Gcc info page:
`const'
Many functions do not examine any values except their arguments,
and have no effects except the return value. Basically this is
just slightly more strict class than the `pure' attribute above,
since function is not allowed to read global memory.
So, it seems byte swapping functions should be __attribute__((const))
Here is a patch:
replace obsolete __const__ qualifiers on function return type with
__attribute__((const)).
It also adds missing __attribute__((const)) for
include/asm-i386/byteorder.h:___arch__swab64()
Linus, please apply.
Nikita.
===== include/asm-arm/current.h 1.3 vs edited =====
--- 1.3/include/asm-arm/current.h Sat Dec 28 19:26:45 2002
+++ edited/include/asm-arm/current.h Mon Jun 2 14:44:24 2003
@@ -3,7 +3,7 @@
#include <linux/thread_info.h>
-static inline struct task_struct *get_current(void) __attribute__ (( __const__ ));
+static inline struct task_struct *get_current(void) __attribute_const;
static inline struct task_struct *get_current(void)
{
===== include/asm-arm/thread_info.h 1.6 vs edited =====
--- 1.6/include/asm-arm/thread_info.h Sat Dec 28 19:26:45 2002
+++ edited/include/asm-arm/thread_info.h Mon Jun 2 14:44:24 2003
@@ -74,7 +74,7 @@
/*
* how to get the thread information struct from C
*/
-static inline struct thread_info *current_thread_info(void) __attribute__ (( __const__ ));
+static inline struct thread_info *current_thread_info(void) __attribute_const;
static inline struct thread_info *current_thread_info(void)
{
===== include/asm-cris/byteorder.h 1.1 vs edited =====
--- 1.1/include/asm-cris/byteorder.h Tue Feb 5 20:56:43 2002
+++ edited/include/asm-cris/byteorder.h Mon Jun 2 14:44:24 2003
@@ -12,14 +12,14 @@
* them together into ntohl etc.
*/
-static __inline__ __const__ __u32 ___arch__swab32(__u32 x)
+static __inline__ __attribute_const __u32 ___arch__swab32(__u32 x)
{
__asm__ ("swapwb %0" : "=r" (x) : "0" (x));
return(x);
}
-static __inline__ __const__ __u16 ___arch__swab16(__u16 x)
+static __inline__ __attribute_const __u16 ___arch__swab16(__u16 x)
{
__asm__ ("swapb %0" : "=r" (x) : "0" (x));
===== include/asm-i386/byteorder.h 1.2 vs edited =====
--- 1.2/include/asm-i386/byteorder.h Fri Oct 11 21:15:35 2002
+++ edited/include/asm-i386/byteorder.h Mon Jun 2 14:40:24 2003
@@ -8,9 +8,10 @@
/* For avoiding bswap on i386 */
#ifdef __KERNEL__
#include <linux/config.h>
+#include <linux/compiler.h>
#endif
-static __inline__ __const__ __u32 ___arch__swab32(__u32 x)
+static __inline__ __attribute_const __u32 ___arch__swab32(__u32 x)
{
#ifdef CONFIG_X86_BSWAP
__asm__("bswap %0" : "=r" (x) : "0" (x));
@@ -26,7 +27,7 @@
/* gcc should generate this for open coded C now too. May be worth switching to
it because inline assembly cannot be scheduled. -AK */
-static __inline__ __const__ __u16 ___arch__swab16(__u16 x)
+static __inline__ __attribute_const __u16 ___arch__swab16(__u16 x)
{
__asm__("xchgb %b0,%h0" /* swap bytes */
: "=q" (x)
@@ -35,7 +36,7 @@
}
-static inline __u64 ___arch__swab64(__u64 val)
+static inline __attribute_const __u64 ___arch__swab64(__u64 val)
{
union {
