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14bfc3f5 ILT |
1 | // resolve.cc -- symbol resolution for gold |
2 | ||
b90efa5b | 3 | // Copyright (C) 2006-2015 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 | |
2ea97941 | 40 | Symbol::override_version(const char* version) |
75517b77 | 41 | { |
2ea97941 | 42 | if (version == NULL) |
75517b77 ILT |
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. | |
2ea97941 | 52 | this->version_ = version; |
75517b77 ILT |
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. | |
2ea97941 ILT |
61 | gold_assert(this->version_ == version || this->version_ == NULL); |
62 | this->version_ = version; | |
75517b77 ILT |
63 | } |
64 | } | |
65 | ||
0602e05a ILT |
66 | // This symbol is being overidden by another symbol whose visibility |
67 | // is VISIBILITY. Updated the VISIBILITY_ field accordingly. | |
68 | ||
69 | inline void | |
2ea97941 | 70 | Symbol::override_visibility(elfcpp::STV visibility) |
0602e05a ILT |
71 | { |
72 | // The rule for combining visibility is that we always choose the | |
73 | // most constrained visibility. In order of increasing constraint, | |
74 | // visibility goes PROTECTED, HIDDEN, INTERNAL. This is the reverse | |
75 | // of the numeric values, so the effect is that we always want the | |
76 | // smallest non-zero value. | |
2ea97941 | 77 | if (visibility != elfcpp::STV_DEFAULT) |
0602e05a ILT |
78 | { |
79 | if (this->visibility_ == elfcpp::STV_DEFAULT) | |
2ea97941 ILT |
80 | this->visibility_ = visibility; |
81 | else if (this->visibility_ > visibility) | |
82 | this->visibility_ = visibility; | |
0602e05a ILT |
83 | } |
84 | } | |
85 | ||
1564db8d ILT |
86 | // Override the fields in Symbol. |
87 | ||
88 | template<int size, bool big_endian> | |
89 | void | |
90 | Symbol::override_base(const elfcpp::Sym<size, big_endian>& sym, | |
d491d34e | 91 | unsigned int st_shndx, bool is_ordinary, |
2ea97941 | 92 | Object* object, const char* version) |
1564db8d | 93 | { |
a3ad94ed | 94 | gold_assert(this->source_ == FROM_OBJECT); |
2ea97941 ILT |
95 | this->u_.from_object.object = object; |
96 | this->override_version(version); | |
d491d34e ILT |
97 | this->u_.from_object.shndx = st_shndx; |
98 | this->is_ordinary_shndx_ = is_ordinary; | |
32364e50 CC |
99 | // Don't override st_type from plugin placeholder symbols. |
100 | if (object->pluginobj() == NULL) | |
101 | this->type_ = sym.get_st_type(); | |
1564db8d | 102 | this->binding_ = sym.get_st_bind(); |
0602e05a | 103 | this->override_visibility(sym.get_st_visibility()); |
ead1e424 | 104 | this->nonvis_ = sym.get_st_nonvis(); |
2ea97941 | 105 | if (object->is_dynamic()) |
0d4f1889 ILT |
106 | this->in_dyn_ = true; |
107 | else | |
108 | this->in_reg_ = true; | |
1564db8d ILT |
109 | } |
110 | ||
111 | // Override the fields in Sized_symbol. | |
112 | ||
113 | template<int size> | |
114 | template<bool big_endian> | |
115 | void | |
116 | Sized_symbol<size>::override(const elfcpp::Sym<size, big_endian>& sym, | |
d491d34e | 117 | unsigned st_shndx, bool is_ordinary, |
2ea97941 | 118 | Object* object, const char* version) |
1564db8d | 119 | { |
2ea97941 | 120 | this->override_base(sym, st_shndx, is_ordinary, object, version); |
1564db8d | 121 | this->value_ = sym.get_st_value(); |
ead1e424 | 122 | this->symsize_ = sym.get_st_size(); |
1564db8d ILT |
123 | } |
124 | ||
aeddab66 ILT |
125 | // Override TOSYM with symbol FROMSYM, defined in OBJECT, with version |
126 | // VERSION. This handles all aliases of TOSYM. | |
127 | ||
128 | template<int size, bool big_endian> | |
129 | void | |
130 | Symbol_table::override(Sized_symbol<size>* tosym, | |
131 | const elfcpp::Sym<size, big_endian>& fromsym, | |
d491d34e | 132 | unsigned int st_shndx, bool is_ordinary, |
2ea97941 | 133 | Object* object, const char* version) |
aeddab66 | 134 | { |
2ea97941 | 135 | tosym->override(fromsym, st_shndx, is_ordinary, object, version); |
aeddab66 ILT |
136 | if (tosym->has_alias()) |
137 | { | |
138 | Symbol* sym = this->weak_aliases_[tosym]; | |
139 | gold_assert(sym != NULL); | |
7d1a9ebb | 140 | Sized_symbol<size>* ssym = this->get_sized_symbol<size>(sym); |
aeddab66 ILT |
141 | do |
142 | { | |
2ea97941 | 143 | ssym->override(fromsym, st_shndx, is_ordinary, object, version); |
aeddab66 ILT |
144 | sym = this->weak_aliases_[ssym]; |
145 | gold_assert(sym != NULL); | |
7d1a9ebb | 146 | ssym = this->get_sized_symbol<size>(sym); |
aeddab66 ILT |
147 | } |
148 | while (ssym != tosym); | |
149 | } | |
150 | } | |
151 | ||
86f2e683 ILT |
152 | // The resolve functions build a little code for each symbol. |
153 | // Bit 0: 0 for global, 1 for weak. | |
154 | // Bit 1: 0 for regular object, 1 for shared object | |
155 | // Bits 2-3: 0 for normal, 1 for undefined, 2 for common | |
156 | // This gives us values from 0 to 11. | |
157 | ||
158 | static const int global_or_weak_shift = 0; | |
159 | static const unsigned int global_flag = 0 << global_or_weak_shift; | |
160 | static const unsigned int weak_flag = 1 << global_or_weak_shift; | |
161 | ||
162 | static const int regular_or_dynamic_shift = 1; | |
163 | static const unsigned int regular_flag = 0 << regular_or_dynamic_shift; | |
164 | static const unsigned int dynamic_flag = 1 << regular_or_dynamic_shift; | |
165 | ||
166 | static const int def_undef_or_common_shift = 2; | |
167 | static const unsigned int def_flag = 0 << def_undef_or_common_shift; | |
168 | static const unsigned int undef_flag = 1 << def_undef_or_common_shift; | |
169 | static const unsigned int common_flag = 2 << def_undef_or_common_shift; | |
170 | ||
70e654ba ILT |
171 | // This convenience function combines all the flags based on facts |
172 | // about the symbol. | |
173 | ||
