golang/xenlight: Extend KeyedUnion to support Arrays

Generation for KeyedUnion types doesn't support Arrays.  The smbios
support will place an smbios array inside the hvm KeyedUnion, and
gentotypes doesn't generate buildable Go code.

Have KeyedUnion add an idl.Array check and issue the approriate
xenlight_golang_array_to_C and xenlight_golang_array_from_C calls when
needed.  This matches how it is done in xenlight_golang_define_to_C &
xenlight_golang_define_from_C

xenlight_golang_array_to_C and xenlight_golang_array_from_C need to be
extended to set the cvarname and govarname as approriate for the
KeyedUnion cases to match the surrounding code.

Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
Acked-by: George Dunlap <george.dunlap@citrix.com>

tools/golang/xenlight/gengotypes.py

@@ -376,6 +376,10 @@ def xenlight_golang_union_from_C(ty = None, union_name = '', struct_name = ''):
         s += 'tmp := (*C.{0})(unsafe.Pointer(&xc.{1}[0]))\n'.format(typename,union_name)
 
         for nf in f.type.fields:
+            if isinstance(nf.type, idl.Array):
+                s += xenlight_golang_array_from_C(nf,cvarname='tmp')
+                continue
+
             s += xenlight_golang_convert_from_C(nf,cvarname='tmp')
 
         s += 'return nil\n'
@@ -416,7 +420,7 @@ def xenlight_golang_union_from_C(ty = None, union_name = '', struct_name = ''):
 
     return (s,extras)
 
-def xenlight_golang_array_from_C(ty = None):
+def xenlight_golang_array_from_C(ty = None, cvarname = 'xc'):
     """
     Convert C array to Go slice using the method
     described here:
@@ -433,9 +437,9 @@ def xenlight_golang_array_from_C(ty = None):
     clenvar    = ty.type.lenvar.name
 
     s += 'x.{0} = nil\n'.format(goname)
-    s += 'if n := int(xc.{0}); n > 0 {{\n'.format(clenvar)
+    s += 'if n := int({0}.{1}); n > 0 {{\n'.format(cvarname,clenvar)
     s += '{0} := '.format(cslice)
-    s +='(*[1<<28]C.{0})(unsafe.Pointer(xc.{1}))[:n:n]\n'.format(ctypename, cname)
+    s +='(*[1<<28]C.{0})(unsafe.Pointer({1}.{2}))[:n:n]\n'.format(ctypename, cvarname, cname)
     s += 'x.{0} = make([]{1}, n)\n'.format(goname, gotypename)
     s += 'for i, v := range {0} {{\n'.format(cslice)
 
@@ -579,6 +583,11 @@ def xenlight_golang_union_to_C(ty = None, union_name = '',
 
         s += 'var {0} C.{1}\n'.format(f.name,cgotype)
         for uf in f.type.fields:
+            if isinstance(uf.type, idl.Array):
+                s += xenlight_golang_array_to_C(uf, cvarname=f.name,
+                                                govarname="tmp")
+                continue
+
             s += xenlight_golang_convert_to_C(uf,cvarname=f.name,
                                               govarname='tmp')
 
@@ -596,7 +605,7 @@ def xenlight_golang_union_to_C(ty = None, union_name = '',
 
     return s
 
-def xenlight_golang_array_to_C(ty = None):
+def xenlight_golang_array_to_C(ty = None, cvarname="xc", govarname="x"):
     s = ''
 
     gotypename = xenlight_golang_fmt_name(ty.type.elem_type.typename)
@@ -608,27 +617,27 @@ def xenlight_golang_array_to_C(ty = None):
 
     is_enum = isinstance(ty.type.elem_type,idl.Enumeration)
     if gotypename in go_builtin_types or is_enum:
-        s += 'if {0} := len(x.{1}); {2} > 0 {{\n'.format(golenvar,goname,golenvar)
-        s += 'xc.{0} = (*C.{1})(C.malloc(C.size_t({2}*{3})))\n'.format(cname,ctypename,
+        s += 'if {0} := len({1}.{2}); {3} > 0 {{\n'.format(golenvar,govarname,goname,golenvar)
+        s += '{0}.{1} = (*C.{2})(C.malloc(C.size_t({3}*{4})))\n'.format(cvarname,cname,ctypename,
                                                                    golenvar,golenvar)
-        s += 'xc.{0} = C.int({1})\n'.format(clenvar,golenvar)
-        s += 'c{0} := (*[1<<28]C.{1})(unsafe.Pointer(xc.{2}))[:{3}:{4}]\n'.format(goname,
-                                                                      ctypename,cname,
+        s += '{0}.{1} = C.int({2})\n'.format(cvarname,clenvar,golenvar)
+        s += 'c{0} := (*[1<<28]C.{1})(unsafe.Pointer({2}.{3}))[:{4}:{5}]\n'.format(goname,
+                                                                      ctypename,cvarname,cname,
                                                                       golenvar,golenvar)
-        s += 'for i,v := range x.{0} {{\n'.format(goname)
+        s += 'for i,v := range {0}.{1} {{\n'.format(govarname,goname)
         s += 'c{0}[i] = C.{1}(v)\n'.format(goname,ctypename)
         s += '}\n}\n'
 
         return s
 
-    s += 'if {0} := len(x.{1}); {2} > 0 {{\n'.format(golenvar,goname,golenvar)
-    s += 'xc.{0} = (*C.{1})(C.malloc(C.ulong({2})*C.sizeof_{3}))\n'.format(cname,ctypename,
+    s += 'if {0} := len({1}.{2}); {3} > 0 {{\n'.format(golenvar,govarname,goname,golenvar)
+    s += '{0}.{1} = (*C.{2})(C.malloc(C.ulong({3})*C.sizeof_{4}))\n'.format(cvarname,cname,ctypename,
                                                                    golenvar,ctypename)
-    s += 'xc.{0} = C.int({1})\n'.format(clenvar,golenvar)
-    s += 'c{0} := (*[1<<28]C.{1})(unsafe.Pointer(xc.{2}))[:{3}:{4}]\n'.format(goname,
-                                                                         ctypename,cname,
+    s += '{0}.{1} = C.int({2})\n'.format(cvarname,clenvar,golenvar)
+    s += 'c{0} := (*[1<<28]C.{1})(unsafe.Pointer({2}.{3}))[:{4}:{5}]\n'.format(goname,
+                                                                         ctypename,cvarname,cname,
                                                                          golenvar,golenvar)
-    s += 'for i,v := range x.{0} {{\n'.format(goname)
+    s += 'for i,v := range {0}.{1} {{\n'.format(govarname,goname)
     s += 'if err := v.toC(&c{0}[i]); err != nil {{\n'.format(goname)
     s += 'return fmt.Errorf("converting field {0}: %v", err)\n'.format(goname)
     s += '}\n}\n}\n'