#include <stdio.h>
#include <stdint.h>
+#include <stdarg.h>
+#include <stdlib.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include <limits.h>
+
+#ifndef REGTEST
/* Using an integer's bits as flags for both the conversion flags and length
modifiers.
*/
+/* FIXME: one too many flags to work on a 16-bit machine, join some (e.g. the
+ width flags) into a combined field.
+*/
#define E_minus 1<<0
#define E_plus 1<<1
#define E_alt 1<<2
#define E_size 1<<11
#define E_ptrdiff 1<<12
#define E_intptr 1<<13
-#define E_double 1<<14
+#define E_ldouble 1<<14
#define E_lower 1<<15
#define E_unsigned 1<<16
n - pointer to maximum number of characters to be delivered in this call
s - the buffer into which the character shall be delivered
*/
-#define DELIVER( x ) do { if ( status->i < status->n ) { if ( status->stream != NULL ) putc( x, status->stream ); else status->s[status->i] = x; } ++(status->i); } while ( 0 )
+#define PUT( x ) \
+do { \
+ int character = x; \
+ if ( status->i < status->n ) { \
+ if ( status->stream != NULL ) \
+ putc( character, status->stream ); \
+ else \
+ status->s[status->i] = character; \
+ } \
+ ++(status->i); \
+} while ( 0 )
-/* This function recursively converts a given integer value to a given base
- into a character string. Persistent information - like the number of digits
- parsed so far - is recorded in a struct _PDCLIB_status_t, which allows to
- avoid overwriting snprintf() limits, and enables the function to do the
- necessary padding / prefixing of the character string eventually printed.
-*/
-static void int2base( intmax_t value, struct _PDCLIB_status_t * status )
+/* 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 int2base( uintmax_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->this);
- if ( ( value / status->base ) != 0 )
+ char sign = 0;
+ if ( ! ( status->flags & E_unsigned ) )
{
- /* 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.
- */
- /* 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 ) )
- {
- /* Octal / hexadecimal prefix for "%#" conversions */
- preface[ preidx++ ] = '0';
- if ( status->base == 16 )
- {
- 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 )
- {
- preface[ preidx++ ] = '+';
- }
- else if ( status->flags & E_space )
- {
- preface[ preidx++ ] = ' ';
- }
- }
- {
- size_t prec_pads = ( status->prec > status->this ) ? ( status->prec - status->this ) : 0;
- if ( ! ( status->flags & ( E_minus | 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->this > status->prec ) ? status->this : status->prec );
- if ( status->width > characters )
- {
- for ( int i = 0; i < status->width - characters; ++i )
- {
- DELIVER( ' ' );
- ++(status->this);
- }
- }
- }
- /* Now we did the padding, do the prefixes (if any). */
- preidx = 0;
- while ( preface[ preidx ] != '\0' )
+ intmax_t signval = (intmax_t) value;
+ bool negative = signval < 0;
+ value = signval < 0 ? -signval : signval;
+
+ if ( negative )
{
- DELIVER( preface[ preidx++ ] );
- ++(status->this);
- }
- if ( ( ! ( status->flags & E_minus ) ) && ( status->flags & E_zero ) )
+ sign = '-';
+ }
+ else if ( status->flags & E_plus )
{
- /* If field is not left aligned, and zero padding is requested, do
- so.
- */
- while ( status->this < status->width )
- {
- DELIVER( '0' );
- ++(status->this);
- }
+ sign = '+';
}
- /* Do the precision padding if necessary. */
- for ( int i = 0; i < prec_pads; ++i )
+ else if (status->flags & E_space )
{
- DELIVER( '0' );
- }
+ sign = ' ';
}
}
- /* Recursion tail - print the current digit. */
+
+ // 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
{
- int digit = value % status->base;
- if ( digit < 0 )
+ 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( (long) 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 ) )
{
- digit *= -1;
+ while( written < status->width )
+ {
+ outend[-++written] = '0';
+ padding++;
+ }
}
- if ( status->flags & E_lower )
+
+ // Prefixes
+ if ( sign != 0 )
{
- /* Lowercase letters. Same array used for strto...(). */
- DELIVER( _PDCLIB_digits[ digit ] );
+ if ( padding == 0 ) written++;
+ outend[-written] = sign;
}
- else
+ else if ( status->flags & E_alt )
{
- /* Uppercase letters. Array only used here, only 0-F. */
- DELIVER( _PDCLIB_Xdigits[ digit ] );
+ switch ( status->base )
+ {
+ case 8:
+ if ( outend[-written] != '0' ) outend[-++written] = '0';
+ break;
+ case 16:
+ // No prefix if zero
+ if ( value == 0 ) break;
+
+ written += padding < 2 ? 2 - padding : 0;
+ outend[-written ] = '0';
+ outend[-written + 1] = (status->flags & E_lower) ? 'x' : 'X';
+ break;
+ default:
+ break;
+ }
}
+
+ // Space padding to field width
+ if ( ! ( status->flags & ( E_minus | E_zero ) ) )
+ {
+ while( written < status->width ) outend[-++written] = ' ';
}
+
+ // Write output
+ status->current = written;
+ while ( written )
+ PUT( outend[-written--] );
}
-/* This function is to be called with spec pointing to the leading '%' of a
- printf() conversion specifier.
