ladybird/AK/Format.h
kleines Filmröllchen 1e1fa4eac4 AK: Add Formatter for Vector
For debugging purposes, it is very useful to look at a Vector in a
simple list representation. Therefore, the new Formatter for Vector
provides a string representation of the following form:

```
[ 1, 2, 3, 4, 5 ]
```

This requires the content type of Vector to be formattable with default
arguments.

The current implementation ignores width and precision, which may be
accounted for later or passed down to the content formatter.
2021-07-13 17:40:07 +02:00

629 lines
17 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/GenericLexer.h>
#include <AK/Optional.h>
#include <AK/StringView.h>
#ifndef KERNEL
# include <stdio.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;
}
constexpr size_t to_size() const
{
i64 svalue;
if (type == TypeErasedParameter::Type::UInt8)
svalue = *static_cast<const u8*>(value);
else if (type == TypeErasedParameter::Type::UInt16)
svalue = *static_cast<const u16*>(value);
else if (type == TypeErasedParameter::Type::UInt32)
svalue = *static_cast<const u32*>(value);
else if (type == TypeErasedParameter::Type::UInt64)
svalue = *static_cast<const u64*>(value);
else if (type == TypeErasedParameter::Type::Int8)
svalue = *static_cast<const i8*>(value);
else if (type == TypeErasedParameter::Type::Int16)
svalue = *static_cast<const i16*>(value);
else if (type == TypeErasedParameter::Type::Int32)
svalue = *static_cast<const i32*>(value);
else if (type == TypeErasedParameter::Type::Int64)
svalue = *static_cast<const i64*>(value);
else
VERIFY_NOT_REACHED();
VERIFY(svalue >= 0);
return static_cast<size_t>(svalue);
}
// FIXME: Getters and setters.
const void* value;
Type type;
void (*formatter)(TypeErasedFormatParams&, FormatBuilder&, FormatParser&, const void* value);
};
class FormatParser : public GenericLexer {
public:
struct FormatSpecifier {
StringView flags;
size_t index;
};
explicit FormatParser(StringView input);
StringView consume_literal();
bool consume_number(size_t& value);
bool consume_specifier(FormatSpecifier& specifier);
bool consume_replacement_field(size_t& index);
};
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)
{
}
void put_padding(char fill, size_t amount);
void put_literal(StringView value);
void put_string(
StringView value,
Align align = Align::Left,
size_t min_width = 0,
size_t max_width = NumericLimits<size_t>::max(),
char fill = ' ');
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);
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);
#ifndef KERNEL
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);
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
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>
void __format_value(TypeErasedFormatParams& params, FormatBuilder& builder, FormatParser& parser, const void* value)
{
Formatter<T> formatter;
formatter.parse(params, parser);
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(formatter)
{
}
void format(FormatBuilder&, T value);
};
template<>
struct Formatter<StringView> : StandardFormatter {
Formatter() = default;
explicit Formatter(StandardFormatter formatter)
: StandardFormatter(formatter)
{
}
void format(FormatBuilder&, StringView value);
};
template<typename T>
requires(HasFormatter<T>) struct Formatter<Vector<T>> : StandardFormatter {
Formatter() = default;
explicit Formatter(StandardFormatter formatter)
: StandardFormatter(formatter)
{
}
void format(FormatBuilder& builder, Vector<T> value)
{
if (m_mode == Mode::Pointer) {
Formatter<FlatPtr> formatter { *this };
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;
builder.put_literal("[ ");
bool first = true;
for (auto& content : value) {
if (!first)
builder.put_literal(", ");
first = false;
content_fmt.format(builder, content);
}
builder.put_literal(" ]");
}
};
template<>
struct Formatter<ReadonlyBytes> : Formatter<StringView> {
void format(FormatBuilder& builder, ReadonlyBytes const& value)
{
if (m_mode == Mode::Pointer) {
Formatter<FlatPtr> formatter { *this };
formatter.format(builder, reinterpret_cast<FlatPtr>(value.data()));
} else if (m_mode == Mode::Default || m_mode == Mode::HexDump) {
m_mode = Mode::HexDump;
Formatter<StringView>::format(builder, value);
} else {
Formatter<StringView>::format(builder, value);
}
}
};
template<>
struct Formatter<Bytes> : Formatter<ReadonlyBytes> {
};
template<>
struct Formatter<const char*> : Formatter<StringView> {
void format(FormatBuilder& builder, const char* value)
{
if (m_mode == Mode::Pointer) {
Formatter<FlatPtr> formatter { *this };
formatter.format(builder, reinterpret_cast<FlatPtr>(value));
} else {
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> {
void format(FormatBuilder& builder, const unsigned char* value)
{
if (m_mode == Mode::Pointer) {
Formatter<FlatPtr> formatter { *this };
formatter.format(builder, reinterpret_cast<FlatPtr>(value));
} else {
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 {
void format(FormatBuilder& builder, T* value)
{
if (m_mode == Mode::Default)
m_mode = Mode::Pointer;
Formatter<FlatPtr> formatter { *this };
formatter.format(builder, reinterpret_cast<FlatPtr>(value));
}
};
template<>
struct Formatter<char> : StandardFormatter {
void format(FormatBuilder&, char value);
};
template<>
struct Formatter<bool> : StandardFormatter {
void format(FormatBuilder&, bool value);
};
#ifndef KERNEL
template<>
struct Formatter<float> : StandardFormatter {
void format(FormatBuilder&, float value);
};
template<>
struct Formatter<double> : StandardFormatter {
Formatter() = default;
explicit Formatter(StandardFormatter formatter)
: StandardFormatter(formatter)
{
}
void format(FormatBuilder&, double value);
};
template<>
struct Formatter<long double> : StandardFormatter {
Formatter() = default;
explicit Formatter(StandardFormatter formatter)
: StandardFormatter(formatter)
{
}
void format(FormatBuilder&, long double value);
};
#endif
template<>
struct Formatter<std::nullptr_t> : Formatter<FlatPtr> {
void format(FormatBuilder& builder, std::nullptr_t)
{
if (m_mode == Mode::Default)
m_mode = Mode::Pointer;
return Formatter<FlatPtr>::format(builder, 0);
}
};
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) { vout(file, fmtstr.view(), VariadicFormatParams { parameters... }); }
template<typename... Parameters>
void outln(FILE* file, CheckedFormatString<Parameters...>&& fmtstr, const Parameters&... parameters) { vout(file, fmtstr.view(), VariadicFormatParams { parameters... }, 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)
{
vdbgln(fmtstr.view(), VariadicFormatParams { parameters... });
}
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)
{
vdmesgln(fmt.view(), VariadicFormatParams { parameters... });
}
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)
{
v_critical_dmesgln(fmt.view(), VariadicFormatParams { parameters... });
}
#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> {
void format(FormatBuilder& builder, const FormatIfSupported<T>&)
{
Formatter<StringView>::format(builder, "?");
}
};
template<typename T>
struct __FormatIfSupported<T, true> : Formatter<T> {
void format(FormatBuilder& builder, const FormatIfSupported<T>& value)
{
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<String> {
template<typename... Parameters>
void format(FormatBuilder& builder, StringView fmtstr, const Parameters&... parameters)
{
vformat(builder, fmtstr, VariadicFormatParams { parameters... });
}
void vformat(FormatBuilder& builder, StringView fmtstr, TypeErasedFormatParams params);
};
} // 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)