ladybird/AK/PrintfImplementation.h
2021-12-21 21:24:36 +03:30

527 lines
17 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/Format.h>
#include <AK/StdLibExtras.h>
#include <AK/Types.h>
#include <stdarg.h>
#ifdef __serenity__
extern "C" size_t strlen(const char*);
#else
# include <string.h>
#endif
namespace PrintfImplementation {
template<typename PutChFunc, typename T, typename CharType>
ALWAYS_INLINE int print_hex(PutChFunc putch, CharType*& bufptr, T number, bool upper_case, bool alternate_form, bool left_pad, bool zero_pad, u8 field_width)
{
int ret = 0;
int digits = 0;
for (T n = number; n > 0; n >>= 4)
++digits;
if (digits == 0)
digits = 1;
if (left_pad) {
int stop_at = field_width - digits;
if (alternate_form)
stop_at -= 2;
while (ret < stop_at) {
putch(bufptr, ' ');
++ret;
}
}
if (alternate_form) {
putch(bufptr, '0');
putch(bufptr, 'x');
ret += 2;
field_width += 2;
}
if (zero_pad) {
while (ret < field_width - digits) {
putch(bufptr, '0');
++ret;
}
}
if (number == 0) {
putch(bufptr, '0');
++ret;
} else {
u8 shift_count = digits * 4;
while (shift_count) {
constexpr const char* printf_hex_digits_lower = "0123456789abcdef";
constexpr const char* printf_hex_digits_upper = "0123456789ABCDEF";
shift_count -= 4;
putch(bufptr,
upper_case
? printf_hex_digits_upper[(number >> shift_count) & 0x0f]
: printf_hex_digits_lower[(number >> shift_count) & 0x0f]);
++ret;
}
}
return ret;
}
template<typename PutChFunc, typename CharType>
ALWAYS_INLINE int print_number(PutChFunc putch, CharType*& bufptr, u32 number, bool left_pad, bool zero_pad, u32 field_width)
{
u32 divisor = 1000000000;
char ch;
char padding = 1;
char buf[16];
char* p = buf;
for (;;) {
ch = '0' + (number / divisor);
number %= divisor;
if (ch != '0')
padding = 0;
if (!padding || divisor == 1)
*(p++) = ch;
if (divisor == 1)
break;
divisor /= 10;
}
size_t numlen = p - buf;
if (!field_width || field_width < numlen)
field_width = numlen;
if (!left_pad) {
for (unsigned i = 0; i < field_width - numlen; ++i) {
putch(bufptr, zero_pad ? '0' : ' ');
}
}
for (unsigned i = 0; i < numlen; ++i) {
putch(bufptr, buf[i]);
}
if (left_pad) {
for (unsigned i = 0; i < field_width - numlen; ++i) {
putch(bufptr, ' ');
}
}
return field_width;
}
template<typename PutChFunc, typename CharType>
ALWAYS_INLINE int print_u64(PutChFunc putch, CharType*& bufptr, u64 number, bool left_pad, bool zero_pad, u32 field_width)
{
u64 divisor = 10000000000000000000LLU;
char ch;
char padding = 1;
char buf[16];
char* p = buf;
for (;;) {
ch = '0' + (number / divisor);
number %= divisor;
if (ch != '0')
padding = 0;
if (!padding || divisor == 1)
*(p++) = ch;
if (divisor == 1)
break;
divisor /= 10;
}
size_t numlen = p - buf;
if (!field_width || field_width < numlen)
field_width = numlen;
if (!left_pad) {
for (unsigned i = 0; i < field_width - numlen; ++i) {
putch(bufptr, zero_pad ? '0' : ' ');
}
}
for (unsigned i = 0; i < numlen; ++i) {
putch(bufptr, buf[i]);
}
if (left_pad) {
for (unsigned i = 0; i < field_width - numlen; ++i) {
putch(bufptr, ' ');
}
}
return field_width;
}
template<typename PutChFunc, typename CharType>
ALWAYS_INLINE int print_double(PutChFunc putch, CharType*& bufptr, double number, bool left_pad, bool zero_pad, u32 field_width, u32 fraction_length)
{
int length = 0;
if (number < 0) {
putch(bufptr, '-');
length++;
number = 0 - number;
}
length = print_u64(putch, bufptr, (i64)number, left_pad, zero_pad, field_width);
putch(bufptr, '.');
length++;
double fraction = number - (i64)number;
for (u32 i = 0; i < fraction_length; ++i)
fraction = fraction * 10;
return length + print_u64(putch, bufptr, (i64)fraction, false, true, fraction_length);
}
template<typename PutChFunc, typename CharType>
ALWAYS_INLINE int print_i64(PutChFunc putch, CharType*& bufptr, i64 number, bool left_pad, bool zero_pad, u32 field_width)
{
// FIXME: This won't work if there is padding. ' -17' becomes '- 17'.
