--- /dev/null
+/* FIXME: to be removed one day; for now we explicitly are not
+ * prepared to support the POSIX-XSI additions to the C99 standard.
+ */
+#undef WITH_XSI_FEATURES
+
+/* pformat.c
+ *
+ * $Id$
+ *
+ * Provides a core implementation of the formatting capabilities
+ * common to the entire `printf()' family of functions; it conforms
+ * generally to C99 and SUSv3/POSIX specifications, with extensions
+ * to support Microsoft's non-standard format specifications.
+ *
+ * Written by Keith Marshall <keithmarshall@users.sourceforge.net>
+ *
+ * This is free software. You may redistribute and/or modify it as you
+ * see fit, without restriction of copyright.
+ *
+ * This software is provided "as is", in the hope that it may be useful,
+ * but WITHOUT WARRANTY OF ANY KIND, not even any implied warranty of
+ * MERCHANTABILITY, nor of FITNESS FOR ANY PARTICULAR PURPOSE. At no
+ * time will the author accept any form of liability for any damages,
+ * however caused, resulting from the use of this software.
+ *
+ * The elements of this implementation which deal with the formatting
+ * of floating point numbers, (i.e. the `%e', `%E', `%f', `%F', `%g'
+ * and `%G' format specifiers, but excluding the hexadecimal floating
+ * point `%a' and `%A' specifiers), make use of the `__gdtoa' function
+ * written by David M. Gay, and are modelled on his sample code, which
+ * has been deployed under its accompanying terms of use:--
+ *
+ ******************************************************************
+ * Copyright (C) 1997, 1999, 2001 Lucent Technologies
+ * All Rights Reserved
+ *
+ * Permission to use, copy, modify, and distribute this software and
+ * its documentation for any purpose and without fee is hereby
+ * granted, provided that the above copyright notice appear in all
+ * copies and that both that the copyright notice and this
+ * permission notice and warranty disclaimer appear in supporting
+ * documentation, and that the name of Lucent or any of its entities
+ * not be used in advertising or publicity pertaining to
+ * distribution of the software without specific, written prior
+ * permission.
+ *
+ * LUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+ * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.
+ * IN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES BE LIABLE FOR ANY
+ * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER
+ * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
+ * ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
+ * THIS SOFTWARE.
+ ******************************************************************
+ *
+ */
+#include <stdio.h>
+#include <stdarg.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <limits.h>
+#include <locale.h>
+#include <wchar.h>
+#include <math.h>
+
+/* FIXME: The following belongs in values.h, but current MinGW
+ * has nothing useful there! OTOH, values.h is not a standard
+ * header, and it's use may be considered obsolete; perhaps it
+ * is better to just keep these definitions here.
+ */
+#ifndef _VALUES_H
+/*
+ * values.h
+ *
+ */
+#define _VALUES_H
+
+#include <limits.h>
+
+#define _TYPEBITS(type) (sizeof(type) * CHAR_BIT)
+
+#define LLONGBITS _TYPEBITS(long long)
+
+#endif /* !defined _VALUES_H -- end of file */
+
+#include "pformat.h"
+
+/* Bit-map constants, defining the internal format control
+ * states, which propagate through the flags.
+ */
+#define PFORMAT_HASHED 0x0800
+#define PFORMAT_LJUSTIFY 0x0400
+#define PFORMAT_ZEROFILL 0x0200
+
+#define PFORMAT_JUSTIFY (PFORMAT_LJUSTIFY | PFORMAT_ZEROFILL)
+#define PFORMAT_IGNORE -1
+
+#define PFORMAT_SIGNED 0x01C0
+#define PFORMAT_POSITIVE 0x0100
+#define PFORMAT_NEGATIVE 0x0080
+#define PFORMAT_ADDSPACE 0x0040
+
+#define PFORMAT_XCASE 0x0020
+
+#define PFORMAT_LDOUBLE 0x0004
+
+/* `%o' format digit extraction mask, and shift count...
+ * (These are constant, and do not propagate through the flags).
+ */
+#define PFORMAT_OMASK 0x0007
+#define PFORMAT_OSHIFT 0x0003
+
+/* `%x' and `%X' format digit extraction mask, and shift count...
+ * (These are constant, and do not propagate through the flags).
+ */
+#define PFORMAT_XMASK 0x000F
+#define PFORMAT_XSHIFT 0x0004
+
+/* The radix point character, used in floating point formats, is
+ * localised on the basis of the active LC_NUMERIC locale category.
+ * It is stored locally, as a `wchar_t' entity, which is converted
+ * to a (possibly multibyte) character on output. Initialisation
+ * of the stored `wchar_t' entity, together with a record of its
+ * effective multibyte character length, is required each time
+ * `__pformat()' is entered, (static storage would not be thread
+ * safe), but this initialisation is deferred until it is actually
+ * needed; on entry, the effective character length is first set to
+ * the following value, (and the `wchar_t' entity is zeroed), to
+ * indicate that a call of `localeconv()' is needed, to complete
+ * the initialisation.
+ */
+#define PFORMAT_RPINIT -3
+
+/* The floating point format handlers return the following value
+ * for the radix point position index, when the argument value is
+ * infinite, or not a number.
+ */
+#define PFORMAT_INFNAN -32768
+
+#ifdef _WIN32
+/*
+ * The Microsoft standard for printing `%e' format exponents is
+ * with a minimum of three digits, unless explicitly set otherwise,
+ * by a prior invocation of the `_set_output_format()' function.
+ *
+ * The following macro allows us to replicate this behaviour.
+ */
+# define PFORMAT_MINEXP __pformat_exponent_digits()
+ /*
+ * However, this feature is unsupported for versions of the
+ * MSVC runtime library prior to msvcr80.dll, and by default,
+ * MinGW uses an earlier version, (equivalent to msvcr60.dll),
+ * for which `_TWO_DIGIT_EXPONENT' will be undefined.
+ */
+# ifndef _TWO_DIGIT_EXPONENT
+ /*
+ * This hack works around the lack of the `_set_output_format()'
+ * feature, when supporting versions of the MSVC runtime library
+ * prior to msvcr80.dll; it simply enforces Microsoft's original
+ * convention, for all cases where the feature is unsupported.
+ */
+# define _get_output_format() 0
+# define _TWO_DIGIT_EXPONENT 1
+# endif
+/*
+ * Irrespective of the MSVCRT version supported, *we* will add
+ * an additional capability, through the following inline function,
+ * which will allow the user to choose his own preferred default
+ * for `PRINTF_EXPONENT_DIGITS', through the simple expedient
+ * of defining it as an environment variable.
+ */
+static __inline__ __attribute__((__always_inline__))
+int __pformat_exponent_digits( void )
+{
+ char *exponent_digits = getenv( "PRINTF_EXPONENT_DIGITS" );
+ return ((exponent_digits != NULL) && ((unsigned)(*exponent_digits - '0') < 3))
+ || (_get_output_format() & _TWO_DIGIT_EXPONENT)
+ ? 2
+ : 3
+ ;
+}
+#else
+/*
+ * When we don't care to mimic Microsoft's standard behaviour,
+ * we adopt the C99/POSIX standard of two digit exponents.
+ */
+# define PFORMAT_MINEXP 2
+#endif
+
+typedef union
+{
+ /* A data type agnostic representation,
+ * for printf arguments of any integral data type...
+ */
+ signed long __pformat_long_t;
+ signed long long __pformat_llong_t;
+ unsigned long __pformat_ulong_t;
+ unsigned long long __pformat_ullong_t;
+ unsigned short __pformat_ushort_t;
+ unsigned char __pformat_uchar_t;
+ signed short __pformat_short_t;
+ signed char __pformat_char_t;
+ void * __pformat_ptr_t;
+} __pformat_intarg_t;
+
+typedef enum
+{
+ /* Format interpreter state indices...
+ * (used to identify the active phase of format string parsing).
+ */
+ PFORMAT_INIT = 0,
+ PFORMAT_SET_WIDTH,
+ PFORMAT_GET_PRECISION,
+ PFORMAT_SET_PRECISION,
+ PFORMAT_END
+} __pformat_state_t;
+
+typedef enum
+{
+ /* Argument length classification indices...
+ * (used for arguments representing integer data types).
+ */
+ PFORMAT_LENGTH_INT = 0,
+ PFORMAT_LENGTH_SHORT,
+ PFORMAT_LENGTH_LONG,
+ PFORMAT_LENGTH_LLONG,
+ PFORMAT_LENGTH_CHAR
+} __pformat_length_t;
+/*
+ * And a macro to map any arbitrary data type to an appropriate
+ * matching index, selected from those above; the compiler should
+ * collapse this to a simple assignment.
+ */
+#define __pformat_arg_length( type ) \
+ sizeof( type ) == sizeof( long long ) ? PFORMAT_LENGTH_LLONG : \
+ sizeof( type ) == sizeof( long ) ? PFORMAT_LENGTH_LONG : \
+ sizeof( type ) == sizeof( short ) ? PFORMAT_LENGTH_SHORT : \
+ sizeof( type ) == sizeof( char ) ? PFORMAT_LENGTH_CHAR : \
+ /* should never need this default */ PFORMAT_LENGTH_INT
+
+typedef struct
+{
+ /* Formatting and output control data...
+ * An instance of this control block is created, (on the stack),
+ * for each call to `__pformat()', and is passed by reference to
+ * each of the output handlers, as required.
+ */
+ void * dest;
+ int flags;
+ int width;
+ int precision;
+ int rplen;
+ wchar_t rpchr;
+ int count;
+ int quota;
+ int expmin;
+} __pformat_t;
+
+static
+void __pformat_putc( int c, __pformat_t *stream )
+{
+ /* Place a single character into the `__pformat()' output queue,
+ * provided any specified output quota has not been exceeded.
+ */
+ if( (stream->flags & PFORMAT_NOLIMIT) || (stream->quota > stream->count) )
+ {
+ /* Either there was no quota specified,
+ * or the active quota has not yet been reached.
+ */
+ if( stream->flags & PFORMAT_TO_FILE )
+ /*
+ * This is single character output to a FILE stream...
+ */
+ fputc( c, (FILE *)(stream->dest) );
+
+ else
+ /* Whereas, this is to an internal memory buffer...
+ */
+ ((char *)(stream->dest))[stream->count] = c;
+ }
+ ++stream->count;
+}
+
+static
+void __pformat_putchars( const char *s, int count, __pformat_t *stream )
+{
+ /* Handler for `%c' and (indirectly) `%s' conversion specifications.
