* libc/include/sys/cdefs.h: Align with latest FreeBSD file header.

	* libc/include/sys/features.h (__GNUC_PREREQ__): Define.

2 files changed, 533 insertions, 48 deletions

diff --git a/newlib/libc/include/sys/cdefs.h b/newlib/libc/include/sys/cdefs.h
index 253258aa8..beeea3251 100644
--- a/newlib/libc/include/sys/cdefs.h
+++ b/newlib/libc/include/sys/cdefs.h
@@ -2,7 +2,7 @@
 
 /* Written 2000 by Werner Almesberger */
 
-/*
+/*-
  * Copyright (c) 1991, 1993
  *	The Regents of the University of California.  All rights reserved.
  *
@@ -17,10 +17,6 @@
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
- * 3. All advertising materials mentioning features or use of this software
- *    must display the following acknowledgement:
- *	This product includes software developed by the University of
- *	California, Berkeley and its contributors.
  * 4. Neither the name of the University nor the names of its contributors
  *    may be used to endorse or promote products derived from this software
  *    without specific prior written permission.
@@ -38,30 +34,112 @@
  * SUCH DAMAGE.
  *
  *	@(#)cdefs.h	8.8 (Berkeley) 1/9/95
- * $FreeBSD: src/sys/sys/cdefs.h,v 1.54 2002/05/11 03:58:24 alfred Exp $
+ * $FreeBSD$
  */
 
-#ifndef _SYS_CDEFS_H
-#define _SYS_CDEFS_H
+#ifndef	_SYS_CDEFS_H_
+#define	_SYS_CDEFS_H_
 
 #include <sys/features.h>
 #include <stddef.h>
 #include <stdint.h>
 
-#define __FBSDID(x) /* nothing */
-/*
- * Note: the goal here is not compatibility to K&R C. Since we know that we
- * have GCC which understands ANSI C perfectly well, we make use of this.
- */
-
-#define __P(args)	args
 #define __PMT(args)	args
-#define __const		const
-#define __signed	signed
-#define __volatile	volatile
 #define __DOTS    	, ...
 #define __THROW
 
+#ifdef __GNUC__
+# define __ASMNAME(cname)  __XSTRING (__USER_LABEL_PREFIX__) cname
+#endif
+
+#define __ptr_t void *
+#define __long_double_t  long double
+
+#define __attribute_malloc__
+#define __attribute_pure__
+#define __attribute_format_strfmon__(a,b)
+#define __flexarr      [0]
+
+#ifndef __BOUNDED_POINTERS__
+# define __bounded      /* nothing */
+# define __unbounded    /* nothing */
+# define __ptrvalue     /* nothing */
+#endif
+
+#if defined(__cplusplus)
+#define	__BEGIN_DECLS	extern "C" {
+#define	__END_DECLS	}
+#else
+#define	__BEGIN_DECLS
+#define	__END_DECLS
+#endif
+
+/*
+ * This code has been put in place to help reduce the addition of
+ * compiler specific defines in FreeBSD code.  It helps to aid in
+ * having a compiler-agnostic source tree.
+ */
+
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+
+#if __GNUC__ >= 3 || defined(__INTEL_COMPILER)
+#define __GNUCLIKE_ASM 3
+#define __GNUCLIKE_MATH_BUILTIN_CONSTANTS
+#else
+#define __GNUCLIKE_ASM 2
+#endif
+#define __GNUCLIKE___TYPEOF 1
+#define __GNUCLIKE___OFFSETOF 1
+#define __GNUCLIKE___SECTION 1
+
+#ifndef __INTEL_COMPILER
+# define __GNUCLIKE_CTOR_SECTION_HANDLING 1
+#endif
+
+#define __GNUCLIKE_BUILTIN_CONSTANT_P 1
+# if defined(__INTEL_COMPILER) && defined(__cplusplus) \
+    && __INTEL_COMPILER < 800
+#  undef __GNUCLIKE_BUILTIN_CONSTANT_P
+# endif
+
+#if (__GNUC_MINOR__ > 95 || __GNUC__ >= 3) && !defined(__INTEL_COMPILER)
+# define __GNUCLIKE_BUILTIN_VARARGS 1
+# define __GNUCLIKE_BUILTIN_STDARG 1
+# define __GNUCLIKE_BUILTIN_VAALIST 1
+#endif
+
+#if defined(__GNUC__)
+# define __GNUC_VA_LIST_COMPATIBILITY 1
+#endif
+
+/*
+ * Compiler memory barriers, specific to gcc and clang.
+ */
+#if defined(__GNUC__)
+#define	__compiler_membar()	__asm __volatile(" " : : : "memory")
+#endif
+
+#ifndef __INTEL_COMPILER
+# define __GNUCLIKE_BUILTIN_NEXT_ARG 1
+# define __GNUCLIKE_MATH_BUILTIN_RELOPS
+#endif
+
+#define __GNUCLIKE_BUILTIN_MEMCPY 1
+
+/* XXX: if __GNUC__ >= 2: not tested everywhere originally, where replaced */
+#define __CC_SUPPORTS_INLINE 1
+#define __CC_SUPPORTS___INLINE 1
+#define __CC_SUPPORTS___INLINE__ 1
+
+#define __CC_SUPPORTS___FUNC__ 1
+#define __CC_SUPPORTS_WARNING 1
+
+#define __CC_SUPPORTS_VARADIC_XXX 1 /* see varargs.h */
+
+#define __CC_SUPPORTS_DYNAMIC_ARRAY_INIT 1
+
+#endif /* __GNUC__ || __INTEL_COMPILER */
+
 /*
  * The __CONCAT macro is used to concatenate parts of symbol names, e.g.
  * with "#define OLD(foo) __CONCAT(old,foo)", OLD(foo) produces oldfoo.
@@ -74,60 +152,307 @@
  * __XSTRING is like __STRING, but it expands any macros in its argument
  * first.  It is only available with ANSI C.
  */
-#define __CONCAT1(x,y)  x ## y
-#define __CONCAT(x,y)   __CONCAT1(x,y)
-#define __STRING(x)     #x              /* stringify without expanding x */
-#define __XSTRING(x)    __STRING(x)     /* expand x, then stringify */
+#if defined(__STDC__) || defined(__cplusplus)
+#define	__P(protos)	protos		/* full-blown ANSI C */
+#define	__CONCAT1(x,y)	x ## y
+#define	__CONCAT(x,y)	__CONCAT1(x,y)
+#define	__STRING(x)	#x		/* stringify without expanding x */
+#define	__XSTRING(x)	__STRING(x)	/* expand x, then stringify */
 
