POSIX states that #include <signal.h> shall make both mcontext_t and

ucontext_t available.  Our code even has XXX comment about this.

Add a bit of compliance by moving struct __ucontext definition into
sys/_ucontext.h and including it into signal.h and sys/ucontext.h.

Several machine/ucontext.h headers were changed to use namespace-safe
types (like uint64_t->__uint64_t) to not depend on sys/types.h.
struct __stack_t from sys/signal.h is made always visible in private
namespace to satisfy sys/_ucontext.h requirements.

Apparently mips _types.h pollutes global namespace with f_register_t
type definition.  This commit does not try to fix the issue.

PR:	207079
Reported and tested by:	Ting-Wei Lan <lantw44@gmail.com>
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks

include/signal.h

@@ -36,6 +36,8 @@
 #include <sys/cdefs.h>
 #include <sys/_types.h>
 #include <sys/signal.h>
+#include <machine/ucontext.h>
+#include <sys/_ucontext.h>
 
 #if __BSD_VISIBLE
 /*
@@ -114,7 +116,6 @@ void	psignal(unsigned int, const char *);
 
 #if __BSD_VISIBLE
 int	sigblock(int);
-struct __ucontext;		/* XXX spec requires a complete declaration. */
 int	sigreturn(const struct __ucontext *);
 int	sigsetmask(int);
 int	sigstack(const struct sigstack *, struct sigstack *);

sys/mips/include/ucontext.h

@@ -50,13 +50,13 @@ typedef struct	__mcontext {
 	 * struct sigcontext and ucontext_t at the same time.
 	 */
 	int		mc_onstack;	/* sigstack state to restore */
-	register_t	mc_pc;		/* pc at time of signal */
-	register_t	mc_regs[32];	/* processor regs 0 to 31 */
-	register_t	sr;		/* status register */
-	register_t	mullo, mulhi;	/* mullo and mulhi registers... */
+	__register_t	mc_pc;		/* pc at time of signal */
+	__register_t	mc_regs[32];	/* processor regs 0 to 31 */
+	__register_t	sr;		/* status register */
+	__register_t	mullo, mulhi;	/* mullo and mulhi registers... */
 	int		mc_fpused;	/* fp has been used */
 	f_register_t	mc_fpregs[33];	/* fp regs 0 to 31 and csr */
-	register_t	mc_fpc_eir;	/* fp exception instruction reg */
+	__register_t	mc_fpc_eir;	/* fp exception instruction reg */
 	void		*mc_tls;	/* pointer to TLS area */
 	int		__spare__[8];	/* XXX reserved */ 
 } mcontext_t;

sys/powerpc/include/ucontext.h

@@ -42,11 +42,11 @@ typedef struct __mcontext {
 #define _MC_AV_VALID	0x02
 	int		mc_onstack;	  	/* saved onstack flag */
 	int		mc_len;			/* sizeof(__mcontext) */
-	uint64_t	mc_avec[32*2];		/* vector register file */
-	uint32_t	mc_av[2];
-	register_t	mc_frame[42];
-	uint64_t	mc_fpreg[33];
-	uint64_t	mc_vsxfpreg[32];	/* low-order half of VSR0-31 */
+	__uint64_t	mc_avec[32*2];		/* vector register file */
+	__uint32_t	mc_av[2];
+	__register_t	mc_frame[42];
+	__uint64_t	mc_fpreg[33];
+	__uint64_t	mc_vsxfpreg[32];	/* low-order half of VSR0-31 */
 } mcontext_t __aligned(16);
 
