1 /* Routines for restoring various data types from a file stream. This deals
2 with various data types like strings, integers, enums, etc.
3
4 Copyright (C) 2011-2013 Free Software Foundation, Inc.
5 Contributed by Diego Novillo <dnovillo@google.com>
6
7 This file is part of GCC.
8
9 GCC is free software; you can redistribute it and/or modify it under
10 the terms of the GNU General Public License as published by the Free
11 Software Foundation; either version 3, or (at your option) any later
12 version.
13
14 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
15 WARRANTY; without even the implied warranty of MERCHANTABILITY or
16 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 for more details.
18
19 You should have received a copy of the GNU General Public License
20 along with GCC; see the file COPYING3. If not see
21 <http://www.gnu.org/licenses/>. */
22
23 #include "config.h"
24 #include "system.h"
25 #include "coretypes.h"
26 #include "diagnostic.h"
27 #include "data-streamer.h"
28
29 /* Read a string from the string table in DATA_IN using input block
30 IB. Write the length to RLEN. */
31
32 const char *
string_for_index(struct data_in * data_in,unsigned int loc,unsigned int * rlen)33 string_for_index (struct data_in *data_in, unsigned int loc, unsigned int *rlen)
34 {
35 struct lto_input_block str_tab;
36 unsigned int len;
37 const char *result;
38
39 if (!loc)
40 {
41 *rlen = 0;
42 return NULL;
43 }
44
45 /* Get the string stored at location LOC in DATA_IN->STRINGS. */
46 LTO_INIT_INPUT_BLOCK (str_tab, data_in->strings, loc - 1,
47 data_in->strings_len);
48 len = streamer_read_uhwi (&str_tab);
49 *rlen = len;
50
51 if (str_tab.p + len > data_in->strings_len)
52 internal_error ("bytecode stream: string too long for the string table");
53
54 result = (const char *)(data_in->strings + str_tab.p);
55
56 return result;
57 }
58
59
60 /* Read a string from the string table in DATA_IN using input block
61 IB. Write the length to RLEN. */
62
63 const char *
streamer_read_indexed_string(struct data_in * data_in,struct lto_input_block * ib,unsigned int * rlen)64 streamer_read_indexed_string (struct data_in *data_in,
65 struct lto_input_block *ib, unsigned int *rlen)
66 {
67 return string_for_index (data_in, streamer_read_uhwi (ib), rlen);
68 }
69
70
71 /* Read a NULL terminated string from the string table in DATA_IN. */
72
73 const char *
streamer_read_string(struct data_in * data_in,struct lto_input_block * ib)74 streamer_read_string (struct data_in *data_in, struct lto_input_block *ib)
75 {
76 unsigned int len;
77 const char *ptr;
78
79 ptr = streamer_read_indexed_string (data_in, ib, &len);
80 if (!ptr)
81 return NULL;
82 if (ptr[len - 1] != '\0')
83 internal_error ("bytecode stream: found non-null terminated string");
84
85 return ptr;
86 }
87
88
89 /* Read a string from the string table in DATA_IN using the bitpack BP.
90 Write the length to RLEN. */
91
92 const char *
bp_unpack_indexed_string(struct data_in * data_in,struct bitpack_d * bp,unsigned int * rlen)93 bp_unpack_indexed_string (struct data_in *data_in,
94 struct bitpack_d *bp, unsigned int *rlen)
95 {
96 return string_for_index (data_in, bp_unpack_var_len_unsigned (bp), rlen);
97 }
98
99
100 /* Read a NULL terminated string from the string table in DATA_IN. */
101
102 const char *
bp_unpack_string(struct data_in * data_in,struct bitpack_d * bp)103 bp_unpack_string (struct data_in *data_in, struct bitpack_d *bp)
104 {
105 unsigned int len;
106 const char *ptr;
107
108 ptr = bp_unpack_indexed_string (data_in, bp, &len);
109 if (!ptr)
110 return NULL;
111 if (ptr[len - 1] != '\0')
112 internal_error ("bytecode stream: found non-null terminated string");
113
114 return ptr;
115 }
116
117
118 /* Read an unsigned HOST_WIDE_INT number from IB. */
119
120 unsigned HOST_WIDE_INT
streamer_read_uhwi(struct lto_input_block * ib)121 streamer_read_uhwi (struct lto_input_block *ib)
122 {
123 unsigned HOST_WIDE_INT result = 0;
124 int shift = 0;
125 unsigned HOST_WIDE_INT byte;
126
127 while (true)
128 {
129 byte = streamer_read_uchar (ib);
130 result |= (byte & 0x7f) << shift;
131 shift += 7;
132 if ((byte & 0x80) == 0)
133 return result;
134 }
135 }
136
137
138 /* Read a HOST_WIDE_INT number from IB. */
139
140 HOST_WIDE_INT
streamer_read_hwi(struct lto_input_block * ib)141 streamer_read_hwi (struct lto_input_block *ib)
142 {
143 HOST_WIDE_INT result = 0;
144 int shift = 0;
145 unsigned HOST_WIDE_INT byte;
146
147 while (true)
148 {
149 byte = streamer_read_uchar (ib);
150 result |= (byte & 0x7f) << shift;
151 shift += 7;
152 if ((byte & 0x80) == 0)
153 {
154 if ((shift < HOST_BITS_PER_WIDE_INT) && (byte & 0x40))
155 result |= - ((HOST_WIDE_INT)1 << shift);
156
157 return result;
158 }
159 }
160 }
161