| Message ID | 20230615211922.1328972-1-sstabellini@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v5] docs/misra: new rules addition | expand |
Hi Stefano, > On 15 Jun 2023, at 23:19, Stefano Stabellini <sstabellini@kernel.org> wrote: > > From: Stefano Stabellini <stefano.stabellini@amd.com> > > For Dir 1.1, a document describing all implementation-defined behaviour > (i.e. gcc-specific behavior) will be added to docs/misra, also including > implementation-specific (gcc-specific) appropriate types for bit-field > relevant to Rule 6.1. > > Rule 21.21 is lacking an example on gitlab but the rule is > straightforward: we don't use stdlib at all in Xen. > > Signed-off-by: Stefano Stabellini <stefano.stabellini@amd.com> > Reviewed-by: Michal Orzel <michal.orzel@amd.com> Reviewed-by: Bertrand Marquis <bertrand.marquis@arm.com> Cheers Bertrand > --- > Changes in v5: > - clarify suggested approach to Rule 7.2 > - add link for 21.21 > > Changes in v4: > - improve wording of the note in 6.1 > > Changes in v3: > - add all signed integer types to the Notes of 6.1 > - clarify 7.2 in the Notes > - not added: marking "inapplicable" rules, to be a separate patch > > Changes in v2: > - drop 5.6 > - specify additional appropriate types for 6.1 > > iii > --- > docs/misra/rules.rst | 50 ++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 50 insertions(+) > > diff --git a/docs/misra/rules.rst b/docs/misra/rules.rst > index d5a6ee8cb6..a88c284e7d 100644 > --- a/docs/misra/rules.rst > +++ b/docs/misra/rules.rst > @@ -40,6 +40,12 @@ existing codebase are work-in-progress. > - Summary > - Notes > > + * - `Dir 1.1 <https://gitlab.com/MISRA/MISRA-C/MISRA-C-2012/Example-Suite/-/blob/master/D_01_01.c>`_ > + - Required > + - Any implementation-defined behaviour on which the output of the > + program depends shall be documented and understood > + - > + > * - `Dir 2.1 <https://gitlab.com/MISRA/MISRA-C/MISRA-C-2012/Example-Suite/-/blob/master/D_02_01.c>`_ > - Required > - All source files shall compile without any compilation errors > @@ -57,6 +63,13 @@ existing codebase are work-in-progress. > header file being included more than once > - > > + * - `Dir 4.11 <https://gitlab.com/MISRA/MISRA-C/MISRA-C-2012/Example-Suite/-/blob/master/D_04_11.c>`_ > + - Required > + - The validity of values passed to library functions shall be checked > + - We do not have libraries in Xen (libfdt and others are not > + considered libraries from MISRA C point of view as they are > + imported in source form) > + > * - `Dir 4.14 <https://gitlab.com/MISRA/MISRA-C/MISRA-C-2012/Example-Suite/-/blob/master/D_04_14.c>`_ > - Required > - The validity of values received from external sources shall be > @@ -133,6 +146,12 @@ existing codebase are work-in-progress. > headers (xen/include/public/) are allowed to retain longer > identifiers for backward compatibility. > > + * - `Rule 6.1 <https://gitlab.com/MISRA/MISRA-C/MISRA-C-2012/Example-Suite/-/blob/master/R_06_01.c>`_ > + - Required > + - Bit-fields shall only be declared with an appropriate type > + - In addition to the C99 types, we also consider appropriate types > + enum and all explicitly signed / unsigned integer types. > + > * - `Rule 6.2 <https://gitlab.com/MISRA/MISRA-C/MISRA-C-2012/Example-Suite/-/blob/master/R_06_02.c>`_ > - Required > - Single-bit named bit fields shall not be of a signed type > @@ -143,6 +162,32 @@ existing codebase are work-in-progress. > - Octal constants shall not be used > - > > + * - `Rule 7.2 <https://gitlab.com/MISRA/MISRA-C/MISRA-C-2012/Example-Suite/-/blob/master/R_07_02.c>`_ > + - Required > + - A "u" or "U" suffix shall be applied to all integer constants > + that are represented in an unsigned type > + - The rule asks that any integer literal that is implicitly > + unsigned is made explicitly unsigned by using one of the > + indicated suffixes. As an example, on a machine where the int > + type is 32-bit wide, 0x77777777 is signed whereas 0x80000000 is > + (implicitly) unsigned. In order to comply with the rule, the > + latter should be rewritten as either 0x80000000u or 0x80000000U. > + Consistency considerations may suggest using the same suffix even > + when not required by the rule. For instance, if one has: > + > + Original: f(0x77777777); f(0x80000000); > + > + one should do > + > + Solution 1: f(0x77777777U); f(0x80000000U); > + > + over > + > + Solution 2: f(0x77777777); f(0x80000000U); > + > + after having