MISRA C:2025

Perforce QAC for C 2026.1

(MISRA C:2025 First Edition)

Rule Enforcement Summary

    Total
a Total Number of Rules 223
b Total Number of 'Not Statically Enforceable' Rules (Assisted/Unassisted) 22
c Total Number of Enforceable Rules (a-b) 201
d Total Number of Enforced Rules 201
e Total Number of Unenforced Rules (c-d) 0
f Enforced Rules Percentage (d/c) 100%
g Unenforced Rules Percentage (e/c) 0%

 

Id Description Category Analysis Enforced
Rule-1.1 The program shall contain no violations of the standard C syntax and constraints, and shall not exceed the implementation's translation limits Required Decidable Yes
Rule-1.3 There shall be no occurrence of undefined or critical unspecified behaviour Required Undecidable Yes
Rule-1.4 Emergent language features shall not be used Required Decidable Yes
Rule-1.5 Obsolescent language features shall not be used Required Undecidable Yes
Rule-2.1 A project shall not contain unreachable code Required Undecidable Yes
Rule-2.2 A project shall not contain dead code Required Undecidable Yes
Rule-2.3 A project should not contain unused type declarations Advisory Decidable Yes
Rule-2.4 A project should not contain unused tag declarations Advisory Decidable Yes
Rule-2.5 A project should not contain unused macro definitions Advisory Decidable Yes
Rule-2.6 A function should not contain unused label declarations Advisory Decidable Yes
Rule-2.7 A function should not contain unused parameters Advisory Decidable Yes
Rule-2.8 A project should not contain unused object definitions Advisory Decidable Yes
Rule-3.1 The character sequences /* and // shall not be used within a comment Required Decidable Yes
Rule-3.2 Line-splicing shall not be used in // comments Required Decidable Yes
Rule-4.1 Octal and hexadecimal escape sequences shall be terminated Required Decidable Yes
Rule-4.2 Trigraphs should not be used Advisory Decidable Yes
Rule-5.1 External identifiers shall be distinct Required Decidable Yes
Rule-5.2 Identifiers declared in the same scope and name space shall be distinct Required Decidable Yes
Rule-5.3 An identifier declared in an inner scope shall not hide an identifier declared in an outer scope Required Decidable Yes
Rule-5.4 Macro identifiers shall be distinct Required Decidable Yes
Rule-5.5 Identifiers shall be distinct from macro names Required Decidable Yes
Rule-5.6 A typedef name shall be a unique identifier Required Decidable Yes
Rule-5.7 A tag name shall be a unique identifier Required Decidable Yes
Rule-5.8 Identifiers that define objects or functions with external linkage shall be unique Required Decidable Yes
Rule-5.9 Identifiers that define objects or functions with internal linkage should be unique Advisory Decidable Yes
Rule-5.10 A reserved identifier or reserved macro name shall not be declared Required Decidable Yes
Rule-6.1 Bit-fields shall only be declared with an appropriate type Required Decidable Yes
Rule-6.2 Single-bit named bit fields shall not be of a signed type Required Decidable Yes
Rule-6.3 A bit field shall not be declared as a member of a union Required Decidable Yes
Rule-7.1 Octal constants shall not be used Required Decidable Yes
Rule-7.2 A "u" or "U" suffix shall be applied to all integer constants that are represented in an unsigned type Required Decidable Yes
Rule-7.3 The lowercase character "l" shall not be used in a literal suffix Required Decidable Yes
Rule-7.4 A string literal shall not be assigned to an object unless the object's type is "pointer to const-qualified char" Required Decidable Yes
Rule-7.5 The argument of an integer-constant macro shall have an appropriate form Mandatory Decidable Yes
Rule-7.6 The small integer variants of the minimum-width integer constant macros shall not be used Required Decidable Yes
Rule-8.1 Types shall be explicitly specified Required Decidable Yes
Rule-8.2 Function types shall be in prototype form with named parameters Required Decidable Yes
Rule-8.3 All declarations of an object or function shall use the same names and type qualifiers Required Decidable Yes
Rule-8.4 A compatible declaration shall be visible when an object or function with external linkage is defined Required Decidable Yes
Rule-8.5 An external object or function shall be declared once in one and only one file Required Decidable Yes
Rule-8.6 An identifier with external linkage shall have exactly one external definition Required Decidable Yes
