qobject: Eliminate qlist_iter(), use QLIST_FOREACH_ENTRY() instead

qlist_iter() has just three uses outside tests/.  Replace by
QLIST_FOREACH_ENTRY() for more concise code and less type punning.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200415083048.14339-4-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>

include/qapi/qmp/qlist.h

@@ -47,8 +47,6 @@ static inline QObject *qlist_entry_obj(const QListEntry *entry)
 QList *qlist_new(void);
 QList *qlist_copy(QList *src);
 void qlist_append_obj(QList *qlist, QObject *obj);
-void qlist_iter(const QList *qlist,
-                void (*iter)(QObject *obj, void *opaque), void *opaque);
 QObject *qlist_pop(QList *qlist);
 QObject *qlist_peek(QList *qlist);
 int qlist_empty(const QList *qlist);

qobject/qjson.c

@@ -191,20 +191,6 @@ static void to_json_dict_iter(const char *key, QObject *obj, void *opaque)
     s->count++;
 }
 
-static void to_json_list_iter(QObject *obj, void *opaque)
-{
-    ToJsonIterState *s = opaque;
-
-    if (s->count) {
-        qstring_append(s->str, s->pretty ? "," : ", ");
-    }
-
-    json_pretty_newline(s->str, s->pretty, s->indent);
-
-    to_json(obj, s->str, s->pretty, s->indent);
-    s->count++;
-}
-
 static void to_json(const QObject *obj, QString *str, int pretty, int indent)
 {
     switch (qobject_type(obj)) {
@@ -289,15 +275,20 @@ static void to_json(const QObject *obj, QString *str, int pretty, int indent)
         break;
     }
     case QTYPE_QLIST: {
-        ToJsonIterState s;
         QList *val = qobject_to(QList, obj);
+        const char *comma = pretty ? "," : ", ";
+        const char *sep = "";
+        QListEntry *entry;
 
-        s.count = 0;
-        s.str = str;
-        s.indent = indent + 1;
-        s.pretty = pretty;
         qstring_append(str, "[");
-        qlist_iter(val, (void *)to_json_list_iter, &s);
+
+        QLIST_FOREACH_ENTRY(val, entry) {
+            qstring_append(str, sep);
+            json_pretty_newline(str, pretty, indent + 1);
+            to_json(qlist_entry_obj(entry), str, pretty, indent + 1);
+            sep = comma;
+        }
+
         json_pretty_newline(str, pretty, indent);
         qstring_append(str, "]");
         break;

qobject/qlist.c

@@ -34,20 +34,17 @@ QList *qlist_new(void)
     return qlist;
 }
 
-static void qlist_copy_elem(QObject *obj, void *opaque)
-{
-    QList *dst = opaque;
-
-    qobject_ref(obj);
-    qlist_append_obj(dst, obj);
-}
-
 QList *qlist_copy(QList *src)
 {
     QList *dst = qlist_new();
+    QListEntry *entry;
+    QObject *elt;
 
-    qlist_iter(src, qlist_copy_elem, dst);
-
+    QLIST_FOREACH_ENTRY(src, entry) {
+        elt = qlist_entry_obj(entry);
+        qobject_ref(elt);
+        qlist_append_obj(dst, elt);
+    }
     return dst;
 }
 
@@ -86,21 +83,6 @@ void qlist_append_null(QList *qlist)
     qlist_append(qlist, qnull());
 }
 
-/**
- * qlist_iter(): Iterate over all the list's stored values.
- *
- * This function allows the user to provide an iterator, which will be
- * called for each stored value in the list.
- */
-void qlist_iter(const QList *qlist,
-                void (*iter)(QObject *obj, void *opaque), void *opaque)
-{
-    QListEntry *entry;
-
-    QTAILQ_FOREACH(entry, &qlist->head, next)
-        iter(entry->value, opaque);
-}
-
 QObject *qlist_pop(QList *qlist)
 {
     QListEntry *entry;
@@ -137,16 +119,14 @@ int qlist_empty(const QList *qlist)
     return QTAILQ_EMPTY(&qlist->head);
 }
 
-static void qlist_size_iter(QObject *obj, void *opaque)
-{
-    size_t *count = opaque;
-    (*count)++;
-}
-
 size_t qlist_size(const QList *qlist)
 {
     size_t count = 0;
-    qlist_iter(qlist, qlist_size_iter, &count);
+    QListEntry *entry;
+
+    QLIST_FOREACH_ENTRY(qlist, entry) {
+        count++;
+    }
     return count;
 }
 

tests/check-qlist.c

@@ -61,40 +61,31 @@ static void qobject_to_qlist_test(void)
     qobject_unref(qlist);
 }
 
-static int iter_called;
-static const int iter_max = 42;
-
-static void iter_func(QObject *obj, void *opaque)
-{
-    QNum *qi;
-    int64_t val;
-
-    g_assert(opaque == NULL);
-
-    qi = qobject_to(QNum, obj);
-    g_assert(qi != NULL);
-
-    g_assert(qnum_get_try_int(qi, &val));
-    g_assert_cmpint(val, >=, 0);
-    g_assert_cmpint(val, <=, iter_max);
-
-    iter_called++;
-}
-
 static void qlist_iter_test(void)
 {
+    const int iter_max = 42;
     int i;
     QList *qlist;
+    QListEntry *entry;
+    QNum *qi;
+    int64_t val;
 
     qlist = qlist_new();
 
     for (i = 0; i < iter_max; i++)
         qlist_append_int(qlist, i);
 
-    iter_called = 0;
-    qlist_iter(qlist, iter_func, NULL);
+    i = 0;
+    QLIST_FOREACH_ENTRY(qlist, entry) {
+        qi = qobject_to(QNum, qlist_entry_obj(entry));
+        g_assert(qi != NULL);
 
-    g_assert(iter_called == iter_max);
+        g_assert(qnum_get_try_int(qi, &val));
+        g_assert_cmpint(val, ==, i);
+        i++;
+    }
+
+    g_assert(i == iter_max);
 
     qobject_unref(qlist);
 }