On Mar 11 2007 13:50, Rusty Russell wrote: >On Sat, 2007-03-10 at 02:04 +0100, Jan Engelhardt wrote: >> Getting back at the macro, how would you like to have it merged? > >Well, this is what I sent to Linus and Andrew (many thanks to those who >made appropriately whimsical *or* useful comments): > >diff -r 1ccdf46b0f41 include/linux/compiler-gcc.h >--- a/include/linux/compiler-gcc.h Sat Mar 10 09:55:29 2007 +1100 >+++ b/include/linux/compiler-gcc.h Sat Mar 10 11:06:35 2007 +1100 >@@ -22,6 +22,9 @@ > __asm__ ("" : "=r"(__ptr) : "0"(ptr)); \ > (typeof(ptr)) (__ptr + (off)); }) > >+/* &a[0] degrades to a pointer: a different type from an array */ >+#define __must_be_array(a) \ >+ BUILD_BUG_ON_ZERO(__builtin_types_compatible_p(typeof(a), typeof(&a[0])))
This looks _much_ nicer! (And BUILD_BUG_ON is also appropriately commented.) > > #define inline inline __attribute__((always_inline)) > #define __inline__ __inline__ __attribute__((always_inline)) >diff -r 1ccdf46b0f41 include/linux/compiler-intel.h >--- a/include/linux/compiler-intel.h Sat Mar 10 09:55:29 2007 +1100 >+++ b/include/linux/compiler-intel.h Sat Mar 10 11:06:25 2007 +1100 >@@ -21,4 +21,7 @@ > __ptr = (unsigned long) (ptr); \ > (typeof(ptr)) (__ptr + (off)); }) > >+/* Intel ECC compiler doesn't support __builtin_types_compatible_p() */ >+#define __must_be_array(a) 0 >+ > #endif >diff -r 1ccdf46b0f41 include/linux/kernel.h >--- a/include/linux/kernel.h Sat Mar 10 09:55:29 2007 +1100 >+++ b/include/linux/kernel.h Sat Mar 10 11:06:16 2007 +1100 >@@ -35,7 +35,8 @@ extern const char linux_proc_banner[]; > #define ALIGN(x,a) __ALIGN_MASK(x,(typeof(x))(a)-1) > #define __ALIGN_MASK(x,mask) (((x)+(mask))&~(mask)) > >-#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0])) >+#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + >__must_be_array(arr)) >+ > #define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f)) > #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d)) > #define roundup(x, y) ((((x) + ((y) - 1)) / (y)) * (y)) 80 cols *cough* :) Jan -- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/