cirrus: avoid write only variables

Compiling with GCC 4.6.0 20100925 produced a lot of warnings like:
In file included from /src/qemu/hw/cirrus_vga_rop.h:174:0,
                 from /src/qemu/hw/cirrus_vga.c:284:
/src/qemu/hw/cirrus_vga_rop2.h: In function 'cirrus_patternfill_0_8':
/src/qemu/hw/cirrus_vga_rop2.h:48:18: error: variable 'col' set but not used [-Werror=unused-but-set-variable]
/src/qemu/hw/cirrus_vga_rop2.h: In function 'cirrus_colorexpand_transp_0_8':
/src/qemu/hw/cirrus_vga_rop2.h:104:18: error: variable 'col' set but not used [-Werror=unused-but-set-variable]

Fix the warnings by introducing an inline function, which avoids
exposing write-only variables.

Signed-off-by: Blue Swirl <blauwirbel@gmail.com>

3 files changed, 51 insertions, 29 deletions

diff --git a/hw/cirrus_vga.c b/hw/cirrus_vga.c
index bbd4b08..aadc56f 100644
--- a/hw/cirrus_vga.c
+++ b/hw/cirrus_vga.c
@@ -280,63 +280,63 @@ static void cirrus_bitblt_fill_nop(CirrusVGAState *s,
 }
 
 #define ROP_NAME 0
-#define ROP_OP(d, s) d = 0
+#define ROP_FN(d, s) 0
 #include "cirrus_vga_rop.h"
 
 #define ROP_NAME src_and_dst
-#define ROP_OP(d, s) d = (s) & (d)
+#define ROP_FN(d, s) (s) & (d)
 #include "cirrus_vga_rop.h"
 
 #define ROP_NAME src_and_notdst
-#define ROP_OP(d, s) d = (s) & (~(d))
+#define ROP_FN(d, s) (s) & (~(d))
 #include "cirrus_vga_rop.h"
 
 #define ROP_NAME notdst
-#define ROP_OP(d, s) d = ~(d)
+#define ROP_FN(d, s) ~(d)
 #include "cirrus_vga_rop.h"
 
 #define ROP_NAME src
-#define ROP_OP(d, s) d = s
+#define ROP_FN(d, s) s
 #include "cirrus_vga_rop.h"
 
 #define ROP_NAME 1
-#define ROP_OP(d, s) d = ~0
+#define ROP_FN(d, s) ~0
 #include "cirrus_vga_rop.h"
 
 #define ROP_NAME notsrc_and_dst
-#define ROP_OP(d, s) d = (~(s)) & (d)
+#define ROP_FN(d, s) (~(s)) & (d)
 #include "cirrus_vga_rop.h"
 
 #define ROP_NAME src_xor_dst
-#define ROP_OP(d, s) d = (s) ^ (d)
+#define ROP_FN(d, s) (s) ^ (d)
 #include "cirrus_vga_rop.h"
 
 #define ROP_NAME src_or_dst
-#define ROP_OP(d, s) d = (s) | (d)
+#define ROP_FN(d, s) (s) | (d)
 #include "cirrus_vga_rop.h"
 
 #define ROP_NAME notsrc_or_notdst
-#define ROP_OP(d, s) d = (~(s)) | (~(d))
+#define ROP_FN(d, s) (~(s)) | (~(d))
 #include "cirrus_vga_rop.h"
 
 #define ROP_NAME src_notxor_dst
-#define ROP_OP(d, s) d = ~((s) ^ (d))
+#define ROP_FN(d, s) ~((s) ^ (d))
 #include "cirrus_vga_rop.h"
 
 #define ROP_NAME src_or_notdst
-#define ROP_OP(d, s) d = (s) | (~(d))
+#define ROP_FN(d, s) (s) | (~(d))
 #include "cirrus_vga_rop.h"
 
 #define ROP_NAME notsrc
-#define ROP_OP(d, s) d = (~(s))
+#define ROP_FN(d, s) (~(s))
 #include "cirrus_vga_rop.h"
 
 #define ROP_NAME notsrc_or_dst
-#define ROP_OP(d, s) d = (~(s)) | (d)
+#define ROP_FN(d, s) (~(s)) | (d)
 #include "cirrus_vga_rop.h"
 
 #define ROP_NAME notsrc_and_notdst
-#define ROP_OP(d, s) d = (~(s)) & (~(d))
+#define ROP_FN(d, s) (~(s)) & (~(d))
 #include "cirrus_vga_rop.h"
 
 static const cirrus_bitblt_rop_t cirrus_fwd_rop[16] = {
diff --git a/hw/cirrus_vga_rop.h b/hw/cirrus_vga_rop.h
index 39a7b72..9c7bb09 100644
--- a/hw/cirrus_vga_rop.h
+++ b/hw/cirrus_vga_rop.h
@@ -22,6 +22,26 @@
  * THE SOFTWARE.
  */
 