174 | static unsigned int | |
175 | symbol_to_bits(elfcpp::STB binding, bool is_dynamic, | |
b8cf5075 | 176 | unsigned int shndx, bool is_ordinary) |
70e654ba ILT |
177 | { |
178 | unsigned int bits; | |
179 | ||
180 | switch (binding) | |
181 | { | |
182 | case elfcpp::STB_GLOBAL: | |
adcf2816 | 183 | case elfcpp::STB_GNU_UNIQUE: |
70e654ba ILT |
184 | bits = global_flag; |
185 | break; | |
186 | ||
187 | case elfcpp::STB_WEAK: | |
188 | bits = weak_flag; | |
189 | break; | |
190 | ||
191 | case elfcpp::STB_LOCAL: | |
192 | // We should only see externally visible symbols in the symbol | |
193 | // table. | |
194 | gold_error(_("invalid STB_LOCAL symbol in external symbols")); | |
195 | bits = global_flag; | |
196 | ||
197 | default: | |
198 | // Any target which wants to handle STB_LOOS, etc., needs to | |
199 | // define a resolve method. | |
ac897c20 | 200 | gold_error(_("unsupported symbol binding %d"), static_cast<int>(binding)); |
70e654ba ILT |
201 | bits = global_flag; |
202 | } | |
203 | ||
204 | if (is_dynamic) | |
205 | bits |= dynamic_flag; | |
206 | else | |
207 | bits |= regular_flag; | |
208 | ||
209 | switch (shndx) | |
210 | { | |
211 | case elfcpp::SHN_UNDEF: | |
212 | bits |= undef_flag; | |
213 | break; | |
214 | ||
215 | case elfcpp::SHN_COMMON: | |
d491d34e ILT |
216 | if (!is_ordinary) |
217 | bits |= common_flag; | |
70e654ba ILT |
218 | break; |
219 | ||
220 | default: | |
b8cf5075 | 221 | if (!is_ordinary && Symbol::is_common_shndx(shndx)) |
8a5e3e08 | 222 | bits |= common_flag; |
70e654ba ILT |
223 | else |
224 | bits |= def_flag; | |
225 | break; | |
226 | } | |
227 | ||
228 | return bits; | |
229 | } | |
230 | ||
14bfc3f5 | 231 | // Resolve a symbol. This is called the second and subsequent times |
d491d34e ILT |
232 | // we see a symbol. TO is the pre-existing symbol. ST_SHNDX is the |
233 | // section index for SYM, possibly adjusted for many sections. | |
234 | // IS_ORDINARY is whether ST_SHNDX is a normal section index rather | |
235 | // than a special code. ORIG_ST_SHNDX is the original section index, | |
236 | // before any munging because of discarded sections, except that all | |
95d14cd3 | 237 | // non-ordinary section indexes are mapped to SHN_UNDEF. VERSION is |
d491d34e | 238 | // the version of SYM. |
14bfc3f5 ILT |
239 | |
240 | template<int size, bool big_endian> | |
241 | void | |
1564db8d | 242 | Symbol_table::resolve(Sized_symbol<size>* to, |
14bfc3f5 | 243 | const elfcpp::Sym<size, big_endian>& sym, |
d491d34e ILT |
244 | unsigned int st_shndx, bool is_ordinary, |
245 | unsigned int orig_st_shndx, | |
14b31740 | 246 | Object* object, const char* version) |
14bfc3f5 | 247 | { |
534b4e5f ILT |
248 | // It's possible for a symbol to be defined in an object file |
249 | // using .symver to give it a version, and for there to also be | |
250 | // a linker script giving that symbol the same version. We | |
251 | // don't want to give a multiple-definition error for this | |
252 | // harmless redefinition. | |
253 | bool to_is_ordinary; | |
254 | if (to->source() == Symbol::FROM_OBJECT | |
255 | && to->object() == object | |
256 | && is_ordinary | |
257 | && to->is_defined() | |
258 | && to->shndx(&to_is_ordinary) == st_shndx | |
259 | && to_is_ordinary | |
260 | && to->value() == sym.get_st_value()) | |
261 | return; | |
262 | ||
029ba973 | 263 | if (parameters->target().has_resolve()) |
14bfc3f5 | 264 | { |
274e99f9 | 265 | Sized_target<size, big_endian>* sized_target; |
029ba973 | 266 | sized_target = parameters->sized_target<size, big_endian>(); |
14b31740 | 267 | sized_target->resolve(to, sym, object, version); |
14bfc3f5 ILT |
268 | return; |
269 | } | |
270 | ||
86f2e683 ILT |
271 | if (!object->is_dynamic()) |
272 | { | |
b8cf5075 CC |
273 | if (sym.get_st_type() == elfcpp::STT_COMMON |
274 | && (is_ordinary || !Symbol::is_common_shndx(st_shndx))) | |
275 | { | |
276 | gold_warning(_("STT_COMMON symbol '%s' in %s " | |
277 | "is not in a common section"), | |
278 | to->demangled_name().c_str(), | |
279 | to->object()->name().c_str()); | |
280 | return; | |
281 | } | |
86f2e683 ILT |
282 | // Record that we've seen this symbol in a regular object. |
283 | to->set_in_reg(); | |
284 | } | |
2da73f13 CC |
285 | else if (st_shndx == elfcpp::SHN_UNDEF |
286 | && (to->visibility() == elfcpp::STV_HIDDEN | |
287 | || to->visibility() == elfcpp::STV_INTERNAL)) | |
645afe0c | 288 | { |
c20ceeb2 YW |
289 | // The symbol is hidden, so a reference from a shared object |
290 | // cannot bind to it. We tried issuing a warning in this case, | |
291 | // but that produces false positives when the symbol is | |
292 | // actually resolved in a different shared object (PR 15574). | |
645afe0c CC |
293 | return; |
294 | } | |
86f2e683 ILT |
295 | else |
296 | { | |
297 | // Record that we've seen this symbol in a dynamic object. | |
298 | to->set_in_dyn(); | |
299 | } | |
14bfc3f5 | 300 | |
89fc3421 CC |
301 | // Record if we've seen this symbol in a real ELF object (i.e., the |
302 | // symbol is referenced from outside the world known to the plugin). | |
f7c5b166 | 303 | if (object->pluginobj() == NULL && !object->is_dynamic()) |
89fc3421 CC |
304 | to->set_in_real_elf(); |
305 | ||
306 | // If we're processing replacement files, allow new symbols to override | |
307 | // the placeholders from the plugin objects. | |
6168c2a1 RÁE |
308 | // Treat common symbols specially since it is possible that an ELF |
309 | // file increased the size of the alignment. | |
89fc3421 CC |
310 | if (to->source() == Symbol::FROM_OBJECT) |
311 | { | |
312 | Pluginobj* obj = to->object()->pluginobj(); | |
313 | if (obj != NULL | |
1707f183 | 314 | && parameters->options().plugins()->in_replacement_phase()) |
