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Hello

I have a disagreement with a supporter of a bigger MISRA-C:2004 rule checking tool.

He means, that the following is MISRA-C:2004 compliant :

Hi

In Rule 12.2

Quote:nested assignment statements
Assignments nested within expressions cause additional side effects. The best way to avoid any chance of this leading to a dependence on order of evaluation is to not embed assignments within expressions.

For example, the following is not recommended:
x = y = y = z / 3 ;
x = y = y++;

My question is if the code bellow is not compliance with misrac-2004

uint16_t GetSpeed (void);
void IncreaseSpeed (void);
void DecreaseSpeed (void);
void GoodSpeed (void);

enum tagSPEED
{
Low,
Medium,
High
};

void main (void)
{
uint16_t uSpeed;

uSpeed = GetSpeed();

switch (uSpeed)
{
case Low:
IncreaseSpeed();
break;

case Medium:
GoodSpeed (void);
break;

case High:
DecreaseSpeed (void);
break;

default:
break;
}
}

Is there any solution for this case?


Normative reference:
Ansi-Iso-9899-1990 (6.5.2.2)
Misra-c2004 (6.10.3)

I just want to know when a cast shall be performed between a pointer to void and any type or vice versa?

for example is this code compliance with misra-c?

void* GetNewObject (void);
void SetProperty (void*, uint8_t);

void main (void)
{
void* lpVoid;
OBJECT_T* lpObject;

lpVoid = NULL;
lpObject = NULL;

lpObject = GetNewObject ();
/* there is an explicit cast in
this function from OBJECT_T*
type to void* type, so GetNewObject
return an OBJECT_T* qualifier type */

lpVoid = lpObject;

SetProperty (lpVoid, 4U);

lpObject = lpVoid;

if (lpObject == lpVoid)
{
SetProperty (lpObject, 5U);
}

lpVoid = lpObject;
}

My question is why my code test program (lint) generate an error when read this line.

U16 u16value;
U8 u8value;

u16value = (U16) u8value / 10U;

I think that line is absolutly compliance with misrac.

but in other hand this other line does not generate an error, but i think that it is not misra compliance.

U16 u16value;
U8 u8value;

u8value = (U16) u8value / (U16)10U;

I would like to know how to represent a Violation of rule 12.12.
It is stated in C90 that bitwise operands are required to of integer type. Therefore bitwise operators can't be used with floats to demonstrate this rule as this would be a direct violation of rule 1.1.

Is maybe pointer indirection using an unsigned char the answer?

or are there implementations that allow bitwise operators to be used with floats?

Thanks for your help!

Hello,

I use a tool, which tested code to MISRA-C:2004 compliance.

Here is a code example, on which our analyse tool says, there is a breach of rule 21.1.

Hello

I use unions in the following example. And I want to know, if in such a situation the use of unions is compliant or not compliant to MISRA-C:2004. Or if somebody has a better idea for a good implementation.

Hi

Two questions about this rule:

1. Have somebody examples short for function-like macros?
2. When is a macro funktion-like?

best regards,
Manni

Hi

Question about Rule 12.9: The unary minus operator shall not be applied to an expression whose underlying type is unsigned.