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14bfc3f5 ILT |
1 | // resolve.cc -- symbol resolution for gold |
2 | ||
6cb15b7f ILT |
3 | // Copyright 2006, 2007 Free Software Foundation, Inc. |
4 | // Written by Ian Lance Taylor <iant@google.com>. | |
5 | ||
6 | // This file is part of gold. | |
7 | ||
8 | // This program is free software; you can redistribute it and/or modify | |
9 | // it under the terms of the GNU General Public License as published by | |
10 | // the Free Software Foundation; either version 3 of the License, or | |
11 | // (at your option) any later version. | |
12 | ||
13 | // This program is distributed in the hope that it will be useful, | |
14 | // but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | // GNU General Public License for more details. | |
17 | ||
18 | // You should have received a copy of the GNU General Public License | |
19 | // along with this program; if not, write to the Free Software | |
20 | // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, | |
21 | // MA 02110-1301, USA. | |
22 | ||
14bfc3f5 ILT |
23 | #include "gold.h" |
24 | ||
25 | #include "elfcpp.h" | |
26 | #include "target.h" | |
27 | #include "object.h" | |
28 | #include "symtab.h" | |
29 | ||
30 | namespace gold | |
31 | { | |
32 | ||
1564db8d ILT |
33 | // Symbol methods used in this file. |
34 | ||
35 | // Override the fields in Symbol. | |
36 | ||
37 | template<int size, bool big_endian> | |
38 | void | |
39 | Symbol::override_base(const elfcpp::Sym<size, big_endian>& sym, | |
14b31740 | 40 | Object* object, const char* version) |
1564db8d | 41 | { |
a3ad94ed | 42 | gold_assert(this->source_ == FROM_OBJECT); |
ead1e424 | 43 | this->u_.from_object.object = object; |
14b31740 ILT |
44 | if (version != NULL && this->version() != version) |
45 | { | |
46 | gold_assert(this->version() == NULL); | |
47 | this->version_ = version; | |
48 | } | |
ead1e424 | 49 | // FIXME: Handle SHN_XINDEX. |
16649710 | 50 | this->u_.from_object.shndx = sym.get_st_shndx(); |
1564db8d ILT |
51 | this->type_ = sym.get_st_type(); |
52 | this->binding_ = sym.get_st_bind(); | |
53 | this->visibility_ = sym.get_st_visibility(); | |
ead1e424 | 54 | this->nonvis_ = sym.get_st_nonvis(); |
0d4f1889 ILT |
55 | if (object->is_dynamic()) |
56 | this->in_dyn_ = true; | |
57 | else | |
58 | this->in_reg_ = true; | |
1564db8d ILT |
59 | } |
60 | ||
61 | // Override the fields in Sized_symbol. | |
62 | ||
63 | template<int size> | |
64 | template<bool big_endian> | |
65 | void | |
66 | Sized_symbol<size>::override(const elfcpp::Sym<size, big_endian>& sym, | |
14b31740 | 67 | Object* object, const char* version) |
1564db8d | 68 | { |
14b31740 | 69 | this->override_base(sym, object, version); |
1564db8d | 70 | this->value_ = sym.get_st_value(); |
ead1e424 | 71 | this->symsize_ = sym.get_st_size(); |
1564db8d ILT |
72 | } |
73 | ||
aeddab66 ILT |
74 | // Override TOSYM with symbol FROMSYM, defined in OBJECT, with version |
75 | // VERSION. This handles all aliases of TOSYM. | |
76 | ||
77 | template<int size, bool big_endian> | |
78 | void | |
79 | Symbol_table::override(Sized_symbol<size>* tosym, | |
80 | const elfcpp::Sym<size, big_endian>& fromsym, | |
81 | Object* object, const char* version) | |
82 | { | |
83 | tosym->override(fromsym, object, version); | |
84 | if (tosym->has_alias()) | |
85 | { | |
86 | Symbol* sym = this->weak_aliases_[tosym]; | |
87 | gold_assert(sym != NULL); | |
88 | Sized_symbol<size>* ssym; | |
89 | ssym = this->get_sized_symbol SELECT_SIZE_NAME(size) (sym | |
90 | SELECT_SIZE(size)); | |
91 | do | |
92 | { | |
93 | ssym->override(fromsym, object, version); | |
94 | sym = this->weak_aliases_[ssym]; | |
95 | gold_assert(sym != NULL); | |
96 | ssym = this->get_sized_symbol SELECT_SIZE_NAME(size) ( | |
97 | sym SELECT_SIZE(size)); | |
98 | } | |
99 | while (ssym != tosym); | |
100 | } | |
101 | } | |
102 | ||
86f2e683 ILT |
