tools: libxl: add an Enumeration type to the IDL

The IDL requires a specific value for each enumerate, this make it
much easier to avoid (or at least track) ABI changes since they must
now be explicit.

I believe I have used the same values as would have been chosen
previoulsy but have not confirmed.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Ian Jackson <ian.jackson.citrix.com>
Committed-by: Ian Jackson <ian.jackson.citrix.com>

tools/libxl/gentypes.py

@@ -34,7 +34,28 @@ def libxl_C_instance_of(ty, instancename):
 
 def libxl_C_type_define(ty, indent = ""):
     s = ""
-    if isinstance(ty, libxltypes.Aggregate):
+
+    if isinstance(ty, libxltypes.Enumeration):
+        if ty.comment is not None:
+            s += format_comment(0, ty.comment)
+        
+        if ty.typename is None:
+            s += "enum {\n"
+        else:
+            s += "typedef enum %s {\n" % ty.typename
+
+        for v in ty.values:
+            if v.comment is not None:
+                s += format_comment(4, v.comment)
+            x = "%s = %d" % (v.name, v.value)
+            x = x.replace("\n", "\n    ")
+            s += "    " + x + ",\n"
+        if ty.typename is None:
+            s += "}"
+        else:
+            s += "} %s" % ty.typename
+
+    elif isinstance(ty, libxltypes.Aggregate):
         if ty.comment is not None:
             s += format_comment(0, ty.comment)
 

tools/libxl/idl.txt

@@ -82,6 +82,30 @@ libxltype.Reference
 Complex type-Classes
 --------------------
 
+libxltype.Enumeration
+
+  A class representing an enumeration (named integer values).
+
+  The values are available in the list Enumeration.values. Each
+  element in the list is of type libxltype.EnumerationValue.
+
+  Each EnumerationValue has the following properties:
+
+    EnumerationValue.enum	Reference to containing Enumeration
+    EnumerationValue.name       The C name of this value, including
+                                    the namespace and typename of the
+                                    containing Enumeration (e.g.
+                                    "LIBXL_FOOENUM_VALUE")
+    EnumerationValue.rawname    The C name of this value, excluding
+                                    the namespace but including the
+                                    typename of the containing
+                                    Enumeration (e.g. "FOOENUM_VALUE")
+    EnumerationValue.valuename	The name of this value, excluding the
+				    name of the containing Enumeration
+				    and any namespace (e.g. "VALUE")
+    EnumerationValue.value	The integer value associated with this name.
+    EnumerationValue.comment	A free text comment which describes the member.
+
 libxltype.Aggregate
 
  Base class for type-Classes which contain a number of other types

tools/libxl/libxl.h

@@ -161,49 +161,6 @@ typedef struct {
 #define LIBXL_CPUARRAY_INVALID_ENTRY  ~0
 void libxl_cpuarray_destroy(libxl_cpuarray *array);
 
-typedef enum {
-    LIBXL_DOMAIN_TYPE_FV = 1,
-    LIBXL_DOMAIN_TYPE_PV,
-} libxl_domain_type;
-
-typedef enum libxl_device_model_version {
-    /* Historical qemu-xen device model (qemu-dm) */
-    LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN_TRADITIONAL = 1,
-    /* Upstream based qemu-xen device model */
-    LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN = 2,
-} libxl_device_model_version;
-
-typedef enum {
-    LIBXL_CONSOLE_TYPE_SERIAL = 1,
-    LIBXL_CONSOLE_TYPE_PV,
-} libxl_console_type;
-
-typedef enum {
-    LIBXL_CONSOLE_BACKEND_XENCONSOLED,
-    LIBXL_CONSOLE_BACKEND_IOEMU,
-} libxl_console_backend;
-
-typedef enum {
-    LIBXL_DISK_FORMAT_UNKNOWN = 0,
-    LIBXL_DISK_FORMAT_QCOW,
-    LIBXL_DISK_FORMAT_QCOW2,
-    LIBXL_DISK_FORMAT_VHD,
-    LIBXL_DISK_FORMAT_RAW,
-    LIBXL_DISK_FORMAT_EMPTY,
-} libxl_disk_format;
-
-typedef enum {
-    LIBXL_DISK_BACKEND_UNKNOWN = 0,
-    LIBXL_DISK_BACKEND_PHY,
-    LIBXL_DISK_BACKEND_TAP,
-    LIBXL_DISK_BACKEND_QDISK,
-} libxl_disk_backend;
-
-typedef enum {
-    LIBXL_NIC_TYPE_IOEMU = 1,
-    LIBXL_NIC_TYPE_VIF,
-} libxl_nic_type;
-
 typedef struct {
     /*
      * Path is always set if the file reference is valid. However if
@@ -252,18 +209,6 @@ enum {
 