-*/
const char * _PDCLIB_print( const char * spec, struct _PDCLIB_status_t * status )
{
const char * orig_spec = spec;
if ( *(++spec) == '%' )
{
- DELIVER( *spec );
+ /* %% -> print single '%' */
+ PUT( *spec );
return ++spec;
}
/* Initializing status structure */
status->flags = 0;
status->base = 0;
- status->this = 0;
+ status->current = 0;
status->width = 0;
- status->prec = 0;
+ status->prec = EOF;
/* First come 0..n flags */
do
switch ( *spec )
{
case '-':
+ /* left-aligned output */
status->flags |= E_minus;
++spec;
break;
case '+':
+ /* positive numbers prefixed with '+' */
status->flags |= E_plus;
++spec;
break;
case '#':
+ /* alternative format (leading 0x for hex, 0 for octal) */
status->flags |= E_alt;
++spec;
break;
case ' ':
+ /* positive numbers prefixed with ' ' */
status->flags |= E_space;
++spec;
break;
case '0':
+ /* right-aligned padding done with '0' instead of ' ' */
status->flags |= E_zero;
++spec;
break;
default:
+ /* not a flag, exit flag parsing */
status->flags |= E_done;
break;
}
if ( *spec == '*' )
{
/* Retrieve width value from argument stack */
- if ( ( status->width = va_arg( status->arg, int ) ) < 0 )
+ int width = va_arg( status->arg, int );
+ if ( width < 0 )
{
- /* Negative value is '-' flag plus absolute value */
status->flags |= E_minus;
- status->width *= -1;
+ status->width = abs( width );
+ }
+ else
+ {
+ status->width = width;
}
++spec;
}
case 'h':
if ( *spec == 'h' )
{
+ /* hh -> char */
status->flags |= E_char;
++spec;
}
else
{
+ /* h -> short */
status->flags |= E_short;
}
break;
case 'l':
if ( *spec == 'l' )
{
+ /* ll -> long long */
status->flags |= E_llong;
++spec;
}
else
{
+ /* k -> long */
status->flags |= E_long;
}
break;
case 'j':
+ /* j -> intmax_t, which might or might not be long long */
status->flags |= E_intmax;
break;
case 'z':
+ /* z -> size_t, which might or might not be unsigned int */
status->flags |= E_size;
break;
case 't':
+ /* t -> ptrdiff_t, which might or might not be long */
status->flags |= E_ptrdiff;
break;
case 'L':
- status->flags |= E_double;
+ /* L -> long double */
+ status->flags |= E_ldouble;
break;
default:
--spec;
break;
case 'c':
/* TODO: Flags, wide chars. */
- DELIVER( va_arg( status->arg, int ) );
+ PUT( va_arg( status->arg, int ) );
return ++spec;
case 's':
/* TODO: Flags, wide chars. */
char * s = va_arg( status->arg, char * );
while ( *s != '\0' )
{
- DELIVER( *(s++) );
+ PUT( *(s++) );
}
return ++spec;
}
value = (uintmax_t)va_arg( status->arg, size_t );
break;
}
- ++(status->this);
- if ( ( value / status->base ) != 0 )
- {
- int2base( (intmax_t)(value / status->base), status );
- }
- int digit = value % status->base;
- if ( digit < 0 )
- {
- digit *= -1;
- }
- if ( status->flags & E_lower )
- {
- DELIVER( _PDCLIB_digits[ digit ] );
- }
- else
- {
- DELIVER( _PDCLIB_Xdigits[ digit ] );
- }
+ int2base( value, status );
}
else
{
}
if ( status->flags & E_minus )
{
- while ( status->this < status->width )
+ while ( status->current < status->width )
{
- DELIVER( ' ' );
- ++(status->this);
+ PUT( ' ' );
+ ++(status->current);
}
}
- if ( status->i >= status->n )
+ if ( status->i >= status->n && status->n > 0 )
{
status->s[status->n - 1] = '\0';
}
}
return ++spec;
}
+
+#endif
+
+#ifdef TEST
+#define _PDCLIB_FILEID "_PDCLIB/print.c"
+#define _PDCLIB_STRINGIO
+
+#include <_PDCLIB_test.h>
+
+#ifndef REGTEST
+static int testprintf( char * buffer, const char * format, ... )
+{
+ /* Members: base, flags, n, i, current, s, width, prec, stream, arg */
+ struct _PDCLIB_status_t status;
+ status.base = 0;
+ status.flags = 0;
+ status.n = 100;
+ status.i = 0;
+ status.current = 0;
+ status.s = buffer;
+ status.width = 0;
+ status.prec = 0;
+ status.stream = NULL;
+ va_start( status.arg, format );
+ memset( buffer, '\0', 100 );
+ if ( *(_PDCLIB_print( format, &status )) != '\0' )
+ {
+ printf( "_PDCLIB_print() did not return end-of-specifier on '%s'.\n", format );
+ ++TEST_RESULTS;
+ }
+ va_end( status.arg );
+ return status.i;
+}
+#endif
+
+#define TEST_CONVERSION_ONLY
+
+int main( void )
+{
+#ifndef REGTEST
+ char target[100];
+#include "printf_testcases.h"
+#endif
+ return TEST_RESULTS;
+}
+
+#endif
projects / pdclib / blobdiff