Newlib: implement locks

* Dynamically allocate arc4random data. Saves about 1k off the bss.

libc/xtensa-lx106-elf/include/machine/_arc4random.h

@@ -1 +1,32 @@
-/* Use default implementation, see arc4random.h */
+/*
+ * Copyright (c) 2017
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/cdefs.h>
+
+__BEGIN_DECLS
+
+void _arc4random_getentropy_fail(void);
+
+#define _ARC4RANDOM_DATA
+
+#define _ARC4RANDOM_GETENTROPY_FAIL() _arc4random_getentropy_fail()
+
+#define _ARC4RANDOM_ALLOCATE(rsp, rsxp)  \
+  do { *rsp = malloc(sizeof(**rsp));     \
+       *rsxp = malloc(sizeof(**rsxp)); } \
+  while (0)
+
+__END_DECLS

libc/xtensa-lx106-elf/include/machine/ieeefp.h

@@ -48,6 +48,23 @@
         This represents what type a float arg is passed as.  It is used when the type is
         not promoted to double.
 	
+
+   __OBSOLETE_MATH_DEFAULT
+
+	Default value for __OBSOLETE_MATH if that's not set by the user.
+	It should be set here based on predefined feature macros.
+
+   __OBSOLETE_MATH
+
+	If set to 1 then some new math code will be disabled and older libm
+	code will be used instead.  This is necessary because the new math
+	code does not support all targets, it assumes that the toolchain has
+	ISO C99 support (hexfloat literals, standard fenv semantics), the
+	target has IEEE-754 conforming binary32 float and binary64 double
+	(not mixed endian) representation, standard SNaN representation,
+	double and single precision arithmetics has similar latency and it
+	has no legacy SVID matherr support, only POSIX errno and fenv
+	exception based error handling.
 */
 
 #if (defined(__arm__) || defined(__thumb__)) && !defined(__MAVERICK__)
@@ -61,6 +78,7 @@
 # else
 #  define __IEEE_BIG_ENDIAN
 # endif
+# define __OBSOLETE_MATH_DEFAULT 0
 #else
 # define __IEEE_BIG_ENDIAN
 # ifdef __ARMEL__
@@ -75,6 +93,7 @@
 #else
 #define __IEEE_BIG_ENDIAN
 #endif
+#define __OBSOLETE_MATH_DEFAULT 0
 #endif
 
 #ifdef __epiphany__
@@ -435,6 +454,14 @@
 # endif
 #endif
 
+#ifndef __OBSOLETE_MATH_DEFAULT
+/* Use old math code by default.  */
+#define __OBSOLETE_MATH_DEFAULT 1
+#endif
+#ifndef __OBSOLETE_MATH
+#define __OBSOLETE_MATH __OBSOLETE_MATH_DEFAULT
+#endif
+
 #ifndef __IEEE_BIG_ENDIAN
 #ifndef __IEEE_LITTLE_ENDIAN
 #error Endianess not declared!!