicFormatParams variadic_format_params { parameters... };
vout(file, fmtstr.view(), variadic_format_params, true);
}
inline void outln(FILE* file) { fputc('\n', file); }
template<typename... Parameters>
void out(CheckedFormatString<Parameters...>&& fmtstr, const Parameters&... parameters) { out(stdout, move(fmtstr), parameters...); }
template<typename... Parameters>
void outln(CheckedFormatString<Parameters...>&& fmtstr, const Parameters&... parameters) { outln(stdout, move(fmtstr), parameters...); }
inline void outln() { outln(stdout); }
# define outln_if(flag, fmt, ...) \
do { \
if constexpr (flag) \
outln(fmt, ##__VA_ARGS__); \
} while (0)
template<typename... Parameters>
void warn(CheckedFormatString<Parameters...>&& fmtstr, const Parameters&... parameters)
{
out(stderr, move(fmtstr), parameters...);
}
template<typename... Parameters>
void warnln(CheckedFormatString<Parameters...>&& fmtstr, const Parameters&... parameters) { outln(stderr, move(fmtstr), parameters...); }
inline void warnln() { outln(stderr); }
# define warnln_if(flag, fmt, ...) \
do { \
if constexpr (flag) \
outln(fmt, ##__VA_ARGS__); \
} while (0)
#endif
void vdbgln(StringView fmtstr, TypeErasedFormatParams&);
template<typename... Parameters>
void dbgln(CheckedFormatString<Parameters...>&& fmtstr, const Parameters&... parameters)
{
VariadicFormatParams variadic_format_params { parameters... };
vdbgln(fmtstr.view(), variadic_format_params);
}
inline void dbgln() { dbgln(""); }
void set_debug_enabled(bool);
#ifdef KERNEL
void vdmesgln(StringView fmtstr, TypeErasedFormatParams&);
template<typename... Parameters>
void dmesgln(CheckedFormatString<Parameters...>&& fmt, const Parameters&... parameters)
{
VariadicFormatParams variadic_format_params { parameters... };
vdmesgln(fmt.view(), variadic_format_params);
}
void v_critical_dmesgln(StringView fmtstr, TypeErasedFormatParams&);
// be very careful to not cause any allocations here, since we could be in
// a very unstable situation
template<typename... Parameters>
void critical_dmesgln(CheckedFormatString<Parameters...>&& fmt, const Parameters&... parameters)
{
VariadicFormatParams variadic_format_params { parameters... };
v_critical_dmesgln(fmt.view(), variadic_format_params);
}
#endif
template<typename T>
class FormatIfSupported {
public:
explicit FormatIfSupported(const T& value)
: m_value(value)
{
}
const T& value() const { return m_value; }
private:
const T& m_value;
};
template<typename T, bool Supported = false>
struct __FormatIfSupported : Formatter<StringView> {
ErrorOr<void> format(FormatBuilder& builder, FormatIfSupported<T> const&)
{
return Formatter<StringView>::format(builder, "?");
}
};
template<typename T>
struct __FormatIfSupported<T, true> : Formatter<T> {
ErrorOr<void> format(FormatBuilder& builder, FormatIfSupported<T> const& value)
{
return Formatter<T>::format(builder, value.value());
}
};
template<typename T>
struct Formatter<FormatIfSupported<T>> : __FormatIfSupported<T, HasFormatter<T>> {
};
// This is a helper class, the idea is that if you want to implement a formatter you can inherit
// from this class to "break down" the formatting.
struct FormatString {
};
template<>
struct Formatter<FormatString> : Formatter<StringView> {
template<typename... Parameters>
ErrorOr<void> format(FormatBuilder& builder, StringView fmtstr, const Parameters&... parameters)
{
VariadicFormatParams variadic_format_params { parameters... };
return vformat(builder, fmtstr, variadic_format_params);
}
ErrorOr<void> vformat(FormatBuilder& builder, StringView fmtstr, TypeErasedFormatParams& params);
};
template<>
struct Formatter<Error> : Formatter<FormatString> {
ErrorOr<void> format(FormatBuilder& builder, Error const& error)
{
#if defined(__serenity__) && defined(KERNEL)
if (error.is_errno())
return Formatter<FormatString>::format(builder, "Error(errno={})", error.code());
return Formatter<FormatString>::format(builder, "Error({})", error.string_literal());
#else
if (error.is_syscall())
return Formatter<FormatString>::format(builder, "{}: {} (errno={})", error.string_literal(), strerror(error.code()), error.code());
if (error.is_errno())
return Formatter<FormatString>::format(builder, "{} (errno={})", strerror(error.code()), error.code());
return Formatter<FormatString>::format(builder, "{}", error.string_literal());
#endif
}
};
template<typename T, typename ErrorType>
struct Formatter<ErrorOr<T, ErrorType>> : Formatter<FormatString> {
ErrorOr<void> format(FormatBuilder& builder, ErrorOr<T, ErrorType> const& error_or)
{
if (error_or.is_error())
return Formatter<FormatString>::format(builder, "{}", error_or.error());
return Formatter<FormatString>::format(builder, "{{{}}}", error_or.value());
}
};
} // namespace AK
#ifdef KERNEL
using AK::critical_dmesgln;
using AK::dmesgln;
#else
using AK::out;
using AK::outln;
using AK::warn;
using AK::warnln;
#endif
using AK::dbgln;
using AK::CheckedFormatString;
using AK::FormatIfSupported;
using AK::FormatString;
#define dbgln_if(flag, fmt, ...) \
do { \
if constexpr (flag) \
dbgln(fmt, ##__VA_ARGS__); \
} while (0)