Commit | Line | Data |
---|---|---|
14bfc3f5 ILT |
1 | // resolve.cc -- symbol resolution for gold |
2 | ||
e5756efb | 3 | // Copyright 2006, 2007, 2008 Free Software Foundation, Inc. |
6cb15b7f ILT |
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" | |
89fc3421 | 29 | #include "plugin.h" |
14bfc3f5 ILT |
30 | |
31 | namespace gold | |
32 | { | |
33 | ||
1564db8d ILT |
34 | // Symbol methods used in this file. |
35 | ||
75517b77 ILT |
36 | // This symbol is being overridden by another symbol whose version is |
37 | // VERSION. Update the VERSION_ field accordingly. | |
38 | ||
39 | inline void | |
40 | Symbol::override_version(const char* version) | |
41 | { | |
42 | if (version == NULL) | |
43 | { | |
44 | // This is the case where this symbol is NAME/VERSION, and the | |
45 | // version was not marked as hidden. That makes it the default | |
46 | // version, so we create NAME/NULL. Later we see another symbol | |
47 | // NAME/NULL, and that symbol is overriding this one. In this | |
48 | // case, since NAME/VERSION is the default, we make NAME/NULL | |
49 | // override NAME/VERSION as well. They are already the same | |
50 | // Symbol structure. Setting the VERSION_ field to NULL ensures | |
51 | // that it will be output with the correct, empty, version. | |
52 | this->version_ = version; | |
53 | } | |
54 | else | |
55 | { | |
56 | // This is the case where this symbol is NAME/VERSION_ONE, and | |
57 | // now we see NAME/VERSION_TWO, and NAME/VERSION_TWO is | |
58 | // overriding NAME. If VERSION_ONE and VERSION_TWO are | |
59 | // different, then this can only happen when VERSION_ONE is NULL | |
60 | // and VERSION_TWO is not hidden. | |
61 | gold_assert(this->version_ == version || this->version_ == NULL); | |
62 | this->version_ = version; | |
63 | } | |
64 | } | |
65 | ||
1564db8d ILT |
66 | // Override the fields in Symbol. |
67 | ||
68 | template<int size, bool big_endian> | |
69 | void | |
70 | Symbol::override_base(const elfcpp::Sym<size, big_endian>& sym, | |
d491d34e | 71 | unsigned int st_shndx, bool is_ordinary, |
14b31740 | 72 | Object* object, const char* version) |
1564db8d | 73 | { |
a3ad94ed | 74 | gold_assert(this->source_ == FROM_OBJECT); |
ead1e424 | 75 | this->u_.from_object.object = object; |
75517b77 | 76 | this->override_version(version); |
d491d34e ILT |
77 | this->u_.from_object.shndx = st_shndx; |
78 | this->is_ordinary_shndx_ = is_ordinary; | |
1564db8d ILT |
79 | this->type_ = sym.get_st_type(); |
80 | this->binding_ = sym.get_st_bind(); | |
81 | this->visibility_ = sym.get_st_visibility(); | |
ead1e424 | 82 | this->nonvis_ = sym.get_st_nonvis(); |
0d4f1889 ILT |
83 | if (object->is_dynamic()) |
84 | this->in_dyn_ = true; | |
85 | else | |
86 | this->in_reg_ = true; | |
1564db8d ILT |
87 | } |
88 | ||
89 | // Override the fields in Sized_symbol. | |
90 | ||
91 | template<int size> | |
92 | template<bool big_endian> | |
93 | void | |
94 | Sized_symbol<size>::override(const elfcpp::Sym<size, big_endian>& sym, | |
d491d34e | 95 | unsigned st_shndx, bool is_ordinary, |
14b31740 | 96 | Object* object, const char* version) |
1564db8d | 97 | { |
d491d34e | 98 | this->override_base(sym, st_shndx, is_ordinary, object, version); |
1564db8d | 99 | this->value_ = sym.get_st_value(); |
ead1e424 | 100 | this->symsize_ = sym.get_st_size(); |
1564db8d ILT |
101 | } |
102 | ||
aeddab66 ILT |
103 | // Override TOSYM with symbol FROMSYM, defined in OBJECT, with version |
104 | // VERSION. This handles all aliases of TOSYM. | |
105 | ||
106 | template<int size, bool big_endian> | |
107 | void | |
108 | Symbol_table::override(Sized_symbol<size>* tosym, | |
109 | const elfcpp::Sym<size, big_endian>& fromsym, | |
d491d34e | 110 | unsigned int st_shndx, bool is_ordinary, |
aeddab66 ILT |
111 | Object* object, const char* version) |
112 | { | |
d491d34e | 113 | tosym->override(fromsym, st_shndx, is_ordinary, object, version); |
aeddab66 ILT |
114 | if (tosym->has_alias()) |
115 | { | |
116 | Symbol* sym = this->weak_aliases_[tosym]; | |
117 | gold_assert(sym != NULL); | |
7d1a9ebb | 118 | Sized_symbol<size>* ssym = this->get_sized_symbol<size>(sym); |
aeddab66 ILT |
119 | do |
120 | { | |
d491d34e | 121 | ssym->override(fromsym, st_shndx, is_ordinary, object, version); |
aeddab66 ILT |
122 | sym = this->weak_aliases_[ssym]; |
123 | gold_assert(sym != NULL); | |
7d1a9ebb | 124 | ssym = this->get_sized_symbol<size>(sym); |
