[PATCH] x86/gen-cpuid: avoid violations of Misra rule 1.3

[Jan Beulich <jbeulich@xxxxxxxx>]

Structures or unions without any named members aren't liked by Misra
(nor the C standard). Avoid emitting such for leaves without any known
bits.

At this occasion also add the script to the X86 section in ./MAINTAINERS.

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>

--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -601,6 +601,7 @@ F:  xen/arch/x86/
 F:     xen/include/public/arch-x86/
 F:     xen/include/xen/lib/x86
 F:     xen/lib/x86
+F:     xen/tools/gen-cpuid.py
 F:     tools/firmware/hvmloader/
 F:     tools/firmware/rombios/
 F:     tools/firmware/vgabios/
--- a/xen/tools/gen-cpuid.py
+++ b/xen/tools/gen-cpuid.py
@@ -367,6 +367,7 @@ def crunch_numbers(state):
     for word in range(state.nr_entries):
 
         names = []
+        empty = 1
         for bit in range(32):
 
             name = state.names.get(word * 32 + bit, "")
@@ -380,9 +381,15 @@ def crunch_numbers(state):
             if name in ("APIC", "OSXSAVE", "OSPKE"):
                 name = ""
 
+            if name:
+                empty = 0
+
             names.append(name.lower())
 
-        state.bitfields.append("bool " + ":1, ".join(names) + ":1")
+        if empty:
+            state.bitfields.append("unsigned int empty_" + str(word) + ":32")
+        else:
+            state.bitfields.append("bool " + ":1, ".join(names) + ":1")
 
 
 def write_results(state):