-#ifdef __GNUC__
-# define __ASMNAME(cname)  __XSTRING (__USER_LABEL_PREFIX__) cname
+#define	__const		const		/* define reserved names to standard */
+#define	__signed	signed
+#define	__volatile	volatile
+#if defined(__cplusplus)
+#define	__inline	inline		/* convert to C++ keyword */
+#else
+#if !(defined(__CC_SUPPORTS___INLINE))
+#define	__inline			/* delete GCC keyword */
+#endif /* ! __CC_SUPPORTS___INLINE */
+#endif /* !__cplusplus */
+
+#else	/* !(__STDC__ || __cplusplus) */
+#define	__P(protos)	()		/* traditional C preprocessor */
+#define	__CONCAT(x,y)	x/**/y
+#define	__STRING(x)	"x"
+
+#if !defined(__CC_SUPPORTS___INLINE)
+#define	__const				/* delete pseudo-ANSI C keywords */
+#define	__inline
+#define	__signed
+#define	__volatile
+/*
+ * In non-ANSI C environments, new programs will want ANSI-only C keywords
+ * deleted from the program and old programs will want them left alone.
+ * When using a compiler other than gcc, programs using the ANSI C keywords
+ * const, inline etc. as normal identifiers should define -DNO_ANSI_KEYWORDS.
+ * When using "gcc -traditional", we assume that this is the intent; if
+ * __GNUC__ is defined but __STDC__ is not, we leave the new keywords alone.
+ */
+#ifndef	NO_ANSI_KEYWORDS
+#define	const				/* delete ANSI C keywords */
+#define	inline
+#define	signed
+#define	volatile
+#endif	/* !NO_ANSI_KEYWORDS */
+#endif	/* !__CC_SUPPORTS___INLINE */
+#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
 
-#define __ptr_t void *
-#define __long_double_t  long double
+#if !__GNUC_PREREQ__(2, 95)
+#define	__alignof(x)	__offsetof(struct { char __a; x __b; }, __b)
+#endif
 
