qapi: Change data type of the FOO_lookup generated for enum FOO

Currently, a FOO_lookup is an array of strings terminated by a NULL
sentinel.

A future patch will generate enums with "holes".  NULL-termination
will cease to work then.

To prepare for that, store the length in the FOO_lookup by wrapping it
in a struct and adding a member for the length.

The sentinel will be dropped next.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20170822132255.23945-13-marcandre.lureau@redhat.com>
[Basically redone]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1503564371-26090-16-git-send-email-armbru@redhat.com>
[Rebased]

1 files changed, 13 insertions, 11 deletions

diff --git a/qapi/qapi-visit-core.c b/qapi/qapi-visit-core.c
index 30dc85b6f3..3dcb968867 100644
--- a/qapi/qapi-visit-core.c
+++ b/qapi/qapi-visit-core.c
@@ -333,24 +333,26 @@ void visit_type_null(Visitor *v, const char *name, QNull **obj,
 }
 
 static void output_type_enum(Visitor *v, const char *name, int *obj,
-                             const char *const strings[], Error **errp)
+                             const QEnumLookup *lookup, Error **errp)
 {
-    int i = 0;
     int value = *obj;
     char *enum_str;
 
-    while (strings[i++] != NULL);
-    if (value < 0 || value >= i - 1) {
+    /*
+     * TODO why is this an error, not an assertion?  If assertion:
+     * delete, and rely on qapi_enum_lookup()
+     */
+    if (value < 0 || value >= lookup->size) {
         error_setg(errp, QERR_INVALID_PARAMETER, name ? name : "null");
         return;
     }
 
-    enum_str = (char *)qapi_enum_lookup(strings, value);
+    enum_str = (char *)qapi_enum_lookup(lookup, value);
     visit_type_str(v, name, &enum_str, errp);
 }
 
 static void input_type_enum(Visitor *v, const char *name, int *obj,
-                            const char *const strings[], Error **errp)
+                            const QEnumLookup *lookup, Error **errp)
 {
     Error *local_err = NULL;
     int64_t value;
@@ -362,7 +364,7 @@ static void input_type_enum(Visitor *v, const char *name, int *obj,
         return;
     }
 
-    value = qapi_enum_parse(strings, enum_str, -1, NULL);
+    value = qapi_enum_parse(lookup, enum_str, -1, NULL);
     if (value < 0) {
         error_setg(errp, QERR_INVALID_PARAMETER, enum_str);
         g_free(enum_str);
@@ -374,16 +376,16 @@ static void input_type_enum(Visitor *v, const char *name, int *obj,
 }
 
 void visit_type_enum(Visitor *v, const char *name, int *obj,
-                     const char *const strings[], Error **errp)
+                     const QEnumLookup *lookup, Error **errp)
 {
-    assert(obj && strings);
+    assert(obj && lookup);
     trace_visit_type_enum(v, name, obj);
     switch (v->type) {
     case VISITOR_INPUT:
-        input_type_enum(v, name, obj, strings, errp);
+        input_type_enum(v, name, obj, lookup, errp);
         break;
     case VISITOR_OUTPUT:
-        output_type_enum(v, name, obj, strings, errp);
+        output_type_enum(v, name, obj, lookup, errp);
         break;
     case VISITOR_CLONE:
         /* nothing further to do, scalar value was already copied by