103 | // The resolve functions build a little code for each symbol. |
104 | // Bit 0: 0 for global, 1 for weak. | |
105 | // Bit 1: 0 for regular object, 1 for shared object | |
106 | // Bits 2-3: 0 for normal, 1 for undefined, 2 for common | |
107 | // This gives us values from 0 to 11. | |
108 | ||
109 | static const int global_or_weak_shift = 0; | |
110 | static const unsigned int global_flag = 0 << global_or_weak_shift; | |
111 | static const unsigned int weak_flag = 1 << global_or_weak_shift; | |
112 | ||
113 | static const int regular_or_dynamic_shift = 1; | |
114 | static const unsigned int regular_flag = 0 << regular_or_dynamic_shift; | |
115 | static const unsigned int dynamic_flag = 1 << regular_or_dynamic_shift; | |
116 | ||
117 | static const int def_undef_or_common_shift = 2; | |
118 | static const unsigned int def_flag = 0 << def_undef_or_common_shift; | |
119 | static const unsigned int undef_flag = 1 << def_undef_or_common_shift; | |
120 | static const unsigned int common_flag = 2 << def_undef_or_common_shift; | |
121 | ||
14bfc3f5 ILT |
122 | // Resolve a symbol. This is called the second and subsequent times |
123 | // we see a symbol. TO is the pre-existing symbol. SYM is the new | |
14b31740 | 124 | // symbol, seen in OBJECT. VERSION of the version of SYM. |
14bfc3f5 ILT |
125 | |
126 | template<int size, bool big_endian> | |
127 | void | |
1564db8d | 128 | Symbol_table::resolve(Sized_symbol<size>* to, |
14bfc3f5 | 129 | const elfcpp::Sym<size, big_endian>& sym, |
14b31740 | 130 | Object* object, const char* version) |
14bfc3f5 ILT |
131 | { |
132 | if (object->target()->has_resolve()) | |
133 | { | |
274e99f9 | 134 | Sized_target<size, big_endian>* sized_target; |
593f47df ILT |
135 | sized_target = object->sized_target |
136 | SELECT_SIZE_ENDIAN_NAME(size, big_endian) ( | |
137 | SELECT_SIZE_ENDIAN_ONLY(size, big_endian)); | |
14b31740 | 138 | sized_target->resolve(to, sym, object, version); |
14bfc3f5 ILT |
139 | return; |
140 | } | |
141 | ||
86f2e683 ILT |
142 | if (!object->is_dynamic()) |
143 | { | |
144 | // Record that we've seen this symbol in a regular object. | |
145 | to->set_in_reg(); | |
146 | } | |
147 | else | |
148 | { | |
149 | // Record that we've seen this symbol in a dynamic object. | |
150 | to->set_in_dyn(); | |
151 | } | |
14bfc3f5 | 152 | |
86f2e683 ILT |
153 | unsigned int frombits; |
154 | switch (sym.get_st_bind()) | |
14bfc3f5 ILT |
155 | { |
156 | case elfcpp::STB_GLOBAL: | |
86f2e683 | 157 | frombits = global_flag; |
14bfc3f5 ILT |
158 | break; |
159 | ||
160 | case elfcpp::STB_WEAK: | |
86f2e683 | 161 | frombits = weak_flag; |
14bfc3f5 ILT |
162 | break; |
163 | ||
164 | case elfcpp::STB_LOCAL: | |
75f2446e ILT |
165 | gold_error(_("%s: invalid STB_LOCAL symbol %s in external symbols"), |
166 | object->name().c_str(), to->name()); | |
167 | frombits = global_flag; | |
168 | break; | |
14bfc3f5 ILT |
169 | |
170 | default: | |
75f2446e ILT |
171 | gold_error(_("%s: unsupported symbol binding %d for symbol %s"), |
172 | object->name().c_str(), | |
173 | static_cast<int>(sym.get_st_bind()), to->name()); | |
174 | frombits = global_flag; | |
175 | break; | |
14bfc3f5 ILT |
176 | } |
177 | ||
86f2e683 ILT |
178 | if (!object->is_dynamic()) |
179 | frombits |= regular_flag; | |
180 | else | |
181 | frombits |= dynamic_flag; | |
14bfc3f5 | 182 | |
86f2e683 | 183 | switch (sym.get_st_shndx()) |
14bfc3f5 ILT |
184 | { |
185 | case elfcpp::SHN_UNDEF: | |
86f2e683 | 186 | frombits |= undef_flag; |
14bfc3f5 ILT |
187 | break; |
188 | ||
189 | case elfcpp::SHN_COMMON: | |
86f2e683 | 190 | frombits |= common_flag; |
14bfc3f5 ILT |
191 | break; |
192 | ||
193 | default: | |
86f2e683 ILT |
194 | if (sym.get_st_type() == elfcpp::STT_COMMON) |
195 | frombits |= common_flag; | |
196 | else | |
197 | frombits |= def_flag; | |
14bfc3f5 ILT |
198 | break; |
199 | } | |
200 | ||
86f2e683 | 201 | bool adjust_common_sizes; |
