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14bfc3f5 ILT |
1 | // resolve.cc -- symbol resolution for gold |
2 | ||
4b95cf5c | 3 | // Copyright (C) 2006-2014 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, | |
d491d34e | 176 | unsigned int shndx, bool is_ordinary, elfcpp::STT type) |
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: | |
221 | if (type == elfcpp::STT_COMMON) | |
222 | bits |= common_flag; | |
8a5e3e08 ILT |
223 | else if (!is_ordinary && Symbol::is_common_shndx(shndx)) |
224 | bits |= common_flag; | |
70e654ba ILT |
225 | else |
226 | bits |= def_flag; | |
227 | break; | |
228 | } | |
229 | ||
230 | return bits; | |
231 | } | |
232 | ||
14bfc3f5 | 233 | // Resolve a symbol. This is called the second and subsequent times |
d491d34e ILT |
234 | // we see a symbol. TO is the pre-existing symbol. ST_SHNDX is the |
235 | // section index for SYM, possibly adjusted for many sections. | |
236 | // IS_ORDINARY is whether ST_SHNDX is a normal section index rather | |
237 | // than a special code. ORIG_ST_SHNDX is the original section index, | |
238 | // before any munging because of discarded sections, except that all | |
95d14cd3 | 239 | // non-ordinary section indexes are mapped to SHN_UNDEF. VERSION is |
d491d34e | 240 | // the version of SYM. |
14bfc3f5 ILT |
241 | |
242 | template<int size, bool big_endian> | |
243 | void | |
1564db8d | 244 | Symbol_table::resolve(Sized_symbol<size>* to, |
14bfc3f5 | 245 | const elfcpp::Sym<size, big_endian>& sym, |
d491d34e ILT |
246 | unsigned int st_shndx, bool is_ordinary, |
247 | unsigned int orig_st_shndx, | |
14b31740 | 248 | Object* object, const char* version) |
14bfc3f5 | 249 | { |
534b4e5f ILT |
250 | // It's possible for a symbol to be defined in an object file |
251 | // using .symver to give it a version, and for there to also be | |
252 | // a linker script giving that symbol the same version. We | |
253 | // don't want to give a multiple-definition error for this | |
254 | // harmless redefinition. | |
255 | bool to_is_ordinary; | |
256 | if (to->source() == Symbol::FROM_OBJECT | |
257 | && to->object() == object | |
258 | && is_ordinary | |
259 | && to->is_defined() | |
260 | && to->shndx(&to_is_ordinary) == st_shndx | |
261 | && to_is_ordinary | |
262 | && to->value() == sym.get_st_value()) | |
263 | return; | |
264 | ||
029ba973 | 265 | if (parameters->target().has_resolve()) |
14bfc3f5 | 266 | { |
274e99f9 | 267 | Sized_target<size, big_endian>* sized_target; |
029ba973 | 268 | sized_target = parameters->sized_target<size, big_endian>(); |
14b31740 | 269 | sized_target->resolve(to, sym, object, version); |
14bfc3f5 ILT |
270 | return; |
271 | } | |
272 | ||
86f2e683 ILT |
273 | if (!object->is_dynamic()) |
274 | { | |
275 | // Record that we've seen this symbol in a regular object. | |
276 | to->set_in_reg(); | |
277 | } | |
2da73f13 CC |
278 | else if (st_shndx == elfcpp::SHN_UNDEF |
279 | && (to->visibility() == elfcpp::STV_HIDDEN | |
280 | || to->visibility() == elfcpp::STV_INTERNAL)) | |
645afe0c CC |
281 | { |
282 | // A dynamic object cannot reference a hidden or internal symbol | |
283 | // defined in another object. | |
284 | gold_warning(_("%s symbol '%s' in %s is referenced by DSO %s"), | |
285 | (to->visibility() == elfcpp::STV_HIDDEN | |
286 | ? "hidden" | |
287 | : "internal"), | |
288 | to->demangled_name().c_str(), | |
289 | to->object()->name().c_str(), | |
290 | object->name().c_str()); | |
291 | return; | |
292 | } | |
86f2e683 ILT |
293 | else |
294 | { | |
295 | // Record that we've seen this symbol in a dynamic object. | |