ascertained that "Solution 1" is compatible with the > + intended semantics. > + > * - `Rule 7.3 <https://gitlab.com/MISRA/MISRA-C/MISRA-C-2012/Example-Suite/-/blob/master/R_07_03.c>`_ > - Required > - The lowercase character l shall not be used in a literal suffix > @@ -314,6 +359,11 @@ existing codebase are work-in-progress. > used following a subsequent call to the same function > - > > + * - `Rule 21.21 <https://gitlab.com/MISRA/MISRA-C/MISRA-C-2012/Example-Suite/>`_ > + - Required > + - The Standard Library function system of <stdlib.h> shall not be used > + - > + > * - `Rule 22.2 <https://gitlab.com/MISRA/MISRA-C/MISRA-C-2012/Example-Suite/-/blob/master/R_22_02.c>`_ > - Mandatory > - A block of memory shall only be freed if it was allocated by means of a > -- > 2.25.1 >
diff --git a/docs/misra/rules.rst b/docs/misra/rules.rst index d5a6ee8cb6..a88c284e7d 100644 --- a/docs/misra/rules.rst +++ b/docs/misra/rules.rst @@ -40,6 +40,12 @@ existing codebase are work-in-progress. - Summary - Notes + * - `Dir 1.1 <https://gitlab.com/MISRA/MISRA-C/MISRA-C-2012/Example-Suite/-/blob/master/D_01_01.c>`_ + - Required + - Any implementation-defined behaviour on which the output of the + program depends shall be documented and understood + - + * - `Dir 2.1 <https://gitlab.com/MISRA/MISRA-C/MISRA-C-2012/Example-Suite/-/blob/master/D_02_01.c>`_ - Required - All source files shall compile without any compilation errors @@ -57,6 +63,13 @@ existing codebase are work-in-progress. header file being included more than once - + * - `Dir 4.11 <https://gitlab.com/MISRA/MISRA-C/MISRA-C-2012/Example-Suite/-/blob/master/D_04_11.c>`_ + - Required + - The validity of values passed to library functions shall be checked + - We do not have libraries in Xen (libfdt and others are not + considered libraries from MISRA C point of view as they are + imported in source form) + * - `Dir 4.14 <https://gitlab.com/MISRA/MISRA-C/MISRA-C-2012/Example-Suite/-/blob/master/D_04_14.c>`_ - Required - The validity of values received from external sources shall be @@ -133,6 +146,12 @@ existing codebase are work-in-progress. headers (xen/include/public/) are allowed to retain longer identifiers for backward compatibility. + * - `Rule 6.1 <https://gitlab.com/MISRA/MISRA-C/MISRA-C-2012/Example-Suite/-/blob/master/R_06_01.c>`_ + - Required + - Bit-fields shall only be declared with an appropriate type + - In addition to the C99 types, we also consider appropriate types + enum and all explicitly signed / unsigned integer types. + * - `Rule 6.2 <https://gitlab.com/MISRA/MISRA-C/MISRA-C-2012/Example-Suite/-/blob/master/R_06_02.c>`_ - Required - Single-bit named bit fields shall not be of a signed type @@ -143,6 +162,32 @@ existing codebase are work-in-progress. - Octal constants shall not be used - + * - `Rule 7.2 <https://gitlab.com/MISRA/MISRA-C/MISRA-C-2012/Example-Suite/-/blob/master/R_07_02.c>`_ + - Required + - A "u" or "U" suffix shall be applied to all integer constants + that are represented in an unsigned type + - The rule asks that any integer literal that is implicitly + unsigned is made explicitly unsigned by using one of the + indicated suffixes. As an example, on a machine where the int + type is 32-bit wide, 0x77777777 is signed whereas 0x80000000 is + (implicitly) unsigned. In order to comply with the rule, the + latter should be rewritten as either 0x80000000u or 0x80000000U. + Consistency considerations may suggest using the same suffix even + when not required by the rule. For instance, if one has: + + Original: f(0x77777777); f(0x80000000); + + one should do + + Solution 1: f(0x77777777U); f(0x80000000U); + + over + + Solution 2: f(0x77777777); f(0x80000000U); + + after having ascertained that "Solution 1" is compatible with the + intended semantics. + * - `Rule 7.3 <https://gitlab.com/MISRA/MISRA-C/MISRA-C-2012/Example-Suite/-/blob/master/R_07_03.c>`_ - Required - The lowercase character l shall not be used in a literal suffix @@ -314,6 +359,11 @@ existing codebase are work-in-progress. used following a subsequent call to the same function - + * - `Rule 21.21 <https://gitlab.com/MISRA/MISRA-C/MISRA-C-2012/Example-Suite/>`_ + - Required + - The Standard Library function system of <stdlib.h> shall not be used + - + * - `Rule 22.2 <https://gitlab.com/MISRA/MISRA-C/MISRA-C-2012/Example-Suite/-/blob/master/R_22_02.c>`_ - Mandatory - A block of memory shall only be freed if it was allocated by means of a