Rule-8.7 Functions and objects should not be defined with external linkage if they are referenced in only one translation unit Advisory Decidable Yes
Rule-8.8 The static storage class specifier shall be used in all declarations of objects and functions that have internal linkage Required Decidable Yes
Rule-8.9 An object should be declared at block scope if its identifier only appears in a single function Advisory Decidable Yes
Rule-8.10 An inline function shall be declared with the static storage class Required Decidable Yes
Rule-8.11 When an array with external linkage is declared, its size should be explicitly specified Advisory Decidable Yes
Rule-8.12 Within an enumerator list, the value of an implicitly-specified enumeration constant shall be unique Required Decidable Yes
Rule-8.13 A pointer should point to a const-qualified type whenever possible Advisory Undecidable Yes
Rule-8.14 The restrict type qualifier shall not be used Required Decidable Yes
Rule-8.15 All declarations of an object with an explicit alignment specification shall specify the same alignment Required Decidable Yes
Rule-8.16 The alignment specification of zero should not appear in an object declaration Advisory Decidable Yes
Rule-8.17 At most one explicit alignment specifier should appear in an object declaration Advisory Decidable Yes
Rule-8.18 There shall be no tentative definitions in a header file Required Decidable Yes
Rule-8.19 There should be no external declarations in a source file Advisory Decidable Yes
Rule-9.1 The value of an object with automatic storage duration shall not be read before it has been set Mandatory Undecidable Yes
Rule-9.2 The initializer for an aggregate or union shall be enclosed in braces Required Decidable Yes
Rule-9.3 Arrays shall not be partially initialized Required Decidable Yes
Rule-9.4 An element of an object shall not be initialized more than once Required Decidable Yes
Rule-9.5 Where designated initializers are used to initialize an array object the size of the array shall be specified explicitly Required Decidable Yes
Rule-9.6 An initializer using chained designators shall not contain initializers without designators Required Decidable Yes
Rule-9.7 Atomic objects shall be appropriately initialized before being accessed Mandatory Undecidable Yes
Rule-10.1 Operands shall not be of an inappropriate essential type Required Decidable Yes
Rule-10.2 Expressions of essentially character type shall not be used inappropriately in addition and subtraction operations Required Decidable Yes
Rule-10.3 The value of an expression shall not be assigned to an object with a narrower essential type or of a different essential type category Required Decidable Yes
Rule-10.4 Both operands of an operator in which the usual arithmetic conversions are performed shall have the same essential type category Required Decidable Yes
Rule-10.5 The value of an expression should not be cast to an inappropriate essential type Advisory Decidable Yes
Rule-10.6 The value of a composite expression shall not be assigned to an object with wider essential type Required Decidable Yes
Rule-10.7 If a composite expression is used as one operand of an operator in which the usual arithmetic conversions are performed then the other operand shall not have wider essential type Required Decidable Yes
Rule-10.8 The value of a composite expression shall not be cast to a different essential type category or a wider essential type Required Decidable Yes
Rule-11.1 Conversions shall not be performed between a pointer to a function and any other type Required Decidable Yes
Rule-11.2 Conversions shall not be performed between a pointer to an incomplete type and any other type Required Decidable Yes
Rule-11.3 A conversion shall not be performed between a pointer to object type and a pointer to a different object type Required Decidable Yes
Rule-11.4 A conversion shall not be performed between a pointer to object and an arithmetic type Advisory Decidable Yes
Rule-11.5 A conversion should not be performed from pointer to void into pointer to object Advisory Decidable Yes
Rule-11.6 A cast shall not be performed between pointer to void and an arithmetic type Required Decidable Yes
Rule-11.8 A conversion shall not remove any const, volatile or _Atomic qualification from the type pointed to by a pointer Required Decidable Yes
Rule-11.9 The macro NULL shall be the only permitted form of integer null pointer constant Required Decidable Yes
