With the release of gcc 4.0 being only a few months away and people
already tring compiling with it, it's time for adding a compiler-gcc4.h .
This patch contains the following changes:
- compiler-gcc+.h: add the missing noinline and __compiler_offsetof
- compiler-gcc4.h: new file based on the corrected compiler-gcc+.h
- compiler.h: include compiler-gcc4.h for gcc 4
- compiler-gcc3.h: remove __compiler_offsetof (there will never be a
gcc 3.5)
small indention corrections
I've tested the compilation with both gcc 3.4.4 and a recent gcc 4.0
snapshot from Debian experimental.
Signed-off-by: Adrian Bunk <[email protected]>
---
include/linux/compiler-gcc+.h | 3 +++
include/linux/compiler-gcc3.h | 10 ++++------
include/linux/compiler-gcc4.h | 16 ++++++++++++++++
include/linux/compiler.h | 6 ++++--
4 files changed, 27 insertions(+), 8 deletions(-)
--- linux-2.6.11-rc2-mm2-full/include/linux/compiler.h.old 2005-01-30 09:59:28.000000000 +0100
+++ linux-2.6.11-rc2-mm2-full/include/linux/compiler.h 2005-01-30 10:00:15.000000000 +0100
@@ -34,8 +34,10 @@
#ifdef __KERNEL__
-#if __GNUC__ > 3
-# include <linux/compiler-gcc+.h> /* catch-all for GCC 4, 5, etc. */
+#if __GNUC__ > 4
+# include <linux/compiler-gcc+.h> /* catch-all for GCC 5, 6, etc. */
+#elif __GNUC__ == 4
+# include <linux/compiler-gcc4.h>
#elif __GNUC__ == 3
# include <linux/compiler-gcc3.h>
#elif __GNUC__ == 2
--- linux-2.6.11-rc2-mm2-full/include/linux/compiler-gcc+.h.old 2005-01-30 10:01:40.000000000 +0100
+++ linux-2.6.11-rc2-mm2-full/include/linux/compiler-gcc+.h 2005-01-30 10:09:01.000000000 +0100
@@ -13,4 +13,7 @@
#define __attribute_used__ __attribute__((__used__))
#define __attribute_pure__ __attribute__((pure))
#define __attribute_const__ __attribute__((__const__))
+#define noinline __attribute__((noinline))
#define __must_check __attribute__((warn_unused_result))
+#define __compiler_offsetof(a,b) __builtin_offsetof(a,b)
+
--- linux-2.6.11-rc2-mm2-full/include/linux/compiler-gcc3.h.old 2005-01-30 10:05:16.000000000 +0100
+++ linux-2.6.11-rc2-mm2-full/include/linux/compiler-gcc3.h 2005-01-30 10:08:38.000000000 +0100
@@ -10,7 +10,7 @@
#endif
#if __GNUC_MINOR__ > 0
-# define __deprecated __attribute__((deprecated))
+# define __deprecated __attribute__((deprecated))
#endif
#if __GNUC_MINOR__ >= 3
@@ -23,12 +23,10 @@
#define __attribute_const__ __attribute__((__const__))
#if __GNUC_MINOR__ >= 1
-#define noinline __attribute__((noinline))
+#define noinline __attribute__((noinline))
#endif
+
#if __GNUC_MINOR__ >= 4
-#define __must_check __attribute__((warn_unused_result))
+#define __must_check __attribute__((warn_unused_result))
#endif
-#if __GNUC_MINOR__ >= 5
-#define __compiler_offsetof(a,b) __builtin_offsetof(a,b)
-#endif
--- /dev/null 2004-11-25 03:16:25.000000000 +0100
+++ linux-2.6.11-rc2-mm2-full/include/linux/compiler-gcc4.h 2005-01-30 10:09:08.000000000 +0100
@@ -0,0 +1,16 @@
+/* Never include this file directly. Include <linux/compiler.h> instead. */
+
+/* These definitions are for GCC v4.x. */
+#include <linux/compiler-gcc.h>
+
+#define inline inline __attribute__((always_inline))
+#define __inline__ __inline__ __attribute__((always_inline))
+#define __inline __inline __attribute__((always_inline))
+#define __deprecated __attribute__((deprecated))
+#define __attribute_used__ __attribute__((__used__))
+#define __attribute_pure__ __attribute__((pure))
+#define __attribute_const__ __attribute__((__const__))
+#define noinline __attribute__((noinline))
+#define __must_check __attribute__((warn_unused_result))
+#define __compiler_offsetof(a,b) __builtin_offsetof(a,b)
+
Adrian Bunk <[email protected]> writes:
> With the release of gcc 4.0 being only a few months away and people
> already tring compiling with it, it's time for adding a compiler-gcc4.h .
