[PATCH v6 4/5] tools: foreign: add checks for compatible architectures

[Ian Campbell <ian.campbell@citrix.com>]

That is architectures whose struct layout must be identical. Use this for arm32
and arm64.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Cc: Jan Beulich <JBeulich@suse.com>
Cc: Keir (Xen.org) <keir@xen.org>
Cc: Tim Deegan <tim@xen.org>
Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
---
 tools/include/xen-foreign/mkchecker.py |   21 +++++++++++++++++++--
 tools/include/xen-foreign/structs.py   |    5 +++++
 2 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/tools/include/xen-foreign/mkchecker.py b/tools/include/xen-foreign/mkchecker.py
index 66c17b1..fdad869 100644
--- a/tools/include/xen-foreign/mkchecker.py
+++ b/tools/include/xen-foreign/mkchecker.py
@@ -1,7 +1,7 @@
 #!/usr/bin/python
 
 import sys;
-from structs import structs;
+from structs import structs, compat_arches;
 
 # command line arguments
 outfile = sys.argv[1];
@@ -37,10 +37,27 @@ for struct in structs:
     f.write('\tprintf("%%-25s |", "%s");\n' % struct);
     for a in archs:
         s = struct + "_" + a;
+        if compat_arches.has_key(a):
+            compat = compat_arches[a]
+            c = struct + "_" + compat;
+        else:
+            compat = None
         f.write('#ifdef %s_has_no_%s\n' % (a, struct));
-        f.write('\tprintf("%8s", "-");\n');
+        f.write('\tprintf("%8s",\n');
+        if compat:
+            f.write('# ifndef %s_has_no_%s\n' % (compat, struct));
+            f.write('\t\t"!"\n');
+            f.write('# else\n')
+            f.write('\t\t"-"\n');
+            f.write('# endif\n')
+        else:
+            f.write('\t\t"-"\n');
+        f.write('\t);\n')
         f.write("#else\n");
         f.write('\tprintf("%%8zd", sizeof(struct %s));\n' % s);
+        if compat:
+            f.write('\tif (sizeof(struct %s) != sizeof(struct %s))\n' % (s, c))
+            f.write('\t\tprintf("!");\n')
         f.write("#endif\n");
 
     f.write('\tprintf("\\n");\n\n');
diff --git a/tools/include/xen-foreign/structs.py b/tools/include/xen-foreign/structs.py
index 476eb85..3d9f2fe 100644
--- a/tools/include/xen-foreign/structs.py
+++ b/tools/include/xen-foreign/structs.py
@@ -58,3 +58,8 @@ defines = [ "__arm__",
             "XEN_LEGACY_MAX_VCPUS",
             "MAX_GUEST_CMDLINE" ];
 
+# Architectures which must be compatible, i.e. identical
+compat_arches = {
+    'arm32': 'arm64',
+    'arm64': 'arm32',
+}
-- 
1.7.2.5