[Freeciv-Dev] (PR#4788) range checks in BV macros

["Jason Short" <jdorje@xxxxxxxxxxxxxxxxxxxxx>]

This patch introduces assertions on the range of the input in the BV_*** 
macros.  Probably a good thing IMO.

jason

Index: common/shared.h
===================================================================
RCS file: /home/freeciv/CVS/freeciv/common/shared.h,v
retrieving revision 1.114
diff -u -r1.114 shared.h
--- common/shared.h     2003/07/19 04:05:59     1.114
+++ common/shared.h     2003/08/08 04:20:50
@@ -120,12 +120,16 @@
 #define _BV_BYTES(bits)                ((((bits) - 1) / 8) + 1)
 #define _BV_BYTE_INDEX(bits)   ((bits) / 8)
 #define _BV_BITMASK(bit)       (1u << ((bit) & 0x7))
+#define _BV_ASSERT(bv, bit) assert((bit) >= 0 && (bit) < sizeof((bv).vec) * 8)
 #define BV_ISSET(bv, bit) \
-  (((bv).vec[_BV_BYTE_INDEX(bit)] & _BV_BITMASK(bit)) != 0)
+  (_BV_ASSERT(bv, bit), \
+   ((bv).vec[_BV_BYTE_INDEX(bit)] & _BV_BITMASK(bit)) != 0)
 #define BV_SET(bv, bit) \
-  do { (bv).vec[_BV_BYTE_INDEX(bit)] |= _BV_BITMASK(bit); } while(FALSE)
+  do { _BV_ASSERT(bv, bit); \
+       (bv).vec[_BV_BYTE_INDEX(bit)] |= _BV_BITMASK(bit); } while(FALSE)
 #define BV_CLR(bv, bit) \
-  do { (bv).vec[_BV_BYTE_INDEX(bit)] &= ~_BV_BITMASK(bit); } while(FALSE)
+  do { _BV_ASSERT(bv, bit); \
+       (bv).vec[_BV_BYTE_INDEX(bit)] &= ~_BV_BITMASK(bit); } while(FALSE)
 #define BV_CLR_ALL(bv) \
   do { memset((bv).vec, 0, sizeof((bv).vec)); } while(FALSE)
 bool bv_check_mask(unsigned char *vec1, unsigned char *vec2, size_t size1,