Re: [Tinycc-devel] bug

[Brian Callahan]

On 6/8/2022 10:51 AM, Brian Callahan wrote:
> On 6/8/2022 10:03 AM, lrt via Tinycc-devel wrote:
>> Find a bug!
>>
>> #include <stdio.h>
>> #include <math.h>
>> #include <time.h>
>>
>> int main(int argc, char **argv)
>> {
>> printf("Hello!\n");
>> printf("%lld\n", 641*6700417);
>> return 0;
>> }
>> output:
>> Hello!
>> 7035757726269441
>>
>> Right is :
>> Hello!
>> 4294967297
>>
> 
> No, 4294967297 is not the correct output for this program. Check it
> yourself. You'll get this warning with both GCC and Clang:
> 
> /home/brian/c $ gcc --version
> gcc (GCC) 13.0.0 20220508 (experimental)
> Copyright (C) 2022 Free Software Foundation, Inc.
> This is free software; see the source for copying conditions.  There is NO
> warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
> 
> /home/brian/c $ gcc -O2 -o bug bug.c
> bug.c: In function 'main':
> bug.c:8:29: warning: integer overflow in expression of type 'int'
> results in '1' [-Woverflow]
>     8 |         printf("%lld\n", 641*6700417);
>       |                             ^
> /home/brian/c $ ./bug
> Hello!
> 1
> /home/brian/c $ tcc --version
> tcc version 0.9.27 mob:afc1362 (x86_64 OpenBSD)
> /home/brian/c $ tcc -o bug bug.c
> /home/brian/c $ ./bug
> Hello!
> 1
> 
> If you really want 4294967297 to be output, change 6700417 to 6700417L

Typed too fast, should be LL here.

.
> Works with both GCC and TCC.
> 
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