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sortix--sortix/libc/stdio/vprintf_callback.cpp
Jonas 'Sortie' Termansen af9ea5df04 Add %m support to vprintf_callback(3).
2014-03-17 19:22:11 +01:00

463 lines
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/*******************************************************************************
Copyright(C) Jonas 'Sortie' Termansen 2011, 2012, 2013, 2014.
This file is part of the Sortix C Library.
The Sortix C Library is free software: you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation, either version 3 of the License, or (at your
option) any later version.
The Sortix C Library is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
License for more details.
You should have received a copy of the GNU Lesser General Public License
along with the Sortix C Library. If not, see <http://www.gnu.org/licenses/>.
stdio/vprintf_callback.cpp
Provides printf formatting functions that uses callbacks.
*******************************************************************************/
// Number of bugs seemingly unrelated bugs that have been traced to here:
// Countless + 2
#include <errno.h>
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <wchar.h>
static size_t convert_integer(char* destination, uintmax_t value,
uintmax_t base, const char* digits)
{
size_t result = 1;
uintmax_t copy = value;
while ( base <= copy )
copy /= base, result++;
for ( size_t i = result; i != 0; i-- )
destination[i-1] = digits[value % base],
value /= base;
return result;
}
static size_t noop_callback(void*, const char*, size_t amount)
{
return amount;
}
static
size_t callback_character(size_t (*callback)(void*, const char*, size_t),
void* user,
char c)
{
return callback(user, &c, 1);
}
extern "C"
size_t vprintf_callback(size_t (*callback)(void*, const char*, size_t),
void* user,
const char* restrict format,
va_list parameters)
{
if ( !callback )
callback = noop_callback;
size_t written = 0;
bool rejected_bad_specifier = false;
while ( *format != '\0' )
{
if ( *format != '%' )
{
print_c:
size_t amount = 1;
while ( format[amount] && format[amount] != '%' )
amount++;
if ( callback(user, format, amount) != amount )
return SIZE_MAX;
format += amount;
written += amount;
continue;
}
const char* format_begun_at = format;
if ( *(++format) == '%' )
goto print_c;
if ( rejected_bad_specifier )
{
incomprehensible_conversion:
rejected_bad_specifier = true;
unsupported_conversion:
format = format_begun_at;
goto print_c;
}
bool alternate = false;
bool zero_pad = false;
bool field_width_is_negative = false;
bool prepend_blank_if_positive = false;
bool prepend_plus_if_positive = false;
bool group_thousands = false;
bool alternate_output_digits = false;
(void) group_thousands;
(void) alternate_output_digits;
while ( true )
{
switch ( *format++ )
{
case '#': alternate = true; continue;
case '0': zero_pad = true; continue;
case '-': field_width_is_negative = true; continue;
case ' ': prepend_blank_if_positive = true; continue;
case '+': prepend_plus_if_positive = true; continue;
case '\'': group_thousands = true; continue;
case 'I': alternate_output_digits = true; continue;
default: format--; break;
}
break;
}
int field_width = 0;
if ( *format == '*' && (format++, true) )
field_width = va_arg(parameters, int);
else while ( '0' <= *format && *format <= '9' )
field_width = 10 * field_width + *format++ - '0';
if ( field_width_is_negative )
field_width = -field_width;
size_t abs_field_width = (size_t) abs(field_width);
size_t precision = SIZE_MAX;
if ( *format == '.' && (format++, true) )
{
precision = 0;
if ( *format == '*' && (format++, true) )
{
int int_precision = va_arg(parameters, int);
precision = 0 <= int_precision ? (size_t) int_precision : 0;
}
else
{
if ( *format == '-' && (format++, true) )
while ( '0' <= *format && *format <= '9' )
format++;
else
while ( '0' <= *format && *format <= '9' )
precision = 10 * precision + *format++ - '0';
}
}
enum length
{
