ladybird/AK/PrintfImplementation.h
Tim Schumacher 8c3e4ccd72 AK: Honor variable precision argument when formatting
printf didn't check whether the additional integer variable belongs to
the field width specifier or to the precision specifier, and always
applied it to the field width instead.

Implement the case distinction that we already use in literal width
and precision specifiers for the variable version as well so that
they are correctly attributed.
2021-05-30 18:45:06 +01:00

519 lines
16 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>
ALWAYS_INLINE int print_hex(PutChFunc putch, char*& 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>
ALWAYS_INLINE int print_number(PutChFunc putch, char*& 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>
ALWAYS_INLINE int print_u64(PutChFunc putch, char*& 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>
ALWAYS_INLINE int print_double(PutChFunc putch, char*& 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>
ALWAYS_INLINE int print_i64(PutChFunc putch, char*& 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>
ALWAYS_INLINE int print_octal_number(PutChFunc putch, char*& 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>
ALWAYS_INLINE int print_string(PutChFunc putch, char*& 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>
ALWAYS_INLINE int print_signed_number(PutChFunc putch, char*& 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>
struct PrintfImpl {
ALWAYS_INLINE PrintfImpl(PutChFunc& putch, char*& 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(char format_op, const char* fmt, const ModifierState&, ArgumentListRefT) const
{
dbgln("printf_internal: Unimplemented format specifier {} (fmt: {})", format_op, fmt);
return 0;
}
protected:
char*& 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 Impl = PrintfImpl, typename ArgumentListT = va_list, template<typename T, typename V = decltype(declval<ArgumentListT&>())> typename NextArgument = VaArgNextArgument>
ALWAYS_INLINE int printf_internal(PutChFunc putch, char* buffer, const char*& fmt, ArgumentListT ap)
{
int ret = 0;
char* bufptr = buffer;
Impl<PutChFunc, ArgumentListT&, NextArgument> impl { putch, bufptr, ret };
for (const char* 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.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.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 == '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;