Re: [XEN PATCH] automation/eclair: add deviations for MISRA C:2012 Rule 16.3

[Federico Serafini <federico.serafini@xxxxxxxxxxx>]

On 18/12/23 08:42, Jan Beulich wrote:
> On 15.12.2023 10:26, Federico Serafini wrote:
> > --- a/automation/eclair_analysis/ECLAIR/deviations.ecl
> > +++ b/automation/eclair_analysis/ECLAIR/deviations.ecl
> > @@ -327,6 +327,34 @@ therefore have the same behavior of a boolean"
> >   -config=MC3R1.R14.4,etypes+={deliberate, 
> > "stmt(child(cond,child(expr,ref(^<?domain>?::is_dying$))))","src_type(enum)"}
> >   -doc_end
> >   
> > +#
> > +# Series 16.
> > +#
> > +
> > +-doc_begin="Switch clauses ending with continue, goto, return statements are
> > +safe."
> > +-config=MC3R1.R16.3,terminals+={safe, 
> > "node(continue_stmt||goto_stmt||return_stmt)"}
> > +-doc_end
> > +
> > +-doc_begin="Switch clauses ending with a call to a function that does not give
> > +the control back are safe."
> > +-config=MC3R1.R16.3,terminals+={safe, "call(property(noreturn))"}
> > +-doc_end
> > +
> > +-doc_begin="Switch clauses ending with pseudo-keyword \"fallthrough\" are
> > +safe."
> > +-config=MC3R1.R16.3,reports+={safe, 
> > "any_area(end_loc(any_exp(text(/fallthrough;/))))"}
> > +-doc_end
> > +
> > +-doc_begin="Switch clauses ending with failure method \"BUG()\" are safe."
> > +-config=MC3R1.R16.3,reports+={safe, 
> > "any_area(end_loc(any_exp(text(/BUG\\(\\);/))))"}
> > +-doc_end
> > +
> > +-doc_begin="Switch clauses not ending with the break statement are safe if an
> > +explicit comment indicating the fallthrough intention is present."
> > +-config=MC3R1.R16.3,reports+={safe, "any_area(end_loc(any_exp(text(^(?s).*/\\* 
> > [fF]all ?through.? \\*/.*$,0..1))))"}
> > +-doc_end
> > +
> >   #
> >   # Series 20.
> >   #
> > --- a/docs/misra/deviations.rst
> > +++ b/docs/misra/deviations.rst
> > @@ -276,6 +276,34 @@ Deviations related to MISRA C:2012 Rules:
> >          therefore have the same behavior of a boolean.
> >        - Project-wide deviation; tagged as `deliberate` for ECLAIR.
> >   
> > +   * - R16.3
> > +     - Switch clauses ending with continue, goto, return statements are safe.
> > +     - Tagged as `safe` for ECLAIR.
> > +
> > +   * - R16.3
> > +     - Switch clauses ending with a call to a function that does not give
> > +       the control back are safe.
> > +     - Tagged as `safe` for ECLAIR.
> > +
> > +   * - R16.3
> > +     - Switch clauses ending with failure method \"BUG()\" are safe.
> > +     - Tagged as `safe` for ECLAIR.
> > +
> > +   * - R16.3
> > +     - Existing switch clauses not ending with the break statement are safe if
> > +       an explicit comment indicating the fallthrough intention is present.
> > +       However, the use of such comments in new code is deprecated:
> > +       pseudo-keyword "fallthrough" shall be used.
> > +     - Tagged as `safe` for ECLAIR. The accepted comments are:
> > +         - /\* fall through \*/
> > +         - /\* fall through. \*/
> > +         - /\* fallthrough \*/
> > +         - /\* fallthrough. \*/
> > +         - /\* Fall through \*/
> > +         - /\* Fall through. \*/
> > +         - /\* Fallthrough \*/
> > +         - /\* Fallthrough. \*/
> I was puzzled by there being 4 bullet points here, but 5 additions to the
> other file. I don't think the wording here is sufficiently unambiguous towards
> the use of the pseudo-keyword. If that's to remain a single bullet point, imo
> the pseudo-keyword needs mentioning first, and only the talk should be about
> comments as an alternative.
I'll send a v3 to include Stefano's observations and an
explicit bullet point for pseudo-keyword fallthrough.

--
Federico Serafini, M.Sc.

Software Engineer, BUGSENG (http://bugseng.com)