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>

1 files changed, 88 insertions, 77 deletions

diff --git a/qapi/qapi-visit-core.c b/qapi/qapi-visit-core.c
index 74aa9c04bd..5a9c47aabf 100644
--- a/qapi/qapi-visit-core.c
+++ b/qapi/qapi-visit-core.c
@@ -36,7 +36,7 @@ void visit_free(Visitor *v)
     }
 }
 
-void visit_start_struct(Visitor *v, const char *name, void **obj,
+bool visit_start_struct(Visitor *v, const char *name, void **obj,
                         size_t size, Error **errp)
 {
     Error *err = NULL;
@@ -51,14 +51,13 @@ void visit_start_struct(Visitor *v, const char *name, void **obj,
         assert(!err != !*obj);
     }
     error_propagate(errp, err);
+    return !err;
 }
 
-void visit_check_struct(Visitor *v, Error **errp)
+bool visit_check_struct(Visitor *v, Error **errp)
 {
     trace_visit_check_struct(v);
-    if (v->check_struct) {
-        v->check_struct(v, errp);
-    }
+    return v->check_struct ? v->check_struct(v, errp) : true;
 }
 
 void visit_end_struct(Visitor *v, void **obj)
@@ -67,7 +66,7 @@ void visit_end_struct(Visitor *v, void **obj)
     v->end_struct(v, obj);
 }
 
-void visit_start_list(Visitor *v, const char *name, GenericList **list,
+bool visit_start_list(Visitor *v, const char *name, GenericList **list,
                       size_t size, Error **errp)
 {
     Error *err = NULL;
@@ -79,6 +78,7 @@ void visit_start_list(Visitor *v, const char *name, GenericList **list,
         assert(!(err && *list));
     }
     error_propagate(errp, err);
+    return !err;
 }
 
 GenericList *visit_next_list(Visitor *v, GenericList *tail, size_t size)
@@ -88,12 +88,10 @@ GenericList *visit_next_list(Visitor *v, GenericList *tail, size_t size)
     return v->next_list(v, tail, size);
 }
 
-void visit_check_list(Visitor *v, Error **errp)
+bool visit_check_list(Visitor *v, Error **errp)
 {
     trace_visit_check_list(v);
-    if (v->check_list) {
-        v->check_list(v, errp);
-    }
+    return v->check_list ? v->check_list(v, errp) : true;
 }
 
 void visit_end_list(Visitor *v, void **obj)
@@ -102,7 +100,7 @@ void visit_end_list(Visitor *v, void **obj)
     v->end_list(v, obj);
 }
 
-void visit_start_alternate(Visitor *v, const char *name,
+bool visit_start_alternate(Visitor *v, const char *name,
                            GenericAlternate **obj, size_t size,
                            Error **errp)
 {
@@ -118,6 +116,7 @@ void visit_start_alternate(Visitor *v, const char *name,
         assert(v->start_alternate && !err != !*obj);
     }
     error_propagate(errp, err);
+    return !err;
 }
 
 void visit_end_alternate(Visitor *v, void **obj)
@@ -147,155 +146,168 @@ bool visit_is_dealloc(Visitor *v)
     return v->type == VISITOR_DEALLOC;
 }
 
-void visit_type_int(Visitor *v, const char *name, int64_t *obj, Error **errp)
+bool visit_type_int(Visitor *v, const char *name, int64_t *obj, Error **errp)
 {
     assert(obj);
     trace_visit_type_int(v, name, obj);
-    v->type_int64(v, name, obj, errp);
+    return v->type_int64(v, name, obj, errp);
 }
 
-static void visit_type_uintN(Visitor *v, uint64_t *obj, const char *name,
+static bool visit_type_uintN(Visitor *v, uint64_t *obj, const char *name,
                              uint64_t max, const char *type, Error **errp)
 {
-    Error *err = NULL;
     uint64_t value = *obj;
 
     assert(v->type == VISITOR_INPUT || value <= max);
 
-    v->type_uint64(v, name, &value, &err);
-    if (err) {
-        error_propagate(errp, err);
-    } else if (value > max) {
+    if (!v->type_uint64(v, name, &value, errp)) {
+        return false;
+    }
+    if (value > max) {
         assert(v->type == VISITOR_INPUT);
         error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
                    name ? name : "null", type);
-    } else {
-        *obj = value;
+        return false;
     }
+    *obj = value;
+    return true;
 }
 
-void visit_type_uint8(Visitor *v, const char *name, uint8_t *obj,
+bool visit_type_uint8(Visitor *v, const char *name, uint8_t *obj,
                       Error **errp)
 {
     uint64_t value;
+    bool ok;
 
     trace_visit_type_uint8(v, name, obj);
     value = *obj;
-    visit_type_uintN(v, &value, name, UINT8_MAX, "uint8_t", errp);
+    ok = visit_type_uintN(v, &value, name, UINT8_MAX, "uint8_t", errp);
     *obj = value;
+    return ok;
 }
 
