[PATCH 07/14] FreeBSD update of __dead2, etc.

[Sebastian Huber]

newlib/ChangeLog
2013-04-17  Sebastian Huber <sebastian.huber@embedded-brains.de>

	* libc/include/sys/cdefs.h (__GNUC_PREREQ__): New define.
	(__aligned): Likewise.
	(__alignof): Likewise.
	(__dead2): Likewise.
	(__packed): Likewise.
	(__pure2): Likewise.
	(__section): Likewise.
	(__unused): Likewise.
	(__used): Likewise.
---
 newlib/libc/include/sys/cdefs.h |   59 ++++++++++++++++++++++++++++++++++++++-
 1 files changed, 58 insertions(+), 1 deletions(-)

diff --git a/newlib/libc/include/sys/cdefs.h b/newlib/libc/include/sys/cdefs.h
index 62c7aae..d8c32cc 100644
--- a/newlib/libc/include/sys/cdefs.h
+++ b/newlib/libc/include/sys/cdefs.h
@@ -147,6 +147,11 @@
 #endif /* __GNUC__ || __INTEL_COMPILER */
 
 /*
+ * Macro to test if we're using a specific version of gcc or later.
+ */
+#define	__GNUC_PREREQ__(ma, mi)	__GNUC_PREREQ(ma, mi)
+
+/*
  * The __CONCAT macro is used to concatenate parts of symbol names, e.g.
  * with "#define OLD(foo) __CONCAT(old,foo)", OLD(foo) produces oldfoo.
  * The __CONCAT macro is a bit tricky to use if it must work in non-ANSI
@@ -204,12 +209,64 @@
 #endif	/* !(__STDC__ || __cplusplus) */
 
 /*
+ * Compiler-dependent macros to help declare dead (non-returning) and
+ * pure (no side effects) functions, and unused variables.  They are
+ * null except for versions of gcc that are known to support the features
+ * properly (old versions of gcc-2 supported the dead and pure features
+ * in a different (wrong) way).  If we do not provide an implementation
+ * for a given compiler, let the compile fail if it is told to use
+ * a feature that we cannot live without.
+ */
+#ifdef lint
+#define	__dead2
+#define	__pure2
+#define	__unused
+#define	__packed
+#define	__aligned(x)
+#define	__section(x)
+#else
+#if !__GNUC_PREREQ__(2, 5) && !defined(__INTEL_COMPILER)
+#define	__dead2
+#define	__pure2
+#define	__unused
+#endif
+#if __GNUC__ == 2 && __GNUC_MINOR__ >= 5 && __GNUC_MINOR__ < 7 && !defined(__INTEL_COMPILER)
+#define	__dead2		__attribute__((__noreturn__))
+#define	__pure2		__attribute__((__const__))
+#define	__unused
+/* XXX Find out what to do for __packed, __aligned and __section */
+#endif
+#if __GNUC_PREREQ__(2, 7)
+#define	__dead2		__attribute__((__noreturn__))
+#define	__pure2		__attribute__((__const__))
+#define	__unused	__attribute__((__unused__))
+#define	__used		__attribute__((__used__))
+#define	__packed	__attribute__((__packed__))
+#define	__aligned(x)	__attribute__((__aligned__(x)))
+#define	__section(x)	__attribute__((__section__(x)))
+#endif
+#if defined(__INTEL_COMPILER)
+#define __dead2		__attribute__((__noreturn__))
+#define __pure2		__attribute__((__const__))
+#define __unused	__attribute__((__unused__))
+#define __used		__attribute__((__used__))
+#define __packed	__attribute__((__packed__))
+#define __aligned(x)	__attribute__((__aligned__(x)))
+#define __section(x)	__attribute__((__section__(x)))
+#endif
+#endif
+
+#if !__GNUC_PREREQ__(2, 95)
+#define	__alignof(x)	__offsetof(struct { char __a; x __b; }, __b)
+#endif
+
+/*
  * Given the pointer x to the member m of the struct s, return
  * a pointer to the containing structure.  When using GCC, we first
  * assign pointer x to a local variable, to check that its type is
  * compatible with member m.
  */
-#if __GNUC_PREREQ(3, 1)
+#if __GNUC_PREREQ__(3, 1)
 #define	__containerof(x, s, m) ({					\
 	const volatile __typeof__(((s *)0)->m) *__x = (x);		\
 	__DEQUALIFY(s *, (const volatile char *)__x - offsetof(s, m));\
-- 
1.7.7