Branch data Line data Source code
1 : : /* Function return value location for Linux/PPC64 ABI.
2 : : Copyright (C) 2005-2010, 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 ppc64_
37 : : #include "libebl_CPU.h"
38 : :
39 : :
40 : : /* r3. */
41 : : static const Dwarf_Op loc_intreg[] =
42 : : {
43 : : { .atom = DW_OP_reg3 }
44 : : };
45 : : #define nloc_intreg 1
46 : :
47 : : /* f1, or f1:f2, or f1:f4. */
48 : : static const Dwarf_Op loc_fpreg[] =
49 : : {
50 : : { .atom = DW_OP_regx, .number = 33 }, { .atom = DW_OP_piece, .number = 8 },
51 : : { .atom = DW_OP_regx, .number = 34 }, { .atom = DW_OP_piece, .number = 8 },
52 : : { .atom = DW_OP_regx, .number = 35 }, { .atom = DW_OP_piece, .number = 8 },
53 : : { .atom = DW_OP_regx, .number = 36 }, { .atom = DW_OP_piece, .number = 8 },
54 : : };
55 : : #define nloc_fpreg 1
56 : : #define nloc_fp2regs 4
57 : : #define nloc_fp4regs 8
58 : :
59 : : /* vr2. */
60 : : static const Dwarf_Op loc_vmxreg[] =
61 : : {
62 : : { .atom = DW_OP_regx, .number = 1124 + 2 }
63 : : };
64 : : #define nloc_vmxreg 1
65 : :
66 : : /* The return value is a structure and is actually stored in stack space
67 : : passed in a hidden argument by the caller. But, the compiler
68 : : helpfully returns the address of that space in r3. */
69 : : static const Dwarf_Op loc_aggregate[] =
70 : : {
71 : : { .atom = DW_OP_breg3, .number = 0 }
72 : : };
73 : : #define nloc_aggregate 1
74 : :
75 : : int
76 : 0 : ppc64_return_value_location (Dwarf_Die *functypedie, const Dwarf_Op **locp)
77 : : {
78 : : /* Start with the function's type, and get the DW_AT_type attribute,
79 : : which is the type of the return value. */
80 : 0 : Dwarf_Die die_mem, *typedie = &die_mem;
81 : 0 : int tag = dwarf_peeled_die_type (functypedie, typedie);
82 [ # # ]: 0 : if (tag <= 0)
83 : : return tag;
84 : :
85 : 0 : Dwarf_Word size;
86 [ # # # # : 0 : switch (tag)
# # ]
87 : : {
88 : : case -1:
89 : : return -1;
90 : :
91 : 0 : case DW_TAG_subrange_type:
92 [ # # ]: 0 : if (! dwarf_hasattr_integrate (typedie, DW_AT_byte_size))
93 : : {
94 : 0 : Dwarf_Attribute attr_mem, *attr;
95 : 0 : attr = dwarf_attr_integrate (typedie, DW_AT_type, &attr_mem);
96 : 0 : typedie = dwarf_formref_die (attr, &die_mem);
97 [ # # ]: 0 : tag = DWARF_TAG_OR_RETURN (typedie);
98 : : }
99 : 0 : FALLTHROUGH;
100 : :
101 : : case DW_TAG_base_type:
102 : : case DW_TAG_enumeration_type:
103 : : CASE_POINTER:
104 : : {
105 : 0 : Dwarf_Attribute attr_mem;
106 [ # # ]: 0 : if (dwarf_formudata (dwarf_attr_integrate (typedie, DW_AT_byte_size,
107 : : &attr_mem), &size) != 0)
108 : : {
109 [ # # ]: 0 : if (dwarf_is_pointer (tag))
110 : 0 : size = 8;
111 : : else
112 : 0 : return -1;
113 : : }
114 : : }
115 : :
116 [ # # ]: 0 : if (tag == DW_TAG_base_type)
117 : : {
118 : 0 : Dwarf_Attribute attr_mem;
119 : 0 : Dwarf_Word encoding;
120 [ # # ]: 0 : if (dwarf_formudata (dwarf_attr_integrate (typedie, DW_AT_encoding,
121 : : &attr_mem),
122 : : &encoding) != 0)
123 : 0 : return -1;
124 : :
125 [ # # ]: 0 : if (encoding == DW_ATE_float || encoding == DW_ATE_complex_float)
126 : : {
127 : 0 : *locp = loc_fpreg;
128 [ # # ]: 0 : if (size <= 8)
129 : : return nloc_fpreg;
130 [ # # ]: 0 : if (size <= 16)
131 : : return nloc_fp2regs;
132 [ # # ]: 0 : if (size <= 32)
133 : : return nloc_fp4regs;
134 : : }
135 : : }
136 [ # # ]: 0 : if (size <= 8)
137 : : {
138 : 0 : intreg:
139 : 0 : *locp = loc_intreg;
140 : 0 : return nloc_intreg;
141 : : }
142 : :
143 : 0 : FALLTHROUGH;
144 : : case DW_TAG_structure_type:
145 : : case DW_TAG_class_type:
146 : : case DW_TAG_union_type:
147 : 0 : aggregate:
148 : 0 : *locp = loc_aggregate;
149 : 0 : return nloc_aggregate;
150 : :
151 : 0 : case DW_TAG_array_type:
152 : : {
153 : 0 : Dwarf_Attribute attr_mem;
154 : 0 : bool is_vector;
155 [ # # ]: 0 : if (dwarf_formflag (dwarf_attr_integrate (typedie, DW_AT_GNU_vector,
156 : : &attr_mem), &is_vector) == 0
157 [ # # ]: 0 : && is_vector)
158 : : {
159 : 0 : *locp = loc_vmxreg;
160 : 0 : return nloc_vmxreg;
161 : : }
162 : : }
163 : 0 : FALLTHROUGH;
164 : :
165 : : case DW_TAG_string_type:
166 [ # # # # ]: 0 : if (dwarf_aggregate_size (typedie, &size) == 0 && size <= 8)
167 : : {
168 [ # # ]: 0 : if (tag == DW_TAG_array_type)
169 : : {
170 : : /* Check if it's a character array. */
171 : 0 : Dwarf_Attribute attr_mem, *attr;
172 : 0 : attr = dwarf_attr_integrate (typedie, DW_AT_type, &attr_mem);
173 : 0 : typedie = dwarf_formref_die (attr, &die_mem);
174 [ # # ]: 0 : tag = DWARF_TAG_OR_RETURN (typedie);
175 [ # # ]: 0 : if (tag != DW_TAG_base_type)
176 : 0 : goto aggregate;
177 [ # # ]: 0 : if (dwarf_formudata (dwarf_attr_integrate (typedie,
178 : : DW_AT_byte_size,
179 : : &attr_mem),
180 : : &size) != 0)
181 : : return -1;
182 [ # # ]: 0 : if (size != 1)
183 : 0 : goto aggregate;
184 : : }
185 : 0 : goto intreg;
186 : : }
187 : 0 : goto aggregate;
188 : : }
189 : :
190 : : /* XXX We don't have a good way to return specific errors from ebl calls.
191 : : This value means we do not understand the type, but it is well-formed
192 : : DWARF and might be valid. */
193 : : return -2;
194 : : }
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