Fix more namespace issues in sys/ucontext.h (bug 21457).

Continuing the fixes for namespace issues in sys/ucontext.h, this
patch moves various symbols into the implementation namespace in the
absence of __USE_MISC.  As with previous changes, it is nonexhaustive,
just covering more straightforward cases.

Structure fields are generally changed to have a prefix __ in the
absence of __USE_MISC, via a macro __ctx (used without a space before
the open parenthesis, since the result is a single identifier).
Various macros such as NGREG also have leading __ added.  No changes
are made to structure tags (and thus to C++ name mangling), except
that in the (unused) file sysdeps/i386/sys/ucontext.h, structures
defined inside other structures as the type for a field have their
tags removed in the non-__USE_MISC case (those structure tags would
not in any case have been visible in C++, because in C++ the scope of
such a tag is limited to the containing structure).  No changes are
made to the contents of bits/sigcontext.h, or to whether it is
included.  Because of remaining namespace issues, this patch does not
yet fix the bug or allow any XFAILs to be removed.

Tested for x86_64 and x86, and with build-many-glibcs.py.

	[BZ #21457]
	* sysdeps/arm/sys/ucontext.h (NGREG): Rename to __NGREG and define
	NGREG to __NGREG if [__USE_MISC].
	(gregset_t): Define using __NGREG.
	(__ctx): New macro.
	(mcontext_t): Use __ctx in defining fields.
	* sysdeps/i386/sys/ucontext.h (NGREG): Rename to __NGREG and
	define NGREG to __NGREG if [__USE_MISC].
	(gregset_t): Define using __NGREG.
	(__ctx): New macro.
	(__ctxt): Likewise.
	(fpregset_t): Use __ctx and __ctxt in defining fields.
	(mcontext_t): Likewise.
	* sysdeps/m68k/sys/ucontext.h (NGREG): Rename to __NGREG and
	define NGREG to __NGREG if [__USE_MISC].
	(gregset_t): Define using __NGREG.
	(__ctx): New macro.
	(mcontext_t): Use __ctx in defining fields.
	* sysdeps/mips/sys/ucontext.h (NGREG): Rename to __NGREG and
	define NGREG to __NGREG if [__USE_MISC].
	(gregset_t): Define using __NGREG.
	(__ctx): New macro.
	(fpregset_t): Use __ctx in defining fields.
	(mcontext_t): Likewise.
	* sysdeps/unix/sysv/linux/alpha/sys/ucontext.h (NGREG): Rename to
	__NGREG and define NGREG to __NGREG if [__USE_MISC].
	(gregset_t): Define using __NGREG.
	(NFPREG): Rename to __NFPREG and define NFPREG to __NFPREG if
	[__USE_MISC].
	(fpregset_t): Define using __NFPREG.
	* sysdeps/unix/sysv/linux/m68k/sys/ucontext.h (NGREG): Rename to
	__NGREG and define NGREG to __NGREG if [__USE_MISC].
	(gregset_t): Define using __NGREG.
	(__ctx): New macro.
	(fpregset_t): Use __ctx in defining fields.
	(mcontext_t): Likewise.
	* sysdeps/unix/sysv/linux/mips/sys/ucontext.h (NGREG): Rename to
	__NGREG and define NGREG to __NGREG if [__USE_MISC].
	(NFPREG): Rename to __NFPREG and define NFPREG to __NFPREG if
	[__USE_MISC].
	(gregset_t): Define using __NGREG.
	(__ctx): New macro.
	(fpregset_t): Use __ctx in defining fields.
	(mcontext_t): Likewise.
	* sysdeps/unix/sysv/linux/nios2/sys/ucontext.h (__ctx): New macro.
	(mcontext_t): Use __ctx in defining fields.
	* sysdeps/unix/sysv/linux/powerpc/sys/ucontext.h (__ctx): New
	macro.
	[__WORDSIZE == 32] (NGREG): Rename to __NGREG and define NGREG to
	__NGREG if [__USE_MISC].
	[__WORDSIZE == 32] (gregset_t): Define using __NGREG.
	[__WORDSIZE == 32] (fpregset_t): Use __ctx in defining fields.
	(mcontext_t): Likewise.
	[__WORDSIZE != 32] (NGREG): Rename to __NGREG and define NGREG to
	__NGREG if [__USE_MISC].
	[__WORDSIZE != 32] (NFPREG): Rename to __NFPREG and define NFPREG
	to __NFPREG if [__USE_MISC].
	[__WORDSIZE != 32] (NVRREG): Rename to __NVRREG and define NVRREG
	to __NVRREG if [__USE_MISC].
	[__WORDSIZE != 32] (gregset_t): Define using __NGREG.
	[__WORDSIZE != 32] (fpregset_t): Define using __NFPREG.
	[__WORDSIZE != 32] (vscr_t): Use __ctx in defining fields.
	[__WORDSIZE != 32] (vrregset_t): Likewise.
	[__WORDSIZE != 32] (mcontext_t): Likewise.
	* sysdeps/unix/sysv/linux/s390/sys/ucontext.h (__ctx): New macro.
	(__psw_t): Use __ctx in defining fields.
	(NGREG): Rename to __NGREG and define NGREG to __NGREG if
	[__USE_MISC].
	(gregset_t): Define using __NGREG.
	(fpreg_t): Use __ctx in defining fields.
	(fpregset_t): Likewise.
	(mcontext_t): Likewise.
	* sysdeps/unix/sysv/linux/sh/sys/ucontext.h (NGREG): Rename to
	__NGREG and define NGREG to __NGREG if [__USE_MISC].
	(gregset_t): Define using __NGREG.
	(NFPREG): Rename to __NFPREG and define NFPREG to __NFPREG if
	[__USE_MISC].
	(fpregset_t): Define using __NFPREG.
	(__ctx): New macro.
	(mcontext_t): Use __ctx in defining fields.
	* sysdeps/unix/sysv/linux/x86/sys/ucontext.h (__ctx): New macro.
	[__x86_64__] (NGREG): Rename to __NGREG and define NGREG to
	__NGREG if [__USE_MISC].
	[__x86_64__] (gregset_t): Define using __NGREG.
	[__x86_64__] (struct _libc_fpxreg): Use __ctx in defining fields.
	[__x86_64__] (struct _libc_fpstate): Likewise.
	[__x86_64__] (mcontext_t): Likewise.
	[!__x86_64__] (NGREG): Rename to __NGREG and define NGREG to
	__NGREG if [__USE_MISC].
	[!__x86_64__] (gregset_t): Define using __NGREG.
	[!__x86_64__] (struct _libc_fpreg): Use __ctx in defining fields.
	[!__x86_64__] (struct _libc_fpstate): Likewise.
	[!__x86_64__] (mcontext_t): Likewise.