if (number < 0) {
putch(bufptr, '-');
return print_u64(putch, bufptr, 0 - number, left_pad, zero_pad, field_width) + 1;
}
return print_u64(putch, bufptr, number, left_pad, zero_pad, field_width);
}
template<typename PutChFunc, typename CharType>
ALWAYS_INLINE int print_octal_number(PutChFunc putch, CharType*& bufptr, u32 number, bool left_pad, bool zero_pad, u32 field_width)
{
u32 divisor = 134217728;
char ch;
char padding = 1;
char buf[32];
char* p = buf;
for (;;) {
ch = '0' + (number / divisor);
number %= divisor;
if (ch != '0')
padding = 0;
if (!padding || divisor == 1)
*(p++) = ch;
if (divisor == 1)
break;
divisor /= 8;
}
size_t numlen = p - buf;
if (!field_width || field_width < numlen)
field_width = numlen;
if (!left_pad) {
for (unsigned i = 0; i < field_width - numlen; ++i) {
putch(bufptr, zero_pad ? '0' : ' ');
}
}
for (unsigned i = 0; i < numlen; ++i) {
putch(bufptr, buf[i]);
}
if (left_pad) {
for (unsigned i = 0; i < field_width - numlen; ++i) {
putch(bufptr, ' ');
}
}
return field_width;
}
template<typename PutChFunc, typename CharType>
ALWAYS_INLINE int print_string(PutChFunc putch, CharType*& bufptr, const char* str, size_t len, bool left_pad, size_t field_width, bool dot, size_t fraction_length, bool has_fraction)
{
if (has_fraction)
len = min(len, fraction_length);
if (!dot && (!field_width || field_width < len))
field_width = len;
if (has_fraction && !field_width)
field_width = len;
size_t pad_amount = field_width > len ? field_width - len : 0;
if (!left_pad) {
for (size_t i = 0; i < pad_amount; ++i)
putch(bufptr, ' ');
}
for (size_t i = 0; i < min(len, field_width); ++i) {
putch(bufptr, str[i]);
}
if (left_pad) {
for (size_t i = 0; i < pad_amount; ++i)
putch(bufptr, ' ');
}
return field_width;
}
template<typename PutChFunc, typename CharType>
ALWAYS_INLINE int print_signed_number(PutChFunc putch, CharType*& bufptr, int number, bool left_pad, bool zero_pad, u32 field_width, bool always_sign)
{
if (number < 0) {
putch(bufptr, '-');
return print_number(putch, bufptr, 0 - number, left_pad, zero_pad, field_width) + 1;
}
if (always_sign)
putch(bufptr, '+');
return print_number(putch, bufptr, number, left_pad, zero_pad, field_width) + always_sign;
}
struct ModifierState {
bool left_pad { false };
bool zero_pad { false };
bool dot { false };
unsigned field_width { 0 };
bool has_fraction_length { false };
unsigned fraction_length { 6 };
unsigned long_qualifiers { 0 };
bool size_qualifier { false };
bool alternate_form { 0 };
bool always_sign { false };
};
template<typename PutChFunc, typename ArgumentListRefT, template<typename T, typename U = ArgumentListRefT> typename NextArgument, typename CharType = char>
struct PrintfImpl {
ALWAYS_INLINE PrintfImpl(PutChFunc& putch, CharType*& bufptr, const int& nwritten)
: m_bufptr(bufptr)
, m_nwritten(nwritten)
, m_putch(putch)
{
}
ALWAYS_INLINE int format_s(const ModifierState& state, ArgumentListRefT ap) const
{
const char* sp = NextArgument<const char*>()(ap);
if (!sp)
sp = "(null)";
return print_string(m_putch, m_bufptr, sp, strlen(sp), state.left_pad, state.field_width, state.dot, state.fraction_length, state.has_fraction_length);
}
ALWAYS_INLINE int format_d(const ModifierState& state, ArgumentListRefT ap) const
{
if (state.long_qualifiers >= 2)
return print_i64(m_putch, m_bufptr, NextArgument<i64>()(ap), state.left_pad, state.zero_pad, state.field_width);
