gcc/ChangeLog:
[official-gcc.git] / gcc / data-streamer-in.c
blobb38d91353fcf72d057f02488e4665a4cab35048a
1 /* Routines for restoring various data types from a file stream. This deals
2 with various data types like strings, integers, enums, etc.
4 Copyright (C) 2011-2017 Free Software Foundation, Inc.
5 Contributed by Diego Novillo <dnovillo@google.com>
7 This file is part of GCC.
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.
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.
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/>. */
23 #include "config.h"
24 #include "system.h"
25 #include "coretypes.h"
26 #include "backend.h"
27 #include "tree.h"
28 #include "gimple.h"
29 #include "cgraph.h"
30 #include "data-streamer.h"
32 /* Read a string from the string table in DATA_IN using input block
33 IB. Write the length to RLEN. */
35 static const char *
36 string_for_index (struct data_in *data_in, unsigned int loc, unsigned int *rlen)
38 unsigned int len;
39 const char *result;
41 if (!loc)
43 *rlen = 0;
44 return NULL;
47 /* Get the string stored at location LOC in DATA_IN->STRINGS. */
48 lto_input_block str_tab (data_in->strings, loc - 1, data_in->strings_len, NULL);
49 len = streamer_read_uhwi (&str_tab);
50 *rlen = len;
52 if (str_tab.p + len > data_in->strings_len)
53 internal_error ("bytecode stream: string too long for the string table");
55 result = (const char *)(data_in->strings + str_tab.p);
57 return result;
61 /* Read a string from the string table in DATA_IN using input block
62 IB. Write the length to RLEN. */
64 const char *
65 streamer_read_indexed_string (struct data_in *data_in,
66 struct lto_input_block *ib, unsigned int *rlen)
68 return string_for_index (data_in, streamer_read_uhwi (ib), rlen);
72 /* Read a NULL terminated string from the string table in DATA_IN. */
74 const char *
75 streamer_read_string (struct data_in *data_in, struct lto_input_block *ib)
77 unsigned int len;
78 const char *ptr;
80 ptr = streamer_read_indexed_string (data_in, ib, &len);
81 if (!ptr)
82 return NULL;
83 if (ptr[len - 1] != '\0')
84 internal_error ("bytecode stream: found non-null terminated string");
86 return ptr;
90 /* Read a string from the string table in DATA_IN using the bitpack BP.
91 Write the length to RLEN. */
93 const char *
94 bp_unpack_indexed_string (struct data_in *data_in,
95 struct bitpack_d *bp, unsigned int *rlen)
97 return string_for_index (data_in, bp_unpack_var_len_unsigned (bp), rlen);
101 /* Read a NULL terminated string from the string table in DATA_IN. */
103 const char *
104 bp_unpack_string (struct data_in *data_in, struct bitpack_d *bp)
106 unsigned int len;
107 const char *ptr;
109 ptr = bp_unpack_indexed_string (data_in, bp, &len);
110 if (!ptr)
111 return NULL;
112 if (ptr[len - 1] != '\0')
113 internal_error ("bytecode stream: found non-null terminated string");
115 return ptr;
119 /* Read an unsigned HOST_WIDE_INT number from IB. */
121 unsigned HOST_WIDE_INT
122 streamer_read_uhwi (struct lto_input_block *ib)
124 unsigned HOST_WIDE_INT result;
125 int shift;
126 unsigned HOST_WIDE_INT byte;
127 unsigned int p = ib->p;
128 unsigned int len = ib->len;
130 const char *data = ib->data;
131 result = data[p++];
132 if ((result & 0x80) != 0)
134 result &= 0x7f;
135 shift = 7;
138 byte = data[p++];
139 result |= (byte & 0x7f) << shift;
140 shift += 7;
142 while ((byte & 0x80) != 0);
145 /* We check for section overrun after the fact for performance reason. */
146 if (p > len)
147 lto_section_overrun (ib);
149 ib->p = p;
150 return result;
154 /* Read a HOST_WIDE_INT number from IB. */
156 HOST_WIDE_INT
157 streamer_read_hwi (struct lto_input_block *ib)
159 HOST_WIDE_INT result = 0;
160 int shift = 0;
161 unsigned HOST_WIDE_INT byte;
163 while (true)
165 byte = streamer_read_uchar (ib);
166 result |= (byte & 0x7f) << shift;
167 shift += 7;
168 if ((byte & 0x80) == 0)
170 if ((shift < HOST_BITS_PER_WIDE_INT) && (byte & 0x40))
171 result |= - (HOST_WIDE_INT_1U << shift);
173 return result;
178 /* Read gcov_type value from IB. */
180 gcov_type
181 streamer_read_gcov_count (struct lto_input_block *ib)
183 gcov_type ret = streamer_read_hwi (ib);
184 gcc_assert (ret >= 0);
185 return ret;
188 /* Read the physical representation of a wide_int val from
189 input block IB. */
191 wide_int
192 streamer_read_wide_int (struct lto_input_block *ib)
194 HOST_WIDE_INT a[WIDE_INT_MAX_ELTS];
195 int i;
196 int prec = streamer_read_uhwi (ib);
197 int len = streamer_read_uhwi (ib);
198 for (i = 0; i < len; i++)
199 a[i] = streamer_read_hwi (ib);
200 return wide_int::from_array (a, len, prec);
203 /* Read the physical representation of a widest_int val from
204 input block IB. */
206 widest_int
207 streamer_read_widest_int (struct lto_input_block *ib)
209 HOST_WIDE_INT a[WIDE_INT_MAX_ELTS];
210 int i;
211 int prec ATTRIBUTE_UNUSED = streamer_read_uhwi (ib);
212 int len = streamer_read_uhwi (ib);
213 for (i = 0; i < len; i++)
214 a[i] = streamer_read_hwi (ib);
215 return widest_int::from_array (a, len);