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>

6 files changed, 144 insertions, 73 deletions

diff --git a/tools/libxl/gentypes.py b/tools/libxl/gentypes.py
index 20d403079a..099a3919f2 100644
--- a/tools/libxl/gentypes.py
+++ b/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)
 
diff --git a/tools/libxl/idl.txt b/tools/libxl/idl.txt
index c691051393..9048828e77 100644
--- a/tools/libxl/idl.txt
+++ b/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
diff --git a/tools/libxl/libxl.h b/tools/libxl/libxl.h
index 464527411c..f4f7faa2c2 100644
--- a/tools/libxl/libxl.h
+++ b/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);
diff --git a/tools/libxl/libxl.idl b/tools/libxl/libxl.idl
index 8186c2a400..1ccddfc1ba 100644
--- a/tools/libxl/libxl.idl
+++ b/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)
@@ -24,6 +17,73 @@ 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
 #
 libxl_dominfo = Struct("dominfo",[
diff --git a/tools/libxl/libxltypes.py b/tools/libxl/libxltypes.py
index 9c9e6427e7..a00711fe1e 100644
--- a/tools/libxl/libxltypes.py
+++ b/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)
diff --git a/tools/libxl/xl_cmdimpl.c b/tools/libxl/xl_cmdimpl.c
index f92b6e2777..48d89f97e3 100644
--- a/tools/libxl/xl_cmdimpl.c
+++ b/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;