[PATCH] ui: drop VNC feature _MASK constants

["Daniel P. Berrangé" <berrange@redhat.com>]

Each VNC feature enum entry has a corresponding _MASK constant
which is the bit-shifted value. It is very easy for contributors
to accidentally use the _MASK constant, instead of the non-_MASK
constant, or the reverse. No compiler warning is possible and
it'll just silently do the wrong thing at runtime.

By introducing the vnc_set_feature helper method, we can drop
all the _MASK constants and thus prevent any future accidents.

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
---
 ui/vnc.c | 34 +++++++++++++++++-----------------
 ui/vnc.h | 21 ++++-----------------
 2 files changed, 21 insertions(+), 34 deletions(-)

diff --git a/ui/vnc.c b/ui/vnc.c
index 4f23a0fa79..3db87fd89c 100644
--- a/ui/vnc.c
+++ b/ui/vnc.c
@@ -2144,16 +2144,16 @@ static void set_encodings(VncState *vs, int32_t *encodings, size_t n_encodings)
             vs->vnc_encoding = enc;
             break;
         case VNC_ENCODING_HEXTILE:
-            vs->features |= VNC_FEATURE_HEXTILE_MASK;
+            vnc_set_feature(vs, VNC_FEATURE_HEXTILE);
             vs->vnc_encoding = enc;
             break;
         case VNC_ENCODING_TIGHT:
-            vs->features |= VNC_FEATURE_TIGHT_MASK;
+            vnc_set_feature(vs, VNC_FEATURE_TIGHT);
             vs->vnc_encoding = enc;
             break;
 #ifdef CONFIG_PNG
         case VNC_ENCODING_TIGHT_PNG:
-            vs->features |= VNC_FEATURE_TIGHT_PNG_MASK;
+            vnc_set_feature(vs, VNC_FEATURE_TIGHT_PNG);
             vs->vnc_encoding = enc;
             break;
 #endif
@@ -2163,57 +2163,57 @@ static void set_encodings(VncState *vs, int32_t *encodings, size_t n_encodings)
              * So prioritize ZRLE, even if the client hints that it prefers
              * ZLIB.
              */
-            if ((vs->features & VNC_FEATURE_ZRLE_MASK) == 0) {
-                vs->features |= VNC_FEATURE_ZLIB_MASK;
+            if (!vnc_has_feature(vs, VNC_FEATURE_ZRLE)) {
+                vnc_set_feature(vs, VNC_FEATURE_ZLIB);
                 vs->vnc_encoding = enc;
             }
             break;
         case VNC_ENCODING_ZRLE:
-            vs->features |= VNC_FEATURE_ZRLE_MASK;
+            vnc_set_feature(vs, VNC_FEATURE_ZRLE);
             vs->vnc_encoding = enc;
             break;
         case VNC_ENCODING_ZYWRLE:
-            vs->features |= VNC_FEATURE_ZYWRLE_MASK;
+            vnc_set_feature(vs, VNC_FEATURE_ZYWRLE);
             vs->vnc_encoding = enc;
             break;
         case VNC_ENCODING_DESKTOPRESIZE:
-            vs->features |= VNC_FEATURE_RESIZE_MASK;
+            vnc_set_feature(vs, VNC_FEATURE_RESIZE);
             break;
         case VNC_ENCODING_DESKTOP_RESIZE_EXT:
-            vs->features |= VNC_FEATURE_RESIZE_EXT_MASK;
+            vnc_set_feature(vs, VNC_FEATURE_RESIZE_EXT);
             break;
         case VNC_ENCODING_POINTER_TYPE_CHANGE:
-            vs->features |= VNC_FEATURE_POINTER_TYPE_CHANGE_MASK;
+            vnc_set_feature(vs, VNC_FEATURE_POINTER_TYPE_CHANGE);
             break;
         case VNC_ENCODING_RICH_CURSOR:
-            vs->features |= VNC_FEATURE_RICH_CURSOR_MASK;
+            vnc_set_feature(vs, VNC_FEATURE_RICH_CURSOR);
             break;
         case VNC_ENCODING_ALPHA_CURSOR:
-            vs->features |= VNC_FEATURE_ALPHA_CURSOR_MASK;
+            vnc_set_feature(vs, VNC_FEATURE_ALPHA_CURSOR);
             break;
         case VNC_ENCODING_EXT_KEY_EVENT:
             send_ext_key_event_ack(vs);
             break;
         case VNC_ENCODING_AUDIO:
             if (vs->vd->audio_state) {
-                vs->features |= VNC_FEATURE_AUDIO_MASK;
+                vnc_set_feature(vs, VNC_FEATURE_AUDIO);
                 send_ext_audio_ack(vs);
             }
             break;
         case VNC_ENCODING_WMVi:
-            vs->features |= VNC_FEATURE_WMVI_MASK;
+            vnc_set_feature(vs, VNC_FEATURE_WMVI);
             break;
         case VNC_ENCODING_LED_STATE:
-            vs->features |= VNC_FEATURE_LED_STATE_MASK;
+            vnc_set_feature(vs, VNC_FEATURE_LED_STATE);
             break;
         case VNC_ENCODING_XVP:
             if (vs->vd->power_control) {
-                vs->features |= VNC_FEATURE_XVP_MASK;
+                vnc_set_feature(vs, VNC_FEATURE_XVP);
                 send_xvp_message(vs, VNC_XVP_CODE_INIT);
             }
             break;
         case VNC_ENCODING_CLIPBOARD_EXT:
-            vs->features |= VNC_FEATURE_CLIPBOARD_EXT_MASK;
+            vnc_set_feature(vs, VNC_FEATURE_CLIPBOARD_EXT);
             vnc_server_cut_text_caps(vs);
             break;
         case VNC_ENCODING_COMPRESSLEVEL0 ... VNC_ENCODING_COMPRESSLEVEL0 + 9:
diff --git a/ui/vnc.h b/ui/vnc.h
index 96d19dce19..8b88555ff2 100644
--- a/ui/vnc.h
+++ b/ui/vnc.h
@@ -467,23 +467,6 @@ enum VncFeatures {
     VNC_FEATURE_AUDIO,
 };
 