89fc3421 | 315 | { |
1707f183 CC |
316 | bool adjust_common = false; |
317 | typename Sized_symbol<size>::Size_type tosize = 0; | |
318 | typename Sized_symbol<size>::Value_type tovalue = 0; | |
b8cf5075 CC |
319 | if (to->is_common() |
320 | && !is_ordinary && Symbol::is_common_shndx(st_shndx)) | |
1707f183 CC |
321 | { |
322 | adjust_common = true; | |
db4c9594 CC |
323 | tosize = to->symsize(); |
324 | tovalue = to->value(); | |
1707f183 CC |
325 | } |
326 | this->override(to, sym, st_shndx, is_ordinary, object, version); | |
327 | if (adjust_common) | |
328 | { | |
329 | if (tosize > to->symsize()) | |
330 | to->set_symsize(tosize); | |
331 | if (tovalue > to->value()) | |
332 | to->set_value(tovalue); | |
333 | } | |
334 | return; | |
89fc3421 CC |
335 | } |
336 | } | |
337 | ||
ba4d53bf ILT |
338 | // A new weak undefined reference, merging with an old weak |
339 | // reference, could be a One Definition Rule (ODR) violation -- | |
340 | // especially if the types or sizes of the references differ. We'll | |
341 | // store such pairs and look them up later to make sure they | |
342 | // actually refer to the same lines of code. We also check | |
343 | // combinations of weak and strong, which might occur if one case is | |
344 | // inline and the other is not. (Note: not all ODR violations can | |
345 | // be found this way, and not everything this finds is an ODR | |
346 | // violation. But it's helpful to warn about.) | |
ba4d53bf ILT |
347 | if (parameters->options().detect_odr_violations() |
348 | && (sym.get_st_bind() == elfcpp::STB_WEAK | |
349 | || to->binding() == elfcpp::STB_WEAK) | |
350 | && orig_st_shndx != elfcpp::SHN_UNDEF | |
351 | && to->shndx(&to_is_ordinary) != elfcpp::SHN_UNDEF | |
352 | && to_is_ordinary | |
353 | && sym.get_st_size() != 0 // Ignore weird 0-sized symbols. | |
354 | && to->symsize() != 0 | |
355 | && (sym.get_st_type() != to->type() | |
356 | || sym.get_st_size() != to->symsize()) | |
357 | // C does not have a concept of ODR, so we only need to do this | |
358 | // on C++ symbols. These have (mangled) names starting with _Z. | |
359 | && to->name()[0] == '_' && to->name()[1] == 'Z') | |
360 | { | |
361 | Symbol_location fromloc | |
76677ad0 | 362 | = { object, orig_st_shndx, static_cast<off_t>(sym.get_st_value()) }; |
ba4d53bf | 363 | Symbol_location toloc = { to->object(), to->shndx(&to_is_ordinary), |
76677ad0 | 364 | static_cast<off_t>(to->value()) }; |
ba4d53bf ILT |
365 | this->candidate_odr_violations_[to->name()].insert(fromloc); |
366 | this->candidate_odr_violations_[to->name()].insert(toloc); | |
367 | } | |
368 | ||
32364e50 CC |
369 | // Plugins don't provide a symbol type, so adopt the existing type |
370 | // if the FROM symbol is from a plugin. | |
371 | elfcpp::STT fromtype = (object->pluginobj() != NULL | |
372 | ? to->type() | |
373 | : sym.get_st_type()); | |
70e654ba ILT |
374 | unsigned int frombits = symbol_to_bits(sym.get_st_bind(), |
375 | object->is_dynamic(), | |
b8cf5075 | 376 | st_shndx, is_ordinary); |
14bfc3f5 | 377 | |
86f2e683 | 378 | bool adjust_common_sizes; |
ce279a62 | 379 | bool adjust_dyndef; |
1ae4d23b | 380 | typename Sized_symbol<size>::Size_type tosize = to->symsize(); |
32364e50 | 381 | if (Symbol_table::should_override(to, frombits, fromtype, OBJECT, |
62855347 | 382 | object, &adjust_common_sizes, |
ce279a62 | 383 | &adjust_dyndef)) |
86f2e683 | 384 | { |
ce279a62 | 385 | elfcpp::STB tobinding = to->binding(); |
fd325007 | 386 | typename Sized_symbol<size>::Value_type tovalue = to->value(); |
d491d34e | 387 | this->override(to, sym, st_shndx, is_ordinary, object, version); |
fd325007 ILT |
388 | if (adjust_common_sizes) |
389 | { | |
390 | if (tosize > to->symsize()) | |
391 | to->set_symsize(tosize); | |
392 | if (tovalue > to->value()) | |
393 | to->set_value(tovalue); | |
394 | } | |
ce279a62 CC |
395 | if (adjust_dyndef) |
396 | { | |
397 | // We are overriding an UNDEF or WEAK UNDEF with a DYN DEF. | |
398 | // Remember which kind of UNDEF it was for future reference. | |
399 | to->set_undef_binding(tobinding); | |
400 | } | |
86f2e683 ILT |
401 | } |
402 | else | |
403 | { | |
fd325007 ILT |
404 | if (adjust_common_sizes) |
405 | { | |
406 | if (sym.get_st_size() > tosize) | |
407 | to->set_symsize(sym.get_st_size()); | |
408 | if (sym.get_st_value() > to->value()) | |
409 | to->set_value(sym.get_st_value()); | |
410 | } | |
ce279a62 CC |
411 | if (adjust_dyndef) |
412 | { | |
413 | // We are keeping a DYN DEF after seeing an UNDEF or WEAK UNDEF. | |
414 | // Remember which kind of UNDEF it was. | |
415 | to->set_undef_binding(sym.get_st_bind()); | |
416 | } | |
0602e05a ILT |
417 | // The ELF ABI says that even for a reference to a symbol we |
418 | // merge the visibility. | |
419 | to->override_visibility(sym.get_st_visibility()); | |
86f2e683 | 420 | } |
70e654ba | 421 | |
1ae4d23b ILT |
422 | if (adjust_common_sizes && parameters->options().warn_common()) |
423 | { | |
424 | if (tosize > sym.get_st_size()) | |
425 | Symbol_table::report_resolve_problem(false, | |
426 | _("common of '%s' overriding " | |
427 | "smaller common"), | |
99fff23b | 428 | to, OBJECT, object); |
1ae4d23b ILT |
429 | else if (tosize < sym.get_st_size()) |
430 | Symbol_table::report_resolve_problem(false, | |
431 | _("common of '%s' overidden by " | |
432 | "larger common"), | |
99fff23b | 433 | to, OBJECT, object); |
1ae4d23b ILT |
434 | else |
435 | Symbol_table::report_resolve_problem(false, | |
436 | _("multiple common of '%s'"), | |
99fff23b | 437 | to, OBJECT, object); |
1ae4d23b | 438 | } |
86f2e683 ILT |
439 | } |
440 | ||
441 | // Handle the core of symbol resolution. This is called with the | |
