| Message ID | d739fefde6f142cec10899ed2c5eb81f91618bf0.1697028983.git.nicola.vetrini@bugseng.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [XEN,for-4.19] xen/include: make enum perfcounter anonymous | expand |
On 11/10/2023 15:03, Nicola Vetrini wrote: > Using enumerators declared in a named enum, such as the one modified, > as operands to arithmetic operators is not allowed by MISRA C:2012 Rule > 10.1. > The enumerators of an anonymous enum can be used instead. > > Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com> > --- > This violation manifeststs itself, for instance, in all uses of macro > 'perfc_incra' from xen/include/xen/perfc.h, because the expansion > contains an arithmetic operation on two enum constants from enum > perfcounter. > > ( (*nr) <= PERFC_LAST_hypercalls - PERFC_hypercalls ? [...] > > --- > docs/misra/rules.rst | 3 +++ > xen/include/xen/perfc.h | 2 +- > 2 files changed, 4 insertions(+), 1 deletion(-) > > diff --git a/docs/misra/rules.rst b/docs/misra/rules.rst > index 3139ca7ae6dd..26c3ff819948 100644 > --- a/docs/misra/rules.rst > +++ b/docs/misra/rules.rst > @@ -341,6 +341,9 @@ maintainers if you want to suggest a change. > compilers' extensions) > - Implicit conversions to boolean for conditionals (?: if > while > for) and logical operators (! || &&) > + - The essential type model allows the constants defined by > anonymous > + enums (e.g., enum { A, B, C }) to be used as operands to > arithmetic > + operators, as they have a signed essential type. > > * - `Rule 10.2 > <https://gitlab.com/MISRA/MISRA-C/MISRA-C-2012/Example-Suite/-/blob/master/R_10_02.c>`_ > - Required > diff --git a/xen/include/xen/perfc.h b/xen/include/xen/perfc.h > index 7c5ce537bd02..96022c07481e 100644 > --- a/xen/include/xen/perfc.h > +++ b/xen/include/xen/perfc.h > @@ -39,7 +39,7 @@ > #define PERFSTATUS PERFCOUNTER > #define PERFSTATUS_ARRAY PERFCOUNTER_ARRAY > > -enum perfcounter { > +enum { > #include <xen/perfc_defn.h> > NUM_PERFCOUNTERS > }; > -- > 2.34.1 See [1] for a discussion on the possible alternatives to this approach. [1] https://marc.info/?l=xen-devel&m=169658364229813
On Wed, 11 Oct 2023, Nicola Vetrini wrote: > Using enumerators declared in a named enum, such as the one modified, > as operands to arithmetic operators is not allowed by MISRA C:2012 Rule 10.1. > The enumerators of an anonymous enum can be used instead. > > Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> > --- > This violation manifeststs itself, for instance, in all uses of macro > 'perfc_incra' from xen/include/xen/perfc.h, because the expansion > contains an arithmetic operation on two enum constants from enum perfcounter. > > ( (*nr) <= PERFC_LAST_hypercalls - PERFC_hypercalls ? [...] > > --- > docs/misra/rules.rst | 3 +++ > xen/include/xen/perfc.h | 2 +- > 2 files changed, 4 insertions(+), 1 deletion(-) > > diff --git a/docs/misra/rules.rst b/docs/misra/rules.rst > index 3139ca7ae6dd..26c3ff819948 100644 > --- a/docs/misra/rules.rst > +++ b/docs/misra/rules.rst > @@ -341,6 +341,9 @@ maintainers if you want to suggest a change. > compilers' extensions) > - Implicit conversions to boolean for conditionals (?: if while > for) and logical operators (! || &&) > + - The essential type model allows the constants defined by anonymous > + enums (e.g., enum { A, B, C }) to be used as operands to arithmetic > + operators, as they have a signed essential type. > > * - `Rule 10.2 <https://gitlab.com/MISRA/MISRA-C/MISRA-C-2012/Example-Suite/-/blob/master/R_10_02.c>`_ > - Required > diff --git a/xen/include/xen/perfc.h b/xen/include/xen/perfc.h > index 7c5ce537bd02..96022c07481e 100644 > --- a/xen/include/xen/perfc.h > +++ b/xen/include/xen/perfc.h > @@ -39,7 +39,7 @@ > #define PERFSTATUS PERFCOUNTER > #define PERFSTATUS_ARRAY PERFCOUNTER_ARRAY > > -enum perfcounter { > +enum { > #include <xen/perfc_defn.h> > NUM_PERFCOUNTERS > }; > -- > 2.34.1 >
diff --git a/docs/misra/rules.rst b/docs/misra/rules.rst index 3139ca7ae6dd..26c3ff819948 100644 --- a/docs/misra/rules.rst +++ b/docs/misra/rules.rst @@ -341,6 +341,9 @@ maintainers if you want to suggest a change. compilers' extensions) - Implicit conversions to boolean for conditionals (?: if while for) and logical operators (! || &&) + - The essential type model allows the constants defined by anonymous + enums (e.g., enum { A, B, C }) to be used as operands to arithmetic + operators, as they have a signed essential type. * - `Rule 10.2 <https://gitlab.com/MISRA/MISRA-C/MISRA-C-2012/Example-Suite/-/blob/master/R_10_02.c>`_ - Required diff --git a/xen/include/xen/perfc.h b/xen/include/xen/perfc.h index 7c5ce537bd02..96022c07481e 100644 --- a/xen/include/xen/perfc.h +++ b/xen/include/xen/perfc.h @@ -39,7 +39,7 @@ #define PERFSTATUS PERFCOUNTER #define PERFSTATUS_ARRAY PERFCOUNTER_ARRAY -enum perfcounter { +enum { #include <xen/perfc_defn.h> NUM_PERFCOUNTERS };
Using enumerators declared in a named enum, such as the one modified, as operands to arithmetic operators is not allowed by MISRA C:2012 Rule 10.1. The enumerators of an anonymous enum can be used instead. Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com> --- This violation manifeststs itself, for instance, in all uses of macro 'perfc_incra' from xen/include/xen/perfc.h, because the expansion contains an arithmetic operation on two enum constants from enum perfcounter. ( (*nr) <= PERFC_LAST_hypercalls - PERFC_hypercalls ? [...] --- docs/misra/rules.rst | 3 +++ xen/include/xen/perfc.h | 2 +- 2 files changed, 4 insertions(+), 1 deletion(-) -- 2.34.1