296 | to->set_in_dyn(); | |
297 | } | |
14bfc3f5 | 298 | |
89fc3421 CC |
299 | // Record if we've seen this symbol in a real ELF object (i.e., the |
300 | // symbol is referenced from outside the world known to the plugin). | |
f7c5b166 | 301 | if (object->pluginobj() == NULL && !object->is_dynamic()) |
89fc3421 CC |
302 | to->set_in_real_elf(); |
303 | ||
304 | // If we're processing replacement files, allow new symbols to override | |
305 | // the placeholders from the plugin objects. | |
6168c2a1 RÁE |
306 | // Treat common symbols specially since it is possible that an ELF |
307 | // file increased the size of the alignment. | |
89fc3421 CC |
308 | if (to->source() == Symbol::FROM_OBJECT) |
309 | { | |
310 | Pluginobj* obj = to->object()->pluginobj(); | |
311 | if (obj != NULL | |
1707f183 | 312 | && parameters->options().plugins()->in_replacement_phase()) |
89fc3421 | 313 | { |
1707f183 CC |
314 | bool adjust_common = false; |
315 | typename Sized_symbol<size>::Size_type tosize = 0; | |
316 | typename Sized_symbol<size>::Value_type tovalue = 0; | |
317 | if (to->is_common() && !is_ordinary && st_shndx == elfcpp::SHN_COMMON) | |
318 | { | |
319 | adjust_common = true; | |
db4c9594 CC |
320 | tosize = to->symsize(); |
321 | tovalue = to->value(); | |
1707f183 CC |
322 | } |
323 | this->override(to, sym, st_shndx, is_ordinary, object, version); | |
324 | if (adjust_common) | |
325 | { | |
326 | if (tosize > to->symsize()) | |
327 | to->set_symsize(tosize); | |
328 | if (tovalue > to->value()) | |
329 | to->set_value(tovalue); | |
330 | } | |
331 | return; | |
89fc3421 CC |
332 | } |
333 | } | |
334 | ||
ba4d53bf ILT |
335 | // A new weak undefined reference, merging with an old weak |
336 | // reference, could be a One Definition Rule (ODR) violation -- | |
337 | // especially if the types or sizes of the references differ. We'll | |
338 | // store such pairs and look them up later to make sure they | |
339 | // actually refer to the same lines of code. We also check | |
340 | // combinations of weak and strong, which might occur if one case is | |
341 | // inline and the other is not. (Note: not all ODR violations can | |
342 | // be found this way, and not everything this finds is an ODR | |
343 | // violation. But it's helpful to warn about.) | |
ba4d53bf ILT |
344 | if (parameters->options().detect_odr_violations() |
345 | && (sym.get_st_bind() == elfcpp::STB_WEAK | |
346 | || to->binding() == elfcpp::STB_WEAK) | |
347 | && orig_st_shndx != elfcpp::SHN_UNDEF | |
348 | && to->shndx(&to_is_ordinary) != elfcpp::SHN_UNDEF | |
349 | && to_is_ordinary | |
350 | && sym.get_st_size() != 0 // Ignore weird 0-sized symbols. | |
351 | && to->symsize() != 0 | |
352 | && (sym.get_st_type() != to->type() | |
353 | || sym.get_st_size() != to->symsize()) | |
354 | // C does not have a concept of ODR, so we only need to do this | |
355 | // on C++ symbols. These have (mangled) names starting with _Z. | |
356 | && to->name()[0] == '_' && to->name()[1] == 'Z') | |
357 | { | |
358 | Symbol_location fromloc | |
76677ad0 | 359 | = { object, orig_st_shndx, static_cast<off_t>(sym.get_st_value()) }; |
ba4d53bf | 360 | Symbol_location toloc = { to->object(), to->shndx(&to_is_ordinary), |
76677ad0 | 361 | static_cast<off_t>(to->value()) }; |
ba4d53bf ILT |
362 | this->candidate_odr_violations_[to->name()].insert(fromloc); |
363 | this->candidate_odr_violations_[to->name()].insert(toloc); | |
364 | } | |
365 | ||
32364e50 CC |
366 | // Plugins don't provide a symbol type, so adopt the existing type |
367 | // if the FROM symbol is from a plugin. | |