return print_signed_number(m_putch, m_bufptr, NextArgument<int>()(ap), state.left_pad, state.zero_pad, state.field_width, state.always_sign);
}
ALWAYS_INLINE int format_i(const ModifierState& state, ArgumentListRefT ap) const
{
return format_d(state, ap);
}
ALWAYS_INLINE int format_u(const ModifierState& state, ArgumentListRefT ap) const
{
if (state.long_qualifiers >= 2)
return print_u64(m_putch, m_bufptr, NextArgument<u64>()(ap), state.left_pad, state.zero_pad, state.field_width);
return print_number(m_putch, m_bufptr, NextArgument<u32>()(ap), state.left_pad, state.zero_pad, state.field_width);
}
ALWAYS_INLINE int format_Q(const ModifierState& state, ArgumentListRefT ap) const
{
return print_u64(m_putch, m_bufptr, NextArgument<u64>()(ap), state.left_pad, state.zero_pad, state.field_width);
}
ALWAYS_INLINE int format_q(const ModifierState& state, ArgumentListRefT ap) const
{
return print_hex(m_putch, m_bufptr, NextArgument<u64>()(ap), false, false, state.left_pad, state.zero_pad, 16);
}
ALWAYS_INLINE int format_g(const ModifierState& state, ArgumentListRefT ap) const
{
return format_f(state, ap);
}
ALWAYS_INLINE int format_f(const ModifierState& state, ArgumentListRefT ap) const
{
return print_double(m_putch, m_bufptr, NextArgument<double>()(ap), state.left_pad, state.zero_pad, state.field_width, state.fraction_length);
}
ALWAYS_INLINE int format_o(const ModifierState& state, ArgumentListRefT ap) const
{
if (state.alternate_form)
m_putch(m_bufptr, '0');
return (state.alternate_form ? 1 : 0) + print_octal_number(m_putch, m_bufptr, NextArgument<u32>()(ap), state.left_pad, state.zero_pad, state.field_width);
}
ALWAYS_INLINE int format_x(const ModifierState& state, ArgumentListRefT ap) const
{
if (state.long_qualifiers >= 2)
return print_hex(m_putch, m_bufptr, NextArgument<u64>()(ap), false, state.alternate_form, state.left_pad, state.zero_pad, state.field_width);
return print_hex(m_putch, m_bufptr, NextArgument<u32>()(ap), false, state.alternate_form, state.left_pad, state.zero_pad, state.field_width);
}
ALWAYS_INLINE int format_X(const ModifierState& state, ArgumentListRefT ap) const
{
if (state.long_qualifiers >= 2)
return print_hex(m_putch, m_bufptr, NextArgument<u64>()(ap), true, state.alternate_form, state.left_pad, state.zero_pad, state.field_width);
return print_hex(m_putch, m_bufptr, NextArgument<u32>()(ap), true, state.alternate_form, state.left_pad, state.zero_pad, state.field_width);
}
ALWAYS_INLINE int format_n(const ModifierState&, ArgumentListRefT ap) const
{
*NextArgument<int*>()(ap) = m_nwritten;
return 0;
}
ALWAYS_INLINE int format_p(const ModifierState&, ArgumentListRefT ap) const
{
return print_hex(m_putch, m_bufptr, NextArgument<FlatPtr>()(ap), false, true, false, true, 8);
}
ALWAYS_INLINE int format_P(const ModifierState&, ArgumentListRefT ap) const
{
return print_hex(m_putch, m_bufptr, NextArgument<FlatPtr>()(ap), true, true, false, true, 8);
}
ALWAYS_INLINE int format_percent(const ModifierState&, ArgumentListRefT) const
{
m_putch(m_bufptr, '%');
return 1;
}
ALWAYS_INLINE int format_c(const ModifierState& state, ArgumentListRefT ap) const
{
char c = NextArgument<int>()(ap);
return print_string(m_putch, m_bufptr, &c, 1, state.left_pad, state.field_width, state.dot, state.fraction_length, state.has_fraction_length);