>
> This patch contains the following changes:
> - compiler-gcc+.h: add the missing noinline and __compiler_offsetof
> - compiler-gcc4.h: new file based on the corrected compiler-gcc+.h
> - compiler.h: include compiler-gcc4.h for gcc 4
> - compiler-gcc3.h: remove __compiler_offsetof (there will never be a
> gcc 3.5)
> small indention corrections
I don't think it makes much sense right now because it's basically
identical to compiler-gcc3.h. I would only add it where there is a
need for a real difference.
-Andi
On Sun, Jan 30, 2005 at 03:11:19PM +0100, Andi Kleen wrote:
> Adrian Bunk <[email protected]> writes:
>
> > With the release of gcc 4.0 being only a few months away and people
> > already tring compiling with it, it's time for adding a compiler-gcc4.h .
> >
> > This patch contains the following changes:
> > - compiler-gcc+.h: add the missing noinline and __compiler_offsetof
> > - compiler-gcc4.h: new file based on the corrected compiler-gcc+.h
> > - compiler.h: include compiler-gcc4.h for gcc 4
> > - compiler-gcc3.h: remove __compiler_offsetof (there will never be a
> > gcc 3.5)
> > small indention corrections
>
> I don't think it makes much sense right now because it's basically
> identical to compiler-gcc3.h. I would only add it where there is a
> need for a real difference.
The currently used file for gcc 4 is compiler-gcc+.h, not
compiler-gcc3.h .
> -Andi
cu
Adrian
--
"Is there not promise of rain?" Ling Tan asked suddenly out
of the darkness. There had been need of rain for many days.
"Only a promise," Lao Er said.
Pearl S. Buck - Dragon Seed
Andi Kleen wrote:
>Adrian Bunk <[email protected]> writes:
>
>
>
>>With the release of gcc 4.0 being only a few months away and people
>>already tring compiling with it, it's time for adding a compiler-gcc4.h .
>>
>>This patch contains the following changes:
>>- compiler-gcc+.h: add the missing noinline and __compiler_offsetof
>>- compiler-gcc4.h: new file based on the corrected compiler-gcc+.h
>>- compiler.h: include compiler-gcc4.h for gcc 4
>>- compiler-gcc3.h: remove __compiler_offsetof (there will never be a
>> gcc 3.5)
>> small indention corrections
>>
>>
>
>I don't think it makes much sense right now because it's basically
>identical to compiler-gcc3.h. I would only add it where there is a
>need for a real difference.
>
>-Andi
>-
>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/
>
>
>
Hi!
But maybe gcc 4 will get different later, so I think this patch makes sense.
Matthias-Christian Ott
Followup to: <[email protected]>
By author: Matthias-Christian Ott <[email protected]>
In newsgroup: linux.dev.kernel
>
> Hi!
> But maybe gcc 4 will get different later, so I think this patch makes sense.
>
No, it doesn't. You fork when you have a reason. Eager forking is
*BAD*.
-hpa
On Thu, Feb 03, 2005 at 01:04:46AM +0000, H. Peter Anvin wrote:
> Followup to: <[email protected]>
> By author: Matthias-Christian Ott <[email protected]>
> In newsgroup: linux.dev.kernel
> >
> > Hi!
> > But maybe gcc 4 will get different later, so I think this patch makes sense.
> >
>
> No, it doesn't. You fork when you have a reason. Eager forking is
> *BAD*.
As I already said in this thread:
The currently used file for gcc 4 is compiler-gcc+.h, not
compiler-gcc3.h .
And the current setup is to have one file for every major number of gcc.
I have no strong opinion whether this approach or the approach of one
file for all gcc versions is better - but with the current approach,
everything else than a separate file for gcc 4 wasn't logical.
I can offer the following choices:
- please apply this compiler-gcc4.h patch
- let me send a patch merging all compiler-gcc*.h files into one
compiler-gcc.h file
- let me send a patch merging all compiler-gcc*.h files back into
compiler.h
> -hpa
cu
Adrian
--
"Is there not promise of rain?" Ling Tan asked suddenly out
of the darkness. There had been need of rain for many days.
"Only a promise," Lao Er said.
Pearl S. Buck - Dragon Seed
Adrian Bunk wrote:
>
> As I already said in this thread:
> The currently used file for gcc 4 is compiler-gcc+.h, not
> compiler-gcc3.h .
>
> And the current setup is to have one file for every major number of gcc.
> I have no strong opinion whether this approach or the approach of one
> file for all gcc versions is better - but with the current approach,
> everything else than a separate file for gcc 4 wasn't logical.
Yes it is. It's perfectly logical: gcc+ contains the "going forward"
version, and until it supports some feature that isn't in all versions
of gcc4, it's the right thing to do.
> I can offer the following choices:
> - please apply this compiler-gcc4.h patch
> - let me send a patch merging all compiler-gcc*.h files into one
> compiler-gcc.h file
> - let me send a patch merging all compiler-gcc*.h files back into
> compiler.h
No. Leave it the way it currently is until there is a *reason* to fork
a gcc4 module.