442 | // existing symbol, TO, and a bitflag describing the new symbol. This | |
443 | // returns true if we should override the existing symbol with the new | |
444 | // one, and returns false otherwise. It sets *ADJUST_COMMON_SIZES to | |
445 | // true if we should set the symbol size to the maximum of the TO and | |
446 | // FROM sizes. It handles error conditions. | |
447 | ||
448 | bool | |
449 | Symbol_table::should_override(const Symbol* to, unsigned int frombits, | |
62855347 ILT |
450 | elfcpp::STT fromtype, Defined defined, |
451 | Object* object, bool* adjust_common_sizes, | |
ce279a62 | 452 | bool* adjust_dyndef) |
86f2e683 ILT |
453 | { |
454 | *adjust_common_sizes = false; | |
ce279a62 | 455 | *adjust_dyndef = false; |
86f2e683 | 456 | |
e5756efb | 457 | unsigned int tobits; |
f3e9c5c5 | 458 | if (to->source() == Symbol::IS_UNDEFINED) |
b8cf5075 | 459 | tobits = symbol_to_bits(to->binding(), false, elfcpp::SHN_UNDEF, true); |
f3e9c5c5 | 460 | else if (to->source() != Symbol::FROM_OBJECT) |
b8cf5075 | 461 | tobits = symbol_to_bits(to->binding(), false, elfcpp::SHN_ABS, false); |
e5756efb | 462 | else |
d491d34e ILT |
463 | { |
464 | bool is_ordinary; | |
465 | unsigned int shndx = to->shndx(&is_ordinary); | |
466 | tobits = symbol_to_bits(to->binding(), | |
467 | to->object()->is_dynamic(), | |
468 | shndx, | |
b8cf5075 | 469 | is_ordinary); |
d491d34e | 470 | } |
14bfc3f5 | 471 | |
32364e50 CC |
472 | if ((to->type() == elfcpp::STT_TLS) ^ (fromtype == elfcpp::STT_TLS) |
473 | && !to->is_placeholder()) | |
62855347 ILT |
474 | Symbol_table::report_resolve_problem(true, |
475 | _("symbol '%s' used as both __thread " | |
476 | "and non-__thread"), | |
477 | to, defined, object); | |
1564db8d | 478 | |
14bfc3f5 ILT |
479 | // We use a giant switch table for symbol resolution. This code is |
480 | // unwieldy, but: 1) it is efficient; 2) we definitely handle all | |
481 | // cases; 3) it is easy to change the handling of a particular case. | |
482 | // The alternative would be a series of conditionals, but it is easy | |
483 | // to get the ordering wrong. This could also be done as a table, | |
484 | // but that is no easier to understand than this large switch | |
485 | // statement. | |
486 | ||
86f2e683 ILT |
487 | // These are the values generated by the bit codes. |
488 | enum | |
489 | { | |
490 | DEF = global_flag | regular_flag | def_flag, | |
491 | WEAK_DEF = weak_flag | regular_flag | def_flag, | |
492 | DYN_DEF = global_flag | dynamic_flag | def_flag, | |
493 | DYN_WEAK_DEF = weak_flag | dynamic_flag | def_flag, | |
494 | UNDEF = global_flag | regular_flag | undef_flag, | |
495 | WEAK_UNDEF = weak_flag | regular_flag | undef_flag, | |
496 | DYN_UNDEF = global_flag | dynamic_flag | undef_flag, | |
497 | DYN_WEAK_UNDEF = weak_flag | dynamic_flag | undef_flag, | |
498 | COMMON = global_flag | regular_flag | common_flag, | |
499 | WEAK_COMMON = weak_flag | regular_flag | common_flag, | |
500 | DYN_COMMON = global_flag | dynamic_flag | common_flag, | |
501 | DYN_WEAK_COMMON = weak_flag | dynamic_flag | common_flag | |
502 | }; | |
503 | ||
14bfc3f5 ILT |
504 | switch (tobits * 16 + frombits) |
505 | { | |
506 | case DEF * 16 + DEF: | |
12e14209 | 507 | // Two definitions of the same symbol. |
878405a8 ILT |
508 | |
509 | // If either symbol is defined by an object included using | |
510 | // --just-symbols, then don't warn. This is for compatibility | |
511 | // with the GNU linker. FIXME: This is a hack. | |
512 | if ((to->source() == Symbol::FROM_OBJECT && to->object()->just_symbols()) | |
99fff23b | 513 | || (object != NULL && object->just_symbols())) |
878405a8 ILT |
514 | return false; |
515 | ||
9c4ae156 | 516 | if (!parameters->options().muldefs()) |
30bc8c46 ILT |
517 | Symbol_table::report_resolve_problem(true, |
518 | _("multiple definition of '%s'"), | |
519 | to, defined, object); | |
86f2e683 | 520 | return false; |
14bfc3f5 ILT |
521 | |
522 | case WEAK_DEF * 16 + DEF: | |
1564db8d ILT |
523 | // We've seen a weak definition, and now we see a strong |
524 | // definition. In the original SVR4 linker, this was treated as | |
525 | // a multiple definition error. In the Solaris linker and the | |
526 | // GNU linker, a weak definition followed by a regular | |
527 | // definition causes the weak definition to be overridden. We | |
528 | // are currently compatible with the GNU linker. In the future | |
529 | // we should add a target specific option to change this. | |
530 | // FIXME. | |
86f2e683 | 531 | return true; |
14bfc3f5 ILT |
532 | |
533 | case DYN_DEF * 16 + DEF: | |
534 | case DYN_WEAK_DEF * 16 + DEF: | |
1564db8d ILT |
535 | // We've seen a definition in a dynamic object, and now we see a |
536 | // definition in a regular object. The definition in the | |
537 | // regular object overrides the definition in the dynamic | |
538 | // object. | |
86f2e683 | 539 | return true; |
1564db8d | 540 | |
14bfc3f5 ILT |
541 | case UNDEF * 16 + DEF: |
542 | case WEAK_UNDEF * 16 + DEF: | |
543 | case DYN_UNDEF * 16 + DEF: | |
544 | case DYN_WEAK_UNDEF * 16 + DEF: | |
1564db8d ILT |
545 | // We've seen an undefined reference, and now we see a |
546 | // definition. We use the definition. | |
86f2e683 | 547 | return true; |
1564db8d | 548 | |
14bfc3f5 ILT |
549 | case COMMON * 16 + DEF: |
550 | case WEAK_COMMON * 16 + DEF: | |
551 | case DYN_COMMON * 16 + DEF: | |
552 | case DYN_WEAK_COMMON * 16 + DEF: | |
1564db8d | 553 | // We've seen a common symbol and now we see a definition. The |
1ae4d23b ILT |
554 | // definition overrides. |
555 | if (parameters->options().warn_common()) | |
556 | Symbol_table::report_resolve_problem(false, | |
557 | _("definition of '%s' overriding " | |
558 | "common"), | |
99fff23b | 559 | to, defined, object); |
