Rename struct ucontext tag (bug 21457).

The ucontext_t type has a tag struct ucontext.  As with previous such
issues for siginfo_t and stack_t, this tag is not permitted by POSIX
(is not in a reserved namespace), and so namespace conformance means
breaking C++ name mangling for this type.

In this case, the type does need to have some tag rather than just a
typedef name, because it includes a pointer to itself.  This patch
uses struct ucontext_t as the new tag, so the type is mangled as
ucontext_t (the POSIX *_t reservation applies in all namespaces, not
just the namespace of ordinary identifiers).  Another reserved name
such as struct __ucontext could of course be used.

Because of other namespace issues, this patch does not by itself fix
bug 21457 or allow any XFAILs to be removed.

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

	[BZ #21457]
	* sysdeps/arm/sys/ucontext.h (struct ucontext): Rename to struct
	ucontext_t.
	* sysdeps/generic/sys/ucontext.h (struct ucontext): Likewise.
	* sysdeps/i386/sys/ucontext.h (struct ucontext): Likewise.
	* sysdeps/m68k/sys/ucontext.h (struct ucontext): Likewise.
	* sysdeps/mips/sys/ucontext.h (struct ucontext): Likewise.
	* sysdeps/unix/sysv/linux/aarch64/sys/ucontext.h (struct
	ucontext): Likewise.
	* sysdeps/unix/sysv/linux/alpha/sys/ucontext.h (struct ucontext):
	Likewise.
	* sysdeps/unix/sysv/linux/arm/sys/ucontext.h (struct ucontext):
	Likewise.
	* sysdeps/unix/sysv/linux/hppa/sys/ucontext.h (struct ucontext):
	Likewise.
	* sysdeps/unix/sysv/linux/ia64/sys/ucontext.h (struct ucontext):
	Likewise.
	* sysdeps/unix/sysv/linux/m68k/sys/ucontext.h (struct ucontext):
	Likewise.
	* sysdeps/unix/sysv/linux/mips/sys/ucontext.h (struct ucontext):
	Likewise.
	* sysdeps/unix/sysv/linux/nios2/sys/ucontext.h (struct ucontext):
	Likewise.
	* sysdeps/unix/sysv/linux/powerpc/sys/ucontext.h (struct
	ucontext): Likewise.
	* sysdeps/unix/sysv/linux/s390/sys/ucontext.h (struct ucontext):
	Likewise.
	* sysdeps/unix/sysv/linux/sh/sys/ucontext.h (struct ucontext):
	Likewise.
	* sysdeps/unix/sysv/linux/sparc/sys/ucontext.h (struct ucontext):
	Likewise.
	* sysdeps/unix/sysv/linux/tile/sys/ucontext.h (struct ucontext):
	Likewise.
	* sysdeps/unix/sysv/linux/x86/sys/ucontext.h (struct ucontext):
	Likewise.
	* sysdeps/powerpc/powerpc32/backtrace.c (struct
	rt_signal_frame_32): Likewise.
	* sysdeps/powerpc/powerpc64/backtrace.c (struct signal_frame_64):
	Likewise.
	* sysdeps/unix/sysv/linux/aarch64/kernel_rt_sigframe.h (struct
	kernel_rt_sigframe): Likewise.
	* sysdeps/unix/sysv/linux/aarch64/sigcontextinfo.h (SIGCONTEXT):
	Likewise.
	* sysdeps/unix/sysv/linux/arm/register-dump.h (register_dump):
	Likewise.
	* sysdeps/unix/sysv/linux/arm/sigcontextinfo.h (SIGCONTEXT):
	Likewise.
	* sysdeps/unix/sysv/linux/hppa/profil-counter.h
	(__profil_counter): Likewise.
	* sysdeps/unix/sysv/linux/microblaze/sigcontextinfo.h
	(SIGCONTEXT): Likewise.
	* sysdeps/unix/sysv/linux/mips/kernel_rt_sigframe.h (struct
	kernel_rt_sigframe): Likewise.
	* sysdeps/unix/sysv/linux/nios2/kernel_rt_sigframe.h (struct
	kernel_rt_sigframe): Likewise.
	* sysdeps/unix/sysv/linux/nios2/sigcontextinfo.h (SIGCONTEXT):
	Likewise.
	* sysdeps/unix/sysv/linux/sh/makecontext.S (__makecontext):
	Likewise.
	* sysdeps/unix/sysv/linux/sparc/sparc64/makecontext.c
	(__start_context): Likewise.
	* sysdeps/unix/sysv/linux/tile/sigcontextinfo.h (SIGCONTEXT):
	Likewise.
	* sysdeps/unix/sysv/linux/x86_64/register-dump.h (register_dump):
	Likewise.
	* sysdeps/unix/sysv/linux/x86_64/sigcontextinfo.h (SIGCONTEXT):
	Likewise.