aeddab66 ILT |
125 | } |
126 | while (ssym != tosym); | |
127 | } | |
128 | } | |
129 | ||
86f2e683 ILT |
130 | // The resolve functions build a little code for each symbol. |
131 | // Bit 0: 0 for global, 1 for weak. | |
132 | // Bit 1: 0 for regular object, 1 for shared object | |
133 | // Bits 2-3: 0 for normal, 1 for undefined, 2 for common | |
134 | // This gives us values from 0 to 11. | |
135 | ||
136 | static const int global_or_weak_shift = 0; | |
137 | static const unsigned int global_flag = 0 << global_or_weak_shift; | |
138 | static const unsigned int weak_flag = 1 << global_or_weak_shift; | |
139 | ||
140 | static const int regular_or_dynamic_shift = 1; | |
141 | static const unsigned int regular_flag = 0 << regular_or_dynamic_shift; | |
142 | static const unsigned int dynamic_flag = 1 << regular_or_dynamic_shift; | |
143 | ||
144 | static const int def_undef_or_common_shift = 2; | |
145 | static const unsigned int def_flag = 0 << def_undef_or_common_shift; | |
146 | static const unsigned int undef_flag = 1 << def_undef_or_common_shift; | |
147 | static const unsigned int common_flag = 2 << def_undef_or_common_shift; | |
148 | ||
70e654ba ILT |
149 | // This convenience function combines all the flags based on facts |
150 | // about the symbol. | |
151 | ||
152 | static unsigned int | |
153 | symbol_to_bits(elfcpp::STB binding, bool is_dynamic, | |
d491d34e | 154 | unsigned int shndx, bool is_ordinary, elfcpp::STT type) |
70e654ba ILT |
155 | { |
156 | unsigned int bits; | |
157 | ||
158 | switch (binding) | |
159 | { | |
160 | case elfcpp::STB_GLOBAL: | |
161 | bits = global_flag; | |
162 | break; | |
163 | ||
164 | case elfcpp::STB_WEAK: | |
165 | bits = weak_flag; | |
166 | break; | |
167 | ||
168 | case elfcpp::STB_LOCAL: | |
169 | // We should only see externally visible symbols in the symbol | |
170 | // table. | |
171 | gold_error(_("invalid STB_LOCAL symbol in external symbols")); | |
172 | bits = global_flag; | |
173 | ||
174 | default: | |
175 | // Any target which wants to handle STB_LOOS, etc., needs to | |
176 | // define a resolve method. | |
177 | gold_error(_("unsupported symbol binding")); | |
178 | bits = global_flag; | |
179 | } | |
180 | ||
181 | if (is_dynamic) | |
182 | bits |= dynamic_flag; | |
183 | else | |
184 | bits |= regular_flag; | |
185 | ||
186 | switch (shndx) | |
187 | { | |
188 | case elfcpp::SHN_UNDEF: | |
189 | bits |= undef_flag; | |
190 | break; | |
191 | ||
192 | case elfcpp::SHN_COMMON: | |
d491d34e ILT |
193 | if (!is_ordinary) |
194 | bits |= common_flag; | |
70e654ba ILT |
195 | break; |
196 | ||
197 | default: | |
198 | if (type == elfcpp::STT_COMMON) | |
199 | bits |= common_flag; | |
200 | else | |
201 | bits |= def_flag; | |
202 | break; | |
203 | } | |
204 | ||
205 | return bits; | |
206 | } | |
207 | ||
14bfc3f5 | 208 | // Resolve a symbol. This is called the second and subsequent times |
d491d34e ILT |
209 | // we see a symbol. TO is the pre-existing symbol. ST_SHNDX is the |
210 | // section index for SYM, possibly adjusted for many sections. | |
211 | // IS_ORDINARY is whether ST_SHNDX is a normal section index rather | |
212 | // than a special code. ORIG_ST_SHNDX is the original section index, | |
213 | // before any munging because of discarded sections, except that all | |
95d14cd3 | 214 | // non-ordinary section indexes are mapped to SHN_UNDEF. VERSION is |
d491d34e | 215 | // the version of SYM. |
14bfc3f5 ILT |
216 | |
217 | template<int size, bool big_endian> | |
218 | void | |
1564db8d | 219 | Symbol_table::resolve(Sized_symbol<size>* to, |
14bfc3f5 | 220 | const elfcpp::Sym<size, big_endian>& sym, |
d491d34e ILT |
221 | unsigned int st_shndx, bool is_ordinary, |
222 | unsigned int orig_st_shndx, | |
14b31740 | 223 | Object* object, const char* version) |
14bfc3f5 ILT |
224 | { |
225 | if (object->target()->has_resolve()) | |
226 | { | |
274e99f9 | 227 | Sized_target<size, big_endian>* sized_target; |
7d1a9ebb | 228 | sized_target = object->sized_target<size, big_endian>(); |
14b31740 | 229 | sized_target->resolve(to, sym, object, version); |
14bfc3f5 ILT |
230 | return; |
231 | } | |
232 | ||
86f2e683 ILT |
233 | if (!object->is_dynamic()) |
234 | { | |
235 | // Record that we've seen this symbol in a regular object. | |
236 | to->set_in_reg(); | |
237 | } | |
238 | else | |
239 | { | |
240 | // Record that we've seen this symbol in a dynamic object. | |