86f2e683 | 560 | return true; |
14bfc3f5 ILT |
561 | |
562 | case DEF * 16 + WEAK_DEF: | |
563 | case WEAK_DEF * 16 + WEAK_DEF: | |
1564db8d ILT |
564 | // We've seen a definition and now we see a weak definition. We |
565 | // ignore the new weak definition. | |
86f2e683 | 566 | return false; |
1564db8d | 567 | |
14bfc3f5 ILT |
568 | case DYN_DEF * 16 + WEAK_DEF: |
569 | case DYN_WEAK_DEF * 16 + WEAK_DEF: | |
1564db8d ILT |
570 | // We've seen a dynamic definition and now we see a regular weak |
571 | // definition. The regular weak definition overrides. | |
86f2e683 | 572 | return true; |
1564db8d | 573 | |
14bfc3f5 ILT |
574 | case UNDEF * 16 + WEAK_DEF: |
575 | case WEAK_UNDEF * 16 + WEAK_DEF: | |
576 | case DYN_UNDEF * 16 + WEAK_DEF: | |
577 | case DYN_WEAK_UNDEF * 16 + WEAK_DEF: | |
1564db8d | 578 | // A weak definition of a currently undefined symbol. |
86f2e683 | 579 | return true; |
1564db8d | 580 | |
14bfc3f5 ILT |
581 | case COMMON * 16 + WEAK_DEF: |
582 | case WEAK_COMMON * 16 + WEAK_DEF: | |
1564db8d | 583 | // A weak definition does not override a common definition. |
86f2e683 | 584 | return false; |
1564db8d | 585 | |
14bfc3f5 ILT |
586 | case DYN_COMMON * 16 + WEAK_DEF: |
587 | case DYN_WEAK_COMMON * 16 + WEAK_DEF: | |
1564db8d | 588 | // A weak definition does override a definition in a dynamic |
1ae4d23b ILT |
589 | // object. |
590 | if (parameters->options().warn_common()) | |
591 | Symbol_table::report_resolve_problem(false, | |
592 | _("definition of '%s' overriding " | |
593 | "dynamic common definition"), | |
99fff23b | 594 | to, defined, object); |
86f2e683 | 595 | return true; |
14bfc3f5 ILT |
596 | |
597 | case DEF * 16 + DYN_DEF: | |
598 | case WEAK_DEF * 16 + DYN_DEF: | |
599 | case DYN_DEF * 16 + DYN_DEF: | |
600 | case DYN_WEAK_DEF * 16 + DYN_DEF: | |
1564db8d | 601 | // Ignore a dynamic definition if we already have a definition. |
86f2e683 | 602 | return false; |
1564db8d | 603 | |
14bfc3f5 | 604 | case UNDEF * 16 + DYN_DEF: |
14bfc3f5 ILT |
605 | case DYN_UNDEF * 16 + DYN_DEF: |
606 | case DYN_WEAK_UNDEF * 16 + DYN_DEF: | |
1564db8d | 607 | // Use a dynamic definition if we have a reference. |
86f2e683 | 608 | return true; |
1564db8d | 609 | |
ce279a62 CC |
610 | case WEAK_UNDEF * 16 + DYN_DEF: |
611 | // When overriding a weak undef by a dynamic definition, | |
612 | // we need to remember that the original undef was weak. | |
613 | *adjust_dyndef = true; | |
614 | return true; | |
615 | ||
14bfc3f5 ILT |
616 | case COMMON * 16 + DYN_DEF: |
617 | case WEAK_COMMON * 16 + DYN_DEF: | |
618 | case DYN_COMMON * 16 + DYN_DEF: | |
619 | case DYN_WEAK_COMMON * 16 + DYN_DEF: | |
1564db8d ILT |
620 | // Ignore a dynamic definition if we already have a common |
621 | // definition. | |
86f2e683 | 622 | return false; |
14bfc3f5 ILT |
623 | |
624 | case DEF * 16 + DYN_WEAK_DEF: | |
625 | case WEAK_DEF * 16 + DYN_WEAK_DEF: | |
626 | case DYN_DEF * 16 + DYN_WEAK_DEF: | |
627 | case DYN_WEAK_DEF * 16 + DYN_WEAK_DEF: | |
1564db8d ILT |
628 | // Ignore a weak dynamic definition if we already have a |
629 | // definition. | |
86f2e683 | 630 | return false; |
1564db8d | 631 | |
14bfc3f5 | 632 | case UNDEF * 16 + DYN_WEAK_DEF: |
74f67560 DK |
633 | // When overriding an undef by a dynamic weak definition, |
634 | // we need to remember that the original undef was not weak. | |
635 | *adjust_dyndef = true; | |
636 | return true; | |
637 | ||
14bfc3f5 ILT |
638 | case DYN_UNDEF * 16 + DYN_WEAK_DEF: |
639 | case DYN_WEAK_UNDEF * 16 + DYN_WEAK_DEF: | |
1564db8d | 640 | // Use a weak dynamic definition if we have a reference. |
86f2e683 | 641 | return true; |
1564db8d | 642 | |
ce279a62 CC |
643 | case WEAK_UNDEF * 16 + DYN_WEAK_DEF: |
644 | // When overriding a weak undef by a dynamic definition, | |
645 | // we need to remember that the original undef was weak. | |
646 | *adjust_dyndef = true; | |
647 | return true; | |
648 | ||
14bfc3f5 ILT |
649 | case COMMON * 16 + DYN_WEAK_DEF: |
650 | case WEAK_COMMON * 16 + DYN_WEAK_DEF: | |
651 | case DYN_COMMON * 16 + DYN_WEAK_DEF: | |
652 | case DYN_WEAK_COMMON * 16 + DYN_WEAK_DEF: | |
1564db8d ILT |
653 | // Ignore a weak dynamic definition if we already have a common |
654 | // definition. | |
86f2e683 | 655 | return false; |
14bfc3f5 ILT |
656 | |
657 | case DEF * 16 + UNDEF: | |
658 | case WEAK_DEF * 16 + UNDEF: | |
14bfc3f5 | 659 | case UNDEF * 16 + UNDEF: |
ead1e424 | 660 | // A new undefined reference tells us nothing. |
86f2e683 | 661 | return false; |
ead1e424 | 662 | |
ce279a62 CC |
663 | case DYN_DEF * 16 + UNDEF: |
664 | case DYN_WEAK_DEF * 16 + UNDEF: | |
665 | // For a dynamic def, we need to remember which kind of undef we see. | |
666 | *adjust_dyndef = true; | |
667 | return false; | |
668 | ||
14bfc3f5 ILT |
669 | case WEAK_UNDEF * 16 + UNDEF: |
670 | case DYN_UNDEF * 16 + UNDEF: | |
671 | case DYN_WEAK_UNDEF * 16 + UNDEF: | |
ead1e424 | 672 | // A strong undef overrides a dynamic or weak undef. |
86f2e683 | 673 | return true; |
ead1e424 | 674 | |
14bfc3f5 ILT |
675 | case COMMON * 16 + UNDEF: |
676 | case WEAK_COMMON * 16 + UNDEF: | |
677 | case DYN_COMMON * 16 + UNDEF: | |
678 | case DYN_WEAK_COMMON * 16 + UNDEF: | |
1564db8d | 679 | // A new undefined reference tells us nothing. |
86f2e683 | 680 | return false; |
14bfc3f5 ILT |
681 | |
682 | case DEF * 16 + WEAK_UNDEF: | |
683 | case WEAK_DEF * 16 + WEAK_UNDEF: | |
14bfc3f5 ILT |
684 | case UNDEF * 16 + WEAK_UNDEF: |
685 | case WEAK_UNDEF * 16 + WEAK_UNDEF: | |
686 | case DYN_UNDEF * 16 + WEAK_UNDEF: | |
14bfc3f5 ILT |
687 | case COMMON * 16 + WEAK_UNDEF: |
688 | case WEAK_COMMON * 16 + WEAK_UNDEF: | |
689 | case DYN_COMMON * 16 + WEAK_UNDEF: | |
690 | case DYN_WEAK_COMMON * 16 + WEAK_UNDEF: | |
