qapi: Consolidate visitor small integer callbacks

Commit 4e27e819 introduced optional visitor callbacks for all
sorts of int types, but no visitor has supplied any of the
callbacks for sizes less than 64 bits.  In other words, the
generic implementation based on using type_[u]int64() followed
by bounds-checking works just fine. In the interest of
simplicity, it's easier to make the visitor callback interface
not have to worry about the other sizes.

Adding some helper functions minimizes the boilerplate required
to correct FIXMEs added earlier with regards to questionable
reuse of errp, particularly now that we can guarantee from a
single file audit that value is unchanged if an error is set.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1454075341-13658-16-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

2 files changed, 55 insertions, 101 deletions

diff --git a/include/qapi/visitor-impl.h b/include/qapi/visitor-impl.h
index 92c4bcbb90..29e2c087fe 100644
--- a/include/qapi/visitor-impl.h
+++ b/include/qapi/visitor-impl.h
@@ -1,7 +1,7 @@
 /*
  * Core Definitions for QAPI Visitor implementations
  *
- * Copyright (C) 2012 Red Hat, Inc.
+ * Copyright (C) 2012-2016 Red Hat, Inc.
  *
  * Author: Paolo Bonizni <pbonzini@redhat.com>
  *
@@ -56,12 +56,6 @@ struct Visitor
     /* May be NULL; most useful for input visitors. */
     void (*optional)(Visitor *v, bool *present, const char *name);
 
-    void (*type_uint8)(Visitor *v, uint8_t *obj, const char *name, Error **errp);
-    void (*type_uint16)(Visitor *v, uint16_t *obj, const char *name, Error **errp);
-    void (*type_uint32)(Visitor *v, uint32_t *obj, const char *name, Error **errp);
-    void (*type_int8)(Visitor *v, int8_t *obj, const char *name, Error **errp);
-    void (*type_int16)(Visitor *v, int16_t *obj, const char *name, Error **errp);
-    void (*type_int32)(Visitor *v, int32_t *obj, const char *name, Error **errp);
     bool (*start_union)(Visitor *v, bool data_present, Error **errp);
 };
 
diff --git a/qapi/qapi-visit-core.c b/qapi/qapi-visit-core.c
index afcd59be9a..7228dc2350 100644
--- a/qapi/qapi-visit-core.c
+++ b/qapi/qapi-visit-core.c
@@ -95,129 +95,89 @@ void visit_type_int(Visitor *v, int64_t *obj, const char *name, Error **errp)
     v->type_int64(v, obj, name, errp);
 }
 
-void visit_type_uint8(Visitor *v, uint8_t *obj, const char *name, Error **errp)
+static void visit_type_uintN(Visitor *v, uint64_t *obj, const char *name,
+                             uint64_t max, const char *type, Error **errp)
 {
-    uint64_t value;
-
-    if (v->type_uint8) {
-        v->type_uint8(v, obj, name, errp);
+    Error *err = NULL;
+    uint64_t value = *obj;
+
+    v->type_uint64(v, &value, name, &err);
+    if (err) {
+        error_propagate(errp, err);
+    } else if (value > max) {
+        error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
+                   name ? name : "null", type);
     } else {
-        value = *obj;
-        v->type_uint64(v, &value, name, errp);
-        if (value > UINT8_MAX) {
-            /* FIXME questionable reuse of errp if callback changed
-               value on error */
-            error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
-                       name ? name : "null", "uint8_t");
-            return;
-        }
         *obj = value;
     }
 }
 
-void visit_type_uint16(Visitor *v, uint16_t *obj, const char *name, Error **errp)
+void visit_type_uint8(Visitor *v, uint8_t *obj, const char *name, Error **errp)
 {
-    uint64_t value;
-
-    if (v->type_uint16) {
-        v->type_uint16(v, obj, name, errp);
-    } else {
-        value = *obj;
-        v->type_uint64(v, &value, name, errp);
-        if (value > UINT16_MAX) {
-            /* FIXME questionable reuse of errp if callback changed
-               value on error */
-            error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
-                       name ? name : "null", "uint16_t");
-            return;
-        }
-        *obj = value;
-    }
+    uint64_t value = *obj;
+    visit_type_uintN(v, &value, name, UINT8_MAX, "uint8_t", errp);
+    *obj = value;
 }
 