-#define __attribute_malloc__
-#define __attribute_pure__
-#define __attribute_format_strfmon__(a,b)
-#define __flexarr      [0]
+/*
+ * Keywords added in C11.
+ */
+#if defined(__cplusplus) && __cplusplus >= 201103L
+#define	_Alignas(e)		alignas(e)
+#define	_Alignof(e)		alignof(e)
+#define	_Noreturn		[[noreturn]]
+#define	_Static_assert(e, s)	static_assert(e, s)
+/* FIXME: change this to thread_local when clang in base supports it */
+#define	_Thread_local		__thread
+#elif defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L
+/* Do nothing.  They are language keywords. */
+#else
+/* Not supported.  Implement them using our versions. */
+#define	_Alignas(x)		__aligned(x)
+#define	_Alignof(x)		__alignof(x)
+#define	_Noreturn		__dead2
+#define	_Thread_local		__thread
+#ifdef __COUNTER__
+#define	_Static_assert(x, y)	__Static_assert(x, __COUNTER__)
+#define	__Static_assert(x, y)	___Static_assert(x, y)
+#define	___Static_assert(x, y)	typedef char __assert_ ## y[(x) ? 1 : -1]
+#else
+#define	_Static_assert(x, y)	struct __hack
+#endif
+#endif
+
+/*
+ * Emulation of C11 _Generic().  Unlike the previously defined C11
+ * keywords, it is not possible to implement this using exactly the same
+ * syntax.  Therefore implement something similar under the name
+ * __generic().  Unlike _Generic(), this macro can only distinguish
+ * between a single type, so it requires nested invocations to
+ * distinguish multiple cases.
+ */
 
-#ifdef  __cplusplus
-# define __BEGIN_DECLS  extern "C" {
-# define __END_DECLS    }
+#if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L
+#define	__generic(expr, t, yes, no)					\
+	_Generic(expr, t: yes, default: no)
+#elif __GNUC_PREREQ__(3, 1) && !defined(__cplusplus)
+#define	__generic(expr, t, yes, no)					\
+	__builtin_choose_expr(						\
+	    __builtin_types_compatible_p(__typeof(expr), t), yes, no)
+#endif
+
+#if __GNUC_PREREQ__(2, 96)
+#define	__malloc_like	__attribute__((__malloc__))
+#define	__pure		__attribute__((__pure__))
 #else
-# define __BEGIN_DECLS
-# define __END_DECLS
+#define	__malloc_like
+#define	__pure
 #endif
 
-#ifndef __BOUNDED_POINTERS__
-# define __bounded      /* nothing */
-# define __unbounded    /* nothing */
-# define __ptrvalue     /* nothing */
+#if __GNUC_PREREQ__(3, 1) || (defined(__INTEL_COMPILER) && __INTEL_COMPILER >= 800)
+#define	__always_inline	__attribute__((__always_inline__))
+#else
+#define	__always_inline
+#endif
+
+#if __GNUC_PREREQ__(3, 1)
+#define	__noinline	__attribute__ ((__noinline__))
+#else
+#define	__noinline
+#endif
+
+#if __GNUC_PREREQ__(3, 3)
+#define __nonnull(x)	__attribute__((__nonnull__(x)))
+#else
+#define __nonnull(x)
+#endif
+
+#if __GNUC_PREREQ__(3, 4)
+#define	__fastcall	__attribute__((__fastcall__))
+#else
+#define	__fastcall
+#endif
+
+#if __GNUC_PREREQ__(4, 1)
+#define	__returns_twice	__attribute__((__returns_twice__))
+#else
+#define	__returns_twice
+#endif
+
+/* XXX: should use `#if __STDC_VERSION__ < 199901'. */
+#if !__GNUC_PREREQ__(2, 7) && !defined(__INTEL_COMPILER)
+#define	__func__	NULL
+#endif
+
+/*
+ * GCC 2.95 provides `__restrict' as an extension to C90 to support the
+ * C99-specific `restrict' type qualifier.  We happen to use `__restrict' as
+ * a way to define the `restrict' type qualifier without disturbing older
+ * software that is unaware of C99 keywords.
+ */
+#if !(__GNUC__ == 2 && __GNUC_MINOR__ == 95)
+#if !defined(__STDC_VERSION__) || __STDC_VERSION__ < 199901 || defined(lint)
+#define	__restrict
+#else
+#define	__restrict	restrict
+#endif
 #endif
 
