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[libc] Rewrite unrelicensable portions of stddef.h

Signed-off-by: Michael Brown <mcb30@ipxe.org>
tags/v1.20.1
Michael Brown 9 years ago
parent
commit
5d1f351278
1 changed files with 29 additions and 11 deletions
  1. 29
    11
      src/include/stddef.h

+ 29
- 11
src/include/stddef.h View File

@@ -1,25 +1,43 @@
1 1
 #ifndef STDDEF_H
2 2
 #define STDDEF_H
3 3
 
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-FILE_LICENCE ( GPL2_ONLY );
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+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
5 5
 
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-/* for size_t */
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 #include <stdint.h>
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+/** EFI headers also define NULL */
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 #undef NULL
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-#define NULL ((void *)0)
11 10
 
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-#undef offsetof
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-#if ( defined ( __GNUC__ ) && ( __GNUC__ > 3 ) )
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-#define offsetof(TYPE, MEMBER) __builtin_offsetof(TYPE, MEMBER)
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+/** Null pointer */
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+#define NULL ( ( void * ) 0 )
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+
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+/**
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+ * Get offset of a field within a structure
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+ *
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+ * @v type		Structure type
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+ * @v field		Field within structure
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+ * @ret offset		Offset within structure
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+ */
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+#if defined ( __GNUC__ ) && ( __GNUC__ > 3 )
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+#define offsetof( type, field ) __builtin_offsetof ( type, field )
15 23
 #else
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-#define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
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+#define offsetof( type, field ) ( ( size_t ) &( ( ( type * ) NULL )->field ) )
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 #endif
18 26
 
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-#undef container_of
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-#define container_of(ptr, type, member) ({                      \
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-	const typeof( ((type *)0)->member ) *__mptr = (ptr);    \
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-	(type *)( (char *)__mptr - offsetof(type,member) );})
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+/**
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+ * Get containing structure
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+ *
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+ * @v ptr		Pointer to contained field
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+ * @v type		Containing structure type
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+ * @v field		Field within containing structure
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+ * @ret container	Pointer to containing structure
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+ */
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+#define container_of( ptr, type, field ) ( {				\
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+	type *__container;						\
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+	const typeof ( __container->field ) *__field = (ptr);		\
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+	__container = ( ( ( void * ) __field ) -			\
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+			offsetof ( type, field ) );			\
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+	__container; } )
23 41
 
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 /* __WCHAR_TYPE__ is defined by gcc and will change if -fshort-wchar is used */
25 43
 #ifndef __WCHAR_TYPE__

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