From 53dd9f3e92c12abe3e5ae9207d608bb7afb6dca8 Mon Sep 17 00:00:00 2001 From: Nicola Vetrini Date: Mon, 14 Jul 2025 16:14:57 +0200 Subject: [PATCH] misra: add deviation of Rule 10.1 for unary minus 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 Signed-off-by: Federico Serafini Signed-off-by: Victor Lira Reviewed-by: Stefano Stabellini Signed-off-by: Dmytro Prokopchuk --- 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