The following section contains a list of all MISRA-C-2004 rules. Column UCS Decision shows which rules are Accepted or Ignored by the UNICENS development team.

Environment

Rule #	Description	Class	UCS Decision	Verified by	Comments
1.1	All code shall conform to ISO 9899:1990 "Programming languages - C", amended and corrected by ISO/IEC 9899/COR1:1995, ISO/IEC 9899/AMD1:1995, and ISO/IEC 9899/COR2:1996.	Required	Accepted	Parasoft C++-test, GNU C Compiler, Microsoft C/C++ Compiler
1.2	No reliance shall be placed on undefined or unspecified behaviour.	Required	Accepted	Code Review
1.3	Multiple compilers and/or languages shall only be used if there is a common defined interface standard for object code to which the languages/compilers/assemblers conform.	Required	Accepted	N/A	Compiler specific implementations are not allowed by UNICENS coding style guide.
1.4	The compiler/linker shall be checked to ensure that 31 character significance and case sensitivity are supported for external identifiers.	Required	N/A	N/A	UNICENS is delivered as source code and is compiled by customers.
1.5	Floating-point implementations should comply with a defined floating-point standard.	Advisory	Accepted	N/A	No floating point data tyes are allowed by UNICENS Coding Style.

Language Extensions

Rule #	Description	Class	UCS Decision	Verified by	Comments
2.1	Assembly language shall be encapsulated and isolated.	Required	Accepted	Parasoft C++-test
2.2	Source code shall only use /* ... */ style comments.	Required	Accepted	Parasoft C++-test
2.3	The character sequence /* shall not be used within a comment.	Required	Accepted	Parasoft C++-test
2.4	Sections of code should not be "commented out".	Advisory	Ignored	Parasoft C++-test	In some cases comments contain source code sequences to explain a particular implementation.

Documentation

Rule #	Description	Class	UCS Decision	Verified by	Comments
3.1	All usage of implementation-defined behaviour shall be documented.	Required	Accepted	Code Review
3.2	The character set and the corresponding encoding shall be documented.	Required	Accepted	Code Review
3.3	The implementation of integer division in the chosen compiler should be determined, documented and taken into account.	Advisory	N/A	N/A	UNICENS is delivered as source code and is compiled by customers.
3.4	All uses of the #pragma directive shall be documented and explained.	Required	Accepted	Parasoft C++-test
3.5	The implementation-defined behaviour and packing of bitfields shall be documented if it is being relied upon.	Required	Accepted	Code Review
3.6	All libraries used in production code shall be written to comply with the provisions of this document, and shall have been subject to appropriate validation.	Required	Accepted	Code Review

Charater Sets

Rule #	Description	Class	UCS Decision	Verified by	Comments
4.1	Only those escape sequences that are defined in the ISO C standard shall be used.	Required	Accepted	Parasoft C++-test
4.2	Trigraphs shall not be used.	Required	Accepted	Parasoft C++-test

Identifiers

Rule #	Description	Class	UCS Decision	Verified by	Comments
5.1	Identifiers (internal and external) shall not rely on the significance of more than 31 characters.	Required	Accepted	Parasoft C++-test
5.2	Identifiers in an inner scope shall not use the same name as an identifier in an outer scope, and therefore hide that identifier.	Required	Accepted	Parasoft C++-test
5.3	A typedef name shall be a unique identifier.	Required	Accepted	Parasoft C++-test
5.4	A tag name shall be a unique identifier.	Required	Accepted	Parasoft C++-test
5.5	No object or function identifier with static storage duration should be reused.	Advisory	Accepted	Parasoft C++-test
5.6	No identifier in one name space should have the same spelling as an identifier in another name space, with the exception of structure and union member names.	Advisory	Ignored	Parasoft C++-test	Reuse of variable names within several namespaces can not be avoided. The rule is not practicable.
5.7	No identifier name should be reused.	Advisory	Ignored	Parasoft C++-test	Reuse of variable names can not be avoided. The rule is not practicable.

