#include <stdarg.h>
#include <stdlib.h>
#include <stddef.h>
+#include <stdbool.h>
+#include <limits.h>
#ifndef REGTEST
++(status->i); \
} while ( 0 )
+/* Maximum number of output characters =
+ * number of bits in (u)intmax_t / number of bits per character in smallest
+ * base. Smallest base is octal, 3 bits/char.
+ *
+ * Additionally require 2 extra characters for prefixes
+ */
+static const size_t maxIntLen = sizeof(intmax_t) * CHAR_BIT / 3 + 1;
-static void intformat( intmax_t value, struct _PDCLIB_status_t * status )
+static void int2base( uintmax_t value, struct _PDCLIB_status_t * status )
{
- /* At worst, we need two prefix characters (hex prefix). */
- char preface[3] = "\0";
- size_t preidx = 0;
- if ( ( status->flags & E_alt ) && ( status->base == 16 || status->base == 8 ) )
+ char sign = 0;
+ if ( ! ( status->flags & E_unsigned ) )
{
- /* Octal / hexadecimal prefix for "%#" conversions */
- preface[ preidx++ ] = '0';
- if ( status->base == 16 )
+ intmax_t signval = (intmax_t) value;
+ bool negative = signval < 0;
+ value = signval < 0 ? -signval : signval;
+
+ if ( negative )
{
- preface[ preidx++ ] = ( status->flags & E_lower ) ? 'x' : 'X';
- }
- }
- if ( value < 0 )
- {
- /* Negative sign for negative values - at all times. */
- preface[ preidx++ ] = '-';
- }
- else if ( ! ( status->flags & E_unsigned ) )
- {
- /* plus sign / extra space are only for unsigned conversions */
- if ( status->flags & E_plus )
+ sign = '-';
+ }
+ else if ( status->flags & E_plus )
{
- preface[ preidx++ ] = '+';
+ sign = '+';
}
- else if ( status->flags & E_space )
+ else if (status->flags & E_space )
{
- preface[ preidx++ ] = ' ';
+ sign = ' ';
}
}
+
+ // The user could theoretically ask for a silly buffer length here.
+ // Perhaps after a certain size we should malloc? Or do we refuse to protect
+ // them from their own stupidity?
+ size_t bufLen = (status->width > maxIntLen ? status->width : maxIntLen) + 2;
+ char outbuf[bufLen];
+ char * outend = outbuf + bufLen;
+ unsigned written = 0;
+
+ // Build up our output string - backwards
{
- size_t prec_pads = ( status->prec > status->current ) ? ( status->prec - status->current ) : 0;
- if ( ! ( status->flags & ( E_minus | E_zero ) ) )
+ const char * digits = (status->flags & E_lower) ?
+ _PDCLIB_digits : _PDCLIB_Xdigits;
+ uintmax_t remaining = value;
+ do {
+ uintmax_t digit = remaining % status->base;
+ remaining /= status->base;
+
+ outend[-++written] = digits[digit];
+ } while(remaining != 0);
+ }
+
+ // Pad field out to the precision specification
+ while( written < status->prec ) outend[-++written] = '0';
+
+ // If a field width specified, and zero padding was requested, then pad to
+ // the field width
+ unsigned padding = 0;
+ if ( ( ! ( status->flags & E_minus ) ) && ( status->flags & E_zero ) )
{
- /* Space padding is only done if no zero padding or left alignment
- is requested. Leave space for any prefixes determined above.
- */
- /* The number of characters to be printed, plus prefixes if any. */
- /* This line contained probably the most stupid, time-wasting bug
- I've ever perpetrated. Greetings to Samface, DevL, and all
- sceners at Breakpoint 2006.
