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14bfc3f5 ILT |
1 | // stringpool.cc -- a string pool for gold |
2 | ||
3 | #include "gold.h" | |
4 | ||
14bfc3f5 | 5 | #include <cstring> |
61ba1cf9 ILT |
6 | #include <algorithm> |
7 | #include <vector> | |
14bfc3f5 | 8 | |
61ba1cf9 | 9 | #include "output.h" |
14bfc3f5 ILT |
10 | #include "stringpool.h" |
11 | ||
12 | namespace gold | |
13 | { | |
14 | ||
b8e6aad9 ILT |
15 | template<typename Stringpool_char> |
16 | Stringpool_template<Stringpool_char>::Stringpool_template(bool zero_null) | |
17 | : string_set_(), strings_(), strtab_size_(0), next_index_(1), | |
18 | zero_null_(zero_null) | |
14bfc3f5 ILT |
19 | { |
20 | } | |
21 | ||
b8e6aad9 ILT |
22 | template<typename Stringpool_char> |
23 | Stringpool_template<Stringpool_char>::~Stringpool_template() | |
14bfc3f5 | 24 | { |
b8e6aad9 | 25 | for (typename std::list<Stringdata*>::iterator p = this->strings_.begin(); |
14bfc3f5 ILT |
26 | p != this->strings_.end(); |
27 | ++p) | |
28 | delete[] reinterpret_cast<char*>(*p); | |
29 | } | |
30 | ||
b8e6aad9 ILT |
31 | // Return the length of a string of arbitrary character type. |
32 | ||
33 | template<typename Stringpool_char> | |
34 | size_t | |
35 | Stringpool_template<Stringpool_char>::string_length(const Stringpool_char* p) | |
36 | { | |
37 | size_t len = 0; | |
38 | for (; *p != 0; ++p) | |
39 | ++len; | |
40 | return len; | |
41 | } | |
42 | ||
43 | // Specialize string_length for char. Maybe we could just use | |
44 | // std::char_traits<>::length? | |
45 | ||
46 | template<> | |
47 | inline size_t | |
48 | Stringpool_template<char>::string_length(const char* p) | |
49 | { | |
50 | return strlen(p); | |
51 | } | |
52 | ||
53 | // Equality comparison function. | |
54 | ||
55 | template<typename Stringpool_char> | |
56 | bool | |
57 | Stringpool_template<Stringpool_char>::Stringpool_eq::operator()( | |
58 | const Stringpool_char* s1, | |
59 | const Stringpool_char* s2) const | |
60 | { | |
61 | while (*s1 != 0) | |
62 | if (*s1++ != *s2++) | |
63 | return false; | |
64 | return *s2 == 0; | |
65 | } | |
66 | ||
67 | // Specialize equality comparison for char. | |
68 | ||
69 | template<> | |
70 | bool | |
71 | Stringpool_template<char>::Stringpool_eq::operator()(const char* s1, | |
72 | const char* s2) const | |
73 | { | |
74 | return strcmp(s1, s2) == 0; | |
75 | } | |
76 | ||
14bfc3f5 ILT |
77 | // Hash function. |
78 | ||
b8e6aad9 | 79 | template<typename Stringpool_char> |
14bfc3f5 | 80 | size_t |
b8e6aad9 ILT |
81 | Stringpool_template<Stringpool_char>::Stringpool_hash::operator()( |
82 | const Stringpool_char* s) const | |
14bfc3f5 ILT |
83 | { |
84 | // Fowler/Noll/Vo (FNV) hash (type FNV-1a). | |
85 | if (sizeof(size_t) == 8) | |
86 | { | |
b3168e9d | 87 | size_t result = static_cast<size_t>(14695981039346656037ULL); |
b8e6aad9 | 88 | while (*s != 0) |
14bfc3f5 | 89 | { |
b8e6aad9 ILT |
90 | const char* p = reinterpret_cast<const char*>(s); |
91 | for (size_t i = 0; i < sizeof(Stringpool_char); ++i) | |
92 | { | |
93 | result &= (size_t) *p++; | |
94 | result *= 1099511628211ULL; | |
95 | } | |
96 | ++s; | |
14bfc3f5 ILT |
97 | } |
98 | return result; | |
99 | } | |
100 | else | |
101 | { | |
102 | size_t result = 2166136261UL; | |
b8e6aad9 | 103 | while (*s != 0) |
14bfc3f5 | 104 | { |
b8e6aad9 ILT |
105 | const char* p = reinterpret_cast<const char*>(s); |
106 | for (size_t i = 0; i < sizeof(Stringpool_char); ++i) | |
107 | { | |
108 | result ^= (size_t) *p++; | |
109 | result *= 16777619UL; | |
110 | } | |
111 | ++s; | |
14bfc3f5 ILT |
112 | } |
113 | return result; | |
114 | } | |
115 | } | |
116 | ||
