[xen staging] automation/eclair: add deviation for Rule 16.4

[patchbot@xxxxxxx]

commit 692f6199bd9a45c93952142c610f0a7dd3b3ef8e
Author:     Federico Serafini <federico.serafini@xxxxxxxxxxx>
AuthorDate: Mon May 6 09:24:50 2024 +0200
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Mon May 6 09:24:50 2024 +0200

    automation/eclair: add deviation for Rule 16.4
    
    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@xxxxxxxxxxx>
    Reviewed-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>
---
 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
--
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