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MISRA C:2012 Compliance Summary Tables

MathWorks® evaluates C code generated by Embedded Coder® from Simulink® models and Stateflow® charts against the MISRA C:2012 coding standards. The results from this effort are available in these compliance summary tables. These tables also identifies methods used to obtain compliance:

  • Compliant: Compliance to the rule/directive is achieved through adherence to the code generation process, modeling guidelines, or Model Advisor checks. When applicable, there are explanatory notes that provide information relevant to compliance methods or actions that you can perform to satisfy the directive or rule.

  • Deviation: The rule or directive is not compliant.

You can use these tables when preparing the MISRA C:2012 compliance statement for your project as required per section 5.3 of the MISRA C:2012 Guidelines for the Use of C Language in Critical Systems document. These tables align with the published MISRA C:2012 Main Document, MISRA C:2012 Amendment 1, and MISRA C:2012 Amendment 2. The categories in the table are based on Appendix E of the MISRA guidelines identified for automatically generated code. They can be used for mandatory and required categories only (not for advisory and readability categories).


The generated code from Embedded Coder is compliant with a large subset of these coding guidelines. The noncompliant status of a rule/directive in these tables does not come under mandatory and required categories identified for automatically generated code.

"Implementation" MISRA C:2012 Directives

D1.1Any implementation-defined behaviour on which the output of the program depends shall be documented and understood.Required


"Compilation and Build" MISRA C:2012 Directives

D2.1All source files shall compile without any compilation errors.RequiredCompliant

"Requirements Traceability" MISRA C:2012 Directives

D3.1All code shall be traceable to documented requirements.Required


"Code Design" MISRA C:2012 Directives

D4.1Run-time failures shall be minimized.Required


D4.3Assembly language shall be encapsulated and isolated.Required


D4.6typedefs that indicate size and signedness should be used in place of the basic numerical types.Advisory

Not Applicable.

D4.7bIf a function returns error information, then that error information shall be tested.Required



D4.10Precautions shall be taken in order to prevent the contents of a header file being included more than once.RequiredCompliant
D4.11The validity of values passed to library functions shall be checked.Required


D4.12Dynamic memory allocation shall not be used.Required


D4.14The validity of values received from external sources shall be checked.RequiredCompliant

a Directive 4.14 is from MISRA Amendment 1.

b The Polyspace MISRA C:2012 Checker might flag Directive 4.7 as a Rule 17.7 violation (Polyspace Bug Finder) for user-defined functions when there is no knowledge about whether the return value contains error information.

"Standard C Environment" MISRA C:2012 Rules

1.1The program shall contain no violations of the standard C syntax and constraints, and shall not exceed the implementation's translation limits.RequiredCompliant
1.3There shall be no occurrence of undefined or critical unspecified behaviour.RequiredCompliant
1.4Emergent language features shall not be used.RequiredCompliant

a Rule 1.4 is from MISRA Amendment 2.

"Unused Code" MISRA C:2012 Rules

2.1A project shall not contain unreachable code.Required


2.2There shall be no dead code.RequiredCompliant

"Comments" MISRA C:2012 Rules

3.1The character sequences /* and // shall not be used within a comment.Required


3.2Line-splicing shall not be used in // comments.RequiredCompliant

"Character Sets and Lexical Conventions" MISRA C:2012 Rules

4.1Octal and hexadecimal escape sequences shall be terminated.RequiredCompliant

"Identifiers" MISRA C:2012 Rules

5.1External identifiers shall be distinct.Required


5.2Identifiers declared in the same scope and name space shall be distinct.Required


5.3An identifier declared in an inner scope shall not hide an identifier declared in an outer scope.AdvisoryNoncompliant
5.4Macro identifiers shall be distinct.Required


5.5Identifiers shall be distinct from macro names.Required


5.6A typedef name shall be a unique identifier.Required


5.7A tag name shall be a unique identifier.Required


5.8Identifiers that define objects or functions with external linkage shall be unique.Required


a Guideline identifies Rule 5.3 as Required for manually generated code.

