[Qemu-devel] [PATCH target-arm v3] display: avoid multi-statement macro

[Paolo Bonzini]

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 <address@hidden>
---
        v1->v2: do not use comma operator
        v2->v3: fix some checkpatch errors

 hw/display/blizzard_template.h | 22 ++++++++++++++++------
 hw/display/pl110_template.h    | 12 ++++++++----
 hw/display/pxa2xx_template.h   | 22 +++++++++++++++++-----
 hw/display/tc6393xb_template.h | 14 +++++++++-----
 4 files changed, 56 insertions(+), 27 deletions(-)

diff --git a/hw/display/blizzard_template.h b/hw/display/blizzard_template.h
index a8a8899..c48a9b3 100644
--- a/hw/display/blizzard_template.h
+++ b/hw/display/blizzard_template.h
@@ -20,23 +20,33 @@
 
-#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 e738e4a..f685b26 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 1cbe36c..9aed90e 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 154aafd..964001f 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
-- 
1.8.4.2