Prepare for radical source tree reorganization.zack/build-layout-experiment

All top-level files and directories are moved into a temporary storage
directory, REORG.TODO, except for files that will certainly still
exist in their current form at top level when we're done (COPYING,
COPYING.LIB, LICENSES, NEWS, README), all old ChangeLog files (which
are moved to the new directory OldChangeLogs, instead), and the
generated file INSTALL (which is just deleted; in the new order, there
will be no generated files checked into version control).

1 files changed, 159 insertions, 0 deletions

diff --git a/REORG.TODO/sysdeps/sparc/backtrace.c b/REORG.TODO/sysdeps/sparc/backtrace.c
new file mode 100644
index 0000000000..2887031c72
--- /dev/null
+++ b/REORG.TODO/sysdeps/sparc/backtrace.c
@@ -0,0 +1,159 @@
+/* Return backtrace of current program state.
+   Copyright (C) 2013-2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by David S. Miller <davem@davemloft.net>
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#include <execinfo.h>
+#include <stddef.h>
+#include <sysdep.h>
+#include <sys/trap.h>
+#include <dlfcn.h>
+#include <unwind.h>
+#include <backtrace.h>
+
+struct layout
+{
+  unsigned long locals[8];
+  unsigned long ins[6];
+  unsigned long next;
+  void *return_address;
+};
+
+struct trace_arg
+{
+  void **array;
+  _Unwind_Word cfa;
+  int cnt;
+  int size;
+};
+
+#ifdef SHARED
+static _Unwind_Reason_Code (*unwind_backtrace) (_Unwind_Trace_Fn, void *);
+static _Unwind_Ptr (*unwind_getip) (struct _Unwind_Context *);
+static _Unwind_Word (*unwind_getcfa) (struct _Unwind_Context *);
+static void *libgcc_handle;
+
+/* Dummy version in case libgcc_s does not contain the real code.  */
+static _Unwind_Word
+dummy_getcfa (struct _Unwind_Context *ctx __attribute__ ((unused)))
+{
+  return 0;
+}
+
+static void
+init (void)
+{
+  libgcc_handle = __libc_dlopen ("libgcc_s.so.1");
+
+  if (libgcc_handle == NULL)
+    return;
+
+  unwind_backtrace = __libc_dlsym (libgcc_handle, "_Unwind_Backtrace");
+  unwind_getip = __libc_dlsym (libgcc_handle, "_Unwind_GetIP");
+  if (unwind_getip == NULL)
+    unwind_backtrace = NULL;
+  unwind_getcfa = (__libc_dlsym (libgcc_handle, "_Unwind_GetCFA")
+		  ?: dummy_getcfa);
+}
+#else
+# define unwind_backtrace _Unwind_Backtrace
+# define unwind_getip _Unwind_GetIP
+# define unwind_getcfa _Unwind_GetCFA
+#endif
+
+static _Unwind_Reason_Code
+backtrace_helper (struct _Unwind_Context *ctx, void *a)
+{
+  struct trace_arg *arg = a;
+  _Unwind_Ptr ip;
+
+  /* We are first called with address in the __backtrace function.
+     Skip it.  */
+  if (arg->cnt != -1)
+    {
+      ip = unwind_getip (ctx);
+      arg->array[arg->cnt] = (void *) ip;
+
+      /* Check whether we make any progress.  */
+      _Unwind_Word cfa = unwind_getcfa (ctx);
+
+      if (arg->cnt > 0 && arg->array[arg->cnt - 1] == arg->array[arg->cnt]
+	 && cfa == arg->cfa)
+       return _URC_END_OF_STACK;
+      arg->cfa = cfa;
+    }
+  if (++arg->cnt == arg->size)
+    return _URC_END_OF_STACK;
+  return _URC_NO_REASON;
+}
+
+int
+__backtrace (void **array, int size)
+{
+  struct trace_arg arg = { .array = array, .cfa = 0, .size = size, .cnt = -1 };
+  bool use_unwinder;
+  int count;
+
+  if (size <= 0)
+    return 0;
+
+  use_unwinder = true;
+#ifdef SHARED
+  __libc_once_define (static, once);
+
+  __libc_once (once, init);
+  if (unwind_backtrace == NULL)
+    use_unwinder = false;
+#endif
+
+  if (use_unwinder == false)
+    {
+      struct layout *current;
+      unsigned long fp, i7;
+
+      asm volatile ("mov %%fp, %0" : "=r"(fp));
+      asm volatile ("mov %%i7, %0" : "=r"(i7));
+      current = (struct layout *) (fp + BACKTRACE_STACK_BIAS);
+
+      array[0] = (void *) i7;
+
+      if (size == 1)
+	return 1;
+
+      backtrace_flush_register_windows();
+      for (count = 1; count < size; count++)
+	{
+	  array[count] = current->return_address;
+	  if (!current->next)
+	    break;
+	  current = (struct layout *) (current->next + BACKTRACE_STACK_BIAS);
+	}
+    }
+  else
+    {
+      unwind_backtrace (backtrace_helper, &arg);
+
+      /* _Unwind_Backtrace seems to put NULL address above
+	 _start.  Fix it up here.  */
+      if (arg.cnt > 1 && arg.array[arg.cnt - 1] == NULL)
+	--arg.cnt;
+      count = arg.cnt != -1 ? arg.cnt : 0;
+    }
+  return count;
+}
+weak_alias (__backtrace, backtrace)
+libc_hidden_def (__backtrace)