+ *
+ * Transfer characters from the string buffer at `s', character by
+ * character, up to the number of characters specified by `count', or
+ * if `precision' has been explicitly set to a value less than `count',
+ * stopping after the number of characters specified for `precision',
+ * to the `__pformat()' output stream.
+ *
+ * Characters to be emitted are passed through `__pformat_putc()', to
+ * ensure that any specified output quota is honoured.
+ */
+ if( (stream->precision >= 0) && (count > stream->precision) )
+ /*
+ * Ensure that the maximum number of characters transferred doesn't
+ * exceed any explicitly set `precision' specification.
+ */
+ count = stream->precision;
+
+ /* Establish the width of any field padding required...
+ */
+ if( stream->width > count )
+ /*
+ * as the number of spaces equivalent to the number of characters
+ * by which those to be emitted is fewer than the field width...
+ */
+ stream->width -= count;
+
+ else
+ /* ignoring any width specification which is insufficient.
+ */
+ stream->width = PFORMAT_IGNORE;
+
+ if( (stream->width > 0) && ((stream->flags & PFORMAT_LJUSTIFY) == 0) )
+ /*
+ * When not doing flush left justification, (i.e. the `-' flag
+ * is not set), any residual unreserved field width must appear
+ * as blank padding, to the left of the output string.
+ */
+ while( stream->width-- )
+ __pformat_putc( '\x20', stream );
+
+ /* Emit the data...
+ */
+ while( count-- )
+ /*
+ * copying the requisite number of characters from the input.
+ */
+ __pformat_putc( *s++, stream );
+
+ /* If we still haven't consumed the entire specified field width,
+ * we must be doing flush left justification; any residual width
+ * must be filled with blanks, to the right of the output value.
+ */
+ while( stream->width-- > 0 )
+ __pformat_putc( '\x20', stream );
+}
+
+static __inline__
+void __pformat_puts( const char *s, __pformat_t *stream )
+{
+ /* Handler for `%s' conversion specifications.
+ *
+ * Transfer a NUL terminated character string, character by character,
+ * stopping when the end of the string is encountered, or if `precision'
+ * has been explicitly set, when the specified number of characters has
+ * been emitted, if that is less than the length of the input string,
+ * to the `__pformat()' output stream.
+ *
+ * This is implemented as a trivial call to `__pformat_putchars()',
+ * passing the length of the input string as the character count,
+ * (after first verifying that the input pointer is not NULL).
+ */
+ if( s == NULL ) s = "(null)";
+ __pformat_putchars( s, strlen( s ), stream );
+}
+
+static
+void __pformat_wputchars( const wchar_t *s, int count, __pformat_t *stream )
+{
+ /* Handler for `%C'(`%lc') and `%S'(`%ls') conversion specifications;
+ * (this is a wide character variant of `__pformat_putchars()').
+ *
+ * Each multibyte character sequence to be emitted is passed, byte
+ * by byte, through `__pformat_putc()', to ensure that any specified
+ * output quota is honoured.
+ */
+ char buf[16]; mbstate_t state; int len = wcrtomb( buf, L'\0', &state );
+
+ if( (stream->precision >= 0) && (count > stream->precision) )
+ /*
+ * Ensure that the maximum number of characters transferred doesn't
+ * exceed any explicitly set `precision' specification.
+ */
+ count = stream->precision;
+
+ /* Establish the width of any field padding required...
+ */
+ if( stream->width > count )
+ /*
+ * as the number of spaces equivalent to the number of characters
+ * by which those to be emitted is fewer than the field width...
+ */
+ stream->width -= count;
+
+ else
+ /* ignoring any width specification which is insufficient.
+ */
+ stream->width = PFORMAT_IGNORE;
+
+ if( (stream->width > 0) && ((stream->flags & PFORMAT_LJUSTIFY) == 0) )
+ /*
+ * When not doing flush left justification, (i.e. the `-' flag
+ * is not set), any residual unreserved field width must appear
+ * as blank padding, to the left of the output string.
+ */
+ while( stream->width-- )
+ __pformat_putc( '\x20', stream );
+
+ /* Emit the data, converting each character from the wide
+ * to the multibyte domain as we go...
+ */
+ while( (count-- > 0) && ((len = wcrtomb( buf, *s++, &state )) > 0) )
+ {
+ char *p = buf;
+ while( len-- > 0 )
+ __pformat_putc( *p++, stream );
+ }
+
+ /* If we still haven't consumed the entire specified field width,
+ * we must be doing flush left justification; any residual width
+ * must be filled with blanks, to the right of the output value.
+ */
+ while( stream->width-- > 0 )
+ __pformat_putc( '\x20', stream );
+}
+
+static __inline__ __attribute__((__always_inline__))
+void __pformat_wcputs( const wchar_t *s, __pformat_t *stream )
+{
+ /* Handler for `%S' (`%ls') conversion specifications.
+ *
+ * Transfer a NUL terminated wide character string, character by
+ * character, converting to its equivalent multibyte representation
+ * on output, and stopping when the end of the string is encountered,
+ * or if `precision' has been explicitly set, when the specified number
+ * of characters has been emitted, if that is less than the length of
+ * the input string, to the `__pformat()' output stream.
+ *
+ * This is implemented as a trivial call to `__pformat_wputchars()',
+ * passing the length of the input string as the character count,
+ * (after first verifying that the input pointer is not NULL).
+ */
+ if( s == NULL ) s = L"(null)";
+ __pformat_wputchars( s, wcslen( s ), stream );
+}
+
+static __inline__
+int __pformat_int_bufsiz( int bias, int size, __pformat_t *stream )
+{
+ /* Helper to establish the size of the internal buffer, which
+ * is required to queue the ASCII decomposition of an integral
+ * data value, prior to transfer to the output stream.
+ */
+ size = ((size - 1 + LLONGBITS) / size) + bias;
+ size += (stream->precision > 0) ? stream->precision : 0;
+ return (size > stream->width) ? size : stream->width;
+}
+
+static
+void __pformat_int( __pformat_intarg_t value, __pformat_t *stream )
+{
+ /* Handler for `%d', `%i' and `%u' conversion specifications.
+ *
+ * Transfer the ASCII representation of an integer value parameter,
+ * formatted as a decimal number, to the `__pformat()' output queue;
+ * output will be truncated, if any specified quota is exceeded.
+ */
+ char buf[__pformat_int_bufsiz(1, PFORMAT_OSHIFT, stream)];
+ char *p = buf; int precision;
+
+ if( stream->flags & PFORMAT_NEGATIVE )
+ {
+ /* The input value might be negative, (i.e. it is a signed value)...
+ */
+ if( value.__pformat_llong_t < 0LL )
+ /*
+ * It IS negative, but we want to encode it as unsigned,
+ * displayed with a leading minus sign, so convert it...
+ */
+ value.__pformat_llong_t = -value.__pformat_llong_t;
+
+ else
+ /* It is unequivocally a POSITIVE value, so turn off the
+ * request to prefix it with a minus sign...
+ */
+ stream->flags &= ~PFORMAT_NEGATIVE;
+ }
+
+ /* Encode the input value for display...
+ */
+ while( value.__pformat_ullong_t )
+ {
+ /* decomposing it into its constituent decimal digits,
+ * in order from least significant to most significant, using
+ * the local buffer as a LIFO queue in which to store them.
+ */
+ *p++ = '0' + (unsigned char)(value.__pformat_ullong_t % 10LL);
+ value.__pformat_ullong_t /= 10LL;
+ }
+
+ if( (stream->precision > 0)
+ && ((precision = stream->precision - (p - buf)) > 0) )
+ /*
+ * We have not yet queued sufficient digits to fill the field width
+ * specified for minimum `precision'; pad with zeros to achieve this.
+ */
+ while( precision-- > 0 )
+ *p++ = '0';
+
+ if( (p == buf) && (stream->precision != 0) )
+ /*
+ * Input value was zero; make sure we print at least one digit,
+ * unless the precision is also explicitly zero.
+ */
+ *p++ = '0';
+
+ if( (stream->width > 0) && ((stream->width -= p - buf) > 0) )
+ {
+ /* We have now queued sufficient characters to display the input value,
+ * at the desired precision, but this will not fill the output field...
+ */
+ if( stream->flags & PFORMAT_SIGNED )
+ /*
+ * We will fill one additional space with a sign...
+ */
+ stream->width--;
+
+ if( (stream->precision < 0)
+ && ((stream->flags & PFORMAT_JUSTIFY) == PFORMAT_ZEROFILL) )
+ /*
+ * and the `0' flag is in effect, so we pad the remaining spaces,
+ * to the left of the displayed value, with zeros.
+ */
+ while( stream->width-- > 0 )
+ *p++ = '0';
+
+ else if( (stream->flags & PFORMAT_LJUSTIFY) == 0 )
+ /*
+ * the `0' flag is not in effect, and neither is the `-' flag,
+ * so we pad to the left of the displayed value with spaces, so that
+ * the value appears right justified within the output field.
+ */
+ while( stream->width-- > 0 )
+ __pformat_putc( '\x20', stream );
+ }
+
+ if( stream->flags & PFORMAT_NEGATIVE )
+ /*
+ * A negative value needs a sign...
+ */
+ *p++ = '-';
+
+ else if( stream->flags & PFORMAT_POSITIVE )
+ /*
+ * A positive value may have an optionally displayed sign...
+ */
+ *p++ = '+';
+
+ else if( stream->flags & PFORMAT_ADDSPACE )
+ /*
+ * Space was reserved for displaying a sign, but none was emitted...
+ */
+ *p++ = '\x20';
+
+ while( p > buf )
+ /*
+ * Emit the accumulated constituent digits,
+ * in order from most significant to least significant...
+ */
+ __pformat_putc( *--p, stream );
+
+ while( stream->width-- > 0 )
+ /*
+ * The specified output field has not yet been completely filled;
+ * the `-' flag must be in effect, resulting in a displayed value which
+ * appears left justified within the output field; we must pad the field
+ * to the right of the displayed value, by emitting additional spaces,
+ * until we reach the rightmost field boundary.
+ */
+ __pformat_putc( '\x20', stream );
+}
+
+static
+void __pformat_xint( int fmt, __pformat_intarg_t value, __pformat_t *stream )
+{
+ /* Handler for `%o', `%p', `%x' and `%X' conversions.
+ *
+ * These can be implemented using a simple `mask and shift' strategy;
+ * set up the mask and shift values appropriate to the conversion format,
+ * and allocate a suitably sized local buffer, in which to queue encoded
+ * digits of the formatted value, in preparation for output.