Types

Rule #	Description	Class	UCS Decision	Verified by
6.1	The plain char type shall be used only for the storage and use of character values.	Required	Accepted	Parasoft C++-test
6.2	Signed and unsigned char type shall be used only for the storage and use of numeric values.	Required	Accepted	Parasoft C++-test
6.3	Typedefs that indicate size and signedness should be used in place of the basic types.	Advisory	Accepted	Parasoft C++-test
6.4	Bit fields shall only be defined to be of type unsigned int or signed int.	Required	Accepted	Parasoft C++-test
6.5	Bit fields of type signed int shall be at least 2 bits long.	Required	Accepted	Parasoft C++-test

Octal Constants

Rule #	Description	Class	UCS Decision	Verified by	Comments
7.1	Octal constants (other than zero) and octal escape sequences shall not be used.	Required	Accepted	Parasoft C++-test

Declarations and Definitions

Rule #	Description	Class	UCS Decision	Verified by
8.1	Functions shall have prototype declarations and the prototype shall be visible at both the function definition and call.	Required	Accepted	Parasoft C++-test
8.2	Whenever an object or function is declared or defined, its type shall be explicitly stated.	Required	Accepted	Parasoft C++-test
8.3	For each function parameter the type given in the declaration and definition shall be identical, and the return types shall also be identical.	Required	Accepted	Parasoft C++-test
8.4	If objects or functions are declared more than once their types shall be compatible.	Required	Accepted	Parasoft C++-test
8.5	There shall be no definitions of objects or functions in a header file.	Required	Accepted	Parasoft C++-test
8.6	Functions shall be declared at file scope.	Required	Accepted	Parasoft C++-test
8.7	Objects shall be defined at block scope if they are only accessed within a single function.	Required	Accepted	Parasoft C++-test
8.8	An external object or function shall be declared in one and only one file.	Required	Accepted	Parasoft C++-test
8.9	An identifier with external linkage shall have exactly one external definition.	Required	Accepted	Parasoft C++-test
8.10	All declarations and definitions of objects or functions at file scope shall have internal linkage unless external linkage is required.	Required	Accepted	Parasoft C++-test
8.11	The static storage class specifier shall be used in definitions and declarations of objects and functions that have internal linkage.	Required	Accepted	Parasoft C++-test
8.12	When an array is declared with external linkage, its size shall be stated explicitly or defined implicitly by initialisation.	Required	Accepted	Parasoft C++-test

Initialisation

Rule #	Description	Class	UCS Decision	Verified by
9.1	All automatic variables shall have been assigned a value before being used.	Required	Accepted	Parasoft C++-test
9.2	Braces shall be used to indicate and match the structure in the non-zero initialisation of arrays and structures.	Required	Accepted	Parasoft C++-test
9.3	In an enumerator list, the "=" construct shall not be used to explicitly initialise members other than the first, unless all items are explicitly initialised.	Required	Accepted	Parasoft C++-test

Arithmetic Type Conversions

Rule #	Description	Class	UCS Decision	Verified by
10.1	The value of an expression of integer type shall not be implicitly converted to a different underlying type if: a) it is not a version to a wider integer type of the same signedness, or b) the expression is complex, or c) the expression is not constant and is a function argument, or d) the expression is not constant and is a return expression.	Required	Accepted	Parasoft C++-test
10.2	The value of an expression of floating type shall not be implicitly converted to a different type if: a) it is not a version to a wider floating type, or b) the expression is complex, or c) the expression is a function argument, or d) the expression is a return expression.	Required	Accepted	Parasoft C++-test
10.3	The value of a complex expression of integer type may only be cast to a type that is narrower and of the same signedness as the underlying type of the expression.	Required	Accepted	Parasoft C++-test
10.4	The value of a complex expression of floating type may only be cast to a narrower floating type.	Required	Accepted	Parasoft C++-test
10.5	If the bitwise operators ~ and << are applied to an operand of underlying type unsigned char or unsigned short, the result shall be immediately cast to the underlying type of the operand.	Required	Accepted	Parasoft C++-test
10.6	A "U" suffix shall be applied to all constants of unsigned type.	Required	Accepted	Parasoft C++-test