"Types" MISRA C:2012 Rules

6.1Bit-fields shall only be declared with an appropriate type.Required


6.2Single-bit named bit fields shall not be of a signed type.Required


"Literals and Constants" MISRA C:2012 Rules

7.1Octal constants shall not be used.AdvisoryCompliant
7.2A "u" or "U" suffix shall be applied to all integer constants that are represented in an unsigned type.ReadabilityCompliant
7.3The lowercase character "l" shall not be used in a literal suffix.ReadabilityCompliant
7.4A string literal shall not be assigned to an object unless the object's type is "pointer to const-qualified char".RequiredCompliant

a Guideline identifies Rule 7.1, 7.2, and 7.3 as Required for manually generated code.

"Declarations and Definitions" MISRA C:2012 Rules

8.1Types shall be explicitly specified.RequiredCompliant
8.2Function types shall be in prototype form with named parameters.RequiredCompliant
8.3All declarations of an object or function shall use the same names and type qualifiers.RequiredCompliant
8.4A compatible declaration shall be visible when an object or function with external linkage is defined.AdvisoryNoncompliant
8.5An external object or function shall be declared once in one and only one file.AdvisoryNoncompliant
8.6An identifier with external linkage shall have exactly one external definition.RequiredCompliant
8.8The static storage class specifier shall be used in all declarations of objects and functions that have internal linkage.RequiredCompliant
8.10An inline function shall be declared with the static storage class.RequiredCompliant
8.12Within an enumerator list, the value of an implicitly-specified enumeration constant shall be unique.Required


8.14The restrict type qualifier shall not be used.AdvisoryCompliant

a Guideline identifies Rule 8.4, 8.5, and 8.14 as Required for manually generated code.

"Initialization" MISRA C:2012 Rules

9.1The value of an object with automatic storage duration shall not be read before it has been set.Mandatory


9.2The initializer for an aggregate or union shall be enclosed in braces.ReadabilityNoncompliant
9.3Arrays shall not be partially initialized.ReadabilityNoncompliant
9.4An element of an object shall not be initialized more than once.RequiredCompliant
9.5Where designated initializers are used to initialize an array object the size of the array shall be specified explicitly.ReadabilityCompliant

a Guideline identifies Rule 9.2, 9.3, and 9.5 as Required for manually generated code.

"The Essential Type Model" MISRA C:2012 Rules

10.1Operands shall not be of an inappropriate essential type.AdvisoryNoncompliant
10.2Expressions of essentially character type shall not be used inappropriately in addition and subtraction operations.AdvisoryCompliant
10.3The value of an expression shall not be assigned to an object with a narrower essential type or of a different essential type category.AdvisoryCompliant
10.4Both operands of an operator in which the usual arithmetic conversions are performed shall have the same essential type category.AdvisoryNoncompliant
10.6The value of a composite expression shall not be assigned to an object with wider essential type.AdvisoryNoncompliant
10.7If 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.AdvisoryNoncompliant
10.8The value of a composite expression shall not be cast to a different essential type category or a wider essential type.AdvisoryNoncompliant

a Guideline identifies Rule 10.1, 10.2, 10.3, 10.4, 10.6, 10.7, and 10.8 as Required for manually generated code.

"Pointer Type Conversion" MISRA C:2012 Rules

11.1Conversions shall not be performed between a pointer to a function and any other type.RequiredCompliant
11.2Conversions shall not be performed between a pointer to an incomplete type and any other type.RequiredCompliant
11.3A cast shall not be performed between a pointer to object type and a pointer to a different object type.Required


11.6A cast shall not be performed between pointer to void and an arithmetic type.RequiredCompliant
11.7A cast shall not be performed between pointer to object and a non-integer arithmetic type.RequiredCompliant
11.8A cast shall not remove any const or volatile qualification from the type pointed to by a pointer.Required


11.9The macro NULL shall be the only permitted form of integer null pointer constant.ReadabilityNoncompliant

a Guideline identifies Rule 11.9 as Required for manually generated code.

"Expressions" MISRA C:2012 Rules

12.2The 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. RequiredCompliant
12.5The sizeof operator shall not have an operand which is a function parameter declared as "array of type".MandatoryCompliant

a Rule 12.5 is from MISRA Amendment 1.