241 | to->set_in_dyn(); | |
242 | } | |
14bfc3f5 | 243 | |
89fc3421 CC |
244 | // Record if we've seen this symbol in a real ELF object (i.e., the |
245 | // symbol is referenced from outside the world known to the plugin). | |
246 | if (object->pluginobj() == NULL) | |
247 | to->set_in_real_elf(); | |
248 | ||
249 | // If we're processing replacement files, allow new symbols to override | |
250 | // the placeholders from the plugin objects. | |
251 | if (to->source() == Symbol::FROM_OBJECT) | |
252 | { | |
253 | Pluginobj* obj = to->object()->pluginobj(); | |
254 | if (obj != NULL | |
255 | && parameters->options().plugins()->in_replacement_phase()) | |
256 | { | |
257 | this->override(to, sym, st_shndx, is_ordinary, object, version); | |
258 | return; | |
259 | } | |
260 | } | |
261 | ||
70e654ba ILT |
262 | unsigned int frombits = symbol_to_bits(sym.get_st_bind(), |
263 | object->is_dynamic(), | |
d491d34e | 264 | st_shndx, is_ordinary, |
70e654ba | 265 | sym.get_st_type()); |
14bfc3f5 | 266 | |
86f2e683 | 267 | bool adjust_common_sizes; |
d20222a1 ILT |
268 | if (Symbol_table::should_override(to, frombits, object, |
269 | &adjust_common_sizes)) | |
86f2e683 ILT |
270 | { |
271 | typename Sized_symbol<size>::Size_type tosize = to->symsize(); | |
272 | ||
d491d34e | 273 | this->override(to, sym, st_shndx, is_ordinary, object, version); |
86f2e683 ILT |
274 | |
275 | if (adjust_common_sizes && tosize > to->symsize()) | |
276 | to->set_symsize(tosize); | |
277 | } | |
278 | else | |
279 | { | |
280 | if (adjust_common_sizes && sym.get_st_size() > to->symsize()) | |
281 | to->set_symsize(sym.get_st_size()); | |
282 | } | |
70e654ba ILT |
283 | |
284 | // A new weak undefined reference, merging with an old weak | |
285 | // reference, could be a One Definition Rule (ODR) violation -- | |
286 | // especially if the types or sizes of the references differ. We'll | |
287 | // store such pairs and look them up later to make sure they | |
288 | // actually refer to the same lines of code. (Note: not all ODR | |
289 | // violations can be found this way, and not everything this finds | |
290 | // is an ODR violation. But it's helpful to warn about.) | |
d491d34e | 291 | bool to_is_ordinary; |
8851ecca | 292 | if (parameters->options().detect_odr_violations() |
d491d34e | 293 | && sym.get_st_bind() == elfcpp::STB_WEAK |
70e654ba | 294 | && to->binding() == elfcpp::STB_WEAK |
d491d34e ILT |
295 | && orig_st_shndx != elfcpp::SHN_UNDEF |
296 | && to->shndx(&to_is_ordinary) != elfcpp::SHN_UNDEF | |
297 | && to_is_ordinary | |
298 | && sym.get_st_size() != 0 // Ignore weird 0-sized symbols. | |
70e654ba | 299 | && to->symsize() != 0 |
d491d34e ILT |
300 | && (sym.get_st_type() != to->type() |
301 | || sym.get_st_size() != to->symsize()) | |
70e654ba ILT |
302 | // C does not have a concept of ODR, so we only need to do this |
303 | // on C++ symbols. These have (mangled) names starting with _Z. | |
304 | && to->name()[0] == '_' && to->name()[1] == 'Z') | |
305 | { | |
a2b1aa12 | 306 | Symbol_location fromloc |
d491d34e ILT |
307 | = { object, orig_st_shndx, sym.get_st_value() }; |
308 | Symbol_location toloc = { to->object(), to->shndx(&to_is_ordinary), | |
309 | to->value() }; | |
a2b1aa12 ILT |
310 | this->candidate_odr_violations_[to->name()].insert(fromloc); |
311 | this->candidate_odr_violations_[to->name()].insert(toloc); | |
70e654ba | 312 | } |
86f2e683 ILT |
313 | } |
314 | ||
315 | // Handle the core of symbol resolution. This is called with the | |
316 | // existing symbol, TO, and a bitflag describing the new symbol. This | |
317 | // returns true if we should override the existing symbol with the new | |
318 | // one, and returns false otherwise. It sets *ADJUST_COMMON_SIZES to | |
319 | // true if we should set the symbol size to the maximum of the TO and | |
320 | // FROM sizes. It handles error conditions. | |
321 | ||
322 | bool | |
323 | Symbol_table::should_override(const Symbol* to, unsigned int frombits, | |
d20222a1 | 324 | Object* object, bool* adjust_common_sizes) |
86f2e683 ILT |
325 | { |
326 | *adjust_common_sizes = false; | |
327 | ||
e5756efb | 328 | unsigned int tobits; |
f3e9c5c5 ILT |
329 | if (to->source() == Symbol::IS_UNDEFINED) |
330 | tobits = symbol_to_bits(to->binding(), false, elfcpp::SHN_UNDEF, true, | |
331 | to->type()); | |
332 | else if (to->source() != Symbol::FROM_OBJECT) | |