d20222a1 ILT |
202 | if (Symbol_table::should_override(to, frombits, object, |
203 | &adjust_common_sizes)) | |
86f2e683 ILT |
204 | { |
205 | typename Sized_symbol<size>::Size_type tosize = to->symsize(); | |
206 | ||
aeddab66 | 207 | this->override(to, sym, object, version); |
86f2e683 ILT |
208 | |
209 | if (adjust_common_sizes && tosize > to->symsize()) | |
210 | to->set_symsize(tosize); | |
211 | } | |
212 | else | |
213 | { | |
214 | if (adjust_common_sizes && sym.get_st_size() > to->symsize()) | |
215 | to->set_symsize(sym.get_st_size()); | |
216 | } | |
217 | } | |
218 | ||
219 | // Handle the core of symbol resolution. This is called with the | |
220 | // existing symbol, TO, and a bitflag describing the new symbol. This | |
221 | // returns true if we should override the existing symbol with the new | |
222 | // one, and returns false otherwise. It sets *ADJUST_COMMON_SIZES to | |
223 | // true if we should set the symbol size to the maximum of the TO and | |
224 | // FROM sizes. It handles error conditions. | |
225 | ||
226 | bool | |
227 | Symbol_table::should_override(const Symbol* to, unsigned int frombits, | |
d20222a1 | 228 | Object* object, bool* adjust_common_sizes) |
86f2e683 ILT |
229 | { |
230 | *adjust_common_sizes = false; | |
231 | ||
232 | unsigned int tobits; | |
233 | switch (to->binding()) | |
14bfc3f5 ILT |
234 | { |
235 | case elfcpp::STB_GLOBAL: | |
86f2e683 | 236 | tobits = global_flag; |
14bfc3f5 ILT |
237 | break; |
238 | ||
239 | case elfcpp::STB_WEAK: | |
86f2e683 | 240 | tobits = weak_flag; |
14bfc3f5 ILT |
241 | break; |
242 | ||
243 | case elfcpp::STB_LOCAL: | |
86f2e683 ILT |
244 | // We should only see externally visible symbols in the symbol |
245 | // table. | |
246 | gold_unreachable(); | |
14bfc3f5 ILT |
247 | |
248 | default: | |
86f2e683 ILT |
249 | // Any target which wants to handle STB_LOOS, etc., needs to |
250 | // define a resolve method. | |
251 | gold_unreachable(); | |
14bfc3f5 ILT |
252 | } |
253 | ||
86f2e683 ILT |
254 | if (to->source() == Symbol::FROM_OBJECT |
255 | && to->object()->is_dynamic()) | |
256 | tobits |= dynamic_flag; | |
008db82e | 257 | else |
86f2e683 | 258 | tobits |= regular_flag; |
1564db8d | 259 | |
86f2e683 | 260 | switch (to->shndx()) |
14bfc3f5 ILT |
261 | { |
262 | case elfcpp::SHN_UNDEF: | |
86f2e683 | 263 | tobits |= undef_flag; |
14bfc3f5 ILT |
264 | break; |
265 | ||
266 | case elfcpp::SHN_COMMON: | |
86f2e683 | 267 | tobits |= common_flag; |
14bfc3f5 ILT |
268 | break; |
269 | ||
270 | default: | |
86f2e683 ILT |
271 | if (to->type() == elfcpp::STT_COMMON) |
272 | tobits |= common_flag; | |
273 | else | |
274 | tobits |= def_flag; | |
14bfc3f5 ILT |
275 | break; |
276 | } | |
277 | ||
1564db8d ILT |
278 | // FIXME: Warn if either but not both of TO and SYM are STT_TLS. |
279 | ||
14bfc3f5 ILT |
280 | // We use a giant switch table for symbol resolution. This code is |
281 | // unwieldy, but: 1) it is efficient; 2) we definitely handle all | |
282 | // cases; 3) it is easy to change the handling of a particular case. | |
283 | // The alternative would be a series of conditionals, but it is easy | |
284 | // to get the ordering wrong. This could also be done as a table, | |
285 | // but that is no easier to understand than this large switch | |
286 | // statement. | |
287 | ||
86f2e683 ILT |
288 | // These are the values generated by the bit codes. |
289 | enum | |
290 | { | |
291 | DEF = global_flag | regular_flag | def_flag, | |
292 | WEAK_DEF = weak_flag | regular_flag | def_flag, | |
293 | DYN_DEF = global_flag | dynamic_flag | def_flag, | |
294 | DYN_WEAK_DEF = weak_flag | dynamic_flag | def_flag, | |
295 | UNDEF = global_flag | regular_flag | undef_flag, | |
296 | WEAK_UNDEF = weak_flag | regular_flag | undef_flag, | |
297 | DYN_UNDEF = global_flag | dynamic_flag | undef_flag, | |
298 | DYN_WEAK_UNDEF = weak_flag | dynamic_flag | undef_flag, | |
