[XEN PATCH v3 1/2] MISRA C:2012 Rule 17.1 states: The features of `<stdarg.h>' shall not be used

[Simone Ballarin <simone.ballarin@bugseng.com>]

The Xen community wants to avoid using variadic functions except for
specific circumstances where it feels appropriate by strict code review.

Add deviation for printf()-like functions.

Signed-off-by: Simone Ballarin <simone.ballarin@bugseng.com>

---
Changes in v3:
- use regex to exempt all .*printk and .*printf functions, instead
  of manually listing them one by one.
Changes in v2:
- replace "console output related" with "printf()-like".
---
 automation/eclair_analysis/ECLAIR/deviations.ecl | 13 +++++++++++++
 docs/misra/deviations.rst                        |  5 +++++
 2 files changed, 18 insertions(+)

diff --git a/automation/eclair_analysis/ECLAIR/deviations.ecl b/automation/eclair_analysis/ECLAIR/deviations.ecl
index de9ba723fb..936c738caf 100644
--- a/automation/eclair_analysis/ECLAIR/deviations.ecl
+++ b/automation/eclair_analysis/ECLAIR/deviations.ecl
@@ -386,6 +386,19 @@ explicit comment indicating the fallthrough intention is present."
 -config=MC3R1.R16.6,switch_clauses+={deliberate, "default(0)"}
 -doc_end
 
+#
+# Series 17.
+#
+
+-doc_begin="printf()-like functions are allowed to use the variadic features provided by stdarg.h."
+-config=MC3R1.R17.1,reports+={deliberate,"any_area(^.*va_list.*$&&context(ancestor_or_self(^.*printk\(.*\)$)))"}
+-config=MC3R1.R17.1,reports+={deliberate,"any_area(^.*va_list.*$&&context(ancestor_or_self(^.*printf\(.*\)$)))"}
+-config=MC3R1.R17.1,reports+={deliberate,"any_area(^.*va_list.*$&&context(ancestor_or_self(name(panic)&&kind(function))))"}
+-config=MC3R1.R17.1,reports+={deliberate,"any_area(^.*va_list.*$&&context(ancestor_or_self(name(elf_call_log_callback)&&kind(function))))"}
+-config=MC3R1.R17.1,reports+={deliberate,"any_area(^.*va_list.*$&&context(ancestor_or_self(name(vprintk_common)&&kind(function))))"}
+-config=MC3R1.R17.1,macros+={hide , "^va_(arg|start|copy|end)$"}
+-doc_end
+
 #
 # Series 18.
 #
diff --git a/docs/misra/deviations.rst b/docs/misra/deviations.rst
index eb5ef2bd9d..dd254a9640 100644
--- a/docs/misra/deviations.rst
+++ b/docs/misra/deviations.rst
@@ -334,6 +334,11 @@ Deviations related to MISRA C:2012 Rules:
        improve readability.
      - Tagged as `deliberate` for ECLAIR.
 
+   * - R17.1
+     - printf()-like functions  are allowed to use the variadic features provided
+       by `stdarg.h`.
+     - Tagged as `deliberate` for ECLAIR.
+
    * - R20.4
      - The override of the keyword \"inline\" in xen/compiler.h is present so
        that section contents checks pass when the compiler chooses not to
-- 
2.34.1