gcc/5.4.0: use 'ucontext_t' instead of 'ucontext', bug #629502

Fixes one of build failures against glibc-2.26:

  ./md-unwind-support.h: In function 'x86_64_fallback_frame_state':
  ./md-unwind-support.h:65:47: error: dereferencing pointer to incomplete type 'struct ucontext'
         sc = (struct sigcontext *) (void *) &uc_->uc_mcontext;
                                                 ^~

Bug: https://bugs.gentoo.org/629502

2 files changed, 193 insertions, 0 deletions

diff --git a/src/patchsets/gcc/5.4.0/gentoo/93_all_ucontext-to-ucontext_t.patch b/src/patchsets/gcc/5.4.0/gentoo/93_all_ucontext-to-ucontext_t.patch
new file mode 100644
index 0000000000..4da66e837f
--- /dev/null
+++ b/src/patchsets/gcc/5.4.0/gentoo/93_all_ucontext-to-ucontext_t.patch
@@ -0,0 +1,191 @@
+https://bugs.gentoo.org/629502
+
+From ecf0d1a107133c715763940c2b197aa814710e1b Mon Sep 17 00:00:00 2001
+From: jsm28 <jsm28@138bc75d-0d04-0410-961f-82ee72b054a4>
+Date: Tue, 4 Jul 2017 10:25:10 +0000
+Subject: [PATCH] Use ucontext_t not struct ucontext in linux-unwind.h files.
+
+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.
+
+Tested compilation together with current glibc with glibc's
+build-many-glibcs.py.
+
+	* 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/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.
+
+
+git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/gcc-5-branch@249958 138bc75d-0d04-0410-961f-82ee72b054a4
+---
+ libgcc/config/aarch64/linux-unwind.h |  2 +-
+ libgcc/config/alpha/linux-unwind.h   |  2 +-
+ libgcc/config/bfin/linux-unwind.h    |  2 +-
+ libgcc/config/i386/linux-unwind.h    |  4 ++--
+ libgcc/config/m68k/linux-unwind.h    |  2 +-
+ libgcc/config/nios2/linux-unwind.h   |  2 +-
+ libgcc/config/pa/linux-unwind.h      |  2 +-
+ libgcc/config/sh/linux-unwind.h      |  2 +-
+ libgcc/config/tilepro/linux-unwind.h |  2 +-
+ libgcc/config/xtensa/linux-unwind.h  |  2 +-
+ 11 files changed, 25 insertions(+), 11 deletions(-)
+
+diff --git a/libgcc/config/aarch64/linux-unwind.h b/libgcc/config/aarch64/linux-unwind.h
+index 86d17b1c798..909f68f7311 100644
+--- a/libgcc/config/aarch64/linux-unwind.h
++++ b/libgcc/config/aarch64/linux-unwind.h
+@@ -52,7 +52,7 @@ aarch64_fallback_frame_state (struct _Unwind_Context *context,
+   struct rt_sigframe
+   {
+     siginfo_t info;
+-    struct ucontext uc;
++    ucontext_t uc;
+   };
+ 
+   struct rt_sigframe *rt_;
+diff --git a/libgcc/config/alpha/linux-unwind.h b/libgcc/config/alpha/linux-unwind.h
+index d65474fec12..9a226b195b5 100644
+--- a/libgcc/config/alpha/linux-unwind.h
++++ b/libgcc/config/alpha/linux-unwind.h
+@@ -51,7 +51,7 @@ alpha_fallback_frame_state (struct _Unwind_Context *context,
+     {
+       struct rt_sigframe {
+ 	siginfo_t info;
+-	struct ucontext uc;
++	ucontext_t uc;
+       } *rt_ = context->cfa;
+       sc = &rt_->uc.uc_mcontext;
+     }
+diff --git a/libgcc/config/bfin/linux-unwind.h b/libgcc/config/bfin/linux-unwind.h
+index 0c270e435c7..7fa95d2dc96 100644
+--- a/libgcc/config/bfin/linux-unwind.h
++++ b/libgcc/config/bfin/linux-unwind.h