299 | COMMON = global_flag | regular_flag | common_flag, | |
300 | WEAK_COMMON = weak_flag | regular_flag | common_flag, | |
301 | DYN_COMMON = global_flag | dynamic_flag | common_flag, | |
302 | DYN_WEAK_COMMON = weak_flag | dynamic_flag | common_flag | |
303 | }; | |
304 | ||
14bfc3f5 ILT |
305 | switch (tobits * 16 + frombits) |
306 | { | |
307 | case DEF * 16 + DEF: | |
12e14209 | 308 | // Two definitions of the same symbol. |
d20222a1 ILT |
309 | // FIXME: Do a better job of reporting locations. |
310 | gold_error(_("%s: multiple definition of %s"), | |
311 | object != NULL ? object->name().c_str() : _("command line"), | |
312 | to->name()); | |
313 | gold_error(_("%s: previous definition here"), | |
314 | (to->source() == Symbol::FROM_OBJECT | |
315 | ? to->object()->name().c_str() | |
316 | : _("command line"))); | |
86f2e683 | 317 | return false; |
14bfc3f5 ILT |
318 | |
319 | case WEAK_DEF * 16 + DEF: | |
1564db8d ILT |
320 | // We've seen a weak definition, and now we see a strong |
321 | // definition. In the original SVR4 linker, this was treated as | |
322 | // a multiple definition error. In the Solaris linker and the | |
323 | // GNU linker, a weak definition followed by a regular | |
324 | // definition causes the weak definition to be overridden. We | |
325 | // are currently compatible with the GNU linker. In the future | |
326 | // we should add a target specific option to change this. | |
327 | // FIXME. | |
86f2e683 | 328 | return true; |
14bfc3f5 ILT |
329 | |
330 | case DYN_DEF * 16 + DEF: | |
331 | case DYN_WEAK_DEF * 16 + DEF: | |
1564db8d ILT |
332 | // We've seen a definition in a dynamic object, and now we see a |
333 | // definition in a regular object. The definition in the | |
334 | // regular object overrides the definition in the dynamic | |
335 | // object. | |
86f2e683 | 336 | return true; |
1564db8d | 337 | |
14bfc3f5 ILT |
338 | case UNDEF * 16 + DEF: |
339 | case WEAK_UNDEF * 16 + DEF: | |
340 | case DYN_UNDEF * 16 + DEF: | |
341 | case DYN_WEAK_UNDEF * 16 + DEF: | |
1564db8d ILT |
342 | // We've seen an undefined reference, and now we see a |
343 | // definition. We use the definition. | |
86f2e683 | 344 | return true; |
1564db8d | 345 | |
14bfc3f5 ILT |
346 | case COMMON * 16 + DEF: |
347 | case WEAK_COMMON * 16 + DEF: | |
348 | case DYN_COMMON * 16 + DEF: | |
349 | case DYN_WEAK_COMMON * 16 + DEF: | |
1564db8d | 350 | // We've seen a common symbol and now we see a definition. The |
14b31740 | 351 | // definition overrides. FIXME: We should optionally issue, version a |
1564db8d | 352 | // warning. |
86f2e683 | 353 | return true; |
14bfc3f5 ILT |
354 | |
355 | case DEF * 16 + WEAK_DEF: | |
356 | case WEAK_DEF * 16 + WEAK_DEF: | |
1564db8d ILT |
357 | // We've seen a definition and now we see a weak definition. We |
358 | // ignore the new weak definition. | |
86f2e683 | 359 | return false; |
1564db8d | 360 | |
14bfc3f5 ILT |
361 | case DYN_DEF * 16 + WEAK_DEF: |
362 | case DYN_WEAK_DEF * 16 + WEAK_DEF: | |
1564db8d ILT |
363 | // We've seen a dynamic definition and now we see a regular weak |
364 | // definition. The regular weak definition overrides. | |
86f2e683 | 365 | return true; |
1564db8d | 366 | |
14bfc3f5 ILT |
367 | case UNDEF * 16 + WEAK_DEF: |
368 | case WEAK_UNDEF * 16 + WEAK_DEF: | |
369 | case DYN_UNDEF * 16 + WEAK_DEF: | |
370 | case DYN_WEAK_UNDEF * 16 + WEAK_DEF: | |
1564db8d | 371 | // A weak definition of a currently undefined symbol. |
86f2e683 | 372 | return true; |
1564db8d | 373 | |
14bfc3f5 ILT |
374 | case COMMON * 16 + WEAK_DEF: |
375 | case WEAK_COMMON * 16 + WEAK_DEF: | |
1564db8d | 376 | // A weak definition does not override a common definition. |
86f2e683 | 377 | return false; |
1564db8d | 378 | |
14bfc3f5 ILT |
379 | case DYN_COMMON * 16 + WEAK_DEF: |
380 | case DYN_WEAK_COMMON * 16 + WEAK_DEF: | |
1564db8d ILT |
381 | // A weak definition does override a definition in a dynamic |