struct { __u32 a,b; } s;
===== include/asm-ia64/byteorder.h 1.2 vs edited =====
--- 1.2/include/asm-ia64/byteorder.h Tue Feb 5 10:39:14 2002
+++ edited/include/asm-ia64/byteorder.h Mon Jun 2 14:44:24 2003
@@ -8,7 +8,7 @@
#include <asm/types.h>
-static __inline__ __const__ __u64
+static __inline__ __attribute_const __u64
__ia64_swab64 (__u64 x)
{
__u64 result;
@@ -17,13 +17,13 @@
return result;
}
-static __inline__ __const__ __u32
+static __inline__ __attribute_const __u32
__ia64_swab32 (__u32 x)
{
return __ia64_swab64(x) >> 32;
}
-static __inline__ __const__ __u16
+static __inline__ __attribute_const __u16
__ia64_swab16(__u16 x)
{
return __ia64_swab64(x) >> 48;
===== include/asm-m68k/byteorder.h 1.1 vs edited =====
--- 1.1/include/asm-m68k/byteorder.h Tue Feb 5 20:39:46 2002
+++ edited/include/asm-m68k/byteorder.h Mon Jun 2 14:44:24 2003
@@ -5,7 +5,7 @@
#ifdef __GNUC__
-static __inline__ __const__ __u32 ___arch__swab32(__u32 val)
+static __inline__ __attribute_const __u32 ___arch__swab32(__u32 val)
{
__asm__("rolw #8,%0; swap %0; rolw #8,%0" : "=d" (val) : "0" (val));
return val;
===== include/asm-parisc/byteorder.h 1.1 vs edited =====
--- 1.1/include/asm-parisc/byteorder.h Tue Feb 5 20:39:57 2002
+++ edited/include/asm-parisc/byteorder.h Mon Jun 2 14:44:24 2003
@@ -5,7 +5,7 @@
#ifdef __GNUC__
-static __inline__ __const__ __u32 ___arch__swab32(__u32 x)
+static __inline__ __attribute_const __u32 ___arch__swab32(__u32 x)
{
unsigned int temp;
__asm__("shd %0, %0, 16, %1\n\t" /* shift abcdabcd -> cdab */
@@ -28,7 +28,7 @@
** HSHR 67452301 -> *6*4*2*0 into %0
** OR %0 | %1 -> 76543210 into %0 (all done!)
*/
-static __inline__ __const__ __u64 ___arch__swab64(__u64 x) {
+static __inline__ __attribute_const __u64 ___arch__swab64(__u64 x) {
__u64 temp;
__asm__("permh 3210, %0, %0\n\t"
"hshl %0, 8, %1\n\t"
@@ -40,7 +40,7 @@
}
#define __arch__swab64(x) ___arch__swab64(x)
#else
-static __inline__ __const__ __u64 ___arch__swab64(__u64 x)
+static __inline__ __attribute_const __u64 ___arch__swab64(__u64 x)
{
__u32 t1 = (__u32) x;
__u32 t2 = (__u32) ((x) >> 32);
@@ -51,7 +51,7 @@
#endif
-static __inline__ __const__ __u16 ___arch__swab16(__u16 x)
+static __inline__ __attribute_const __u16 ___arch__swab16(__u16 x)
{
__asm__("dep %0, 15, 8, %0\n\t" /* deposit 00ab -> 0bab */
"shd %r0, %0, 8, %0" /* shift 000000ab -> 00ba */
===== include/asm-ppc/byteorder.h 1.5 vs edited =====
--- 1.5/include/asm-ppc/byteorder.h Mon Sep 16 08:52:03 2002
+++ edited/include/asm-ppc/byteorder.h Mon Jun 2 14:44:24 2003
@@ -32,7 +32,7 @@
__asm__ __volatile__ ("stwbrx %1,0,%2" : "=m" (*addr) : "r" (val), "r" (addr));
}
-static __inline__ __const__ __u16 ___arch__swab16(__u16 value)
+static __inline__ __attribute_const __u16 ___arch__swab16(__u16 value)
{
__u16 result;
@@ -40,7 +40,7 @@
return result;
}
-static __inline__ __const__ __u32 ___arch__swab32(__u32 value)
+static __inline__ __attribute_const __u32 ___arch__swab32(__u32 value)
{
__u32 result;
===== include/asm-ppc64/byteorder.h 1.1 vs edited =====
--- 1.1/include/asm-ppc64/byteorder.h Thu Feb 14 15:14:36 2002