d491d34e | 333 | tobits = symbol_to_bits(to->binding(), false, elfcpp::SHN_ABS, false, |
e5756efb ILT |
334 | to->type()); |
335 | else | |
d491d34e ILT |
336 | { |
337 | bool is_ordinary; | |
338 | unsigned int shndx = to->shndx(&is_ordinary); | |
339 | tobits = symbol_to_bits(to->binding(), | |
340 | to->object()->is_dynamic(), | |
341 | shndx, | |
342 | is_ordinary, | |
343 | to->type()); | |
344 | } | |
14bfc3f5 | 345 | |
1564db8d ILT |
346 | // FIXME: Warn if either but not both of TO and SYM are STT_TLS. |
347 | ||
14bfc3f5 ILT |
348 | // We use a giant switch table for symbol resolution. This code is |
349 | // unwieldy, but: 1) it is efficient; 2) we definitely handle all | |
350 | // cases; 3) it is easy to change the handling of a particular case. | |
351 | // The alternative would be a series of conditionals, but it is easy | |
352 | // to get the ordering wrong. This could also be done as a table, | |
353 | // but that is no easier to understand than this large switch | |
354 | // statement. | |
355 | ||
86f2e683 ILT |
356 | // These are the values generated by the bit codes. |
357 | enum | |
358 | { | |
359 | DEF = global_flag | regular_flag | def_flag, | |
360 | WEAK_DEF = weak_flag | regular_flag | def_flag, | |
361 | DYN_DEF = global_flag | dynamic_flag | def_flag, | |
362 | DYN_WEAK_DEF = weak_flag | dynamic_flag | def_flag, | |
363 | UNDEF = global_flag | regular_flag | undef_flag, | |
364 | WEAK_UNDEF = weak_flag | regular_flag | undef_flag, | |
365 | DYN_UNDEF = global_flag | dynamic_flag | undef_flag, | |
366 | DYN_WEAK_UNDEF = weak_flag | dynamic_flag | undef_flag, | |
367 | COMMON = global_flag | regular_flag | common_flag, | |
368 | WEAK_COMMON = weak_flag | regular_flag | common_flag, | |
369 | DYN_COMMON = global_flag | dynamic_flag | common_flag, | |
370 | DYN_WEAK_COMMON = weak_flag | dynamic_flag | common_flag | |
371 | }; | |
372 | ||
14bfc3f5 ILT |
373 | switch (tobits * 16 + frombits) |
374 | { | |
375 | case DEF * 16 + DEF: | |
12e14209 | 376 | // Two definitions of the same symbol. |
878405a8 ILT |
377 | |
378 | // If either symbol is defined by an object included using | |
379 | // --just-symbols, then don't warn. This is for compatibility | |
380 | // with the GNU linker. FIXME: This is a hack. | |
381 | if ((to->source() == Symbol::FROM_OBJECT && to->object()->just_symbols()) | |
382 | || object->just_symbols()) | |
383 | return false; | |
384 | ||
d20222a1 ILT |
385 | // FIXME: Do a better job of reporting locations. |
386 | gold_error(_("%s: multiple definition of %s"), | |
387 | object != NULL ? object->name().c_str() : _("command line"), | |
a2b1aa12 | 388 | to->demangled_name().c_str()); |
d20222a1 ILT |
389 | gold_error(_("%s: previous definition here"), |
390 | (to->source() == Symbol::FROM_OBJECT | |
391 | ? to->object()->name().c_str() | |
392 | : _("command line"))); | |
86f2e683 | 393 | return false; |
14bfc3f5 ILT |
394 | |
395 | case WEAK_DEF * 16 + DEF: | |
1564db8d ILT |
396 | // We've seen a weak definition, and now we see a strong |
397 | // definition. In the original SVR4 linker, this was treated as | |
398 | // a multiple definition error. In the Solaris linker and the | |
399 | // GNU linker, a weak definition followed by a regular | |
400 | // definition causes the weak definition to be overridden. We | |
401 | // are currently compatible with the GNU linker. In the future | |
402 | // we should add a target specific option to change this. | |
403 | // FIXME. | |
86f2e683 | 404 | return true; |
14bfc3f5 ILT |
405 | |
406 | case DYN_DEF * 16 + DEF: | |
407 | case DYN_WEAK_DEF * 16 + DEF: | |
1564db8d ILT |
408 | // We've seen a definition in a dynamic object, and now we see a |
409 | // definition in a regular object. The definition in the | |
410 | // regular object overrides the definition in the dynamic | |
411 | // object. | |
86f2e683 | 412 | return true; |
1564db8d | 413 | |
14bfc3f5 ILT |
414 | case UNDEF * 16 + DEF: |
415 | case WEAK_UNDEF * 16 + DEF: | |
416 | case DYN_UNDEF * 16 + DEF: | |
417 | case DYN_WEAK_UNDEF * 16 + DEF: | |
1564db8d ILT |
418 | // We've seen an undefined reference, and now we see a |
419 | // definition. We use the definition. | |
86f2e683 | 420 | return true; |
1564db8d | 421 | |
14bfc3f5 ILT |
422 | case COMMON * 16 + DEF: |
423 | case WEAK_COMMON * 16 + DEF: | |
424 | case DYN_COMMON * 16 + DEF: | |
425 | case DYN_WEAK_COMMON * 16 + DEF: | |