This isn't a cleanup you're proposing, it's a mess-up.
-hpa
On Sat, Feb 05, 2005 at 10:45:52AM -0800, H. Peter Anvin wrote:
> Adrian Bunk wrote:
> >
> >As I already said in this thread:
> > The currently used file for gcc 4 is compiler-gcc+.h, not
> > compiler-gcc3.h .
> >
> >And the current setup is to have one file for every major number of gcc.
> >I have no strong opinion whether this approach or the approach of one
> >file for all gcc versions is better - but with the current approach,
> >everything else than a separate file for gcc 4 wasn't logical.
>
> Yes it is. It's perfectly logical: gcc+ contains the "going forward"
> version, and until it supports some feature that isn't in all versions
> of gcc4, it's the right thing to do.
>...
It doesn't seem to be logical for everyone whether compiler-gcc+.h or
compiler-gcc3.h is used for gcc 4.0 ...
Perhaps compiler-gcc+.h (which wasn't always updated when
compiler-gcc3.h was updated) should be removed?
> -hpa
cu
Adrian
--
"Is there not promise of rain?" Ling Tan asked suddenly out
of the darkness. There had been need of rain for many days.
"Only a promise," Lao Er said.
Pearl S. Buck - Dragon Seed
Adrian Bunk wrote:
>
> It doesn't seem to be logical for everyone whether compiler-gcc+.h or
> compiler-gcc3.h is used for gcc 4.0 ...
>
> Perhaps compiler-gcc+.h (which wasn't always updated when
> compiler-gcc3.h was updated) should be removed?
>
That would make more sense. After all, gcc5+ can use the gcc4 file
until a gcc5 file proper is created.
-hpa
I set up a sample patch to clean up and merge the compiler.h files, on
the
basis that it's generally easier to manage all implementations of a
single
compiler feature in the same file right next to each other, instead of
spread across 3 files. This also cleans it up and puts the __KERNEL__
stuff in a single small section at the bottom, so as not to pollute the
user-space namespace. This is also a precursor to several other patches
I'm working on to clean up and split out user-space available ABI from
the kernel headers in include/linux to include/linux-abi.
A sample new GCC feature test:
/*
* __attribute__((__someattr__)) [GCC 3.3 or later]
* This will force the specified function to be inlined, or throw an
* error if inlining is impossible. This is designed to be used
* where inlining is critical. In the kernel, we want basically
* everything marked "inline" to be forced to inline, because
otherwise
* the code is just plain wrong.
*/
#if (__GNUC__ > 3) || (__GNUC__ == 3 && __GNUC_MINOR__ >= 3)
# define __attribute_someattr__ __attribute__((__someattr__))
#else
# define __attribute_someattr__ /* unimplemented */
#endif
Signed-off-by: Kyle Moffett <[email protected]>
Index: linux-2.5/include/linux/compiler-gcc+.h
diff -u linux-2.5/include/linux/compiler-gcc+.h:1.5
linux-2.5/include/linux/compiler-gcc+.h:removed
--- linux-2.5/include/linux/compiler-gcc+.h:1.5 Mon Aug 23 15:45:33 2004
+++ linux-2.5/include/linux/compiler-gcc+.h Sat Feb 5 19:07:42 2005
@@ -1,16 +0,0 @@
-/* Never include this file directly. Include <linux/compiler.h>
instead. */
-
-/*
- * These definitions are for Ueber-GCC: always newer than the latest
- * version and hence sporting everything plus a kitchen-sink.
- */
-#include <linux/compiler-gcc.h>
-
-#define inline inline __attribute__((always_inline))
-#define __inline__ __inline__ __attribute__((always_inline))
-#define __inline __inline __attribute__((always_inline))
-#define __deprecated __attribute__((deprecated))
-#define __attribute_used__ __attribute__((__used__))
-#define __attribute_pure__ __attribute__((pure))
-#define __attribute_const__ __attribute__((__const__))
-#define __must_check __attribute__((warn_unused_result))
Index: linux-2.5/include/linux/compiler-gcc.h
diff -u linux-2.5/include/linux/compiler-gcc.h:1.2
linux-2.5/include/linux/compiler-gcc.h:removed
--- linux-2.5/include/linux/compiler-gcc.h:1.2 Sun Sep 21 18:36:53 2003
+++ linux-2.5/include/linux/compiler-gcc.h Sat Feb 5 19:08:02 2005
@@ -1,17 +0,0 @@
-/* Never include this file directly. Include <linux/compiler.h>
instead. */
-
-/*
- * Common definitions for all gcc versions go here.