 #define LIBXL_VERSION 0
 
-typedef enum libxl_action_on_shutdown {
-    LIBXL_ACTION_ON_SHUTDOWN_DESTROY,
-
-    LIBXL_ACTION_ON_SHUTDOWN_RESTART,
-    LIBXL_ACTION_ON_SHUTDOWN_RESTART_RENAME,
-
-    LIBXL_ACTION_ON_SHUTDOWN_PRESERVE,
-
-    LIBXL_ACTION_ON_SHUTDOWN_COREDUMP_DESTROY,
-    LIBXL_ACTION_ON_SHUTDOWN_COREDUMP_RESTART,
-} libxl_action_on_shutdown;
-
 typedef struct {
     libxl_domain_create_info c_info;
     libxl_domain_build_info b_info;
@@ -327,11 +272,6 @@ int libxl_run_bootloader(libxl_ctx *ctx,
 
 /* events handling */
 
-typedef enum {
-    LIBXL_EVENT_TYPE_DOMAIN_DEATH,
-    LIBXL_EVENT_TYPE_DISK_EJECT,
-} libxl_event_type;
-
 typedef struct {
     /* event type */
     libxl_event_type type;
@@ -494,11 +434,6 @@ int libxl_userdata_retrieve(libxl_ctx *ctx, uint32_t domid,
    * On error return, *data_r and *datalen_r are undefined.
    */
 
-typedef enum {
-    LIBXL_BUTTON_POWER,
-    LIBXL_BUTTON_SLEEP
-} libxl_button;
-
 int libxl_button_press(libxl_ctx *ctx, uint32_t domid, libxl_button button);
 
 int libxl_get_physinfo(libxl_ctx *ctx, libxl_physinfo *physinfo);

tools/libxl/libxl.idl

@@ -8,13 +8,6 @@ libxl_uuid = Builtin("uuid")
 libxl_mac = Builtin("mac")
 libxl_cpumap = Builtin("cpumap", destructor_fn="libxl_cpumap_destroy", passby=PASS_BY_REFERENCE)
 libxl_cpuarray = Builtin("cpuarray", destructor_fn="libxl_cpuarray_destroy", passby=PASS_BY_REFERENCE)
-libxl_domain_type = Number("domain_type", namespace="libxl_")
-libxl_device_model_version = Number("device_model_version", namespace="libxl_")
-libxl_console_backend = Number("console_backend", namespace="libxl_")
-libxl_console_type = Number("console_type", namespace="libxl_")
-libxl_disk_format = Number("disk_format", namespace="libxl_")
-libxl_disk_backend = Number("disk_backend", namespace="libxl_")
-libxl_nic_type = Number("nic_type", namespace="libxl_")
 libxl_cpuid_policy_list = Builtin("cpuid_policy_list", destructor_fn="libxl_cpuid_destroy", passby=PASS_BY_REFERENCE)
 
 libxl_string_list = Builtin("string_list", destructor_fn="libxl_string_list_destroy", passby=PASS_BY_REFERENCE)
@@ -23,6 +16,73 @@ libxl_file_reference = Builtin("file_reference", destructor_fn="libxl_file_refer
 
 libxl_hwcap = Builtin("hwcap")
 
+#
+# Constants / Enumerations
+#
+
+libxl_domain_type = Enumeration("domain_type", [
+    (1, "FV"),
+    (2, "PV"),
+    ])
+
+libxl_device_model_version = Enumeration("device_model_version", [
+    (1, "QEMU_XEN_TRADITIONAL", "Historical qemu-xen device model (qemu-dm)"),
+    (2, "QEMU_XEN", "Upstream based qemu-xen device model"),
+    ])
+
+libxl_console_type = Enumeration("console_type", [
+    (1, "SERIAL"),
+    (2, "PV"),
+    ])
+
+libxl_console_backend = Enumeration("console_backend", [
+    (1, "XENCONSOLED"),
+    (2, "IOEMU"),
+    ])
+
+libxl_disk_format = Enumeration("disk_format", [
+    (0, "UNKNOWN"),
+    (1, "QCOW"),
+    (2, "QCOW2"),
+    (3, "VHD"),
+    (4, "RAW"),
+    (5, "EMPTY"),
+    ])
+
+libxl_disk_backend = Enumeration("disk_backend", [
+    (0, "UNKNOWN"),
+    (1, "PHY"),
+    (2, "TAP"),
+    (3, "QDISK"),
+    ])
+
+libxl_nic_type = Enumeration("nic_type", [
+    (1, "IOEMU"),
+    (2, "VIF"),
+    ])
+
+libxl_action_on_shutdown = Enumeration("action_on_shutdown", [
+    (1, "DESTROY"),
+
+    (2, "RESTART"),
+    (3, "RESTART_RENAME"),
+
+    (4, "PRESERVE"),
+
+    (5, "COREDUMP_DESTROY"),
+    (6, "COREDUMP_RESTART"),
+    ])
+
+libxl_event_type = Enumeration("event_type", [
+    (1, "DOMAIN_DEATH"),
+    (2, "DISK_EJECT"),
+    ])
+
+libxl_button = Enumeration("button", [
+    (1, "POWER"),
+    (2, "SLEEP"),
+    ])
+
 #
 # Complex libxl types
 #