LENGTH_SHORT_SHORT,
LENGTH_SHORT,
LENGTH_DEFAULT,
LENGTH_LONG,
LENGTH_LONG_LONG,
LENGTH_LONG_DOUBLE,
LENGTH_INTMAX_T,
LENGTH_SIZE_T,
LENGTH_PTRDIFF_T,
};
struct length_modifer
{
const char* name;
enum length length;
};
struct length_modifer length_modifiers[] =
{
{ "hh", LENGTH_SHORT_SHORT },
{ "h", LENGTH_SHORT },
{ "", LENGTH_DEFAULT },
{ "l", LENGTH_LONG },
{ "ll", LENGTH_LONG_LONG },
{ "L", LENGTH_LONG_DOUBLE },
{ "j", LENGTH_INTMAX_T },
{ "z", LENGTH_SIZE_T },
{ "t", LENGTH_PTRDIFF_T },
};
enum length length = LENGTH_DEFAULT;
size_t length_length = 0;
for ( size_t i = 0;
i < sizeof(length_modifiers) / sizeof(length_modifiers[0]);
i++ )
{
size_t name_length = strlen(length_modifiers[i].name);
if ( name_length < length_length )
continue;
if ( strncmp(format, length_modifiers[i].name, name_length) != 0 )
continue;
length = length_modifiers[i].length;
length_length = name_length;
}
format += length_length;
if ( *format == 'd' || *format == 'i' || *format == 'o' ||
*format == 'u' || *format == 'x' || *format == 'X' ||
*format == 'p' )
{
char conversion = *format++;
bool negative_value = false;
uintmax_t value;
if ( conversion == 'p' )
{
value = (uintmax_t) va_arg(parameters, void*);
conversion = 'x';
alternate = !alternate;
prepend_blank_if_positive = false;
prepend_plus_if_positive = false;
}
else if ( conversion == 'i' || conversion == 'd' )
{
intmax_t signed_value;
if ( length == LENGTH_SHORT_SHORT )
signed_value = va_arg(parameters, int);
else if ( length == LENGTH_SHORT )
signed_value = va_arg(parameters, int);
else if ( length == LENGTH_DEFAULT )
signed_value = va_arg(parameters, int);
else if ( length == LENGTH_LONG )
signed_value = va_arg(parameters, long);
else if ( length == LENGTH_LONG_LONG )
signed_value = va_arg(parameters, long long);
else if ( length == LENGTH_INTMAX_T )
signed_value = va_arg(parameters, intmax_t);
else if ( length == LENGTH_SIZE_T )
signed_value = va_arg(parameters, ssize_t);
else if ( length == LENGTH_PTRDIFF_T )
signed_value = va_arg(parameters, ptrdiff_t);
else
goto incomprehensible_conversion;
value = (negative_value = signed_value < 0) ?
- (uintmax_t) signed_value : signed_value;
}
else
{
if ( length == LENGTH_SHORT_SHORT )
value = va_arg(parameters, unsigned int);
else if ( length == LENGTH_SHORT )
value = va_arg(parameters, unsigned int);
else if ( length == LENGTH_DEFAULT )
value = va_arg(parameters, unsigned int);
else if ( length == LENGTH_LONG )
value = va_arg(parameters, unsigned long);
else if ( length == LENGTH_LONG_LONG )
value = va_arg(parameters, unsigned long long);
else if ( length == LENGTH_INTMAX_T )
value = va_arg(parameters, uintmax_t);
else if ( length == LENGTH_SIZE_T )
value = va_arg(parameters, size_t);
else if ( length == LENGTH_PTRDIFF_T )
value = (uintmax_t) va_arg(parameters, ptrdiff_t);
else
goto incomprehensible_conversion;
prepend_blank_if_positive = false;
prepend_plus_if_positive = false;
}
const char* digits = conversion == 'X' ? "0123456789ABCDEF" :
"0123456789abcdef";
uintmax_t base = (conversion == 'x' || conversion == 'X') ? 16 :
conversion == 'o' ? 8 : 10;
char prefix[3];
size_t prefix_length = 0;
size_t prefix_digits_length = 0;
if ( negative_value )
prefix[prefix_length++] = '-';
else if ( prepend_plus_if_positive )
prefix[prefix_length++] = '+';
else if ( prepend_blank_if_positive )
prefix[prefix_length++] = ' ';
if ( alternate && (conversion == 'x' || conversion == 'X') && value != 0 )
prefix[prefix_digits_length++, prefix_length++] = '0',
prefix[prefix_digits_length++, prefix_length++] = conversion;
if ( alternate && conversion == 'o' && value != 0 )
prefix[prefix_digits_length++, prefix_length++] = '0';
char output[sizeof(uintmax_t) * 3];
size_t output_length = convert_integer(output, value, base, digits);
if ( !precision && output_length == 1 && output[0] == '0' )
{
output_length = 0;
output[0] = '\0';
}
size_t output_length_with_precision =
precision != SIZE_MAX && output_length < precision ?