-void visit_type_uint16(Visitor *v, const char *name, uint16_t *obj,
+bool visit_type_uint16(Visitor *v, const char *name, uint16_t *obj,
                        Error **errp)
 {
     uint64_t value;
+    bool ok;
 
     trace_visit_type_uint16(v, name, obj);
     value = *obj;
-    visit_type_uintN(v, &value, name, UINT16_MAX, "uint16_t", errp);
+    ok = visit_type_uintN(v, &value, name, UINT16_MAX, "uint16_t", errp);
     *obj = value;
+    return ok;
 }
 
-void visit_type_uint32(Visitor *v, const char *name, uint32_t *obj,
+bool visit_type_uint32(Visitor *v, const char *name, uint32_t *obj,
                        Error **errp)
 {
     uint64_t value;
+    bool ok;
 
     trace_visit_type_uint32(v, name, obj);
     value = *obj;
-    visit_type_uintN(v, &value, name, UINT32_MAX, "uint32_t", errp);
+    ok = visit_type_uintN(v, &value, name, UINT32_MAX, "uint32_t", errp);
     *obj = value;
+    return ok;
 }
 
-void visit_type_uint64(Visitor *v, const char *name, uint64_t *obj,
+bool visit_type_uint64(Visitor *v, const char *name, uint64_t *obj,
                        Error **errp)
 {
     assert(obj);
     trace_visit_type_uint64(v, name, obj);
-    v->type_uint64(v, name, obj, errp);
+    return v->type_uint64(v, name, obj, errp);
 }
 
-static void visit_type_intN(Visitor *v, int64_t *obj, const char *name,
+static bool visit_type_intN(Visitor *v, int64_t *obj, const char *name,
                             int64_t min, int64_t max, const char *type,
                             Error **errp)
 {
-    Error *err = NULL;
     int64_t value = *obj;
 
     assert(v->type == VISITOR_INPUT || (value >= min && value <= max));
 
-    v->type_int64(v, name, &value, &err);
-    if (err) {
-        error_propagate(errp, err);
-    } else if (value < min || value > max) {
+    if (!v->type_int64(v, name, &value, errp)) {
+        return false;
+    }
+    if (value < min || value > max) {
         assert(v->type == VISITOR_INPUT);
         error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
                    name ? name : "null", type);
-    } else {
-        *obj = value;
+        return false;
     }
+    *obj = value;
+    return true;
 }
 
-void visit_type_int8(Visitor *v, const char *name, int8_t *obj, Error **errp)
+bool visit_type_int8(Visitor *v, const char *name, int8_t *obj, Error **errp)
 {
     int64_t value;
+    bool ok;
 
     trace_visit_type_int8(v, name, obj);
     value = *obj;
-    visit_type_intN(v, &value, name, INT8_MIN, INT8_MAX, "int8_t", errp);
+    ok = visit_type_intN(v, &value, name, INT8_MIN, INT8_MAX, "int8_t", errp);
     *obj = value;
+    return ok;
 }
 
-void visit_type_int16(Visitor *v, const char *name, int16_t *obj,
+bool visit_type_int16(Visitor *v, const char *name, int16_t *obj,
                       Error **errp)
 {
     int64_t value;
+    bool ok;
 
     trace_visit_type_int16(v, name, obj);
     value = *obj;
-    visit_type_intN(v, &value, name, INT16_MIN, INT16_MAX, "int16_t", errp);
+    ok = visit_type_intN(v, &value, name, INT16_MIN, INT16_MAX, "int16_t",
+                         errp);
     *obj = value;
+    return ok;
 }
 
-void visit_type_int32(Visitor *v, const char *name, int32_t *obj,
+bool visit_type_int32(Visitor *v, const char *name, int32_t *obj,
                       Error **errp)
 {
     int64_t value;
+    bool ok;
 
     trace_visit_type_int32(v, name, obj);
     value = *obj;
-    visit_type_intN(v, &value, name, INT32_MIN, INT32_MAX, "int32_t", errp);
+    ok = visit_type_intN(v, &value, name, INT32_MIN, INT32_MAX, "int32_t",
+                        errp);
     *obj = value;
+    return ok;
 }
 
-void visit_type_int64(Visitor *v, const char *name, int64_t *obj,
+bool visit_type_int64(Visitor *v, const char *name, int64_t *obj,
                       Error **errp)
 {
     assert(obj);
     trace_visit_type_int64(v, name, obj);
-    v->type_int64(v, name, obj, errp);
+    return v->type_int64(v, name, obj, errp);
 }
 