117 | // Add a string to the list of canonical strings. Return a pointer to | |
f0641a0b | 118 | // the canonical string. If PKEY is not NULL, set *PKEY to the key. |
14bfc3f5 | 119 | |
b8e6aad9 ILT |
120 | template<typename Stringpool_char> |
121 | const Stringpool_char* | |
122 | Stringpool_template<Stringpool_char>::add_string(const Stringpool_char* s, | |
123 | Key* pkey) | |
14bfc3f5 | 124 | { |
a3ad94ed ILT |
125 | // We are in trouble if we've already computed the string offsets. |
126 | gold_assert(this->strtab_size_ == 0); | |
127 | ||
f0641a0b | 128 | // The size we allocate for a new Stringdata. |
14bfc3f5 | 129 | const size_t buffer_size = 1000; |
f0641a0b ILT |
130 | // The amount we multiply the Stringdata index when calculating the |
131 | // key. | |
132 | const size_t key_mult = 1024; | |
a3ad94ed | 133 | gold_assert(key_mult >= buffer_size); |
f0641a0b | 134 | |
b8e6aad9 | 135 | size_t len = (string_length(s) + 1) * sizeof(Stringpool_char); |
14bfc3f5 ILT |
136 | |
137 | size_t alc; | |
138 | bool front = true; | |
b8e6aad9 | 139 | if (len > buffer_size) |
14bfc3f5 | 140 | { |
61ba1cf9 | 141 | alc = sizeof(Stringdata) + len; |
14bfc3f5 ILT |
142 | front = false; |
143 | } | |
144 | else if (this->strings_.empty()) | |
61ba1cf9 | 145 | alc = sizeof(Stringdata) + buffer_size; |
14bfc3f5 ILT |
146 | else |
147 | { | |
61ba1cf9 | 148 | Stringdata *psd = this->strings_.front(); |
b8e6aad9 | 149 | if (len > psd->alc - psd->len) |
61ba1cf9 | 150 | alc = sizeof(Stringdata) + buffer_size; |
14bfc3f5 ILT |
151 | else |
152 | { | |
153 | char* ret = psd->data + psd->len; | |
b8e6aad9 | 154 | memcpy(ret, s, len); |
f0641a0b ILT |
155 | |
156 | if (pkey != NULL) | |
157 | *pkey = psd->index * key_mult + psd->len; | |
158 | ||
b8e6aad9 | 159 | psd->len += len; |
f0641a0b | 160 | |
b8e6aad9 | 161 | return reinterpret_cast<const Stringpool_char*>(ret); |
14bfc3f5 ILT |
162 | } |
163 | } | |
164 | ||
61ba1cf9 ILT |
165 | Stringdata *psd = reinterpret_cast<Stringdata*>(new char[alc]); |
166 | psd->alc = alc - sizeof(Stringdata); | |
b8e6aad9 ILT |
167 | memcpy(psd->data, s, len); |
168 | psd->len = len; | |
f0641a0b ILT |
169 | psd->index = this->next_index_; |
170 | ++this->next_index_; | |
171 | ||
172 | if (pkey != NULL) | |
173 | *pkey = psd->index * key_mult; | |
174 | ||
14bfc3f5 ILT |
175 | if (front) |
176 | this->strings_.push_front(psd); | |
177 | else | |
178 | this->strings_.push_back(psd); | |
f0641a0b | 179 | |
b8e6aad9 | 180 | return reinterpret_cast<const Stringpool_char*>(psd->data); |
14bfc3f5 ILT |
181 | } |
182 | ||
183 | // Add a string to a string pool. | |
184 | ||
b8e6aad9 ILT |
185 | template<typename Stringpool_char> |
186 | const Stringpool_char* | |
187 | Stringpool_template<Stringpool_char>::add(const Stringpool_char* s, Key* pkey) | |
14bfc3f5 ILT |
188 | { |
189 | // FIXME: This will look up the entry twice in the hash table. The | |
190 | // problem is that we can't insert S before we canonicalize it. I | |
a2fb1b05 | 191 | // don't think there is a way to handle this correctly with |
61ba1cf9 | 192 | // unordered_map, so this should be replaced with custom code to do |
14bfc3f5 ILT |
193 | // what we need, which is to return the empty slot. |
194 | ||
b8e6aad9 | 195 | typename String_set_type::const_iterator p = this->string_set_.find(s); |
14bfc3f5 | 196 | if (p != this->string_set_.end()) |
f0641a0b ILT |
197 | { |
198 | if (pkey != NULL) | |
199 | *pkey = p->second.first; | |
200 | return p->first; | |
201 | } | |
14bfc3f5 | 202 | |
f0641a0b | 203 | Key k; |
b8e6aad9 | 204 | const Stringpool_char* ret = this->add_string(s, &k); |
f0641a0b ILT |
205 | |
206 | const off_t ozero = 0; | |
