qapi: Make visitor functions taking Error ** return bool, not void

See recent commit "error: Document Error API usage rules" for
rationale.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200707160613.848843-18-armbru@redhat.com>
diff --git a/qapi/opts-visitor.c b/qapi/opts-visitor.c
index 5fe0276..7781c23 100644
--- a/qapi/opts-visitor.c
+++ b/qapi/opts-visitor.c
@@ -133,7 +133,7 @@
 }
 
 
-static void
+static bool
 opts_start_struct(Visitor *v, const char *name, void **obj,
                   size_t size, Error **errp)
 {
@@ -144,7 +144,7 @@
         *obj = g_malloc0(size);
     }
     if (ov->depth++ > 0) {
-        return;
+        return true;
     }
 
     ov->unprocessed_opts = g_hash_table_new_full(&g_str_hash, &g_str_equal,
@@ -163,10 +163,11 @@
         ov->fake_id_opt->str = g_strdup(ov->opts_root->id);
         opts_visitor_insert(ov->unprocessed_opts, ov->fake_id_opt);
     }
+    return true;
 }
 
 
-static void
+static bool
 opts_check_struct(Visitor *v, Error **errp)
 {
     OptsVisitor *ov = to_ov(v);
@@ -174,7 +175,7 @@
     GQueue *any;
 
     if (ov->depth > 1) {
-        return;
+        return true;
     }
 
     /* we should have processed all (distinct) QemuOpt instances */
@@ -184,7 +185,9 @@
 
         first = g_queue_peek_head(any);
         error_setg(errp, QERR_INVALID_PARAMETER, first->name);
+        return false;
     }
+    return true;
 }
 
 
@@ -221,7 +224,7 @@
 }
 
 
-static void
+static bool
 opts_start_list(Visitor *v, const char *name, GenericList **list, size_t size,
                 Error **errp)
 {
@@ -232,12 +235,13 @@
     /* we don't support visits without a list */
     assert(list);
     ov->repeated_opts = lookup_distinct(ov, name, errp);
-    if (ov->repeated_opts) {
-        ov->list_mode = LM_IN_PROGRESS;
-        *list = g_malloc0(size);
-    } else {
+    if (!ov->repeated_opts) {
         *list = NULL;
+        return false;
     }
+    ov->list_mode = LM_IN_PROGRESS;
+    *list = g_malloc0(size);
+    return true;
 }
 
 
@@ -285,13 +289,14 @@
 }
 
 
-static void
+static bool
 opts_check_list(Visitor *v, Error **errp)
 {
     /*
      * Unvisited list elements will be reported later when checking
      * whether unvisited struct members remain.
      */
+    return true;
 }
 
 
@@ -341,7 +346,7 @@
 }
 
 
-static void
+static bool
 opts_type_str(Visitor *v, const char *name, char **obj, Error **errp)
 {
     OptsVisitor *ov = to_ov(v);
@@ -350,7 +355,7 @@
     opt = lookup_scalar(ov, name, errp);
     if (!opt) {
         *obj = NULL;
-        return;
+        return false;
     }
     *obj = g_strdup(opt->str ? opt->str : "");
     /* Note that we consume a string even if this is called as part of
@@ -359,11 +364,12 @@
      * consumed only matters to visit_end_struct() as the final error
      * check if there were no other failures during the visit.  */
     processed(ov, name);
+    return true;
 }
 
 
 /* mimics qemu-option.c::parse_option_bool() */
-static void
+static bool
 opts_type_bool(Visitor *v, const char *name, bool *obj, Error **errp)
 {
     OptsVisitor *ov = to_ov(v);
@@ -371,7 +377,7 @@
 
     opt = lookup_scalar(ov, name, errp);
     if (!opt) {
-        return;
+        return false;
     }
 
     if (opt->str) {
@@ -386,17 +392,18 @@
         } else {
             error_setg(errp, QERR_INVALID_PARAMETER_VALUE, opt->name,
                        "on|yes|y|off|no|n");
-            return;
+            return false;
         }
     } else {
         *obj = true;
     }
 
     processed(ov, name);
+    return true;
 }
 
 
-static void
+static bool
 opts_type_int64(Visitor *v, const char *name, int64_t *obj, Error **errp)
 {
     OptsVisitor *ov = to_ov(v);
@@ -407,12 +414,12 @@
 
     if (ov->list_mode == LM_SIGNED_INTERVAL) {
         *obj = ov->range_next.s;
-        return;
+        return true;
     }
 
     opt = lookup_scalar(ov, name, errp);
     if (!opt) {
-        return;
+        return false;
     }
     str = opt->str ? opt->str : "";
 
@@ -425,7 +432,7 @@
         if (*endptr == '\0') {
             *obj = val;
             processed(ov, name);
-            return;
+            return true;
         }
         if (*endptr == '-' && ov->list_mode == LM_IN_PROGRESS) {
             long long val2;
@@ -442,17 +449,18 @@
 
                 /* as if entering on the top */
                 *obj = ov->range_next.s;
-                return;
+                return true;
             }
         }
     }
     error_setg(errp, QERR_INVALID_PARAMETER_VALUE, opt->name,
                (ov->list_mode == LM_NONE) ? "an int64 value" :
                                             "an int64 value or range");
+    return false;
 }
 
 
-static void
+static bool
 opts_type_uint64(Visitor *v, const char *name, uint64_t *obj, Error **errp)
 {
     OptsVisitor *ov = to_ov(v);
@@ -463,12 +471,12 @@
 
     if (ov->list_mode == LM_UNSIGNED_INTERVAL) {
         *obj = ov->range_next.u;
-        return;
+        return true;
     }
 
     opt = lookup_scalar(ov, name, errp);
     if (!opt) {
-        return;
+        return false;
     }
     str = opt->str;
 
@@ -479,7 +487,7 @@
         if (*endptr == '\0') {
             *obj = val;
             processed(ov, name);
-            return;
+            return true;
         }
         if (*endptr == '-' && ov->list_mode == LM_IN_PROGRESS) {
             unsigned long long val2;
@@ -494,17 +502,18 @@
 
                 /* as if entering on the top */
                 *obj = ov->range_next.u;
-                return;
+                return true;
             }
         }
     }
     error_setg(errp, QERR_INVALID_PARAMETER_VALUE, opt->name,
                (ov->list_mode == LM_NONE) ? "a uint64 value" :
                                             "a uint64 value or range");
+    return false;
 }
 
 
-static void
+static bool
 opts_type_size(Visitor *v, const char *name, uint64_t *obj, Error **errp)
 {
     OptsVisitor *ov = to_ov(v);
@@ -513,17 +522,18 @@
 
     opt = lookup_scalar(ov, name, errp);
     if (!opt) {
-        return;
+        return false;
     }
 
     err = qemu_strtosz(opt->str ? opt->str : "", NULL, obj);
     if (err < 0) {
         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, opt->name,
                    "a size value");
-        return;
+        return false;
     }
 
     processed(ov, name);
+    return true;
 }