automation/eclair: configure Rule 13.6 and custom service B.UNEVALEFF

Rule 13.6 states that "The operand of the `sizeof' operator shall not
contain any expression which has potential side effects".

Define service B.UNEVALEFF as an extension of Rule 13.6 to
check for unevalued side effects also for typeof and alignof operators.

Update ECLAIR configuration to deviate uses of BUILD_BUG_ON and
alternative_v?call[0-9] for both Rule 13.6 and B.UNEVALEFF.

Add service B.UNEVALEFF to the accepted.ecl guidelines to check
"violations" in the weekly analysis.

Signed-off-by: Federico Serafini <federico.serafini@bugseng.com>
Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Release-Acked-By: Oleksii Kurochko <oleksii.kurochko@gmail.com>

automation/eclair_analysis/ECLAIR/B.UNEVALEFF.ecl

@@ -0,0 +1,10 @@
+-clone_service=MC3R1.R13.6,B.UNEVALEFF
+
+-config=B.UNEVALEFF,summary="The operand of the `alignof' and `typeof'  operators shall not contain any expression which has potential side effects"
+-config=B.UNEVALEFF,stmt_child_matcher=
+{"stmt(node(utrait_expr)&&operator(alignof))", expr, 0, "stmt(any())", {}},
+{"stmt(node(utrait_type)&&operator(alignof))", type, 0, "stmt(any())", {}},
+{"stmt(node(utrait_expr)&&operator(preferred_alignof))", expr, 0, "stmt(any())", {}},
+{"stmt(node(utrait_type)&&operator(preferred_alignof))", type, 0, "stmt(any())", {}},
+{"type(node(typeof_expr))", expr, 0, "stmt(any())", {}},
+{"type(node(typeof_type))", type, 0, "stmt(any())", {}}

automation/eclair_analysis/ECLAIR/accepted_guidelines.sh

@@ -11,3 +11,5 @@ accepted_rst=$1
 
 grep -Eo "\`(Dir|Rule) [0-9]+\.[0-9]+" ${accepted_rst} \
      | sed -e 's/`Rule /MC3R1.R/' -e  's/`Dir /MC3R1.D/' -e 's/.*/-enable=&/' > ${script_dir}/accepted.ecl
+
+echo "-enable=B.UNEVALEFF" >> ${script_dir}/accepted.ecl

automation/eclair_analysis/ECLAIR/analysis.ecl

@@ -52,6 +52,7 @@ their Standard Library equivalents."
 -eval_file=adopted.ecl
 -eval_file=out_of_scope.ecl
 
+-eval_file=B.UNEVALEFF.ecl
 -eval_file=deviations.ecl
 -eval_file=call_properties.ecl
 -eval_file=tagging.ecl

automation/eclair_analysis/ECLAIR/deviations.ecl

@@ -344,6 +344,16 @@ of the short-circuit evaluation strategy of such logical operators."
 -config=MC3R1.R13.5,reports+={disapplied,"any()"}
 -doc_end
 
+-doc_begin="Macros alternative_v?call[0-9] use sizeof and typeof to check that the argument types match the corresponding parameter ones."
+-config=MC3R1.R13.6,reports+={deliberate,"any_area(any_loc(any_exp(macro(^alternative_vcall[0-9]$))&&file(^xen/arch/x86/include/asm/alternative\\.h*$)))"}
+-config=B.UNEVALEFF,reports+={deliberate,"any_area(any_loc(any_exp(macro(^alternative_v?call[0-9]$))&&file(^xen/arch/x86/include/asm/alterantive\\.h*$)))"}
+-doc_end
+
+-doc_begin="Anything, no matter how complicated, inside the BUILD_BUG_ON macro is subject to a compile-time evaluation without relevant side effects."
+-config=MC3R1.R13.6,reports+={safe,"any_area(any_loc(any_exp(macro(name(BUILD_BUG_ON)))))"}
+-config=B.UNEVALEFF,reports+={safe,"any_area(any_loc(any_exp(macro(name(BUILD_BUG_ON)))))"}
+-doc_end
+
 #
 # Series 14
 #

docs/misra/deviations.rst

@@ -300,6 +300,16 @@ Deviations related to MISRA C:2012 Rules:
        the short-circuit evaluation strategy for logical operators.
      - Project-wide deviation; tagged as `disapplied` for ECLAIR.
 
+   * - R13.6
+     - On x86, macros alternative_v?call[0-9] use sizeof and typeof to check
+       that the argument types match the corresponding parameter ones.
+     - Tagged as `deliberate` for ECLAIR.
+
+   * - R13.6
+     - Anything, no matter how complicated, inside the BUILD_BUG_ON macro is
+       subject to a compile-time evaluation without relevant side effects."
+     - Tagged as `safe` for ECLAIR.
+
    * - R14.2
      - The severe restrictions imposed by this rule on the use of 'for'
        statements are not counterbalanced by the presumed facilitation of the