 /*
+ * GNU C version 2.96 adds explicit branch prediction so that
+ * the CPU back-end can hint the processor and also so that
+ * code blocks can be reordered such that the predicted path
+ * sees a more linear flow, thus improving cache behavior, etc.
+ *
+ * The following two macros provide us with a way to utilize this
+ * compiler feature.  Use __predict_true() if you expect the expression
+ * to evaluate to true, and __predict_false() if you expect the
+ * expression to evaluate to false.
+ *
+ * A few notes about usage:
+ *
+ *	* Generally, __predict_false() error condition checks (unless
+ *	  you have some _strong_ reason to do otherwise, in which case
+ *	  document it), and/or __predict_true() `no-error' condition
+ *	  checks, assuming you want to optimize for the no-error case.
+ *
+ *	* Other than that, if you don't know the likelihood of a test
+ *	  succeeding from empirical or other `hard' evidence, don't
+ *	  make predictions.
+ *
+ *	* These are meant to be used in places that are run `a lot'.
+ *	  It is wasteful to make predictions in code that is run
+ *	  seldomly (e.g. at subsystem initialization time) as the
+ *	  basic block reordering that this affects can often generate
+ *	  larger code.
+ */
+#if __GNUC_PREREQ__(2, 96)
+#define __predict_true(exp)     __builtin_expect((exp), 1)
+#define __predict_false(exp)    __builtin_expect((exp), 0)
+#else
+#define __predict_true(exp)     (exp)
+#define __predict_false(exp)    (exp)
+#endif
+
+#if __GNUC_PREREQ__(4, 2)
+#define	__hidden	__attribute__((__visibility__("hidden")))
+#define	__exported	__attribute__((__visibility__("default")))
+#else
+#define	__hidden
+#define	__exported
+#endif
+
+#define __offsetof(type, field)	offsetof(type, field)
+#define	__rangeof(type, start, end) \
+	(__offsetof(type, end) - __offsetof(type, start))
+
+/*
  * 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));\
+	__DEQUALIFY(s *, (const volatile char *)__x - __offsetof(s, m));\
 })
 #else
 #define	__containerof(x, s, m)						\
-	__DEQUALIFY(s *, (const volatile char *)(x) - offsetof(s, m))
+	__DEQUALIFY(s *, (const volatile char *)(x) - __offsetof(s, m))
 #endif
 
-#ifndef	__DEQUALIFY
-#define	__DEQUALIFY(type, var)	((type)(uintptr_t)(const volatile void *)(var))
+/*
+ * Compiler-dependent macros to declare that functions take printf-like
+ * or scanf-like arguments.  They are null except for versions of gcc
+ * that are known to support the features properly (old versions of gcc-2
+ * didn't permit keeping the keywords out of the application namespace).
+ */
+#if !__GNUC_PREREQ__(2, 7) && !defined(__INTEL_COMPILER)
+#define	__printflike(fmtarg, firstvararg)
+#define	__scanflike(fmtarg, firstvararg)
+#define	__format_arg(fmtarg)
+#define	__strfmonlike(fmtarg, firstvararg)
+#define	__strftimelike(fmtarg, firstvararg)
+#else
+#define	__printflike(fmtarg, firstvararg) \
+	    __attribute__((__format__ (__printf__, fmtarg, firstvararg)))
+#define	__scanflike(fmtarg, firstvararg) \
+	    __attribute__((__format__ (__scanf__, fmtarg, firstvararg)))
+#define	__format_arg(fmtarg)	__attribute__((__format_arg__ (fmtarg)))
+#define	__strfmonlike(fmtarg, firstvararg) \
+	    __attribute__((__format__ (__strfmon__, fmtarg, firstvararg)))
+#define	__strftimelike(fmtarg, firstvararg) \
+	    __attribute__((__format__ (__strftime__, fmtarg, firstvararg)))
 #endif
 