+ */
+ int width;
+ int mask = (fmt == 'o') ? PFORMAT_OMASK : PFORMAT_XMASK;
+ int shift = (fmt == 'o') ? PFORMAT_OSHIFT : PFORMAT_XSHIFT;
+ char buf[__pformat_int_bufsiz(2, shift, stream)];
+ char *p = buf;
+
+ while( value.__pformat_ullong_t )
+ {
+ /* Encode the specified non-zero input value as a sequence of digits,
+ * in the appropriate `base' encoding and in reverse digit order, each
+ * encoded in its printable ASCII form, with no leading zeros, using
+ * the local buffer as a LIFO queue in which to store them.
+ */
+ char *q;
+ if( (*(q = p++) = '0' + (value.__pformat_ullong_t & mask)) > '9' )
+ *q = (*q + 'A' - '9' - 1) | (fmt & PFORMAT_XCASE);
+ value.__pformat_ullong_t >>= shift;
+ }
+
+ if( p == buf )
+ /*
+ * Nothing was queued; input value must be zero, which should never be
+ * emitted in the `alternative' PFORMAT_HASHED style.
+ */
+ stream->flags &= ~PFORMAT_HASHED;
+
+ if( ((width = stream->precision) > 0) && ((width -= p - buf) > 0) )
+ /*
+ * We have not yet queued sufficient digits to fill the field width
+ * specified for minimum `precision'; pad with zeros to achieve this.
+ */
+ while( width-- > 0 )
+ *p++ = '0';
+
+ else if( (fmt == 'o') && (stream->flags & PFORMAT_HASHED) )
+ /*
+ * The field width specified for minimum `precision' has already
+ * been filled, but the `alternative' PFORMAT_HASHED style for octal
+ * output requires at least one initial zero; that will not have
+ * been queued, so add it now.
+ */
+ *p++ = '0';
+
+ if( (p == buf) && (stream->precision != 0) )
+ /*
+ * Still nothing queued for output, but the `precision' has not been
+ * explicitly specified as zero, (which is necessary if no output for
+ * an input value of zero is desired); queue exactly one zero digit.
+ */
+ *p++ = '0';
+
+ if( stream->width > (width = p - buf) )
+ /*
+ * Specified field width exceeds the minimum required...
+ * Adjust so that we retain only the additional padding width.
+ */
+ stream->width -= width;
+
+ else
+ /* Ignore any width specification which is insufficient.
+ */
+ stream->width = PFORMAT_IGNORE;
+
+ if( ((width = stream->width) > 0)
+ && (fmt != 'o') && (stream->flags & PFORMAT_HASHED) )
+ /*
+ * For `%#x' or `%#X' formats, (which have the `#' flag set),
+ * further reduce the padding width to accommodate the radix
+ * indicating prefix.
+ */
+ width -= 2;
+
+ if( (width > 0) && (stream->precision < 0)
+ && ((stream->flags & PFORMAT_JUSTIFY) == PFORMAT_ZEROFILL) )
+ /*
+ * When the `0' flag is set, and not overridden by the `-' flag,
+ * or by a specified precision, add sufficient leading zeros to
+ * consume the remaining field width.
+ */
+ while( width-- > 0 )
+ *p++ = '0';
+
+ if( (fmt != 'o') && (stream->flags & PFORMAT_HASHED) )
+ {
+ /* For formats other than octal, the PFORMAT_HASHED output style
+ * requires the addition of a two character radix indicator, as a
+ * prefix to the actual encoded numeric value.
+ */
+ *p++ = fmt;
+ *p++ = '0';
+ }
+
+ if( (width > 0) && ((stream->flags & PFORMAT_LJUSTIFY) == 0) )
+ /*
+ * When not doing flush left justification, (i.e. the `-' flag
+ * is not set), any residual unreserved field width must appear
+ * as blank padding, to the left of the output value.
+ */
+ while( width-- > 0 )
+ __pformat_putc( '\x20', stream );
+
+ while( p > buf )
+ /*
+ * Move the queued output from the local buffer to the ultimate
+ * destination, in LIFO order.
+ */
+ __pformat_putc( *--p, stream );
+
+ /* If we still haven't consumed the entire specified field width,
+ * we must be doing flush left justification; any residual width
+ * must be filled with blanks, to the right of the output value.
+ */
+ while( width-- > 0 )
+ __pformat_putc( '\x20', stream );
+}
+
+typedef union
+{
+ /* A multifaceted representation of an IEEE extended precision,
+ * (80-bit), floating point number, facilitating access to its
+ * component parts.
+ */
+ double __pformat_fpreg_double_t;
+ long double __pformat_fpreg_ldouble_t;
+ struct
+ { unsigned long long __pformat_fpreg_mantissa;
+ signed short __pformat_fpreg_exponent;
+ };
+ unsigned short __pformat_fpreg_bitmap[5];
+ unsigned long __pformat_fpreg_bits;
+} __pformat_fpreg_t;
+
+#ifdef _WIN32
+/* TODO: make this unconditional in final release...
+ * (see note at head of associated `#else' block.
+ */
+#include "gdtoa.h"
+
+static
+char *__pformat_cvt( int mode, __pformat_fpreg_t x, int nd, int *dp, int *sign )
+{
+ /* Helper function, derived from David M. Gay's `g_xfmt()', calling
+ * his `__gdtoa()' function in a manner to provide extended precision
+ * replacements for `ecvt()' and `fcvt()'.
+ */
+ int k; unsigned int e = 0; char *ep;
+ static FPI fpi = { 64, 1-16383-64+1, 32766-16383-64+1, FPI_Round_near, 0 };
+
+ /* Classify the argument into an appropriate `__gdtoa()' category...
+ */
+ if( (k = __fpclassifyl( x.__pformat_fpreg_ldouble_t )) & FP_NAN )
+ /*
+ * identifying infinities or not-a-number...
+ */
+ k = (k & FP_NORMAL) ? STRTOG_Infinite : STRTOG_NaN;
+
+ else if( k & FP_NORMAL )
+ {
+ /* normal and near-zero `denormals'...
+ */
+ if( k & FP_ZERO )
+ {
+ /* with appropriate exponent adjustment for a `denormal'...
+ */
+ k = STRTOG_Denormal;
+ e = 1 - 0x3FFF - 63;
+ }
+ else
+ {
+ /* or with `normal' exponent adjustment...
+ */
+ k = STRTOG_Normal;
+ e = (x.__pformat_fpreg_exponent & 0x7FFF) - 0x3FFF - 63;
+ }
+ }
+
+ else
+ /* or, if none of the above, it's a zero, (positive or negative).
+ */
+ k = STRTOG_Zero;
+
+ /* Check for negative values, always treating NaN as unsigned...
+ * (return value is zero for positive/unsigned; non-zero for negative).
+ */
+ *sign = (k == STRTOG_NaN) ? 0 : x.__pformat_fpreg_exponent & 0x8000;
+
+ /* Finally, get the raw digit string, and radix point position index.
+ */
+ return __gdtoa( &fpi, e, &x.__pformat_fpreg_bits, &k, mode, nd, dp, &ep );
+}
+
+static __inline__ __attribute__((__always_inline__))
+char *__pformat_ecvt( long double x, int precision, int *dp, int *sign )
+{
+ /* A convenience wrapper for the above...
+ * it emulates `ecvt()', but takes a `long double' argument.
+ */
+ __pformat_fpreg_t z; z.__pformat_fpreg_ldouble_t = x;
+ return __pformat_cvt( 2, z, precision, dp, sign );
+}
+
+static __inline__ __attribute__((__always_inline__))
+char *__pformat_fcvt( long double x, int precision, int *dp, int *sign )
+{
+ /* A convenience wrapper for the above...
+ * it emulates `fcvt()', but takes a `long double' argument.
+ */
+ __pformat_fpreg_t z; z.__pformat_fpreg_ldouble_t = x;
+ return __pformat_cvt( 3, z, precision, dp, sign );
+}
+
+/* The following are required, to clean up the `__gdtoa()' memory pool,
+ * after processing the data returned by the above.
+ */
+#define __pformat_ecvt_release( value ) __freedtoa( value )
+#define __pformat_fcvt_release( value ) __freedtoa( value )
+
+#else
+/*
+ * TODO: remove this before final release; it is included here as a
+ * convenience for testing, without requiring a working `__gdtoa()'.
+ */
+static __inline__
+char *__pformat_ecvt( long double x, int precision, int *dp, int *sign )
+{
+ /* Define in terms of `ecvt()'...
+ */
+ char *retval = ecvt( (double)(x), precision, dp, sign );
+ if( isinf( x ) || isnan( x ) )
+ {
+ /* emulating `__gdtoa()' reporting for infinities and NaN.
+ */
+ *dp = PFORMAT_INFNAN;
+ if( *retval == '-' )
+ {
+ /* Need to force the `sign' flag, (particularly for NaN).
+ */
+ ++retval; *sign = 1;
+ }
+ }
+ return retval;
+}
+
+static __inline__
+char *__pformat_fcvt( long double x, int precision, int *dp, int *sign )
+{
+ /* Define in terms of `fcvt()'...
+ */
+ char *retval = fcvt( (double)(x), precision, dp, sign );
+ if( isinf( x ) || isnan( x ) )
+ {
+ /* emulating `__gdtoa()' reporting for infinities and NaN.
+ */
+ *dp = PFORMAT_INFNAN;
+ if( *retval == '-' )
+ {
+ /* Need to force the `sign' flag, (particularly for NaN).
+ */
+ ++retval; *sign = 1;
+ }
+ }
+ return retval;
+}
+
+/* No memory pool clean up needed, for these emulated cases...
+ */
+#define __pformat_ecvt_release( value ) /* nothing to be done */
+#define __pformat_fcvt_release( value ) /* nothing to be done */
+
+/* TODO: end of conditional to be removed. */
+#endif
+
+static __inline__
+void __pformat_emit_radix_point( __pformat_t *stream )
+{
+ /* Helper to place a localised representation of the radix point
+ * character at the ultimate destination, when formatting fixed or
+ * floating point numbers.
+ */
+ if( stream->rplen == PFORMAT_RPINIT )
+ {
+ /* Radix point initialisation not yet completed;
+ * establish a multibyte to `wchar_t' converter...
+ */
+ int len; wchar_t rpchr; mbstate_t state;
+
+ /* Initialise the conversion state...
+ */
+ memset( &state, 0, sizeof( state ) );
+
+ /* Fetch and convert the localised radix point representation...
+ */
+ if( (len = mbrtowc( &rpchr, localeconv()->decimal_point, 16, &state )) > 0 )
+ /*
+ * and store it, if valid.
