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44acf429 | 1 | /* String pool for GCC. |
71e45bc2 | 2 | Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009, 2010, |
3 | 2012 Free Software Foundation, Inc. | |
44acf429 | 4 | |
f12b58b3 | 5 | This file is part of GCC. |
44acf429 | 6 | |
f12b58b3 | 7 | GCC is free software; you can redistribute it and/or modify it under |
8 | the terms of the GNU General Public License as published by the Free | |
8c4c00c1 | 9 | Software Foundation; either version 3, or (at your option) any later |
f12b58b3 | 10 | version. |
44acf429 | 11 | |
f12b58b3 | 12 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY |
13 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
44acf429 | 14 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
15 | for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
8c4c00c1 | 18 | along with GCC; see the file COPYING3. If not see |
19 | <http://www.gnu.org/licenses/>. */ | |
44acf429 | 20 | |
83f43f36 | 21 | /* String text, identifier text and identifier node allocator. |
22 | Identifiers are uniquely stored in a hash table. | |
44acf429 | 23 | |
d856c8a6 | 24 | We use cpplib's hash table implementation. libiberty's |
0d086e18 | 25 | hashtab.c is not used because it requires 100% average space |
26 | overhead per string, which is unacceptable. Also, this algorithm | |
27 | is faster. */ | |
44acf429 | 28 | |
29 | #include "config.h" | |
30 | #include "system.h" | |
805e22b2 | 31 | #include "coretypes.h" |
44acf429 | 32 | #include "ggc.h" |
ba72912a | 33 | #include "ggc-internal.h" |
44acf429 | 34 | #include "tree.h" |
d856c8a6 | 35 | #include "symtab.h" |
78e9fc50 | 36 | #include "cpplib.h" |
44acf429 | 37 | |
38 | /* The "" allocated string. */ | |
39 | const char empty_string[] = ""; | |
40 | ||
ec6cb94a | 41 | /* Character strings, each containing a single decimal digit. |
42 | Written this way to save space. */ | |
ba72912a | 43 | static const char digit_vector[] = { |
ec6cb94a | 44 | '0', 0, '1', 0, '2', 0, '3', 0, '4', 0, |
45 | '5', 0, '6', 0, '7', 0, '8', 0, '9', 0 | |
46 | }; | |
47 | ||
ba72912a | 48 | #define digit_string(d) (digit_vector + ((d) * 2)) |
49 | ||
0d086e18 | 50 | struct ht *ident_hash; |
44acf429 | 51 | |
2b15d2ba | 52 | static hashnode alloc_node (cpp_hash_table *); |
60b8c5b3 | 53 | static int mark_ident (struct cpp_reader *, hashnode, const void *); |
c39ed964 | 54 | |
55 | static void * | |
56 | stringpool_ggc_alloc (size_t x) | |
57 | { | |
ba72912a | 58 | return ggc_alloc_atomic (x); |
c39ed964 | 59 | } |
0d086e18 | 60 | |
44acf429 | 61 | /* Initialize the string pool. */ |
62 | void | |
60b8c5b3 | 63 | init_stringpool (void) |
44acf429 | 64 | { |
0d086e18 | 65 | /* Create with 16K (2^14) entries. */ |
66 | ident_hash = ht_create (14); | |
67 | ident_hash->alloc_node = alloc_node; | |
c39ed964 | 68 | ident_hash->alloc_subobject = stringpool_ggc_alloc; |
44acf429 | 69 | } |
70 | ||
0d086e18 | 71 | /* Allocate a hash node. */ |
72 | static hashnode | |
2b15d2ba | 73 | alloc_node (cpp_hash_table *table ATTRIBUTE_UNUSED) |
44acf429 | 74 | { |
0d086e18 | 75 | return GCC_IDENT_TO_HT_IDENT (make_node (IDENTIFIER_NODE)); |
44acf429 | 76 | } |
77 | ||
78 | /* Allocate and return a string constant of length LENGTH, containing | |
79 | CONTENTS. If LENGTH is -1, CONTENTS is assumed to be a | |
83f43f36 | 80 | nul-terminated string, and the length is calculated using strlen. */ |
44acf429 | 81 | |
82 | const char * | |
ba72912a | 83 | ggc_alloc_string_stat (const char *contents, int length MEM_STAT_DECL) |
44acf429 | 84 | { |
dfecde36 | 85 | char *result; |