- */
- size_t characters = preidx + ( ( status->current > status->prec ) ? status->current : status->prec );
- if ( status->width > characters )
+ while( written < status->width )
{
- for ( size_t i = 0; i < status->width - characters; ++i )
- {
- PUT( ' ' );
- ++(status->current);
- }
+ outend[-++written] = '0';
+ padding++;
}
}
- /* Now we did the padding, do the prefixes (if any). */
- preidx = 0;
- while ( preface[ preidx ] != '\0' )
+
+ // Prefixes
+ if ( sign != 0 )
{
- PUT( preface[ preidx++ ] );
- ++(status->current);
+ if ( padding == 0 ) written++;
+ outend[-written] = sign;
}
- if ( ( ! ( status->flags & E_minus ) ) && ( status->flags & E_zero ) )
+ else if ( status->flags & E_alt )
{
- /* If field is not left aligned, and zero padding is requested, do
- so.
- */
- while ( status->current < status->width )
+ switch ( status->base )
{
- PUT( '0' );
- ++(status->current);
+ case 8:
+ if ( outend[-written] != '0' ) outend[-++written] = '0';
+ break;
+ case 16:
+ written += padding < 2 ? 2 - padding : 0;
+ outend[-written ] = '0';
+ outend[-written + 1] = (status->flags & E_lower) ? 'x' : 'X';
+ break;
+ default:
+ break;
}
}
- /* Do the precision padding if necessary. */
- for ( size_t i = 0; i < prec_pads; ++i )
- {
- PUT( '0' );
- }
- }
-}
-
-/* This function recursively converts a given integer value to a character
- stream. The conversion is done under the control of a given status struct
- and written either to a character string or a stream, depending on that
- same status struct. The status struct also keeps the function from exceeding
- snprintf() limits, and enables any necessary padding / prefixing of the
- output once the number of characters to be printed is known, which happens
- at the lowermost recursion level.
-*/
-static void int2base( intmax_t value, struct _PDCLIB_status_t * status )
-{
- /* Registering the character being printed at the end of the function here
- already so it will be taken into account when the deepestmost recursion
- does the prefix / padding stuff.
- */
- ++(status->current);
- if ( ( value / status->base ) != 0 )
- {
- /* More digits to be done - recurse deeper */
- int2base( value / status->base, status );
- }
- else
- {
- /* We reached the last digit, the deepest point of our recursion, and
- only now know how long the number to be printed actually is. Now we
- have to do the sign, prefix, width, and precision padding stuff
- before printing the numbers while we resurface from the recursion.
- */
- intformat( value, status );
- }
- /* Recursion tail - print the current digit. */
- {
- int digit = value % status->base;
- if ( digit < 0 )
- {
- digit *= -1;
- }
- if ( status->flags & E_lower )
- {
- /* Lowercase letters. Same array used for strto...(). */
- PUT( _PDCLIB_digits[ digit ] );
- }
- else
+ // Space padding to field width
+ if ( ! ( status->flags & ( E_minus | E_zero ) ) )
{
- /* Uppercase letters. Array only used here, only 0-F. */
- PUT( _PDCLIB_Xdigits[ digit ] );
+ while( written < status->width ) outend[-++written] = ' ';
}
- }
-}
+ // Write output
+ status->current = written;
+ while ( written )
+ PUT( outend[-written--] );
+}
const char * _PDCLIB_print( const char * spec, struct _PDCLIB_status_t * status )
{
value = (uintmax_t)va_arg( status->arg, size_t );
break;
}
- ++(status->current);
- /* FIXME: The if clause means one-digit values do not get formatted */
- /* Was introduced originally to get value to "safe" levels re. uintmax_t. */
- if ( ( value / status->base ) != 0 )
- {
- int2base( (intmax_t)(value / status->base), status );
- }
- else
- {
- intformat( (intmax_t)value, status );
- }
- int digit = value % status->base;
- if ( digit < 0 )
- {
- digit *= -1;
- }
- if ( status->flags & E_lower )
- {
- PUT( _PDCLIB_digits[ digit ] );
- }
- else
- {
- PUT( _PDCLIB_Xdigits[ digit ] );
- }
+ int2base( value, status );
}
else
{
projects / pdclib.old / commitdiff