b8e6aad9 ILT |
207 | std::pair<const Stringpool_char*, Val> element(ret, |
208 | std::make_pair(k, ozero)); | |
209 | std::pair<typename String_set_type::iterator, bool> ins = | |
f0641a0b | 210 | this->string_set_.insert(element); |
a3ad94ed | 211 | gold_assert(ins.second); |
f0641a0b ILT |
212 | |
213 | if (pkey != NULL) | |
214 | *pkey = k; | |
215 | ||
14bfc3f5 ILT |
216 | return ret; |
217 | } | |
218 | ||
219 | // Add a prefix of a string to a string pool. | |
220 | ||
b8e6aad9 ILT |
221 | template<typename Stringpool_char> |
222 | const Stringpool_char* | |
223 | Stringpool_template<Stringpool_char>::add(const Stringpool_char* s, size_t len, | |
224 | Key* pkey) | |
14bfc3f5 ILT |
225 | { |
226 | // FIXME: This implementation should be rewritten when we rewrite | |
227 | // the hash table to avoid copying. | |
b8e6aad9 | 228 | std::basic_string<Stringpool_char> st(s, len); |
f0641a0b | 229 | return this->add(st, pkey); |
14bfc3f5 ILT |
230 | } |
231 | ||
b8e6aad9 ILT |
232 | template<typename Stringpool_char> |
233 | const Stringpool_char* | |
234 | Stringpool_template<Stringpool_char>::find(const Stringpool_char* s, | |
235 | Key* pkey) const | |
61ba1cf9 | 236 | { |
b8e6aad9 | 237 | typename String_set_type::const_iterator p = this->string_set_.find(s); |
61ba1cf9 ILT |
238 | if (p == this->string_set_.end()) |
239 | return NULL; | |
f0641a0b ILT |
240 | |
241 | if (pkey != NULL) | |
242 | *pkey = p->second.first; | |
243 | ||
61ba1cf9 ILT |
244 | return p->first; |
245 | } | |
246 | ||
247 | // Comparison routine used when sorting into an ELF strtab. We want | |
248 | // to sort this so that when one string is a suffix of another, we | |
249 | // always see the shorter string immediately after the longer string. | |
250 | // For example, we want to see these strings in this order: | |
251 | // abcd | |
252 | // cd | |
253 | // d | |
254 | // When strings are not suffixes, we don't care what order they are | |
255 | // in, but we need to ensure that suffixes wind up next to each other. | |
256 | // So we do a reversed lexicographic sort on the reversed string. | |
257 | ||
b8e6aad9 | 258 | template<typename Stringpool_char> |
61ba1cf9 | 259 | bool |
b8e6aad9 ILT |
260 | Stringpool_template<Stringpool_char>::Stringpool_sort_comparison::operator()( |
261 | typename String_set_type::iterator it1, | |
262 | typename String_set_type::iterator it2) const | |
61ba1cf9 | 263 | { |
b8e6aad9 ILT |
264 | const Stringpool_char* s1 = it1->first; |
265 | const Stringpool_char* s2 = it2->first; | |
266 | size_t len1 = string_length(s1); | |
267 | size_t len2 = string_length(s2); | |
268 | size_t minlen = len1 < len2 ? len1 : len2; | |
269 | const Stringpool_char* p1 = s1 + len1 - 1; | |
270 | const Stringpool_char* p2 = s2 + len2 - 1; | |
271 | for (size_t i = minlen; i > 0; --i, --p1, --p2) | |
61ba1cf9 ILT |
272 | { |
273 | if (*p1 != *p2) | |
274 | return *p1 > *p2; | |
275 | } | |
276 | return len1 > len2; | |
277 | } | |
278 | ||
279 | // Return whether s1 is a suffix of s2. | |
280 | ||
b8e6aad9 | 281 | template<typename Stringpool_char> |
61ba1cf9 | 282 | bool |
b8e6aad9 ILT |
283 | Stringpool_template<Stringpool_char>::is_suffix(const Stringpool_char* s1, |
284 | const Stringpool_char* s2) | |
61ba1cf9 | 285 | { |
b8e6aad9 ILT |
286 | size_t len1 = string_length(s1); |
287 | size_t len2 = string_length(s2); | |
61ba1cf9 ILT |
288 | if (len1 > len2) |
289 | return false; | |
b8e6aad9 | 290 | return memcmp(s1, s2 + len2 - len1, len1 * sizeof(Stringpool_char)) == 0; |
61ba1cf9 ILT |
291 | } |
292 | ||
293 | // Turn the stringpool into an ELF strtab: determine the offsets of | |
