<![CDATA[MISRA Discussion Forums - C++ General]]> https://forum.misra.org.uk/ Thu, 05 Nov 2026 13:03:27 +0000 MyBB <![CDATA[Enabling engagement from open source communities]]> https://forum.misra.org.uk/showthread.php?tid=1626 Mon, 04 Jul 2022 09:51:08 +0000 Kim Viggedal]]> https://forum.misra.org.uk/showthread.php?tid=1626
The open source community has been reluctant to try to implement support for checking compliance with previous MISRA C++ Guidelines in static analysis tools because they are not openly published. I'm proposing that it would be of great value to the automotive industry as a whole if MISRA C++ Guidelines were published under a copyright license which explicitly allows free use of the guidelines e.g. for use as a specification for implementing support for the Guidelines in opens source static analysis tools.

Is there anything currently preventing MISRA from taking such an approach to publishing of guidelines?]]>
The open source community has been reluctant to try to implement support for checking compliance with previous MISRA C++ Guidelines in static analysis tools because they are not openly published. I'm proposing that it would be of great value to the automotive industry as a whole if MISRA C++ Guidelines were published under a copyright license which explicitly allows free use of the guidelines e.g. for use as a specification for implementing support for the Guidelines in opens source static analysis tools.

Is there anything currently preventing MISRA from taking such an approach to publishing of guidelines?]]> <![CDATA[MISRA C++ 2008 Example Suite]]> https://forum.misra.org.uk/showthread.php?tid=1479 Fri, 08 Mar 2019 06:24:16 +0000 jungsun.goh]]> https://forum.misra.org.uk/showthread.php?tid=1479 There is only MISRA C related stuff in Resources.
Is there MISRA C ++ 2008 example suites deployment plan?]]> There is only MISRA C related stuff in Resources.
Is there MISRA C ++ 2008 example suites deployment plan?]]> <![CDATA[MISRA C++ Working Group membership]]> https://forum.misra.org.uk/showthread.php?tid=1462 Wed, 16 Jan 2019 22:20:40 +0000 vladisld]]> https://forum.misra.org.uk/showthread.php?tid=1462
1. What is the process of applying for the membership in the C++ Working Group for the company? What are the requirements for such membership ?
2. How often the working group meetings are taking place ?

Thanks
Vlad]]>
1. What is the process of applying for the membership in the C++ Working Group for the company? What are the requirements for such membership ?
2. How often the working group meetings are taking place ?

Thanks
Vlad]]> <![CDATA[Certified C++ Standard Library]]> https://forum.misra.org.uk/showthread.php?tid=1458 Wed, 10 Oct 2018 02:22:12 +0000 dejanpan]]> https://forum.misra.org.uk/showthread.php?tid=1458 https://www.autosar.org/standards/adaptive-platform/. We plan to certify this framework as a Safety Element Out of Context according to ISO 26262.

The framework is written in C++ and makes rather heavy use of constructs implemented in Standard Library (see below for the full list). Many C++ keywords like throw or lambdas use the C++ standard library. So removing the C++ standard library would lead to a dysfunctional compiler.

We are aware of 3 Standard Library implementations:
1. LLVM libc++: https://libcxx.llvm.org/docs/
2. GCC libstdc++: https://gcc.gnu.org/
3. Dinkumware: https://www.dinkumware.com/

Now the problem is that none of the above libraries are certified according to ISO 26262.

Questions:
1. **Are you aware of any ISO 26262 certified Standard Library? Or anybody that is working on it?**
2. **Would any of the above implementations qualify for a “proven in use” argument?**


Constructs in our framework used from the Standard Library:
```cpp
std:Confusedtring
std::vector
std::map
std::unordered_map
std::allocator
std::allocator_traits

std:Confusedhared_ptr
std::make_shared
std::unique_ptr
std::make_unique
std::weak_ptr

std::enable_shared_from_this

std::move

std::ostream
std::ostringstream

std::lock_guard
std::mutex
std:Confusedhared_future
std::thread::hardware_concurrency
std::this_thread::yield()

std::enable_if
std::false_type
std::is_same
std::declval

std::function
std::bind

std::chrono*

std::numeric_limits

std:Confusedhared_future

std::runtime_error
std::invalid_argument

std::int32_t
std::type_index
std:Confusednprintf
```]]> https://www.autosar.org/standards/adaptive-platform/. We plan to certify this framework as a Safety Element Out of Context according to ISO 26262.