precision :
output_length;
size_t digits_length = prefix_digits_length + output_length;
size_t normal_length = prefix_length + output_length;
size_t length_with_precision = prefix_length + output_length_with_precision;
bool use_precision = precision != SIZE_MAX;
bool use_zero_pad = zero_pad && 0 <= field_width && !use_precision;
bool use_left_pad = !use_zero_pad && 0 <= field_width;
bool use_right_pad = !use_zero_pad && field_width < 0;
if ( use_left_pad )
for ( size_t i = length_with_precision; i < abs_field_width; i++ )
if ( callback_character(callback, user, ' ') != 1 )
return SIZE_MAX;
else
written++;
if ( callback(user, prefix, prefix_length) != prefix_length )
return SIZE_MAX;
written += prefix_length;
if ( use_zero_pad )
for ( size_t i = normal_length; i < abs_field_width; i++ )
if ( callback_character(callback, user, '0') != 1 )
return SIZE_MAX;
else
written++;
if ( use_precision )
for ( size_t i = digits_length; i < precision; i++ )
if ( callback_character(callback, user, '0') != 1 )
return SIZE_MAX;
else
written++;
if ( callback(user, output, output_length) != output_length )
return SIZE_MAX;
written += output_length;
if ( use_right_pad )
for ( size_t i = length_with_precision; i < abs_field_width; i++ )
if ( callback_character(callback, user, ' ') != 1 )
return SIZE_MAX;
else
written++;
}
else if ( *format == 'e' || *format == 'E' ||
*format == 'f' || *format == 'F' ||
*format == 'g' || *format == 'G' ||
*format == 'a' || *format == 'A' )
{
char conversion = *format++;
long double value;
if ( length == LENGTH_DEFAULT )
value = va_arg(parameters, double);
else if ( length == LENGTH_LONG_DOUBLE )
value = va_arg(parameters, long double);
else
goto incomprehensible_conversion;
// TODO: Implement floating-point printing.
(void) conversion;
(void) value;
goto unsupported_conversion;
}
else if ( *format == 'c' && (format++, true) )
{
char c;
if ( length == LENGTH_DEFAULT )
c = (char) va_arg(parameters, int);
else if ( length == LENGTH_LONG )
{
// TODO: Implement wide character printing.
(void) va_arg(parameters, wint_t);
goto unsupported_conversion;
}
else
goto incomprehensible_conversion;
if ( !field_width_is_negative && 1 < abs_field_width )
for ( size_t i = 1; i < abs_field_width; i++ )
if ( callback_character(callback, user, ' ') != 1 )
return SIZE_MAX;
else
written++;
if ( callback(user, &c, 1) != 1 )
return SIZE_MAX;
written++;
if ( field_width_is_negative && 1 < abs_field_width )
for ( size_t i = 1; i < abs_field_width; i++ )
if ( callback_character(callback, user, ' ') != 1 )
return SIZE_MAX;
else
written++;
}
else if ( *format == 'm' || *format == 's' )
{
char conversion = *format++;
const char* string;
if ( conversion == 'm' )
string = strerror(errno), conversion = 's';
else if ( length == LENGTH_DEFAULT )
string = va_arg(parameters, const char*);
else if ( length == LENGTH_LONG )
{
// TODO: Implement wide character string printing.
(void) va_arg(parameters, const wchar_t*);
goto unsupported_conversion;
}
else
goto incomprehensible_conversion;
size_t string_length = 0;
for ( size_t i = 0; i < precision && string[i]; i++ )
string_length++;
if ( !field_width_is_negative && string_length < abs_field_width )
for ( size_t i = string_length; i < abs_field_width; i++ )
if ( callback_character(callback, user, ' ') != 1 )
return SIZE_MAX;
else
written++;
if ( callback(user, string, string_length) != string_length )
return SIZE_MAX;
written += string_length;
if ( field_width_is_negative && string_length < abs_field_width )
for ( size_t i = string_length; i < abs_field_width; i++ )
if ( callback_character(callback, user, ' ') != 1 )
return SIZE_MAX;
else
written++;
}
else if ( *format == 'n' && (format++, true) )
{
if ( length == LENGTH_SHORT_SHORT )
*va_arg(parameters, signed char*) = (signed char) written;
else if ( length == LENGTH_SHORT )
*va_arg(parameters, short*) = (short) written;
else if ( length == LENGTH_DEFAULT )
*va_arg(parameters, int*) = (int) written;
else if ( length == LENGTH_LONG )
*va_arg(parameters, long*) = (long) written;
else if ( length == LENGTH_LONG_LONG )
*va_arg(parameters, long long*) = (long long) written;
else if ( length == LENGTH_INTMAX_T )
*va_arg(parameters, uintmax_t*) = (uintmax_t) written;
else if ( length == LENGTH_SIZE_T )
*va_arg(parameters, size_t*) = (size_t) written;
else if ( length == LENGTH_PTRDIFF_T )
*va_arg(parameters, ptrdiff_t*) = (ptrdiff_t) written;
else
goto incomprehensible_conversion;
}
else
goto incomprehensible_conversion;
}
return written;
}
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