From ea083911b1dc609506dd715b82f75759f7807c31 Mon Sep 17 00:00:00 2001
From: Nicola Vetrini <nicola.vetrini@bugseng.com>
Date: Wed, 11 Oct 2023 15:03:49 +0200
Subject: [PATCH] xen/include: make enum perfcounter anonymous

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>
---
 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 6efe66195d..aa65eb4dd0 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 7c5ce537bd..96022c0748 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
 };