-void visit_type_uint32(Visitor *v, uint32_t *obj, const char *name, Error **errp)
+void visit_type_uint16(Visitor *v, uint16_t *obj, const char *name,
+                       Error **errp)
 {
-    uint64_t value;
+    uint64_t value = *obj;
+    visit_type_uintN(v, &value, name, UINT16_MAX, "uint16_t", errp);
+    *obj = value;
+}
 
-    if (v->type_uint32) {
-        v->type_uint32(v, obj, name, errp);
-    } else {
-        value = *obj;
-        v->type_uint64(v, &value, name, errp);
-        if (value > UINT32_MAX) {
-            /* FIXME questionable reuse of errp if callback changed
-               value on error */
-            error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
-                       name ? name : "null", "uint32_t");
-            return;
-        }
-        *obj = value;
-    }
+void visit_type_uint32(Visitor *v, uint32_t *obj, const char *name,
+                       Error **errp)
+{
+    uint64_t value = *obj;
+    visit_type_uintN(v, &value, name, UINT32_MAX, "uint32_t", errp);
+    *obj = value;
 }
 
-void visit_type_uint64(Visitor *v, uint64_t *obj, const char *name, Error **errp)
+void visit_type_uint64(Visitor *v, uint64_t *obj, const char *name,
+                       Error **errp)
 {
     v->type_uint64(v, obj, name, errp);
 }
 
-void visit_type_int8(Visitor *v, int8_t *obj, const char *name, Error **errp)
+static void visit_type_intN(Visitor *v, int64_t *obj, const char *name,
+                            int64_t min, int64_t max, const char *type,
+                            Error **errp)
 {
-    int64_t value;
-
-    if (v->type_int8) {
-        v->type_int8(v, obj, name, errp);
+    Error *err = NULL;
+    int64_t value = *obj;
+
+    v->type_int64(v, &value, name, &err);
+    if (err) {
+        error_propagate(errp, err);
+    } else if (value < min || value > max) {
+        error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
+                   name ? name : "null", type);
     } else {
-        value = *obj;
-        v->type_int64(v, &value, name, errp);
-        if (value < INT8_MIN || value > INT8_MAX) {
-            /* FIXME questionable reuse of errp if callback changed
-               value on error */
-            error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
-                       name ? name : "null", "int8_t");
-            return;
-        }
         *obj = value;
     }
 }
 
-void visit_type_int16(Visitor *v, int16_t *obj, const char *name, Error **errp)
+void visit_type_int8(Visitor *v, int8_t *obj, const char *name, Error **errp)
 {
-    int64_t value;
+    int64_t value = *obj;
+    visit_type_intN(v, &value, name, INT8_MIN, INT8_MAX, "int8_t", errp);
+    *obj = value;
+}
 
-    if (v->type_int16) {
-        v->type_int16(v, obj, name, errp);
-    } else {
-        value = *obj;
-        v->type_int64(v, &value, name, errp);
-        if (value < INT16_MIN || value > INT16_MAX) {
-            /* FIXME questionable reuse of errp if callback changed
-               value on error */
-            error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
-                       name ? name : "null", "int16_t");
-            return;
-        }
-        *obj = value;
-    }
+void visit_type_int16(Visitor *v, int16_t *obj, const char *name, Error **errp)
+{
+    int64_t value = *obj;
+    visit_type_intN(v, &value, name, INT16_MIN, INT16_MAX, "int16_t", errp);
+    *obj = value;
 }
 
 void visit_type_int32(Visitor *v, int32_t *obj, const char *name, Error **errp)
 {
-    int64_t value;
-
-    if (v->type_int32) {
-        v->type_int32(v, obj, name, errp);
-    } else {
-        value = *obj;
-        v->type_int64(v, &value, name, errp);
-        if (value < INT32_MIN || value > INT32_MAX) {
-            /* FIXME questionable reuse of errp if callback changed
-               value on error */
-            error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
-                       name ? name : "null", "int32_t");
-            return;
-        }
-        *obj = value;
-    }
+    int64_t value = *obj;
+    visit_type_intN(v, &value, name, INT32_MIN, INT32_MAX, "int32_t", errp);
+    *obj = value;
 }
 
 void visit_type_int64(Visitor *v, int64_t *obj, const char *name, Error **errp)