+++ edited/include/asm-ppc64/byteorder.h Mon Jun 2 14:44:24 2003
@@ -40,7 +40,7 @@
}
#if 0
-static __inline__ __const__ __u16 ___arch__swab16(__u16 value)
+static __inline__ __attribute_const __u16 ___arch__swab16(__u16 value)
{
__u16 result;
@@ -50,7 +50,7 @@
return result;
}
-static __inline__ __const__ __u32 ___arch__swab32(__u32 value)
+static __inline__ __attribute_const __u32 ___arch__swab32(__u32 value)
{
__u32 result;
@@ -62,7 +62,7 @@
return result;
}
-static __inline__ __const__ __u64 ___arch__swab64(__u64 value)
+static __inline__ __attribute_const __u64 ___arch__swab64(__u64 value)
{
__u64 result;
#error implement me
===== include/asm-s390/byteorder.h 1.4 vs edited =====
--- 1.4/include/asm-s390/byteorder.h Mon Apr 14 23:11:58 2003
+++ edited/include/asm-s390/byteorder.h Mon Jun 2 14:44:24 2003
@@ -14,7 +14,7 @@
#ifdef __GNUC__
#ifdef __s390x__
-static __inline__ __const__ __u64 ___arch__swab64p(__u64 *x)
+static __inline__ __attribute_const __u64 ___arch__swab64p(__u64 *x)
{
__u64 result;
@@ -24,7 +24,7 @@
return result;
}
-static __inline__ __const__ __u64 ___arch__swab64(__u64 x)
+static __inline__ __attribute_const __u64 ___arch__swab64(__u64 x)
{
__u64 result;
@@ -40,7 +40,7 @@
}
#endif /* __s390x__ */
-static __inline__ __const__ __u32 ___arch__swab32p(__u32 *x)
+static __inline__ __attribute_const __u32 ___arch__swab32p(__u32 *x)
{
__u32 result;
@@ -58,7 +58,7 @@
return result;
}
-static __inline__ __const__ __u32 ___arch__swab32(__u32 x)
+static __inline__ __attribute_const __u32 ___arch__swab32(__u32 x)
{
#ifndef __s390x__
return ___arch__swab32p(&x);
@@ -77,7 +77,7 @@
*x = ___arch__swab32p(x);
}
-static __inline__ __const__ __u16 ___arch__swab16p(__u16 *x)
+static __inline__ __attribute_const __u16 ___arch__swab16p(__u16 *x)
{
__u16 result;
@@ -93,7 +93,7 @@
return result;
}
-static __inline__ __const__ __u16 ___arch__swab16(__u16 x)
+static __inline__ __attribute_const __u16 ___arch__swab16(__u16 x)
{
return ___arch__swab16p(&x);
}
===== include/asm-sh/byteorder.h 1.1 vs edited =====
--- 1.1/include/asm-sh/byteorder.h Tue Feb 5 20:39:53 2002
+++ edited/include/asm-sh/byteorder.h Mon Jun 2 14:44:24 2003
@@ -7,7 +7,7 @@
#include <asm/types.h>
-static __inline__ __const__ __u32 ___arch__swab32(__u32 x)
+static __inline__ __attribute_const __u32 ___arch__swab32(__u32 x)
{
__asm__("swap.b %0, %0\n\t"
"swap.w %0, %0\n\t"
@@ -17,7 +17,7 @@
return x;
}
-static __inline__ __const__ __u16 ___arch__swab16(__u16 x)
+static __inline__ __attribute_const __u16 ___arch__swab16(__u16 x)
{
__asm__("swap.b %0, %0"
: "=r" (x)
===== include/asm-v850/byteorder.h 1.1 vs edited =====
--- 1.1/include/asm-v850/byteorder.h Fri Nov 1 19:38:12 2002
+++ edited/include/asm-v850/byteorder.h Mon Jun 2 14:44:24 2003
@@ -18,14 +18,14 @@
#ifdef __GNUC__
-static __inline__ __const__ __u32 ___arch__swab32 (__u32 word)
+static __inline__ __attribute_const __u32 ___arch__swab32 (__u32 word)
{
__u32 res;
__asm__ ("bsw %1, %0" : "=r" (res) : "r" (word));
return res;
}
-static __inline__ __const__ __u16 ___arch__swab16 (__u16 half_word)