- */
-
-
-/* Optimization barrier */
-/* The "volatile" is due to gcc bugs */
-#define barrier() __asm__ __volatile__("": : :"memory")
-
-/* 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) \
- ({ unsigned long __ptr; \
- __asm__ ("" : "=g"(__ptr) : "0"(ptr)); \
- (typeof(ptr)) (__ptr + (off)); })
Index: linux-2.5/include/linux/compiler-gcc2.h
diff -u linux-2.5/include/linux/compiler-gcc2.h:1.3
linux-2.5/include/linux/compiler-gcc2.h:removed
--- linux-2.5/include/linux/compiler-gcc2.h:1.3 Mon Jan 19 13:43:54 2004
+++ linux-2.5/include/linux/compiler-gcc2.h Sat Feb 5 19:08:12 2005
@@ -1,24 +0,0 @@
-/* Never include this file directly. Include <linux/compiler.h>
instead. */
-
-/* These definitions are for GCC v2.x. */
-
-/* Somewhere in the middle of the GCC 2.96 development cycle, we
implemented
- a mechanism by which the user can annotate likely branch directions
and
- expect the blocks to be reordered appropriately. Define
__builtin_expect
- to nothing for earlier compilers. */
-#include <linux/compiler-gcc.h>
-
-#if __GNUC_MINOR__ < 96
-# define __builtin_expect(x, expected_value) (x)
-#endif
-
-#define __attribute_used__ __attribute__((__unused__))
-
-/*
- * The attribute `pure' is not implemented in GCC versions earlier
- * than 2.96.
- */
-#if __GNUC_MINOR__ >= 96
-# define __attribute_pure__ __attribute__((pure))
-# define __attribute_const__ __attribute__((__const__))
-#endif
Index: linux-2.5/include/linux/compiler-gcc3.h
diff -u linux-2.5/include/linux/compiler-gcc3.h:1.10
linux-2.5/include/linux/compiler-gcc3.h:removed
--- linux-2.5/include/linux/compiler-gcc3.h:1.10 Wed Sep 8 11:00:28
2004
+++ linux-2.5/include/linux/compiler-gcc3.h Sat Feb 5 19:08:25 2005
@@ -1,34 +0,0 @@
-/* Never include this file directly. Include <linux/compiler.h>
instead. */
-
-/* These definitions are for GCC v3.x. */
-#include <linux/compiler-gcc.h>
-
-#if __GNUC_MINOR__ >= 1
-# define inline inline __attribute__((always_inline))
-# define __inline__ __inline__ __attribute__((always_inline))
-# define __inline __inline __attribute__((always_inline))
-#endif
-
-#if __GNUC_MINOR__ > 0
-# define __deprecated __attribute__((deprecated))
-#endif
-
-#if __GNUC_MINOR__ >= 3
-# define __attribute_used__ __attribute__((__used__))
-#else
-# define __attribute_used__ __attribute__((__unused__))
-#endif
-
-#define __attribute_pure__ __attribute__((pure))
-#define __attribute_const__ __attribute__((__const__))
-
-#if __GNUC_MINOR__ >= 1
-#define noinline __attribute__((noinline))
-#endif
-#if __GNUC_MINOR__ >= 4
-#define __must_check __attribute__((warn_unused_result))
-#endif
-
-#if __GNUC_MINOR__ >= 5
-#define __compiler_offsetof(a,b) __builtin_offsetof(a,b)
-#endif
Index: linux-2.5/include/linux/compiler-intel.h
diff -u linux-2.5/include/linux/compiler-intel.h:1.2
linux-2.5/include/linux/compiler-intel.h:removed
--- linux-2.5/include/linux/compiler-intel.h:1.2 Sun Sep 21 18:36:53
2003
+++ linux-2.5/include/linux/compiler-intel.h Sat Feb 5 19:08:37 2005
@@ -1,24 +0,0 @@
-/* Never include this file directly. Include <linux/compiler.h>
instead. */
-
-#ifdef __ECC
-
-/* Some compiler specific definitions are overwritten here
- * for Intel ECC compiler
- */
-
-#include <asm/intrinsics.h>
-
-/* Intel ECC compiler doesn't support gcc specific asm stmts.
- * It uses intrinsics to do the equivalent things.