Pointer Type Conversions

Rule #	Description	Class	UCS Decision	Verified by
11.1	Conversions shall not be performed between a pointer to a function and any type other than an integral type.	Required	Accepted	Parasoft C++-test
11.2	Conversions shall not be performed between a pointer to object and any type other than an integral type, another pointer to object or a pointer to void.	Required	Accepted	Parasoft C++-test
11.3	A cast should not be performed between a pointer type and an integral type.	Required	Accepted	Parasoft C++-test
11.4	A cast should not be performed between a pointer to object type and a different pointer to object type.	Required	Accepted	Parasoft C++-test
11.5	A cast shall not be performed that removes any const or volatile qualification from the type addressed by a pointer.	Required	Accepted	Parasoft C++-test

Expressions

Rule #	Description	Class	UCS Decision	Verified by
12.1	Limited dependence should be placed on C's operator precedence rules in expressions.	Required	Accepted	Parasoft C++-test
12.2	The value of an expression shall be the same under any order of evaluation that the standard permits.	Required	Accepted	Parasoft C++-test
12.3	The sizeof operator shall not be used on expressions that contain side effects.	Required	Accepted	Parasoft C++-test
12.4	The right-hand operand of a logical && or \|\| operator shall not contain side effects.	Required	Accepted	Parasoft C++-test
12.5	The operands of a logical && or \|\| shall be primary-expressions.	Required	Accepted	Parasoft C++-test
12.6	The operands of logical operators (&&, \|\| and !) should be effectively Boolean. Expressions that are effectively Boolean should not be used as operands to operators other than (&&, \|\| and !).	Advisory	Accepted	Parasoft C++-test
12.7	Bitwise operators shall not be applied to operands whose underlying type is signed.	Required	Accepted	Parasoft C++-test
12.8	The right-hand operand of a shift operator shall lie between zero and one less than the width in bits of the underlying type of the left-hand operand.	Required	Accepted	Parasoft C++-test
12.9	The unary minus operator shall not be applied to an expression whose underlying type is unsigned.	Required	Accepted	Parasoft C++-test
12.10	The comma operator shall not be used.	Required	Accepted	Parasoft C++-test
12.11	Evaluation of constant unsigned integer expressions should not lead to wrap-around.	Advisory	Accepted	Parasoft C++-test
12.12	The underlying bit representations of floating-point values shall not be used.	Required	Accepted	Parasoft C++-test
12.13	The increment (++) and decrement (–) operators should not be mixed with other operators in an expression.	Advisory	Accepted	Parasoft C++-test

Control Statement Expressions

Rule #	Description	Class	UCS Decision	Verified by
13.1	Assignment operators shall not be used in expressions that yield a Boolean value.	Required	Accepted	Parasoft C++-test
13.2	Tests of a value against zero should be made explicit, unless the operand is effectively Boolean.	Advisory	Accepted	Parasoft C++-test
13.3	Floating-point expressions shall not be tested for equality or inequality.	Required	Accepted	Parasoft C++-test
13.4	The controlling expression of a for statement shall not contain any objects of floating type.	Required	Accepted	Parasoft C++-test
13.5	The three expressions of a for statement shall be concerned only with loop control.	Required	Accepted	Parasoft C++-test
13.6	Numeric variables being used within a for loop for iteration counting shall not be modified in the body of the loop.	Required	Accepted	Parasoft C++-test
13.7	Boolean operations whose results are invariant shall not be permitted.	Required	Accepted	Parasoft C++-test