-#ifdef __GNUC__
+/* Compiler-dependent macros that rely on FreeBSD-specific extensions. */
+#if defined(__FreeBSD_cc_version) && __FreeBSD_cc_version >= 300001 && \
+    defined(__GNUC__) && !defined(__INTEL_COMPILER)
+#define	__printf0like(fmtarg, firstvararg) \
+	    __attribute__((__format__ (__printf0__, fmtarg, firstvararg)))
+#else
+#define	__printf0like(fmtarg, firstvararg)
+#endif
+
+#if defined(__GNUC__) || defined(__INTEL_COMPILER)
+#ifndef __INTEL_COMPILER
 #define	__strong_reference(sym,aliassym)	\
-	extern __typeof (sym) aliassym __attribute__ ((__alias__ (#sym)));
+	extern __typeof (sym) aliassym __attribute__ ((__alias__ (#sym)))
+#endif
 #ifdef __ELF__
 #ifdef __STDC__
 #define	__weak_reference(sym,alias)	\
@@ -137,6 +462,10 @@
 	__asm__(".section .gnu.warning." #sym);	\
 	__asm__(".asciz \"" msg "\"");	\
 	__asm__(".previous")
+#define	__sym_compat(sym,impl,verid)	\
+	__asm__(".symver " #impl ", " #sym "@" #verid)
+#define	__sym_default(sym,impl,verid)	\
+	__asm__(".symver " #impl ", " #sym "@@" #verid)
 #else
 #define	__weak_reference(sym,alias)	\
 	__asm__(".weak alias");		\
@@ -145,6 +474,10 @@
 	__asm__(".section .gnu.warning.sym"); \
 	__asm__(".asciz \"msg\"");	\
 	__asm__(".previous")
+#define	__sym_compat(sym,impl,verid)	\
+	__asm__(".symver impl, sym@verid")
+#define	__sym_default(impl,sym,verid)	\
+	__asm__(".symver impl, sym@@verid")
 #endif	/* __STDC__ */
 #else	/* !__ELF__ */
 #ifdef __STDC__
@@ -163,6 +496,156 @@
 	__asm__(".stabs \"_/**/sym\",1,0,0,0")
 #endif	/* __STDC__ */
 #endif	/* __ELF__ */
-#endif	/* __GNUC__ */
+#endif	/* __GNUC__ || __INTEL_COMPILER */
+
+#ifndef	__FBSDID
+#define	__FBSDID(s)	struct __hack
+#endif
+
+#ifndef	__RCSID
+#define	__RCSID(s)	struct __hack
+#endif
+
+#ifndef	__RCSID_SOURCE
+#define	__RCSID_SOURCE(s)	struct __hack
+#endif
+
+#ifndef	__SCCSID
+#define	__SCCSID(s)	struct __hack
+#endif
+
+#ifndef	__COPYRIGHT
+#define	__COPYRIGHT(s)	struct __hack
+#endif
+
+#ifndef	__DECONST
+#define	__DECONST(type, var)	((type)(uintptr_t)(const void *)(var))
+#endif
+
+#ifndef	__DEVOLATILE
+#define	__DEVOLATILE(type, var)	((type)(uintptr_t)(volatile void *)(var))
+#endif
+
+#ifndef	__DEQUALIFY
+#define	__DEQUALIFY(type, var)	((type)(uintptr_t)(const volatile void *)(var))
+#endif
+
+/*-
+ * The following definitions are an extension of the behavior originally
+ * implemented in <sys/_posix.h>, but with a different level of granularity.
+ * POSIX.1 requires that the macros we test be defined before any standard
+ * header file is included.
+ *
+ * Here's a quick run-down of the versions:
+ *  defined(_POSIX_SOURCE)		1003.1-1988
+ *  _POSIX_C_SOURCE == 1		1003.1-1990
+ *  _POSIX_C_SOURCE == 2		1003.2-1992 C Language Binding Option
+ *  _POSIX_C_SOURCE == 199309		1003.1b-1993
+ *  _POSIX_C_SOURCE == 199506		1003.1c-1995, 1003.1i-1995,
+ *					and the omnibus ISO/IEC 9945-1: 1996
+ *  _POSIX_C_SOURCE == 200112		1003.1-2001
+ *  _POSIX_C_SOURCE == 200809		1003.1-2008
+ *
+ * In addition, the X/Open Portability Guide, which is now the Single UNIX
+ * Specification, defines a feature-test macro which indicates the version of
+ * that specification, and which subsumes _POSIX_C_SOURCE.
+ *
+ * Our macros begin with two underscores to avoid namespace screwage.
+ */
+
+/* Deal with IEEE Std. 1003.1-1990, in which _POSIX_C_SOURCE == 1. */
+#if defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE == 1
+#undef _POSIX_C_SOURCE		/* Probably illegal, but beyond caring now. */
