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Include <float.h> if STDC_HEADERS.

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(DBL_MAX_10_EXP): Define if not defined; default is IEEE double.
(doprnt1): Allocate enough buffer space to handle very large floating
point numbers, or very large field widths or precisions.
Detect overflow in field widths or precisions.
This commit is contained in:
Paul Eggert 1997-01-27 20:12:52 +00:00
parent dd713b759c
commit be65c2f46a
1 changed files with 37 additions and 13 deletions
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50
src/doprnt.c
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@ -26,6 +26,14 @@ Boston, MA 02111-1307, USA. */
#include <ctype.h>
#include "lisp.h"
#if STDC_HEADERS
#include <float.h>
#endif
#ifndef DBL_MAX_10_EXP
#define DBL_MAX_10_EXP 308 /* IEEE double */
#endif
extern long *xmalloc (), *xrealloc ();
static int doprnt1 ();
@ -80,10 +88,10 @@ doprnt1 (lispstrings, buffer, bufsize, format, format_end, nargs, args)
register char *bufptr = buffer; /* Pointer into output buffer.. */
/* Use this for sprintf unless we need something really big. */
char tembuf[100];
char tembuf[DBL_MAX_10_EXP + 100];
/* Size of sprintf_buffer. */
int size_allocated = 100;
int size_allocated = sizeof (tembuf);
/* Buffer to use for sprintf. Either tembuf or same as BIG_BUFFER. */
char *sprintf_buffer = tembuf;
@ -114,7 +122,7 @@ doprnt1 (lispstrings, buffer, bufsize, format, format_end, nargs, args)
{
if (*fmt == '%') /* Check for a '%' character */
{
int size_bound;
int size_bound = 0;
fmt++;
/* Copy this one %-spec into fmtcpy. */
@ -123,22 +131,38 @@ doprnt1 (lispstrings, buffer, bufsize, format, format_end, nargs, args)
while (1)
{
*string++ = *fmt;
if (! (*fmt >= '0' && *fmt <= '9')
&& *fmt != '-' && *fmt != ' '&& *fmt != '.')
if ('0' <= *fmt && *fmt <= '9')
{
/* Get an idea of how much space we might need.
This might be a field width or a precision; e.g.
%1.1000f and %1000.1f both might need 1000+ bytes.
Parse the width or precision, checking for overflow. */
int n = *fmt - '0';
while ('0' <= fmt[1] && fmt[1] <= '9')
{
if (n * 10 / 10 != n
|| (n = n * 10 + (fmt[1] - '0')) < 0)
error ("Format width or precision too large");
*string++ = *++fmt;
}
if (size_bound < n)
size_bound = n;
}
else if (*fmt == '-' || *fmt == ' ' || *fmt == '.')
;
else
break;
fmt++;
}
*string = 0;
/* Get an idea of how much space we might need. */
size_bound = atoi (&fmtcpy[1]);
/* Avoid pitfall of negative "size" parameter ("%-200d"). */
/* Make the size bound large enough to handle floating point formats
with large numbers. */
size_bound += DBL_MAX_10_EXP + 50;
if (size_bound < 0)
size_bound = -size_bound;
size_bound += 50;
if (size_bound > (((unsigned) 1) << (BITS_PER_INT - 1)))
error ("Format padding too large");
error ("Format width or precision too large");
/* Make sure we have that much. */
if (size_bound > size_allocated)