Re: PATCH: Correct alloca length in dump_gimple_bb_header

["H.J. Lu" <hjl dot tools at gmail dot com>]

On Mon, Oct 29, 2012 at 5:18 AM, Jakub Jelinek <jakub@redhat.com> wrote:
> On Mon, Oct 29, 2012 at 05:06:01AM -0700, H.J. Lu wrote:
>> When indent == 0, we call alloca with -1 bytes.  This patch changes
>> it to indent + 1.  This is a trunk only regression.  OK to install?
>
>> 2012-10-29  H.J. Lu  <hongjiu.lu@intel.com>
>>
>>       * gimple-pretty-print.c (dump_gimple_bb_header): Correct alloca
>>       length.
>>
>> diff --git a/gcc/gimple-pretty-print.c b/gcc/gimple-pretty-print.c
>> index 4b3235e..62c315e 100644
>> --- a/gcc/gimple-pretty-print.c
>> +++ b/gcc/gimple-pretty-print.c
>> @@ -2093,7 +2093,7 @@ dump_gimple_bb_header (FILE *outf, basic_block bb, int indent, int flags)
>>        gimple stmt = first_stmt (bb);
>>        if (!stmt || gimple_code (stmt) != GIMPLE_LABEL)
>>       {
>> -       char *s_indent = (char *) alloca ((size_t) indent - 2 + 1);
>> +       char *s_indent = (char *) alloca ((size_t) indent + 1);
>>         memset (s_indent, ' ', (size_t) indent);
>>         s_indent[indent] = '\0';
>>         fprintf (outf, "%s<bb %d>:\n", s_indent, bb->index);
>
> Can't you instead of all this just do
>   fprintf (outf, "%*s<bb %d>:\n", indent, "", bb->index);
> ?
>

The whole function has another:

         char *s_indent = (char *) alloca ((size_t) indent + 1);
          memset (s_indent, ' ', (size_t) indent);
          s_indent[indent] = '\0';

We should make the same switch for both.

-- 
H.J.