368 | elfcpp::STT fromtype = (object->pluginobj() != NULL | |
369 | ? to->type() | |
370 | : sym.get_st_type()); | |
70e654ba ILT |
371 | unsigned int frombits = symbol_to_bits(sym.get_st_bind(), |
372 | object->is_dynamic(), | |
d491d34e | 373 | st_shndx, is_ordinary, |
32364e50 | 374 | fromtype); |
14bfc3f5 | 375 | |
86f2e683 | 376 | bool adjust_common_sizes; |
ce279a62 | 377 | bool adjust_dyndef; |
1ae4d23b | 378 | typename Sized_symbol<size>::Size_type tosize = to->symsize(); |
32364e50 | 379 | if (Symbol_table::should_override(to, frombits, fromtype, OBJECT, |
62855347 | 380 | object, &adjust_common_sizes, |
ce279a62 | 381 | &adjust_dyndef)) |
86f2e683 | 382 | { |
ce279a62 | 383 | elfcpp::STB tobinding = to->binding(); |
fd325007 | 384 | typename Sized_symbol<size>::Value_type tovalue = to->value(); |
d491d34e | 385 | this->override(to, sym, st_shndx, is_ordinary, object, version); |
fd325007 ILT |
386 | if (adjust_common_sizes) |
387 | { | |
388 | if (tosize > to->symsize()) | |
389 | to->set_symsize(tosize); | |
390 | if (tovalue > to->value()) | |
391 | to->set_value(tovalue); | |
392 | } | |
ce279a62 CC |
393 | if (adjust_dyndef) |
394 | { | |
395 | // We are overriding an UNDEF or WEAK UNDEF with a DYN DEF. | |
396 | // Remember which kind of UNDEF it was for future reference. | |
397 | to->set_undef_binding(tobinding); | |
398 | } | |
86f2e683 ILT |
399 | } |
400 | else | |
401 | { | |
fd325007 ILT |
402 | if (adjust_common_sizes) |
403 | { | |
404 | if (sym.get_st_size() > tosize) | |
405 | to->set_symsize(sym.get_st_size()); | |
406 | if (sym.get_st_value() > to->value()) | |
407 | to->set_value(sym.get_st_value()); | |
408 | } | |
ce279a62 CC |
409 | if (adjust_dyndef) |
410 | { | |
411 | // We are keeping a DYN DEF after seeing an UNDEF or WEAK UNDEF. | |
412 | // Remember which kind of UNDEF it was. | |
413 | to->set_undef_binding(sym.get_st_bind()); | |
414 | } | |
0602e05a ILT |
415 | // The ELF ABI says that even for a reference to a symbol we |
416 | // merge the visibility. | |
417 | to->override_visibility(sym.get_st_visibility()); | |
86f2e683 | 418 | } |
70e654ba | 419 | |
1ae4d23b ILT |
420 | if (adjust_common_sizes && parameters->options().warn_common()) |
421 | { | |
422 | if (tosize > sym.get_st_size()) | |
423 | Symbol_table::report_resolve_problem(false, | |
424 | _("common of '%s' overriding " | |
425 | "smaller common"), | |
99fff23b | 426 | to, OBJECT, object); |
1ae4d23b ILT |
427 | else if (tosize < sym.get_st_size()) |
428 | Symbol_table::report_resolve_problem(false, | |
429 | _("common of '%s' overidden by " | |
430 | "larger common"), | |
99fff23b | 431 | to, OBJECT, object); |
1ae4d23b ILT |
432 | else |
433 | Symbol_table::report_resolve_problem(false, | |
434 | _("multiple common of '%s'"), | |
99fff23b | 435 | to, OBJECT, object); |
1ae4d23b | 436 | } |
86f2e683 ILT |
437 | } |
438 | ||
439 | // Handle the core of symbol resolution. This is called with the | |
440 | // existing symbol, TO, and a bitflag describing the new symbol. This | |
441 | // returns true if we should override the existing symbol with the new | |
442 | // one, and returns false otherwise. It sets *ADJUST_COMMON_SIZES to | |
443 | // true if we should set the symbol size to the maximum of the TO and | |
444 | // FROM sizes. It handles error conditions. | |
445 | ||
446 | bool | |
447 | Symbol_table::should_override(const Symbol* to, unsigned int frombits, | |
62855347 ILT |
448 | elfcpp::STT fromtype, Defined defined, |
449 | Object* object, bool* adjust_common_sizes, | |
ce279a62 | 450 | bool* adjust_dyndef) |
