automation/eclair: add deviations for Rule 20.7

These deviations deal with the following cases:
- macro arguments used directly as initializer list arguments;
- uses of the __config_enabled macro, that can't be brought
  into compliance without breaking its functionality;
- exclude files that are out of scope (efi headers and cpu_idle);
- uses of alternative_{call,vcall}[0-9] macros.

The existing configuration for R20.7 is reordered so that it matches the
cases listed in its documentation comment.

Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>

automation/eclair_analysis/ECLAIR/deviations.ecl

@@ -401,12 +401,33 @@ unexpected result when the structure is given as argument to a sizeof() operator
 
 -doc_begin="Code violating Rule 20.7 is safe when macro parameters are used: (1)
 as function arguments; (2) as macro arguments; (3) as array indices; (4) as lhs
-in assignments."
+in assignments; (5) as initializers, possibly designated, in initalizer lists."
 -config=MC3R1.R20.7,expansion_context=
 {safe, "context(__call_expr_arg_contexts)"},
+{safe, "left_right(^[(,\\[]$,^[),\\]]$)"},
 {safe, "context(skip_to(__expr_non_syntactic_contexts, stmt_child(node(array_subscript_expr), subscript)))"},
 {safe, "context(skip_to(__expr_non_syntactic_contexts, stmt_child(operator(assign), lhs)))"},
-{safe, "left_right(^[(,\\[]$,^[),\\]]$)"}
+{safe, "context(skip_to(__expr_non_syntactic_contexts, stmt_child(node(init_list_expr||designated_init_expr), init)))"}
+-doc_end
+
+-doc_begin="Violations involving the __config_enabled macros cannot be fixed without
+breaking the macro's logic; futhermore, the macro is only ever used in the context
+of the IS_ENABLED or STATIC_IF/STATIC_IF_NOT macros, so it always receives a literal
+0 or 1 as input, posing no risk to safety."
+-config=MC3R1.R20.7,reports+={safe, "any_area(any_loc(any_exp(macro(^___config_enabled$))))"}
+-doc_end
+
+-doc_begin="Violations due to the use of macros defined in files that are
+not in scope for compliance are allowed, as that is imported code."
+-file_tag+={gnu_efi_include, "^xen/include/efi/.*$"}
+-file_tag+={acpi_cpu_idle, "^xen/arch/x86/acpi/cpu_idle\\.c$"}
+-config=MC3R1.R20.7,reports+={safe, "any_area(any_loc(file(gnu_efi_include)))"}
+-config=MC3R1.R20.7,reports+={safe, "any_area(any_loc(file(acpi_cpu_idle)))"}
+-doc_end
+
+-doc_begin="To avoid compromising readability, the macros alternative_(v)?call[0-9] are allowed
+not to parenthesize their arguments."
+-config=MC3R1.R20.7,reports+={safe, "any_area(any_loc(any_exp(macro(^alternative_(v)?call[0-9]$))))"}
 -doc_end
 
 -doc_begin="Uses of variadic macros that have one of their arguments defined as

docs/misra/deviations.rst

@@ -345,7 +345,19 @@ Deviations related to MISRA C:2012 Rules:
        (1) as function arguments;
        (2) as macro arguments;
        (3) as array indices;
-       (4) as lhs in assignments.
+       (4) as lhs in assignments;
+       (5) as initializers, possibly designated, in initalizer lists.
+     - Tagged as `safe` for ECLAIR.
+
+   * - R20.7
+     - Violations due to the use of macros defined in files that are not
+       in scope for compliance are allowed, as that is imported code.
+     - Tagged as `safe` for ECLAIR.
+
+   * - R20.7
+     - To avoid compromising readability, the macros `alternative_(v)?call[0-9]`
+       are allowed not to parenthesize their arguments, as there are already
+       sanity checks in place.
      - Tagged as `safe` for ECLAIR.
 
    * - R20.12

docs/misra/rules.rst

@@ -561,7 +561,7 @@ maintainers if you want to suggest a change.
        shall be enclosed in parentheses
      - Extra parentheses are not required when macro parameters are used
        as function arguments, as macro arguments, array indices, lhs in
-       assignments
+       assignments or as initializers in initalizer lists.
 
    * - `Rule 20.9 <https://gitlab.com/MISRA/MISRA-C/MISRA-C-2012/Example-Suite/-/blob/master/R_20_09.c>`_
      - Required