.../eclair_analysis/ECLAIR/deviations.ecl | 20 +++++++++++++++++ docs/misra/deviations.rst | 22 +++++++++++++++++++ 2 files changed, 42 insertions(+)
Certain macros are allowed to violate the Rule, since their meaning and
intended use is well-known to all Xen developers.
Variadic macros that rely on the GCC extension for removing a trailing
comma when token pasting the variable argument are similarly
well-understood and therefore allowed.
No functional change.
Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
---
Changes in v2:
- Restrict deviation for GENERATE_CASE to vcpreg.c.
- Improve deviation justifications.
---
.../eclair_analysis/ECLAIR/deviations.ecl | 20 +++++++++++++++++
docs/misra/deviations.rst | 22 +++++++++++++++++++
2 files changed, 42 insertions(+)
diff --git a/automation/eclair_analysis/ECLAIR/deviations.ecl b/automation/eclair_analysis/ECLAIR/deviations.ecl
index fd32ff8a9cae..04cb41e16a50 100644
--- a/automation/eclair_analysis/ECLAIR/deviations.ecl
+++ b/automation/eclair_analysis/ECLAIR/deviations.ecl
@@ -387,6 +387,26 @@ in assignments."
{safe, "left_right(^[(,\\[]$,^[),\\]]$)"}
-doc_end
+-doc_begin="Uses of variadic macros that have one of their arguments defined as
+a macro and used within the body for both ordinary parameter expansion and as an
+operand to the # or ## operators have a behavior that is well-understood and
+deliberate."
+-config=MC3R1.R20.12,macros+={deliberate, "variadic()"}
+-doc_end
+
+-doc_begin="Uses of a macro parameter for ordinary expansion and as an operand
+to the # or ## operators within the following macros are deliberate, to provide
+useful diagnostic messages to the user."
+-config=MC3R1.R20.12,macros+={deliberate, "name(ASSERT||BUILD_BUG_ON||BUILD_BUG_ON_ZERO)"}
+-doc_end
+
+-doc_begin="The helper macro GENERATE_CASE may use a macro parameter for ordinary
+expansion and token pasting to improve readability. Only instances where this
+leads to a violation of the Rule are deviated."
+-file_tag+={deliberate_generate_case, "^xen/arch/arm/vcpreg\\.c$"}
+-config=MC3R1.R20.12,macros+={deliberate, "name(GENERATE_CASE)&&loc(file(deliberate_generate_case))"}
+-doc_end
+
#
# General
#
diff --git a/docs/misra/deviations.rst b/docs/misra/deviations.rst
index 123c78e20a01..84da637ef888 100644
--- a/docs/misra/deviations.rst
+++ b/docs/misra/deviations.rst
@@ -330,6 +330,28 @@ Deviations related to MISRA C:2012 Rules:
(4) as lhs in assignments.
- Tagged as `safe` for ECLAIR.
+ * - R20.12
+ - Variadic macros that use token pasting often employ the gcc extension
+ `ext_paste_comma`, as detailed in `C-language-toolchain.rst`, which is
+ not easily replaceable; macros that in addition perform regular argument
+ expansion on the same argument subject to the # or ## operators violate
+ the Rule if the argument is a macro.
+ - Tagged as `deliberate` for ECLAIR.
+
+ * - R20.12
+ - Macros that are used for runtime or build-time assertions contain
+ deliberate uses of an argument as both a regular argument and a
+ stringification token, to provide useful diagnostic messages.
+ - Tagged as `deliberate` for ECLAIR.
+
+ * - R20.12
+ - GENERATE_CASE is a local helper macro that allows some selected switch
+ statements to be more compact and readable. As such, the risk of
+ developer confusion in using such macro is deemed negligible. This
+ construct is deviated only in Translation Units that present a violation
+ of the Rule due to uses of this macro.
+ - Tagged as `deliberate` for ECLAIR.