37 files changed, 130 insertions, 59 deletions

diff --git a/ChangeLog b/ChangeLog
index c8ea62669d..5663110435 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,73 @@
 2017-06-26  Joseph Myers  <joseph@codesourcery.com>
 
+	[BZ #21457]
+	* sysdeps/arm/sys/ucontext.h (struct ucontext): Rename to struct
+	ucontext_t.
+	* sysdeps/generic/sys/ucontext.h (struct ucontext): Likewise.
+	* sysdeps/i386/sys/ucontext.h (struct ucontext): Likewise.
+	* sysdeps/m68k/sys/ucontext.h (struct ucontext): Likewise.
+	* sysdeps/mips/sys/ucontext.h (struct ucontext): Likewise.
+	* sysdeps/unix/sysv/linux/aarch64/sys/ucontext.h (struct
+	ucontext): Likewise.
+	* sysdeps/unix/sysv/linux/alpha/sys/ucontext.h (struct ucontext):
+	Likewise.
+	* sysdeps/unix/sysv/linux/arm/sys/ucontext.h (struct ucontext):
+	Likewise.
+	* sysdeps/unix/sysv/linux/hppa/sys/ucontext.h (struct ucontext):
+	Likewise.
+	* sysdeps/unix/sysv/linux/ia64/sys/ucontext.h (struct ucontext):
+	Likewise.
+	* sysdeps/unix/sysv/linux/m68k/sys/ucontext.h (struct ucontext):
+	Likewise.
+	* sysdeps/unix/sysv/linux/mips/sys/ucontext.h (struct ucontext):
+	Likewise.
+	* sysdeps/unix/sysv/linux/nios2/sys/ucontext.h (struct ucontext):
+	Likewise.
+	* sysdeps/unix/sysv/linux/powerpc/sys/ucontext.h (struct
+	ucontext): Likewise.
+	* sysdeps/unix/sysv/linux/s390/sys/ucontext.h (struct ucontext):
+	Likewise.
+	* sysdeps/unix/sysv/linux/sh/sys/ucontext.h (struct ucontext):
+	Likewise.
+	* sysdeps/unix/sysv/linux/sparc/sys/ucontext.h (struct ucontext):
+	Likewise.
+	* sysdeps/unix/sysv/linux/tile/sys/ucontext.h (struct ucontext):
+	Likewise.
+	* sysdeps/unix/sysv/linux/x86/sys/ucontext.h (struct ucontext):
+	Likewise.
+	* sysdeps/powerpc/powerpc32/backtrace.c (struct
+	rt_signal_frame_32): Likewise.
+	* sysdeps/powerpc/powerpc64/backtrace.c (struct signal_frame_64):
+	Likewise.
+	* sysdeps/unix/sysv/linux/aarch64/kernel_rt_sigframe.h (struct
+	kernel_rt_sigframe): Likewise.
+	* sysdeps/unix/sysv/linux/aarch64/sigcontextinfo.h (SIGCONTEXT):
+	Likewise.
+	* sysdeps/unix/sysv/linux/arm/register-dump.h (register_dump):
+	Likewise.
+	* sysdeps/unix/sysv/linux/arm/sigcontextinfo.h (SIGCONTEXT):
+	Likewise.
+	* sysdeps/unix/sysv/linux/hppa/profil-counter.h
+	(__profil_counter): Likewise.
+	* sysdeps/unix/sysv/linux/microblaze/sigcontextinfo.h
+	(SIGCONTEXT): Likewise.
+	* sysdeps/unix/sysv/linux/mips/kernel_rt_sigframe.h (struct
+	kernel_rt_sigframe): Likewise.
+	* sysdeps/unix/sysv/linux/nios2/kernel_rt_sigframe.h (struct
+	kernel_rt_sigframe): Likewise.
+	* sysdeps/unix/sysv/linux/nios2/sigcontextinfo.h (SIGCONTEXT):
+	Likewise.
+	* sysdeps/unix/sysv/linux/sh/makecontext.S (__makecontext):
+	Likewise.
+	* sysdeps/unix/sysv/linux/sparc/sparc64/makecontext.c
+	(__start_context): Likewise.
+	* sysdeps/unix/sysv/linux/tile/sigcontextinfo.h (SIGCONTEXT):
+	Likewise.
+	* sysdeps/unix/sysv/linux/x86_64/register-dump.h (register_dump):
+	Likewise.
+	* sysdeps/unix/sysv/linux/x86_64/sigcontextinfo.h (SIGCONTEXT):
+	Likewise.
+
 	* sysdeps/i386/Implies: Add ieee754/float128.
 	* sysdeps/x86_64/Implies: Likewise.
 	* sysdeps/x86/bits/floatn.h: New file.
diff --git a/NEWS b/NEWS
index 960c9f8dad..a662be27f0 100644
--- a/NEWS
+++ b/NEWS
@@ -94,6 +94,9 @@ Version 2.26
 * The stack_t type no longer has the name struct sigaltstack.  This changes
   the C++ name mangling for interfaces involving this type.
 
