From: Nicola Vetrini <nicola.vetr...@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 quantity has
a semantics (wrap around) that is well-known to all Xen developers.
Thus, this operation is deemed safe.
No functional change.
Signed-off-by: Nicola Vetrini <nicola.vetr...@bugseng.com>
Signed-off-by: Federico Serafini <federico.seraf...@bugseng.com>
Signed-off-by: Victor Lira <victorm.l...@amd.com>
---
Changes v1:
- add rule title to commit message
---
Cc: Andrew Cooper <andrew.coop...@citrix.com>
Cc: Anthony PERARD <anthony.per...@vates.tech>
Cc: Michal Orzel <michal.or...@amd.com>
Cc: Jan Beulich <jbeul...@suse.com>
Cc: Julien Grall <jul...@xen.org>
Cc: Roger Pau Monné <roger....@citrix.com>
Cc: Stefano Stabellini <sstabell...@kernel.org>
Cc: Nicola Vetrini <nicola.vetr...@bugseng.com>
Cc: Federico Serafini <federico.seraf...@bugseng.com>
Cc: Bertrand Marquis <bertrand.marq...@arm.com>
---
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 303b06203a..2cfce850bd 100644
--- a/automation/eclair_analysis/ECLAIR/deviations.ecl
+++ b/automation/eclair_analysis/ECLAIR/deviations.ecl
@@ -347,6 +347,12 @@ constant expressions are required.\""
"any()"}
-doc_end
+-doc_begin="Unary minus operations on non-negative integers have a semantics
(wrap around) that is well-known to all Xen developers."
+-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 cfdd1a9838..c5897e31c5 100644
--- a/docs/misra/deviations.rst
+++ b/docs/misra/deviations.rst
@@ -321,6 +321,12 @@ 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 an unsigned quantity has a
+ semantics (wrap around) that is well-known to all Xen developers.
+ 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
--
2.47.0