 #if defined(_KERNEL) && defined(__powerpc64__)

sys/sparc64/include/ucontext.h

@@ -33,11 +33,11 @@
 #define	_MACHINE_UCONTEXT_H_
 
 struct __mcontext {
-	uint64_t mc_global[8];
-	uint64_t mc_out[8];
-	uint64_t mc_local[8];
-	uint64_t mc_in[8];
-	uint32_t mc_fp[64];
+	__uint64_t mc_global[8];
+	__uint64_t mc_out[8];
+	__uint64_t mc_local[8];
+	__uint64_t mc_in[8];
+	__uint32_t mc_fp[64];
 } __aligned(64);
 
 typedef struct __mcontext mcontext_t;

sys/sys/_ucontext.h

@@ -0,0 +1,52 @@
+/*-
+ * Copyright (c) 1999 Marcel Moolenaar
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer 
+ *    in this position and unchanged.
+ * 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. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef _SYS__UCONTEXT_H_
+#define	_SYS__UCONTEXT_H_
+
+typedef struct __ucontext {
+	/*
+	 * Keep the order of the first two fields. Also,
+	 * keep them the first two fields in the structure.
+	 * This way we can have a union with struct
+	 * sigcontext and ucontext_t. This allows us to
+	 * support them both at the same time.
+	 * note: the union is not defined, though.
+	 */
+	__sigset_t	uc_sigmask;
+	mcontext_t	uc_mcontext;
+
+	struct __ucontext *uc_link;
+	struct __stack_t uc_stack;
+	int		uc_flags;
+	int		__spare__[4];
+} ucontext_t;
+
+#endif /* _SYS__UCONTEXT_H */

sys/sys/signal.h

@@ -354,18 +354,10 @@ typedef	void __siginfohandler_t(int, struct __siginfo *, void *);
 #endif
 
 #if __XSI_VISIBLE
-/*
- * Structure used in sigaltstack call.
- */
 #if __BSD_VISIBLE
-typedef	struct sigaltstack {
-#else
-typedef	struct {
+#define	__stack_t sigaltstack
 #endif
-	void	*ss_sp;			/* signal stack base */
-	__size_t ss_size;		/* signal stack length */
-	int	ss_flags;		/* SS_DISABLE and/or SS_ONSTACK */
-} stack_t;
+typedef	struct __stack_t stack_t;
 
 #define	SS_ONSTACK	0x0001	/* take signal on alternate stack */
 #define	SS_DISABLE	0x0004	/* disable taking signals on alternate stack */
@@ -373,6 +365,17 @@ typedef	struct {
 #define	SIGSTKSZ	(MINSIGSTKSZ + 32768)	/* recommended stack size */
 #endif
 
+/*
+ * Structure used in sigaltstack call.  Its definition is always
+ * needed for __ucontext.  If __BSD_VISIBLE is defined, the structure
+ * tag is actually sigaltstack.
+ */
+struct __stack_t {
+	void	*ss_sp;			/* signal stack base */
+	__size_t ss_size;		/* signal stack length */
+	int	ss_flags;		/* SS_DISABLE and/or SS_ONSTACK */
+};
+
 #if __BSD_VISIBLE
 /*
  * 4.3 compatibility:

sys/sys/ucontext.h

@@ -33,25 +33,9 @@
 
 #include <sys/signal.h>
 #include <machine/ucontext.h>
+#include <sys/_ucontext.h>
 
-typedef struct __ucontext {
-	/*
-	 * Keep the order of the first two fields. Also,
-	 * keep them the first two fields in the structure.
-	 * This way we can have a union with struct
-	 * sigcontext and ucontext_t. This allows us to
-	 * support them both at the same time.
-	 * note: the union is not defined, though.
-	 */
-	sigset_t	uc_sigmask;
-	mcontext_t	uc_mcontext;
-
-	struct __ucontext *uc_link;
-	stack_t		uc_stack;
-	int		uc_flags;
 #define	UCF_SWAPPED	0x00000001	/* Used by swapcontext(3). */
-	int		__spare__[4];
-} ucontext_t;
 
 #if defined(_KERNEL) && defined(COMPAT_FREEBSD4)
 #if defined(__i386__)

sys/x86/include/ucontext.h

@@ -162,4 +162,9 @@ typedef struct __mcontext {
 } mcontext_t;
 #endif /* __amd64__ */
 
+#ifdef __LINT__
+typedef struct __mcontext {
+} mcontext_t;
+#endif /* __LINT__ */
+
 #endif /* !_X86_UCONTEXT_H_ */