- */
-#undef barrier
-#undef RELOC_HIDE
-
-#define barrier() __memory_barrier()
-
-#define RELOC_HIDE(ptr, off) \
- ({ unsigned long __ptr; \
- __ptr = (unsigned long) (ptr); \
- (typeof(ptr)) (__ptr + (off)); })
-
-#endif
Index: linux-2.5/include/linux/compiler.h
diff -u linux-2.5/include/linux/compiler.h:1.38
linux-2.5/include/linux/compiler.h:1.39
--- linux-2.5/include/linux/compiler.h:1.38 Sat Oct 30 23:02:00 2004
+++ linux-2.5/include/linux/compiler.h Sat Feb 5 19:06:05 2005
@@ -1,148 +1,246 @@
#ifndef __LINUX_COMPILER_H
-#define __LINUX_COMPILER_H
-
+#define __LINUX_COMPILER_H 1
#ifndef __ASSEMBLY__
+/* sparse "compile" */
#ifdef __CHECKER__
-# define __user __attribute__((noderef, address_space(1)))
-# define __kernel /* default address space */
# define __safe __attribute__((safe))
# define __force __attribute__((force))
-# define __iomem __attribute__((noderef, address_space(2)))
# define __acquires(x) __attribute__((context(0,1)))
# define __releases(x) __attribute__((context(1,0)))
# define __acquire(x) __context__(1)
# define __release(x) __context__(-1)
-# define __cond_lock(x) ((x) ? ({ __context__(1); 1; }) : 0)
-extern void __chk_user_ptr(void __user *);
-extern void __chk_io_ptr(void __iomem *);
+# define __cond_lock(x) ((x) ? ({ __context__(1); 1; }) : 0 )
+# ifdef __KERNEL__
+# define __kernel /* default address space */
+# define __user __attribute__((noderef, address_space(1)))
+# define __iomem __attribute__((noderef, address_space(2)))
+# else
+# undef __kernel
+# define __user /* default address space */
+# undef __iomem
+# endif
+
+/* normal compile */
#else
-# define __user
-# define __kernel
+# define __builtin_warning(x, y...) (1)
# define __safe
# define __force
-# define __iomem
-# define __chk_user_ptr(x) (void)0
-# define __chk_io_ptr(x) (void)0
-# define __builtin_warning(x, y...) (1)
# define __acquires(x)
# define __releases(x)
# define __acquire(x) (void)0
# define __release(x) (void)0
-# define __cond_lock(x) (x)
+# define __cond_lock(x) ((x)?1:0)
+# ifdef __KERNEL__
+# define __kernel
+# define __user
+# define __iomem
+# else
+# undef __kernel
+# define __user
+# undef __iomem
+# endif
+#endif
+
+/* Basic address space checking */
+#ifdef __kernel
+static inline void __chk_kern_ptr (void __kernel *) {}
+#endif
+#ifdef __user
+static inline void __chk_user_ptr (void __user *) {}
+#endif
+#ifdef __iomem
+static inline void __chk_io_ptr (void __iomem *) {}
#endif
-#ifdef __KERNEL__
-#if __GNUC__ > 3
-# include <linux/compiler-gcc+.h> /* catch-all for GCC 4, 5, etc. */
-#elif __GNUC__ == 3
-# include <linux/compiler-gcc3.h>
-#elif __GNUC__ == 2
-# include <linux/compiler-gcc2.h>
+
+/***************************
+ * Generic Compiler Checks *
+ ***************************/
+
+#if defined(__INTEL_COMPILER) && defined(__ECC)
+ /* Intel uses compiler intrinsics instead of inline asm */
+# include <asm/intrinsics.h>
+# define __ptr_obfusc(dst,src) (void)( (dst) = (unsigned long)(src) )
+#elif __GNUC__ >= 2
+# define __memory_barrier() __asm__ __volatile__("": : :"memory")
+# define __ptr_obfusc(dst,src) __asm__("" : "=g"(__ptr) : "0"(ptr))
#else
-# error Sorry, your compiler is too old/not recognized.
+# error "Unknown compiler! Your compiler is either too old or not"
+# error "supported. If you are willing to provide patches to make"
+# error "linux compile on your system and maintain them, then please"
+# error "post them to the LKML <[email protected]>"
#endif
-/* Intel compiler defines __GNUC__. So we will overwrite
implementations
- * coming from above header files here
+
+
+/***************************
+ * Compiler Feature Checks *
+ ***************************/
+
+/*
+ * __builtin_expect(value,expected) [GCC 2.96 or later]
+ * This tells the compiler to optimize branching to favor one case
over
+ * another. This may reorder the branches or insert branch
prediction
+ * instructions.
*/
-#ifdef __INTEL_COMPILER
-# include <linux/compiler-intel.h>
+#if (__GNUC__ > 2) || (__GNUC__ == 2 && __GNUC_MINOR__ >= 96)
+# define __expect(value,expected) __builtin_expect(value,expected)
+#else
+# define __expect(value,expected) (value)
#endif
/*
- * Generic compiler-dependent macros required for kernel
- * build go below this comment. Actual compiler/compiler version
- * specific implementations come from the above header files
+ * __attribute__((__unused__)) [All supported compilers]
+ * This indicates that the corresponding variable or function is
known
+ * to be unused, therefore no warning should be emitted and the
variable
+ * or function may be omitted while optimizing.
*/
+#define __attribute_unused__ __attribute__((__unused__))
-#define likely(x) __builtin_expect(!!(x), 1)
-#define unlikely(x) __builtin_expect(!!(x), 0)
-
-/* Optimization barrier */
-#ifndef barrier
-# define barrier() __memory_barrier()
+/*
+ * __attribute__((__used__)) [GCC 3.3 or later]
+ * This indicates that the corresponding variable or function is
known
+ * to be used, despite appearances (possibly by inline assembly), and
+ * therefore it _must_ be emitted. This also quiets related warnings
+ * about that variable or function.