1 files changed, 45 insertions, 28 deletions

diff --git a/sysdeps/unix/sysv/linux/powerpc/sys/ucontext.h b/sysdeps/unix/sysv/linux/powerpc/sys/ucontext.h
index c10741cf53..b460f23bc9 100644
--- a/sysdeps/unix/sysv/linux/powerpc/sys/ucontext.h
+++ b/sysdeps/unix/sysv/linux/powerpc/sys/ucontext.h
@@ -25,19 +25,28 @@
 #include <bits/types/stack_t.h>
 
 
+#ifdef __USE_MISC
+# define __ctx(fld) fld
+#else
+# define __ctx(fld) __ ## fld
+#endif
+
 #if __WORDSIZE == 32
 
 /* Number of general registers.  */
-# define NGREG	48
+# define __NGREG	48
+# ifdef __USE_MISC
+#  define NGREG	__NGREG
+# endif
 
 /* Container for all general registers.  */
-typedef unsigned long gregset_t[NGREG];
+typedef unsigned long gregset_t[__NGREG];
 
 /* Container for floating-point registers and status */
 typedef struct _libc_fpstate
 {
-	double fpregs[32];
-	double fpscr;
+	double __ctx(fpregs)[32];
+	double __ctx(fpscr);
 	unsigned int _pad[2];
 } fpregset_t;
 