+ */
+ stream->rpchr = rpchr;
+
+ /* In any case, store the reported effective multibyte length,
+ * (or the error flag), marking initialisation as `done'.
+ */
+ stream->rplen = len;
+ }
+
+ if( stream->rpchr != (wchar_t)(0) )
+ {
+ /* We have a localised radix point mark;
+ * establish a converter to make it a multibyte character...
+ */
+ int len; char buf[len = stream->rplen]; mbstate_t state;
+
+ /* Initialise the conversion state...
+ */
+ memset( &state, 0, sizeof( state ) );
+
+ /* Convert the `wchar_t' representation to multibyte...
+ */
+ if( (len = wcrtomb( buf, stream->rpchr, &state )) > 0 )
+ {
+ /* and copy to the output destination, when valid...
+ */
+ char *p = buf;
+ while( len-- > 0 )
+ __pformat_putc( *p++, stream );
+ }
+
+ else
+ /* otherwise fall back to plain ASCII '.'...
+ */
+ __pformat_putc( '.', stream );
+ }
+
+ else
+ /* No localisation: just use ASCII '.'...
+ */
+ __pformat_putc( '.', stream );
+}
+
+static __inline__ __attribute__((__always_inline__))
+void __pformat_emit_numeric_value( int c, __pformat_t *stream )
+{
+ /* Convenience helper to transfer numeric data from an internal
+ * formatting buffer to the ultimate destination...
+ */
+ if( c == '.' )
+ /*
+ * converting this internal representation of the the radix
+ * point to the appropriately localised representation...
+ */
+ __pformat_emit_radix_point( stream );
+
+ else
+ /* and passing all other characters through, unmodified.
+ */
+ __pformat_putc( c, stream );
+}
+
+static
+void __pformat_emit_inf_or_nan( int sign, char *value, __pformat_t *stream )
+{
+ /* Helper to emit INF or NAN where a floating point value
+ * resolves to one of these special states.
+ */
+ int i;
+ char buf[4];
+ char *p = buf;
+
+ /* We use the string formatting helper to display INF/NAN,
+ * but we don't want truncation if the precision set for the
+ * original floating point output request was insufficient;
+ * ignore it!
+ */
+ stream->precision = PFORMAT_IGNORE;
+
+ if( sign )
+ /*
+ * Negative infinity: emit the sign...
+ */
+ *p++ = '-';
+
+ else if( stream->flags & PFORMAT_POSITIVE )
+ /*
+ * Not negative infinity, but '+' flag is in effect;
+ * thus, we emit a positive sign...
+ */
+ *p++ = '+';
+
+ else if( stream->flags & PFORMAT_ADDSPACE )
+ /*
+ * No sign required, but space was reserved for it...
+ */
+ *p++ = '\x20';
+
+ /* Copy the appropriate status indicator, up to a maximum of
+ * three characters, transforming to the case corresponding to
+ * the format specification...
+ */
+ for( i = 3; i > 0; --i )
+ *p++ = (*value++ & ~PFORMAT_XCASE) | (stream->flags & PFORMAT_XCASE);
+
+ /* and emit the result.
+ */
+ __pformat_putchars( buf, p - buf, stream );
+}
+
+static
+void __pformat_emit_float( int sign, char *value, int len, __pformat_t *stream )
+{
+ /* Helper to emit a fixed point representation of numeric data,
+ * as encoded by a prior call to `ecvt()' or `fcvt()'; (this does
+ * NOT include the exponent, for floating point format).
+ */
+ if( len > 0 )
+ {
+ /* The magnitude of `x' is greater than or equal to 1.0...
+ * reserve space in the output field, for the required number of
+ * decimal digits to be placed before the decimal point...
+ */
+ if( stream->width > len )
+ /*
+ * adjusting as appropriate, when width is sufficient...
+ */
+ stream->width -= len;
+
+ else
+ /* or simply ignoring the width specification, if not.
+ */
+ stream->width = PFORMAT_IGNORE;
+ }
+
+ else if( stream->width > 0 )
+ /*
+ * The magnitude of `x' is less than 1.0...
+ * reserve space for exactly one zero before the decimal point.
+ */
+ stream->width--;
+
+ /* Reserve additional space for the digits which will follow the
+ * decimal point...
+ */
+ if( (stream->width >= 0) && (stream->width > stream->precision) )
+ /*
+ * adjusting appropriately, when sufficient width remains...
+ * (note that we must check both of these conditions, because
+ * precision may be more negative than width, as a result of
+ * adjustment to provide extra padding when trailing zeros
+ * are to be discarded from "%g" format conversion with a
+ * specified field width, but if width itself is negative,
+ * then there is explicitly to be no padding anyway).
+ */
+ stream->width -= stream->precision;
+
+ else
+ /* or again, ignoring the width specification, if not.
+ */
+ stream->width = PFORMAT_IGNORE;
+
+ /* Reserve space in the output field, for display of the decimal point,
+ * unless the precision is explicity zero, with the `#' flag not set.
+ */
+ if( (stream->width > 0)
+ && ((stream->precision > 0) || (stream->flags & PFORMAT_HASHED)) )
+ stream->width--;
+
+ /* Reserve space in the output field, for display of the sign of the
+ * formatted value, if required; (i.e. if the value is negative, or if
+ * either the `space' or `+' formatting flags are set).
+ */
+ if( (stream->width > 0) && (sign || (stream->flags & PFORMAT_SIGNED)) )
+ stream->width--;
+
+ /* Emit any padding space, as required to correctly right justify
+ * the output within the alloted field width.
+ */
+ if( (stream->width > 0) && ((stream->flags & PFORMAT_JUSTIFY) == 0) )
+ while( stream->width-- > 0 )
+ __pformat_putc( '\x20', stream );
+
+ /* Emit the sign indicator, as appropriate...
+ */
+ if( sign )
+ /*
+ * mandatory, for negative values...
+ */
+ __pformat_putc( '-', stream );
+
+ else if( stream->flags & PFORMAT_POSITIVE )
+ /*
+ * optional, for positive values...
+ */
+ __pformat_putc( '+', stream );
+
+ else if( stream->flags & PFORMAT_ADDSPACE )
+ /*
+ * or just fill reserved space, when the space flag is in effect.
+ */
+ __pformat_putc( '\x20', stream );
+
+ /* If the `0' flag is in effect, and not overridden by the `-' flag,
+ * then zero padding, to fill out the field, goes here...
+ */
+ if( (stream->width > 0)
+ && ((stream->flags & PFORMAT_JUSTIFY) == PFORMAT_ZEROFILL) )
+ while( stream->width-- > 0 )
+ __pformat_putc( '0', stream );
+
+ /* Emit the digits of the encoded numeric value...
+ */
+ if( len > 0 )
+ /*
+ * ...beginning with those which precede the radix point,
+ * and appending any necessary significant trailing zeros.
+ */
+ do __pformat_putc( *value ? *value++ : '0', stream );
+ while( --len > 0 );
+
+ else
+ /* The magnitude of the encoded value is less than 1.0, so no
+ * digits precede the radix point; we emit a mandatory initial
+ * zero, followed immediately by the radix point.
+ */
+ __pformat_putc( '0', stream );
+
+ /* Unless the encoded value is integral, AND the radix point
+ * is not expressly demanded by the `#' flag, we must insert
+ * the appropriately localised radix point mark here...
+ */
+ if( (stream->precision > 0) || (stream->flags & PFORMAT_HASHED) )
+ __pformat_emit_radix_point( stream );
+
+ /* When the radix point offset, `len', is negative, this implies
+ * that additional zeros must appear, following the radix point,
+ * and preceding the first significant digit...
+ */
+ if( len < 0 )
+ {
+ /* To accommodate these, we adjust the precision, (reducing it
+ * by adding a negative value), and then we emit as many zeros
+ * as are required.
+ */
+ stream->precision += len;
+ do __pformat_putc( '0', stream );
+ while( ++len < 0 );
+ }
+
+ /* Now we emit any remaining significant digits, or trailing zeros,
+ * until the required precision has been achieved.
+ */
+ while( stream->precision-- > 0 )
+ __pformat_putc( *value ? *value++ : '0', stream );
+}
+
+static
+void __pformat_emit_efloat( int sign, char *value, int e, __pformat_t *stream )
+{
+ /* Helper to emit a floating point representation of numeric data,
+ * as encoded by a prior call to `ecvt()' or `fcvt()'; (this DOES
+ * include the following exponent).
+ */
+ int exp_width = 1;
+ __pformat_intarg_t exponent; exponent.__pformat_llong_t = e -= 1;
+
+ /* Determine how many digit positions are required for the exponent.
+ */
+ while( (e /= 10) != 0 )
+ exp_width++;
+
+ /* Ensure that this is at least as many as the standard requirement.
+ */
+ if( exp_width < stream->expmin )
+ exp_width = stream->expmin;
+
+ /* Adjust the residual field width allocation, to allow for the
+ * number of exponent digits to be emitted, together with a sign
+ * and exponent separator...
+ */
+ if( stream->width > (exp_width += 2) )
+ stream->width -= exp_width;
+
+ else
+ /* ignoring the field width specification, if insufficient.
+ */
+ stream->width = PFORMAT_IGNORE;
+
+ /* Emit the significand, as a fixed point value with one digit
+ * preceding the radix point.
+ */
+ __pformat_emit_float( sign, value, 1, stream );
+
+ /* Reset precision, to ensure the mandatory minimum number of
+ * exponent digits will be emitted, and set the flags to ensure
+ * the sign is displayed.
+ */
+ stream->precision = stream->expmin;
+ stream->flags |= PFORMAT_SIGNED;
+
+ /* Emit the exponent separator.
+ */
+ __pformat_putc( ('E' | (stream->flags & PFORMAT_XCASE)), stream );
+
+ /* Readjust the field width setting, such that it again allows
+ * for the digits of the exponent, (which had been discounted when
+ * computing any left side padding requirement), so that they are
+ * correctly included in the computation of any right side padding
+ * requirement, (but here we exclude the exponent separator, which
+ * has been emitted, and so counted already).
+ */
+ stream->width += exp_width - 1;
+
+ /* And finally, emit the exponent itself, as a signed integer,
+ * with any padding required to achieve flush left justification,
+ * (which will be added automatically, by `__pformat_int()').
+ */
+ __pformat_int( exponent, stream );
+}
+
+static
+void __pformat_float( long double x, __pformat_t *stream )
+{
+ /* Handler for `%f' and `%F' format specifiers.
+ *
+ * This wraps calls to `__pformat_cvt()', `__pformat_emit_float()'
+ * and `__pformat_emit_inf_or_nan()', as appropriate, to achieve
+ * output in fixed point format.
