display: avoid multi-statement macro

For blizzard, pl110 and tc6393xb this is harmless, but for pxa2xx
Coverity noticed that it is used inside an "if" statement.
Fix it because it's the file with the highest number of defects
in the whole QEMU tree!  Use "do...while (0)", or just remove the
semicolon if there's a single statement in the macro.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

hw/display/blizzard_template.h

@@ -18,25 +18,35 @@
  * with this program; if not, see <http://www.gnu.org/licenses/>.
  */
 
-#define SKIP_PIXEL(to)		to += deststep
+#define SKIP_PIXEL(to)         (to += deststep)
 #if DEPTH == 8
-# define PIXEL_TYPE		uint8_t
-# define COPY_PIXEL(to, from)	*to = from; SKIP_PIXEL(to)
-# define COPY_PIXEL1(to, from)	*to ++ = from
+# define PIXEL_TYPE            uint8_t
+# define COPY_PIXEL(to, from)  do { *to = from; SKIP_PIXEL(to); } while (0)
+# define COPY_PIXEL1(to, from) (*to++ = from)
 #elif DEPTH == 15 || DEPTH == 16
-# define PIXEL_TYPE		uint16_t
-# define COPY_PIXEL(to, from)	*to = from; SKIP_PIXEL(to)
-# define COPY_PIXEL1(to, from)	*to ++ = from
+# define PIXEL_TYPE            uint16_t
+# define COPY_PIXEL(to, from)  do { *to = from; SKIP_PIXEL(to); } while (0)
+# define COPY_PIXEL1(to, from) (*to++ = from)
 #elif DEPTH == 24
-# define PIXEL_TYPE		uint8_t
-# define COPY_PIXEL(to, from)	\
-    to[0] = from; to[1] = (from) >> 8; to[2] = (from) >> 16; SKIP_PIXEL(to)
-# define COPY_PIXEL1(to, from)	\
-    *to ++ = from; *to ++ = (from) >> 8; *to ++ = (from) >> 16
+# define PIXEL_TYPE            uint8_t
+# define COPY_PIXEL(to, from) \
+    do {                      \
+        to[0] = from;         \
+        to[1] = (from) >> 8;  \
+        to[2] = (from) >> 16; \
+        SKIP_PIXEL(to);       \
+    } while (0)
+
+# define COPY_PIXEL1(to, from) \
+    do {                       \
+        *to++ = from;          \
+        *to++ = (from) >> 8;   \
+        *to++ = (from) >> 16;  \
+    } while (0)
 #elif DEPTH == 32
-# define PIXEL_TYPE		uint32_t
-# define COPY_PIXEL(to, from)	*to = from; SKIP_PIXEL(to)
-# define COPY_PIXEL1(to, from)	*to ++ = from
+# define PIXEL_TYPE            uint32_t
+# define COPY_PIXEL(to, from)  do { *to = from; SKIP_PIXEL(to); } while (0)
+# define COPY_PIXEL1(to, from) (*to++ = from)
 #else
 # error unknown bit depth
 #endif

hw/display/pl110_template.h

@@ -14,12 +14,16 @@
 #if BITS == 8
 #define COPY_PIXEL(to, from) *(to++) = from
 #elif BITS == 15 || BITS == 16
-#define COPY_PIXEL(to, from) *(uint16_t *)to = from; to += 2;
+#define COPY_PIXEL(to, from) do { *(uint16_t *)to = from; to += 2; } while (0)
 #elif BITS == 24
-#define COPY_PIXEL(to, from) \
-  *(to++) = from; *(to++) = (from) >> 8; *(to++) = (from) >> 16
+#define COPY_PIXEL(to, from)    \
+    do {                        \
+        *(to++) = from;         \
+        *(to++) = (from) >> 8;  \
+        *(to++) = (from) >> 16; \
+    } while (0)
 #elif BITS == 32
-#define COPY_PIXEL(to, from) *(uint32_t *)to = from; to += 4;
+#define COPY_PIXEL(to, from) do { *(uint32_t *)to = from; to += 4; } while (0)
 #else
 #error unknown bit depth
 #endif

hw/display/pxa2xx_template.h

@@ -11,14 +11,26 @@
 
 # define SKIP_PIXEL(to)		to += deststep
 #if BITS == 8
-# define COPY_PIXEL(to, from)	*to = from; SKIP_PIXEL(to)
+# define COPY_PIXEL(to, from)  do { *to = from; SKIP_PIXEL(to); } while (0)
 #elif BITS == 15 || BITS == 16
-# define COPY_PIXEL(to, from)	*(uint16_t *) to = from; SKIP_PIXEL(to)
+# define COPY_PIXEL(to, from)    \
+    do {                         \
+        *(uint16_t *) to = from; \
+        SKIP_PIXEL(to);          \
+    } while (0)
 #elif BITS == 24
-# define COPY_PIXEL(to, from)	\
-	*(uint16_t *) to = from; *(to + 2) = (from) >> 16; SKIP_PIXEL(to)
+# define COPY_PIXEL(to, from)     \
+    do {                          \
+        *(uint16_t *) to = from;  \
+        *(to + 2) = (from) >> 16; \
+        SKIP_PIXEL(to);           \
+    } while (0)
 #elif BITS == 32
-# define COPY_PIXEL(to, from)	*(uint32_t *) to = from; SKIP_PIXEL(to)
+# define COPY_PIXEL(to, from)    \
+    do {                         \
+        *(uint32_t *) to = from; \
+        SKIP_PIXEL(to);          \
+    } while (0)
 #else
 # error unknown bit depth
 #endif

hw/display/tc6393xb_template.h

@@ -22,14 +22,18 @@
  */
 
 #if BITS == 8
-# define SET_PIXEL(addr, color)	*(uint8_t*)addr = color;
+# define SET_PIXEL(addr, color)  (*(uint8_t *)addr = color)
 #elif BITS == 15 || BITS == 16
-# define SET_PIXEL(addr, color)	*(uint16_t*)addr = color;
+# define SET_PIXEL(addr, color)  (*(uint16_t *)addr = color)
 #elif BITS == 24
-# define SET_PIXEL(addr, color)	\
-    addr[0] = color; addr[1] = (color) >> 8; addr[2] = (color) >> 16;
+# define SET_PIXEL(addr, color)  \
+    do {                         \
+        addr[0] = color;         \
+        addr[1] = (color) >> 8;  \
+        addr[2] = (color) >> 16; \
+    } while (0)
 #elif BITS == 32
-# define SET_PIXEL(addr, color)	*(uint32_t*)addr = color;
+# define SET_PIXEL(addr, color)  (*(uint32_t *)addr = color)
 #else
 # error unknown bit depth
 #endif