@@ -45,18 +54,18 @@ typedef struct _libc_fpstate
    Needs to be aligned on a 16-byte boundary. */
 typedef struct _libc_vrstate
 {
-	unsigned int vrregs[32][4];
-	unsigned int vrsave;
+	unsigned int __ctx(vrregs)[32][4];
+	unsigned int __ctx(vrsave);
 	unsigned int _pad[2];
-	unsigned int vscr;
+	unsigned int __ctx(vscr);
 } vrregset_t;
 
 /* Context to describe whole processor state.  */
 typedef struct
 {
-	gregset_t gregs;
-	fpregset_t fpregs;
-	vrregset_t vrregs __attribute__((__aligned__(16)));
+	gregset_t __ctx(gregs);
+	fpregset_t __ctx(fpregs);
+	vrregset_t __ctx(vrregs) __attribute__((__aligned__(16)));
 } mcontext_t;
 
 #else
@@ -70,12 +79,18 @@ typedef struct
  * is set in AT_HWCAP.  */
 
 /* Number of general registers.  */
-# define NGREG	48	/* includes r0-r31, nip, msr, lr, etc.   */
-# define NFPREG	33	/* includes fp0-fp31 &fpscr.  */
-# define NVRREG	34	/* includes v0-v31, vscr, & vrsave in split vectors */
-
-typedef unsigned long gregset_t[NGREG];
-typedef double fpregset_t[NFPREG];
+# define __NGREG	48	/* includes r0-r31, nip, msr, lr, etc.   */
+# define __NFPREG	33	/* includes fp0-fp31 &fpscr.  */
+# define __NVRREG	34	/* includes v0-v31, vscr, & vrsave in
+				   split vectors */
+# ifdef __USE_MISC
+#  define NGREG	__NGREG
+#  define NFPREG	__NFPREG
+#  define NVRREG	__NVRREG
+# endif
+
+typedef unsigned long gregset_t[__NGREG];
+typedef double fpregset_t[__NFPREG];
 
 /* Container for Altivec/VMX Vector Status and Control Register.  Only 32-bits
    but can only be copied to/from a 128-bit vector register.  So we allocated
@@ -83,28 +98,28 @@ typedef double fpregset_t[NFPREG];
 typedef struct _libc_vscr
 {
 	unsigned int __pad[3];
-	unsigned int vscr_word;
+	unsigned int __ctx(vscr_word);
 } vscr_t;
 
 /* Container for Altivec/VMX registers and status.
    Must to be aligned on a 16-byte boundary. */
 typedef struct _libc_vrstate
 {
-	unsigned int	vrregs[32][4];
-	vscr_t		vscr;
-	unsigned int	vrsave;
+	unsigned int	__ctx(vrregs)[32][4];
+	vscr_t		__ctx(vscr);
+	unsigned int	__ctx(vrsave);
 	unsigned int	__pad[3];
 } vrregset_t  __attribute__((__aligned__(16)));
 
 typedef struct {
 	unsigned long	__glibc_reserved[4];
-	int		signal;
+	int		__ctx(signal);
 	int		__pad0;
-	unsigned long	handler;
-	unsigned long	oldmask;
-	struct pt_regs	*regs;
-	gregset_t	gp_regs;
-	fpregset_t	fp_regs;
+	unsigned long	__ctx(handler);
+	unsigned long	__ctx(oldmask);
+	struct pt_regs	*__ctx(regs);
+	gregset_t	__ctx(gp_regs);
+	fpregset_t	__ctx(fp_regs);
 /*
  * To maintain compatibility with current implementations the sigcontext is
  * extended by appending a pointer (v_regs) to a quadword type (elf_vrreg_t)
@@ -124,12 +139,14 @@ typedef struct {
  * The entry with index 33 contains the vrsave as the first word (offset 0)
  * within the quadword.
  */
-	vrregset_t	*v_regs;
-	long		vmx_reserve[NVRREG+NVRREG+1];
+	vrregset_t	*__ctx(v_regs);
+	long		__ctx(vmx_reserve)[__NVRREG+__NVRREG+1];
 } mcontext_t;
 
 #endif
 
+#undef __ctx
+
 /* Userlevel context.  */
 typedef struct ucontext
   {