+* The ucontext_t type no longer has the name struct ucontext.  This changes
+  the C++ name mangling for interfaces involving this type.
+
 * The synchronization that pthread_spin_unlock performs has been changed
   to now be equivalent to a C11 atomic store with release memory order to
   the spin lock's memory location.  This ensures correct synchronization
diff --git a/sysdeps/arm/sys/ucontext.h b/sysdeps/arm/sys/ucontext.h
index 722300a7f1..464a353a51 100644
--- a/sysdeps/arm/sys/ucontext.h
+++ b/sysdeps/arm/sys/ucontext.h
@@ -98,10 +98,10 @@ typedef struct
 #undef __ctx
 
 /* Userlevel context.  */
-typedef struct ucontext
+typedef struct ucontext_t
   {
     unsigned long int uc_flags;
-    struct ucontext *uc_link;
+    struct ucontext_t *uc_link;
     sigset_t uc_sigmask;
     stack_t uc_stack;
     mcontext_t uc_mcontext;
diff --git a/sysdeps/generic/sys/ucontext.h b/sysdeps/generic/sys/ucontext.h
index a64460c9ae..e4679d3d94 100644
--- a/sysdeps/generic/sys/ucontext.h
+++ b/sysdeps/generic/sys/ucontext.h
@@ -32,10 +32,10 @@
 typedef struct sigcontext mcontext_t;
 
 /* Userlevel context.  */
-typedef struct ucontext
+typedef struct ucontext_t
   {
     unsigned long int uc_flags;
-    struct ucontext *uc_link;
+    struct ucontext_t *uc_link;
     stack_t uc_stack;
     mcontext_t uc_mcontext;
     sigset_t uc_sigmask;
diff --git a/sysdeps/i386/sys/ucontext.h b/sysdeps/i386/sys/ucontext.h
index fb5df11965..be8c7e5408 100644
--- a/sysdeps/i386/sys/ucontext.h
+++ b/sysdeps/i386/sys/ucontext.h
@@ -126,10 +126,10 @@ typedef struct
 #undef __ctxt
 
 /* Userlevel context.  */
-typedef struct ucontext
+typedef struct ucontext_t
   {
     unsigned long int uc_flags;
-    struct ucontext *uc_link;
+    struct ucontext_t *uc_link;
     sigset_t uc_sigmask;
     stack_t uc_stack;
     mcontext_t uc_mcontext;
diff --git a/sysdeps/m68k/sys/ucontext.h b/sysdeps/m68k/sys/ucontext.h
index a742aaff9a..00c4af417a 100644
--- a/sysdeps/m68k/sys/ucontext.h
+++ b/sysdeps/m68k/sys/ucontext.h
@@ -113,10 +113,10 @@ typedef struct
 #endif
 