"Side Effects" MISRA C:2012 Rules

13.1Initializer lists shall not contain persistent side effects.RequiredCompliant
13.2The value of an expression and its persistent side effects shall be the same under all permitted evaluation orders.Required


13.5The right hand operand of a logical && or || operator shall not contain persistent side effects.Required



13.6The operand of the sizeof operator shall not contain any expression which has potential side effects.MandatoryCompliant

"Control Statement Expressions" MISRA C:2012 Rules

14.1A loop counter shall not have essentially floating type.AdvisoryNoncompliant
14.2A for loop shall be well-formed.Readability


14.3Controlling expressions shall not be invariant.Required


14.4The controlling expression of an if statement and the controlling expression of an iteration-statement shall have essentially Boolean type.AdvisoryNoncompliant

a Guideline identifies Rule 14.1, 14.2, and 14.4 as Required for manually generated code.

"Control Flow" MISRA C:2012 Rules

15.2The goto statement shall jump to a label declared later in the same function.AdvisoryCompliant
15.3Any label referenced by a goto statement shall be declared in the same block, or in any block enclosing the goto statement.AdvisoryCompliant
15.6The body of an iteration-statement or a selection-statement shall be a compound-statement.RequiredCompliant
15.7All if ... else if constructs shall be terminated with an else statement.ReadabilityCompliant

a Guideline identifies Rule 15.2, 15.3, and 15.7 as Required for manually generated code.

"Switch statements" MISRA C:2012 Rules

16.1All switch statements shall be well-formed.AdvisoryNoncompliant
16.2A switch label shall only be used when the most closely-enclosing compound statement is the body of a switch statement.AdvisoryCompliant
16.3An unconditional break statement shall terminate every switch-clause.AdvisoryCompliant
16.4Every switch statement shall have a default label.Advisory


16.5A default label shall appear as either the first or the last switch label of a switch statement.AdvisoryCompliant
16.6Every switch statement shall have at least two switch-clauses.AdvisoryCompliant
16.7A switch-expression shall not have essentially Boolean type.AdvisoryCompliant

a Guideline identifies Rule 16.1, 16.2, 16.3, 16.4, 16.5, 16.6, and 16.7 as Required for manually generated code.

"Functions" MISRA C:2012 Rules

17.1The features of <stdarg.h> shall not be used.RequiredCompliant
17.2Functions shall not call themselves, either directly or indirectly.Required


17.3A function shall not be declared implicitly.MandatoryCompliant
17.4All exit paths from a function with non-void return type shall have an explicit return statement with an expression.MandatoryCompliant
17.6The declaration of an array parameter shall not contain the static keyword between the [ ].MandatoryCompliant
17.7The value returned by a function having non-void return type shall be used.ReadabilityNoncompliant

a Guideline identifies Rule 17.7 as Required for manually generated code.

"Pointers and Arrays" MISRA C:2012 Rules

18.1A pointer resulting from arithmetic on a pointer operand shall address an element of the same array as that pointer operand.RequiredCompliant
18.2Subtraction between pointers shall only be applied to pointers that address elements of the same array.RequiredCompliant
18.3The relational operators >, >=, < and <= shall not be applied to objects of pointer type except where they point into the same object.RequiredCompliant
18.6The address of an object with automatic storage shall not be copied to another object that persists after the first object has ceased to exist.RequiredCompliant
18.7Flexible array members shall not be declared.RequiredCompliant
18.8Variable-length array types shall not be used.RequiredCompliant

"Overlapping Storage" MISRA C:2012 Rules

19.1An object shall not be assigned or copied to an overlapping object.MandatoryCompliant

