1 files changed, 125 insertions, 0 deletions
diff --git a/ports/sysdeps/arm/backtrace.c b/ports/sysdeps/arm/backtrace.c
new file mode 100644
index 0000000000..3d839e628c
--- /dev/null
+++ b/ports/sysdeps/arm/backtrace.c
@@ -0,0 +1,125 @@
+/* Return backtrace of current program state.
+   Copyright (C) 2008, 2009 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Kazu Hirata <kazu@codesourcery.com>, 2008.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library.  If not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <bits/libc-lock.h>
+#include <dlfcn.h>
+#include <execinfo.h>
+#include <stdlib.h>
+#include <unwind.h>
+
+struct trace_arg
+{
+  void **array;
+  int cnt, size;
+};
+
+#ifdef SHARED
+static _Unwind_Reason_Code (*unwind_backtrace) (_Unwind_Trace_Fn, void *);
+static _Unwind_VRS_Result (*unwind_vrs_get) (_Unwind_Context *,
+					     _Unwind_VRS_RegClass,
+					     _uw,
+					     _Unwind_VRS_DataRepresentation,
+					     void *);
+
+static void *libgcc_handle;
+
+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_vrs_get = __libc_dlsym (libgcc_handle, "_Unwind_VRS_Get");
+  if (unwind_vrs_get == NULL)
+    unwind_backtrace = NULL;
+}
+
+/* This function is identical to "_Unwind_GetGR", except that it uses
+   "unwind_vrs_get" instead of "_Unwind_VRS_Get".  */
+static inline _Unwind_Word
+unwind_getgr (_Unwind_Context *context, int regno)
+{
+  _uw val;
+  unwind_vrs_get (context, _UVRSC_CORE, regno, _UVRSD_UINT32, &val);
+  return val;
+}
+
+/* This macro is identical to the _Unwind_GetIP macro, except that it
+   uses "unwind_getgr" instead of "_Unwind_GetGR".  */
+# define unwind_getip(context) \
+  (unwind_getgr (context, 15) & ~(_Unwind_Word)1)
+#else
+# define unwind_backtrace _Unwind_Backtrace
+# define unwind_getip _Unwind_GetIP
+#endif
+
+static _Unwind_Reason_Code
+backtrace_helper (struct _Unwind_Context *ctx, void *a)
+{
+  struct trace_arg *arg = a;
+
+  /* We are first called with address in the __backtrace function.
+     Skip it.  */
+  if (arg->cnt != -1)
+    arg->array[arg->cnt] = (void *) unwind_getip (ctx);
+  if (++arg->cnt == arg->size)
+    return _URC_END_OF_STACK;
+  return _URC_NO_REASON;
+}
+
+int
+__backtrace (array, size)
+     void **array;
+     int size;
+{
+  struct trace_arg arg = { .array = array, .size = size, .cnt = -1 };
+#ifdef SHARED
+  __libc_once_define (static, once);
+
+  __libc_once (once, init);
+  if (unwind_backtrace == NULL)
+    return 0;
+#endif
+
+  if (size >= 1)
+    unwind_backtrace (backtrace_helper, &arg);
+
+  if (arg.cnt > 1 && arg.array[arg.cnt - 1] == NULL)
+    --arg.cnt;
+  return arg.cnt != -1 ? arg.cnt : 0;
+}
+weak_alias (__backtrace, backtrace)
+libc_hidden_def (__backtrace)
+
+
+#ifdef SHARED
+/* Free all resources if necessary.  */
+libc_freeres_fn (free_mem)
+{
+  unwind_backtrace = NULL;
+  if (libgcc_handle != NULL)
+    {
+      __libc_dlclose (libgcc_handle);
+      libgcc_handle = NULL;
+    }
+}
+#endif