[XEN,v2,for-4.20,4/7] automation/eclair_analysis: address violations of MISRA C Rule 20.7

Commit Message

Nicola Vetrini June 26, 2024, 1:28 p.m. UTC

MISRA C Rule 20.7 states: "Expressions resulting from the expansion
of macro parameters shall be enclosed in parentheses".

The local helpers GRP2 and XADD in the x86 emulator use their first
argument as the constant expression for a case label. This pattern
is deviated project-wide, because it is very unlikely to induce
developer confusion and result in the wrong control flow being
carried out.

No functional change.

Signed-off-by: Nicola Vetrini <[e-mail]>
Reviewed-by: Stefano Stabellini <[e-mail]>
---
Changes in v2:
- Introduce a deviation instead of adding parentheses
---
 automation/eclair_analysis/ECLAIR/deviations.ecl | 6 ++++--
 docs/misra/deviations.rst                        | 3 ++-
 2 files changed, 6 insertions(+), 3 deletions(-)

Patch

diff --git a/automation/eclair_analysis/ECLAIR/deviations.ecl b/automation/eclair_analysis/ECLAIR/deviations.ecl
index dcff4f40136c..d12be858fe84 100644
--- a/automation/eclair_analysis/ECLAIR/deviations.ecl
+++ b/automation/eclair_analysis/ECLAIR/deviations.ecl
@@ -458,13 +458,15 @@  unexpected result when the structure is given as argument to a sizeof() operator
 
 -doc_begin="Code violating Rule 20.7 is safe when macro parameters are used: (1)
 as function arguments; (2) as macro arguments; (3) as array indices; (4) as lhs
-in assignments; (5) as initializers, possibly designated, in initalizer lists."
+in assignments; (5) as initializers, possibly designated, in initalizer lists;
+(6) as the constant expression in a switch clause label."
 -config=MC3R1.R20.7,expansion_context=
 {safe, "context(__call_expr_arg_contexts)"},
 {safe, "left_right(^[(,\\[]$,^[),\\]]$)"},
 {safe, "context(skip_to(__expr_non_syntactic_contexts, stmt_child(node(array_subscript_expr), subscript)))"},
 {safe, "context(skip_to(__expr_non_syntactic_contexts, stmt_child(operator(assign), lhs)))"},
-{safe, "context(skip_to(__expr_non_syntactic_contexts, stmt_child(node(init_list_expr||designated_init_expr), init)))"}
+{safe, "context(skip_to(__expr_non_syntactic_contexts, stmt_child(node(init_list_expr||designated_init_expr), init)))"},
+{safe, "context(skip_to(__expr_non_syntactic_contexts, stmt_child(node(case_stmt), lower||upper)))"}
 -doc_end
 
 -doc_begin="Violations involving the __config_enabled macros cannot be fixed without
diff --git a/docs/misra/deviations.rst b/docs/misra/deviations.rst
index c6a2affc6a0b..7be232212339 100644
--- a/docs/misra/deviations.rst
+++ b/docs/misra/deviations.rst
@@ -416,7 +416,8 @@  Deviations related to MISRA C:2012 Rules:
        (2) as macro arguments;
        (3) as array indices;
        (4) as lhs in assignments;
-       (5) as initializers, possibly designated, in initalizer lists.
+       (5) as initializers, possibly designated, in initalizer lists;
+       (6) as constant expressions of switch case labels.
      - Tagged as `safe` for ECLAIR.
 
    * - R20.7