+ *
+ * NOTE: GCC prior to 3.3 did not omit data, so the only need for
this
+ * there is to quiet the warning, in which case it behaves exactly
the
+ * same as __attribute__((__unused__)).
+ */
+#if (__GNUC__ > 3) || (__GNUC__ == 3 && __GNUC_MINOR__ >= 3)
+# define __attribute_used__ __attribute__((__used__))
+#else
+# define __attribute_used__ __attribute_unused__
#endif
-#ifndef RELOC_HIDE
-# define RELOC_HIDE(ptr, off) \
- ({ unsigned long __ptr; \
- __ptr = (unsigned long) (ptr); \
- (typeof(ptr)) (__ptr + (off)); })
+/*
+ * __attribute__((__pure__)) [GCC 2.96 or later]
+ * From the GCC manual:
+ * Many functions have no effects except the return value and their
+ * return value depends only on the parameters and/or global
+ * variables. Such a function can be subject to common
subexpression
+ * elimination and loop optimization just as an arithmetic operator
+ * would be.
+ */
+#if (__GNUC__ > 2) || (__GNUC__ == 2 && __GNUC_MINOR__ >= 96)
+# define __attribute_pure__ __attribute__((__pure__))
+#else
+# define __attribute_pure__ /* unimplemented */
#endif
-#endif /* __ASSEMBLY__ */
-
-#endif /* __KERNEL__ */
-
/*
- * Allow us to mark functions as 'deprecated' and have gcc emit a nice
- * warning for each use, in hopes of speeding the functions removal.
- * Usage is:
- * int __deprecated foo(void)
+ * __attribute__((__const__)) [GCC 2.96 or later]
+ * From the GCC manual:
+ * 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.
+ *
+ * Note that a function that has pointer arguments and examines the
+ * data pointed to must _not_ be declared `const'. Likewise, a
+ * function that calls a non-`const' function usually must not be
+ * `const'. It does not make sense for a `const' function to
return
+ * `void'.
*/
-#ifndef __deprecated
-# define __deprecated /* unimplemented */
+#if (__GNUC__ > 2) || (__GNUC__ == 2 && __GNUC_MINOR__ >= 96)
+# define __attribute_pure__ __attribute__((__pure__))
+#else
+# define __attribute_pure__ /* unimplemented */
#endif
-#ifndef __must_check
-#define __must_check
+/*
+ * __attribute__((__always_inline__)) [GCC 3.1 or later]
+ * This will force the specified function to be inlined, or throw an
+ * error if inlining is impossible. This is designed to be used
+ * where inlining is critical. In the kernel, we want basically
+ * everything marked "inline" to be forced to inline, because
otherwise
+ * the code is just plain wrong.
+ */
+#if (__GNUC__ > 3) || (__GNUC__ == 3 && __GNUC_MINOR__ >= 1)
+# define __attribute_always_inline__ __attribute__((__always_inline__))
+#else
+# define __attribute_always_inline__ inline
#endif
/*
- * Allow us to avoid 'defined but not used' warnings on functions and
data,
- * as well as force them to be emitted to the assembly file.
- *
- * As of gcc 3.3, static functions that are not marked with
attribute((used))
- * may be elided from the assembly file. As of gcc 3.3, static data
not so
- * marked will not be elided, but this may change in a future gcc
version.
- *
- * In prior versions of gcc, such functions and data would be emitted,
but
- * would be warned about except with attribute((unused)).
+ * __attribute__((__noinline__)) [GCC 3.1 or later]
+ * This will force the specified function remain uninlined. This is
+ * designed to be used where inlining would cause errors, such as in
+ * certain places in the kernel.
*/
-#ifndef __attribute_used__
-# define __attribute_used__ /* unimplemented */
+#if (__GNUC__ > 3) || (__GNUC__ == 3 && __GNUC_MINOR__ >= 1)
+# define __attribute_noinline__ __attribute__((__noinline__))
+#else
+# define __attribute_noinline__ /* unimplemented */
#endif
/*
- * From the GCC manual:
- *
- * Many functions have no effects except the return value and their
- * return value depends only on the parameters and/or global
- * variables. Such a function can be subject to common subexpression
- * elimination and loop optimization just as an arithmetic operator
- * would be.
- * [...]
+ * __attribute__((__deprecated__)) [GCC 3.1 or later]
+ * This will cause the compiler to emit warnings whenever the
function
+ * or variable is used in non-deprecated code. This should be used
+ * whenever code is to be removed soon and we want to convert away
all
+ * old users of it.
