Mailing List Archive

[xen staging] automation/eclair: add deviations for Rule 20.7
commit 80d28865e181ae51d2a2f7cea5f0332ea5d845ee
Author: Nicola Vetrini <nicola.vetrini@bugseng.com>
AuthorDate: Fri Mar 29 10:11:33 2024 +0100
Commit: Stefano Stabellini <stefano.stabellini@amd.com>
CommitDate: Fri Apr 5 11:15:47 2024 -0700

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 | 25 ++++++++++++++++++++++--
docs/misra/deviations.rst | 14 ++++++++++++-
docs/misra/rules.rst | 2 +-
3 files changed, 37 insertions(+), 4 deletions(-)

diff --git a/automation/eclair_analysis/ECLAIR/deviations.ecl b/automation/eclair_analysis/ECLAIR/deviations.ecl
index de9ba723fb..70756503f5 100644
--- a/automation/eclair_analysis/ECLAIR/deviations.ecl
+++ b/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
diff --git a/docs/misra/deviations.rst b/docs/misra/deviations.rst
index eb5ef2bd9d..5fdacfd420 100644
--- a/docs/misra/deviations.rst
+++ b/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
diff --git a/docs/misra/rules.rst b/docs/misra/rules.rst
index 79487cf91c..86f4ad0ab3 100644
--- a/docs/misra/rules.rst
+++ b/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
--
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