-void visit_type_size(Visitor *v, const char *name, uint64_t *obj,
+bool visit_type_size(Visitor *v, const char *name, uint64_t *obj,
                      Error **errp)
 {
     assert(obj);
     trace_visit_type_size(v, name, obj);
     if (v->type_size) {
-        v->type_size(v, name, obj, errp);
-    } else {
-        v->type_uint64(v, name, obj, errp);
+        return v->type_size(v, name, obj, errp);
     }
+    return v->type_uint64(v, name, obj, errp);
 }
 
-void visit_type_bool(Visitor *v, const char *name, bool *obj, Error **errp)
+bool visit_type_bool(Visitor *v, const char *name, bool *obj, Error **errp)
 {
     assert(obj);
     trace_visit_type_bool(v, name, obj);
-    v->type_bool(v, name, obj, errp);
+    return v->type_bool(v, name, obj, errp);
 }
 
-void visit_type_str(Visitor *v, const char *name, char **obj, Error **errp)
+bool visit_type_str(Visitor *v, const char *name, char **obj, Error **errp)
 {
     Error *err = NULL;
 
@@ -310,89 +322,88 @@ void visit_type_str(Visitor *v, const char *name, char **obj, Error **errp)
         assert(!err != !*obj);
     }
     error_propagate(errp, err);
+    return !err;
 }
 
-void visit_type_number(Visitor *v, const char *name, double *obj,
+bool visit_type_number(Visitor *v, const char *name, double *obj,
                        Error **errp)
 {
     assert(obj);
     trace_visit_type_number(v, name, obj);
-    v->type_number(v, name, obj, errp);
+    return v->type_number(v, name, obj, errp);
 }
 
-void visit_type_any(Visitor *v, const char *name, QObject **obj, Error **errp)
+bool visit_type_any(Visitor *v, const char *name, QObject **obj, Error **errp)
 {
-    Error *err = NULL;
+    bool ok;
 
     assert(obj);
     assert(v->type != VISITOR_OUTPUT || *obj);
     trace_visit_type_any(v, name, obj);
-    v->type_any(v, name, obj, &err);
+    ok = v->type_any(v, name, obj, errp);
     if (v->type == VISITOR_INPUT) {
-        assert(!err != !*obj);
+        assert(ok != !*obj);
     }
-    error_propagate(errp, err);
+    return ok;
 }
 
-void visit_type_null(Visitor *v, const char *name, QNull **obj,
+bool visit_type_null(Visitor *v, const char *name, QNull **obj,
                      Error **errp)
 {
     trace_visit_type_null(v, name, obj);
-    v->type_null(v, name, obj, errp);
+    return v->type_null(v, name, obj, errp);
 }
 
-static void output_type_enum(Visitor *v, const char *name, int *obj,
+static bool output_type_enum(Visitor *v, const char *name, int *obj,
                              const QEnumLookup *lookup, Error **errp)
 {
     int value = *obj;
     char *enum_str;
 
     enum_str = (char *)qapi_enum_lookup(lookup, value);
-    visit_type_str(v, name, &enum_str, errp);
+    return visit_type_str(v, name, &enum_str, errp);
 }
 
-static void input_type_enum(Visitor *v, const char *name, int *obj,
+static bool input_type_enum(Visitor *v, const char *name, int *obj,
                             const QEnumLookup *lookup, Error **errp)
 {
-    Error *local_err = NULL;
     int64_t value;
     char *enum_str;
 
-    visit_type_str(v, name, &enum_str, &local_err);
-    if (local_err) {
-        error_propagate(errp, local_err);
-        return;
+    if (!visit_type_str(v, name, &enum_str, errp)) {
+        return false;
     }
 
     value = qapi_enum_parse(lookup, enum_str, -1, NULL);
     if (value < 0) {
         error_setg(errp, QERR_INVALID_PARAMETER, enum_str);
         g_free(enum_str);
-        return;
+        return false;
     }
 
     g_free(enum_str);
     *obj = value;
+    return true;
 }
 
-void visit_type_enum(Visitor *v, const char *name, int *obj,
+bool visit_type_enum(Visitor *v, const char *name, int *obj,
                      const QEnumLookup *lookup, Error **errp)
 {
     assert(obj && lookup);
     trace_visit_type_enum(v, name, obj);
     switch (v->type) {
     case VISITOR_INPUT:
-        input_type_enum(v, name, obj, lookup, errp);
-        break;
+        return input_type_enum(v, name, obj, lookup, errp);
     case VISITOR_OUTPUT:
-        output_type_enum(v, name, obj, lookup, errp);
-        break;
+        return output_type_enum(v, name, obj, lookup, errp);
     case VISITOR_CLONE:
         /* nothing further to do, scalar value was already copied by
          * g_memdup() during visit_start_*() */
-        break;
+        return true;
     case VISITOR_DEALLOC:
         /* nothing to deallocate for a scalar */
-        break;
+        return true;
+    default:
+        abort();
     }
 }