+static __inline__ __attribute_const __u16 ___arch__swab16 (__u16 half_word)
{
__u16 res;
__asm__ ("bsh %1, %0" : "=r" (res) : "r" (half_word));
===== include/asm-x86_64/byteorder.h 1.2 vs edited =====
--- 1.2/include/asm-x86_64/byteorder.h Fri Apr 4 02:51:08 2003
+++ edited/include/asm-x86_64/byteorder.h Mon Jun 2 14:44:24 2003
@@ -5,13 +5,13 @@
#ifdef __GNUC__
-static __inline__ __const__ __u64 ___arch__swab64(__u64 x)
+static __inline__ __attribute_const __u64 ___arch__swab64(__u64 x)
{
__asm__("bswapq %0" : "=r" (x) : "0" (x));
return x;
}
-static __inline__ __const__ __u32 ___arch__swab32(__u32 x)
+static __inline__ __attribute_const __u32 ___arch__swab32(__u32 x)
{
__asm__("bswapl %0" : "=r" (x) : "0" (x));
return x;
===== include/linux/compiler.h 1.15 vs edited =====
--- 1.15/include/linux/compiler.h Wed Apr 9 22:15:46 2003
+++ edited/include/linux/compiler.h Mon Jun 2 14:44:18 2003
@@ -56,6 +56,22 @@
#define __attribute_used__ __attribute__((__unused__))
#endif
+/* The attribute `pure' is not implemented in GCC versions earlier than 2.96. */
+#if (__GNUC__ > 2) || (__GNUC__ == 2 && __GNUC_MINOR__ >= 96)
+#define __attribute_pure __attribute__ ((__pure__))
+#else
+#define __attribute_pure
+#endif
+
+/* The attribute `const' is not implemented in GCC versions earlier than 2.5. */
+/* Basically this is just slightly more strict class than the `pure'
+ attribute */
+#if (__GNUC__ > 2) || (__GNUC__ == 2 && __GNUC_MINOR__ >= 5)
+#define __attribute_const __attribute__ ((__const__))
+#else
+#define __attribute_const
+#endif
+
/* This macro obfuscates arithmetic on a variable address so that gcc
shouldn't recognize the original var, and make assumptions about it */
#define RELOC_HIDE(ptr, off) \
===== include/linux/byteorder/swab.h 1.2 vs edited =====
--- 1.2/include/linux/byteorder/swab.h Tue Feb 5 10:43:00 2002
+++ edited/include/linux/byteorder/swab.h Fri May 30 17:34:25 2003
@@ -128,7 +128,7 @@
#endif /* OPTIMIZE */
-static __inline__ __const__ __u16 __fswab16(__u16 x)
+static __inline__ __attribute_const __u16 __fswab16(__u16 x)
{
return __arch__swab16(x);
}
@@ -141,7 +141,7 @@
__arch__swab16s(addr);
}
-static __inline__ __const__ __u32 __fswab32(__u32 x)
+static __inline__ __attribute_const __u32 __fswab32(__u32 x)
{
return __arch__swab32(x);
}
@@ -155,7 +155,7 @@
}
#ifdef __BYTEORDER_HAS_U64__
-static __inline__ __const__ __u64 __fswab64(__u64 x)
+static __inline__ __attribute_const __u64 __fswab64(__u64 x)
{
# ifdef __SWAB_64_THRU_32__
__u32 h = x >> 32;
===== include/linux/byteorder/swabb.h 1.2 vs edited =====
--- 1.2/include/linux/byteorder/swabb.h Tue Feb 5 10:43:00 2002
+++ edited/include/linux/byteorder/swabb.h Mon Jun 2 14:44:24 2003
@@ -92,7 +92,7 @@
#endif /* OPTIMIZE */
-static __inline__ __const__ __u32 __fswahw32(__u32 x)
+static __inline__ __attribute_const __u32 __fswahw32(__u32 x)
{
return __arch__swahw32(x);
}
@@ -106,7 +106,7 @@
}
-static __inline__ __const__ __u32 __fswahb32(__u32 x)
+static __inline__ __attribute_const __u32 __fswahb32(__u32 x)
{
return __arch__swahb32(x);
}
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/