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Funtions with parameter of type char as for example \"strcpy\" I can not use signed or unsigned char. Eventhoug the compiler specifies that char is signed, whenever you call strcpy with signed char, there is a compilation error, but if we use the parameter of type char, then we violate rule 14. Does this mean that we must generate our own string manipulation functions?

I have made some presumptions regarding the MISRA 2004 concept of Underlying Type. Do correct me if I am wrong in these presumptions.

1. Explicit casts change an expression's underlying type
2. The Standard is not concerned with an expression's underlying type if any of its sub-expressions violate a required underlying type-related rule
3. Implicitly converting an expression (excluding promotions) change its underlying type
4. Effectively Boolean expressions have underlying type of int (see commentary in MISRA 2004, 6.10.2)
5. Enums and enumerations constants have underlying type of int (see C90 Standard, Clause 3, Section 1, Sub-section 3, Part 3)

Does anyone see a problem with any of these?

Expanding upon the example in the MISRA 2004 Standard for 14.3:


#define WHATABOUTTHIS /* Um */ ;
#define ORTHIS
#define ANDTHISTOO /* Well, I, uh... */

void f()
{
; /* OK */
/* Not OK */ ;
;/* Not OK */
WHATABOUTTHIS
ORTHIS;
ANDTHISTOO;
}

Which of the lines with macros, if any, violate the Rule?

Hi everybody,
did anyone of you try the digests function of this MISRA Bulletin Board ?
It seems to me that I got the message \"no posts\" (as usually :-) )although there was a post in a subforum of the misra-rules-forum on Dec 8 and I don't think I have been logged in since then.
(I selected weekly digest)

Erik

Does Rule 7.1, \"No octal constants (other than zero) and octal escape sequences shall not be used,\" permit the use of the null character, '\\0'? The normative and rule text exempt 0, per se, but make no mention about '\\0'. Prohibitting '\\0' runs, IMHO, contrary to the Principle of Least Surprise. Perhaps someone would show such kindness as to provide me with some clarity?

I appreciate your time in advance.

I was looking through the MISRA 2 Standard and was wondering what the underlying type of an expression is involving mixed types. For example suppose we are given the following variables:
int i1, i2, *ip;
unsigned char uc;
float f;
What is the underlying type of:
i1 | uc;
i2 ? i1 : uc;
&i1;
ip;
( i1 == i2 );
f;
Since the Standard goes into such detail regarding the concept of \"underlying type\", I feel this is an important issue which, to me, requires clarification.

Hi,

I have a few queries with respect to \"dynamic memory allocation\". As per the rule we are not supposed to use functions like \"malloc()\", \"free()\", \"calloc()\" etc. But malloc() is a very common requirement. Most of the embedded system applications use their own application level memory managers so as to make the allocation and de-allocation fast. Do you have any suggestions to get around this problem ( if we can't use malloc, any other way )?

One possible solution I can think of right now it to do a static allocation of a big chunk of memory and redirecting all the dynamic memory requirements to that chunk ( basically a kind of memory manager ). But here also we are stuck with one problem. If we write an application level memory manager, it has to cater to all data types. This will require conversion from any data type to \"void*\" and from \"void*\" to any data type ( say \"char*\" ). But Rule No: 45 of MISRA C ( Typecasting from any type to or from pointers shall not be used ) prohibits me doing that also.

The third problem is with writing portable code. Its quite common to use codes like (X*)0->data1 to get the offset to data1 , where X is a structure ( struct X { }; ) and data1 is a member within that structure. Are we not supposed to use these types of casts too [ (X*)0 ] ???

It would be great if someone could give some possible solutions to these kind of issues.

- Thanks
- Raveendran V.

Hi,

I'd like to know how the corporate PDF Version of the Misra Rules can be used.
How many people can use it at all and at the same time, does it work like a \"floating license\" ?

Thanks,

Erik

Copies of the presentation material from the recent MISRA C technical forum, held on 14 October 2004, are now available.

Visit the \"Resources\" section of the MISRA C website to find them.

Will these be made available?

If so where and when?

Best Regards

Andrzej