tools/libxl/libxltypes.py

@@ -52,6 +52,35 @@ class UInt(Number):
 
         self.width = w
 
+class EnumerationValue(object):
+    def __init__(self, enum, value, name, **kwargs):
+        self.enum = enum
+
+        self.valuename = str.upper(name)
+        self.rawname = str.upper(enum.rawname) + "_" + self.valuename
+        self.name = str.upper(enum.namespace) + self.rawname
+        self.value = value
+        self.comment = kwargs.setdefault("comment", None)
+        
+class Enumeration(Type):
+    def __init__(self, typename, values, **kwargs):
+        kwargs.setdefault('destructor_fn', None)
+        Type.__init__(self, typename, **kwargs)
+
+        self.values = []
+        for v in values:
+            # (value, name[, comment=None])
+            if len(v) == 2:
+                (num,name) = v
+                comment = None
+            elif len(v) == 3:
+                num,name,comment = v
+            else:
+                raise ""
+            self.values.append(EnumerationValue(self, num, name,
+                                                comment=comment,
+                                                typename=self.rawname))
+        
 class BitField(Type):
     def __init__(self, ty, w, **kwargs):
         kwargs.setdefault('namespace', None)

tools/libxl/xl_cmdimpl.c

@@ -451,6 +451,8 @@ static int parse_action_on_shutdown(const char *buf, libxl_action_on_shutdown *a
     for (i = 0; i < sizeof(action_on_shutdown_names) / sizeof(action_on_shutdown_names[0]); i++) {
         n = action_on_shutdown_names[i];
 
+        if (!n) continue;
+
         if (strcmp(buf, n) == 0) {
             *a = i;
             return 1;

tools/python/genwrap.py

@@ -9,6 +9,8 @@ import libxltypes
 def py_type(ty):
     if ty == libxltypes.bool or isinstance(ty, libxltypes.BitField) and ty.width == 1:
         return TYPE_BOOL
+    if isinstance(ty, libxltypes.Enumeration):
+        return TYPE_UINT
     if isinstance(ty, libxltypes.Number):
         if ty.signed:
             return TYPE_INT
@@ -34,15 +36,16 @@ def fsanitize(name):
 
 def py_decls(ty):
     l = []
-    l.append('_hidden Py_%s *Py%s_New(void);\n'%(ty.rawname, ty.rawname))
-    l.append('_hidden int Py%s_Check(PyObject *self);\n'%ty.rawname)
-    for f in ty.fields:
-        if py_type(f.type) is not None:
-            continue
-        l.append('_hidden PyObject *attrib__%s_get(%s *%s);'%(\
-                 fsanitize(f.type.typename), f.type.typename, f.name))
-        l.append('_hidden int attrib__%s_set(PyObject *v, %s *%s);'%(\
-                 fsanitize(f.type.typename), f.type.typename, f.name))
+    if isinstance(ty, libxltypes.Aggregate):
+        l.append('_hidden Py_%s *Py%s_New(void);\n'%(ty.rawname, ty.rawname))
+        l.append('_hidden int Py%s_Check(PyObject *self);\n'%ty.rawname)
+        for f in ty.fields:
+            if py_type(f.type) is not None:
+                continue
+            l.append('_hidden PyObject *attrib__%s_get(%s *%s);'%(\
+                fsanitize(f.type.typename), f.type.typename, f.name))
+            l.append('_hidden int attrib__%s_set(PyObject *v, %s *%s);'%(\
+                fsanitize(f.type.typename), f.type.typename, f.name))
     return '\n'.join(l) + "\n"
 
