On 16/10/2023 17:33, Jan Beulich wrote:
On 12.10.2023 17:28, Nicola Vetrini wrote:
--- a/automation/eclair_analysis/ECLAIR/deviations.ecl
+++ b/automation/eclair_analysis/ECLAIR/deviations.ecl
@@ -274,6 +274,12 @@ still non-negative."
-config=MC3R1.R10.1,etypes+={safe,
"stmt(operator(logical)||node(conditional_operator||binary_conditional_operator))",
"dst_type(ebool||boolean)"}
-doc_end
+-doc_begin="The macro LOWEST_BIT encapsulates a well-known pattern to
obtain the value
+2^ffs(x) for unsigned integers on two's complement architectures
+(all the architectures supported by Xen satisfy this requirement)."
+-config=MC3R1.R10.1,reports+={safe,
"any_area(any_loc(any_exp(macro(^LOWEST_BIT$))))"}
+-doc_end
Why is this added here rather than by ...
--- a/xen/include/xen/macros.h
+++ b/xen/include/xen/macros.h
@@ -8,8 +8,10 @@
#define DIV_ROUND(n, d) (((n) + (d) / 2) / (d))
#define DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d))
-#define MASK_EXTR(v, m) (((v) & (m)) / ((m) & -(m)))
-#define MASK_INSR(v, m) (((v) * ((m) & -(m))) & (m))
a SAF-<n>-safe comment here?
One reason is that now that violations only belonging to tool
configurations
and similar are documented in docs/misra/deviations.rst (committed in
Stefano's
branch for-4.19 [1]). Also, there were disagreements on the SAF naming
scheme, and
patches like those would not be accepted at the moment.
+#define LOWEST_BIT(x) ((x) & -(x))
Personally I consider the name misleading: I'd expect a macro of this
name to return a bit number, not a mask with a single bit set. No
good, reasonably short name comes to mind - ISOLATE_LOW_BIT() is too
long for my taste.
Jan
[1]
https://gitlab.com/xen-project/people/sstabellini/xen/-/commits/for-4.19
--
Nicola Vetrini, BSc
Software Engineer, BUGSENG srl (https://bugseng.com)