Rule-11.10 The _Atomic qualifier shall not be applied to the incomplete type void Required Decidable Yes
Rule-11.11 Pointers shall not be implicitly compared to NULL Required Decidable Yes
Rule-12.1 The precedence of operators within expressions should be made explicit Advisory Decidable Yes
Rule-12.2 The right hand operand of a shift operator shall lie in the range zero to one less than the width in bits of the essential type of the left hand operand Required Undecidable Yes
Rule-12.3 The comma operator should not be used Advisory Decidable Yes
Rule-12.4 Evaluation of constant expressions should not lead to unsigned integer wrap-around Advisory Decidable Yes
Rule-12.5 The sizeof operator shall not have an operand which is a function parameter declared as 'array of type' Mandatory Decidable Yes
Rule-12.6 Structure and union members of atomic objects shall not be directly accessed Required Decidable Yes
Rule-13.1 Initializer lists shall not contain persistent side-effects Required Undecidable Yes
Rule-13.2 The value of an expression and its persistent side-effects shall be the same under all permitted evaluation orders and shall be independent from thread interleaving Required Undecidable Yes
Rule-13.3 A full expression containing an increment (++) or decrement (--) operator should have no other potential side effects other than that caused by the increment or decrement operator Advisory Decidable Yes
Rule-13.4 The result of an assignment operator should not be used Advisory Decidable Yes
Rule-13.5 The right hand operand of a logical && or || operator shall not contain persistent side effects Required Undecidable Yes
Rule-13.6 The operand of the sizeof operator shall not contain any expression which has potential side-effects Required Decidable Yes
Rule-14.1 A loop counter shall not have essentially floating type Required Undecidable Yes
Rule-14.2 A for loop shall be well-formed Required Undecidable Yes
Rule-14.3 Controlling expressions shall not be invariant Required Undecidable Yes
Rule-14.4 The controlling expression of an if-statement and the controlling expression of an iteration-statement shall have essentially Boolean type Required Decidable Yes
Rule-15.1 The goto statement should not be used Advisory Decidable Yes
Rule-15.2 The goto statement shall jump to a label declared later in the same function Required Decidable Yes
Rule-15.3 Any label referenced by a goto statement shall be declared in the same block, or in any block enclosing the goto statement Required Decidable Yes
Rule-15.4 There should be no more than one break or goto statement used to terminate any iteration statement Advisory Decidable Yes
Rule-15.5 A function should have a single point of exit at the end Advisory Decidable Yes
Rule-15.6 The body of an iteration-statement or a selection-statement shall be a compound-statement Required Decidable Yes
Rule-15.7 All if ... else if constructs shall be terminated with an else statement Required Decidable Yes
Rule-16.1 All switch statements shall be well-formed Required Decidable Yes
Rule-16.2 A switch label shall only be used when the most closely-enclosing compound statement is the body of a switch statement Required Decidable Yes
Rule-16.3 Every switch-clause shall be appropriately terminated Required Decidable Yes
Rule-16.4 Every switch statement shall have a default label Required Decidable Yes
Rule-16.5 A default label shall appear as either the first or the last switch label of a switch statement Required Decidable Yes
Rule-16.6 Every switch statement shall have at least two switch-clauses Required Decidable Yes
Rule-16.7 A switch-expression shall not have essentially Boolean type Required Decidable Yes
Rule-17.1 The standard header file <stdarg.h> shall not be used Required Decidable Yes
Rule-17.2 Functions shall not call themselves, either directly or indirectly Required Undecidable Yes
Rule-17.3 A function shall not be declared implicitly Mandatory Decidable Yes
Rule-17.4 All exit paths from a function with non-void return type shall have an explicit return statement with an expression Mandatory Decidable Yes
Rule-17.5 The function argument corresponding to a parameter declared to have an array type shall have an appropriate number of elements Required Undecidable Yes
Rule-17.7 The value returned by a function having non-void return type shall be used Required Decidable Yes
Rule-17.8 A function parameter should not be modified Advisory Undecidable Yes
