[XEN PATCH 0/2] misra: deviations of Rule 16.4

[XEN PATCH 0/2] misra: deviations of Rule 16.4

[Federico Serafini]

Define "switch-clause" in terms of the C specification.
Deviate Rule 16.4.

Federico Serafini (2):
  docs/misra: add Terms & Definitions section to rules.rst
  automation/eclair: add deviation for Rule 16.4

 automation/eclair_analysis/ECLAIR/deviations.ecl |  8 ++++++++
 docs/misra/deviations.rst                        | 13 +++++++++++++
 docs/misra/rules.rst                             | 14 ++++++++++++--
 3 files changed, 33 insertions(+), 2 deletions(-)

-- 
2.34.1

[XEN PATCH 1/2] docs/misra: add Terms & Definitions section to rules.rst

[Federico Serafini]

Add a section for terms and definitions used by MISRA but expressed
in terms of the C specification.

Add a definition of "switch clause" to the newly-introduced section.

Link the first use of the term "switch clause" in the document to its
definition.

Suggested-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Federico Serafini <federico.serafini@bugseng.com>
---
Jan you were not completely satisfied by the definition but I didn't find
a better one.
---
 docs/misra/rules.rst | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/docs/misra/rules.rst b/docs/misra/rules.rst
index b7b447e152..d3b70fdf04 100644
--- a/docs/misra/rules.rst
+++ b/docs/misra/rules.rst
@@ -489,8 +489,7 @@ maintainers if you want to suggest a change.
 
    * - `Rule 16.3 <https://gitlab.com/MISRA/MISRA-C/MISRA-C-2012/Example-Suite/-/blob/master/R_16_03.c>`_
      - Required
-     - An unconditional break statement shall terminate every
-       switch-clause
+     - An unconditional break statement shall terminate every switch-clause_
      - In addition to break, also other unconditional flow control statements
        such as continue, return, goto are allowed.
 
@@ -712,3 +711,14 @@ maintainers if you want to suggest a change.
      - The value of a pointer to a FILE shall not be used after the associated
        stream has been closed
      -
+
+Terms & Definitions
+-------------------
+
+.. _switch-clause:
+
+A *switch clause* can be defined as:
+"the non-empty list of statements which follows a non-empty list of
+case/default labels".
+A formal definition is available within the amplification of MISRA C:2012
+Rule 16.1.
-- 
2.34.1

[XEN PATCH 2/2] automation/eclair: add deviation for Rule 16.4

[Federico Serafini]

MISRA C:2012 Rule 16.4 states that "Every switch statement shall have a
default label".
Update ECLAIR configuration to take into account the deviations
agreed during MISRA meetings.

Signed-off-by: Federico Serafini <federico.serafini@bugseng.com>
---
 automation/eclair_analysis/ECLAIR/deviations.ecl |  8 ++++++++
 docs/misra/deviations.rst                        | 13 +++++++++++++
 2 files changed, 21 insertions(+)

diff --git a/automation/eclair_analysis/ECLAIR/deviations.ecl b/automation/eclair_analysis/ECLAIR/deviations.ecl
index d21f112a9b..f09ad71acf 100644
--- a/automation/eclair_analysis/ECLAIR/deviations.ecl
+++ b/automation/eclair_analysis/ECLAIR/deviations.ecl
@@ -384,6 +384,14 @@ 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
 
+-doc_begin="Switch statements having a controlling expression of enum type deliberately do not have a default case: gcc -Wall enables -Wswitch which warns (and breaks the build as we use -Werror) if one of the enum labels is missing from the switch."
+-config=MC3R1.R16.4,reports+={deliberate,'any_area(kind(context)&&^.* has no `default.*$&&stmt(node(switch_stmt)&&child(cond,skip(__non_syntactic_paren_stmts,type(canonical(enum_underlying_type(any())))))))'}
+-doc_end
+
+-doc_begin="A switch statement with a single switch clause and no default label may be used in place of an equivalent if statement if it is considered to improve readability."
+-config=MC3R1.R16.4,switch_clauses+={deliberate,"switch(1)&&default(0)"}
+-doc_end
+
 -doc_begin="A switch statement with a single switch clause and no default label may be used in place of an equivalent if statement if it is considered to improve readability."
 -config=MC3R1.R16.6,switch_clauses+={deliberate, "default(0)"}
 -doc_end
diff --git a/docs/misra/deviations.rst b/docs/misra/deviations.rst
index ed0c1e8ed0..39cc321a27 100644
--- a/docs/misra/deviations.rst
+++ b/docs/misra/deviations.rst
@@ -334,6 +334,19 @@ Deviations related to MISRA C:2012 Rules:
          - /\* Fallthrough \*/
          - /\* Fallthrough. \*/
 
+   * - R16.4
+     - Switch statements having a controlling expression of enum type
+       deliberately do not have a default case: gcc -Wall enables -Wswitch
+       which warns (and breaks the build as we use -Werror) if one of the enum
+       labels is missing from the switch.
+     - Tagged as `deliberate` for ECLAIR.
+
+   * - R16.4
+     - A switch statement with a single switch clause and no default label may
+       be used in place of an equivalent if statement if it is considered to
+       improve readability.
+     - Tagged as `deliberate` for ECLAIR.
+
    * - R16.6
      - A switch statement with a single switch clause and no default label may
        be used in place of an equivalent if statement if it is considered to
-- 
2.34.1