+ */
+ int sign, intlen; char *value;
+
+ /* Establish the precision for the displayed value, defaulting to six
+ * digits following the decimal point, if not explicitly specified.
+ */
+ if( stream->precision < 0 )
+ stream->precision = 6;
+
+ /* Encode the input value as ASCII, for display...
+ */
+ value = __pformat_fcvt( x, stream->precision, &intlen, &sign );
+
+ if( intlen == PFORMAT_INFNAN )
+ /*
+ * handle cases of `infinity' or `not-a-number'...
+ */
+ __pformat_emit_inf_or_nan( sign, value, stream );
+
+ else
+ { /* or otherwise, emit the formatted result.
+ */
+ __pformat_emit_float( sign, value, intlen, stream );
+
+ /* and, if there is any residual field width as yet unfilled,
+ * then we must be doing flush left justification, so pad out to
+ * the right hand field boundary.
+ */
+ while( stream->width-- > 0 )
+ __pformat_putc( '\x20', stream );
+ }
+
+ /* Clean up `__pformat_fcvt()' memory allocation for `value'...
+ */
+ __pformat_fcvt_release( value );
+}
+
+static
+void __pformat_efloat( long double x, __pformat_t *stream )
+{
+ /* Handler for `%e' and `%E' format specifiers.
+ *
+ * This wraps calls to `__pformat_cvt()', `__pformat_emit_efloat()'
+ * and `__pformat_emit_inf_or_nan()', as appropriate, to achieve
+ * output in floating point format.
+ */
+ int sign, intlen; char *value;
+
+ /* Establish the precision for the displayed value, defaulting to six
+ * digits following the decimal point, if not explicitly specified.
+ */
+ if( stream->precision < 0 )
+ stream->precision = 6;
+
+ /* Encode the input value as ASCII, for display...
+ */
+ value = __pformat_ecvt( x, stream->precision + 1, &intlen, &sign );
+
+ if( intlen == PFORMAT_INFNAN )
+ /*
+ * handle cases of `infinity' or `not-a-number'...
+ */
+ __pformat_emit_inf_or_nan( sign, value, stream );
+
+ else
+ /* or otherwise, emit the formatted result.
+ */
+ __pformat_emit_efloat( sign, value, intlen, stream );
+
+ /* Clean up `__pformat_ecvt()' memory allocation for `value'...
+ */
+ __pformat_ecvt_release( value );
+}
+
+static
+void __pformat_gfloat( long double x, __pformat_t *stream )
+{
+ /* Handler for `%g' and `%G' format specifiers.
+ *
+ * This wraps calls to `__pformat_cvt()', `__pformat_emit_float()',
+ * `__pformat_emit_efloat()' and `__pformat_emit_inf_or_nan()', as
+ * appropriate, to achieve output in the more suitable of either
+ * fixed or floating point format.
+ */
+ int sign, intlen; char *value;
+
+ /* Establish the precision for the displayed value, defaulting to
+ * six significant digits, if not explicitly specified...
+ */
+ if( stream->precision < 0 )
+ stream->precision = 6;
+
+ /* or to a minimum of one digit, otherwise...
+ */
+ else if( stream->precision == 0 )
+ stream->precision = 1;
+
+ /* Encode the input value as ASCII, for display.
+ */
+ value = __pformat_ecvt( x, stream->precision, &intlen, &sign );
+
+ if( intlen == PFORMAT_INFNAN )
+ /*
+ * Handle cases of `infinity' or `not-a-number'.
+ */
+ __pformat_emit_inf_or_nan( sign, value, stream );
+
+ else if( (-4 < intlen) && (intlen <= stream->precision) )
+ {
+ /* Value lies in the acceptable range for fixed point output,
+ * (i.e. the exponent is no less than minus four, and the number
+ * of significant digits which precede the radix point is fewer
+ * than the least number which would overflow the field width,
+ * specified or implied by the established precision).
+ */
+ if( (stream->flags & PFORMAT_HASHED) == PFORMAT_HASHED )
+ /*
+ * The `#' flag is in effect...
+ * Adjust precision to retain the specified number of significant
+ * digits, with the proper number preceding the radix point, and
+ * the balance following it...
+ */
+ stream->precision -= intlen;
+
+ else
+ /* The `#' flag is not in effect...
+ * Here we adjust the precision to accommodate all digits which
+ * precede the radix point, but we truncate any balance following
+ * it, to suppress output of non-significant trailing zeros...
+ */
+ if( ((stream->precision = strlen( value ) - intlen) < 0)
+ /*
+ * This may require a compensating adjustment to the field
+ * width, to accommodate significant trailing zeros, which
+ * precede the radix point...
+ */
+ && (stream->width > 0) )
+ stream->width += stream->precision;
+
+ /* Now, we format the result as any other fixed point value.
+ */
+ __pformat_emit_float( sign, value, intlen, stream );
+
+ /* If there is any residual field width as yet unfilled, then
+ * we must be doing flush left justification, so pad out to the
+ * right hand field boundary.
+ */
+ while( stream->width-- > 0 )
+ __pformat_putc( '\x20', stream );
+ }
+
+ else
+ { /* Value lies outside the acceptable range for fixed point;
+ * one significant digit will precede the radix point, so we
+ * decrement the precision to retain only the appropriate number
+ * of additional digits following it, when we emit the result
+ * in floating point format.
+ */
+ if( (stream->flags & PFORMAT_HASHED) == PFORMAT_HASHED )
+ /*
+ * The `#' flag is in effect...
+ * Adjust precision to emit the specified number of significant
+ * digits, with one preceding the radix point, and the balance
+ * following it, retaining any non-significant trailing zeros
+ * which are required to exactly match the requested precision...
+ */
+ stream->precision--;
+
+ else
+ /* The `#' flag is not in effect...
+ * Adjust precision to emit only significant digits, with one
+ * preceding the radix point, and any others following it, but
+ * suppressing non-significant trailing zeros...
+ */
+ stream->precision = strlen( value ) - 1;
+
+ /* Now, we format the result as any other floating point value.
+ */
+ __pformat_emit_efloat( sign, value, intlen, stream );
+ }
+
+ /* Clean up `__pformat_ecvt()' memory allocation for `value'.
+ */
+ __pformat_ecvt_release( value );
+}
+
+static
+void __pformat_emit_xfloat( __pformat_fpreg_t value, __pformat_t *stream )
+{
+ /* Helper for emitting floating point data, originating as
+ * either `double' or `long double' type, as a hexadecimal
+ * representation of the argument value.
+ */
+ char buf[18], *p = buf;
+ __pformat_intarg_t exponent; short exp_width = 2;
+
+ /* The mantissa field of the argument value representation can
+ * accommodate at most 16 hexadecimal digits, of which one will
+ * be placed before the radix point, leaving at most 15 digits
+ * to satisfy any requested precision; thus...
+ */
+ if( (stream->precision >= 0) && (stream->precision < 15) )
+ {
+ /* When the user specifies a precision within this range,
+ * we want to adjust the mantissa, to retain just the number
+ * of digits required, rounding up when the high bit of the
+ * leftmost discarded digit is set; (mask of 0x08 accounts
+ * for exactly one digit discarded, shifting 4 bits per
+ * digit, with up to 14 additional digits, to consume the
+ * full availability of 15 precision digits).
+ *
+ * However, before we perform the rounding operation, we
+ * normalise the mantissa, shifting it to the left by as many
+ * bit positions may be necessary, until its highest order bit
+ * is set, thus preserving the maximum number of bits in the
+ * rounded result as possible.
+ */
+ while( value.__pformat_fpreg_mantissa < (LLONG_MAX + 1ULL) )
+ value.__pformat_fpreg_mantissa <<= 1;
+
+ /* We then shift the mantissa one bit position back to the
+ * right, to guard against possible overflow when the rounding
+ * adjustment is added.
+ */
+ value.__pformat_fpreg_mantissa >>= 1;
+
+ /* We now add the rounding adjustment, noting that to keep the
+ * 0x08 mask aligned with the shifted mantissa, we also need to
+ * shift it right by one bit initially, changing its starting
+ * value to 0x04...
+ */
+ value.__pformat_fpreg_mantissa += 0x04LL << (4 * (14 - stream->precision));
+ if( (value.__pformat_fpreg_mantissa & (LLONG_MAX + 1ULL)) == 0ULL )
+ /*
+ * When the rounding adjustment would not have overflowed,
+ * then we shift back to the left again, to fill the vacated
+ * bit we reserved to accommodate the carry.
+ */
+ value.__pformat_fpreg_mantissa <<= 1;
+
+ else
+ /* Otherwise the rounding adjustment would have overflowed,
+ * so the carry has already filled the vacated bit; the effect
+ * of this is equivalent to an increment of the exponent.
+ */
+ value.__pformat_fpreg_exponent++;
+
+ /* We now complete the rounding to the required precision, by
+ * shifting the unwanted digits out, from the right hand end of
+ * the mantissa.
+ */
+ value.__pformat_fpreg_mantissa >>= 4 * (15 - stream->precision);
+ }
+
+ /* Encode the significant digits of the mantissa in hexadecimal
+ * ASCII notation, ready for transfer to the output stream...
+ */
+ while( value.__pformat_fpreg_mantissa )
+ {
+ /* taking the rightmost digit in each pass...
+ */
+ int c = value.__pformat_fpreg_mantissa & 0xF;
+ if( c == value.__pformat_fpreg_mantissa )
+ {
+ /* inserting the radix point, when we reach the last,
+ * (i.e. the most significant digit), unless we found no
+ * less significant digits, with no mandatory radix point
+ * inclusion, and no additional required precision...
+ */
+ if( (p > buf)
+ || (stream->flags & PFORMAT_HASHED) || (stream->precision > 0) )
+ /*
+ * Internally, we represent the radix point as an ASCII '.';
+ * we will replace it with any locale specific alternative,
+ * at the time of transfer to the ultimate destination.
+ */
+ *p++ = '.';
+
+ /* If the most significant hexadecimal digit of the encoded
+ * output value is greater than one, then the indicated value
+ * will appear too large, by an additional binary exponent
+ * corresponding to the number of higher order bit positions
+ * which it occupies...
+ */
+ while( value.__pformat_fpreg_mantissa > 1 )
+ {
+ /* so reduce the exponent value to compensate...
+ */
+ value.__pformat_fpreg_exponent--;
+ value.__pformat_fpreg_mantissa >>= 1;
+ }
+ }
+
+ else if( stream->precision > 0 )
+ /*
+ * we have not yet fulfilled the desired precision,
+ * and we have not yet found the most significant digit,
+ * so account for the current digit, within the field
+ * width required to meet the specified precision.