+
Other deviations:
-----------------
--
2.34.1
On 2024-02-15 14:06, Nicola Vetrini wrote: > Certain macros are allowed to violate the Rule, since their meaning and > intended use is well-known to all Xen developers. > > Variadic macros that rely on the GCC extension for removing a trailing > comma when token pasting the variable argument are similarly > well-understood and therefore allowed. > > No functional change. > > Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com> > --- > Changes in v2: > - Restrict deviation for GENERATE_CASE to vcpreg.c. > - Improve deviation justifications. > --- > .../eclair_analysis/ECLAIR/deviations.ecl | 20 +++++++++++++++++ > docs/misra/deviations.rst | 22 +++++++++++++++++++ > 2 files changed, 42 insertions(+) > Hi, this patch has an R-by from Stefano. Is there something preventing this from being committed? -- Nicola Vetrini, BSc Software Engineer, BUGSENG srl (https://bugseng.com)
On Thu, 15 Feb 2024, Nicola Vetrini wrote: > Certain macros are allowed to violate the Rule, since their meaning and > intended use is well-known to all Xen developers. > > Variadic macros that rely on the GCC extension for removing a trailing > comma when token pasting the variable argument are similarly > well-understood and therefore allowed. > > No functional change. > > Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> > --- > Changes in v2: > - Restrict deviation for GENERATE_CASE to vcpreg.c. > - Improve deviation justifications. > --- > .../eclair_analysis/ECLAIR/deviations.ecl | 20 +++++++++++++++++ > docs/misra/deviations.rst | 22 +++++++++++++++++++ > 2 files changed, 42 insertions(+) > > diff --git a/automation/eclair_analysis/ECLAIR/deviations.ecl b/automation/eclair_analysis/ECLAIR/deviations.ecl > index fd32ff8a9cae..04cb41e16a50 100644 > --- a/automation/eclair_analysis/ECLAIR/deviations.ecl > +++ b/automation/eclair_analysis/ECLAIR/deviations.ecl > @@ -387,6 +387,26 @@ in assignments." > {safe, "left_right(^[(,\\[]$,^[),\\]]$)"} > -doc_end > > +-doc_begin="Uses of variadic macros that have one of their arguments defined as > +a macro and used within the body for both ordinary parameter expansion and as an > +operand to the # or ## operators have a behavior that is well-understood and > +deliberate." > +-config=MC3R1.R20.12,macros+={deliberate, "variadic()"} > +-doc_end > + > +-doc_begin="Uses of a macro parameter for ordinary expansion and as an operand > +to the # or ## operators within the following macros are deliberate, to provide > +useful diagnostic messages to the user." > +-config=MC3R1.R20.12,macros+={deliberate, "name(ASSERT||BUILD_BUG_ON||BUILD_BUG_ON_ZERO)"} > +-doc_end > + > +-doc_begin="The helper macro GENERATE_CASE may use a macro parameter for ordinary > +expansion and token pasting to improve readability. Only instances where this > +leads to a violation of the Rule are deviated." > +-file_tag+={deliberate_generate_case, "^xen/arch/arm/vcpreg\\.c$"} > +-config=MC3R1.R20.12,macros+={deliberate, "name(GENERATE_CASE)&&loc(file(deliberate_generate_case))"} > +-doc_end > + > # > # General > # > diff --git a/docs/misra/deviations.rst b/docs/misra/deviations.rst > index 123c78e20a01..84da637ef888 100644 > --- a/docs/misra/deviations.rst > +++ b/docs/misra/deviations.rst > @@ -330,6 +330,28 @@ Deviations related to MISRA C:2012 Rules: > (4) as lhs in assignments. > - Tagged as `safe` for ECLAIR. > > + * - R20.12 > + - Variadic macros that use token pasting often employ the gcc extension > + `ext_paste_comma`, as detailed in `C-language-toolchain.rst`, which is > + not easily replaceable; macros that in addition perform regular argument > + expansion on the same argument subject to the # or ## operators violate > + the Rule if the argument is a macro. > + - Tagged as `deliberate` for ECLAIR. > + > + * - R20.12 > + - Macros that are used for runtime or build-time assertions contain > + deliberate uses of an argument as both a regular argument and a > + stringification token, to provide useful diagnostic messages. > + - Tagged as `deliberate` for ECLAIR. > + > + * - R20.12 > + - GENERATE_CASE is a local helper macro that allows some selected switch > + statements to be more compact and readable. As such, the risk of > + developer confusion in using such macro is deemed negligible. This > + construct is deviated only in Translation Units that present a violation > + of the Rule due to uses of this macro. > + - Tagged as `deliberate` for ECLAIR. > + > Other deviations: > ----------------- > > -- > 2.34.1 >
On 2024-02-15 14:06, Nicola Vetrini wrote: > Certain macros are allowed to violate the Rule, since their meaning and > intended use is well-known to all Xen developers. > > Variadic macros that rely on the GCC extension for removing a trailing > comma when token pasting the variable argument are similarly > well-understood and therefore allowed. > > No functional change. > > Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com> > --- > Changes in v2: > - Restrict deviation for GENERATE_CASE to vcpreg.c. > - Improve deviation justifications. > --- > .../eclair_analysis/ECLAIR/deviations.ecl | 20 +++++++++++++++++ > docs/misra/deviations.rst | 22 +++++++++++++++++++ > 2 files changed, 42 insertions(+) > Ping? -- Nicola Vetrini, BSc Software Engineer, BUGSENG srl (https://bugseng.com)
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