1564db8d | 426 | // We've seen a common symbol and now we see a definition. The |
14b31740 | 427 | // definition overrides. FIXME: We should optionally issue, version a |
1564db8d | 428 | // warning. |
86f2e683 | 429 | return true; |
14bfc3f5 ILT |
430 | |
431 | case DEF * 16 + WEAK_DEF: | |
432 | case WEAK_DEF * 16 + WEAK_DEF: | |
1564db8d ILT |
433 | // We've seen a definition and now we see a weak definition. We |
434 | // ignore the new weak definition. | |
86f2e683 | 435 | return false; |
1564db8d | 436 | |
14bfc3f5 ILT |
437 | case DYN_DEF * 16 + WEAK_DEF: |
438 | case DYN_WEAK_DEF * 16 + WEAK_DEF: | |
1564db8d ILT |
439 | // We've seen a dynamic definition and now we see a regular weak |
440 | // definition. The regular weak definition overrides. | |
86f2e683 | 441 | return true; |
1564db8d | 442 | |
14bfc3f5 ILT |
443 | case UNDEF * 16 + WEAK_DEF: |
444 | case WEAK_UNDEF * 16 + WEAK_DEF: | |
445 | case DYN_UNDEF * 16 + WEAK_DEF: | |
446 | case DYN_WEAK_UNDEF * 16 + WEAK_DEF: | |
1564db8d | 447 | // A weak definition of a currently undefined symbol. |
86f2e683 | 448 | return true; |
1564db8d | 449 | |
14bfc3f5 ILT |
450 | case COMMON * 16 + WEAK_DEF: |
451 | case WEAK_COMMON * 16 + WEAK_DEF: | |
1564db8d | 452 | // A weak definition does not override a common definition. |
86f2e683 | 453 | return false; |
1564db8d | 454 | |
14bfc3f5 ILT |
455 | case DYN_COMMON * 16 + WEAK_DEF: |
456 | case DYN_WEAK_COMMON * 16 + WEAK_DEF: | |
1564db8d ILT |
457 | // A weak definition does override a definition in a dynamic |
458 | // object. FIXME: We should optionally issue a warning. | |
86f2e683 | 459 | return true; |
14bfc3f5 ILT |
460 | |
461 | case DEF * 16 + DYN_DEF: | |
462 | case WEAK_DEF * 16 + DYN_DEF: | |
463 | case DYN_DEF * 16 + DYN_DEF: | |
464 | case DYN_WEAK_DEF * 16 + DYN_DEF: | |
1564db8d | 465 | // Ignore a dynamic definition if we already have a definition. |
86f2e683 | 466 | return false; |
1564db8d | 467 | |
14bfc3f5 ILT |
468 | case UNDEF * 16 + DYN_DEF: |
469 | case WEAK_UNDEF * 16 + DYN_DEF: | |
470 | case DYN_UNDEF * 16 + DYN_DEF: | |
471 | case DYN_WEAK_UNDEF * 16 + DYN_DEF: | |
1564db8d | 472 | // Use a dynamic definition if we have a reference. |
86f2e683 | 473 | return true; |
1564db8d | 474 | |
14bfc3f5 ILT |
475 | case COMMON * 16 + DYN_DEF: |
476 | case WEAK_COMMON * 16 + DYN_DEF: | |
477 | case DYN_COMMON * 16 + DYN_DEF: | |
478 | case DYN_WEAK_COMMON * 16 + DYN_DEF: | |
1564db8d ILT |
479 | // Ignore a dynamic definition if we already have a common |
480 | // definition. | |
86f2e683 | 481 | return false; |
14bfc3f5 ILT |
482 | |
483 | case DEF * 16 + DYN_WEAK_DEF: | |
484 | case WEAK_DEF * 16 + DYN_WEAK_DEF: | |
485 | case DYN_DEF * 16 + DYN_WEAK_DEF: | |
486 | case DYN_WEAK_DEF * 16 + DYN_WEAK_DEF: | |
1564db8d ILT |
487 | // Ignore a weak dynamic definition if we already have a |
488 | // definition. | |
86f2e683 | 489 | return false; |
1564db8d | 490 | |
14bfc3f5 ILT |
491 | case UNDEF * 16 + DYN_WEAK_DEF: |
492 | case WEAK_UNDEF * 16 + DYN_WEAK_DEF: | |
493 | case DYN_UNDEF * 16 + DYN_WEAK_DEF: | |
494 | case DYN_WEAK_UNDEF * 16 + DYN_WEAK_DEF: | |
1564db8d | 495 | // Use a weak dynamic definition if we have a reference. |
86f2e683 | 496 | return true; |
1564db8d | 497 | |
14bfc3f5 ILT |
498 | case COMMON * 16 + DYN_WEAK_DEF: |
499 | case WEAK_COMMON * 16 + DYN_WEAK_DEF: | |
500 | case DYN_COMMON * 16 + DYN_WEAK_DEF: | |
501 | case DYN_WEAK_COMMON * 16 + DYN_WEAK_DEF: | |
1564db8d ILT |
502 | // Ignore a weak dynamic definition if we already have a common |
503 | // definition. | |
86f2e683 | 504 | return false; |
14bfc3f5 ILT |
505 | |
506 | case DEF * 16 + UNDEF: | |
507 | case WEAK_DEF * 16 + UNDEF: | |
508 | case DYN_DEF * 16 + UNDEF: | |
509 | case DYN_WEAK_DEF * 16 + UNDEF: | |
510 | case UNDEF * 16 + UNDEF: | |
ead1e424 | 511 | // A new undefined reference tells us nothing. |
86f2e683 | 512 | return false; |
ead1e424 | 513 | |
14bfc3f5 ILT |
514 | case WEAK_UNDEF * 16 + UNDEF: |
515 | case DYN_UNDEF * 16 + UNDEF: | |
516 | case DYN_WEAK_UNDEF * 16 + UNDEF: | |
ead1e424 | 517 | // A strong undef overrides a dynamic or weak undef. |
86f2e683 | 518 | return true; |
ead1e424 | 519 | |
14bfc3f5 ILT |
520 | case COMMON * 16 + UNDEF: |
521 | case WEAK_COMMON * 16 + UNDEF: | |
522 | case DYN_COMMON * 16 + UNDEF: | |
523 | case DYN_WEAK_COMMON * 16 + UNDEF: | |
1564db8d | 524 | // A new undefined reference tells us nothing. |