The framework is written in C++ and makes rather heavy use of constructs implemented in Standard Library (see below for the full list). Many C++ keywords like throw or lambdas use the C++ standard library. So removing the C++ standard library would lead to a dysfunctional compiler.

We are aware of 3 Standard Library implementations:
1. LLVM libc++: https://libcxx.llvm.org/docs/
2. GCC libstdc++: https://gcc.gnu.org/
3. Dinkumware: https://www.dinkumware.com/

Now the problem is that none of the above libraries are certified according to ISO 26262.

Questions:
1. **Are you aware of any ISO 26262 certified Standard Library? Or anybody that is working on it?**
2. **Would any of the above implementations qualify for a “proven in use” argument?**


Constructs in our framework used from the Standard Library:
```cpp
std:Confusedtring
std::vector
std::map
std::unordered_map
std::allocator
std::allocator_traits

std:Confusedhared_ptr
std::make_shared
std::unique_ptr
std::make_unique
std::weak_ptr

std::enable_shared_from_this

std::move

std::ostream
std::ostringstream

std::lock_guard
std::mutex
std:Confusedhared_future
std::thread::hardware_concurrency
std::this_thread::yield()

std::enable_if
std::false_type
std::is_same
std::declval

std::function
std::bind

std::chrono*

std::numeric_limits

std:Confusedhared_future

std::runtime_error
std::invalid_argument

std::int32_t
std::type_index
std:Confusednprintf
```]]> <![CDATA[Proposal: Consider adding a rule for the undefined behaviour in ISO/IEC 14882:2003 3.6.2 section 3]]> https://forum.misra.org.uk/showthread.php?tid=1449 Wed, 15 Aug 2018 09:16:59 +0000 dg1980]]> https://forum.misra.org.uk/showthread.php?tid=1449
as far as i know, there is no explicit rule to deal with that.
12-8-1 comes close but is for copy constructors only.

An implementation is permitted to perform the initialization of an object of namespace scope with static
storage duration as a static initialization even if such initialization is not required to be done statically, provided
that
— the dynamic version of the initialization does not change the value of any other object of namespace
scope with static storage duration prior to its initialization, and
— the static version of the initialization produces the same value in the initialized object as would be produced
by the dynamic initialization if all objects not required to be initialized statically were initialized
dynamically.
[Note: as a consequence, if the initialization of an object obj1 refers to an object obj2 of namespace
scope with static storage duration potentially requiring dynamic initialization and defined later in the same
translation unit, it is unspecified whether the value of obj2 used will be the value of the fully initialized
obj2 (because obj2 was statically initialized) or will be the value of obj2 merely zero-initialized. For
example,
44
ï›™ ISO/IEC ISO/IEC 14882:2003(E)
3 Basic concepts 3.6.2 Initialization of non-local objects
inline double fd() { return 1.0; }
extern double d1;
double d2 = d1; // unspecified:
// may be statically initialized to 0.0 or
// dynamically initialized to 1.0
double d1 = fd(); // may be initialized statically to 1.0
—end note]
3 It is implementation-defined whether or not the dynamic initialization (8.5, 9.4, 12.1, 12.6.1) of an object of
namespace scope is done before the first statement of main. If the initialization is deferred to some point
in time after the first statement of main, it shall occur before the first use of any function or object defined
in the same translation unit as the object to be initialized.31) [Example:
// – File 1 –
#include "a.h"
#include "b.h"
B b;
A::A(){
b.Use();
}
// – File 2 –
#include "a.h"
A a;
// – File 3 –
#include "a.h"
#include "b.h"
extern A a;
extern B b;
int main() {
a.Use();
b.Use();
}
It is implementation-defined whether either a or b is initialized before main is entered or whether the
initializations are delayed until a is first used in main. In particular, if a is initialized before main is
entered, it is not guaranteed that b will be initialized before it is used by the initialization of a, that is,
before A::A is called. If, however, a is initialized at some point after the first statement of main, b will
be initialized prior to its use in A::A. ]]]>
as far as i know, there is no explicit rule to deal with that.
12-8-1 comes close but is for copy constructors only.