294 | // each string in the table. | |
295 | ||
b8e6aad9 | 296 | template<typename Stringpool_char> |
61ba1cf9 | 297 | void |
b8e6aad9 | 298 | Stringpool_template<Stringpool_char>::set_string_offsets() |
61ba1cf9 | 299 | { |
a3ad94ed ILT |
300 | if (this->strtab_size_ != 0) |
301 | { | |
302 | // We've already computed the offsets. | |
303 | return; | |
304 | } | |
305 | ||
61ba1cf9 ILT |
306 | size_t count = this->string_set_.size(); |
307 | ||
b8e6aad9 | 308 | std::vector<typename String_set_type::iterator> v; |
61ba1cf9 ILT |
309 | v.reserve(count); |
310 | ||
b8e6aad9 | 311 | for (typename String_set_type::iterator p = this->string_set_.begin(); |
61ba1cf9 ILT |
312 | p != this->string_set_.end(); |
313 | ++p) | |
314 | v.push_back(p); | |
315 | ||
316 | std::sort(v.begin(), v.end(), Stringpool_sort_comparison()); | |
317 | ||
b8e6aad9 ILT |
318 | const size_t charsize = sizeof(Stringpool_char); |
319 | ||
320 | // Offset 0 may be reserved for the empty string. | |
321 | off_t offset = this->zero_null_ ? charsize : 0; | |
61ba1cf9 ILT |
322 | for (size_t i = 0; i < count; ++i) |
323 | { | |
b8e6aad9 | 324 | if (this->zero_null_ && v[i]->first[0] == 0) |
f0641a0b | 325 | v[i]->second.second = 0; |
b8e6aad9 | 326 | else if (i > 0 && is_suffix(v[i]->first, v[i - 1]->first)) |
f0641a0b | 327 | v[i]->second.second = (v[i - 1]->second.second |
b8e6aad9 ILT |
328 | + ((string_length(v[i - 1]->first) |
329 | - string_length(v[i]->first)) | |
330 | * charsize)); | |
61ba1cf9 ILT |
331 | else |
332 | { | |
f0641a0b | 333 | v[i]->second.second = offset; |
b8e6aad9 | 334 | offset += (string_length(v[i]->first) + 1) * charsize; |
61ba1cf9 ILT |
335 | } |
336 | } | |
337 | ||
338 | this->strtab_size_ = offset; | |
339 | } | |
340 | ||
341 | // Get the offset of a string in the ELF strtab. The string must | |
342 | // exist. | |
343 | ||
b8e6aad9 | 344 | template<typename Stringpool_char> |
61ba1cf9 | 345 | off_t |
b8e6aad9 ILT |
346 | Stringpool_template<Stringpool_char>::get_offset(const Stringpool_char* s) |
347 | const | |
61ba1cf9 | 348 | { |
a3ad94ed | 349 | gold_assert(this->strtab_size_ != 0); |
b8e6aad9 | 350 | typename String_set_type::const_iterator p = this->string_set_.find(s); |
61ba1cf9 | 351 | if (p != this->string_set_.end()) |
f0641a0b | 352 | return p->second.second; |
a3ad94ed | 353 | gold_unreachable(); |
61ba1cf9 ILT |
354 | } |
355 | ||
356 | // Write the ELF strtab into the output file at the specified offset. | |
357 | ||
b8e6aad9 | 358 | template<typename Stringpool_char> |
61ba1cf9 | 359 | void |
b8e6aad9 | 360 | Stringpool_template<Stringpool_char>::write(Output_file* of, off_t offset) |
61ba1cf9 | 361 | { |
a3ad94ed | 362 | gold_assert(this->strtab_size_ != 0); |
61ba1cf9 ILT |
363 | unsigned char* viewu = of->get_output_view(offset, this->strtab_size_); |
364 | char* view = reinterpret_cast<char*>(viewu); | |
b8e6aad9 ILT |
365 | if (this->zero_null_) |
366 | view[0] = '\0'; | |
367 | for (typename String_set_type::const_iterator p = this->string_set_.begin(); | |
61ba1cf9 ILT |
368 | p != this->string_set_.end(); |
369 | ++p) | |
b8e6aad9 ILT |
370 | memcpy(view + p->second.second, p->first, |
371 | (string_length(p->first) + 1) * sizeof(Stringpool_char)); | |
61ba1cf9 ILT |
372 | of->write_output_view(offset, this->strtab_size_, viewu); |
373 | } | |
374 | ||
b8e6aad9 ILT |
375 | // Instantiate the templates we need. |
376 | ||
377 | template | |
378 | class Stringpool_template<char>; | |
379 | ||
380 | template | |
381 | class Stringpool_template<uint16_t>; | |
382 | ||
383 | template | |
384 | class Stringpool_template<uint32_t>; | |
385 | ||
14bfc3f5 | 386 | } // End namespace gold. |