86f2e683 | 525 | return false; |
14bfc3f5 ILT |
526 | |
527 | case DEF * 16 + WEAK_UNDEF: | |
528 | case WEAK_DEF * 16 + WEAK_UNDEF: | |
529 | case DYN_DEF * 16 + WEAK_UNDEF: | |
530 | case DYN_WEAK_DEF * 16 + WEAK_UNDEF: | |
531 | case UNDEF * 16 + WEAK_UNDEF: | |
532 | case WEAK_UNDEF * 16 + WEAK_UNDEF: | |
533 | case DYN_UNDEF * 16 + WEAK_UNDEF: | |
534 | case DYN_WEAK_UNDEF * 16 + WEAK_UNDEF: | |
535 | case COMMON * 16 + WEAK_UNDEF: | |
536 | case WEAK_COMMON * 16 + WEAK_UNDEF: | |
537 | case DYN_COMMON * 16 + WEAK_UNDEF: | |
538 | case DYN_WEAK_COMMON * 16 + WEAK_UNDEF: | |
1564db8d | 539 | // A new weak undefined reference tells us nothing. |
86f2e683 | 540 | return false; |
14bfc3f5 ILT |
541 | |
542 | case DEF * 16 + DYN_UNDEF: | |
543 | case WEAK_DEF * 16 + DYN_UNDEF: | |
544 | case DYN_DEF * 16 + DYN_UNDEF: | |
545 | case DYN_WEAK_DEF * 16 + DYN_UNDEF: | |
546 | case UNDEF * 16 + DYN_UNDEF: | |
547 | case WEAK_UNDEF * 16 + DYN_UNDEF: | |
548 | case DYN_UNDEF * 16 + DYN_UNDEF: | |
549 | case DYN_WEAK_UNDEF * 16 + DYN_UNDEF: | |
550 | case COMMON * 16 + DYN_UNDEF: | |
551 | case WEAK_COMMON * 16 + DYN_UNDEF: | |
552 | case DYN_COMMON * 16 + DYN_UNDEF: | |
553 | case DYN_WEAK_COMMON * 16 + DYN_UNDEF: | |
1564db8d | 554 | // A new dynamic undefined reference tells us nothing. |
86f2e683 | 555 | return false; |
14bfc3f5 ILT |
556 | |
557 | case DEF * 16 + DYN_WEAK_UNDEF: | |
558 | case WEAK_DEF * 16 + DYN_WEAK_UNDEF: | |
559 | case DYN_DEF * 16 + DYN_WEAK_UNDEF: | |
560 | case DYN_WEAK_DEF * 16 + DYN_WEAK_UNDEF: | |
561 | case UNDEF * 16 + DYN_WEAK_UNDEF: | |
562 | case WEAK_UNDEF * 16 + DYN_WEAK_UNDEF: | |
563 | case DYN_UNDEF * 16 + DYN_WEAK_UNDEF: | |
564 | case DYN_WEAK_UNDEF * 16 + DYN_WEAK_UNDEF: | |
565 | case COMMON * 16 + DYN_WEAK_UNDEF: | |
566 | case WEAK_COMMON * 16 + DYN_WEAK_UNDEF: | |
567 | case DYN_COMMON * 16 + DYN_WEAK_UNDEF: | |
568 | case DYN_WEAK_COMMON * 16 + DYN_WEAK_UNDEF: | |
1564db8d | 569 | // A new weak dynamic undefined reference tells us nothing. |
86f2e683 | 570 | return false; |
14bfc3f5 ILT |
571 | |
572 | case DEF * 16 + COMMON: | |
1564db8d | 573 | // A common symbol does not override a definition. |
86f2e683 | 574 | return false; |
1564db8d | 575 | |
14bfc3f5 ILT |
576 | case WEAK_DEF * 16 + COMMON: |
577 | case DYN_DEF * 16 + COMMON: | |
578 | case DYN_WEAK_DEF * 16 + COMMON: | |
1564db8d ILT |
579 | // A common symbol does override a weak definition or a dynamic |
580 | // definition. | |
86f2e683 | 581 | return true; |
1564db8d | 582 | |
14bfc3f5 ILT |
583 | case UNDEF * 16 + COMMON: |
584 | case WEAK_UNDEF * 16 + COMMON: | |
585 | case DYN_UNDEF * 16 + COMMON: | |
586 | case DYN_WEAK_UNDEF * 16 + COMMON: | |
1564db8d | 587 | // A common symbol is a definition for a reference. |
86f2e683 | 588 | return true; |
1564db8d | 589 | |
14bfc3f5 | 590 | case COMMON * 16 + COMMON: |
ead1e424 | 591 | // Set the size to the maximum. |
86f2e683 ILT |
592 | *adjust_common_sizes = true; |
593 | return false; | |
ead1e424 | 594 | |
14bfc3f5 | 595 | case WEAK_COMMON * 16 + COMMON: |
ead1e424 ILT |
596 | // I'm not sure just what a weak common symbol means, but |
597 | // presumably it can be overridden by a regular common symbol. | |
86f2e683 | 598 | return true; |
ead1e424 | 599 | |
14bfc3f5 ILT |
600 | case DYN_COMMON * 16 + COMMON: |
601 | case DYN_WEAK_COMMON * 16 + COMMON: | |
86f2e683 ILT |
602 | // Use the real common symbol, but adjust the size if necessary. |
603 | *adjust_common_sizes = true; | |
604 | return true; | |
14bfc3f5 ILT |
605 | |
606 | case DEF * 16 + WEAK_COMMON: | |
607 | case WEAK_DEF * 16 + WEAK_COMMON: | |
608 | case DYN_DEF * 16 + WEAK_COMMON: | |
609 | case DYN_WEAK_DEF * 16 + WEAK_COMMON: | |
ead1e424 ILT |
610 | // Whatever a weak common symbol is, it won't override a |
611 | // definition. | |
86f2e683 | 612 | return false; |
ead1e424 | 613 | |
14bfc3f5 ILT |
614 | case UNDEF * 16 + WEAK_COMMON: |
615 | case WEAK_UNDEF * 16 + WEAK_COMMON: | |
616 | case DYN_UNDEF * 16 + WEAK_COMMON: | |
617 | case DYN_WEAK_UNDEF * 16 + WEAK_COMMON: | |
ead1e424 | 618 | // A weak common symbol is better than an undefined symbol. |
86f2e683 | 619 | return true; |
ead1e424 | 620 | |
14bfc3f5 ILT |
621 | case COMMON * 16 + WEAK_COMMON: |
622 | case WEAK_COMMON * 16 + WEAK_COMMON: | |
623 | case DYN_COMMON * 16 + WEAK_COMMON: | |
624 | case DYN_WEAK_COMMON * 16 + WEAK_COMMON: | |