An implementation is permitted to perform the initialization of an object of namespace scope with static
storage duration as a static initialization even if such initialization is not required to be done statically, provided
that
— the dynamic version of the initialization does not change the value of any other object of namespace
scope with static storage duration prior to its initialization, and
— the static version of the initialization produces the same value in the initialized object as would be produced
by the dynamic initialization if all objects not required to be initialized statically were initialized
dynamically.
[Note: as a consequence, if the initialization of an object obj1 refers to an object obj2 of namespace
scope with static storage duration potentially requiring dynamic initialization and defined later in the same
translation unit, it is unspecified whether the value of obj2 used will be the value of the fully initialized
obj2 (because obj2 was statically initialized) or will be the value of obj2 merely zero-initialized. For
example,
44
ï›™ ISO/IEC ISO/IEC 14882:2003(E)
3 Basic concepts 3.6.2 Initialization of non-local objects
inline double fd() { return 1.0; }
extern double d1;
double d2 = d1; // unspecified:
// may be statically initialized to 0.0 or
// dynamically initialized to 1.0
double d1 = fd(); // may be initialized statically to 1.0
—end note]
3 It is implementation-defined whether or not the dynamic initialization (8.5, 9.4, 12.1, 12.6.1) of an object of
namespace scope is done before the first statement of main. If the initialization is deferred to some point
in time after the first statement of main, it shall occur before the first use of any function or object defined
in the same translation unit as the object to be initialized.31) [Example:
// – File 1 –
#include "a.h"
#include "b.h"
B b;
A::A(){
b.Use();
}
// – File 2 –
#include "a.h"
A a;
// – File 3 –
#include "a.h"
#include "b.h"
extern A a;
extern B b;
int main() {
a.Use();
b.Use();
}
It is implementation-defined whether either a or b is initialized before main is entered or whether the
initializations are delayed until a is first used in main. In particular, if a is initialized before main is
entered, it is not guaranteed that b will be initialized before it is used by the initialization of a, that is,
before A::A is called. If, however, a is initialized at some point after the first statement of main, b will
be initialized prior to its use in A::A. ]]]> <![CDATA[C++0x]]> https://forum.misra.org.uk/showthread.php?tid=1325 Wed, 15 Mar 2017 15:06:22 +0000 aviargus]]> https://forum.misra.org.uk/showthread.php?tid=1325 I wanted to know if misra-c++ is going to support c++0x (or at least some of the features)?

Thanks,]]> I wanted to know if misra-c++ is going to support c++0x (or at least some of the features)?

Thanks,]]> <![CDATA[Mixed C/C++ build environment]]> https://forum.misra.org.uk/showthread.php?tid=1284 Tue, 11 Oct 2016 11:40:10 +0000 dg1980]]> https://forum.misra.org.uk/showthread.php?tid=1284 For example, i don't think this is what MISRA intended: http://support.gimpel.com/forums/225702-...th-mixed-c
Also, consider adding exceptions to some rules in the context of headers being included in both C and C++ modules:

Code:
#ifndef FOO_H
#define FOO_H

#define MAGIC_CONSTANT 123456/*Violates MISRA C++ Rule 16-2-2, but is fine in C and changing would require storage in C (effiency)*/
typedef int int32_t;

#ifdef __cplusplus
extern "C"
{
#endif

int32_t foo_api(void);

#ifdef __cplusplus
}
#endif

#endif

Thank you very much.]]> For example, i don't think this is what MISRA intended: http://support.gimpel.com/forums/225702-...th-mixed-c
Also, consider adding exceptions to some rules in the context of headers being included in both C and C++ modules:

Code:
#ifndef FOO_H
#define FOO_H

#define MAGIC_CONSTANT 123456/*Violates MISRA C++ Rule 16-2-2, but is fine in C and changing would require storage in C (effiency)*/
typedef int int32_t;

#ifdef __cplusplus
extern "C"
{
#endif

int32_t foo_api(void);

#ifdef __cplusplus
}
#endif

#endif

Thank you very much.]]> <![CDATA[Code generators for MISRA C++]]> https://forum.misra.org.uk/showthread.php?tid=1220 Mon, 04 Jan 2016 12:55:32 +0000 Insane Vent Storm]]> https://forum.misra.org.uk/showthread.php?tid=1220 <![CDATA[Any upcoming releases for MISRA C++ ?]]> https://forum.misra.org.uk/showthread.php?tid=1195 Tue, 21 Jul 2015 09:53:48 +0000 daniel tuchscherer]]> https://forum.misra.org.uk/showthread.php?tid=1195
As far as I know the latest guideline for C++ is MISRA C++ 2008. According to the current Cpp conferences and its talks about modern C++, the increasing use of embedded linux and during some research C++11 / C++14 both provide many techniques that could be useful for embedded programming of safety critical systems. Please correct me if I'm wrong. To name a few features there are std::array, range-loops, constexpr, static_assert, enum class.