 /* Userlevel context.  */
-typedef struct ucontext
+typedef struct ucontext_t
 {
   unsigned long int uc_flags;
-  struct ucontext *uc_link;
+  struct ucontext_t *uc_link;
   sigset_t uc_sigmask;
   stack_t uc_stack;
   mcontext_t uc_mcontext;
diff --git a/sysdeps/mips/sys/ucontext.h b/sysdeps/mips/sys/ucontext.h
index 4bc1bc199a..d69656b5dc 100644
--- a/sysdeps/mips/sys/ucontext.h
+++ b/sysdeps/mips/sys/ucontext.h
@@ -159,14 +159,14 @@ typedef struct
 #undef __ctx
 
 /* Userlevel context.  */
-typedef struct ucontext
+typedef struct ucontext_t
 {
 #if _MIPS_SIM == _ABIO32
   unsigned long int uc_flags;
 #else
   __uint64_t uc_flags;
 #endif
-  struct ucontext *uc_link;
+  struct ucontext_t *uc_link;
   sigset_t uc_sigmask;
   stack_t uc_stack;
   mcontext_t uc_mcontext;
diff --git a/sysdeps/powerpc/powerpc32/backtrace.c b/sysdeps/powerpc/powerpc32/backtrace.c
index 394062136c..187c3b3349 100644
--- a/sysdeps/powerpc/powerpc32/backtrace.c
+++ b/sysdeps/powerpc/powerpc32/backtrace.c
@@ -64,7 +64,7 @@ is_sigtramp_address (void *nip)
 struct rt_signal_frame_32 {
   char               dummy[SIGNAL_FRAMESIZE + 16];
   siginfo_t          info;
-  struct ucontext    uc;
+  ucontext_t         uc;
   /* We don't care about the rest, since IP value is at 'uc' field.  */
 };
 
diff --git a/sysdeps/powerpc/powerpc64/backtrace.c b/sysdeps/powerpc/powerpc64/backtrace.c
index 723948d78f..919bf1cfd7 100644
--- a/sysdeps/powerpc/powerpc64/backtrace.c
+++ b/sysdeps/powerpc/powerpc64/backtrace.c
@@ -50,7 +50,7 @@ struct layout
 struct signal_frame_64 {
 #define SIGNAL_FRAMESIZE 128
   char dummy[SIGNAL_FRAMESIZE];
-  struct ucontext uc;
+  ucontext_t uc;
   /* We don't care about the rest, since the IP value is at 'uc' field.  */
 };
 
diff --git a/sysdeps/unix/sysv/linux/aarch64/kernel_rt_sigframe.h b/sysdeps/unix/sysv/linux/aarch64/kernel_rt_sigframe.h
index e67ddfa91c..cb65bd4159 100644
--- a/sysdeps/unix/sysv/linux/aarch64/kernel_rt_sigframe.h
+++ b/sysdeps/unix/sysv/linux/aarch64/kernel_rt_sigframe.h
@@ -21,5 +21,5 @@
 struct kernel_rt_sigframe
 {
   siginfo_t info;
-  struct ucontext uc;
+  ucontext_t uc;
 };
diff --git a/sysdeps/unix/sysv/linux/aarch64/sigcontextinfo.h b/sysdeps/unix/sysv/linux/aarch64/sigcontextinfo.h
index b28ad5bdcd..7793d110bb 100644
--- a/sysdeps/unix/sysv/linux/aarch64/sigcontextinfo.h
+++ b/sysdeps/unix/sysv/linux/aarch64/sigcontextinfo.h
@@ -19,7 +19,7 @@
 #include <stdint.h>
 #include <sys/ucontext.h>
 
