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>

4 files changed, 59 insertions, 29 deletions

diff --git a/hw/display/blizzard_template.h b/hw/display/blizzard_template.h
index a8a8899478..b7ef27c808 100644
--- a/hw/display/blizzard_template.h
+++ b/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
diff --git a/hw/display/pl110_template.h b/hw/display/pl110_template.h
index e738e4a241..36ba791c6f 100644
--- a/hw/display/pl110_template.h
+++ b/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
diff --git a/hw/display/pxa2xx_template.h b/hw/display/pxa2xx_template.h
index 1cbe36cb80..c64eebc4b6 100644
--- a/hw/display/pxa2xx_template.h
+++ b/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
diff --git a/hw/display/tc6393xb_template.h b/hw/display/tc6393xb_template.h
index 154aafd400..78629c07f9 100644
--- a/hw/display/tc6393xb_template.h
+++ b/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