"Preprocessing Directives" MISRA C:2012 Rules

20.2The ', " or \ characters and the /* or // character sequences shall not occur in a header file name.RequiredCompliant
20.3The #include directive shall be followed by either a <filename> or "filename"sequence.RequiredCompliant
20.4A macro shall not be defined with the same name as a keyword.RequiredCompliant
20.6Tokens that look like a preprocessing directive shall not occur within a macro argument.RequiredCompliant
20.7Expressions resulting from the expansion of macro parameters shall be enclosed in parentheses.RequiredCompliant
20.8The controlling expression of a #if or #elif preprocessing directive shall evaluate to 0 or 1.RequiredCompliant
20.9All identifiers used in the controlling expression of #if or #elif preprocessing directives shall be #define'd before evaluation.RequiredCompliant
20.11A macro parameter immediately following a # operator shall not immediately be followed by a ## operator.RequiredCompliant
20.12A 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.RequiredCompliant
20.13A line whose first token is # shall be a valid preprocessing directive.RequiredCompliant
20.14All #else, #elif and #endif preprocessor directives shall reside in the same file as the #if, #ifdef or #ifndef directive to which they are related.RequiredCompliant

"Standard Libraries" MISRA C:2012 Rules

Rulea, bDescriptionCategoryCompliance
21.1#define and #undef shall not be used on a reserved identifier or reserved macro name.Required


21.2A reserved identifier or reserved macro name shall not be declared.Required


21.3The memory allocation and deallocation functions of <stdlib.h> shall not be used.Required


21.4The standard header file <setjmp.h> shall not be used.RequiredCompliant
21.5The standard header file <signal.h> shall not be used.RequiredCompliant
21.6The Standard Library input/output functions shall not be used.Required


21.7The Standard Library functions atof, atoi, atol and atoll of <stdlib.h> shall not be used.RequiredCompliant
21.8The Standard Library termination functions of <stdlib.h> shall not be used.RequiredCompliant
21.9The Standard Library functions bsearch and qsort of <stdlib.h> shall not be used.RequiredCompliant
21.10The Standard Library time and date functions shall not be used.RequiredCompliant
21.11The standard header file <tgmath.h> shall not be used.RequiredCompliant
21.13Any value passed to a function in <ctype.h> shall be representable as an unsigned char or be the value EOF.MandatoryCompliant
21.14The Standard Library function memcmp shall not be used to compare null terminated strings.RequiredCompliant
21.15The pointer arguments to the Standard Library functions memcpy, memmove and memcmp shall be pointers to qualified or unqualified versions of compatible types.RequiredCompliant
21.16The 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.RequiredCompliant
21.17Use of the string handling functions from <string.h> shall not result in accesses beyond the bounds of the objects referenced by their pointer parameters.MandatoryCompliant
21.18The size_t argument passed to any function in <string.h> shall have an appropriate value.MandatoryCompliant
21.19The pointers returned by the Standard Library functions localeconv, getenv, setlocale or, strerror shall only be used as if they have pointer to const-qualified type.MandatoryCompliant
21.20The 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.MandatoryCompliant
21.21The Standard Library function system of <stdlib.h> shall not be used.RequiredCompliant

a Rule 21.13, 21.14, 21.15, 21.16, 21.17, 21.18, 21.19, 21.20 is from MISRA Amendment 1.

b Rule 21.21 is from MISRA Amendment 2.

"Resources" MISRA C:2012 Rules

22.1All resources obtained dynamically by means of Standard Library functions shall be explicitly released.RequiredCompliant
22.2A block of memory shall only be freed if it was allocated by means of a Standard Library function.MandatoryCompliant
22.3The same file shall not be open for read and write access at the same time on different streams.RequiredCompliant
22.4There shall be no attempt to write to a stream which has been opened as read-only.MandatoryCompliant
22.5A pointer to a FILE object shall not be dereferenced.MandatoryCompliant
22.6The value of a pointer to a FILE shall not be used after the associated stream has been closed.MandatoryCompliant
22.7The macro EOF shall only be compared with the unmodified return value from any Standard Library function capable of returning EOF.RequiredCompliant
22.8The value of errno shall be set to zero prior to a call to an errno-setting-function.RequiredCompliant
22.9The value of errno shall be tested against zero after calling an errno-setting-function.RequiredCompliant
22.10The value of errno shall only be tested when the last function to be called was an errno-setting-function.RequiredCompliant

a Rule 22.7, 22.8, 22.9, 22.10 is from MISRA Amendment 1.

Explanatory Notes

These explanatory notes are referenced from the MISRA C:2012 Compliance Summary Tables.