Rule-17.9 A function declared with a _Noreturn function specifier shall not return to its caller Mandatory Undecidable Yes
Rule-17.10 A function declared with a _Noreturn function specifier shall have void return type Required Decidable Yes
Rule-17.11 A function that never returns should be declared with a _Noreturn function specifier Advisory Undecidable Yes
Rule-17.12 A function identifier should only be used with either a preceding &, or with a parenthesised parameter list Advisory Decidable Yes
Rule-17.13 A function type shall not be type qualified Required Decidable Yes
Rule-18.1 A pointer resulting from arithmetic on a pointer operand shall address an element of the same array as that pointer operand Required Undecidable Yes
Rule-18.2 Subtraction between pointers shall only be applied to pointers that address elements of the same array Required Undecidable Yes
Rule-18.3 The relational operators >, >=, < and <= shall not be applied to expressions of pointer type except where they point into the same object Required Undecidable Yes
Rule-18.4 The +, -, += and -= operators should not be applied to an expression of pointer type Advisory Decidable Yes
Rule-18.5 Declarations should contain no more than two levels of pointer nesting Advisory Decidable Yes
Rule-18.6 The address of an object with automatic or thread-local storage shall not be copied to another object that persists after the first object has ceased to exist Required Undecidable Yes
Rule-18.7 Flexible array members shall not be declared Required Decidable Yes
Rule-18.8 Variable-length arrays shall not be used Required Decidable Yes
Rule-18.9 An object with temporary lifetime shall not undergo array-to-pointer conversion Required Decidable Yes
Rule-18.10 Pointers to variably-modified array types shall not be used Mandatory Decidable Yes
Rule-19.1 An object shall not be assigned or copied to an overlapping object Mandatory Undecidable Yes
Rule-19.2 The union keyword should not be used Advisory Decidable Yes
Rule-19.3 A union member shall not be read unless it has been previously set Required Undecidable Yes
Rule-20.1 #include directives should only be preceded by preprocessor directives or comments Advisory Decidable Yes
Rule-20.2 The ', " or \ characters and the /* or // character sequences shall not occur in a header file name Required Decidable Yes
Rule-20.3 The #include directive shall be followed by either a <filename> or "filename" sequence Required Decidable Yes
Rule-20.4 A macro shall not be defined with the same name as a keyword Required Decidable Yes
Rule-20.5 #undef should not be used Advisory Decidable Yes
Rule-20.6 Tokens that look like a preprocessing directive shall not occur within a macro argument Required Decidable Yes
Rule-20.7 Expressions resulting from the expansion of macro parameters shall be appropriately delimited Required Decidable Yes
Rule-20.8 The controlling expression of a #if or #elif preprocessing directive shall evaluate to 0 or 1 Required Decidable Yes
Rule-20.9 All identifiers used in the controlling expression of #if or #elif preprocessing directives shall be #define'd before evaluation Required Decidable Yes
Rule-20.10 The # and ## preprocessor operators should not be used Advisory Decidable Yes
Rule-20.11 A macro parameter immediately following a # operator shall not immediately be followed by a ## operator Required Decidable Yes
Rule-20.12 A macro parameter used as an operand to the # or ## operators, which is itself subject to further macro replacement, shall only be used as an operand to these operators Required Decidable Yes
Rule-20.13 A line whose first token is # shall be a valid preprocessing directive Required Decidable Yes
Rule-20.14 All #else, #elif and #endif preprocessor directives shall reside in the same file as the #if, #ifdef or #ifndef directive to which they are related Required Decidable Yes
Rule-20.15 #define and #undef shall not be used on a reserved identifier or reserved macro name Required Decidable Yes
Rule-21.3 The memory allocation and deallocation functions of <stdlib.h> shall not be used Required Decidable Yes
Rule-21.4 The standard header file <setjmp.h> shall not be used Required Decidable Yes
Rule-21.5 The standard header file <signal.h> shall not be used Required Decidable Yes
Rule-21.6 The Standard Library input/output functions shall not be used Required Decidable Yes