+static inline void glue(rop_8_,ROP_NAME)(uint8_t *dst, uint8_t src)
+{
+    *dst = ROP_FN(*dst, src);
+}
+
+static inline void glue(rop_16_,ROP_NAME)(uint16_t *dst, uint16_t src)
+{
+    *dst = ROP_FN(*dst, src);
+}
+
+static inline void glue(rop_32_,ROP_NAME)(uint32_t *dst, uint32_t src)
+{
+    *dst = ROP_FN(*dst, src);
+}
+
+#define ROP_OP(d, s) glue(rop_8_,ROP_NAME)(d, s)
+#define ROP_OP_16(d, s) glue(rop_16_,ROP_NAME)(d, s)
+#define ROP_OP_32(d, s) glue(rop_32_,ROP_NAME)(d, s)
+#undef ROP_FN
+
 static void
 glue(cirrus_bitblt_rop_fwd_, ROP_NAME)(CirrusVGAState *s,
                              uint8_t *dst,const uint8_t *src,
@@ -39,7 +59,7 @@ glue(cirrus_bitblt_rop_fwd_, ROP_NAME)(CirrusVGAState *s,
 
     for (y = 0; y < bltheight; y++) {
         for (x = 0; x < bltwidth; x++) {
-            ROP_OP(*dst, *src);
+            ROP_OP(dst, *src);
             dst++;
             src++;
         }
@@ -59,7 +79,7 @@ glue(cirrus_bitblt_rop_bkwd_, ROP_NAME)(CirrusVGAState *s,
     srcpitch += bltwidth;
     for (y = 0; y < bltheight; y++) {
         for (x = 0; x < bltwidth; x++) {
-            ROP_OP(*dst, *src);
+            ROP_OP(dst, *src);
             dst--;
             src--;
         }
@@ -81,7 +101,7 @@ glue(glue(cirrus_bitblt_rop_fwd_transp_, ROP_NAME),_8)(CirrusVGAState *s,
     for (y = 0; y < bltheight; y++) {
         for (x = 0; x < bltwidth; x++) {
 	    p = *dst;
-            ROP_OP(p, *src);
+            ROP_OP(&p, *src);
 	    if (p != s->vga.gr[0x34]) *dst = p;
             dst++;
             src++;
@@ -104,7 +124,7 @@ glue(glue(cirrus_bitblt_rop_bkwd_transp_, ROP_NAME),_8)(CirrusVGAState *s,
     for (y = 0; y < bltheight; y++) {
         for (x = 0; x < bltwidth; x++) {
 	    p = *dst;
-            ROP_OP(p, *src);
+            ROP_OP(&p, *src);
 	    if (p != s->vga.gr[0x34]) *dst = p;
             dst--;
             src--;
@@ -128,8 +148,8 @@ glue(glue(cirrus_bitblt_rop_fwd_transp_, ROP_NAME),_16)(CirrusVGAState *s,
         for (x = 0; x < bltwidth; x+=2) {
 	    p1 = *dst;
 	    p2 = *(dst+1);
-            ROP_OP(p1, *src);
-            ROP_OP(p2, *(src+1));
+            ROP_OP(&p1, *src);
+            ROP_OP(&p2, *(src + 1));
 	    if ((p1 != s->vga.gr[0x34]) || (p2 != s->vga.gr[0x35])) {
 		*dst = p1;
 		*(dst+1) = p2;
@@ -156,8 +176,8 @@ glue(glue(cirrus_bitblt_rop_bkwd_transp_, ROP_NAME),_16)(CirrusVGAState *s,
         for (x = 0; x < bltwidth; x+=2) {
 	    p1 = *(dst-1);
 	    p2 = *dst;
-            ROP_OP(p1, *(src-1));
-            ROP_OP(p2, *src);
+            ROP_OP(&p1, *(src - 1));
+            ROP_OP(&p2, *src);
 	    if ((p1 != s->vga.gr[0x34]) || (p2 != s->vga.gr[0x35])) {
 		*(dst-1) = p1;
 		*dst = p2;
@@ -184,3 +204,5 @@ glue(glue(cirrus_bitblt_rop_bkwd_transp_, ROP_NAME),_16)(CirrusVGAState *s,
 
 #undef ROP_NAME
 #undef ROP_OP
+#undef ROP_OP_16
+#undef ROP_OP_32
diff --git a/hw/cirrus_vga_rop2.h b/hw/cirrus_vga_rop2.h
index 81a5b39..d28bcc6 100644
--- a/hw/cirrus_vga_rop2.h
+++ b/hw/cirrus_vga_rop2.h
@@ -23,15 +23,15 @@
  */
 
 #if DEPTH == 8
-#define PUTPIXEL()    ROP_OP(d[0], col)
+#define PUTPIXEL()    ROP_OP(&d[0], col)
 #elif DEPTH == 16
-#define PUTPIXEL()    ROP_OP(((uint16_t *)d)[0], col);
+#define PUTPIXEL()    ROP_OP_16((uint16_t *)&d[0], col)
 #elif DEPTH == 24
-#define PUTPIXEL()    ROP_OP(d[0], col); \
-                      ROP_OP(d[1], (col >> 8)); \
-                      ROP_OP(d[2], (col >> 16))
+#define PUTPIXEL()    ROP_OP(&d[0], col);        \
+                      ROP_OP(&d[1], (col >> 8)); \
+                      ROP_OP(&d[2], (col >> 16))
 #elif DEPTH == 32
-#define PUTPIXEL()    ROP_OP(((uint32_t *)d)[0], col)
+#define PUTPIXEL()    ROP_OP_32(((uint32_t *)&d[0]), col)
 #else
 #error unsupported DEPTH
 #endif