Fix MISRA C++ 2023 rule 6.7.1 "Local variables shall not have static storage duration"

[mohammedRafeeque]

Zserio version and language
Zserio: latest from master
Commit date: 6 days ago (6/4/2024 7:12:28 PM)
Commit hash: b8cc6c0

Describe the bug
2 Misra warnings are getting reported for rule MISRACPP2023-6_7_1-a

1 static MemoryResource* defaultResource = getNewDeleteResource();
2 static detail::NewDeleteResource newDeleteResource;

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1336	MISRACPP2023-6_7_1-a	2	Do not declare the 'newDeleteResource' local variable with static storage duration	zserio_runtime/zserio/pmr/NewDeleteResource.cpp	10
1335	MISRACPP2023-6_7_1-a	2	Do not declare the 'defaultResource' local variable with static storage duration	zserio_runtime/zserio/pmr/MemoryResource.cpp	17

Please check possibility of fixing the same.

Steps to reproduce the behavior:
SCA run using MISRA 2023 configuration.

Expected behavior
No SCA warnings for MISRA 2023 ruleset

Additional context
N.A

@Roland-Homeier @mikir FYI.

[mohammedRafeeque]

Observation : We cannot remove static as the function returning a reference . Can we declare static variable in .h file within class scope to have single instance ?
MemoryResource* getNewDeleteResource() noexcept
{
static detail::NewDeleteResource newDeleteResource;
return &newDeleteResource;
}

[Mi-La]

I'm afraid that we could get into problems with initialization of such static class variable. This way we ensure that get_default_resource returns pointer to already initialized resource even when it's used before main.

[Mi-La]

Note that Sonar rule M23_233 is enabled and we have 3 accepted issues as an exceptions:

Moudle	Line	Command	Link
AnyHolder.h	29	static int currentTypeId;	SonarCloud
MemoryResource.cpp	17	static MemoryResource* defaultResource = getNewDeleteResource();	SonarCloud
NewDeleteResource.cpp	10	static detail::NewDeleteResource newDeleteResource;	SonarCloud