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(parse_escape): Diagnose '\x' with no digits. 

Diagnose integer overflow when parsing \x escapes.

From-SVN: r2147
This commit is contained in:
Richard Stallman 1992-09-17 21:11:17 +00:00
parent 0e14ddbcfc
commit f46ffce4f8
1 changed files with 10 additions and 5 deletions
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15
gcc/cexp.y
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@ -803,23 +803,28 @@ parse_escape (string_ptr)
}
case 'x':
{
register int i = 0;
register unsigned i = 0, overflow = 0, digits_found = 0, digit;
for (;;)
{
c = *(*string_ptr)++;
if (c >= '0' && c <= '9')
i = (i << 4) + c - '0';
digit = c - '0';
else if (c >= 'a' && c <= 'f')
i = (i << 4) + c - 'a' + 10;
digit = c - 'a' + 10;
else if (c >= 'A' && c <= 'F')
i = (i << 4) + c - 'A' + 10;
digit = c - 'A' + 10;
else
{
(*string_ptr)--;
break;
}
overflow |= i ^ (i << 4 >> 4);
i = (i << 4) + digit;
digits_found = 1;
}
if ((i & ~((1 << BITS_PER_UNIT) - 1)) != 0)
if (!digits_found)
yyerror ("\\x used with no following hex digits");
if (overflow | (i & ~((1 << BITS_PER_UNIT) - 1)))
{
i &= (1 << BITS_PER_UNIT) - 1;
warning ("hex character constant does not fit in a byte");