}
ALWAYS_INLINE int format_unrecognized(CharType format_op, const CharType* fmt, const ModifierState&, ArgumentListRefT) const
{
dbgln("printf_internal: Unimplemented format specifier {} (fmt: {})", format_op, fmt);
return 0;
}
protected:
CharType*& m_bufptr;
const int& m_nwritten;
PutChFunc& m_putch;
};
template<typename T, typename V>
struct VaArgNextArgument {
ALWAYS_INLINE T operator()(V ap) const
{
return va_arg(ap, T);
}
};
#define PRINTF_IMPL_DELEGATE_TO_IMPL(c) \
case* #c: \
ret += impl.format_##c(state, ap); \
break;
template<typename PutChFunc, template<typename T, typename U, template<typename X, typename Y> typename V, typename C = char> typename Impl = PrintfImpl, typename ArgumentListT = va_list, template<typename T, typename V = decltype(declval<ArgumentListT&>())> typename NextArgument = VaArgNextArgument, typename CharType = char>
ALWAYS_INLINE int printf_internal(PutChFunc putch, IdentityType<CharType>* buffer, const CharType*& fmt, ArgumentListT ap)
{
int ret = 0;
CharType* bufptr = buffer;
Impl<PutChFunc, ArgumentListT&, NextArgument, CharType> impl { putch, bufptr, ret };
for (const CharType* p = fmt; *p; ++p) {
ModifierState state;
if (*p == '%' && *(p + 1)) {
one_more:
++p;
if (*p == '.') {
state.dot = true;
if (*(p + 1))
goto one_more;
}
if (*p == '-') {
state.left_pad = true;
if (*(p + 1))
goto one_more;
}
if (*p == '+') {
state.always_sign = true;
if (*(p + 1))
goto one_more;
}
if (!state.zero_pad && !state.field_width && !state.has_fraction_length && *p == '0') {
state.zero_pad = true;
if (*(p + 1))
goto one_more;
}
if (*p >= '0' && *p <= '9') {
if (!state.dot) {
state.field_width *= 10;
state.field_width += *p - '0';
if (*(p + 1))
goto one_more;
} else {
if (!state.has_fraction_length) {
state.has_fraction_length = true;
state.zero_pad = true;
state.fraction_length = 0;
}
state.fraction_length *= 10;
state.fraction_length += *p - '0';
if (*(p + 1))
goto one_more;
}
}
if (*p == '*') {
if (state.dot) {
state.has_fraction_length = true;
state.zero_pad = true;
state.fraction_length = NextArgument<int>()(ap);
} else {
state.field_width = NextArgument<int>()(ap);
}
if (*(p + 1))
goto one_more;
}
if (*p == 'l') {
++state.long_qualifiers;
if (*(p + 1))
goto one_more;
}
if (*p == 'L') {
// TODO: Implement this properly.
// For now just swallow, so the contents are actually rendered.
if (*(p + 1))
goto one_more;
}
if (*p == 'z') {
state.size_qualifier = true;
if (*(p + 1))
goto one_more;
}
if (*p == '#') {
state.alternate_form = true;
if (*(p + 1))
goto one_more;
}
switch (*p) {
case '%':
ret += impl.format_percent(state, ap);
break;
PRINTF_IMPL_DELEGATE_TO_IMPL(P);
PRINTF_IMPL_DELEGATE_TO_IMPL(Q);
PRINTF_IMPL_DELEGATE_TO_IMPL(X);
PRINTF_IMPL_DELEGATE_TO_IMPL(c);
PRINTF_IMPL_DELEGATE_TO_IMPL(d);
#ifndef KERNEL
PRINTF_IMPL_DELEGATE_TO_IMPL(f);
PRINTF_IMPL_DELEGATE_TO_IMPL(g);
#endif
PRINTF_IMPL_DELEGATE_TO_IMPL(i);
PRINTF_IMPL_DELEGATE_TO_IMPL(n);
PRINTF_IMPL_DELEGATE_TO_IMPL(o);
PRINTF_IMPL_DELEGATE_TO_IMPL(p);
PRINTF_IMPL_DELEGATE_TO_IMPL(q);
PRINTF_IMPL_DELEGATE_TO_IMPL(s);
PRINTF_IMPL_DELEGATE_TO_IMPL(u);
PRINTF_IMPL_DELEGATE_TO_IMPL(x);
default:
ret += impl.format_unrecognized(*p, fmt, state, ap);
break;
}
} else {
putch(bufptr, *p);
++ret;
}
}
return ret;
}
#undef PRINTF_IMPL_DELEGATE_TO_IMPL
}
using PrintfImplementation::printf_internal;