pike.git/ src/ operators.c

2009-07-12

2009-07-12 19:43:05 by Henrik Grubbström (Grubba) <grubba@grubba.org>

• d6b23851a33df041424a568ec2d2cdbf2f513179 (23 lines) (+11/-12) ^{[ Show | Annotate ]}
  Branch: 7.9

Improved calculation of MAX_FLOAT_SPRINTF_LEN
Added MAX_FLOAT_EXP_LEN.
MAX_FLOAT_PREC_LEN now only contains space for the mantissa.
Reverted previous commit.
Fixes single byte overflow for cast_to_string() when SIZEOF_FLOAT_TYPE = 8.

Rev: src/operators.c:1.250

2:   || This file is part of Pike. For copyright information see COPYRIGHT.   || Pike is distributed under GPL, LGPL and MPL. See the file COPYING   || for more information. - || $Id: operators.c,v 1.249 2009/07/12 11:48:23 grubba Exp $ + || $Id: operators.c,v 1.250 2009/07/12 19:43:05 grubba Exp $   */      #include "global.h"
49:   #define PIKE_MERGE_DESTR_A 0       /* These calculations should always give some margin based on the size. */ +  /* The calculations utilize that log10(256) ~= 2.4 < 5/2. */ +     /* One extra char for the sign. */   #define MAX_INT_SPRINTF_LEN (1 + (SIZEOF_INT_TYPE * 5 + 1) / 2) -  - #define MAX_FLOAT_PREC_LEN ((SIZEOF_FLOAT_TYPE * 5 + 1) / 2) +  /* Three quarters of the float is the mantissa. */ + #define MAX_FLOAT_PREC_LEN ((SIZEOF_FLOAT_TYPE * 15 + 4) / 8) +  /* One quarter of the float is the exponent. */ + #define MAX_FLOAT_EXP_LEN ((SIZEOF_FLOAT_TYPE * 5 + 4) / 8)    /* Six extra chars: Mantissa sign, decimal point, zero before the    * decimal point, the 'e', exponent sign, and an extra digit due    * to the mantissa/exponent split. */ - #define MAX_FLOAT_SPRINTF_LEN (6 + MAX_FLOAT_PREC_LEN) + #define MAX_FLOAT_SPRINTF_LEN (6 + MAX_FLOAT_PREC_LEN + MAX_FLOAT_EXP_LEN)       /* Enough to hold a Pike float or int in textform including a trailing \0    */
481:    return;       case T_FLOAT: -  if (sp[-1].u.float_number < 0) { -  /* Some libc's have bugs in the handling of large negative floats... */ -  sprintf(buf,"-%.*"PRINTPIKEFLOAT"g", -  MAX_FLOAT_PREC_LEN, -sp[-1].u.float_number); -  } else { +     sprintf(buf,"%.*"PRINTPIKEFLOAT"g",    MAX_FLOAT_PREC_LEN, sp[-1].u.float_number); -  } +     /* Ensure that either an exponent or a decimal point gets printed,    * since %g can remove both which would make it look like an integer. */    if (!strchr (buf, '.') && !strchr (buf, 'e'))