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>
---
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
--
2.25.1Hi 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 >
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