*/
-#ifndef __attribute_pure__
-# define __attribute_pure__ /* unimplemented */
+#if (__GNUC__ > 3) || (__GNUC__ == 3 && __GNUC_MINOR__ >= 1)
+# define __attribute_deprecated__ __attribute__((__deprecated__))
+#else
+# define __attribute_deprecated__ /* unimplemented */
#endif
/*
- * From the GCC manual:
- *
- * 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.
- *
- * Note that a function that has pointer arguments and examines the
- * data pointed to must _not_ be declared `const'. Likewise, a
- * function that calls a non-`const' function usually must not be
- * `const'. It does not make sense for a `const' function to return
- * `void'.
+ * __attribute__((__warn_unused_result__)) [GCC 3.4 or later]
+ * This will cause the compiler to emit warnings whenever the
function
+ * is used without its return value being checked or used. This is
+ * used to warn about unchecked error conditions in the kernel.
*/
-#ifndef __attribute_const__
-# define __attribute_const__ /* unimplemented */
+#if (__GNUC__ > 3) || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)
+# define __attribute_warn_unused_result__
__attribute__((__warn_unused_result__))
+#else
+# define __attribute_warn_unused_result__ /* unimplemented */
#endif
-#ifndef noinline
-#define noinline
+/*
+ * __builtin_offsetof [GCC 3.5 or later]
+ * This returns the offset of a particular member in a given type
+ */
+#if (__GNUC__ > 3) || (__GNUC__ == 3 && __GNUC_MINOR__ >= 5)
+# define __offsetof(type,member) __builtin_offsetof(type,member)
+#else
+# define __offsetof(type,member) ((unsigned long) &((type *)0)->member)
#endif
-#ifndef __always_inline
-#define __always_inline inline
-#endif
+/* Stuff only used by the linux kernel, including short names */
+#ifdef __KERNEL__
+
+/* Memory barrier */
+# define barrier() __memory_barrier()
+
+/* This macro obfuscates arithmetic on a variable address so the
compiler
+ shouldn't recognize the original var and make assumptions about it
*/
+# define RELOC_HIDE(ptr,off) ({ \
+ unsigned long __ptr; \
+ __pointer_obfusc(__ptr,ptr); \
+ (typeof(ptr)) (__ptr + (off)); \
+})
+
+/* These help optimize branch-prediction for the fast-paths */
+# define likely(x) __builtin_expect(!!(x), 1)
+# define unlikely(x) __builtin_expect(!!(x), 0)
+
+#define noinline __attribute_noinline__
+#define __always_inline __attribute_always_inline__
+#define __deprecated __attribute_deprecated__
+#define __must_check __attribute_warn_unused_result__
+#define inline inline __attribute_always_inline__
+#define __inline __inline __attribute_always_inline__
+#define __inline__ __inline__ __attribute_always_inline__
+#define offsetof(a,b) __offsetof(a,b)
+
+#endif /* __KERNEL__ */
+
+#endif /* not __ASSEMBLY__ */
+#endif /* not __LINUX_COMPILER_H */
-#endif /* __LINUX_COMPILER_H */
Index: linux-2.5/include/linux/stddef.h
diff -u linux-2.5/include/linux/stddef.h:1.3
linux-2.5/include/linux/stddef.h:1.4
--- linux-2.5/include/linux/stddef.h:1.3 Wed Sep 8 11:00:28 2004
+++ linux-2.5/include/linux/stddef.h Sat Feb 5 19:06:05 2005
@@ -10,11 +10,4 @@
#define NULL ((void *)0)
#endif
-#undef offsetof
-#ifdef __compiler_offsetof
-#define offsetof(TYPE,MEMBER) __compiler_offsetof(TYPE,MEMBER)
-#else
-#define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
-#endif
-
#endif
Cheers,
Kyle Moffett
-----BEGIN GEEK CODE BLOCK-----
Version: 3.12
GCM/CS/IT/U d- s++: a18 C++++>$ UB/L/X/*++++(+)>$ P+++(++++)>$
L++++(+++) E W++(+) N+++(++) o? K? w--- O? M++ V? PS+() PE+(-) Y+
PGP+++ t+(+++) 5 X R? tv-(--) b++++(++) DI+ D+ G e->++++$ h!*()>++$ r
!y?(-)
------END GEEK CODE BLOCK------
On Sat, Feb 05, 2005 at 11:52:00AM -0800, H. Peter Anvin wrote:
> Adrian Bunk wrote:
> >
> >It doesn't seem to be logical for everyone whether compiler-gcc+.h or
> >compiler-gcc3.h is used for gcc 4.0 ...
> >
> >Perhaps compiler-gcc+.h (which wasn't always updated when
> >compiler-gcc3.h was updated) should be removed?
> >
>
> That would make more sense. After all, gcc5+ can use the gcc4 file
> until a gcc5 file proper is created.
The compiler-gcc*.h files check only for __GNUC_MINOR__ but not for
__GNUC__ .
Is the patch below OK?
