MISRA-C

(for example the "Goto must not be used." rule).

that rule is broken "every day by everybody"

What is a switch statement but a bunch of "if - goto" statements?

HOWEVER, the C 'structure' does not lend itself very well to the implemetation of GOTO, so, thinking of it I have no assembler that is not full of GOTO and no C that has any.

Erik

(for example the "Goto must not be used." rule).

that rule is broken "every day by everybody"

What is a switch statement but a bunch of "if - goto" statements?

HOWEVER, the C 'structure' does not lend itself very well to the implemetation of GOTO, so, thinking of it I have no assembler that is not full of GOTO and no C that has any.

Erik

that rule is broken "every day by everybody"<p>

If you want to write code in compliance with MISRA-C rules, you better not break that rule, or your code will not comply with the standard anymore.

Same thing goes for using a break; statement outside a switch/case structure, using a continue; statement, or using more than one return statement in a function.

"Same thing goes for using a break; statement outside a switch/case structure, using a continue; statement, or using more than one return statement in a function."

Oops! Bad Dan. Bad, bad Dan!

that rule is broken that rule is broken "every day by everybody"<p>

If you want to write code in compliance with MISRA-C rules, you better not break that rule, or your code will not comply with the standard anymore.

I did not say anything about that an actual GOTO statement was used "every day by everybody", what I said is that a switch statement is the equivalent of (if - goto) and thus if you use a switch statement (which MISRA allows) you are in fact using GOTOs.

Erik

"a switch statement is the equivalent of (if - goto)"

equiverlent of goto in 8051 is jmp yes

you be try writing assemblery with no jmp and yeou have only v little code you know

but docomenent is MISRA-C not MISRA-8051 so not good to say equiverelent switch if-goto

whot profffesional C coder do use goto????? i not know you know

i do not you thinking yes

goto really is useful in some situations.

However, all usage should be very similar to the usage of break and continue, but with the ability to make it multi-level, i.e. to break out of (or restart) more than one encapsulation.

You might have a function:

void fnk(void) {

restart:
    do_something();
    for (;;) {
        do_more();
        switch (x) {
            case 1:
                if (error) goto fail;
                do_work();
                break;
            case 10:
                do_even_more();
                break;
            default:
                goto restart;
        }
    }

fail:
    do_cleanup();
}

Yes, it is possible to solve all flow problems with flags, a large set of conditionals, and optional extra loops, but there comes a point where these flags gets very hard to read. The code must check if it should leave (or restart) first level, then second level, ...

"... but there comes a point where these flags gets very hard to read."

And thus become a potential source of errors themselves when the logic they control is not obvious.

And thus become a potential source of errors themselves when the logic they control is not obvious.

And that's the problem I see about the MISRA ruleset. It is not intended to reduce errors, but to eliminate ambiguities and implementation-specific behavior of C - even at the cost of introducing additional sources of errors and degrading performance significantly.