From: Nicola Vetrini <nicola.vetrini@bugseng.com>
MISRA C Rule 10.1 states:
"Operands shall not be of an inappropriate essential type"
The unary minus operator applied to an unsigned type(s) has
a semantics (wrap around) that is well-defined by the toolchains.
Thus, this operation is deemed safe.
No functional change.
Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
Signed-off-by: Federico Serafini <federico.serafini@bugseng.com>
Signed-off-by: Victor Lira <victorm.lira@amd.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Signed-off-by: Dmytro Prokopchuk <dmytro_prokopchuk1@epam.com>
---
Changes v2:
- improve the wording
---
automation/eclair_analysis/ECLAIR/deviations.ecl | 6 ++++++
docs/misra/deviations.rst | 6 ++++++
2 files changed, 12 insertions(+)
diff --git a/automation/eclair_analysis/ECLAIR/deviations.ecl b/automation/eclair_analysis/ECLAIR/deviations.ecl
index e8f513fbc5..8504e850c1 100644
--- a/automation/eclair_analysis/ECLAIR/deviations.ecl
+++ b/automation/eclair_analysis/ECLAIR/deviations.ecl
@@ -342,6 +342,12 @@ constant expressions are required.\""
"any()"}
-doc_end
+-doc_begin="Unary minus operations on unsigned type(s) have a semantics (wrap around) that is well-defined by the toolchains."
+-config=MC3A2.R10.1,etypes+={safe,
+ "stmt(node(unary_operator)&&operator(minus))",
+ "src_expr(definitely_in(0..))"}
+-doc_end
+
#
# Series 11
#
diff --git a/docs/misra/deviations.rst b/docs/misra/deviations.rst
index 0d56d45b66..620e97f0bd 100644
--- a/docs/misra/deviations.rst
+++ b/docs/misra/deviations.rst
@@ -325,6 +325,12 @@ Deviations related to MISRA C:2012 Rules:
If no bits are set, 0 is returned.
- Tagged as `safe` for ECLAIR.
+ * - R10.1
+ - Applying the unary minus operator to unsigned type(s) has a
+ semantics (wrap around) that is well-defined by the toolchains.
+ For this reason, the operation is safe.
+ - Tagged as `safe` for ECLAIR.
+
* - R11.1
- The conversion from a function pointer to unsigned long or (void \*) does
not lose any information, provided that the target type has enough bits
--
2.43.0