Why MISRA-C:2012 rules 8.1 and 17.3 seem to be disabled even when selected in Polyspace?

I enabled rules MISRA-C:2012 rules 8.1 and 17.3 in my Polyspace project configuration. However, in the Polyspace results, these rules are not activated. For example, when generating a report, these rules are disabled. 

Guideline Description Mode Enabled 
8.1 Types shall be explicitly specified. required FALSE 
17.3 A function shall not be declared implicitly. mandatory FALSE

Answer 1

[MathWorks Support Team]

These two MISRA rules are dedicated to ANSI C90 Standard only.

By default, when you launch Polyspace, the project is using the ANSI C99 Standard compliant, and not C90. As a result, these two rules get disabled during analysis.

In Polyspace R2018a and earlier,

 you can enable them by selecting "Respect C90 Standard" under "Target & Compiler" section of the project configuration.

In command line, the option is: -no-language-extensions

In Polyspace R2018b and newer

, you can enable the C90 standard by switching the "C Standard Version" under the "Target & Compiler" section to C90.

In command line, the option is: -c-version C90

NOTE: This may have some side-effects because the code will be required to be C90 standard compliant.

Below are the documentation references for the rules 8.1 and 17.3:

https://www.mathworks.com/help/bugfinder/ref/misrac2012rule8.1.html

https://www.mathworks.com/help/bugfinder/ref/misrac2012rule17.3.html