Control Flow

Rule #	Description	Class	UCS Decision	Verified by	Comments
14.1	There shall be no unreachable code.	Required	Accepted	Parasoft C++-test
14.2	All non-null statements shall either: a) have at least one side effect however executed, or b) cause control flow to change	Required	Accepted	Parasoft C++-test
14.3	Before preprocessing, a null statement shall only occur on a line by itself; it may be followed by a comment provided that the first character following the null statement is a white-space character.	Required	Accepted	Parasoft C++-test
14.4	The goto statement shall not be used.	Required	Accepted	Parasoft C++-test
14.5	The continue statement shall not be used.	Required	Accepted	Parasoft C++-test
14.6	For any iteration statement there shall be at most one break statement used for loop termination.	Required	Accepted	Parasoft C++-test
14.7	A function shall have a single point of exit at the end of the function.	Required	Accepted	Parasoft C++-test
14.8	The statement forming the body of a switch, while, do ... while or for statement shall be a compound statement.	Required	Accepted	Parasoft C++-test
14.9	An if (expression) construct shall be followed by a compound statement. The else keyword shall be followed by either a compound statement, or another if statement.	Required	Accepted	Parasoft C++-test
14.10	All if ... else if constructs shall be terminated with an else clause.	Required	Ignored	Parasoft C++-test	Avoid empty else branches.

Switch Statements

Rule #	Description	Class	UCS Decision	Verified by
15.1	A switch label shall only be used when the most closely-enclosing compound statement is the body of a switch statement.	Required	Accepted	Parasoft C++-test
15.2	An unconditional break statement shall terminate every non-empty switch clause.	Required	Accepted	Parasoft C++-test
15.3	The final clause of a switch statement shall be the default clause.	Required	Accepted	Parasoft C++-test
15.4	A switch expression shall not represent a value that is effectively Boolean.	Required	Accepted	Parasoft C++-test
15.5	Every switch statement shall have at least one case clause.	Required	Accepted	Parasoft C++-test

Functions

Rule #	Description	Class	UCS Decision	Verified by
16.1	Functions shall not be defined with a variable number of arguments.	Required	Accepted	Parasoft C++-test
16.2	Functions shall not call themselves, either directly or indirectly.	Required	Accepted	Parasoft C++-test
16.3	Identifiers shall be given for all of the parameters in a function prototype declaration.	Required	Accepted	Parasoft C++-test
16.4	The identifiers used in the declaration and definition of a function shall be identical.	Required	Accepted	Parasoft C++-test
16.5	Functions with no parameters shall be declared with parameter type void.	Required	Accepted	Parasoft C++-test
16.6	The number of arguments passed to a function shall match the number of parameters.	Required	Accepted	Parasoft C++-test
16.7	A pointer parameter in a function prototype should be declared as pointer to const if the pointer is not used to modify the addressed object.	Advisory	Accepted	Parasoft C++-test
16.8	All exit paths from a function with non-void return type shall have an explicit return statement with an expression.	Required	Accepted	Parasoft C++-test
16.9	A function identifier shall only be used with either a preceding &, or with a parenthesised parameter list, which may be empty.	Required	Accepted	Parasoft C++-test
16.10	If a function returns error information, then that error information shall be tested.	Required	Accepted	Parasoft C++-test

Pointers and Arrays

Rule #	Description	Class	UCS Decision	Verified by
17.1	Pointer arithmetic shall only be applied to pointers that address an array or array element.	Required	Accepted	Parasoft C++-test
17.2	Pointer subtraction shall only be applied to pointers that address elements of the same array.	Required	Accepted	Parasoft C++-test
17.3	>, >=, <, <= shall not be applied to pointer types except where they point to the same array.	Required	Accepted	Parasoft C++-test
17.4	Array indexing shall be the only allowed form of pointer arithmetic.	Required	Accepted	Parasoft C++-test
17.5	The declaration of objects should contain no more than 2 levels of pointer indirection.	Advisory	Accepted	Parasoft C++-test
17.6	The address of an object with automatic storage shall not be assigned to another object that may persist after the first object has ceased to exist.	Required	Accepted	Parasoft C++-test

Structures and Unions

Rule #	Description	Class	UCS Decision	Verified by
18.1	All structure and union types shall be complete at the end of a translation unit.	Required	Accepted	Parasoft C++-test
18.2	An object shall not be assigned to an overlapping object.	Required	Accepted	Parasoft C++-test
18.3	An area of memory shall not be reused for unrelated purposes.	Required	Accepted	Parasoft C++-test
18.4	Unions shall not be used.	Required	Accepted	Parasoft C++-test