382 | // object. FIXME: We should optionally issue a warning. | |
86f2e683 | 383 | return true; |
14bfc3f5 ILT |
384 | |
385 | case DEF * 16 + DYN_DEF: | |
386 | case WEAK_DEF * 16 + DYN_DEF: | |
387 | case DYN_DEF * 16 + DYN_DEF: | |
388 | case DYN_WEAK_DEF * 16 + DYN_DEF: | |
1564db8d | 389 | // Ignore a dynamic definition if we already have a definition. |
86f2e683 | 390 | return false; |
1564db8d | 391 | |
14bfc3f5 ILT |
392 | case UNDEF * 16 + DYN_DEF: |
393 | case WEAK_UNDEF * 16 + DYN_DEF: | |
394 | case DYN_UNDEF * 16 + DYN_DEF: | |
395 | case DYN_WEAK_UNDEF * 16 + DYN_DEF: | |
1564db8d | 396 | // Use a dynamic definition if we have a reference. |
86f2e683 | 397 | return true; |
1564db8d | 398 | |
14bfc3f5 ILT |
399 | case COMMON * 16 + DYN_DEF: |
400 | case WEAK_COMMON * 16 + DYN_DEF: | |
401 | case DYN_COMMON * 16 + DYN_DEF: | |
402 | case DYN_WEAK_COMMON * 16 + DYN_DEF: | |
1564db8d ILT |
403 | // Ignore a dynamic definition if we already have a common |
404 | // definition. | |
86f2e683 | 405 | return false; |
14bfc3f5 ILT |
406 | |
407 | case DEF * 16 + DYN_WEAK_DEF: | |
408 | case WEAK_DEF * 16 + DYN_WEAK_DEF: | |
409 | case DYN_DEF * 16 + DYN_WEAK_DEF: | |
410 | case DYN_WEAK_DEF * 16 + DYN_WEAK_DEF: | |
1564db8d ILT |
411 | // Ignore a weak dynamic definition if we already have a |
412 | // definition. | |
86f2e683 | 413 | return false; |
1564db8d | 414 | |
14bfc3f5 ILT |
415 | case UNDEF * 16 + DYN_WEAK_DEF: |
416 | case WEAK_UNDEF * 16 + DYN_WEAK_DEF: | |
417 | case DYN_UNDEF * 16 + DYN_WEAK_DEF: | |
418 | case DYN_WEAK_UNDEF * 16 + DYN_WEAK_DEF: | |
1564db8d | 419 | // Use a weak dynamic definition if we have a reference. |
86f2e683 | 420 | return true; |
1564db8d | 421 | |
14bfc3f5 ILT |
422 | case COMMON * 16 + DYN_WEAK_DEF: |
423 | case WEAK_COMMON * 16 + DYN_WEAK_DEF: | |
424 | case DYN_COMMON * 16 + DYN_WEAK_DEF: | |
425 | case DYN_WEAK_COMMON * 16 + DYN_WEAK_DEF: | |
1564db8d ILT |
426 | // Ignore a weak dynamic definition if we already have a common |
427 | // definition. | |
86f2e683 | 428 | return false; |
14bfc3f5 ILT |
429 | |
430 | case DEF * 16 + UNDEF: | |
431 | case WEAK_DEF * 16 + UNDEF: | |
432 | case DYN_DEF * 16 + UNDEF: | |
433 | case DYN_WEAK_DEF * 16 + UNDEF: | |
434 | case UNDEF * 16 + UNDEF: | |
ead1e424 | 435 | // A new undefined reference tells us nothing. |
86f2e683 | 436 | return false; |
ead1e424 | 437 | |
14bfc3f5 ILT |
438 | case WEAK_UNDEF * 16 + UNDEF: |
439 | case DYN_UNDEF * 16 + UNDEF: | |
440 | case DYN_WEAK_UNDEF * 16 + UNDEF: | |
ead1e424 | 441 | // A strong undef overrides a dynamic or weak undef. |
86f2e683 | 442 | return true; |
ead1e424 | 443 | |
14bfc3f5 ILT |
444 | case COMMON * 16 + UNDEF: |
445 | case WEAK_COMMON * 16 + UNDEF: | |
446 | case DYN_COMMON * 16 + UNDEF: | |
447 | case DYN_WEAK_COMMON * 16 + UNDEF: | |
1564db8d | 448 | // A new undefined reference tells us nothing. |
86f2e683 | 449 | return false; |
14bfc3f5 ILT |
450 | |
451 | case DEF * 16 + WEAK_UNDEF: | |
452 | case WEAK_DEF * 16 + WEAK_UNDEF: | |
453 | case DYN_DEF * 16 + WEAK_UNDEF: | |
454 | case DYN_WEAK_DEF * 16 + WEAK_UNDEF: | |
455 | case UNDEF * 16 + WEAK_UNDEF: | |
456 | case WEAK_UNDEF * 16 + WEAK_UNDEF: | |
457 | case DYN_UNDEF * 16 + WEAK_UNDEF: | |
458 | case DYN_WEAK_UNDEF * 16 + WEAK_UNDEF: | |
459 | case COMMON * 16 + WEAK_UNDEF: | |
460 | case WEAK_COMMON * 16 + WEAK_UNDEF: | |
461 | case DYN_COMMON * 16 + WEAK_UNDEF: | |
462 | case DYN_WEAK_COMMON * 16 + WEAK_UNDEF: | |
1564db8d | 463 | // A new weak undefined reference tells us nothing. |
86f2e683 | 464 | return false; |
14bfc3f5 ILT |
465 | |
466 | case DEF * 16 + DYN_UNDEF: | |
467 | case WEAK_DEF * 16 + DYN_UNDEF: | |
468 | case DYN_DEF * 16 + DYN_UNDEF: | |
469 | case DYN_WEAK_DEF * 16 + DYN_UNDEF: | |
470 | case UNDEF * 16 + DYN_UNDEF: | |
471 | case WEAK_UNDEF * 16 + DYN_UNDEF: | |
472 | case DYN_UNDEF * 16 + DYN_UNDEF: | |
