LANG.STRUCT.CUP : Comparison of Unrelated Pointers

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Pointers to different objects are compared.

Pointer comparison should only be performed between pointers that point at different elements of the same array. Comparing pointers (using <, <=, >, >=) that point at different variables or allocations is undefined behavior according to the C and C++ standards.

Class Name

Comparison of Unrelated Pointers

Significance

reliability

Mnemonic

LANG.STRUCT.CUP

Categories

MisraC2023	MisraC2023:18.3	The relational operators >, >=, < and <= shall not be applied to expressions of pointer type except where they point into the same object
Misra2012	Misra2012:18.3	The relational operators >, >=, < and <= shall not be applied to expressions of pointer type except where they point into the same object
Misra2004	Misra2004:17.3	>, >=, <, <= shall not be applied to pointer types except where they point to the same array
AUTOSARC++14	AUTOSARC++14:M5-0-18	>, >=, <, <= shall not be applied to objects of pointer type, except where they point to the same array.
MisraC++2008	MisraC++2008:5-0-18	> , >= , < , <= shall not be applied to objects of pointer type, except where they point to the same array.
MisraC++2023	MisraC++2023:8.9.1	The built-in relational operators >, >=, < and <= shall not be applied to objects of pointer type, except where they point to elements of the same array
TS17961	TS17961:5.35-ptrobj	5.35. Subtracting or comparing two pointers that do not refer to the same array
CERT-C	CERT-C:ARR36-C	Do not subtract or compare two pointers that do not refer to the same array
	CERT-C:EXP08-C	Ensure pointer arithmetic is used correctly
CERT-CPP	CERT-CPP:CTR54-CPP	Do not subtract iterators that do not refer to the same container
JSF++	JSF++:171	Relational operators shall not be applied to pointer types except where both operands are of the same type and point to the same entity.

Availability

Available for C and C++.

Enabling

Checks for this warning class are enabled by default. To disable them, add the following WARNING_FILTER rule to the project configuration file.

WARNING_FILTER += discard class="Comparison of Unrelated Pointers"

int lang_struct_cup()
{
    int i, j;
    return &i < &j;  /* 'Comparison of Unrelated Pointers' warning issued here */
}

The following configuration file parameters affect checks for this warning class.

LANG.STRUCT.CUP : Comparison of Unrelated Pointers

Summary

Properties

Example

Relevant Configuration File Parameters