Are there any upcoming MISRA C++ guidelines planned in the near future covering those (C++11, …) standards ?

Thanks Daniel]]>
As far as I know the latest guideline for C++ is MISRA C++ 2008. According to the current Cpp conferences and its talks about modern C++, the increasing use of embedded linux and during some research C++11 / C++14 both provide many techniques that could be useful for embedded programming of safety critical systems. Please correct me if I'm wrong. To name a few features there are std::array, range-loops, constexpr, static_assert, enum class.

Are there any upcoming MISRA C++ guidelines planned in the near future covering those (C++11, …) standards ?

Thanks Daniel]]> <![CDATA[MISRA Rules Ambiguity]]> https://forum.misra.org.uk/showthread.php?tid=1139 Tue, 23 Dec 2014 20:59:43 +0000 igor.gvero]]> https://forum.misra.org.uk/showthread.php?tid=1139 NOTE: THESE ARE NOT SECTION 6 INQUIRIES - SO I AM POSTING THE QUESTIONS HERE

1. Concerning the Rule 5-0-15 of the MISRA C++ 2008 standard, is the following example compliant with the rule?

struct Bar
{
int32_t* dataP[2];
};

void f()
{
int32_t myarray[10];
Bar b;
b.dataP[0] = myarray;
b.dataP[1] = myarray;

int32_t c = (b.dataP[1])[3]; // Is this expression compliant with the rule 5-0-15?
}

The reason that I am asking this question is that the examples for the rule 5-0-15 seem to be contradictory about the use of pointers as arrays. For example, the following are examples from the documentation of the rule 5-0-15:

void my_fn(uint8_t * p1, uint8_t * p2[ ])
{
...
p1[ 5 ] = 0; // Non-compliant – p1 was not declared as array
...
}

uint8_t a[ 10 ];
uint8_t * p;
p = a;
p[ 5 ] = 0; // Compliant : seems to be contradictory with the previous example where it is non-compliant.

I would appreciate if you could explain the exact rule for the use of pointers as arrays in your answer.


2. Concerning the Rule 2-10-2 of the MISRA C++ 2008 standard, is operator overloading allowed for this rule? I think it should be allowed, but I would like to be sure. The rule discuss about identifiers. An operator name should not be an identifier, thus operator overloading should be allowed, but it is not clear from the rule. For example, is the following example compliant with the rule?

#include
#include

namespace myNamespace {
class myClass {
public:
static void* operator new(size_t); // Is this operator overloading compliant with rule 2-10-2?
};
}


3. Concerning the Rule 5-0-2 of the MISRA C++ 2008 standard, can one use parentheses for the operand of the sizeof operator? The rule states that “Parentheses are not required for the operand of a unary operator”. Sizeof is unary operator, thus parentheses should not be required. However, it is common practice to use parentheses with this operator (and even some MISRA examples use this style like rule 5-3-4). Here are some examples to help understand my question:

uint8_t* a = ...;

sizeof *a; // Should be compliant with the rule.
sizeof (int); // Should be compliant with the rule too since the operand is a cast.

sizeof(*a); // This is the one that I am not sure of. I think that it should be accepted but the rule seems to say otherwise.]]> NOTE: THESE ARE NOT SECTION 6 INQUIRIES - SO I AM POSTING THE QUESTIONS HERE

1. Concerning the Rule 5-0-15 of the MISRA C++ 2008 standard, is the following example compliant with the rule?

struct Bar
{
int32_t* dataP[2];
};

void f()
{
int32_t myarray[10];
Bar b;
b.dataP[0] = myarray;
b.dataP[1] = myarray;

int32_t c = (b.dataP[1])[3]; // Is this expression compliant with the rule 5-0-15?
}

The reason that I am asking this question is that the examples for the rule 5-0-15 seem to be contradictory about the use of pointers as arrays. For example, the following are examples from the documentation of the rule 5-0-15:

void my_fn(uint8_t * p1, uint8_t * p2[ ])
{
...
p1[ 5 ] = 0; // Non-compliant – p1 was not declared as array
...
}

uint8_t a[ 10 ];
uint8_t * p;
p = a;
p[ 5 ] = 0; // Compliant : seems to be contradictory with the previous example where it is non-compliant.

I would appreciate if you could explain the exact rule for the use of pointers as arrays in your answer.