Re: [XEN PATCH 1/2] docs/misra: add Terms & Definitions section to rules.rst

[Stefano Stabellini]

On Fri, 3 May 2024, Federico Serafini wrote:
> Add a section for terms and definitions used by MISRA but expressed
> in terms of the C specification.
> 
> Add a definition of "switch clause" to the newly-introduced section.
> 
> Link the first use of the term "switch clause" in the document to its
> definition.
> 
> Suggested-by: Jan Beulich <jbeulich@suse.com>
> Signed-off-by: Federico Serafini <federico.serafini@bugseng.com>

Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>


> ---
> Jan you were not completely satisfied by the definition but I didn't find
> a better one.
> ---
>  docs/misra/rules.rst | 14 ++++++++++++--
>  1 file changed, 12 insertions(+), 2 deletions(-)
> 
> diff --git a/docs/misra/rules.rst b/docs/misra/rules.rst
> index b7b447e152..d3b70fdf04 100644
> --- a/docs/misra/rules.rst
> +++ b/docs/misra/rules.rst
> @@ -489,8 +489,7 @@ maintainers if you want to suggest a change.
>  
>     * - `Rule 16.3 <https://gitlab.com/MISRA/MISRA-C/MISRA-C-2012/Example-Suite/-/blob/master/R_16_03.c>`_
>       - Required
> -     - An unconditional break statement shall terminate every
> -       switch-clause
> +     - An unconditional break statement shall terminate every switch-clause_
>       - In addition to break, also other unconditional flow control statements
>         such as continue, return, goto are allowed.
>  
> @@ -712,3 +711,14 @@ maintainers if you want to suggest a change.
>       - The value of a pointer to a FILE shall not be used after the associated
>         stream has been closed
>       -
> +
> +Terms & Definitions
> +-------------------
> +
> +.. _switch-clause:
> +
> +A *switch clause* can be defined as:
> +"the non-empty list of statements which follows a non-empty list of
> +case/default labels".
> +A formal definition is available within the amplification of MISRA C:2012
> +Rule 16.1.
> -- 
> 2.34.1
> 

Re: [XEN PATCH 2/2] automation/eclair: add deviation for Rule 16.4

[Stefano Stabellini]

On Fri, 3 May 2024, Federico Serafini wrote:
> MISRA C:2012 Rule 16.4 states that "Every switch statement shall have a
> default label".
> Update ECLAIR configuration to take into account the deviations
> agreed during MISRA meetings.
> 
> Signed-off-by: Federico Serafini <federico.serafini@bugseng.com>

Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>


> ---
>  automation/eclair_analysis/ECLAIR/deviations.ecl |  8 ++++++++
>  docs/misra/deviations.rst                        | 13 +++++++++++++
>  2 files changed, 21 insertions(+)
> 
> diff --git a/automation/eclair_analysis/ECLAIR/deviations.ecl b/automation/eclair_analysis/ECLAIR/deviations.ecl
> index d21f112a9b..f09ad71acf 100644
> --- a/automation/eclair_analysis/ECLAIR/deviations.ecl
> +++ b/automation/eclair_analysis/ECLAIR/deviations.ecl
> @@ -384,6 +384,14 @@ 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.? \\*/.*$,0..1))))"}
>  -doc_end
>  
> +-doc_begin="Switch statements having a controlling expression of enum type deliberately do not have a default case: gcc -Wall enables -Wswitch which warns (and breaks the build as we use -Werror) if one of the enum labels is missing from the switch."
> +-config=MC3R1.R16.4,reports+={deliberate,'any_area(kind(context)&&^.* has no `default.*$&&stmt(node(switch_stmt)&&child(cond,skip(__non_syntactic_paren_stmts,type(canonical(enum_underlying_type(any())))))))'}
> +-doc_end
> +
> +-doc_begin="A switch statement with a single switch clause and no default label may be used in place of an equivalent if statement if it is considered to improve readability."
> +-config=MC3R1.R16.4,switch_clauses+={deliberate,"switch(1)&&default(0)"}
> +-doc_end
> +
>  -doc_begin="A switch statement with a single switch clause and no default label may be used in place of an equivalent if statement if it is considered to improve readability."
>  -config=MC3R1.R16.6,switch_clauses+={deliberate, "default(0)"}
>  -doc_end
> diff --git a/docs/misra/deviations.rst b/docs/misra/deviations.rst
> index ed0c1e8ed0..39cc321a27 100644
> --- a/docs/misra/deviations.rst
> +++ b/docs/misra/deviations.rst
> @@ -334,6 +334,19 @@ Deviations related to MISRA C:2012 Rules:
>           - /\* Fallthrough \*/
>           - /\* Fallthrough. \*/
>  
> +   * - R16.4
> +     - Switch statements having a controlling expression of enum type
> +       deliberately do not have a default case: gcc -Wall enables -Wswitch
> +       which warns (and breaks the build as we use -Werror) if one of the enum
> +       labels is missing from the switch.
> +     - Tagged as `deliberate` for ECLAIR.
> +
> +   * - R16.4
> +     - A switch statement with a single switch clause and no default label may
> +       be used in place of an equivalent if statement if it is considered to
> +       improve readability.
> +     - Tagged as `deliberate` for ECLAIR.
> +
>     * - R16.6
>       - A switch statement with a single switch clause and no default label may
>         be used in place of an equivalent if statement if it is considered to
> -- 
> 2.34.1
>