+ */
+ stream->precision--;
+
+ if( (c > 0) || (p > buf) || (stream->precision >= 0) )
+ /*
+ * Ignoring insignificant trailing zeros, (unless required to
+ * satisfy specified precision), store the current encoded digit
+ * into the pending output buffer, in LIFO order, and using the
+ * appropriate case for digits in the `A'..`F' range.
+ */
+ *p++ = c > 9 ? (c - 10 + 'A') | (stream->flags & PFORMAT_XCASE) : c + '0';
+
+ /* Shift out the current digit, (4-bit logical shift right),
+ * to align the next more significant digit to be extracted,
+ * and encoded in the next pass.
+ */
+ value.__pformat_fpreg_mantissa >>= 4;
+ }
+
+ if( p == buf )
+ {
+ /* Nothing has been queued for output...
+ * We need at least one zero, and possibly a radix point.
+ */
+ if( (stream->precision > 0) || (stream->flags & PFORMAT_HASHED) )
+ *p++ = '.';
+
+ *p++ = '0';
+ }
+
+ if( stream->width > 0 )
+ {
+ /* Adjust the user specified field width, to account for the
+ * number of digits minimally required, to display the encoded
+ * value, at the requested precision.
+ *
+ * FIXME: this uses the minimum number of digits possible for
+ * representation of the binary exponent, in strict conformance
+ * with C99 and POSIX specifications. Although there appears to
+ * be no Microsoft precedent for doing otherwise, we may wish to
+ * relate this to the `_get_output_format()' result, to maintain
+ * consistency with `%e', `%f' and `%g' styles.
+ */
+ int min_width = p - buf;
+ int exponent = value.__pformat_fpreg_exponent;
+
+ /* If we have not yet queued sufficient digits to fulfil the
+ * requested precision, then we must adjust the minimum width
+ * specification, to accommodate the additional digits which
+ * are required to do so.
+ */
+ if( stream->precision > 0 )
+ min_width += stream->precision;
+
+ /* Adjust the minimum width requirement, to accomodate the
+ * sign, radix indicator and at least one exponent digit...
+ */
+ min_width += stream->flags & PFORMAT_SIGNED ? 6 : 5;
+ while( (exponent = exponent / 10) != 0 )
+ {
+ /* and increase as required, if additional exponent digits
+ * are needed, also saving the exponent field width adjustment,
+ * for later use when that is emitted.
+ */
+ min_width++;
+ exp_width++;
+ }
+
+ if( stream->width > min_width )
+ {
+ /* When specified field width exceeds the minimum required,
+ * adjust to retain only the excess...
+ */
+ stream->width -= min_width;
+
+ /* and then emit any required left side padding spaces.
+ */
+ if( (stream->flags & PFORMAT_JUSTIFY) == 0 )
+ while( stream->width-- > 0 )
+ __pformat_putc( '\x20', stream );
+ }
+
+ else
+ /* Specified field width is insufficient; just ignore it!
+ */
+ stream->width = PFORMAT_IGNORE;
+ }
+
+ /* Emit the sign of the encoded value, as required...
+ */
+ if( stream->flags & PFORMAT_NEGATIVE )
+ /*
+ * this is mandatory, to indicate a negative value...
+ */
+ __pformat_putc( '-', stream );
+
+ else if( stream->flags & PFORMAT_POSITIVE )
+ /*
+ * but this is optional, for a positive value...
+ */
+ __pformat_putc( '+', stream );
+
+ else if( stream->flags & PFORMAT_ADDSPACE )
+ /*
+ * with this optional alternative.
+ */
+ __pformat_putc( '\x20', stream );
+
+ /* Prefix a `0x' or `0X' radix indicator to the encoded value,
+ * with case appropriate to the format specification.
+ */
+ __pformat_putc( '0', stream );
+ __pformat_putc( 'X' | (stream->flags & PFORMAT_XCASE), stream );
+
+ /* If the `0' flag is in effect...
+ * Zero padding, to fill out the field, goes here...
+ */
+ if( (stream->width > 0) && (stream->flags & PFORMAT_ZEROFILL) )
+ while( stream->width-- > 0 )
+ __pformat_putc( '0', stream );
+
+ /* Next, we emit the encoded value, without its exponent...
+ */
+ while( p > buf )
+ __pformat_emit_numeric_value( *--p, stream );
+
+ /* followed by any additional zeros needed to satisfy the
+ * precision specification...
+ */
+ while( stream->precision-- > 0 )
+ __pformat_putc( '0', stream );
+
+ /* then the exponent prefix, (C99 and POSIX specify `p'),
+ * in the case appropriate to the format specification...
+ */
+ __pformat_putc( 'P' | (stream->flags & PFORMAT_XCASE), stream );
+
+ /* and finally, the decimal representation of the binary exponent,
+ * as a signed value with mandatory sign displayed, in a field width
+ * adjusted to accommodate it, LEFT justified, with any additional
+ * right side padding remaining from the original field width.
+ */
+ stream->width += exp_width;
+ stream->flags |= PFORMAT_SIGNED;
+ exponent.__pformat_llong_t = value.__pformat_fpreg_exponent;
+ __pformat_int( exponent, stream );
+}
+
+static
+void __pformat_xdouble( double x, __pformat_t *stream )
+{
+ /* Handler for `%a' and `%A' format specifiers, (with argument
+ * value specified as `double' type).
+ */
+ unsigned sign_bit = 0;
+ __pformat_fpreg_t z; z.__pformat_fpreg_double_t = x;
+
+ /* First check for NaN; it is emitted unsigned...
+ */
+ if( isnan( x ) )
+ __pformat_emit_inf_or_nan( sign_bit, "NaN", stream );
+
+ else
+ { /* Capture the sign bit up-front, so we can show it correctly
+ * even when the argument value is zero or infinite.
+ */
+ if( (sign_bit = (z.__pformat_fpreg_bitmap[3] & 0x8000)) != 0 )
+ stream->flags |= PFORMAT_NEGATIVE;
+
+ /* Check for infinity, (positive or negative)...
+ */
+ if( isinf( x ) )
+ /*
+ * displaying the appropriately signed indicator,
+ * when appropriate.
+ */
+ __pformat_emit_inf_or_nan( sign_bit, "Inf", stream );
+
+ else
+ { /* The argument value is a representable number...
+ * first move its exponent into the appropriate field...
+ */
+ z.__pformat_fpreg_bitmap[4] = (z.__pformat_fpreg_bitmap[3] >> 4) & 0x7FF;
+
+ /* Realign the mantissa, leaving space for a
+ * normalised most significant digit...
+ */
+ z.__pformat_fpreg_mantissa <<= 8;
+ z.__pformat_fpreg_bitmap[3] = (z.__pformat_fpreg_bitmap[3] & 0x0FFF);
+
+ /* Check for zero value...
+ */
+ if( z.__pformat_fpreg_exponent || z.__pformat_fpreg_mantissa )
+ {
+ /* and only when the value is non-zero,
+ * eliminate the bias from the exponent...
+ */
+ z.__pformat_fpreg_exponent -= 0x3FF;
+
+ /* Check for a possible denormalised value...
+ */
+ if( z.__pformat_fpreg_exponent > -126 )
+ /*
+ * and normalise when it isn't.
+ */
+ z.__pformat_fpreg_bitmap[3] += 0x1000;
+ }
+
+ /* Finally, hand the adjusted representation off to the generalised
+ * hexadecimal floating point format handler...
+ */
+ __pformat_emit_xfloat( z, stream );
+ }
+ }
+}
+
+static
+void __pformat_xldouble( long double x, __pformat_t *stream )
+{
+ /* Handler for `%La' and `%LA' format specifiers, (with argument
+ * value specified as `long double' type).
+ */
+ unsigned sign_bit = 0;
+ __pformat_fpreg_t z; z.__pformat_fpreg_ldouble_t = x;
+
+ /* First check for NaN; it is emitted unsigned...
+ */
+ if( isnan( x ) )
+ __pformat_emit_inf_or_nan( sign_bit, "NaN", stream );
+
+ else
+ { /* Capture the sign bit up-front, so we can show it correctly
+ * even when the argument value is zero or infinite.
+ */
+ if( (sign_bit = (z.__pformat_fpreg_exponent & 0x8000)) != 0 )
+ stream->flags |= PFORMAT_NEGATIVE;
+
+ /* Check for infinity, (positive or negative)...
+ */
+ if( isinf( x ) )
+ /*
+ * displaying the appropriately signed indicator,
+ * when appropriate.
+ */
+ __pformat_emit_inf_or_nan( sign_bit, "Inf", stream );
+
+ else
+ { /* The argument value is a representable number...
+ * extract the effective value of the biased exponent...
+ */
+ z.__pformat_fpreg_exponent &= 0x7FFF;
+ if( z.__pformat_fpreg_exponent || z.__pformat_fpreg_mantissa )
+ /*
+ * and if the argument value itself is non-zero,
+ * eliminate the bias from the exponent...
+ */
+ z.__pformat_fpreg_exponent -= 0x3FFF;
+
+ /* Finally, hand the adjusted representation off to the
+ * generalised hexadecimal floating point format handler...
+ */
+ __pformat_emit_xfloat( z, stream );
+ }
+ }
+}
+
+int __pformat( int flags, void *dest, int max, const char *fmt, va_list argv )
+{
+ int c;
+
+ __pformat_t stream =
+ {
+ /* Create and initialise a format control block
+ * for this output request.
+ */
+ dest, /* output goes to here */
+ flags &= PFORMAT_TO_FILE | PFORMAT_NOLIMIT, /* only these valid initially */
+ PFORMAT_IGNORE, /* no field width yet */
+ PFORMAT_IGNORE, /* nor any precision spec */
+ PFORMAT_RPINIT, /* radix point uninitialised */
+ (wchar_t)(0), /* leave it unspecified */
+ 0, /* zero output char count */
+ max, /* establish output limit */
+ PFORMAT_MINEXP /* exponent chars preferred */
+ };
+
+ format_scan: while( (c = *fmt++) != 0 )
+ {
+ /* Format string parsing loop...
+ * The entry point is labelled, so that we can return to the start state
+ * from within the inner `conversion specification' interpretation loop,
+ * as soon as a conversion specification has been resolved.
+ */
+ if( c == '%' )
+ {
+ /* Initiate parsing of a `conversion specification'...
