libc: Provide ucontext_t/mcontext_t/<sys/ucontext.h>

This patch updates the C library headers to provide ucontext_t
definitions for three architectures.

+ Fix <signal.h> to always define 'struct sigcontext'.

The new declarations are announced with new macros defined in
<sys/cdefs.h> in order to make it easier to adapt client code
that already defines its own, incompatible, versions of the
structures seen here.

http://code.google.com/p/android/issues/detail?id=34784

Change-Id: Ie78c48690a4ce61c50593f6c39639be7fead3596

libc/arch-mips/include/machine/setjmp.h

@@ -1,10 +1,56 @@
-/*	$OpenBSD: setjmp.h,v 1.2 2004/08/10 21:10:56 pefo Exp $	*/
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
 
-/* Public domain */
+#ifndef _ARCH_MIPS_MACHINE_SETJMP_H_
+#define _ARCH_MIPS_MACHINE_SETJMP_H_
 
-#ifndef _MIPS_SETJMP_H_
-#define _MIPS_SETJMP_H_
+#define _JBLEN          157    /* size, in longs, of a jmp_buf */
 
-#define	_JBLEN	157		/* size, in longs, of a jmp_buf */
+#define SC_REGMASK      (0*REGSZ)
+#define SC_STATUS       (1*REGSZ)
+#define SC_PC           (2*REGSZ)
+#define SC_REGS         (SC_PC+8)
+#define SC_FPREGS       (SC_REGS+32*8)
+#define SC_ACX          (SC_FPREGS+32*REGSZ_FP)
+#define SC_FPC_CSR      (SC_ACX+1*REGSZ)
+#define SC_FPC_EIR      (SC_ACX+2*REGSZ)
+#define SC_USED_MATH    (SC_ACX+3*REGSZ)
+#define SC_DSP          (SC_ACX+4*REGSZ)
+#define SC_MDHI         (SC_ACX+5*REGSZ)
+#define SC_MDLO         (SC_MDHI+8)
+#define SC_HI1          (SC_MDLO+8)
+#define SC_LO1          (SC_HI1+1*REGSZ)
+#define SC_HI2          (SC_HI1+2*REGSZ)
+#define SC_LO2          (SC_HI1+3*REGSZ)
+#define SC_HI3          (SC_HI1+4*REGSZ)
+#define SC_LO3          (SC_HI1+5*REGSZ)
+/* OpenBSD compatibility */
+#define SC_MASK         SC_REGMASK
+#define SC_FPUSED       SC_USED_MATH
 
-#endif /* !_MIPS_SETJMP_H_ */
+#endif /* !_ARCH_MIPS_INCLUDE_MACHINE_SETJMP_H_ */