Preprocessing Directives

Rule #	Description	Class	UCS Decision	Verified by
19.1	#include statements in a file should only be preceded by other preprocessor directives or comments.	Advisory	Accepted	Parasoft C++-test
19.2	Non-standard characters should not occur in header file names in #include directives.	Advisory	Accepted	Parasoft C++-test
19.3	The #include directive shall be followed by either a <filename> or "filename" sequence.	Required	Accepted	Parasoft C++-test
19.4	C macros shall only expand to a braced initialiser, a constant, a parenthesised expression, a type qualifier, a storage class specifier, or a do-while-zero construct.	Required	Accepted	Parasoft C++-test
19.5	Macros shall not be #define'd or #undef'd within a block.	Required	Accepted	Parasoft C++-test
19.6	#undef shall not be used.	Required	Accepted	Parasoft C++-test
19.7	A function should be used in preference to a function-like macro.	Advisory	Accepted	Parasoft C++-test
19.8	A function-like macro shall not be invoked without all of its arguments.	Required	Accepted	Parasoft C++-test
19.9	Arguments to a function-like macro shall not contain tokens that look like preprocessing directives.	Required	Accepted	Parasoft C++-test
19.10	In the definition of a function-like macro each instance of a parameter shall be enclosed in parentheses unless it is used as the operand of # or ##.	Required	Accepted	Parasoft C++-test
19.11	All macro identifiers in preprocessor directives shall be defined before use, except in #ifdef and #ifndef preprocessor directives and the defined() operator.	Required	Accepted	Parasoft C++-test
19.12	There shall be at most one occurrence of the # or ## preprocessor operators in a single macro definition.	Required	Accepted	Parasoft C++-test
19.13	The # and ## preprocessor operators should not be used.	Advisory	Accepted	Parasoft C++-test
19.14	The defined preprocessor operator shall only be used in one of the two standard forms.	Required	Accepted	Parasoft C++-test
19.15	Precautions shall be taken in order to prevent the contents of a header file being included twice.	Required	Accepted	Parasoft C++-test
19.16	Preprocessing directives shall be syntactically meaningful even when excluded by the preprocessor.	Required	Accepted	Parasoft C++-test
19.17	All #else, #elif and #endif preprocessor directives shall reside in the same file as the #if or #ifdef directive to which they are related.	Required	Accepted	Parasoft C++-test

Standard Libraries

Rule #	Description	Class	UCS Decision	Verified by
20.1	Reserved identifiers, macros and functions in the standard library, shall not be defined, redefined or undefined.	Required	Accepted	Parasoft C++-test
20.2	The names of standard library macros, objects and functions shall not be reused.	Required	Accepted	Parasoft C++-test
20.3	The validity of values passed to library functions shall be checked.	Required	Accepted	Parasoft C++-test
20.4	Dynamic heap memory allocation shall not be used.	Required	Accepted	Parasoft C++-test
20.5	The error indicator errno shall not be used.	Required	Accepted	Parasoft C++-test
20.6	The macro offsetof, in library <stddef.h>, shall not be used.	Required	Accepted	Parasoft C++-test
20.7	The setjmp macro and the longjmp function shall not be used.	Required	Accepted	Parasoft C++-test
20.8	The signal handling facilities of <signal.h> shall not be used.	Required	Accepted	Parasoft C++-test
20.9	The input/output library <stdio.h> shall not be used in production code.	Required	Accepted	Parasoft C++-test
20.10	The library functions atof, atoi and atol from library <stdlib.h> shall not be used.	Required	Accepted	Parasoft C++-test
20.11	The library functions abort, exit, getenv and system from library <stdlib.h> shall not be used.	Required	Accepted	Parasoft C++-test
20.12	The time handling functions of library <time.h> shall not be used.	Required	Accepted	Parasoft C++-test

Run-time Failures

Rule #	Description	Class	UCS Decision	Verified by	Comments
21.1	Minimisation of run-time failures shall be ensured by the use of at least one of: a) static analysis tools/techniques b) dynamic analysis tools/techniques c) explicit coding of checks to handle run-time failures.	Required	Accepted	Static Analysis & Unit Testing: Parasoft C++-test