July 30, 2018 I reported the following to linux-kernel, linux-alpha, etc.:
On an alpha system, got the following build error on the 4.18-rc7
mainline kernel source tree:
HOSTCC net/bpfilter/main.o
In file included from tools/include/uapi/asm/bitsperlong.h:17,
from /usr/include/asm-generic/int-ll64.h:12,
from /usr/include/alpha-linux-gnu/asm/types.h:24,
from tools/include/linux/types.h:10,
from ./include/uapi/linux/bpf.h:11,
from net/bpfilter/main.c:9:
tools/include/asm-generic/bitsperlong.h:14:2: error: #error Inconsistent word size. Check asm/bitsperlong.h
#error Inconsistent word size. Check asm/bitsperlong.h
^~~~~
scripts/Makefile.host:107: recipe for target 'net/bpfilter/main.o' failed
make[2]: *** [net/bpfilter/main.o] Error 1
scripts/Makefile.build:558: recipe for target 'net/bpfilter' failed
make[1]: *** [net/bpfilter] Error 2
Makefile:1029: recipe for target 'net' failed
make: *** [net] Error 2
I implemented a crap workaround at the time in
"linux/tools/include/asm-generic/bitsperlong.h", similar to what some
frustrated person did for the x86-64 case in
"linux/include/asm-generic/bitsperlong.h". Never sent that in because I
knew it was the wrong approach.
The proper fix is attached. If needed, consider this my official
"signed off by" and/or "tested by". This applies cleanly to at least
all kernel mainline source trees from 4.18 to current.
Thanks.
--Bob
--- a/tools/include/uapi/asm/bitsperlong.h 2019-01-20 14:40:32.522422998 -0600
+++ b/tools/include/uapi/asm/bitsperlong.h 2019-01-21 09:51:45.336938260 -0600
@@ -13,6 +13,8 @@
#include "../../arch/mips/include/uapi/asm/bitsperlong.h"
#elif defined(__ia64__)
#include "../../arch/ia64/include/uapi/asm/bitsperlong.h"
+#elif defined(__alpha__)
+#include "../../arch/alpha/include/uapi/asm/bitsperlong.h"
#else
#include <asm-generic/bitsperlong.h>
#endif
