1 /* Function return value location for Linux/SH ABI.
2 Copyright (C) 2010 Red Hat, Inc.
3 This file is part of elfutils.
4 Contributed by Matt Fleming <matt@console-pimps.org>.
6 This file is free software; you can redistribute it and/or modify
7 it under the terms of either
9 * the GNU Lesser General Public License as published by the Free
10 Software Foundation; either version 3 of the License, or (at
11 your option) any later version
15 * the GNU General Public License as published by the Free
16 Software Foundation; either version 2 of the License, or (at
17 your option) any later version
19 or both in parallel, as here.
21 elfutils is distributed in the hope that it will be useful, but
22 WITHOUT ANY WARRANTY; without even the implied warranty of
23 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
24 General Public License for more details.
26 You should have received copies of the GNU General Public License and
27 the GNU Lesser General Public License along with this program. If
28 not, see <http://www.gnu.org/licenses/>. */
38 #include "libebl_CPU.h"
41 /* This is the SVR4 ELF ABI convention, but AIX and Linux do not use it. */
42 #define SVR4_STRUCT_RETURN 0
45 /* r0, or pair r0, r1. */
46 static const Dwarf_Op loc_intreg[] =
48 { .atom = DW_OP_reg0 }, { .atom = DW_OP_piece, .number = 4 },
49 { .atom = DW_OP_reg1 }, { .atom = DW_OP_piece, .number = 4 },
52 #define nloc_intregpair 4
55 static const Dwarf_Op loc_fpreg[] =
57 { .atom = DW_OP_reg25 }, { .atom = DW_OP_piece, .number = 4 },
58 { .atom = DW_OP_reg26 }, { .atom = DW_OP_piece, .number = 4 },
61 #define nloc_fpregpair 2
64 sh_return_value_location (Dwarf_Die *functypedie, const Dwarf_Op **locp)
66 /* Start with the function's type, and get the DW_AT_type attribute,
67 which is the type of the return value. */
69 Dwarf_Attribute attr_mem;
70 Dwarf_Attribute *attr = dwarf_attr_integrate (functypedie, DW_AT_type,
73 /* The function has no return value, like a `void' function in C. */
77 Dwarf_Die *typedie = dwarf_formref_die (attr, &die_mem);
78 int tag = dwarf_tag (typedie);
80 /* Follow typedefs and qualifiers to get to the actual type. */
81 while (tag == DW_TAG_typedef
82 || tag == DW_TAG_const_type || tag == DW_TAG_volatile_type
83 || tag == DW_TAG_restrict_type || tag == DW_TAG_mutable_type)
85 attr = dwarf_attr_integrate (typedie, DW_AT_type, &attr_mem);
86 typedie = dwarf_formref_die (attr, &die_mem);
87 tag = dwarf_tag (typedie);
96 case DW_TAG_subrange_type:
97 if (! dwarf_hasattr_integrate (typedie, DW_AT_byte_size))
99 attr = dwarf_attr_integrate (typedie, DW_AT_type, &attr_mem);
100 typedie = dwarf_formref_die (attr, &die_mem);
101 tag = dwarf_tag (typedie);
105 case DW_TAG_base_type:
106 case DW_TAG_enumeration_type:
107 case DW_TAG_pointer_type:
108 case DW_TAG_ptr_to_member_type:
109 if (dwarf_formudata (dwarf_attr_integrate (typedie, DW_AT_byte_size,
110 &attr_mem), &size) != 0)
112 if (tag == DW_TAG_pointer_type || tag == DW_TAG_ptr_to_member_type)
119 if (tag == DW_TAG_base_type)
122 if (dwarf_formudata (dwarf_attr_integrate (typedie,
127 if (encoding == DW_ATE_float)
130 return size <= 4 ? nloc_fpreg : nloc_fpregpair;
134 return size <= 4 ? nloc_intreg : nloc_intregpair;
138 /* XXX We don't have a good way to return specific errors from ebl calls.
139 This value means we do not understand the type, but it is well-formed
140 DWARF and might be valid. */