Use ucontext_t not struct ucontext in linux-unwind.h files

[Joseph Myers]

Current glibc no longer gives the ucontext_t type the tag struct
ucontext, to conform with POSIX namespace rules.  This requires
various linux-unwind.h files in libgcc, that were previously using
struct ucontext, to be fixed to use ucontext_t instead.  This is
similar to the removal of the struct siginfo tag from siginfo_t some
years ago.

This patch changes those files to use ucontext_t instead.  As the
standard name that should be unconditionally safe, so this is not
restricted to architectures supported by glibc, or conditioned on the
glibc version.

Testing compilation together with current glibc with glibc's
build-many-glibcs.py.  OK to commit (mainline and active release
branches) if that passes?

2017-06-27  Joseph Myers  <joseph@codesourcery.com>

	* config/aarch64/linux-unwind.h (aarch64_fallback_frame_state),
	config/alpha/linux-unwind.h (alpha_fallback_frame_state),
	config/bfin/linux-unwind.h (bfin_fallback_frame_state),
	config/i386/linux-unwind.h (x86_64_fallback_frame_state,
	x86_fallback_frame_state), config/m68k/linux-unwind.h (struct
	uw_ucontext), config/nios2/linux-unwind.h (struct nios2_ucontext),
	config/pa/linux-unwind.h (pa32_fallback_frame_state),
	config/riscv/linux-unwind.h (riscv_fallback_frame_state),
	config/sh/linux-unwind.h (sh_fallback_frame_state),
	config/tilepro/linux-unwind.h (tile_fallback_frame_state),
	config/xtensa/linux-unwind.h (xtensa_fallback_frame_state): Use
	ucontext_t instead of struct ucontext.

Index: libgcc/config/aarch64/linux-unwind.h
===================================================================
--- libgcc/config/aarch64/linux-unwind.h	(revision 249686)
+++ libgcc/config/aarch64/linux-unwind.h	(working copy)
@@ -55,7 +55,7 @@ aarch64_fallback_frame_state (struct _Unwind_Conte
   struct rt_sigframe
   {
     siginfo_t info;
-    struct ucontext uc;
+    ucontext_t uc;
   };
 
   struct rt_sigframe *rt_;
Index: libgcc/config/alpha/linux-unwind.h
===================================================================
--- libgcc/config/alpha/linux-unwind.h	(revision 249686)
+++ libgcc/config/alpha/linux-unwind.h	(working copy)
@@ -51,7 +51,7 @@ alpha_fallback_frame_state (struct _Unwind_Context
     {
       struct rt_sigframe {
 	siginfo_t info;
-	struct ucontext uc;
+	ucontext_t uc;
       } *rt_ = context->cfa;
       sc = &rt_->uc.uc_mcontext;
     }
Index: libgcc/config/bfin/linux-unwind.h
===================================================================
--- libgcc/config/bfin/linux-unwind.h	(revision 249686)
+++ libgcc/config/bfin/linux-unwind.h	(working copy)
@@ -52,7 +52,7 @@ bfin_fallback_frame_state (struct _Unwind_Context
 	void *puc;
 	char retcode[8];
 	siginfo_t info;
-	struct ucontext uc;
+	ucontext_t uc;
       } *rt_ = context->cfa;
 