473 | case DYN_WEAK_UNDEF * 16 + DYN_UNDEF: | |
474 | case COMMON * 16 + DYN_UNDEF: | |
475 | case WEAK_COMMON * 16 + DYN_UNDEF: | |
476 | case DYN_COMMON * 16 + DYN_UNDEF: | |
477 | case DYN_WEAK_COMMON * 16 + DYN_UNDEF: | |
1564db8d | 478 | // A new dynamic undefined reference tells us nothing. |
86f2e683 | 479 | return false; |
14bfc3f5 ILT |
480 | |
481 | case DEF * 16 + DYN_WEAK_UNDEF: | |
482 | case WEAK_DEF * 16 + DYN_WEAK_UNDEF: | |
483 | case DYN_DEF * 16 + DYN_WEAK_UNDEF: | |
484 | case DYN_WEAK_DEF * 16 + DYN_WEAK_UNDEF: | |
485 | case UNDEF * 16 + DYN_WEAK_UNDEF: | |
486 | case WEAK_UNDEF * 16 + DYN_WEAK_UNDEF: | |
487 | case DYN_UNDEF * 16 + DYN_WEAK_UNDEF: | |
488 | case DYN_WEAK_UNDEF * 16 + DYN_WEAK_UNDEF: | |
489 | case COMMON * 16 + DYN_WEAK_UNDEF: | |
490 | case WEAK_COMMON * 16 + DYN_WEAK_UNDEF: | |
491 | case DYN_COMMON * 16 + DYN_WEAK_UNDEF: | |
492 | case DYN_WEAK_COMMON * 16 + DYN_WEAK_UNDEF: | |
1564db8d | 493 | // A new weak dynamic undefined reference tells us nothing. |
86f2e683 | 494 | return false; |
14bfc3f5 ILT |
495 | |
496 | case DEF * 16 + COMMON: | |
1564db8d | 497 | // A common symbol does not override a definition. |
86f2e683 | 498 | return false; |
1564db8d | 499 | |
14bfc3f5 ILT |
500 | case WEAK_DEF * 16 + COMMON: |
501 | case DYN_DEF * 16 + COMMON: | |
502 | case DYN_WEAK_DEF * 16 + COMMON: | |
1564db8d ILT |
503 | // A common symbol does override a weak definition or a dynamic |
504 | // definition. | |
86f2e683 | 505 | return true; |
1564db8d | 506 | |
14bfc3f5 ILT |
507 | case UNDEF * 16 + COMMON: |
508 | case WEAK_UNDEF * 16 + COMMON: | |
509 | case DYN_UNDEF * 16 + COMMON: | |
510 | case DYN_WEAK_UNDEF * 16 + COMMON: | |
1564db8d | 511 | // A common symbol is a definition for a reference. |
86f2e683 | 512 | return true; |
1564db8d | 513 | |
14bfc3f5 | 514 | case COMMON * 16 + COMMON: |
ead1e424 | 515 | // Set the size to the maximum. |
86f2e683 ILT |
516 | *adjust_common_sizes = true; |
517 | return false; | |
ead1e424 | 518 | |
14bfc3f5 | 519 | case WEAK_COMMON * 16 + COMMON: |
ead1e424 ILT |
520 | // I'm not sure just what a weak common symbol means, but |
521 | // presumably it can be overridden by a regular common symbol. | |
86f2e683 | 522 | return true; |
ead1e424 | 523 | |
14bfc3f5 ILT |
524 | case DYN_COMMON * 16 + COMMON: |
525 | case DYN_WEAK_COMMON * 16 + COMMON: | |
86f2e683 ILT |
526 | // Use the real common symbol, but adjust the size if necessary. |
527 | *adjust_common_sizes = true; | |
528 | return true; | |
14bfc3f5 ILT |
529 | |
530 | case DEF * 16 + WEAK_COMMON: | |
531 | case WEAK_DEF * 16 + WEAK_COMMON: | |
532 | case DYN_DEF * 16 + WEAK_COMMON: | |
533 | case DYN_WEAK_DEF * 16 + WEAK_COMMON: | |
ead1e424 ILT |
534 | // Whatever a weak common symbol is, it won't override a |
535 | // definition. | |
86f2e683 | 536 | return false; |
ead1e424 | 537 | |
14bfc3f5 ILT |
538 | case UNDEF * 16 + WEAK_COMMON: |
539 | case WEAK_UNDEF * 16 + WEAK_COMMON: | |
540 | case DYN_UNDEF * 16 + WEAK_COMMON: | |
541 | case DYN_WEAK_UNDEF * 16 + WEAK_COMMON: | |
ead1e424 | 542 | // A weak common symbol is better than an undefined symbol. |
86f2e683 | 543 | return true; |
ead1e424 | 544 | |
14bfc3f5 ILT |
545 | case COMMON * 16 + WEAK_COMMON: |
546 | case WEAK_COMMON * 16 + WEAK_COMMON: | |
547 | case DYN_COMMON * 16 + WEAK_COMMON: | |
548 | case DYN_WEAK_COMMON * 16 + WEAK_COMMON: | |
ead1e424 ILT |
549 | // Ignore a weak common symbol in the presence of a real common |
550 | // symbol. | |
86f2e683 | 551 | return false; |
14bfc3f5 ILT |
552 | |
553 | case DEF * 16 + DYN_COMMON: | |
554 | case WEAK_DEF * 16 + DYN_COMMON: | |
555 | case DYN_DEF * 16 + DYN_COMMON: | |
556 | case DYN_WEAK_DEF * 16 + DYN_COMMON: | |
ead1e424 ILT |
557 | // Ignore a dynamic common symbol in the presence of a |
558 | // definition. | |
86f2e683 | 559 | return false; |
ead1e424 | 560 | |
14bfc3f5 ILT |
561 | case UNDEF * 16 + DYN_COMMON: |