a4649286 DK |
691 | // A new weak undefined reference tells us nothing unless the |
692 | // exisiting symbol is a dynamic weak reference. | |
86f2e683 | 693 | return false; |
14bfc3f5 | 694 | |
a4649286 DK |
695 | case DYN_WEAK_UNDEF * 16 + WEAK_UNDEF: |
696 | // A new weak reference overrides an existing dynamic weak reference. | |
697 | // This is necessary because a dynamic weak reference remembers | |
698 | // the old binding, which may not be weak. If we keeps the existing | |
699 | // dynamic weak reference, the weakness may be dropped in the output. | |
700 | return true; | |
701 | ||
ce279a62 CC |
702 | case DYN_DEF * 16 + WEAK_UNDEF: |
703 | case DYN_WEAK_DEF * 16 + WEAK_UNDEF: | |
704 | // For a dynamic def, we need to remember which kind of undef we see. | |
705 | *adjust_dyndef = true; | |
706 | return false; | |
707 | ||
14bfc3f5 ILT |
708 | case DEF * 16 + DYN_UNDEF: |
709 | case WEAK_DEF * 16 + DYN_UNDEF: | |
710 | case DYN_DEF * 16 + DYN_UNDEF: | |
711 | case DYN_WEAK_DEF * 16 + DYN_UNDEF: | |
712 | case UNDEF * 16 + DYN_UNDEF: | |
713 | case WEAK_UNDEF * 16 + DYN_UNDEF: | |
714 | case DYN_UNDEF * 16 + DYN_UNDEF: | |
715 | case DYN_WEAK_UNDEF * 16 + DYN_UNDEF: | |
716 | case COMMON * 16 + DYN_UNDEF: | |
717 | case WEAK_COMMON * 16 + DYN_UNDEF: | |
718 | case DYN_COMMON * 16 + DYN_UNDEF: | |
719 | case DYN_WEAK_COMMON * 16 + DYN_UNDEF: | |
1564db8d | 720 | // A new dynamic undefined reference tells us nothing. |
86f2e683 | 721 | return false; |
14bfc3f5 ILT |
722 | |
723 | case DEF * 16 + DYN_WEAK_UNDEF: | |
724 | case WEAK_DEF * 16 + DYN_WEAK_UNDEF: | |
725 | case DYN_DEF * 16 + DYN_WEAK_UNDEF: | |
726 | case DYN_WEAK_DEF * 16 + DYN_WEAK_UNDEF: | |
727 | case UNDEF * 16 + DYN_WEAK_UNDEF: | |
728 | case WEAK_UNDEF * 16 + DYN_WEAK_UNDEF: | |
729 | case DYN_UNDEF * 16 + DYN_WEAK_UNDEF: | |
730 | case DYN_WEAK_UNDEF * 16 + DYN_WEAK_UNDEF: | |
731 | case COMMON * 16 + DYN_WEAK_UNDEF: | |
732 | case WEAK_COMMON * 16 + DYN_WEAK_UNDEF: | |
733 | case DYN_COMMON * 16 + DYN_WEAK_UNDEF: | |
734 | case DYN_WEAK_COMMON * 16 + DYN_WEAK_UNDEF: | |
1564db8d | 735 | // A new weak dynamic undefined reference tells us nothing. |
86f2e683 | 736 | return false; |
14bfc3f5 ILT |
737 | |
738 | case DEF * 16 + COMMON: | |
1564db8d | 739 | // A common symbol does not override a definition. |
1ae4d23b ILT |
740 | if (parameters->options().warn_common()) |
741 | Symbol_table::report_resolve_problem(false, | |
742 | _("common '%s' overridden by " | |
743 | "previous definition"), | |
99fff23b | 744 | to, defined, object); |
86f2e683 | 745 | return false; |
1564db8d | 746 | |
14bfc3f5 ILT |
747 | case WEAK_DEF * 16 + COMMON: |
748 | case DYN_DEF * 16 + COMMON: | |
749 | case DYN_WEAK_DEF * 16 + COMMON: | |
1564db8d ILT |
750 | // A common symbol does override a weak definition or a dynamic |
751 | // definition. | |
86f2e683 | 752 | return true; |
1564db8d | 753 | |
14bfc3f5 ILT |
754 | case UNDEF * 16 + COMMON: |
755 | case WEAK_UNDEF * 16 + COMMON: | |
756 | case DYN_UNDEF * 16 + COMMON: | |
757 | case DYN_WEAK_UNDEF * 16 + COMMON: | |
1564db8d | 758 | // A common symbol is a definition for a reference. |
86f2e683 | 759 | return true; |
1564db8d | 760 | |
14bfc3f5 | 761 | case COMMON * 16 + COMMON: |
ead1e424 | 762 | // Set the size to the maximum. |
86f2e683 ILT |
763 | *adjust_common_sizes = true; |
764 | return false; | |
ead1e424 | 765 | |
14bfc3f5 | 766 | case WEAK_COMMON * 16 + COMMON: |
ead1e424 ILT |
767 | // I'm not sure just what a weak common symbol means, but |
768 | // presumably it can be overridden by a regular common symbol. | |
86f2e683 | 769 | return true; |
ead1e424 | 770 | |
14bfc3f5 ILT |
771 | case DYN_COMMON * 16 + COMMON: |
772 | case DYN_WEAK_COMMON * 16 + COMMON: | |
86f2e683 ILT |
773 | // Use the real common symbol, but adjust the size if necessary. |
774 | *adjust_common_sizes = true; | |
775 | return true; | |
14bfc3f5 ILT |
776 | |
777 | case DEF * 16 + WEAK_COMMON: | |
778 | case WEAK_DEF * 16 + WEAK_COMMON: | |
779 | case DYN_DEF * 16 + WEAK_COMMON: | |
780 | case DYN_WEAK_DEF * 16 + WEAK_COMMON: | |
ead1e424 ILT |
781 | // Whatever a weak common symbol is, it won't override a |
782 | // definition. | |
86f2e683 | 783 | return false; |
ead1e424 | 784 | |
14bfc3f5 ILT |
785 | case UNDEF * 16 + WEAK_COMMON: |
786 | case WEAK_UNDEF * 16 + WEAK_COMMON: | |
787 | case DYN_UNDEF * 16 + WEAK_COMMON: | |
788 | case DYN_WEAK_UNDEF * 16 + WEAK_COMMON: | |
ead1e424 | 789 | // A weak common symbol is better than an undefined symbol. |
86f2e683 | 790 | return true; |
ead1e424 | 791 | |
14bfc3f5 ILT |
792 | case COMMON * 16 + WEAK_COMMON: |
793 | case WEAK_COMMON * 16 + WEAK_COMMON: | |
794 | case DYN_COMMON * 16 + WEAK_COMMON: | |
795 | case DYN_WEAK_COMMON * 16 + WEAK_COMMON: | |
ead1e424 ILT |
796 | // Ignore a weak common symbol in the presence of a real common |
797 | // symbol. | |
86f2e683 | 798 | return false; |
14bfc3f5 ILT |
799 | |
800 | case DEF * 16 + DYN_COMMON: | |
801 | case WEAK_DEF * 16 + DYN_COMMON: | |
802 | case DYN_DEF * 16 + DYN_COMMON: | |
803 | case DYN_WEAK_DEF * 16 + DYN_COMMON: | |
ead1e424 ILT |
804 | // Ignore a dynamic common symbol in the presence of a |
805 | // definition. | |
86f2e683 | 806 | return false; |
ead1e424 | 807 | |
14bfc3f5 ILT |
808 | case UNDEF * 16 + DYN_COMMON: |
809 | case WEAK_UNDEF * 16 + DYN_COMMON: | |
810 | case DYN_UNDEF * 16 + DYN_COMMON: | |
811 | case DYN_WEAK_UNDEF * 16 + DYN_COMMON: | |
ead1e424 | 812 | // A dynamic common symbol is a definition of sorts. |
86f2e683 | 813 | return true; |
ead1e424 | 814 | |
14bfc3f5 ILT |
815 | case COMMON * 16 + DYN_COMMON: |
816 | case WEAK_COMMON * 16 + DYN_COMMON: | |