Explanatory Note for Directive 1.1

Information about the implementation-defined behavior for Embedded Coder is available in Configure Run-Time Environment Options . Compiler documentation is out of scope.

Character set encoding is managed by using the SavedCharacterEncoding model parameter. For additional information, see slCharacterEncoding.

Configure the integer division method in the Model Configuration Parameters dialog box, on the Hardware Implementation pane. For additional information, see Configure Run-Time Environment Options

Embedded Coder generates #pragma when the user:

In both instances, you are responsible for documenting the intended use of the #pragma. For more information, see Control Data and Function Placement in Memory by Inserting Pragmas.

To enable the generation of bitfields:

  1. Select at least one of these model configuration parameters:

  2. Create a custom storage class with defined bitfields. See Create Storage Classes by Using the Custom Storage Class Designer for more information.

If your model uses conversion of one datatype to another, Polyspace® Checker might show violation of Dir 1.1.

Explanatory Note for MISRA Directive 3.1

You can link requirements model elements. These links are included in the generated C code to provide traceability from a requirements document, to the model elements, and to the generated code. For additional information, see View Requirements Toolbox Links Associated with Model Elements and View and Link Requirements in Simulink (Requirements Toolbox).

Explanatory Note for Directive 4.1

You can use Polyspace Bug Finder™ to identify run-time errors and Polyspace Code Prover™ to prove the absence of run-time errors. For information, see:

Simulink Design Verifier can be used to detect design errors at the model level. For more information, see Analyze Models for Design Errors (Simulink Design Verifier).

To handle the overflow violations, see Handle Overflows in Simulink Models (Fixed-Point Designer).

Explanatory Note for Directive 4.3

Embedded Coder does not directly call assembly language code. You can add calls to assembly language functions through S-functions, code replacement libraries, Stateflow, and in MATLAB® blocks. These calls are documented as calls to External C Functions. In these cases, you are responsible for encapsulation.

For additional information, see:

Explanatory Note for Directive 4.6

Embedded Coder replaces basic data types with typedefs types, which are compatible with Directive 4.6. A guideline is not required because this behavior is default behavior in Embedded Coder. For additional information, see Replace and Rename Simulink Coder Data Types to Conform to Coding Standards and Typedefs.

Explanatory Note for Directive 4.11

The requirements of this directive are satisfied by:

“Demonstrate statically that the input parameters can never take invalid values”.

You can use Polyspace Code Prover to analyze parameter ranges and prove the absence of run-time errors caused by out-of-range values. For additional information, see Run Polyspace Analysis on Code Generated with Embedded Coder (Polyspace Code Prover).

Explanatory Note for Rule 2.1

Embedded Coder does not check user defined code from the Stateflow. You must take care of the violations reported.

Explanatory Note for Rules 5.1, 5.2, 5.4, 5.5, 5.6, 5.7, and 5.8

Embedded Coder is configurable to limit the number of characters imposed by the implementation. For additional information, see Maximum identifier length.

To ensure unique names for different types of variables (local scope variables, global scope variables, macros, and so on), implement a naming convention. For additional information, see Model Configuration Parameters: Code Generation Symbols.

In case of long identifiers, it is recommended to use shared utilities. For more information, see Generate Shared Utility Code

Explanatory Note for Rule 8.12

Embedded Coder supports the use of enumerated data. The file used to define the enumeration can be either manually or automatically generated. Files defining enumerations generated by Embedded Coder are compliant with MISRA C:2012 Rule 8.12 by design. If you manually create the definition file, you are responsible for ensuring compliance. For additional information, see Use Enumerated Data in Simulink Models.

Explanatory Note for Rule 11.8

If your model uses any storage class with Const or Volatile qualifiers, Polyspace Checker may show violation of Rule 11.8 from the generated code of the model.

Explanatory Note for Rule 13.2

The use of volatile variables may result in a violation of Rule 13.2.

Explanatory Note for Rule 17.3 and 21.2

When the model configuration parameter Leverage target hardware instruction set extensions is set to anything other than None, the generated code may show violation of MISRA C:2012 rules.