Branch data Line data Source code
1 : : /* Function return value location for Linux/SH ABI.
2 : : Copyright (C) 2010, 2014 Red Hat, Inc.
3 : : This file is part of elfutils.
4 : : Contributed by Matt Fleming <matt@console-pimps.org>.
5 : :
6 : : This file is free software; you can redistribute it and/or modify
7 : : it under the terms of either
8 : :
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
12 : :
13 : : or
14 : :
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
18 : :
19 : : or both in parallel, as here.
20 : :
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.
25 : :
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/>. */
29 : :
30 : : #ifdef HAVE_CONFIG_H
31 : : # include <config.h>
32 : : #endif
33 : :
34 : : #include <assert.h>
35 : : #include <dwarf.h>
36 : :
37 : : #define BACKEND sh_
38 : : #include "libebl_CPU.h"
39 : :
40 : :
41 : : /* This is the SVR4 ELF ABI convention, but AIX and Linux do not use it. */
42 : : #define SVR4_STRUCT_RETURN 0
43 : :
44 : :
45 : : /* r0, or pair r0, r1. */
46 : : static const Dwarf_Op loc_intreg[] =
47 : : {
48 : : { .atom = DW_OP_reg0 }, { .atom = DW_OP_piece, .number = 4 },
49 : : { .atom = DW_OP_reg1 }, { .atom = DW_OP_piece, .number = 4 },
50 : : };
51 : : #define nloc_intreg 1
52 : : #define nloc_intregpair 4
53 : :
54 : : /* fr0 or fr1. */
55 : : static const Dwarf_Op loc_fpreg[] =
56 : : {
57 : : { .atom = DW_OP_reg25 }, { .atom = DW_OP_piece, .number = 4 },
58 : : { .atom = DW_OP_reg26 }, { .atom = DW_OP_piece, .number = 4 },
59 : : };
60 : : #define nloc_fpreg 1
61 : : #define nloc_fpregpair 2
62 : :
63 : : int
64 : 0 : sh_return_value_location (Dwarf_Die *functypedie, const Dwarf_Op **locp)
65 : : {
66 : : /* Start with the function's type, and get the DW_AT_type attribute,
67 : : which is the type of the return value. */
68 : 0 : Dwarf_Die die_mem, *typedie = &die_mem;
69 : 0 : int tag = dwarf_peeled_die_type (functypedie, typedie);
70 [ # # ]: 0 : if (tag <= 0)
71 : : return tag;
72 : :
73 : 0 : Dwarf_Word size;
74 [ # # # ]: 0 : switch (tag)
75 : : {
76 : : case -1:
77 : : return -1;
78 : :
79 : 0 : case DW_TAG_subrange_type:
80 [ # # ]: 0 : if (! dwarf_hasattr_integrate (typedie, DW_AT_byte_size))
81 : : {
82 : 0 : Dwarf_Attribute attr_mem, *attr;
83 : 0 : attr = dwarf_attr_integrate (typedie, DW_AT_type, &attr_mem);
84 : 0 : typedie = dwarf_formref_die (attr, &die_mem);
85 [ # # ]: 0 : tag = DWARF_TAG_OR_RETURN (typedie);
86 : : }
87 : 0 : FALLTHROUGH;
88 : :
89 : : case DW_TAG_base_type:
90 : : case DW_TAG_enumeration_type:
91 : : case DW_TAG_pointer_type:
92 : : case DW_TAG_ptr_to_member_type:
93 : : {
94 : 0 : Dwarf_Attribute attr_mem;
95 [ # # ]: 0 : if (dwarf_formudata (dwarf_attr_integrate (typedie, DW_AT_byte_size,
96 : : &attr_mem), &size) != 0)
97 : : {
98 [ # # ]: 0 : if (tag == DW_TAG_pointer_type || tag == DW_TAG_ptr_to_member_type)
99 : 0 : size = 4;
100 : : else
101 : 0 : return -1;
102 : : }
103 : : }
104 : :
105 [ # # ]: 0 : if (size <= 8)
106 : : {
107 [ # # ]: 0 : if (tag == DW_TAG_base_type)
108 : : {
109 : 0 : Dwarf_Attribute attr_mem;
110 : 0 : Dwarf_Word encoding;
111 [ # # ]: 0 : if (dwarf_formudata (dwarf_attr_integrate (typedie,
112 : : DW_AT_encoding,
113 : : &attr_mem),
114 : : &encoding) != 0)
115 : 0 : return -1;
116 [ # # ]: 0 : if (encoding == DW_ATE_float)
117 : : {
118 : 0 : *locp = loc_fpreg;
119 [ # # ]: 0 : return size <= 4 ? nloc_fpreg : nloc_fpregpair;
120 : : }
121 : : }
122 : 0 : *locp = loc_intreg;
123 [ # # ]: 0 : return size <= 4 ? nloc_intreg : nloc_intregpair;
124 : : }
125 : : }
126 : :
127 : : /* XXX We don't have a good way to return specific errors from ebl calls.
128 : : This value means we do not understand the type, but it is well-formed
129 : : DWARF and might be valid. */
130 : : return -2;
131 : : }
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