86 | ||
44acf429 | 87 | if (length == -1) |
88 | length = strlen (contents); | |
89 | ||
90 | if (length == 0) | |
91 | return empty_string; | |
66a33570 | 92 | if (length == 1 && ISDIGIT (contents[0])) |
ec6cb94a | 93 | return digit_string (contents[0] - '0'); |
44acf429 | 94 | |
ba72912a | 95 | result = (char *) ggc_alloc_atomic_stat (length + 1 PASS_MEM_STAT); |
83f43f36 | 96 | memcpy (result, contents, length); |
97 | result[length] = '\0'; | |
dfecde36 | 98 | return (const char *) result; |
44acf429 | 99 | } |
100 | ||
101 | /* Return an IDENTIFIER_NODE whose name is TEXT (a null-terminated string). | |
102 | If an identifier with that name has previously been referred to, | |
103 | the same node is returned this time. */ | |
0d086e18 | 104 | |
69642df2 | 105 | #undef get_identifier |
106 | ||
44acf429 | 107 | tree |
60b8c5b3 | 108 | get_identifier (const char *text) |
44acf429 | 109 | { |
0d086e18 | 110 | hashnode ht_node = ht_lookup (ident_hash, |
111 | (const unsigned char *) text, | |
112 | strlen (text), HT_ALLOC); | |
1e5bfc66 | 113 | |
0d086e18 | 114 | /* ht_node can't be NULL here. */ |
115 | return HT_IDENT_TO_GCC_IDENT (ht_node); | |
44acf429 | 116 | } |
117 | ||
82863d5e | 118 | /* Identical to get_identifier, except that the length is assumed |
119 | known. */ | |
40734805 | 120 | |
82863d5e | 121 | tree |
69642df2 | 122 | get_identifier_with_length (const char *text, size_t length) |
82863d5e | 123 | { |
124 | hashnode ht_node = ht_lookup (ident_hash, | |
125 | (const unsigned char *) text, | |
126 | length, HT_ALLOC); | |
127 | ||
128 | /* ht_node can't be NULL here. */ | |
129 | return HT_IDENT_TO_GCC_IDENT (ht_node); | |
130 | } | |
131 | ||
44acf429 | 132 | /* If an identifier with the name TEXT (a null-terminated string) has |
133 | previously been referred to, return that node; otherwise return | |
134 | NULL_TREE. */ | |
135 | ||
136 | tree | |
60b8c5b3 | 137 | maybe_get_identifier (const char *text) |
44acf429 | 138 | { |
0d086e18 | 139 | hashnode ht_node; |
44acf429 | 140 | |
0d086e18 | 141 | ht_node = ht_lookup (ident_hash, (const unsigned char *) text, |
17822ef8 | 142 | strlen (text), HT_NO_INSERT); |
0d086e18 | 143 | if (ht_node) |
17822ef8 | 144 | return HT_IDENT_TO_GCC_IDENT (ht_node); |
44acf429 | 145 | |
1e5bfc66 | 146 | return NULL_TREE; |
e2df8b81 | 147 | } |
148 | ||
44acf429 | 149 | /* Report some basic statistics about the string pool. */ |
150 | ||
151 | void | |
60b8c5b3 | 152 | stringpool_statistics (void) |
44acf429 | 153 | { |
0d086e18 | 154 | ht_dump_statistics (ident_hash); |
44acf429 | 155 | } |
5b916b55 | 156 | \f |
0d086e18 | 157 | /* Mark an identifier for GC. */ |
44acf429 | 158 | |
0d086e18 | 159 | static int |
60b8c5b3 | 160 | mark_ident (struct cpp_reader *pfile ATTRIBUTE_UNUSED, hashnode h, |
161 | const void *v ATTRIBUTE_UNUSED) | |
44acf429 | 162 | { |
573aba85 | 163 | gt_ggc_m_9tree_node (HT_IDENT_TO_GCC_IDENT (h)); |
0d086e18 | 164 | return 1; |
165 | } | |
44acf429 | 166 | |
dfecde36 | 167 | /* Return true if an identifier should be removed from the table. */ |
168 | ||
169 | static int | |
170 | maybe_delete_ident (struct cpp_reader *pfile ATTRIBUTE_UNUSED, hashnode h, | |
171 | const void *v ATTRIBUTE_UNUSED) | |
172 | { | |
173 | return !ggc_marked_p (HT_IDENT_TO_GCC_IDENT (h)); | |
174 | } | |
175 | ||
573aba85 | 176 | /* Mark the trees hanging off the identifier node for GGC. These are |
dfecde36 | 177 | handled specially (not using gengtype) because identifiers are only |
178 | roots during one part of compilation. */ | |
0d086e18 | 179 | |
573aba85 | 180 | void |