Rule-21.7 The Standard Library functions atof, atoi, atol and atoll of <stdlib.h> shall not be used Required Decidable Yes
Rule-21.8 The Standard Library functions abort, exit, getenv and system of <stdlib.h> shall not be used Required Decidable Yes
Rule-21.9 The Standard Library functions bsearch and qsort of <stdlib.h> shall not be used Required Decidable Yes
Rule-21.10 The Standard Library time and date functions shall not be used Required Decidable Yes
Rule-21.11 The standard header file <tgmath.h> should not be used Advisory Decidable Yes
Rule-21.12 The standard header file <fenv.h> shall not be used Required Decidable Yes
Rule-21.13 Any value passed to a function in <ctype.h> shall be representable as an unsigned char or be the value EOF Mandatory Undecidable Yes
Rule-21.14 The Standard Library function memcmp shall not be used to compare null terminated strings Required Undecidable Yes
Rule-21.15 The pointer arguments to the Standard Library functions memcpy, memmove and memcmp shall be pointers to qualified or unqualified versions of compatible types Required Decidable Yes
Rule-21.16 The pointer arguments to the Standard Library function memcmp shall point to either a pointer type, an essentially signed type, an essentially unsigned type, an essentially Boolean type or an essentially enum type Required Decidable Yes
Rule-21.17 Use of the string handling functions from <string.h> shall not result in accesses beyond the bounds of the objects referenced by their pointer parameters Mandatory Undecidable Yes
Rule-21.18 The size_t argument passed to any function in <string.h> shall have an appropriate value Mandatory Undecidable Yes
Rule-21.19 The pointers returned by the Standard Library functions lovaleconv, getenv, setlocale or strerror shall only be used as if they have pointer to const-qualified type Mandatory Undecidable Yes
Rule-21.20 The pointer returned by the Standard Library functions asctime, ctime, gmtime, localtime, localeconv, getenv, setlocale, or strerror shall not be used following a subsequent call to the same function Mandatory Undecidable Yes
Rule-21.21 The Standard Library system of <stdlib.h> shall not be used Required Decidable Yes
Rule-21.22 All operand arguments to any type-generic macros declared in <tgmath.h> shall have an appropriate essential type Mandatory Decidable Yes
Rule-21.23 All operand arguments to any multi-argument type-generic macros declared in <tgmath.h> shall have the same standard type Required Decidable Yes
Rule-21.24 The random number generator functions of <stdlib.h> shall not be used Required Decidable Yes
Rule-21.25 All memory synchronization operations shall be executed in sequentially consistent order Required Decidable Yes
Rule-21.26 The Standard Library function mtx_timedlock() shall only be invoked on mutex objects of appropriate mutex type Required Undecidable Yes
Rule-22.1 All resources obtained dynamically by means of Standard Library functions shall be explicitly released Required Undecidable Yes
Rule-22.2 A block of memory shall only be freed if it was allocated by means of a Standard Library function Mandatory Undecidable Yes
Rule-22.3 The same file shall not be open for read and write access at the same time on different streams Required Undecidable Yes
Rule-22.4 There shall be no attempt to write to a stream which has been opened as read-only Mandatory Undecidable Yes
Rule-22.5 A pointer to a FILE object shall not be dereferenced Mandatory Undecidable Yes
Rule-22.6 The value of a pointer to a FILE shall not be used after the associated stream has been closed Mandatory Undecidable Yes
Rule-22.7 The macro EOF shall only be compared with the unmodified return value from any Standard Library function capable of returning EOF Required Undecidable Yes
Rule-22.8 The value of errno shall be set to zero prior to a call to an errno-setting-function Required Undecidable Yes
Rule-22.9 The value of errno shall be tested against zero after calling an errno-setting-function Required Undecidable Yes
Rule-22.10 The value of errno shall only be tested when the last function to be called was an errno-setting-function Required Undecidable Yes
Rule-22.11 A thread that was previously either joined or detached shall not be subsequently joined nor detached Required Undecidable Yes
Rule-22.12 Thread objects, thread synchronization objects, and thread-specific storage pointers shall only be accessed by the appropriate Standard Library functions Mandatory Undecidable Yes