562 | case WEAK_UNDEF * 16 + DYN_COMMON: | |
563 | case DYN_UNDEF * 16 + DYN_COMMON: | |
564 | case DYN_WEAK_UNDEF * 16 + DYN_COMMON: | |
ead1e424 | 565 | // A dynamic common symbol is a definition of sorts. |
86f2e683 | 566 | return true; |
ead1e424 | 567 | |
14bfc3f5 ILT |
568 | case COMMON * 16 + DYN_COMMON: |
569 | case WEAK_COMMON * 16 + DYN_COMMON: | |
570 | case DYN_COMMON * 16 + DYN_COMMON: | |
571 | case DYN_WEAK_COMMON * 16 + DYN_COMMON: | |
ead1e424 | 572 | // Set the size to the maximum. |
86f2e683 ILT |
573 | *adjust_common_sizes = true; |
574 | return false; | |
14bfc3f5 ILT |
575 | |
576 | case DEF * 16 + DYN_WEAK_COMMON: | |
577 | case WEAK_DEF * 16 + DYN_WEAK_COMMON: | |
578 | case DYN_DEF * 16 + DYN_WEAK_COMMON: | |
579 | case DYN_WEAK_DEF * 16 + DYN_WEAK_COMMON: | |
ead1e424 | 580 | // A common symbol is ignored in the face of a definition. |
86f2e683 | 581 | return false; |
ead1e424 | 582 | |
14bfc3f5 ILT |
583 | case UNDEF * 16 + DYN_WEAK_COMMON: |
584 | case WEAK_UNDEF * 16 + DYN_WEAK_COMMON: | |
585 | case DYN_UNDEF * 16 + DYN_WEAK_COMMON: | |
586 | case DYN_WEAK_UNDEF * 16 + DYN_WEAK_COMMON: | |
ead1e424 | 587 | // I guess a weak common symbol is better than a definition. |
86f2e683 | 588 | return true; |
ead1e424 | 589 | |
14bfc3f5 ILT |
590 | case COMMON * 16 + DYN_WEAK_COMMON: |
591 | case WEAK_COMMON * 16 + DYN_WEAK_COMMON: | |
592 | case DYN_COMMON * 16 + DYN_WEAK_COMMON: | |
593 | case DYN_WEAK_COMMON * 16 + DYN_WEAK_COMMON: | |
ead1e424 | 594 | // Set the size to the maximum. |
86f2e683 ILT |
595 | *adjust_common_sizes = true; |
596 | return false; | |
1564db8d ILT |
597 | |
598 | default: | |
a3ad94ed | 599 | gold_unreachable(); |
14bfc3f5 ILT |
600 | } |
601 | } | |
602 | ||
86f2e683 ILT |
603 | // A special case of should_override which is only called for a strong |
604 | // defined symbol from a regular object file. This is used when | |
605 | // defining special symbols. | |
606 | ||
607 | bool | |
608 | Symbol_table::should_override_with_special(const Symbol* to) | |
609 | { | |
610 | bool adjust_common_sizes; | |
611 | unsigned int frombits = global_flag | regular_flag | def_flag; | |
d20222a1 ILT |
612 | bool ret = Symbol_table::should_override(to, frombits, NULL, |
613 | &adjust_common_sizes); | |
86f2e683 ILT |
614 | gold_assert(!adjust_common_sizes); |
615 | return ret; | |
616 | } | |
617 | ||
618 | // Override symbol base with a special symbol. | |
619 | ||
620 | void | |
621 | Symbol::override_base_with_special(const Symbol* from) | |
622 | { | |
46fe1623 ILT |
623 | gold_assert(this->name_ == from->name_ || this->has_alias()); |
624 | ||
86f2e683 ILT |
625 | this->source_ = from->source_; |
626 | switch (from->source_) | |
627 | { | |
628 | case FROM_OBJECT: | |
629 | this->u_.from_object = from->u_.from_object; | |
630 | break; | |
631 | case IN_OUTPUT_DATA: | |
632 | this->u_.in_output_data = from->u_.in_output_data; | |
633 | break; | |
634 | case IN_OUTPUT_SEGMENT: | |
635 | this->u_.in_output_segment = from->u_.in_output_segment; | |
636 | break; | |
637 | case CONSTANT: | |
638 | break; | |
639 | default: | |
640 | gold_unreachable(); | |
641 | break; | |
642 | } | |
643 | ||
644 | if (from->version_ != NULL && this->version_ != from->version_) | |
645 | { | |
646 | gold_assert(this->version_ == NULL); | |
647 | this->version_ = from->version_; | |
648 | } | |
649 | ||
650 | this->type_ = from->type_; | |
651 | this->binding_ = from->binding_; | |
652 | this->visibility_ = from->visibility_; | |
653 | this->nonvis_ = from->nonvis_; | |
654 | ||
655 | // Special symbols are always considered to be regular symbols. | |
656 | this->in_reg_ = true; | |
46fe1623 ILT |
657 | |
658 | if (from->needs_dynsym_entry_) | |
659 | this->needs_dynsym_entry_ = true; | |
660 | if (from->needs_dynsym_value_) | |
661 | this->needs_dynsym_value_ = true; | |
662 | ||