-#define VNC_FEATURE_RESIZE_MASK              (1 << VNC_FEATURE_RESIZE)
-#define VNC_FEATURE_RESIZE_EXT_MASK          (1 << VNC_FEATURE_RESIZE_EXT)
-#define VNC_FEATURE_HEXTILE_MASK             (1 << VNC_FEATURE_HEXTILE)
-#define VNC_FEATURE_POINTER_TYPE_CHANGE_MASK (1 << VNC_FEATURE_POINTER_TYPE_CHANGE)
-#define VNC_FEATURE_WMVI_MASK                (1 << VNC_FEATURE_WMVI)
-#define VNC_FEATURE_TIGHT_MASK               (1 << VNC_FEATURE_TIGHT)
-#define VNC_FEATURE_ZLIB_MASK                (1 << VNC_FEATURE_ZLIB)
-#define VNC_FEATURE_RICH_CURSOR_MASK         (1 << VNC_FEATURE_RICH_CURSOR)
-#define VNC_FEATURE_ALPHA_CURSOR_MASK        (1 << VNC_FEATURE_ALPHA_CURSOR)
-#define VNC_FEATURE_TIGHT_PNG_MASK           (1 << VNC_FEATURE_TIGHT_PNG)
-#define VNC_FEATURE_ZRLE_MASK                (1 << VNC_FEATURE_ZRLE)
-#define VNC_FEATURE_ZYWRLE_MASK              (1 << VNC_FEATURE_ZYWRLE)
-#define VNC_FEATURE_LED_STATE_MASK           (1 << VNC_FEATURE_LED_STATE)
-#define VNC_FEATURE_XVP_MASK                 (1 << VNC_FEATURE_XVP)
-#define VNC_FEATURE_CLIPBOARD_EXT_MASK       (1 <<  VNC_FEATURE_CLIPBOARD_EXT)
-#define VNC_FEATURE_AUDIO_MASK               (1 <<  VNC_FEATURE_AUDIO)
-
 
 /* Client -> Server message IDs */
 #define VNC_MSG_CLIENT_SET_PIXEL_FORMAT           0
@@ -599,6 +582,10 @@ static inline uint32_t vnc_has_feature(VncState *vs, int feature) {
     return (vs->features & (1 << feature));
 }
 
+static inline void vnc_set_feature(VncState *vs, int feature) {
+    vs->features |= (1 << feature);
+}
+
 /* Framebuffer */
 void vnc_framebuffer_update(VncState *vs, int x, int y, int w, int h,
                             int32_t encoding);
-- 
2.43.0