Bug#158704: gcc: gcc compiles incorrect loop

[Bart Samwel <bsamwel@liacs.nl>]

Eugene,

This code is completely correct as far as I can see. The second while is 
interpreted as a new while loop, and the closing; is short for {} in 
this case. I've expanded the code into a more intuitive form here:

int main()
{
  int a = 0;

  while (a == 0) {
    a = 1;
  }

  while (1)
    /* Do nothing */ ;

  return 0;
}

Regards,
Bart Samwel

Eugene Morozov wrote:
> Package: gcc
> Version: 2:2.95.4-16
> Severity: normal
>
> gcc compiles following program without emitting warning even with
> -Wall -ansi -pedantic. gcc-3.2 also compiles this program.
>
> int main() 
> {
>   int a = 0;
>   
>   while (a == 0) {
>     a = 1;
>   } while (1);
>   
>   return 0;
> }
>
> -- System Information
> Debian Release: 3.0
> Kernel Version: Linux tanya 2.4.18 #1 Fri Apr 19 18:18:18 MSD 2002 i686 unknown unknown GNU/Linux
>
> Versions of the packages gcc depends on:
> ii  cpp-2.95       2.95.4-2       The GNU C preprocessor.
> ii  cpp            2.95.4-16      The GNU C preprocessor.
> ii  gcc-2.95       2.95.4-2       The GNU C compiler.



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Leiden Institute of Advanced Computer Science (LIACS)
E-mail: bsamwel@liacs.nl    Telephone: +31-71-5277037
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