ead1e424 ILT |
625 | // Ignore a weak common symbol in the presence of a real common |
626 | // symbol. | |
86f2e683 | 627 | return false; |
14bfc3f5 ILT |
628 | |
629 | case DEF * 16 + DYN_COMMON: | |
630 | case WEAK_DEF * 16 + DYN_COMMON: | |
631 | case DYN_DEF * 16 + DYN_COMMON: | |
632 | case DYN_WEAK_DEF * 16 + DYN_COMMON: | |
ead1e424 ILT |
633 | // Ignore a dynamic common symbol in the presence of a |
634 | // definition. | |
86f2e683 | 635 | return false; |
ead1e424 | 636 | |
14bfc3f5 ILT |
637 | case UNDEF * 16 + DYN_COMMON: |
638 | case WEAK_UNDEF * 16 + DYN_COMMON: | |
639 | case DYN_UNDEF * 16 + DYN_COMMON: | |
640 | case DYN_WEAK_UNDEF * 16 + DYN_COMMON: | |
ead1e424 | 641 | // A dynamic common symbol is a definition of sorts. |
86f2e683 | 642 | return true; |
ead1e424 | 643 | |
14bfc3f5 ILT |
644 | case COMMON * 16 + DYN_COMMON: |
645 | case WEAK_COMMON * 16 + DYN_COMMON: | |
646 | case DYN_COMMON * 16 + DYN_COMMON: | |
647 | case DYN_WEAK_COMMON * 16 + DYN_COMMON: | |
ead1e424 | 648 | // Set the size to the maximum. |
86f2e683 ILT |
649 | *adjust_common_sizes = true; |
650 | return false; | |
14bfc3f5 ILT |
651 | |
652 | case DEF * 16 + DYN_WEAK_COMMON: | |
653 | case WEAK_DEF * 16 + DYN_WEAK_COMMON: | |
654 | case DYN_DEF * 16 + DYN_WEAK_COMMON: | |
655 | case DYN_WEAK_DEF * 16 + DYN_WEAK_COMMON: | |
ead1e424 | 656 | // A common symbol is ignored in the face of a definition. |
86f2e683 | 657 | return false; |
ead1e424 | 658 | |
14bfc3f5 ILT |
659 | case UNDEF * 16 + DYN_WEAK_COMMON: |
660 | case WEAK_UNDEF * 16 + DYN_WEAK_COMMON: | |
661 | case DYN_UNDEF * 16 + DYN_WEAK_COMMON: | |
662 | case DYN_WEAK_UNDEF * 16 + DYN_WEAK_COMMON: | |
ead1e424 | 663 | // I guess a weak common symbol is better than a definition. |
86f2e683 | 664 | return true; |
ead1e424 | 665 | |
14bfc3f5 ILT |
666 | case COMMON * 16 + DYN_WEAK_COMMON: |
667 | case WEAK_COMMON * 16 + DYN_WEAK_COMMON: | |
668 | case DYN_COMMON * 16 + DYN_WEAK_COMMON: | |
669 | case DYN_WEAK_COMMON * 16 + DYN_WEAK_COMMON: | |
ead1e424 | 670 | // Set the size to the maximum. |
86f2e683 ILT |
671 | *adjust_common_sizes = true; |
672 | return false; | |
1564db8d ILT |
673 | |
674 | default: | |
a3ad94ed | 675 | gold_unreachable(); |
14bfc3f5 ILT |
676 | } |
677 | } | |
678 | ||
86f2e683 ILT |
679 | // A special case of should_override which is only called for a strong |
680 | // defined symbol from a regular object file. This is used when | |
681 | // defining special symbols. | |
682 | ||
683 | bool | |
684 | Symbol_table::should_override_with_special(const Symbol* to) | |
685 | { | |
686 | bool adjust_common_sizes; | |
687 | unsigned int frombits = global_flag | regular_flag | def_flag; | |
d20222a1 ILT |
688 | bool ret = Symbol_table::should_override(to, frombits, NULL, |
689 | &adjust_common_sizes); | |
86f2e683 ILT |
690 | gold_assert(!adjust_common_sizes); |
691 | return ret; | |
692 | } | |
693 | ||
694 | // Override symbol base with a special symbol. | |
695 | ||
696 | void | |
697 | Symbol::override_base_with_special(const Symbol* from) | |
698 | { | |
46fe1623 ILT |
699 | gold_assert(this->name_ == from->name_ || this->has_alias()); |
700 | ||
86f2e683 ILT |
701 | this->source_ = from->source_; |
702 | switch (from->source_) | |
703 | { | |
704 | case FROM_OBJECT: | |
705 | this->u_.from_object = from->u_.from_object; | |
706 | break; | |
707 | case IN_OUTPUT_DATA: | |
708 | this->u_.in_output_data = from->u_.in_output_data; | |
709 | break; | |
710 | case IN_OUTPUT_SEGMENT: | |
711 | this->u_.in_output_segment = from->u_.in_output_segment; | |
712 | break; | |
f3e9c5c5 ILT |
713 | case IS_CONSTANT: |
714 | case IS_UNDEFINED: | |
86f2e683 ILT |
715 | break; |
716 | default: | |
717 | gold_unreachable(); | |
718 | break; | |
719 | } | |
720 | ||
75517b77 | 721 | this->override_version(from->version_); |
86f2e683 ILT |
722 | this->type_ = from->type_; |
723 | this->binding_ = from->binding_; | |
724 | this->visibility_ = from->visibility_; | |
725 | this->nonvis_ = from->nonvis_; | |
726 | ||
727 | // Special symbols are always considered to be regular symbols. | |
728 | this->in_reg_ = true; | |
46fe1623 ILT |
729 | |
730 | if (from->needs_dynsym_entry_) | |
731 | this->needs_dynsym_entry_ = true; | |
732 | if (from->needs_dynsym_value_) | |
733 | this->needs_dynsym_value_ = true; | |
734 | ||
735 | // We shouldn't see these flags. If we do, we need to handle them | |
