Line data Source code
1 : /* Function return value location for SPARC.
2 : Copyright (C) 2006-2010, 2014 Red Hat, Inc.
3 : This file is part of elfutils.
4 :
5 : This file is free software; you can redistribute it and/or modify
6 : it under the terms of either
7 :
8 : * the GNU Lesser General Public License as published by the Free
9 : Software Foundation; either version 3 of the License, or (at
10 : your option) any later version
11 :
12 : or
13 :
14 : * the GNU General Public License as published by the Free
15 : Software Foundation; either version 2 of the License, or (at
16 : your option) any later version
17 :
18 : or both in parallel, as here.
19 :
20 : elfutils is distributed in the hope that it will be useful, but
21 : WITHOUT ANY WARRANTY; without even the implied warranty of
22 : MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
23 : General Public License for more details.
24 :
25 : You should have received copies of the GNU General Public License and
26 : the GNU Lesser General Public License along with this program. If
27 : not, see <http://www.gnu.org/licenses/>. */
28 :
29 : #ifdef HAVE_CONFIG_H
30 : # include <config.h>
31 : #endif
32 :
33 : #include <assert.h>
34 : #include <dwarf.h>
35 :
36 : #define BACKEND sparc_
37 : #include "libebl_CPU.h"
38 :
39 :
40 : /* %o0, or pair %o0, %o1. */
41 : static const Dwarf_Op loc_intreg[] =
42 : {
43 : { .atom = DW_OP_reg8 }, { .atom = DW_OP_piece, .number = 4 },
44 : { .atom = DW_OP_reg9 }, { .atom = DW_OP_piece, .number = 4 },
45 : };
46 : #define nloc_intreg 1
47 : #define nloc_intregpair 4
48 :
49 : /* %f0 or pair %f0, %f1, or quad %f0..%f3. */
50 : static const Dwarf_Op loc_fpreg[] =
51 : {
52 : { .atom = DW_OP_regx, .number = 32 }, { .atom = DW_OP_piece, .number = 4 },
53 : { .atom = DW_OP_regx, .number = 33 }, { .atom = DW_OP_piece, .number = 4 },
54 : { .atom = DW_OP_regx, .number = 34 }, { .atom = DW_OP_piece, .number = 4 },
55 : { .atom = DW_OP_regx, .number = 35 }, { .atom = DW_OP_piece, .number = 4 },
56 : };
57 : #define nloc_fpreg 1
58 : #define nloc_fpregpair 4
59 : #define nloc_fpregquad 8
60 :
61 : /* The return value is a structure and is actually stored in stack space
62 : passed in a hidden argument by the caller. But, the compiler
63 : helpfully returns the address of that space in %o0. */
64 : static const Dwarf_Op loc_aggregate[] =
65 : {
66 : { .atom = DW_OP_breg8, .number = 0 }
67 : };
68 : #define nloc_aggregate 1
69 :
70 : int
71 0 : sparc_return_value_location (Dwarf_Die *functypedie, const Dwarf_Op **locp)
72 : {
73 : /* Start with the function's type, and get the DW_AT_type attribute,
74 : which is the type of the return value. */
75 0 : Dwarf_Die die_mem, *typedie = &die_mem;
76 0 : int tag = dwarf_peeled_die_type (functypedie, typedie);
77 0 : if (tag <= 0)
78 : return tag;
79 :
80 0 : Dwarf_Word size;
81 0 : switch (tag)
82 : {
83 : case -1:
84 : return -1;
85 :
86 0 : case DW_TAG_subrange_type:
87 0 : if (! dwarf_hasattr_integrate (typedie, DW_AT_byte_size))
88 : {
89 0 : Dwarf_Attribute attr_mem, *attr;
90 0 : attr = dwarf_attr_integrate (typedie, DW_AT_type, &attr_mem);
91 0 : typedie = dwarf_formref_die (attr, &die_mem);
92 0 : tag = DWARF_TAG_OR_RETURN (typedie);
93 : }
94 0 : FALLTHROUGH;
95 :
96 : case DW_TAG_base_type:
97 : case DW_TAG_enumeration_type:
98 : case DW_TAG_pointer_type:
99 : case DW_TAG_ptr_to_member_type:
100 0 : {
101 0 : Dwarf_Attribute attr_mem;
102 0 : if (dwarf_formudata (dwarf_attr_integrate (typedie, DW_AT_byte_size,
103 : &attr_mem), &size) != 0)
104 : {
105 0 : uint8_t asize;
106 0 : Dwarf_Die cudie;
107 0 : if ((tag == DW_TAG_pointer_type || tag == DW_TAG_ptr_to_member_type)
108 0 : && dwarf_diecu (typedie, &cudie, &asize, NULL) != NULL)
109 0 : size = asize;
110 : else
111 0 : return -1;
112 : }
113 : }
114 :
115 0 : if (tag == DW_TAG_base_type)
116 : {
117 0 : Dwarf_Attribute attr_mem;
118 0 : Dwarf_Word encoding;
119 0 : if (dwarf_formudata (dwarf_attr_integrate (typedie, DW_AT_encoding,
120 : &attr_mem),
121 : &encoding) != 0)
122 0 : return -1;
123 0 : if (encoding == DW_ATE_float)
124 : {
125 0 : *locp = loc_fpreg;
126 0 : if (size <= 4)
127 : return nloc_fpreg;
128 0 : if (size <= 8)
129 : return nloc_fpregpair;
130 0 : if (size <= 16)
131 : return nloc_fpregquad;
132 : }
133 : }
134 0 : if (size <= 8)
135 : {
136 0 : intreg:
137 0 : *locp = loc_intreg;
138 0 : return size <= 4 ? nloc_intreg : nloc_intregpair;
139 : }
140 :
141 0 : aggregate:
142 0 : *locp = loc_aggregate;
143 0 : return nloc_aggregate;
144 :
145 0 : case DW_TAG_structure_type:
146 : case DW_TAG_class_type:
147 : case DW_TAG_union_type:
148 : case DW_TAG_array_type:
149 0 : if (dwarf_aggregate_size (typedie, &size) == 0
150 0 : && size > 0 && size <= 8)
151 : goto intreg;
152 : goto aggregate;
153 : }
154 :
155 : /* XXX We don't have a good way to return specific errors from ebl calls.
156 : This value means we do not understand the type, but it is well-formed
157 : DWARF and might be valid. */
158 0 : return -2;
159 : }
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