[U-Boot] [PATCH v2 1/3] compiler_gcc: prevent redefining attributes

2014-09-18 Thread Jeroen Hofstee
The libc headers on FreeBSD and likely related projects as well contain an
header file, cdefs.h which provides similiar functionality as linux/compiler.h.
It provides compiler independent defines like __weak __packed, to allow
compiling with multiple compilers which might have a different syntax for such
extension.

Since that header file is included in multiple standard headers, like stddef.h
and stdarg.h, multiple definitions of those defines will be present if both are
included. When compiling u-boot the compiler will warn about it hundreds of
times since e.g. common.h will include both files indirectly.

commit 7ea50d52849fe8ffa5b5b74c979b60b1045d6fc9 compiler_gcc: do not redefine
__gnu_attributes prevented such redefinitions, but this was undone by commit
fb8ffd7cfc68b3dc44e182356a207d784cb30b34 compiler*.h: sync
include/linux/compiler*.h with Linux 3.16.

Add the checks back where necessary to prevent such warnings.

As the original patch this checkpatch warning is ignored:
WARNING: Adding new packed members is to be done with care

Cc: Masahiro Yamada yamad...@jp.panasonic.com
Cc: Tom Rini tr...@ti.com
Signed-off-by: Jeroen Hofstee jer...@myspectrum.nl
---
changes since v1:
  As requested by Masahiro, elaborate a bit about what cdefs.h is and how these
  warnings are caused. Only this patch is reposted.
---
 include/linux/compiler-gcc.h | 10 ++
 1 file changed, 10 insertions(+)

diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h
index 02ae99e..e057bd2 100644
--- a/include/linux/compiler-gcc.h
+++ b/include/linux/compiler-gcc.h
@@ -64,8 +64,12 @@
 #endif
 
 #define __deprecated   __attribute__((deprecated))
+#ifndef __packed
 #define __packed   __attribute__((packed))
+#endif
+#ifndef __weak
 #define __weak __attribute__((weak))
+#endif
 
 /*
  * it doesn't make sense on ARM (currently the only user of __naked) to trace
@@ -91,8 +95,12 @@
  * would be.
  * [...]
  */
+#ifndef __pure
 #define __pure __attribute__((pure))
+#endif
+#ifndef __aligned
 #define __aligned(x)   __attribute__((aligned(x)))
+#endif
 #define __printf(a, b) __attribute__((format(printf, a, b)))
 #define __scanf(a, b)  __attribute__((format(scanf, a, b)))
 #define  noinline  __attribute__((noinline))
@@ -115,4 +123,6 @@
  */
 #define uninitialized_var(x) x = x
 
+#ifndef __always_inline
 #define __always_inlineinline __attribute__((always_inline))
+#endif
-- 
2.1.0

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Re: [U-Boot] [PATCH v2 1/3] compiler_gcc: prevent redefining attributes

2014-09-18 Thread Masahiro Yamada

On Thu, 18 Sep 2014 20:10:27 +0200
Jeroen Hofstee jer...@myspectrum.nl wrote:

 The libc headers on FreeBSD and likely related projects as well contain an
 header file, cdefs.h which provides similiar functionality as 
 linux/compiler.h.
 It provides compiler independent defines like __weak __packed, to allow
 compiling with multiple compilers which might have a different syntax for such
 extension.
 
 Since that header file is included in multiple standard headers, like stddef.h
 and stdarg.h, multiple definitions of those defines will be present if both 
 are
 included. When compiling u-boot the compiler will warn about it hundreds of
 times since e.g. common.h will include both files indirectly.
 
 commit 7ea50d52849fe8ffa5b5b74c979b60b1045d6fc9 compiler_gcc: do not redefine
 __gnu_attributes prevented such redefinitions, but this was undone by commit
 fb8ffd7cfc68b3dc44e182356a207d784cb30b34 compiler*.h: sync
 include/linux/compiler*.h with Linux 3.16.
 
 Add the checks back where necessary to prevent such warnings.
 
 As the original patch this checkpatch warning is ignored:
 WARNING: Adding new packed members is to be done with care
 
 Cc: Masahiro Yamada yamad...@jp.panasonic.com
 Cc: Tom Rini tr...@ti.com
 Signed-off-by: Jeroen Hofstee jer...@myspectrum.nl


Acked-by: Masahiro Yamada yamad...@jp.panasonic.com

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