736 | // somehow. | |
737 | gold_assert(!from->is_target_special_ || this->is_target_special_); | |
738 | gold_assert(!from->is_forwarder_); | |
46fe1623 ILT |
739 | gold_assert(!from->has_plt_offset_); |
740 | gold_assert(!from->has_warning_); | |
741 | gold_assert(!from->is_copied_from_dynobj_); | |
55a93433 | 742 | gold_assert(!from->is_forced_local_); |
86f2e683 ILT |
743 | } |
744 | ||
745 | // Override a symbol with a special symbol. | |
746 | ||
747 | template<int size> | |
748 | void | |
749 | Sized_symbol<size>::override_with_special(const Sized_symbol<size>* from) | |
750 | { | |
751 | this->override_base_with_special(from); | |
752 | this->value_ = from->value_; | |
753 | this->symsize_ = from->symsize_; | |
754 | } | |
755 | ||
aeddab66 ILT |
756 | // Override TOSYM with the special symbol FROMSYM. This handles all |
757 | // aliases of TOSYM. | |
758 | ||
759 | template<int size> | |
760 | void | |
761 | Symbol_table::override_with_special(Sized_symbol<size>* tosym, | |
762 | const Sized_symbol<size>* fromsym) | |
763 | { | |
764 | tosym->override_with_special(fromsym); | |
765 | if (tosym->has_alias()) | |
766 | { | |
767 | Symbol* sym = this->weak_aliases_[tosym]; | |
768 | gold_assert(sym != NULL); | |
7d1a9ebb | 769 | Sized_symbol<size>* ssym = this->get_sized_symbol<size>(sym); |
aeddab66 ILT |
770 | do |
771 | { | |
772 | ssym->override_with_special(fromsym); | |
773 | sym = this->weak_aliases_[ssym]; | |
774 | gold_assert(sym != NULL); | |
7d1a9ebb | 775 | ssym = this->get_sized_symbol<size>(sym); |
aeddab66 ILT |
776 | } |
777 | while (ssym != tosym); | |
778 | } | |
55a93433 ILT |
779 | if (tosym->binding() == elfcpp::STB_LOCAL) |
780 | this->force_local(tosym); | |
aeddab66 ILT |
781 | } |
782 | ||
14bfc3f5 ILT |
783 | // Instantiate the templates we need. We could use the configure |
784 | // script to restrict this to only the ones needed for implemented | |
785 | // targets. | |
786 | ||
193a53d9 | 787 | #ifdef HAVE_TARGET_32_LITTLE |
14bfc3f5 ILT |
788 | template |
789 | void | |
193a53d9 | 790 | Symbol_table::resolve<32, false>( |
1564db8d | 791 | Sized_symbol<32>* to, |
193a53d9 | 792 | const elfcpp::Sym<32, false>& sym, |
d491d34e ILT |
793 | unsigned int st_shndx, |
794 | bool is_ordinary, | |
795 | unsigned int orig_st_shndx, | |
14b31740 ILT |
796 | Object* object, |
797 | const char* version); | |
193a53d9 | 798 | #endif |
14bfc3f5 | 799 | |
193a53d9 | 800 | #ifdef HAVE_TARGET_32_BIG |
14bfc3f5 ILT |
801 | template |
802 | void | |
193a53d9 | 803 | Symbol_table::resolve<32, true>( |
1564db8d | 804 | Sized_symbol<32>* to, |
193a53d9 | 805 | const elfcpp::Sym<32, true>& sym, |
d491d34e ILT |
806 | unsigned int st_shndx, |
807 | bool is_ordinary, | |
808 | unsigned int orig_st_shndx, | |
14b31740 ILT |
809 | Object* object, |
810 | const char* version); | |
193a53d9 | 811 | #endif |
14bfc3f5 | 812 | |
193a53d9 | 813 | #ifdef HAVE_TARGET_64_LITTLE |
14bfc3f5 ILT |
814 | template |
815 | void | |
193a53d9 | 816 | Symbol_table::resolve<64, false>( |
1564db8d | 817 | Sized_symbol<64>* to, |
193a53d9 | 818 | const elfcpp::Sym<64, false>& sym, |
d491d34e ILT |
819 | unsigned int st_shndx, |
820 | bool is_ordinary, | |
821 | unsigned int orig_st_shndx, | |
14b31740 ILT |
822 | Object* object, |
823 | const char* version); | |
193a53d9 | 824 | #endif |
14bfc3f5 | 825 | |
193a53d9 | 826 | #ifdef HAVE_TARGET_64_BIG |
14bfc3f5 ILT |
827 | template |
828 | void | |
193a53d9 | 829 | Symbol_table::resolve<64, true>( |
1564db8d | 830 | Sized_symbol<64>* to, |
193a53d9 | 831 | const elfcpp::Sym<64, true>& sym, |
d491d34e ILT |
832 | unsigned int st_shndx, |
833 | bool is_ordinary, | |
834 | unsigned int orig_st_shndx, | |
14b31740 ILT |
835 | Object* object, |
836 | const char* version); | |
193a53d9 | 837 | #endif |
14bfc3f5 | 838 | |
86f2e683 ILT |
839 | #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG) |
840 | template | |
841 | void | |
aeddab66 ILT |
842 | Symbol_table::override_with_special<32>(Sized_symbol<32>*, |
843 | const Sized_symbol<32>*); | |
86f2e683 ILT |
844 | #endif |
845 | ||
846 | #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG) | |
847 | template | |
848 | void | |
aeddab66 ILT |
849 | Symbol_table::override_with_special<64>(Sized_symbol<64>*, |
850 | const Sized_symbol<64>*); | |
86f2e683 ILT |
851 | #endif |
852 | ||
14bfc3f5 | 853 | } // End namespace gold. |