[PATCH v6] automation/eclair: update configuration of D4.10

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

MISRA C Directive 4.10 states that "Precautions shall be taken in order
to prevent the contents of a header file being included more than
once".

Add a SAF tag and update the comment on top of cpufeatures.h.
Add a header inclusion guard to compile.h.
Generate header guards for hypercall-defs.h

Update ECLAIR configuration to:
- extend existing deviation to other comments explicitly saying a file
  is intended for multiple inclusion;
- extend existing deviation to other autogenerated files;
- tag the guidelines as clean.

Update deviations.rst accordingly.

Signed-off-by: Federico Serafini <federico.serafini@xxxxxxxxxxx>
Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxx>
---
Changes in v6:
- remove in-code comment and use SAF-8-safe instead
- add header guards for hypercall-defs.h

Successful pipeline:
https://gitlab.com/xen-project/people/sstabellini/xen/-/pipelines/1885561040
---

diff --git a/automation/eclair_analysis/ECLAIR/deviations.ecl 
b/automation/eclair_analysis/ECLAIR/deviations.ecl
index 9c67358d46..3b5bc87e1d 100644
--- a/automation/eclair_analysis/ECLAIR/deviations.ecl
+++ b/automation/eclair_analysis/ECLAIR/deviations.ecl
@@ -72,11 +72,14 @@ they are not instances of commented-out code."
 -config=MC3A2.D4.3,reports+={deliberate, 
"any_area(any_loc(file(arm64_bitops))&&context(name(int_clear_mask16)))"}
 -doc_end
 
--doc_begin="Files that are intended to be included more than once do not need 
to
-conform to the directive."
+-doc_begin="Files that are intended to be included more than once (and have
+a comment that says this explicitly) do not need to conform to the directive."
 -config=MC3A2.D4.10,reports+={safe, "first_area(text(^/\\* This file is 
intended to be included multiple times\\. \\*/$, begin-4))"}
--config=MC3A2.D4.10,reports+={safe, "first_area(text(^/\\* Generated file, do 
not edit! \\*/$, begin-3))"}
--config=MC3A2.D4.10,reports+={safe, 
"all_area(all_loc(file(^xen/include/generated/autoconf.h$)))"}
+-config=MC3A2.D4.10,reports+={safe, "first_area(text(^/\\* Generated file, do 
not edit! \\*/$, begin-3...begin-2))"}
+-doc_end
+
+-doc_begin="Autogenerated files that do not need to conform to the directive."
+-config=MC3A2.D4.10,reports+={safe, 
"all_area(all_loc(file(^xen/include/generated/autoconf\\.h$)))"}
 -doc_end
 
 -doc_begin="Including multiple times a .c file is safe because every function 
or data item
diff --git a/automation/eclair_analysis/ECLAIR/tagging.ecl 
b/automation/eclair_analysis/ECLAIR/tagging.ecl
index f9da5d5f4d..b95f07feb0 100644
--- a/automation/eclair_analysis/ECLAIR/tagging.ecl
+++ b/automation/eclair_analysis/ECLAIR/tagging.ecl
@@ -23,6 +23,7 @@
 "MC3A2.D1.1||
 MC3A2.D2.1||
 MC3A2.D4.1||
+MC3A2.D4.10||
 MC3A2.D4.11||
 MC3A2.D4.14||
 MC3A2.R1.1||
diff --git a/docs/misra/deviations.rst b/docs/misra/deviations.rst
index fe0b1e10a2..63caa8f4a2 100644
--- a/docs/misra/deviations.rst
+++ b/docs/misra/deviations.rst
@@ -30,6 +30,18 @@ Deviations related to MISRA C:2012 Directives:
        not to add an additional encapsulation layer.
      - Tagged as `deliberate` for ECLAIR.
 
+   * - D4.10
+     - Files that are intended to be included more than once (and have
+       a comment that says this explicitly) do not need to conform to the
+       directive.
+     - Tagged as `safe` for ECLAIR.
+
+   * - D4.10
+     - There are autogenerated files that do not need to comply to the
+       directive.
+     - Tagged as `safe` for ECLAIR. Such files are:
+        - xen/include/generated/autoconf.h
+
    * - D4.10
      - Including multiple times a .c file is safe because every function or 
data item
        it defines would in (the common case) be already defined.
diff --git a/xen/arch/x86/include/asm/cpufeatures.h 
b/xen/arch/x86/include/asm/cpufeatures.h
index 9e3ed21c02..dce0713adf 100644
--- a/xen/arch/x86/include/asm/cpufeatures.h
+++ b/xen/arch/x86/include/asm/cpufeatures.h
@@ -1,7 +1,6 @@
-/*
- * Explicitly intended for multiple inclusion.
- */
+/* This file is intended to be included multiple times. */
 
+/* SAF-8-safe */
 #include <xen/lib/x86/cpuid-autogen.h>
 
 /* Number of capability words covered by the featureset words. */
diff --git a/xen/include/xen/compile.h.in b/xen/include/xen/compile.h.in
index 3151d1e7d1..9206341ba6 100644
--- a/xen/include/xen/compile.h.in
+++ b/xen/include/xen/compile.h.in
@@ -1,3 +1,6 @@
+#ifndef XEN_COMPILE_H
+#define XEN_COMPILE_H
+
 #define XEN_COMPILE_DATE       "@@date@@"
 #define XEN_COMPILE_TIME       "@@time@@"
 #define XEN_COMPILE_BY         "@@whoami@@"
diff --git a/xen/scripts/gen_hypercall.awk b/xen/scripts/gen_hypercall.awk
index 1a7e051fde..47a18cd75e 100644
--- a/xen/scripts/gen_hypercall.awk
+++ b/xen/scripts/gen_hypercall.awk
@@ -2,6 +2,8 @@
 # the calls of the handlers inside a switch() statement.
 
 BEGIN {
+    printf("#ifndef XEN_HYPERCALL_DEFS_H\n");
+    printf("#define XEN_HYPERCALL_DEFS_H\n\n");
     printf("/* Generated file, do not edit! */\n\n");
     e = 0;
     n = 0;
@@ -311,4 +313,5 @@ END {
                 printf("[__HYPERVISOR_%s] = %d, \\\n", fn[call_fn[i]], 
n_args[call_fn[i]]);
         printf("}\n");
     }
+    printf("\n#endif /* XEN_HYPERCALL_DEFS_H */\n");
 }
diff --git a/xen/tools/process-banner.sed b/xen/tools/process-banner.sed
index 56c76558bc..4cf3f9a116 100755
--- a/xen/tools/process-banner.sed
+++ b/xen/tools/process-banner.sed
@@ -12,3 +12,8 @@ s_(.*)_"\1\\n"_
 
 # Trailing \ on all but the final line.
 $!s_$_ \\_
+
+# Append closing header guard
+$a\
+\
+#endif /* XEN_COMPILE_H */