Rule-22.13 Thread objects, thread synchronization objects and thread-specific storage pointers shall have appropriate storage duration Required Decidable Yes
Rule-22.14 Thread synchronization objects shall be initialized before being accessed Mandatory Undecidable Yes
Rule-22.15 Thread synchronization objects and thread-specific storage pointers shall not be destroyed until after all threads accessing them have terminated Required Undecidable Yes
Rule-22.16 All mutex objects locked by a thread shall be explicitly unlocked by the same thread Required Undecidable Yes
Rule-22.17 No thread shall unlock a mutex or call cnd_wait() or cnd_timedwait() for a mutex it has not locked before Required Undecidable Yes
Rule-22.18 Non-recursive mutexes shall not be recursively locked Required Undecidable Yes
Rule-22.19 A condition variable shall be associated with at most one mutex object Required Undecidable Yes
Rule-22.20 Thread-specific storage pointers shall be created before being accessed Mandatory Undecidable Yes
Rule-23.1 A generic selection should only be expanded from a macro Advisory Decidable Yes
Rule-23.2 A generic selection that is not expanded from a macro shall not contain potential side effects in the controlling expression Required Decidable Yes
Rule-23.3 A generic selection should contain at least one non-default association Advisory Decidable Yes
Rule-23.4 A generic association shall list an appropriate type Required Decidable Yes
Rule-23.5 A generic selection should not depend on implicit pointer type conversion Advisory Decidable Yes
Rule-23.6 The controlling expression of a generic selection shall have an essential type that matches its standard type Required Decidable Yes
Rule-23.7 A generic selection that is expanded from a macro should evaluate its argument only once Advisory Decidable Yes
Rule-23.8 A default association shall appear as either the first or the last association of a generic selection Required Decidable Yes

Directive Enforcement

'A directive is a guideline for which it is not possible to provide the Yes description necessary to perform a check for compliance.' MISRA C:2025 Section 6.1. Due to the nature of directives, they are, in theory, not statically enforceable, however, the use of the tools can supply some assistance in checking.

Id Description Assisted Notes
Dir-1.1 Any implementation-defined behaviour on which the output of the program depends shall be documented and understood Assisted
Dir-1.2 The use of language extensions should be minimised Assisted
Dir-2.1 All source files shall compile without any compilation errors Unassisted Not statically enforceable
Dir-3.1 All code shall be traceable to documented requirements Unassisted Not statically enforceable
Dir-4.1 Run-time failures shall be minimized Assisted
Dir-4.2 All usage of assembly language should be documented Assisted
Dir-4.3 Assembly language shall be encapsulated and isolated Assisted
Dir-4.4 Sections of code should not be "commented out" Assisted
Dir-4.5 Identifiers in the same name space with overlapping visibility should be typographically unambiguous Assisted
Dir-4.6 typedefs that indicate size and signedness should be used in place of basic integer types Assisted
Dir-4.7 If a function returns error information, then that error information shall be tested Assisted
Dir-4.8 If a pointer to a structure or union is never dereferenced within a translation unit, then the implementation of the object should be hidden Assisted
Dir-4.9 A function should be used in preference to a function-like macro where they are interchangeable Assisted
Dir-4.10 Precautions shall be taken in order to prevent the contents of a header file being included more than once Assisted
Dir-4.11 The validity of values passed to library functions shall be checked Unassisted
Dir-4.12 Dynamic memory allocation shall not be used Assisted
Dir-4.13 Functions which are designed to provide operations on a resource should be called in an appropriate sequence Assisted
Dir-4.14 The validity of values received from external sources shall be checked Assisted
Dir-4.15 Evaluation of floating-point expressions shall not lead to the undetected generation of infinities and NaNs Unassisted
Dir-5.1 There shall be no data races between threads Assisted
Dir-5.2 There shall be no deadlocks between threads Assisted
Dir-5.3 There shall be no dynamic thread creation Unassisted