 def py_attrib_get(ty, f):
@@ -189,16 +192,23 @@ def py_initfuncs(types):
     l.append('void genwrap__init(PyObject *m)')
     l.append('{')
     for ty in types:
-        l.append('    if (PyType_Ready(&Py%s_Type) >= 0) {'%ty.rawname)
-        l.append('        Py_INCREF(&Py%s_Type);'%ty.rawname)
-        l.append('        PyModule_AddObject(m, "%s", (PyObject *)&Py%s_Type);'%(ty.rawname, ty.rawname))
-        l.append('    }')
+        if isinstance(ty, libxltypes.Enumeration):
+            for v in ty.values:
+                l.append('    PyModule_AddIntConstant(m, "%s", %s);' % (v.rawname, v.name))
+        elif isinstance(ty, libxltypes.Aggregate):
+            l.append('    if (PyType_Ready(&Py%s_Type) >= 0) {'%ty.rawname)
+            l.append('        Py_INCREF(&Py%s_Type);'%ty.rawname)
+            l.append('        PyModule_AddObject(m, "%s", (PyObject *)&Py%s_Type);'%(ty.rawname, ty.rawname))
+            l.append('    }')
+        else:
+            raise NotImplementedError("unknown type %s (%s)" % (ty.typename, type(ty)))        
+
     l.append('}')
     return '\n'.join(l) + "\n\n"
 
 def tree_frob(types):
     ret = types[:]
-    for ty in ret:
+    for ty in [ty for ty in ret if isinstance(ty, libxltypes.Aggregate)]:
         ty.fields = filter(lambda f:f.name is not None and f.type.typename is not None, ty.fields)
     return ret
 
@@ -249,8 +259,8 @@ _hidden PyObject *genwrap__ll_get(long long val);
 _hidden int genwrap__ll_set(PyObject *v, long long *val, long long mask);
 
 """ % " ".join(sys.argv))
-    for ty in types:
-        f.write('/* Internal APU for %s wrapper */\n'%ty.typename)
+    for ty in [ty for ty in types if isinstance(ty, libxltypes.Aggregate)]:
+        f.write('/* Internal API for %s wrapper */\n'%ty.typename)
         f.write(py_wrapstruct(ty))
         f.write(py_decls(ty))
         f.write('\n')
@@ -276,10 +286,11 @@ _hidden int genwrap__ll_set(PyObject *v, long long *val, long long mask);
 
 """ % tuple((' '.join(sys.argv),) + (os.path.split(decls)[-1:]),))
     for ty in types:
-        f.write('/* Attribute get/set functions for %s */\n'%ty.typename)
-        for a in ty.fields:
-            f.write(py_attrib_get(ty,a))
-            f.write(py_attrib_set(ty,a))
-        f.write(py_object_def(ty))
+        if isinstance(ty, libxltypes.Aggregate):
+            f.write('/* Attribute get/set functions for %s */\n'%ty.typename)
+            for a in ty.fields:
+                f.write(py_attrib_get(ty,a))
+                f.write(py_attrib_set(ty,a))
+            f.write(py_object_def(ty))
     f.write(py_initfuncs(types))
     f.close()

tools/python/xen/lowlevel/xl/xl.c

@@ -769,35 +769,6 @@ PyMODINIT_FUNC initxl(void)
     _INT_CONST(m, SHUTDOWN_crash);
     _INT_CONST(m, SHUTDOWN_watchdog);
 
-    _INT_CONST_LIBXL(m, DOMAIN_TYPE_FV);
-    _INT_CONST_LIBXL(m, DOMAIN_TYPE_PV);
-
-    _INT_CONST_LIBXL(m, CONSOLE_TYPE_SERIAL);
-    _INT_CONST_LIBXL(m, CONSOLE_TYPE_PV);
-
-    _INT_CONST_LIBXL(m, CONSOLE_BACKEND_XENCONSOLED);
-    _INT_CONST_LIBXL(m, CONSOLE_BACKEND_IOEMU);
-
-    _INT_CONST_LIBXL(m, DISK_FORMAT_UNKNOWN);
-    _INT_CONST_LIBXL(m, DISK_FORMAT_QCOW);
-    _INT_CONST_LIBXL(m, DISK_FORMAT_QCOW2);
-    _INT_CONST_LIBXL(m, DISK_FORMAT_VHD);
-    _INT_CONST_LIBXL(m, DISK_FORMAT_RAW);
-    _INT_CONST_LIBXL(m, DISK_FORMAT_EMPTY);
-
-    _INT_CONST_LIBXL(m, DISK_BACKEND_UNKNOWN);
-    _INT_CONST_LIBXL(m, DISK_BACKEND_PHY);
-    _INT_CONST_LIBXL(m, DISK_BACKEND_TAP);
-    _INT_CONST_LIBXL(m, DISK_BACKEND_QDISK);
-
-    _INT_CONST_LIBXL(m, NIC_TYPE_IOEMU);
-    _INT_CONST_LIBXL(m, NIC_TYPE_VIF);
-
-    _INT_CONST_LIBXL(m, EVENT_TYPE_DOMAIN_DEATH);
-    _INT_CONST_LIBXL(m, EVENT_TYPE_DISK_EJECT);
-
-    _INT_CONST_LIBXL(m, BUTTON_POWER);
-    _INT_CONST_LIBXL(m, BUTTON_SLEEP);
     genwrap__init(m);
 }