qapi: De-duplicate enum code generation

Duplicated in commit 21cd70d.  Yes, we can't import qapi-types, but
that's no excuse.  Move the helpers from qapi-types.py to qapi.py, and
replace the duplicates in qapi-event.py.

The generated event enumeration type's lookup table becomes
const-correct (see commit 2e4450f), and uses explicit indexes instead
of relying on order (see commit 912ae9c).

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1442401589-24189-10-git-send-email-armbru@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>

1 files changed, 55 insertions, 0 deletions

diff --git a/scripts/qapi.py b/scripts/qapi.py
index db5bc8533f..ba32aace99 100644
--- a/scripts/qapi.py
+++ b/scripts/qapi.py
@@ -1498,6 +1498,61 @@ def guardend(name):
 ''',
                  name=guardname(name))
 
+def generate_enum_lookup(name, values, prefix=None):
+    ret = mcgen('''
+
+const char *const %(name)s_lookup[] = {
+''',
+                name=c_name(name))
+    for value in values:
+        index = c_enum_const(name, value, prefix)
+        ret += mcgen('''
+    [%(index)s] = "%(value)s",
+''',
+                     index = index, value = value)
+
+    max_index = c_enum_const(name, 'MAX', prefix)
+    ret += mcgen('''
+    [%(max_index)s] = NULL,
+};
+''',
+        max_index=max_index)
+    return ret
+
+def generate_enum(name, values, prefix=None):
+    name = c_name(name)
+    lookup_decl = mcgen('''
+
+extern const char *const %(name)s_lookup[];
+''',
+                name=name)
+
+    enum_decl = mcgen('''
+
+typedef enum %(name)s {
+''',
+                name=name)
+
+    # append automatically generated _MAX value
+    enum_values = values + [ 'MAX' ]
+
+    i = 0
+    for value in enum_values:
+        enum_full_value = c_enum_const(name, value, prefix)
+        enum_decl += mcgen('''
+    %(enum_full_value)s = %(i)d,
+''',
+                     enum_full_value = enum_full_value,
+                     i=i)
+        i += 1
+
+    enum_decl += mcgen('''
+} %(name)s;
+''',
+                 name=name)
+
+    return enum_decl + lookup_decl
+
 #
 # Common command line parsing
 #