       /* The void * cast is necessary to avoid an aliasing warning.
Index: libgcc/config/i386/linux-unwind.h
===================================================================
--- libgcc/config/i386/linux-unwind.h	(revision 249686)
+++ libgcc/config/i386/linux-unwind.h	(working copy)
@@ -58,7 +58,7 @@ x86_64_fallback_frame_state (struct _Unwind_Contex
   if (*(unsigned char *)(pc+0) == 0x48
       && *(unsigned long long *)(pc+1) == RT_SIGRETURN_SYSCALL)
     {
-      struct ucontext *uc_ = context->cfa;
+      ucontext_t *uc_ = context->cfa;
       /* The void * cast is necessary to avoid an aliasing warning.
          The aliasing warning is correct, but should not be a problem
          because it does not alias anything.  */
@@ -138,7 +138,7 @@ x86_fallback_frame_state (struct _Unwind_Context *
 	siginfo_t *pinfo;
 	void *puc;
 	siginfo_t info;
-	struct ucontext uc;
+	ucontext_t uc;
       } *rt_ = context->cfa;
       /* The void * cast is necessary to avoid an aliasing warning.
          The aliasing warning is correct, but should not be a problem
Index: libgcc/config/m68k/linux-unwind.h
===================================================================
--- libgcc/config/m68k/linux-unwind.h	(revision 249686)
+++ libgcc/config/m68k/linux-unwind.h	(working copy)
@@ -33,7 +33,7 @@ see the files COPYING3 and COPYING.RUNTIME respect
 /* <sys/ucontext.h> is unfortunately broken right now.  */
 struct uw_ucontext {
 	unsigned long	  uc_flags;
-	struct ucontext  *uc_link;
+	ucontext_t	 *uc_link;
 	stack_t		  uc_stack;
 	mcontext_t	  uc_mcontext;
 	unsigned long	  uc_filler[80];
Index: libgcc/config/nios2/linux-unwind.h
===================================================================
--- libgcc/config/nios2/linux-unwind.h	(revision 249686)
+++ libgcc/config/nios2/linux-unwind.h	(working copy)
@@ -38,7 +38,7 @@ struct nios2_mcontext {
 
 struct nios2_ucontext {
   unsigned long uc_flags;
-  struct ucontext *uc_link;
+  ucontext_t *uc_link;
   stack_t uc_stack;
   struct nios2_mcontext uc_mcontext;
   sigset_t uc_sigmask;	/* mask last for extensibility */
Index: libgcc/config/pa/linux-unwind.h
===================================================================
--- libgcc/config/pa/linux-unwind.h	(revision 249686)
+++ libgcc/config/pa/linux-unwind.h	(working copy)
@@ -80,7 +80,7 @@ pa32_fallback_frame_state (struct _Unwind_Context
   struct sigcontext *sc;
   struct rt_sigframe {
     siginfo_t info;
-    struct ucontext uc;
+    ucontext_t uc;
   } *frame;
 
   /* rt_sigreturn trampoline:
Index: libgcc/config/riscv/linux-unwind.h
===================================================================
--- libgcc/config/riscv/linux-unwind.h	(revision 249686)
+++ libgcc/config/riscv/linux-unwind.h	(working copy)
@@ -42,7 +42,7 @@ riscv_fallback_frame_state (struct _Unwind_Context
   struct rt_sigframe
   {
     siginfo_t info;
-    struct ucontext uc;
+    ucontext_t uc;
   };
 
   struct rt_sigframe *rt_;
Index: libgcc/config/sh/linux-unwind.h
===================================================================
--- libgcc/config/sh/linux-unwind.h	(revision 249686)
+++ libgcc/config/sh/linux-unwind.h	(working copy)
@@ -82,7 +82,7 @@ sh_fallback_frame_state (struct _Unwind_Context *c
     {
       struct rt_sigframe {
 	siginfo_t info;
-	struct ucontext uc;
+	ucontext_t uc;
       } *rt_ = context->cfa;
       /* The void * cast is necessary to avoid an aliasing warning.
          The aliasing warning is correct, but should not be a problem
Index: libgcc/config/tilepro/linux-unwind.h
===================================================================
--- libgcc/config/tilepro/linux-unwind.h	(revision 249686)
+++ libgcc/config/tilepro/linux-unwind.h	(working copy)
@@ -61,7 +61,7 @@ tile_fallback_frame_state (struct _Unwind_Context
   struct rt_sigframe {
     unsigned char save_area[C_ABI_SAVE_AREA_SIZE];
     siginfo_t info;
-    struct ucontext uc;
+    ucontext_t uc;
   } *rt_;
 
   /* Return if this is not a signal handler.  */
Index: libgcc/config/xtensa/linux-unwind.h
===================================================================
--- libgcc/config/xtensa/linux-unwind.h	(revision 249686)
+++ libgcc/config/xtensa/linux-unwind.h	(working copy)
@@ -67,7 +67,7 @@ xtensa_fallback_frame_state (struct _Unwind_Contex
 
   struct rt_sigframe {
     siginfo_t info;
-    struct ucontext uc;
+    ucontext_t uc;
   } *rt_;
 
   /* movi a2, __NR_rt_sigreturn; syscall */

-- 
Joseph S. Myers
joseph@codesourcery.com