Add a dummy offset to the arrays generated by genassym to avoid ary[0]

The dummy offset avoids the generation of dummy arrays of size zero.
This whole code path is a hack, but after a lot of messing around
Alex and I determined that it was easier to hack it then to try to
redo the code due to complications introduced by cross-compiled
environments.

Submitted-by: Alex Hornung <ahornung@gmail.com>

diff --git a/sys/sys/assym.h b/sys/sys/assym.h
index 8a1b7c3..3d9ecb4 100644 (file)
--- a/sys/sys/assym.h
+++ b/sys/sys/assym.h
@@ -36,13 +36,17 @@
 #error "This file should not be included by userland programs."
 #endif
 
-#define        ASSYM_ABS(value)        ((value) < 0 ? -((value) + 1) + 1ULL : (value))
+/* Add an ASSYM_BIAS to all arrays to avoid zero-size, which can be
+   mishandled in some compilers */
+#define ASSYM_BIAS              0x00100000
 
-#define        ASSYM(name, value)                                      \
-char name ## sign[(value) < 0 ? 1 : 0];                                \
-char name ## w0[ASSYM_ABS(value) & 0xFFFFU];                   \
-char name ## w1[(ASSYM_ABS(value) & 0xFFFF0000UL) >> 16];      \
-char name ## w2[(ASSYM_ABS(value) & 0xFFFF00000000ULL) >> 32]; \
-char name ## w3[(ASSYM_ABS(value) & 0xFFFF000000000000ULL) >> 48]
+#define ASSYM_ABS(value)        ((value) < 0 ? -((value) + 1) + 1ULL : (value))
+
+#define ASSYM(name, value)                                      \
+char name ## sign[((value) < 0 ? 1 : 0) + ASSYM_BIAS];                         \
+char name ## w0[(ASSYM_ABS(value) & 0xFFFFU) + ASSYM_BIAS];                    \
+char name ## w1[((ASSYM_ABS(value) & 0xFFFF0000UL) >> 16) + ASSYM_BIAS];       \
+char name ## w2[((ASSYM_ABS(value) & 0xFFFF00000000ULL) >> 32) + ASSYM_BIAS];  \
+char name ## w3[((ASSYM_ABS(value) & 0xFFFF000000000000ULL) >> 48) + ASSYM_BIAS]
 
 #endif /* !_SYS_ASSYM_H_ */