[Tinycc-devel] RE :Re: add warning for signed unsigned comparisions

[Christian JULLIEN]

Remember that the signess of char is implementation, more especially machine, dependant.

The correct way to insure num_signed is signed is to declare

  signed char num_signed = 128;
  unsigned char num_unsigned = 128;

On a machine where a char is unsigned, the compiler has no reasons to protest unless it use something like warn-portability. Generally, most compilers have a flag like char=signed for force signess

Christian

----- Message d'origine -----
De : "Romain ..." <address@hidden>
Date ven. 10/01/2014 10:48 (GMT +01:00)
À : "address@hidden" <address@hidden>
Objet : Re: [Tinycc-devel] add warning for signed unsigned comparisions

Hi Carlos

It would be interresting to test wether the same bug happens with lower numbers. Because I found two different reasons for this behaviours : either there's a problem with assigning 128 to a signed char (which is supposed to be bound to -128 +127) or it is caussed by an implicit cast during the comparison.

It's strange because gcc haven't this behaviour.

regards,
Romain

On Jan 6, 2014 4:58 PM, "Carlos Montiers" <address@hidden> wrote:

Hello. Please can add support for tiny c warning signed comparisions with unsigned comparisions.

 

For warning code like this:

 

#include <stdio.h>

int main()
{
  char num_signed = 128;
  unsigned char num_unsigned = 128;

  if (num_signed == num_unsigned) {
    printf("Equals\n");
  } else {
    printf("Not Equals\n");
  }

  return 0;
}

 

 

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