+ */
+ __pformat_intarg_t argval;
+ __pformat_state_t state = PFORMAT_INIT;
+ __pformat_length_t length = PFORMAT_LENGTH_INT;
+
+ /* Save the current format scan position, so that we can backtrack
+ * in the event of encountering an invalid format specification...
+ */
+ const char *backtrack = fmt;
+
+ /* Restart capture for dynamic field width and precision specs...
+ */
+ int *width_spec = &stream.width;
+
+ /* Reset initial state for flags, width and precision specs...
+ */
+ stream.flags = flags;
+ stream.width = stream.precision = PFORMAT_IGNORE;
+
+ while( *fmt )
+ {
+ switch( c = *fmt++ )
+ {
+ /* Data type specifiers...
+ * All are terminal, so exit the conversion spec parsing loop
+ * with a `goto format_scan', thus resuming at the outer level
+ * in the regular format string parser.
+ */
+ case '%':
+ /*
+ * Not strictly a data type specifier...
+ * it simply converts as a literal `%' character.
+ *
+ * FIXME: should we require this to IMMEDIATELY follow the
+ * initial `%' of the "conversion spec"? (glibc `printf()'
+ * on GNU/Linux does NOT appear to require this, but POSIX
+ * and SUSv3 do seem to demand it).
+ */
+ __pformat_putc( c, &stream );
+ goto format_scan;
+
+ case 'C':
+ /*
+ * Equivalent to `%lc'; set `length' accordingly,
+ * and simply fall through.
+ */
+ length = PFORMAT_LENGTH_LONG;
+
+ case 'c':
+ /*
+ * Single, (or single multibyte), character output...
+ *
+ * We handle these by copying the argument into our local
+ * `argval' buffer, and then we pass the address of that to
+ * either `__pformat_putchars()' or `__pformat_wputchars()',
+ * as appropriate, effectively formatting it as a string of
+ * the appropriate type, with a length of one.
+ *
+ * A side effect of this method of handling character data
+ * is that, if the user sets a precision of zero, then no
+ * character is actually emitted; we don't want that, so we
+ * forcibly override any user specified precision.
+ */
+ stream.precision = PFORMAT_IGNORE;
+
+ /* Now we invoke the appropriate format handler...
+ */
+ if( (length == PFORMAT_LENGTH_LONG)
+ || (length == PFORMAT_LENGTH_LLONG) )
+ {
+ /* considering any `long' type modifier as a reference to
+ * `wchar_t' data, (which is promoted to an `int' argument)...
+ */
+ wchar_t argval = (wchar_t)(va_arg( argv, int ));
+ __pformat_wputchars( &argval, 1, &stream );
+ }
+
+ else
+ { /* while anything else is simply taken as `char', (which
+ * is also promoted to an `int' argument)...
+ */
+ argval.__pformat_uchar_t = (unsigned char)(va_arg( argv, int ));
+ __pformat_putchars( (char *)(&argval), 1, &stream );
+ }
+ goto format_scan;
+
+ case 'S':
+ /*
+ * Equivalent to `%ls'; set `length' accordingly,
+ * and simply fall through.
+ */
+ length = PFORMAT_LENGTH_LONG;
+
+ case 's':
+ if( (length == PFORMAT_LENGTH_LONG)
+ || (length == PFORMAT_LENGTH_LLONG) )
+ {
+ /* considering any `long' type modifier as a reference to
+ * a `wchar_t' string...
+ */
+ __pformat_wcputs( va_arg( argv, wchar_t * ), &stream );
+ }
+
+ else
+ /* This is normal string output;
+ * we simply invoke the appropriate handler...
+ */
+ __pformat_puts( va_arg( argv, char * ), &stream );
+
+ goto format_scan;
+
+ case 'o':
+ case 'u':
+ case 'x':
+ case 'X':
+ /*
+ * Unsigned integer values; octal, decimal or hexadecimal format...
+ */
+ if( length == PFORMAT_LENGTH_LLONG )
+ /*
+ * with an `unsigned long long' argument, which we
+ * process `as is'...
+ */
+ argval.__pformat_ullong_t = va_arg( argv, unsigned long long );
+
+ else if( length == PFORMAT_LENGTH_LONG )
+ /*
+ * or with an `unsigned long', which we promote to
+ * `unsigned long long'...
+ */
+ argval.__pformat_ullong_t = va_arg( argv, unsigned long );
+
+ else
+ { /* or for any other size, which will have been promoted
+ * to `unsigned int', we select only the appropriately sized
+ * least significant segment, and again promote to the same
+ * size as `unsigned long long'...
+ */
+ argval.__pformat_ullong_t = va_arg( argv, unsigned int );
+ if( length == PFORMAT_LENGTH_SHORT )
+ /*
+ * from `unsigned short'...
+ */
+ argval.__pformat_ullong_t = argval.__pformat_ushort_t;
+
+ else if( length == PFORMAT_LENGTH_CHAR )
+ /*
+ * or even from `unsigned char'...
+ */
+ argval.__pformat_ullong_t = argval.__pformat_uchar_t;
+ }
+
+ /* so we can pass any size of argument to either of two
+ * common format handlers...
+ */
+ if( c == 'u' )
+ /*
+ * depending on whether output is to be encoded in
+ * decimal format...
+ */
+ __pformat_int( argval, &stream );
+
+ else
+ /* or in octal or hexadecimal format...
+ */
+ __pformat_xint( c, argval, &stream );
+
+ goto format_scan;
+
+ case 'd':
+ case 'i':
+ /*
+ * Signed integer values; decimal format...
+ * This is similar to `u', but must process `argval' as signed,
+ * and be prepared to handle negative numbers.
+ */
+ stream.flags |= PFORMAT_NEGATIVE;
+
+ if( length == PFORMAT_LENGTH_LLONG )
+ /*
+ * The argument is a `long long' type...
+ */
+ argval.__pformat_llong_t = va_arg( argv, long long );
+
+ else if( length == PFORMAT_LENGTH_LONG )
+ /*
+ * or here, a `long' type...
+ */
+ argval.__pformat_llong_t = va_arg( argv, long );
+
+ else
+ { /* otherwise, it's an `int' type...
+ */
+ argval.__pformat_llong_t = va_arg( argv, int );
+ if( length == PFORMAT_LENGTH_SHORT )
+ /*
+ * but it was promoted from a `short' type...
+ */
+ argval.__pformat_llong_t = argval.__pformat_short_t;
+ else if( length == PFORMAT_LENGTH_CHAR )
+ /*
+ * or even from a `char' type...
+ */
+ argval.__pformat_llong_t = argval.__pformat_char_t;
+ }
+
+ /* In any case, all share a common handler...
+ */
+ __pformat_int( argval, &stream );
+ goto format_scan;
+
+ case 'p':
+ /*
+ * Pointer argument; format as hexadecimal, subject to...
+ */
+ if( (state == PFORMAT_INIT) && (stream.flags == flags) )
+ {
+ /* Here, the user didn't specify any particular
+ * formatting attributes. We must choose a default
+ * which will be compatible with Microsoft's (broken)
+ * scanf() implementation, (i.e. matching the default
+ * used by MSVCRT's printf(), which appears to resemble
+ * "%0.8X" for 32-bit pointers); in particular, we MUST
+ * NOT adopt a GNU-like format resembling "%#x", because
+ * Microsoft's scanf() will choke on the "0x" prefix.
+ */
+ stream.flags |= PFORMAT_ZEROFILL;
+ stream.precision = 2 * sizeof( uintptr_t );
+ }
+ argval.__pformat_ullong_t = va_arg( argv, uintptr_t );
+ __pformat_xint( 'x', argval, &stream );
+ goto format_scan;
+
+ case 'e':
+ /*
+ * Floating point format, with lower case exponent indicator
+ * and lower case `inf' or `nan' representation when required;
+ * select lower case mode, and simply fall through...
+ */
+ stream.flags |= PFORMAT_XCASE;
+
+ case 'E':
+ /*
+ * Floating point format, with upper case exponent indicator
+ * and upper case `INF' or `NAN' representation when required,
+ * (or lower case for all of these, on fall through from above);
+ * select lower case mode, and simply fall through...
+ */
+ if( stream.flags & PFORMAT_LDOUBLE )
+ /*
+ * for a `long double' argument...
+ */
+ __pformat_efloat( va_arg( argv, long double ), &stream );
+
+ else
+ /* or just a `double', which we promote to `long double',
+ * so the two may share a common format handler.
+ */
+ __pformat_efloat( (long double)(va_arg( argv, double )), &stream );
+
+ goto format_scan;
+
+ case 'f':
+ /*
+ * Fixed point format, using lower case for `inf' and
+ * `nan', when appropriate; select lower case mode, and
+ * simply fall through...
+ */
+ stream.flags |= PFORMAT_XCASE;
+
+ case 'F':
+ /*
+ * Fixed case format using upper case, or lower case on
+ * fall through from above, for `INF' and `NAN'...
+ */
+ if( stream.flags & PFORMAT_LDOUBLE )
+ /*
+ * for a `long double' argument...
+ */
+ __pformat_float( va_arg( argv, long double ), &stream );
+
+ else
+ /* or just a `double', which we promote to `long double',
+ * so the two may share a common format handler.
+ */
+ __pformat_float( (long double)(va_arg( argv, double )), &stream );
+
+ goto format_scan;
+
+ case 'g':
+ /*
+ * Generalised floating point format, with lower case
+ * exponent indicator when required; select lower case
+ * mode, and simply fall through...
+ */
+ stream.flags |= PFORMAT_XCASE;
+
+ case 'G':
+ /*
+ * Generalised floating point format, with upper case,
+ * or on fall through from above, with lower case exponent
+ * indicator when required...
+ */
+ if( stream.flags & PFORMAT_LDOUBLE )
+ /*
+ * for a `long double' argument...
+ */
+ __pformat_gfloat( va_arg( argv, long double ), &stream );
+
+ else
+ /* or just a `double', which we promote to `long double',
+ * so the two may share a common format handler.
+ */
+ __pformat_gfloat( (long double)(va_arg( argv, double )), &stream );
+
+ goto format_scan;
+
+ case 'a':
+ /*
+ * Hexadecimal floating point format, with lower case radix
+ * and exponent indicators; select the lower case mode, and
+ * fall through...
+ */
+ stream.flags |= PFORMAT_XCASE;
+
+ case 'A':
+ /*
+ * Hexadecimal floating point format; handles radix and
+ * exponent indicators in either upper or lower case...
+ */
+ if( stream.flags & PFORMAT_LDOUBLE )
+ /*
+ * with a `long double' argument...
+ */
+ __pformat_xldouble( va_arg( argv, long double ), &stream );
+
+ else
+ /* or just a `double'.