60b8c5b3 | 181 | ggc_mark_stringpool (void) |
0d086e18 | 182 | { |
183 | ht_forall (ident_hash, mark_ident, NULL); | |
44acf429 | 184 | } |
573aba85 | 185 | |
dfecde36 | 186 | /* Purge the identifier hash of identifiers which are no longer |
187 | referenced. */ | |
573aba85 | 188 | |
189 | void | |
dfecde36 | 190 | ggc_purge_stringpool (void) |
573aba85 | 191 | { |
dfecde36 | 192 | ht_purge (ident_hash, maybe_delete_ident, NULL); |
573aba85 | 193 | } |
194 | ||
195 | /* Pointer-walking routine for strings (not very interesting, since | |
196 | strings don't contain pointers). */ | |
197 | ||
198 | void | |
60b8c5b3 | 199 | gt_pch_p_S (void *obj ATTRIBUTE_UNUSED, void *x ATTRIBUTE_UNUSED, |
200 | gt_pointer_operator op ATTRIBUTE_UNUSED, | |
201 | void *cookie ATTRIBUTE_UNUSED) | |
573aba85 | 202 | { |
203 | } | |
204 | ||
205 | /* PCH pointer-walking routine for strings. */ | |
206 | ||
207 | void | |
60b8c5b3 | 208 | gt_pch_n_S (const void *x) |
573aba85 | 209 | { |
f7f3687c | 210 | gt_pch_note_object (CONST_CAST (void *, x), CONST_CAST (void *, x), |
211 | >_pch_p_S, gt_types_enum_last); | |
573aba85 | 212 | } |
2b15d2ba | 213 | |
214 | ||
215 | /* User-callable entry point for marking string X. */ | |
216 | ||
217 | void | |
218 | gt_pch_nx (const char *& x) | |
219 | { | |
220 | gt_pch_n_S (x); | |
221 | } | |
222 | ||
223 | void | |
224 | gt_pch_nx (unsigned char *& x) | |
225 | { | |
226 | gt_pch_n_S (x); | |
227 | } | |
228 | ||
229 | void | |
230 | gt_pch_nx (unsigned char& x ATTRIBUTE_UNUSED) | |
231 | { | |
232 | } | |
233 | ||
234 | void | |
235 | gt_pch_nx (unsigned char *x, gt_pointer_operator op, void *cookie) | |
236 | { | |
237 | op (x, cookie); | |
238 | } | |
5b916b55 | 239 | \f |
573aba85 | 240 | /* Handle saving and restoring the string pool for PCH. */ |
241 | ||
5b916b55 | 242 | /* SPD is saved in the PCH file and holds the information needed |
243 | to restore the string pool. */ | |
244 | ||
fb1e4f4a | 245 | struct GTY(()) string_pool_data { |
ba72912a | 246 | ht_identifier_ptr * |
8ed01400 | 247 | GTY((length ("%h.nslots"), |
248 | nested_ptr (union tree_node, "%h ? GCC_IDENT_TO_HT_IDENT (%h) : NULL", | |
249 | "%h ? HT_IDENT_TO_GCC_IDENT (%h) : NULL"))) | |
250 | entries; | |
573aba85 | 251 | unsigned int nslots; |
252 | unsigned int nelements; | |
253 | }; | |
254 | ||
255 | static GTY(()) struct string_pool_data * spd; | |
256 | ||
c39ed964 | 257 | /* Save the stringpool data in SPD. */ |
5b916b55 | 258 | |
573aba85 | 259 | void |
60b8c5b3 | 260 | gt_pch_save_stringpool (void) |
573aba85 | 261 | { |
ba72912a | 262 | spd = ggc_alloc_string_pool_data (); |
573aba85 | 263 | spd->nslots = ident_hash->nslots; |
264 | spd->nelements = ident_hash->nelements; | |
ba72912a | 265 | spd->entries = ggc_alloc_vec_ht_identifier_ptr (spd->nslots); |
8ed01400 | 266 | memcpy (spd->entries, ident_hash->entries, |
267 | spd->nslots * sizeof (spd->entries[0])); | |
78e9fc50 | 268 | } |
269 | ||
5b916b55 | 270 | /* Return the stringpool to its state before gt_pch_save_stringpool |
271 | was called. */ | |
272 | ||
78e9fc50 | 273 | void |
60b8c5b3 | 274 | gt_pch_fixup_stringpool (void) |
78e9fc50 | 275 | { |
573aba85 | 276 | } |
277 | ||
5b916b55 | 278 | /* A PCH file has been restored, which loaded SPD; fill the real hash table |
8ed01400 | 279 | from SPD. */ |
5b916b55 | 280 | |
573aba85 | 281 | void |
60b8c5b3 | 282 | gt_pch_restore_stringpool (void) |
573aba85 | 283 | { |
8ed01400 | 284 | ht_load (ident_hash, spd->entries, spd->nslots, spd->nelements, false); |
573aba85 | 285 | spd = NULL; |
286 | } | |
287 | ||
288 | #include "gt-stringpool.h" |