| Message ID | 892be5c403ca7a20b35fb9facacb6a38bc7f6bfe.1707900742.git.nicola.vetrini@bugseng.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [XEN] automation/eclair_analysis: deviate certain macros for Rule 20.12 | expand |
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
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.
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: -----------------
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(+)