+@@ -52,7 +52,7 @@ bfin_fallback_frame_state (struct _Unwind_Context *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.
+diff --git a/libgcc/config/i386/linux-unwind.h b/libgcc/config/i386/linux-unwind.h
+index e54bf73b1fd..d35fc4566ce 100644
+--- a/libgcc/config/i386/linux-unwind.h
++++ b/libgcc/config/i386/linux-unwind.h
+@@ -58,7 +58,7 @@ x86_64_fallback_frame_state (struct _Unwind_Context *context,
+   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 *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
+diff --git a/libgcc/config/m68k/linux-unwind.h b/libgcc/config/m68k/linux-unwind.h
+index fb79a4d63cd..b2f5ea4cd7c 100644
+--- a/libgcc/config/m68k/linux-unwind.h
++++ b/libgcc/config/m68k/linux-unwind.h
+@@ -33,7 +33,7 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+ /* <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];
+diff --git a/libgcc/config/nios2/linux-unwind.h b/libgcc/config/nios2/linux-unwind.h
+index dff1c20076e..1d88afecb12 100644
+--- a/libgcc/config/nios2/linux-unwind.h
++++ b/libgcc/config/nios2/linux-unwind.h
+@@ -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 */
+diff --git a/libgcc/config/pa/linux-unwind.h b/libgcc/config/pa/linux-unwind.h
+index 01494685ea4..91575356803 100644
+--- a/libgcc/config/pa/linux-unwind.h
++++ b/libgcc/config/pa/linux-unwind.h
+@@ -80,7 +80,7 @@ pa32_fallback_frame_state (struct _Unwind_Context *context,
+   struct sigcontext *sc;
+   struct rt_sigframe {
+     siginfo_t info;
+-    struct ucontext uc;
++    ucontext_t uc;
+   } *frame;
+ 
+   /* rt_sigreturn trampoline:
+diff --git a/libgcc/config/sh/linux-unwind.h b/libgcc/config/sh/linux-unwind.h
+index e63091f287c..67033f06b4b 100644
+--- a/libgcc/config/sh/linux-unwind.h
++++ b/libgcc/config/sh/linux-unwind.h
+@@ -180,7 +180,7 @@ sh_fallback_frame_state (struct _Unwind_Context *context,
+     {
+       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
+diff --git a/libgcc/config/tilepro/linux-unwind.h b/libgcc/config/tilepro/linux-unwind.h
+index fd83ba7c275..e3c9ef0840d 100644
+--- a/libgcc/config/tilepro/linux-unwind.h
++++ b/libgcc/config/tilepro/linux-unwind.h
+@@ -61,7 +61,7 @@ tile_fallback_frame_state (struct _Unwind_Context *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.  */
+diff --git a/libgcc/config/xtensa/linux-unwind.h b/libgcc/config/xtensa/linux-unwind.h
+index 9a67b5d2b46..98b7ea60e81 100644
+--- a/libgcc/config/xtensa/linux-unwind.h
++++ b/libgcc/config/xtensa/linux-unwind.h
+@@ -67,7 +67,7 @@ xtensa_fallback_frame_state (struct _Unwind_Context *context,
+ 
+   struct rt_sigframe {
+     siginfo_t info;
+-    struct ucontext uc;
++    ucontext_t uc;
+   } *rt_;
+ 
+   /* movi a2, __NR_rt_sigreturn; syscall */
+-- 
+2.14.1
+
diff --git a/src/patchsets/gcc/5.4.0/gentoo/README.history b/src/patchsets/gcc/5.4.0/gentoo/README.history
index 21bbb7a031..ef6c8e64b7 100644
--- a/src/patchsets/gcc/5.4.0/gentoo/README.history
+++ b/src/patchsets/gcc/5.4.0/gentoo/README.history
@@ -1,3 +1,5 @@
+1.6		26 Oct 2017
+	+ 93_all_ucontext-to-ucontext_t.patch
 1.5		24 Oct 2017
 	+ 92_all_asan-signal_h.patch
 1.4		06 Aug 2017