Update ECLAIR configuration to deviate some cases where not using
the return value of a function is not dangerous.

Signed-off-by: Federico Serafini <federico.serafini@bugseng.com>
---
Changes in v2:
- do not deviate strlcpy and strlcat.
---
 automation/eclair_analysis/ECLAIR/deviations.ecl | 4 ++++
 docs/misra/deviations.rst                        | 9 +++++++++
 2 files changed, 13 insertions(+)

diff --git a/automation/eclair_analysis/ECLAIR/deviations.ecl b/automation/eclair_analysis/ECLAIR/deviations.ecl
index 447c1e6661..97281082a8 100644
--- a/automation/eclair_analysis/ECLAIR/deviations.ecl
+++ b/automation/eclair_analysis/ECLAIR/deviations.ecl
@@ -413,6 +413,10 @@ explicit comment indicating the fallthrough intention is present."
 -config=MC3R1.R17.1,macros+={hide , "^va_(arg|start|copy|end)$"}
 -doc_end
 
+-doc_begin="Not using the return value of a function do not endanger safety if it coincides with the first actual argument."
+-config=MC3R1.R17.7,calls+={safe, "any()", "decl(name(__builtin_memcpy||__builtin_memmove||__builtin_memset||cpumask_check))"}
+-doc_end
+
 #
 # Series 18.
 #
diff --git a/docs/misra/deviations.rst b/docs/misra/deviations.rst
index 36959aa44a..2a10de5a66 100644
--- a/docs/misra/deviations.rst
+++ b/docs/misra/deviations.rst
@@ -364,6 +364,15 @@ Deviations related to MISRA C:2012 Rules:
        by `stdarg.h`.
      - Tagged as `deliberate` for ECLAIR.
 
+   * - R17.7
+     - Not using the return value of a function do not endanger safety if it
+       coincides with the first actual argument.
+     - Tagged as `safe` for ECLAIR. Such functions are:
+         - __builtin_memcpy()
+         - __builtin_memmove()
+         - __builtin_memset()
+         - __cpumask_check()
+
    * - R20.4
      - The override of the keyword \"inline\" in xen/compiler.h is present so
        that section contents checks pass when the compiler chooses not to
-- 
2.34.1

On 14.06.2024 08:31, Federico Serafini wrote:
> --- a/automation/eclair_analysis/ECLAIR/deviations.ecl
> +++ b/automation/eclair_analysis/ECLAIR/deviations.ecl
> @@ -413,6 +413,10 @@ explicit comment indicating the fallthrough intention is present."
>  -config=MC3R1.R17.1,macros+={hide , "^va_(arg|start|copy|end)$"}
>  -doc_end
>  
> +-doc_begin="Not using the return value of a function do not endanger safety if it coincides with the first actual argument."
> +-config=MC3R1.R17.7,calls+={safe, "any()", "decl(name(__builtin_memcpy||__builtin_memmove||__builtin_memset||cpumask_check))"}

While correct here, ...

> --- a/docs/misra/deviations.rst
> +++ b/docs/misra/deviations.rst
> @@ -364,6 +364,15 @@ Deviations related to MISRA C:2012 Rules:
>         by `stdarg.h`.
>       - Tagged as `deliberate` for ECLAIR.
>  
> +   * - R17.7
> +     - Not using the return value of a function do not endanger safety if it
> +       coincides with the first actual argument.
> +     - Tagged as `safe` for ECLAIR. Such functions are:
> +         - __builtin_memcpy()
> +         - __builtin_memmove()
> +         - __builtin_memset()
> +         - __cpumask_check()

... there are stray leading underscores on the last one here. With that
adjustment (and perhaps "s/ do / does /") the deviations.rst change would then
look okay to me, but I don't feel competent to ack deviations.ecl changes.

Still, as another question: Is it really relevant here that the argument in
question is specifically the 1st one?

Jan