Squashed 'third_party/elfutils/' content from commit 555e15e

Change-Id: I61cde98949e47e5c8c09c33260de17f30921be79
git-subtree-dir: third_party/elfutils
git-subtree-split: 555e15ebe8bf1eb33d00747173cfc80cc65648a4
diff --git a/backends/sh_retval.c b/backends/sh_retval.c
new file mode 100644
index 0000000..33d7d96
--- /dev/null
+++ b/backends/sh_retval.c
@@ -0,0 +1,131 @@
+/* Function return value location for Linux/SH ABI.
+   Copyright (C) 2010, 2014 Red Hat, Inc.
+   This file is part of elfutils.
+   Contributed by Matt Fleming <matt@console-pimps.org>.
+
+   This file is free software; you can redistribute it and/or modify
+   it under the terms of either
+
+     * the GNU Lesser General Public License as published by the Free
+       Software Foundation; either version 3 of the License, or (at
+       your option) any later version
+
+   or
+
+     * the GNU General Public License as published by the Free
+       Software Foundation; either version 2 of the License, or (at
+       your option) any later version
+
+   or both in parallel, as here.
+
+   elfutils 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
+   General Public License for more details.
+
+   You should have received copies of the GNU General Public License and
+   the GNU Lesser General Public License along with this program.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <assert.h>
+#include <dwarf.h>
+
+#define BACKEND sh_
+#include "libebl_CPU.h"
+
+
+/* This is the SVR4 ELF ABI convention, but AIX and Linux do not use it.  */
+#define SVR4_STRUCT_RETURN 0
+
+
+/* r0, or pair r0, r1.  */
+static const Dwarf_Op loc_intreg[] =
+  {
+    { .atom = DW_OP_reg0 }, { .atom = DW_OP_piece, .number = 4 },
+    { .atom = DW_OP_reg1 }, { .atom = DW_OP_piece, .number = 4 },
+  };
+#define nloc_intreg	1
+#define nloc_intregpair	4
+
+/* fr0 or fr1.  */
+static const Dwarf_Op loc_fpreg[] =
+  {
+    { .atom = DW_OP_reg25 }, { .atom = DW_OP_piece, .number = 4 },
+    { .atom = DW_OP_reg26 }, { .atom = DW_OP_piece, .number = 4 },
+  };
+#define nloc_fpreg	1
+#define nloc_fpregpair	2
+
+int
+sh_return_value_location (Dwarf_Die *functypedie, const Dwarf_Op **locp)
+{
+  /* Start with the function's type, and get the DW_AT_type attribute,
+     which is the type of the return value.  */
+  Dwarf_Die die_mem, *typedie = &die_mem;
+  int tag = dwarf_peeled_die_type (functypedie, typedie);
+  if (tag <= 0)
+    return tag;
+
+  Dwarf_Word size;
+  switch (tag)
+    {
+    case -1:
+      return -1;
+
+    case DW_TAG_subrange_type:
+      if (! dwarf_hasattr_integrate (typedie, DW_AT_byte_size))
+	{
+	  Dwarf_Attribute attr_mem, *attr;
+	  attr = dwarf_attr_integrate (typedie, DW_AT_type, &attr_mem);
+	  typedie = dwarf_formref_die (attr, &die_mem);
+	  tag = DWARF_TAG_OR_RETURN (typedie);
+	}
+      FALLTHROUGH;
+
+    case DW_TAG_base_type:
+    case DW_TAG_enumeration_type:
+    case DW_TAG_pointer_type:
+    case DW_TAG_ptr_to_member_type:
+      {
+	Dwarf_Attribute attr_mem;
+	if (dwarf_formudata (dwarf_attr_integrate (typedie, DW_AT_byte_size,
+						   &attr_mem), &size) != 0)
+	  {
+	    if (tag == DW_TAG_pointer_type || tag == DW_TAG_ptr_to_member_type)
+	      size = 4;
+	    else
+	      return -1;
+	  }
+      }
+
+      if (size <= 8)
+	{
+	  if (tag == DW_TAG_base_type)
+	    {
+	      Dwarf_Attribute attr_mem;
+	      Dwarf_Word encoding;
+	      if (dwarf_formudata (dwarf_attr_integrate (typedie,
+							 DW_AT_encoding,
+							 &attr_mem),
+				   &encoding) != 0)
+		return -1;
+	      if (encoding == DW_ATE_float)
+		{
+		  *locp = loc_fpreg;
+		  return size <= 4 ? nloc_fpreg : nloc_fpregpair;
+		}
+	    }
+	  *locp = loc_intreg;
+	  return size <= 4 ? nloc_intreg : nloc_intregpair;
+	}
+    }
+
+  /* XXX We don't have a good way to return specific errors from ebl calls.
+     This value means we do not understand the type, but it is well-formed
+     DWARF and might be valid.  */
+  return -2;
+}