> -hpa
cu
Adrian
<-- snip -->
With the release of gcc 4.0 being only a few months away and people
already tring compiling with it, it's time for adding a compiler-gcc4.h .
This patch contains the following changes:
- remove compiler-gcc+.h
- compiler-gcc4.h: new file based on a corrected compiler-gcc+.h
- compiler.h: include compiler-gcc4.h for gcc 4
- compiler.h: #error for gcc > 4
- compiler-gcc3.h: remove __compiler_offsetof (there will never be a
gcc 3.5)
small indention corrections
I've tested the compilation with both gcc 3.4.4 and a recent gcc 4.0
snapshot from Debian experimental.
Signed-off-by: Adrian Bunk <[email protected]>
---
include/linux/compiler-gcc+.h | 3 +++
include/linux/compiler-gcc3.h | 10 ++++------
include/linux/compiler-gcc4.h | 16 ++++++++++++++++
include/linux/compiler.h | 6 ++++--
4 files changed, 27 insertions(+), 8 deletions(-)
--- linux-2.6.11-rc2-mm2-full/include/linux/compiler.h.old 2005-01-30 09:59:28.000000000 +0100
+++ linux-2.6.11-rc2-mm2-full/include/linux/compiler.h 2005-01-30 10:00:15.000000000 +0100
@@ -34,8 +34,10 @@
#ifdef __KERNEL__
-#if __GNUC__ > 3
-# include <linux/compiler-gcc+.h> /* catch-all for GCC 4, 5, etc. */
+#if __GNUC__ > 4
+#error no compiler-gcc.h file for this gcc version
+#elif __GNUC__ == 4
+# include <linux/compiler-gcc4.h>
#elif __GNUC__ == 3
# include <linux/compiler-gcc3.h>
#elif __GNUC__ == 2
--- linux-2.6.11-rc2-mm2-full/include/linux/compiler-gcc3.h.old 2005-01-30 10:05:16.000000000 +0100
+++ linux-2.6.11-rc2-mm2-full/include/linux/compiler-gcc3.h 2005-01-30 10:08:38.000000000 +0100
@@ -10,7 +10,7 @@
#endif
#if __GNUC_MINOR__ > 0
-# define __deprecated __attribute__((deprecated))
+# define __deprecated __attribute__((deprecated))
#endif
#if __GNUC_MINOR__ >= 3
@@ -23,12 +23,10 @@
#define __attribute_const__ __attribute__((__const__))
#if __GNUC_MINOR__ >= 1
-#define noinline __attribute__((noinline))
+#define noinline __attribute__((noinline))
#endif
+
#if __GNUC_MINOR__ >= 4
-#define __must_check __attribute__((warn_unused_result))
+#define __must_check __attribute__((warn_unused_result))
#endif
-#if __GNUC_MINOR__ >= 5
-#define __compiler_offsetof(a,b) __builtin_offsetof(a,b)
-#endif
--- /dev/null 2004-11-25 03:16:25.000000000 +0100
+++ linux-2.6.11-rc2-mm2-full/include/linux/compiler-gcc4.h 2005-01-30 10:09:08.000000000 +0100
@@ -0,0 +1,16 @@
+/* Never include this file directly. Include <linux/compiler.h> instead. */
+
+/* These definitions are for GCC v4.x. */
+#include <linux/compiler-gcc.h>
+
+#define inline inline __attribute__((always_inline))
+#define __inline__ __inline__ __attribute__((always_inline))
+#define __inline __inline __attribute__((always_inline))
+#define __deprecated __attribute__((deprecated))
+#define __attribute_used__ __attribute__((__used__))
+#define __attribute_pure__ __attribute__((pure))
+#define __attribute_const__ __attribute__((__const__))
+#define noinline __attribute__((noinline))
+#define __must_check __attribute__((warn_unused_result))
+#define __compiler_offsetof(a,b) __builtin_offsetof(a,b)
+
--- linux-2.6.11-rc3-mm1-full/include/linux/compiler-gcc+.h 2004-12-24 22:35:39.000000000 +0100
+++ /dev/null 2004-11-25 03:16:25.000000000 +0100
@@ -1,16 +0,0 @@
-/* Never include this file directly. Include <linux/compiler.h> instead. */
-
-/*
- * These definitions are for Ueber-GCC: always newer than the latest
- * version and hence sporting everything plus a kitchen-sink.
- */
-#include <linux/compiler-gcc.h>
-
-#define inline inline __attribute__((always_inline))
-#define __inline__ __inline__ __attribute__((always_inline))
-#define __inline __inline __attribute__((always_inline))
-#define __deprecated __attribute__((deprecated))
-#define __attribute_used__ __attribute__((__used__))
-#define __attribute_pure__ __attribute__((pure))
-#define __attribute_const__ __attribute__((__const__))
-#define __must_check __attribute__((warn_unused_result))