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[psaux] Improve parsing of invalid numbers.

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* src/psaux/psconv.c (PS_Conv_Strtol): Always parse complete number,
even in case of overflow.
(PS_Conv_ToInt): Only increase cursor if parsing was successful.
(PS_Conv_ToFixed): Ditto.
Trace underflow and data error.
This commit is contained in:
Werner Lemberg 2012-10-21 11:02:50 +02:00
parent fdcbaf19fe
commit 8e82a961e7
2 changed files with 128 additions and 46 deletions
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10
ChangeLog
View File

@ -1,3 +1,13 @@
2012-10-21 Werner Lemberg <wl@gnu.org>
[psaux] Improve parsing of invalid numbers.
* src/psaux/psconv.c (PS_Conv_Strtol): Always parse complete number,
even in case of overflow.
(PS_Conv_ToInt): Only increase cursor if parsing was successful.
(PS_Conv_ToFixed): Ditto.
Trace underflow and data error.
2012-10-21 Werner Lemberg <wl@gnu.org>
[smooth] Improve tracing.

164
src/psaux/psconv.c
View File

@ -86,8 +86,10 @@
FT_Long base )
{
FT_Byte* p = *cursor;
FT_Long num = 0;
FT_Bool sign = 0;
FT_Long num = 0;
FT_Bool sign = 0;
FT_Bool have_overflow = 0;
FT_Long num_limit;
FT_Char c_limit;
@ -128,27 +130,27 @@
break;
if ( num > num_limit || ( num == num_limit && c > c_limit ) )
goto Overflow;
num = num * base + c;
have_overflow = 1;
else
num = num * base + c;
}
*cursor = p;
Exit:
if ( have_overflow )
{
num = 0x7FFFFFFFL;
FT_TRACE4(( "!!!OVERFLOW:!!!" ));
}
if ( sign )
num = -num;
return num;
Overflow:
num = 0x7FFFFFFFL;
FT_TRACE4(( "!!!OVERFLOW:!!!" ));
goto Exit;
Bad:
num = 0;
FT_TRACE4(( "!!!END OF DATA:!!!" ));
goto Exit;
return 0;
}
@ -157,21 +159,32 @@
FT_Byte* limit )
{
FT_Byte* p;
FT_Byte* p = *cursor;
FT_Byte* curp;
FT_Long num;
num = PS_Conv_Strtol( cursor, limit, 10 );
p = *cursor;
curp = p;
num = PS_Conv_Strtol( &p, limit, 10 );
if ( p == curp )
return 0;
if ( p < limit && *p == '#' )
{
*cursor = p + 1;
p++;
return PS_Conv_Strtol( cursor, limit, num );
curp = p;
num = PS_Conv_Strtol( &p, limit, num );
if ( p == curp )
return 0;
}
else
return num;
*cursor = p;
return num;
}
@ -181,13 +194,19 @@
FT_Long power_ten )
{
FT_Byte* p = *cursor;
FT_Fixed integral;
FT_Long decimal = 0, divider = 1;
FT_Bool sign = 0;
FT_Byte* curp;
FT_Fixed integral = 0;
FT_Long decimal = 0;
FT_Long divider = 1;
FT_Bool sign = 0;
FT_Bool have_overflow = 0;
FT_Bool have_underflow = 0;
if ( p >= limit )
return 0;
goto Bad;
if ( *p == '-' || *p == '+' )
{
@ -195,20 +214,23 @@
p++;
if ( p == limit )
return 0;
goto Bad;
}
/* read the integer part */
if ( *p != '.' )
{
curp = p;
integral = PS_Conv_ToInt( &p, limit );
if ( integral > 0x7FFF )
return sign ? -0x7FFFFFFFL : 0x7FFFFFFFL;
if ( p == curp )
return 0;
integral <<= 16;
if ( integral > 0x7FFF )
have_overflow = 1;
else
integral <<= 16;
}
else
integral = 0;
/* read the decimal part */
if ( p < limit && *p == '.' )
@ -228,18 +250,14 @@
if ( c < 0 || c >= 10 )
break;
if ( !integral && power_ten > 0 )
if ( decimal < 0xCCCCCCCL )
{
power_ten--;
decimal = decimal * 10 + c;
}
else
{
if ( divider < 10000000L )
{
decimal = decimal * 10 + c;
if ( !integral && power_ten > 0 )
power_ten--;
else
divider *= 10;
}
}
}
}
@ -247,40 +265,94 @@
/* read exponent, if any */
if ( p + 1 < limit && ( *p == 'e' || *p == 'E' ) )
{
FT_Long exponent;
p++;
power_ten += PS_Conv_ToInt( &p, limit );
curp = p;
exponent = PS_Conv_ToInt( &p, limit );
if ( curp == p )
return 0;
/* arbitrarily limit exponent */
if ( exponent > 1000 )
have_overflow = 1;
else if ( exponent < -1000 )
have_underflow = 1;
else
power_ten += exponent;
}
*cursor = p;
if ( !integral && !decimal )
return 0;
if ( have_overflow )
goto Overflow;
if ( have_underflow )
goto Underflow;
while ( power_ten > 0 )
{
if ( integral >= 0xCCCCCCCL )
return sign ? -0x7FFFFFFFL : 0x7FFFFFFFL;
goto Overflow;
integral *= 10;
decimal *= 10;
if ( decimal >= 0xCCCCCCCL )
{
if ( divider == 1 )
goto Overflow;
divider /= 10;
}
else
decimal *= 10;
power_ten--;
}
while ( power_ten < 0 )
{
integral /= 10;
divider *= 10;
if ( divider < 0xCCCCCCCL )
divider *= 10;
else
decimal /= 10;
if ( !integral && !decimal )
goto Underflow;
power_ten++;
}
if ( decimal )
{
decimal = FT_DivFix( decimal, divider );
if ( 0x7FFFFFFFL - decimal < integral )
return sign ? -0x7FFFFFFFL : 0x7FFFFFFFL;
/* it's not necessary to check this addition for overflow */
/* due to the structure of the real number representation */
integral += decimal;
}
Exit:
if ( sign )
integral = -integral;
*cursor = p;
return integral;
Bad:
FT_TRACE4(( "!!!END OF DATA:!!!" ));
return 0;
Overflow:
integral = 0x7FFFFFFFL;
FT_TRACE4(( "!!!OVERFLOW:!!!" ));
goto Exit;
Underflow:
FT_TRACE4(( "!!!UNDERFLOW:!!!" ));
return 0;
}