[PATCH] Handle '\0' in strcmp in RTL expansion (PR tree-optimization/90892).

[Martin Liška]

On 6/18/19 10:23 AM, Martin Liška wrote:
> On 6/18/19 10:11 AM, Jakub Jelinek wrote:
>> On Tue, Jun 18, 2019 at 10:07:50AM +0200, Martin Liška wrote:
>>> diff --git a/gcc/builtins.c b/gcc/builtins.c
>>> index 3463ffb1539..b58e1e58d4d 100644
>>> --- a/gcc/builtins.c
>>> +++ b/gcc/builtins.c
>>> @@ -7142,6 +7142,20 @@ inline_expand_builtin_string_cmp (tree exp, rtx target)
>>>    const char *src_str1 = c_getstr (arg1, &len1);
>>>    const char *src_str2 = c_getstr (arg2, &len2);
>>>  
>>> +  if (src_str1 != NULL)
>>> +    {
>>> +      unsigned HOST_WIDE_INT str_str1_strlen = strnlen (src_str1, len1);
>>> +      if (str_str1_strlen + 1 < len1)
>>> +	len1 = str_str1_strlen + 1;
>>
>> You really don't need any of this after strnlen.  strnlen is already
>> guaranteed to return a number from 0 to len1 inclusive, so you can really
>> just do:
>>   if (src_str1 != NULL)
>>     len1 = strnlen (src_str1, len1);
>>
>> 	Jakub
>>
> 
> Got it, I'm testing that.
> 
> Martin
> 

Ok, there's an off-by-one error in the previous patch candidate.
Patch can bootstrap on x86_64-linux-gnu and survives regression tests.

Ready to be installed?
Thanks,
Martin
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