817 | case DYN_COMMON * 16 + DYN_COMMON: | |
818 | case DYN_WEAK_COMMON * 16 + DYN_COMMON: | |
ead1e424 | 819 | // Set the size to the maximum. |
86f2e683 ILT |
820 | *adjust_common_sizes = true; |
821 | return false; | |
14bfc3f5 ILT |
822 | |
823 | case DEF * 16 + DYN_WEAK_COMMON: | |
824 | case WEAK_DEF * 16 + DYN_WEAK_COMMON: | |
825 | case DYN_DEF * 16 + DYN_WEAK_COMMON: | |
826 | case DYN_WEAK_DEF * 16 + DYN_WEAK_COMMON: | |
ead1e424 | 827 | // A common symbol is ignored in the face of a definition. |
86f2e683 | 828 | return false; |
ead1e424 | 829 | |
14bfc3f5 ILT |
830 | case UNDEF * 16 + DYN_WEAK_COMMON: |
831 | case WEAK_UNDEF * 16 + DYN_WEAK_COMMON: | |
832 | case DYN_UNDEF * 16 + DYN_WEAK_COMMON: | |
833 | case DYN_WEAK_UNDEF * 16 + DYN_WEAK_COMMON: | |
ead1e424 | 834 | // I guess a weak common symbol is better than a definition. |
86f2e683 | 835 | return true; |
ead1e424 | 836 | |
14bfc3f5 ILT |
837 | case COMMON * 16 + DYN_WEAK_COMMON: |
838 | case WEAK_COMMON * 16 + DYN_WEAK_COMMON: | |
839 | case DYN_COMMON * 16 + DYN_WEAK_COMMON: | |
840 | case DYN_WEAK_COMMON * 16 + DYN_WEAK_COMMON: | |
ead1e424 | 841 | // Set the size to the maximum. |
86f2e683 ILT |
842 | *adjust_common_sizes = true; |
843 | return false; | |
1564db8d ILT |
844 | |
845 | default: | |
a3ad94ed | 846 | gold_unreachable(); |
14bfc3f5 ILT |
847 | } |
848 | } | |
849 | ||
1ae4d23b ILT |
850 | // Issue an error or warning due to symbol resolution. IS_ERROR |
851 | // indicates an error rather than a warning. MSG is the error | |
852 | // message; it is expected to have a %s for the symbol name. TO is | |
99fff23b ILT |
853 | // the existing symbol. DEFINED/OBJECT is where the new symbol was |
854 | // found. | |
1ae4d23b ILT |
855 | |
856 | // FIXME: We should have better location information here. When the | |
857 | // symbol is defined, we should be able to pull the location from the | |
858 | // debug info if there is any. | |
859 | ||
860 | void | |
861 | Symbol_table::report_resolve_problem(bool is_error, const char* msg, | |
99fff23b ILT |
862 | const Symbol* to, Defined defined, |
863 | Object* object) | |
1ae4d23b ILT |
864 | { |
865 | std::string demangled(to->demangled_name()); | |
866 | size_t len = strlen(msg) + demangled.length() + 10; | |
867 | char* buf = new char[len]; | |
868 | snprintf(buf, len, msg, demangled.c_str()); | |
869 | ||
870 | const char* objname; | |
99fff23b ILT |
871 | switch (defined) |
872 | { | |
873 | case OBJECT: | |
874 | objname = object->name().c_str(); | |
875 | break; | |
876 | case COPY: | |
877 | objname = _("COPY reloc"); | |
878 | break; | |
879 | case DEFSYM: | |
880 | case UNDEFINED: | |
881 | objname = _("command line"); | |
882 | break; | |
883 | case SCRIPT: | |
884 | objname = _("linker script"); | |
885 | break; | |
886 | case PREDEFINED: | |
5146f448 | 887 | case INCREMENTAL_BASE: |
99fff23b ILT |
888 | objname = _("linker defined"); |
889 | break; | |
890 | default: | |
891 | gold_unreachable(); | |
892 | } | |
1ae4d23b ILT |
893 | |
894 | if (is_error) | |
895 | gold_error("%s: %s", objname, buf); | |
896 | else | |
897 | gold_warning("%s: %s", objname, buf); | |
898 | ||
899 | delete[] buf; | |
900 | ||
901 | if (to->source() == Symbol::FROM_OBJECT) | |
902 | objname = to->object()->name().c_str(); | |
903 | else | |
904 | objname = _("command line"); | |
905 | gold_info("%s: %s: previous definition here", program_name, objname); | |
906 | } | |
907 | ||
86f2e683 ILT |
908 | // A special case of should_override which is only called for a strong |
909 | // defined symbol from a regular object file. This is used when | |
910 | // defining special symbols. | |
911 | ||
912 | bool | |
62855347 ILT |
913 | Symbol_table::should_override_with_special(const Symbol* to, |
914 | elfcpp::STT fromtype, | |
915 | Defined defined) | |
86f2e683 ILT |
916 | { |
917 | bool adjust_common_sizes; | |
ce279a62 | 918 | bool adjust_dyn_def; |
86f2e683 | 919 | unsigned int frombits = global_flag | regular_flag | def_flag; |
62855347 ILT |
920 | bool ret = Symbol_table::should_override(to, frombits, fromtype, defined, |
921 | NULL, &adjust_common_sizes, | |
ce279a62 CC |
922 | &adjust_dyn_def); |
923 | gold_assert(!adjust_common_sizes && !adjust_dyn_def); | |
86f2e683 ILT |
924 | return ret; |
925 | } | |
926 | ||
927 | // Override symbol base with a special symbol. | |
928 | ||
929 | void | |
930 | Symbol::override_base_with_special(const Symbol* from) | |
931 | { | |
21131061 ILT |
932 | bool same_name = this->name_ == from->name_; |
933 | gold_assert(same_name || this->has_alias()); | |
46fe1623 | 934 | |
d1bddd3c CC |
935 | // If we are overriding an undef, remember the original binding. |
936 | if (this->is_undefined()) | |
937 | this->set_undef_binding(this->binding_); | |
938 | ||
86f2e683 ILT |
939 | this->source_ = from->source_; |
940 | switch (from->source_) | |
941 | { | |
942 | case FROM_OBJECT: | |
943 | this->u_.from_object = from->u_.from_object; | |
944 | break; | |
945 | case IN_OUTPUT_DATA: | |
946 | this->u_.in_output_data = from->u_.in_output_data; | |
947 | break; | |
948 | case IN_OUTPUT_SEGMENT: | |
949 | this->u_.in_output_segment = from->u_.in_output_segment; | |
950 | break; | |
f3e9c5c5 ILT |
951 | case IS_CONSTANT: |
952 | case IS_UNDEFINED: | |
86f2e683 ILT |
953 | break; |
954 | default: | |
955 | gold_unreachable(); | |
956 | break; | |
957 | } | |
958 | ||
21131061 | 959 | if (same_name) |
24d47b34 ILT |
960 | { |
961 | // When overriding a versioned symbol with a special symbol, we | |
962 | // may be changing the version. This will happen if we see a | |
963 | // special symbol such as "_end" defined in a shared object with | |
964 | // one version (from a version script), but we want to define it | |
