# MISRA-C Deviations

CMSIS-Core (Cortex-M): MISRA-C Deviations

| CMSIS-Core (Cortex-M) Version 5.1.2 CMSIS-Core support for Cortex-M processor-based devices

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MISRA-C Deviations

CMSIS-Core (Cortex-M) uses the common coding rules for CMSIS components that are documented under Introduction.

CMSIS-Core (Cortex-M) violates the following MISRA-C:2004 rules:

- Required Rule 8.5, object/function definition in header file.
  Violated since function definitions in header files are used for function inlining'.
- Advisory Rule 12.4, Side effects on right hand side of logical operator.
  Violated because volatile is used for core register definitions.
- Advisory Rule 14.7, Return statement before end of function.
  Violated to simplify code logic.
- Required Rule 18.4, declaration of union type or object of union type: '{...}'.
  Violated since unions are used for effective representation of core registers.
- Advisory Rule 19.4, Disallowed definition for macro.
  Violated since macros are used for assembler keywords.
- Advisory Rule 19.7, Function-like macro defined.
  Violated since function-like macros are used to generate more efficient code.
- Advisory Rule 19.16, all preprocessing directives must be valid.
  Violated to set default settings for macros.

CMSIS-Core (Cortex-M) violates the following MISRA-C:2012 rules:

- Directive 4.9, function-like macro defined.
  Violated since function-like macros are used to generate more efficient code.
- Rule 1.3, multiple use of '#/##' operators in macro definition.
  Violated since function-like macros are used to generate more efficient code.
- Rule 11.4, conversion between a pointer and integer type.
  Violated because of core register access.
- Rule 11.6, cast from unsigned long to pointer.
  Violated because of core register access.
- Rule 13.5, side effects on right hand side of logical operator.
  Violated because of shift operand is used in macros and functions.
- Rule 14.4, conditional expression should have essentially Boolean type.
  Violated since macros with several instructions are used.
- Rule 15.5, return statement before end of function.
  Violated to simplify code logic.
- Rule 20.10, '#/##' operators used.
  Violated since function-like macros are used to generate more efficient code.
- Rule 21.1, reserved to the compiler.
  Violated since macros with leading underscores are used.

<device>.h files generated by SVDConv.exe violate the following MISRA-C:2004 rules:

- Advisory Rule 20.2, Re-use of C90 identifier pattern.
  Violated since CMSIS macros begin with '__'. Since CMSIS is developed and verified with various compilers this approach is acceptable and avoids conflicts with user symbols.
- Advisory Rule 19.1, Declaration before #include.
  Violated since Interrupt Number Definition Type (IRQn_Type) must be defined before including the core header file.