Welcome to the MISRA discussion forum

1998 Rule 29 states, \"[i]t would be incorrect to initialize the tag with an initializer which did not match the structure declared for that tag.\"

What does it mean to \"initialize the tag\"?

Hello,

I am new to MISRA-C rules and in the code I am working on, there this kind of constructs :

I'm working with some legacy code and part of my job is to modify it to comply with the MISRA standard. A large portion of the code relies on macros such as this one:

[code]#define CURRENT_LARGE_SHIFT (18L)
#define CURRENT_LARGE_SCALE(v) (int32_t)(v * (1L

In misraC-2004 when starts section 6.11 - Pointer type Conversion says the following:

\"Conversions involving pointer types require an explicit cast except when:
The conversion is between a pointer to object an a pointer to void....\"

my question is if this example is compliance with that.

Just wondering what is the best way to define a boolean type for MISRA and most importantly what to define TRUE and FALSE as.

Some thoughts:

typedef unsigned char boolean_t
#define TRUE (0==0)
#define FALSE (!0)

Thanks.

Is there a template of the required Compliance Matrix available?

I would like to see such a matrix include the rule synopsis as well as it's ID, so that it is easy to comprehend.

Having purchased the MISRA-C 2004 PDF, I find that it is protected such that I cannot copy the contents of Appendix A as a good starting point.

Regards
Dave Banham

Hi,

I have a question regarding the use of Void pointers.

Rule 11.2 is the rule that applies (Conversions shall not be performed between a pointer to object and any type other than an integral type, another pointer to object or a pointer to void).

My first question is:
How do you define \"a pointer to object\"?
By this, do you mean structure, derived types?
I couldn't see any definition for this in the MISRA text.

My second question is:
This rule allows the conversion of a pointer from one type to void. (i.e. to a NULL_PTR to allow for error checking)
I think that this rule also prohibits the use of a defined void ptr, converting this to point to an array or other obect, is this correct?

i.e. the following is illegal:

void *pv_my_void_ptr = NULL_PTR;
u16 *pu16_my_int_ptr = (u16 *)pv_my_void_ptr;

As this would make the checking of alignment (i.e. Rule 11.4) impossible as well as hiding the original type pointed to?

Many Thanks for your consideration.

Mike.

I am working as a Software Quality Engineer at Siemens VDO in France and we are currently trying to document the consequence(s) of not respecting each of the MISRA rules, in order to make our developers aware of the risk(s). Sometimes this task is quite easy and sometimes less. So I am looking for some documentation that could help us reaching our objective. Today we are still using MISRA 1998, so I am more interested in documents dealing with the correponding rules, but it would also help for the future if some documents on MISRA 2004 exist.

Thanks for Help,

NM

MISRA has been developing a set of guidelines for users of control system modelling packages. The aim of the guidelines is to provide a set of rules, in a similar fashion to the MISRA C rules, which encourage good modelling practices and avoid poorly-defined features of the modelling language. In light of automotive industry trends, some rules will be aimed at the use of automatic code generators in safety-related systems.

Following the initial activities of this Working Group, MISRA is pleased to announce that drafts of the first documents will be available in the new year for public comment. These documents are:

• MISRA SLSF - guidelines for users of Simulink and Stateflow
  
• MISRA TL - guidelines for users of Targetlink
  
• MISRA ACG - guidelines for compliance with MISRA C in automatically-generated code

hello all,

can you anyone provide me some documents related to MISRA C rules

thanks