-#define SIGCONTEXT siginfo_t *_si, struct ucontext *
+#define SIGCONTEXT siginfo_t *_si, ucontext_t *
 #define GET_PC(ctx) ((void *) (uintptr_t) (ctx)->uc_mcontext.pc)
 
 /* There is no reliable way to get the sigcontext unless we use a
diff --git a/sysdeps/unix/sysv/linux/aarch64/sys/ucontext.h b/sysdeps/unix/sysv/linux/aarch64/sys/ucontext.h
index 16c7acf221..4f602fc166 100644
--- a/sysdeps/unix/sysv/linux/aarch64/sys/ucontext.h
+++ b/sysdeps/unix/sysv/linux/aarch64/sys/ucontext.h
@@ -47,10 +47,10 @@ typedef elf_fpregset_t	fpregset_t;
 typedef struct sigcontext mcontext_t;
 
 /* Userlevel context.  */
-typedef struct ucontext
+typedef struct ucontext_t
   {
     unsigned long uc_flags;
-    struct ucontext *uc_link;
+    struct ucontext_t *uc_link;
     stack_t uc_stack;
     sigset_t uc_sigmask;
     mcontext_t uc_mcontext;
diff --git a/sysdeps/unix/sysv/linux/alpha/sys/ucontext.h b/sysdeps/unix/sysv/linux/alpha/sys/ucontext.h
index b9e590347e..bf95205140 100644
--- a/sysdeps/unix/sysv/linux/alpha/sys/ucontext.h
+++ b/sysdeps/unix/sysv/linux/alpha/sys/ucontext.h
@@ -54,10 +54,10 @@ typedef fpreg_t fpregset_t[__NFPREG];
 typedef struct sigcontext mcontext_t;
 
 /* Userlevel context.  */
-typedef struct ucontext
+typedef struct ucontext_t
   {
     unsigned long int uc_flags;
-    struct ucontext *uc_link;
+    struct ucontext_t *uc_link;
     unsigned long __uc_osf_sigmask;
     stack_t uc_stack;
     mcontext_t uc_mcontext;
diff --git a/sysdeps/unix/sysv/linux/arm/register-dump.h b/sysdeps/unix/sysv/linux/arm/register-dump.h
index 0f2bed7d1d..d31b3245ec 100644
--- a/sysdeps/unix/sysv/linux/arm/register-dump.h
+++ b/sysdeps/unix/sysv/linux/arm/register-dump.h
@@ -44,7 +44,7 @@ hexvalue (unsigned long int value, char *buf, size_t len)
 }
 
 static void
-register_dump (int fd, const struct ucontext *ctx)
+register_dump (int fd, const ucontext_t *ctx)
 {
   char regs[21][8];
   struct iovec iov[97];
diff --git a/sysdeps/unix/sysv/linux/arm/sigcontextinfo.h b/sysdeps/unix/sysv/linux/arm/sigcontextinfo.h
index f2a66d154d..d3313af24a 100644
--- a/sysdeps/unix/sysv/linux/arm/sigcontextinfo.h
+++ b/sysdeps/unix/sysv/linux/arm/sigcontextinfo.h
@@ -18,7 +18,7 @@
 
 #include <sys/ucontext.h>
 
-#define SIGCONTEXT siginfo_t *_si, struct ucontext *
+#define SIGCONTEXT siginfo_t *_si, ucontext_t *
 #define SIGCONTEXT_EXTRA_ARGS _si,
 
 /* The sigcontext structure changed between 2.0 and 2.1 kernels.  On any
diff --git a/sysdeps/unix/sysv/linux/arm/sys/ucontext.h b/sysdeps/unix/sysv/linux/arm/sys/ucontext.h
index 0ce9b14ba5..1083d66943 100644
--- a/sysdeps/unix/sysv/linux/arm/sys/ucontext.h
+++ b/sysdeps/unix/sysv/linux/arm/sys/ucontext.h
@@ -101,10 +101,10 @@ typedef struct _libc_fpstate fpregset_t;
 typedef struct sigcontext mcontext_t;
 
 /* Userlevel context.  */
-typedef struct ucontext
+typedef struct ucontext_t
   {
     unsigned long uc_flags;
-    struct ucontext *uc_link;