+ */
+ __pformat_xdouble( va_arg( argv, double ), &stream );
+
+ goto format_scan;
+
+ case 'n':
+ /*
+ * Save current output character count...
+ */
+ if( length == PFORMAT_LENGTH_CHAR )
+ /*
+ * to a signed `char' destination...
+ */
+ *va_arg( argv, char * ) = stream.count;
+
+ else if( length == PFORMAT_LENGTH_SHORT )
+ /*
+ * or to a signed `short'...
+ */
+ *va_arg( argv, short * ) = stream.count;
+
+ else if( length == PFORMAT_LENGTH_LONG )
+ /*
+ * or to a signed `long'...
+ */
+ *va_arg( argv, long * ) = stream.count;
+
+ else if( length == PFORMAT_LENGTH_LLONG )
+ /*
+ * or to a signed `long long'...
+ */
+ *va_arg( argv, long long * ) = stream.count;
+
+ else
+ /*
+ * or, by default, to a signed `int'.
+ */
+ *va_arg( argv, int * ) = stream.count;
+
+ goto format_scan;
+
+ /* Argument length modifiers...
+ * These are non-terminal; each sets the format parser
+ * into the PFORMAT_END state, and ends with a `break'.
+ */
+ case 'h':
+ /*
+ * Interpret the argument as explicitly of a `short'
+ * or `char' data type, truncated from the standard
+ * length defined for integer promotion.
+ */
+ if( *fmt == 'h' )
+ {
+ /* Modifier is `hh'; data type is `char' sized...
+ * Skip the second `h', and set length accordingly.
+ */
+ ++fmt;
+ length = PFORMAT_LENGTH_CHAR;
+ }
+
+ else
+ /* Modifier is `h'; data type is `short' sized...
+ */
+ length = PFORMAT_LENGTH_SHORT;
+
+ state = PFORMAT_END;
+ break;
+
+ case 'j':
+ /*
+ * Interpret the argument as being of the same size as
+ * a `intmax_t' entity...
+ */
+ length = __pformat_arg_length( intmax_t );
+ state = PFORMAT_END;
+ break;
+
+# ifdef _WIN32
+
+ case 'I':
+ /*
+ * The MSVCRT implementation of the printf() family of
+ * functions explicitly uses...
+ */
+ if( (fmt[0] == '6') && (fmt[1] == '4') )
+ {
+ /* I64' instead of `ll',
+ * when referring to `long long' integer types...
+ */
+ length = PFORMAT_LENGTH_LLONG;
+ fmt += 2;
+ }
+
+ else if( (fmt[0] == '3') && (fmt[1] == '2') )
+ {
+ /* and `I32' instead of `l',
+ * when referring to `long' integer types...
+ */
+ length = PFORMAT_LENGTH_LONG;
+ fmt += 2;
+ }
+
+ else
+ /* or unqualified `I' instead of `t' or `z',
+ * when referring to `ptrdiff_t' or `size_t' entities;
+ * (we will choose to map it to `ptrdiff_t').
+ */
+ length = __pformat_arg_length( ptrdiff_t );
+
+ state = PFORMAT_END;
+ break;
+
+# endif
+
+ case 'l':
+ /*
+ * Interpret the argument as explicitly of a
+ * `long' or `long long' data type.
+ */
+ if( *fmt == 'l' )
+ {
+ /* Modifier is `ll'; data type is `long long' sized...
+ * Skip the second `l', and set length accordingly.
+ */
+ ++fmt;
+ length = PFORMAT_LENGTH_LLONG;
+ }
+
+ else
+ /* Modifier is `l'; data type is `long' sized...
+ */
+ length = PFORMAT_LENGTH_LONG;
+
+# ifndef _WIN32
+ /*
+ * Microsoft's MSVCRT implementation also uses `l'
+ * as a modifier for `long double'; if we don't want
+ * to support that, we end this case here...
+ */
+ state = PFORMAT_END;
+ break;
+
+ /* otherwise, we simply fall through...
+ */
+# endif
+
+ case 'L':
+ /*
+ * Identify the appropriate argument as a `long double',
+ * when associated with `%a', `%A', `%e', `%E', `%f', `%F',
+ * `%g' or `%G' format specifications.
+ */
+ stream.flags |= PFORMAT_LDOUBLE;
+ state = PFORMAT_END;
+ break;
+
+ case 't':
+ /*
+ * Interpret the argument as being of the same size as
+ * a `ptrdiff_t' entity...
+ */
+ length = __pformat_arg_length( ptrdiff_t );
+ state = PFORMAT_END;
+ break;
+
+ case 'z':
+ /*
+ * Interpret the argument as being of the same size as
+ * a `size_t' entity...
+ */
+ length = __pformat_arg_length( size_t );
+ state = PFORMAT_END;
+ break;
+
+ /* Precision indicator...
+ * May appear once only; it must precede any modifier
+ * for argument length, or any data type specifier.
+ */
+ case '.':
+ if( state < PFORMAT_GET_PRECISION )
+ {
+ /* We haven't seen a precision specification yet,
+ * so initialise it to zero, (in case no digits follow),
+ * and accept any following digits as the precision.
+ */
+ stream.precision = 0;
+ width_spec = &stream.precision;
+ state = PFORMAT_GET_PRECISION;
+ }
+
+ else
+ /* We've already seen a precision specification,
+ * so this is just junk; proceed to end game.
+ */
+ state = PFORMAT_END;
+
+ /* Either way, we must not fall through here.
+ */
+ break;
+
+ /* Variable field width, or precision specification,
+ * derived from the argument list...
+ */
+ case '*':
+ /*
+ * When this appears...
+ */
+ if( width_spec
+ && ((state == PFORMAT_INIT) || (state == PFORMAT_GET_PRECISION)) )
+ {
+ /* in proper context; assign to field width
+ * or precision, as appropriate.
+ */
+ if( (*width_spec = va_arg( argv, int )) < 0 )
+ {
+ /* Assigned value was negative...
+ */
+ if( state == PFORMAT_INIT )
+ {
+ /* For field width, this is equivalent to
+ * a positive value with the `-' flag...
+ */
+ stream.flags |= PFORMAT_LJUSTIFY;
+ stream.width = -stream.width;
+ }
+
+ else
+ /* while as a precision specification,
+ * it should simply be ignored.
+ */
+ stream.precision = PFORMAT_IGNORE;
+ }
+ }
+
+ else
+ /* out of context; give up on width and precision
+ * specifications for this conversion.
+ */
+ state = PFORMAT_END;
+
+ /* Mark as processed...
+ * we must not see `*' again, in this context.
+ */
+ width_spec = NULL;
+ break;
+
+ /* Formatting flags...
+ * Must appear while in the PFORMAT_INIT state,
+ * and are non-terminal, so again, end with `break'.
+ */
+ case '#':
+ /*
+ * Select alternate PFORMAT_HASHED output style.
+ */
+ if( state == PFORMAT_INIT )
+ stream.flags |= PFORMAT_HASHED;
+ break;
+
+ case '+':
+ /*
+ * Print a leading sign with numeric output,
+ * for both positive and negative values.
+ */
+ if( state == PFORMAT_INIT )
+ stream.flags |= PFORMAT_POSITIVE;
+ break;
+
+ case '-':
+ /*
+ * Select left justification of displayed output
+ * data, within the output field width, instead of
+ * the default flush right justification.
+ */
+ if( state == PFORMAT_INIT )
+ stream.flags |= PFORMAT_LJUSTIFY;
+ break;
+
+# ifdef WITH_XSI_FEATURES
+
+ case '\'':
+ /*
+ * This is an XSI extension to the POSIX standard,
+ * which we do not support, at present.
+ */
+ if( state == PFORMAT_INIT )
+ stream.flags |= PFORMAT_GROUPED;
+ break;
+
+# endif
+
+ case '\x20':
+ /*
+ * Reserve a single space, within the output field,
+ * for display of the sign of signed data; this will
+ * be occupied by the minus sign, if the data value
+ * is negative, or by a plus sign if the data value
+ * is positive AND the `+' flag is also present, or
+ * by a space otherwise. (Technically, this flag
+ * is redundant, if the `+' flag is present).
+ */
+ if( state == PFORMAT_INIT )
+ stream.flags |= PFORMAT_ADDSPACE;
+ break;
+
+ case '0':
+ /*
+ * May represent a flag, to activate the `pad with zeros'
+ * option, or it may simply be a digit in a width or in a
+ * precision specification...
+ */
+ if( state == PFORMAT_INIT )
+ {
+ /* This is the flag usage...
+ */
+ stream.flags |= PFORMAT_ZEROFILL;
+ break;
+ }
+
+ default:
+ /*
+ * If we didn't match anything above, then we will check
+ * for digits, which we may accumulate to generate field
+ * width or precision specifications...
+ */
+ if( (state < PFORMAT_END) && ('9' >= c) && (c >= '0') )
+ {
+ if( state == PFORMAT_INIT )
+ /*
+ * Initial digits explicitly relate to field width...
+ */
+ state = PFORMAT_SET_WIDTH;
+
+ else if( state == PFORMAT_GET_PRECISION )
+ /*
+ * while those following a precision indicator
+ * explicitly relate to precision.
+ */
+ state = PFORMAT_SET_PRECISION;
+
+ if( width_spec )
+ {
+ /* We are accepting a width or precision specification...
+ */
+ if( *width_spec < 0 )
+ /*
+ * and accumulation hasn't started yet; we simply
+ * initialise the accumulator with the current digit
+ * value, converting from ASCII to decimal.
+ */
+ *width_spec = c - '0';
+
+ else
+ /* Accumulation has already started; we perform a
+ * `leftwise decimal digit shift' on the accumulator,
+ * (i.e. multiply it by ten), then add the decimal
+ * equivalent value of the current digit.
+ */
+ *width_spec = *width_spec * 10 + c - '0';
+ }
+ }
+
+ else
+ {
+ /* We found a digit out of context, or some other character
+ * with no designated meaning; reject this format specification,
+ * backtrack, and emit it as literal text...
+ */
+ fmt = backtrack;
+ __pformat_putc( '%', &stream );
+ goto format_scan;
+ }
+ }
+ }
+ }
+
+ else
+ /* We just parsed a character which is not included within any format
+ * specification; we simply emit it as a literal.
+ */
+ __pformat_putc( c, &stream );
+ }
+
+ /* When we have fully dispatched the format string, the return value is the
+ * total number of bytes we transferred to the output destination.
+ */
+ return stream.count;
+}
+
+/* $RCSfile$Revision$: end of file */
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