663 | // We shouldn't see these flags. If we do, we need to handle them | |
664 | // somehow. | |
665 | gold_assert(!from->is_target_special_ || this->is_target_special_); | |
666 | gold_assert(!from->is_forwarder_); | |
667 | gold_assert(!from->has_got_offset_); | |
668 | gold_assert(!from->has_plt_offset_); | |
669 | gold_assert(!from->has_warning_); | |
670 | gold_assert(!from->is_copied_from_dynobj_); | |
86f2e683 ILT |
671 | } |
672 | ||
673 | // Override a symbol with a special symbol. | |
674 | ||
675 | template<int size> | |
676 | void | |
677 | Sized_symbol<size>::override_with_special(const Sized_symbol<size>* from) | |
678 | { | |
679 | this->override_base_with_special(from); | |
680 | this->value_ = from->value_; | |
681 | this->symsize_ = from->symsize_; | |
682 | } | |
683 | ||
aeddab66 ILT |
684 | // Override TOSYM with the special symbol FROMSYM. This handles all |
685 | // aliases of TOSYM. | |
686 | ||
687 | template<int size> | |
688 | void | |
689 | Symbol_table::override_with_special(Sized_symbol<size>* tosym, | |
690 | const Sized_symbol<size>* fromsym) | |
691 | { | |
692 | tosym->override_with_special(fromsym); | |
693 | if (tosym->has_alias()) | |
694 | { | |
695 | Symbol* sym = this->weak_aliases_[tosym]; | |
696 | gold_assert(sym != NULL); | |
697 | Sized_symbol<size>* ssym; | |
698 | ssym = this->get_sized_symbol SELECT_SIZE_NAME(size) (sym | |
699 | SELECT_SIZE(size)); | |
700 | do | |
701 | { | |
702 | ssym->override_with_special(fromsym); | |
703 | sym = this->weak_aliases_[ssym]; | |
704 | gold_assert(sym != NULL); | |
705 | ssym = this->get_sized_symbol SELECT_SIZE_NAME(size) ( | |
706 | sym SELECT_SIZE(size)); | |
707 | } | |
708 | while (ssym != tosym); | |
709 | } | |
710 | } | |
711 | ||
14bfc3f5 ILT |
712 | // Instantiate the templates we need. We could use the configure |
713 | // script to restrict this to only the ones needed for implemented | |
714 | // targets. | |
715 | ||
193a53d9 | 716 | #ifdef HAVE_TARGET_32_LITTLE |
14bfc3f5 ILT |
717 | template |
718 | void | |
193a53d9 | 719 | Symbol_table::resolve<32, false>( |
1564db8d | 720 | Sized_symbol<32>* to, |
193a53d9 | 721 | const elfcpp::Sym<32, false>& sym, |
14b31740 ILT |
722 | Object* object, |
723 | const char* version); | |
193a53d9 | 724 | #endif |
14bfc3f5 | 725 | |
193a53d9 | 726 | #ifdef HAVE_TARGET_32_BIG |
14bfc3f5 ILT |
727 | template |
728 | void | |
193a53d9 | 729 | Symbol_table::resolve<32, true>( |
1564db8d | 730 | Sized_symbol<32>* to, |
193a53d9 | 731 | const elfcpp::Sym<32, true>& sym, |
14b31740 ILT |
732 | Object* object, |
733 | const char* version); | |
193a53d9 | 734 | #endif |
14bfc3f5 | 735 | |
193a53d9 | 736 | #ifdef HAVE_TARGET_64_LITTLE |
14bfc3f5 ILT |
737 | template |
738 | void | |
193a53d9 | 739 | Symbol_table::resolve<64, false>( |
1564db8d | 740 | Sized_symbol<64>* to, |
193a53d9 | 741 | const elfcpp::Sym<64, false>& sym, |
14b31740 ILT |
742 | Object* object, |
743 | const char* version); | |
193a53d9 | 744 | #endif |
14bfc3f5 | 745 | |
193a53d9 | 746 | #ifdef HAVE_TARGET_64_BIG |
14bfc3f5 ILT |
747 | template |
748 | void | |
193a53d9 | 749 | Symbol_table::resolve<64, true>( |
1564db8d | 750 | Sized_symbol<64>* to, |
193a53d9 | 751 | const elfcpp::Sym<64, true>& sym, |
14b31740 ILT |
752 | Object* object, |
753 | const char* version); | |
193a53d9 | 754 | #endif |
14bfc3f5 | 755 | |
86f2e683 ILT |
756 | #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG) |
757 | template | |
758 | void | |
aeddab66 ILT |
759 | Symbol_table::override_with_special<32>(Sized_symbol<32>*, |
760 | const Sized_symbol<32>*); | |
86f2e683 ILT |
761 | #endif |
762 | ||
763 | #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG) | |
764 | template | |
765 | void | |
aeddab66 ILT |
766 | Symbol_table::override_with_special<64>(Sized_symbol<64>*, |
767 | const Sized_symbol<64>*); | |
86f2e683 ILT |
768 | #endif |
769 | ||
14bfc3f5 | 770 | } // End namespace gold. |