965 | // here with a different version (from a different version | |
966 | // script). | |
967 | this->version_ = from->version_; | |
968 | } | |
86f2e683 ILT |
969 | this->type_ = from->type_; |
970 | this->binding_ = from->binding_; | |
0602e05a | 971 | this->override_visibility(from->visibility_); |
86f2e683 ILT |
972 | this->nonvis_ = from->nonvis_; |
973 | ||
974 | // Special symbols are always considered to be regular symbols. | |
975 | this->in_reg_ = true; | |
46fe1623 ILT |
976 | |
977 | if (from->needs_dynsym_entry_) | |
978 | this->needs_dynsym_entry_ = true; | |
979 | if (from->needs_dynsym_value_) | |
980 | this->needs_dynsym_value_ = true; | |
981 | ||
5146f448 CC |
982 | this->is_predefined_ = from->is_predefined_; |
983 | ||
46fe1623 ILT |
984 | // We shouldn't see these flags. If we do, we need to handle them |
985 | // somehow. | |
46fe1623 | 986 | gold_assert(!from->is_forwarder_); |
880cd20d | 987 | gold_assert(!from->has_plt_offset()); |
46fe1623 ILT |
988 | gold_assert(!from->has_warning_); |
989 | gold_assert(!from->is_copied_from_dynobj_); | |
55a93433 | 990 | gold_assert(!from->is_forced_local_); |
86f2e683 ILT |
991 | } |
992 | ||
993 | // Override a symbol with a special symbol. | |
994 | ||
995 | template<int size> | |
996 | void | |
997 | Sized_symbol<size>::override_with_special(const Sized_symbol<size>* from) | |
998 | { | |
999 | this->override_base_with_special(from); | |
1000 | this->value_ = from->value_; | |
1001 | this->symsize_ = from->symsize_; | |
1002 | } | |
1003 | ||
aeddab66 ILT |
1004 | // Override TOSYM with the special symbol FROMSYM. This handles all |
1005 | // aliases of TOSYM. | |
1006 | ||
1007 | template<int size> | |
1008 | void | |
1009 | Symbol_table::override_with_special(Sized_symbol<size>* tosym, | |
1010 | const Sized_symbol<size>* fromsym) | |
1011 | { | |
1012 | tosym->override_with_special(fromsym); | |
1013 | if (tosym->has_alias()) | |
1014 | { | |
1015 | Symbol* sym = this->weak_aliases_[tosym]; | |
1016 | gold_assert(sym != NULL); | |
7d1a9ebb | 1017 | Sized_symbol<size>* ssym = this->get_sized_symbol<size>(sym); |
aeddab66 ILT |
1018 | do |
1019 | { | |
1020 | ssym->override_with_special(fromsym); | |
1021 | sym = this->weak_aliases_[ssym]; | |
1022 | gold_assert(sym != NULL); | |
7d1a9ebb | 1023 | ssym = this->get_sized_symbol<size>(sym); |
aeddab66 ILT |
1024 | } |
1025 | while (ssym != tosym); | |
1026 | } | |
0602e05a ILT |
1027 | if (tosym->binding() == elfcpp::STB_LOCAL |
1028 | || ((tosym->visibility() == elfcpp::STV_HIDDEN | |
1029 | || tosym->visibility() == elfcpp::STV_INTERNAL) | |
1030 | && (tosym->binding() == elfcpp::STB_GLOBAL | |
adcf2816 | 1031 | || tosym->binding() == elfcpp::STB_GNU_UNIQUE |
0602e05a ILT |
1032 | || tosym->binding() == elfcpp::STB_WEAK) |
1033 | && !parameters->options().relocatable())) | |
55a93433 | 1034 | this->force_local(tosym); |
aeddab66 ILT |
1035 | } |
1036 | ||
14bfc3f5 ILT |
1037 | // Instantiate the templates we need. We could use the configure |
1038 | // script to restrict this to only the ones needed for implemented | |
1039 | // targets. | |
1040 | ||
6cfaf60b DK |
1041 | // We have to instantiate both big and little endian versions because |
1042 | // these are used by other templates that depends on size only. | |
1043 | ||
1044 | #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG) | |
14bfc3f5 ILT |
1045 | template |
1046 | void | |
193a53d9 | 1047 | Symbol_table::resolve<32, false>( |
1564db8d | 1048 | Sized_symbol<32>* to, |
193a53d9 | 1049 | const elfcpp::Sym<32, false>& sym, |
d491d34e ILT |
1050 | unsigned int st_shndx, |
1051 | bool is_ordinary, | |
1052 | unsigned int orig_st_shndx, | |
14b31740 ILT |
1053 | Object* object, |
1054 | const char* version); | |
14bfc3f5 ILT |
1055 | |
1056 | template | |
1057 | void | |
193a53d9 | 1058 | Symbol_table::resolve<32, true>( |
1564db8d | 1059 | Sized_symbol<32>* to, |
193a53d9 | 1060 | const elfcpp::Sym<32, true>& sym, |
d491d34e ILT |
1061 | unsigned int st_shndx, |
1062 | bool is_ordinary, | |
1063 | unsigned int orig_st_shndx, | |
14b31740 ILT |
1064 | Object* object, |
1065 | const char* version); | |
193a53d9 | 1066 | #endif |
14bfc3f5 | 1067 | |
6cfaf60b | 1068 | #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG) |
14bfc3f5 ILT |
1069 | template |
1070 | void | |
193a53d9 | 1071 | Symbol_table::resolve<64, false>( |
1564db8d | 1072 | Sized_symbol<64>* to, |
193a53d9 | 1073 | const elfcpp::Sym<64, false>& sym, |
d491d34e ILT |
1074 | unsigned int st_shndx, |
1075 | bool is_ordinary, | |
1076 | unsigned int orig_st_shndx, | |
14b31740 ILT |
1077 | Object* object, |
1078 | const char* version); | |
14bfc3f5 ILT |
1079 | |
1080 | template | |
1081 | void | |
193a53d9 | 1082 | Symbol_table::resolve<64, true>( |
1564db8d | 1083 | Sized_symbol<64>* to, |
193a53d9 | 1084 | const elfcpp::Sym<64, true>& sym, |
d491d34e ILT |
1085 | unsigned int st_shndx, |
1086 | bool is_ordinary, | |
1087 | unsigned int orig_st_shndx, | |
14b31740 ILT |
1088 | Object* object, |
1089 | const char* version); | |
193a53d9 | 1090 | #endif |
14bfc3f5 | 1091 | |
86f2e683 ILT |
1092 | #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG) |
1093 | template | |
1094 | void | |
aeddab66 ILT |
1095 | Symbol_table::override_with_special<32>(Sized_symbol<32>*, |
1096 | const Sized_symbol<32>*); | |
86f2e683 ILT |
1097 | #endif |
1098 | ||
1099 | #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG) | |
1100 | template | |
1101 | void | |
aeddab66 ILT |
1102 | Symbol_table::override_with_special<64>(Sized_symbol<64>*, |
1103 | const Sized_symbol<64>*); | |
86f2e683 ILT |
1104 | #endif |
1105 | ||
14bfc3f5 | 1106 | } // End namespace gold. |