Nominal ARM support.
diff --git a/backends/arm_retval.c b/backends/arm_retval.c
new file mode 100644
index 0000000..4ffc6e7
--- /dev/null
+++ b/backends/arm_retval.c
@@ -0,0 +1,138 @@
+/* Function return value location for ARM EABI.
+ Copyright (C) 2009 Red Hat, Inc.
+ This file is part of Red Hat elfutils.
+
+ Red Hat elfutils is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by the
+ Free Software Foundation; version 2 of the License.
+
+ Red Hat 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 a copy of the GNU General Public License along
+ with Red Hat elfutils; if not, write to the Free Software Foundation,
+ Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA.
+
+ Red Hat elfutils is an included package of the Open Invention Network.
+ An included package of the Open Invention Network is a package for which
+ Open Invention Network licensees cross-license their patents. No patent
+ license is granted, either expressly or impliedly, by designation as an
+ included package. Should you wish to participate in the Open Invention
+ Network licensing program, please visit www.openinventionnetwork.com
+ <http://www.openinventionnetwork.com>. */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <assert.h>
+#include <dwarf.h>
+
+#define BACKEND arm_
+#include "libebl_CPU.h"
+
+
+/* r0, or pair r0, r1, or aggregate up to r0-r3. */
+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 },
+ { .atom = DW_OP_reg2 }, { .atom = DW_OP_piece, .number = 4 },
+ { .atom = DW_OP_reg3 }, { .atom = DW_OP_piece, .number = 4 },
+ };
+#define nloc_intreg 1
+#define nloc_intregs(n) (2 * (n))
+
+/* The return value is a structure and is actually stored in stack space
+ passed in a hidden argument by the caller. But, the compiler
+ helpfully returns the address of that space in r0. */
+static const Dwarf_Op loc_aggregate[] =
+ {
+ { .atom = DW_OP_breg0, .number = 0 }
+ };
+#define nloc_aggregate 1
+
+
+int
+arm_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_Attribute attr_mem;
+ Dwarf_Attribute *attr = dwarf_attr_integrate (functypedie, DW_AT_type,
+ &attr_mem);
+ if (attr == NULL)
+ /* The function has no return value, like a `void' function in C. */
+ return 0;
+
+ Dwarf_Die die_mem;
+ Dwarf_Die *typedie = dwarf_formref_die (attr, &die_mem);
+ int tag = dwarf_tag (typedie);
+
+ /* Follow typedefs and qualifiers to get to the actual type. */
+ while (tag == DW_TAG_typedef
+ || tag == DW_TAG_const_type || tag == DW_TAG_volatile_type
+ || tag == DW_TAG_restrict_type || tag == DW_TAG_mutable_type)
+ {
+ attr = dwarf_attr_integrate (typedie, DW_AT_type, &attr_mem);
+ typedie = dwarf_formref_die (attr, &die_mem);
+ tag = dwarf_tag (typedie);
+ }
+
+ Dwarf_Word size;
+ switch (tag)
+ {
+ case -1:
+ return -1;
+
+ case DW_TAG_subrange_type:
+ if (! dwarf_hasattr_integrate (typedie, DW_AT_byte_size))
+ {
+ attr = dwarf_attr_integrate (typedie, DW_AT_type, &attr_mem);
+ typedie = dwarf_formref_die (attr, &die_mem);
+ tag = dwarf_tag (typedie);
+ }
+ /* Fall through. */
+
+ case DW_TAG_base_type:
+ case DW_TAG_enumeration_type:
+ case DW_TAG_pointer_type:
+ case DW_TAG_ptr_to_member_type:
+ 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 <= 16)
+ {
+ intreg:
+ *locp = loc_intreg;
+ return size <= 4 ? nloc_intreg : nloc_intregs ((size + 3) / 4);
+ }
+
+ aggregate:
+ *locp = loc_aggregate;
+ return nloc_aggregate;
+
+ case DW_TAG_structure_type:
+ case DW_TAG_class_type:
+ case DW_TAG_union_type:
+ case DW_TAG_array_type:
+ if (dwarf_formudata (dwarf_attr_integrate (typedie, DW_AT_byte_size,
+ &attr_mem), &size) == 0
+ && size > 0 && size <= 4)
+ goto intreg;
+ goto aggregate;
+ }
+
+ /* 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;
+}