2. Concerning the Rule 2-10-2 of the MISRA C++ 2008 standard, is operator overloading allowed for this rule? I think it should be allowed, but I would like to be sure. The rule discuss about identifiers. An operator name should not be an identifier, thus operator overloading should be allowed, but it is not clear from the rule. For example, is the following example compliant with the rule?

#include
#include

namespace myNamespace {
class myClass {
public:
static void* operator new(size_t); // Is this operator overloading compliant with rule 2-10-2?
};
}


3. Concerning the Rule 5-0-2 of the MISRA C++ 2008 standard, can one use parentheses for the operand of the sizeof operator? The rule states that “Parentheses are not required for the operand of a unary operator”. Sizeof is unary operator, thus parentheses should not be required. However, it is common practice to use parentheses with this operator (and even some MISRA examples use this style like rule 5-3-4). Here are some examples to help understand my question:

uint8_t* a = ...;

sizeof *a; // Should be compliant with the rule.
sizeof (int); // Should be compliant with the rule too since the operand is a cast.

sizeof(*a); // This is the one that I am not sure of. I think that it should be accepted but the rule seems to say otherwise.]]> <![CDATA[Abandoned?]]> https://forum.misra.org.uk/showthread.php?tid=1101 Mon, 25 Aug 2014 16:31:21 +0000 gs]]> https://forum.misra.org.uk/showthread.php?tid=1101 <![CDATA[Need for Both C and C++ Guidelines?]]> https://forum.misra.org.uk/showthread.php?tid=887 Mon, 05 Mar 2012 16:10:48 +0000 bmbrown]]> https://forum.misra.org.uk/showthread.php?tid=887 <![CDATA[Exemplar suite for C++]]> https://forum.misra.org.uk/showthread.php?tid=707 Fri, 19 Feb 2010 15:20:40 +0000 azukich]]> https://forum.misra.org.uk/showthread.php?tid=707
Thank you]]>
Thank you]]> <![CDATA[Similarities and differences between Misra C++ and ECPP]]> https://forum.misra.org.uk/showthread.php?tid=559 Tue, 22 Jul 2008 17:02:06 +0000 gfinlay]]> https://forum.misra.org.uk/showthread.php?tid=559 http://www.caravan.net/ec2plus/)? Is there any difference in emphasis or goals of the two projects - e.g. safety critical vs tailoring for resource-limited systems? Perhaps this could be added to the Misra-C++ FAQ. I have used ECPP in a couple of projects with the Freescale Codewarrior C++ compiler (Coldfire version has compiler switches which turn on a EC++ subset).

Gord Finlay]]> http://www.caravan.net/ec2plus/)? Is there any difference in emphasis or goals of the two projects - e.g. safety critical vs tailoring for resource-limited systems? Perhaps this could be added to the Misra-C++ FAQ. I have used ECPP in a couple of projects with the Freescale Codewarrior C++ compiler (Coldfire version has compiler switches which turn on a EC++ subset).

Gord Finlay]]> <![CDATA[Misra C Cross Reference]]> https://forum.misra.org.uk/showthread.php?tid=537 Tue, 17 Jun 2008 08:07:17 +0000 IanStroud]]> https://forum.misra.org.uk/showthread.php?tid=537
We have just purchased a copy of the Misra-C++ Guideline. Not surprisingly there is a lot of commonality with the Misra C guidelines but the rules have different numbers.

Is there a document that cross references the Rules between the two guidelines. In particular I would like to know:
-those rules in Misra C that do not appear in Misra C++
-those rules in Misra C++ that do not appear in Misra C
-rules that are common to both but have been amended slightly in the C++ guidelines

We have spent a lot of time going through the Misra C document seeing which Rules we think are worth adopting into our general coding standards and now wish to do the same with C++. Having a some cross reference would greatly assist this process.

thanks]]>
We have just purchased a copy of the Misra-C++ Guideline. Not surprisingly there is a lot of commonality with the Misra C guidelines but the rules have different numbers.

Is there a document that cross references the Rules between the two guidelines. In particular I would like to know:
-those rules in Misra C that do not appear in Misra C++
-those rules in Misra C++ that do not appear in Misra C
-rules that are common to both but have been amended slightly in the C++ guidelines

We have spent a lot of time going through the Misra C document seeing which Rules we think are worth adopting into our general coding standards and now wish to do the same with C++. Having a some cross reference would greatly assist this process.

thanks]]>