number of semicolons

[Pietro Cerutti]

Hi group,

is the below valid?

int main(void)
{
int i = 4;;;;;;;;
}

It compiles cleanly with GCC -Wall.

I don't see any reason for that, any clarification is welcome!

Thanks,

 

[Malcolm McLean]

Hi group,

is the below valid?

int main(void)
{
int i = 4;;;;;;;;
}

It compiles cleanly with GCC -Wall.

I don't see any reason for that, any clarification is welcome!

The null statement is allowed.

It means you can do things like

/* execute foo() until it return a zero */
while( foo() );

instead of having to write

while( foo() )
continue;

Obviously your example was pointless, but it would be harder to forbid it
than to allow it.

 

[Pietro Cerutti]

The null statement is allowed.

It means you can do things like

/* execute foo() until it return a zero */
while( foo() );

instead of having to write

while( foo() )
continue;

Obviously your example was pointless, but it would be harder to forbid
it than to allow it.

Obvious... my example (which comes from a typo I did) was so pointless
that I didn't see it as a sequence of null operations...

Thanks and sorry for the noise...

 

[fred.l.kleinschmidt]

Obvious... my example (which comes from a typo I did) was so pointless
that I didn't see it as a sequence of null operations...

Thanks and sorry for the noise...

--
Pietro Cerutti

PGP Public Key:http://gahr.ch/pgp- Hide quoted text -

- Show quoted text -

But be careful under C89:
This compiles fine with no complaints:

void foo() {
int i;
int j;;

i = 2;
/* more code here */
}

But then you decide to add another variable:

void foo() {
int i;
int j;;
int k;

i = 2;
/* more code here */
}

Now the compiler complains, and you have a hard time trying to
figure out why adding "int k;" could cause a problem.

 

[Pietro Cerutti]

But be careful under C89:
This compiles fine with no complaints:

void foo() {
int i;
int j;;

i = 2;
/* more code here */
}

But then you decide to add another variable:

void foo() {
int i;
int j;;
int k;

i = 2;
/* more code here */
}

Now the compiler complains, and you have a hard time trying to
figure out why adding "int k;" could cause a problem.

Very sharp point. Thanks!