.../eclair_analysis/ECLAIR/deviations.ecl | 10 ++++++++++ docs/misra/deviations.rst | 18 ++++++++++++++++++ 2 files changed, 28 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>
---
This patch is intended as a follow-up to the patch accepting this Rule for Xen
---
.../eclair_analysis/ECLAIR/deviations.ecl | 10 ++++++++++
docs/misra/deviations.rst | 18 ++++++++++++++++++
2 files changed, 28 insertions(+)
diff --git a/automation/eclair_analysis/ECLAIR/deviations.ecl b/automation/eclair_analysis/ECLAIR/deviations.ecl
index fd32ff8a9cae..98e5ad146b8d 100644
--- a/automation/eclair_analysis/ECLAIR/deviations.ecl
+++ b/automation/eclair_analysis/ECLAIR/deviations.ecl
@@ -387,6 +387,16 @@ in assignments."
{safe, "left_right(^[(,\\[]$,^[),\\]]$)"}
-doc_end
+-doc_begin="The token pasting in variadic macros cannot be replaced."
+-config=MC3R1.R20.12,macros+={deliberate, "variadic()"}
+-doc_end
+
+-doc_begin="Uses of # and ## operators within the following macros are
+deliberate."
+-config=MC3R1.R20.12,macros+={deliberate, "name(ASSERT||BUILD_BUG_ON||BUILD_BUG_ON_ZERO||GENERATE_CASE)"}
+-doc_end
+
+
#
# General
#
diff --git a/docs/misra/deviations.rst b/docs/misra/deviations.rst
index 123c78e20a01..855c1c5579bb 100644
--- a/docs/misra/deviations.rst
+++ b/docs/misra/deviations.rst
@@ -330,6 +330,24 @@ 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.
+ - 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 special-purpose 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.
+ - Tagged as `deliberate` for ECLAIR.
+
Other deviations:
-----------------
--
2.34.1
On 14.02.2024 12:26, Nicola Vetrini wrote: > --- a/automation/eclair_analysis/ECLAIR/deviations.ecl > +++ b/automation/eclair_analysis/ECLAIR/deviations.ecl > @@ -387,6 +387,16 @@ in assignments." > {safe, "left_right(^[(,\\[]$,^[),\\]]$)"} > -doc_end > > +-doc_begin="The token pasting in variadic macros cannot be replaced." > +-config=MC3R1.R20.12,macros+={deliberate, "variadic()"} > +-doc_end > + > +-doc_begin="Uses of # and ## operators within the following macros are > +deliberate." I don't think this is a good explanation. The use of those operators is deliberate elsewhere as well. > +-config=MC3R1.R20.12,macros+={deliberate, "name(ASSERT||BUILD_BUG_ON||BUILD_BUG_ON_ZERO||GENERATE_CASE)"} I said in another context already that it is necessary to separate global scope macros from local helper ones. Any CU can introduce another GENERATE_CASE(), and would be deviated here right away. In fact I question applicability of the deviation to arm/arm64/vsysreg.c; I only see it as applicable to arm/vcpreg.c. Jan
On 2024-02-14 12:49, Jan Beulich wrote: > On 14.02.2024 12:26, Nicola Vetrini wrote: >> --- a/automation/eclair_analysis/ECLAIR/deviations.ecl >> +++ b/automation/eclair_analysis/ECLAIR/deviations.ecl >> @@ -387,6 +387,16 @@ in assignments." >> {safe, "left_right(^[(,\\[]$,^[),\\]]$)"} >> -doc_end >> >> +-doc_begin="The token pasting in variadic macros cannot be replaced." >> +-config=MC3R1.R20.12,macros+={deliberate, "variadic()"} >> +-doc_end >> + >> +-doc_begin="Uses of # and ## operators within the following macros >> are >> +deliberate." > > I don't think this is a good explanation. The use of those operators is > deliberate elsewhere as well. > Implicitly this was intended to be delimited to its applicability scope - violations of Rule 20.12. I detailed the reasons that were brought up to keep using these macros as is in the deviations.rst file. I'm open to further refinements, though. >> +-config=MC3R1.R20.12,macros+={deliberate, >> "name(ASSERT||BUILD_BUG_ON||BUILD_BUG_ON_ZERO||GENERATE_CASE)"} > > I said in another context already that it is necessary to separate > global scope macros from local helper ones. Any CU can introduce > another > GENERATE_CASE(), and would be deviated here right away. In fact I > question applicability of the deviation to arm/arm64/vsysreg.c; I only > see it as applicable to arm/vcpreg.c. > Why wouldn't this be applicable for vsysreg.c? I can certainly fine-tune the deviation, if needed -- Nicola Vetrini, BSc Software Engineer, BUGSENG srl (https://bugseng.com)
On 14.02.2024 16:31, Nicola Vetrini wrote: > On 2024-02-14 12:49, Jan Beulich wrote: >> On 14.02.2024 12:26, Nicola Vetrini wrote: >>> +-config=MC3R1.R20.12,macros+={deliberate, >>> "name(ASSERT||BUILD_BUG_ON||BUILD_BUG_ON_ZERO||GENERATE_CASE)"} >> >> I said in another context already that it is necessary to separate >> global scope macros from local helper ones. Any CU can introduce >> another >> GENERATE_CASE(), and would be deviated here right away. In fact I >> question applicability of the deviation to arm/arm64/vsysreg.c; I only >> see it as applicable to arm/vcpreg.c. > > Why wouldn't this be applicable for vsysreg.c? I can certainly fine-tune > the deviation, if needed There the sole macro parameter is used in only one of the possible ways, with ##, unless I'm overlooking something. Aiui it is mixed use which would need a deviation. Jan
On 2024-02-14 16:45, Jan Beulich wrote: > On 14.02.2024 16:31, Nicola Vetrini wrote: >> On 2024-02-14 12:49, Jan Beulich wrote: >>> On 14.02.2024 12:26, Nicola Vetrini wrote: >>>> +-config=MC3R1.R20.12,macros+={deliberate, >>>> "name(ASSERT||BUILD_BUG_ON||BUILD_BUG_ON_ZERO||GENERATE_CASE)"} >>> >>> I said in another context already that it is necessary to separate >>> global scope macros from local helper ones. Any CU can introduce >>> another >>> GENERATE_CASE(), and would be deviated here right away. In fact I >>> question applicability of the deviation to arm/arm64/vsysreg.c; I >>> only >>> see it as applicable to arm/vcpreg.c. >> >> Why wouldn't this be applicable for vsysreg.c? I can certainly >> fine-tune >> the deviation, if needed > > There the sole macro parameter is used in only one of the possible > ways, > with ##, unless I'm overlooking something. Aiui it is mixed use which > would need a deviation. I see. In that case I'll restrict the deviation, thanks. -- Nicola Vetrini, BSc Software Engineer, BUGSENG srl (https://bugseng.com)
© 2016 - 2024 Red Hat, Inc.