+#define	_POSIX_C_SOURCE		199009
+#endif
+
+/* Deal with IEEE Std. 1003.2-1992, in which _POSIX_C_SOURCE == 2. */
+#if defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE == 2
+#undef _POSIX_C_SOURCE
+#define	_POSIX_C_SOURCE		199209
+#endif
+
+/* Deal with various X/Open Portability Guides and Single UNIX Spec. */
+#ifdef _XOPEN_SOURCE
+#if _XOPEN_SOURCE - 0 >= 700
+#define	__XSI_VISIBLE		700
+#undef _POSIX_C_SOURCE
+#define	_POSIX_C_SOURCE		200809
+#elif _XOPEN_SOURCE - 0 >= 600
+#define	__XSI_VISIBLE		600
+#undef _POSIX_C_SOURCE
+#define	_POSIX_C_SOURCE		200112
+#elif _XOPEN_SOURCE - 0 >= 500
+#define	__XSI_VISIBLE		500
+#undef _POSIX_C_SOURCE
+#define	_POSIX_C_SOURCE		199506
+#endif
+#endif
+
+/*
+ * Deal with all versions of POSIX.  The ordering relative to the tests above is
+ * important.
+ */
+#if defined(_POSIX_SOURCE) && !defined(_POSIX_C_SOURCE)
+#define	_POSIX_C_SOURCE		198808
+#endif
+#ifdef _POSIX_C_SOURCE
+#if _POSIX_C_SOURCE >= 200809
+#define	__POSIX_VISIBLE		200809
+#define	__ISO_C_VISIBLE		1999
+#elif _POSIX_C_SOURCE >= 200112
+#define	__POSIX_VISIBLE		200112
+#define	__ISO_C_VISIBLE		1999
+#elif _POSIX_C_SOURCE >= 199506
+#define	__POSIX_VISIBLE		199506
+#define	__ISO_C_VISIBLE		1990
+#elif _POSIX_C_SOURCE >= 199309
+#define	__POSIX_VISIBLE		199309
+#define	__ISO_C_VISIBLE		1990
+#elif _POSIX_C_SOURCE >= 199209
+#define	__POSIX_VISIBLE		199209
+#define	__ISO_C_VISIBLE		1990
+#elif _POSIX_C_SOURCE >= 199009
+#define	__POSIX_VISIBLE		199009
+#define	__ISO_C_VISIBLE		1990
+#else
+#define	__POSIX_VISIBLE		198808
+#define	__ISO_C_VISIBLE		0
+#endif /* _POSIX_C_SOURCE */
+#else
+/*-
+ * Deal with _ANSI_SOURCE:
+ * If it is defined, and no other compilation environment is explicitly
+ * requested, then define our internal feature-test macros to zero.  This
+ * makes no difference to the preprocessor (undefined symbols in preprocessing
+ * expressions are defined to have value zero), but makes it more convenient for
+ * a test program to print out the values.
+ *
+ * If a program mistakenly defines _ANSI_SOURCE and some other macro such as
+ * _POSIX_C_SOURCE, we will assume that it wants the broader compilation
+ * environment (and in fact we will never get here).
+ */
+#if defined(_ANSI_SOURCE)	/* Hide almost everything. */
+#define	__POSIX_VISIBLE		0
+#define	__XSI_VISIBLE		0
+#define	__BSD_VISIBLE		0
+#define	__ISO_C_VISIBLE		1990
+#elif defined(_C99_SOURCE)	/* Localism to specify strict C99 env. */
+#define	__POSIX_VISIBLE		0
+#define	__XSI_VISIBLE		0
+#define	__BSD_VISIBLE		0
+#define	__ISO_C_VISIBLE		1999
+#elif defined(_C11_SOURCE)	/* Localism to specify strict C11 env. */
+#define	__POSIX_VISIBLE		0
+#define	__XSI_VISIBLE		0
+#define	__BSD_VISIBLE		0
+#define	__ISO_C_VISIBLE		2011
+#else				/* Default environment: show everything. */
+#define	__POSIX_VISIBLE		200809
+#define	__XSI_VISIBLE		700
+#define	__BSD_VISIBLE		1
+#define	__ISO_C_VISIBLE		2011
+#endif
+#endif
 
-#endif /* _SYS_CDEFS_H */
+#endif /* !_SYS_CDEFS_H_ */
diff --git a/newlib/libc/include/sys/features.h b/newlib/libc/include/sys/features.h
index f150706db..b5e003b5f 100644
--- a/newlib/libc/include/sys/features.h
+++ b/newlib/libc/include/sys/features.h
@@ -34,6 +34,8 @@ extern "C" {
 #  define __GNUC_PREREQ(maj, min) 0
 # endif
 #endif /* __GNUC_PREREQ */
+/* Version with trailing underscores for BSD compatibility. */
+#define	__GNUC_PREREQ__(ma, mi)	__GNUC_PREREQ(ma, mi)
 
 /* RTEMS adheres to POSIX -- 1003.1b with some features from annexes.  */