86f2e683 ILT |
451 | { |
452 | *adjust_common_sizes = false; | |
ce279a62 | 453 | *adjust_dyndef = false; |
86f2e683 | 454 | |
e5756efb | 455 | unsigned int tobits; |
f3e9c5c5 ILT |
456 | if (to->source() == Symbol::IS_UNDEFINED) |
457 | tobits = symbol_to_bits(to->binding(), false, elfcpp::SHN_UNDEF, true, | |
458 | to->type()); | |
459 | else if (to->source() != Symbol::FROM_OBJECT) | |
d491d34e | 460 | tobits = symbol_to_bits(to->binding(), false, elfcpp::SHN_ABS, false, |
e5756efb ILT |
461 | to->type()); |
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, | |
469 | is_ordinary, | |
470 | to->type()); | |
471 | } | |
14bfc3f5 | 472 | |
32364e50 CC |
473 | if ((to->type() == elfcpp::STT_TLS) ^ (fromtype == elfcpp::STT_TLS) |
474 | && !to->is_placeholder()) | |
62855347 ILT |
475 | Symbol_table::report_resolve_problem(true, |
476 | _("symbol '%s' used as both __thread " | |
477 | "and non-__thread"), | |
478 | to, defined, object); | |
1564db8d | 479 | |
14bfc3f5 ILT |
480 | // We use a giant switch table for symbol resolution. This code is |
481 | // unwieldy, but: 1) it is efficient; 2) we definitely handle all | |
482 | // cases; 3) it is easy to change the handling of a particular case. | |
483 | // The alternative would be a series of conditionals, but it is easy | |
484 | // to get the ordering wrong. This could also be done as a table, | |
485 | // but that is no easier to understand than this large switch | |
486 | // statement. | |
487 | ||
86f2e683 ILT |
488 | // These are the values generated by the bit codes. |
489 | enum | |
490 | { | |
491 | DEF = global_flag | regular_flag | def_flag, | |
492 | WEAK_DEF = weak_flag | regular_flag | def_flag, | |
493 | DYN_DEF = global_flag | dynamic_flag | def_flag, | |
494 | DYN_WEAK_DEF = weak_flag | dynamic_flag | def_flag, | |
495 | UNDEF = global_flag | regular_flag | undef_flag, | |
496 | WEAK_UNDEF = weak_flag | regular_flag | undef_flag, | |
497 | DYN_UNDEF = global_flag | dynamic_flag | undef_flag, | |
498 | DYN_WEAK_UNDEF = weak_flag | dynamic_flag | undef_flag, | |
499 | COMMON = global_flag | regular_flag | common_flag, | |
500 | WEAK_COMMON = weak_flag | regular_flag | common_flag, | |
501 | DYN_COMMON = global_flag | dynamic_flag | common_flag, | |
502 | DYN_WEAK_COMMON = weak_flag | dynamic_flag | common_flag | |
503 | }; | |
504 | ||
14bfc3f5 ILT |
505 | switch (tobits * 16 + frombits) |
506 | { | |
507 | case DEF * 16 + DEF: | |
12e14209 | 508 | // Two definitions of the same symbol. |
878405a8 ILT |
509 | |
510 | // If either symbol is defined by an object included using | |
511 | // --just-symbols, then don't warn. This is for compatibility | |
512 | // with the GNU linker. FIXME: This is a hack. | |
513 | if ((to->source() == Symbol::FROM_OBJECT && to->object()->just_symbols()) | |
99fff23b | 514 | || (object != NULL && object->just_symbols())) |
878405a8 ILT |
515 | return false; |
516 | ||
9c4ae156 | 517 | if (!parameters->options().muldefs()) |
30bc8c46 ILT |
518 | Symbol_table::report_resolve_problem(true, |
519 | _("multiple definition of '%s'"), | |
520 | to, defined, object); | |
86f2e683 | 521 | return false; |
14bfc3f5 ILT |
522 | |
523 | case WEAK_DEF * 16 + DEF: | |
1564db8d ILT |
524 | // We've seen a weak definition, and now we see a strong |
525 | // definition. In the original SVR4 linker, this was treated as | |
526 | // a multiple definition error. In the Solaris linker and the | |
527 | // GNU linker, a weak definition followed by a regular | |
528 | // definition causes the weak definition to be overridden. We | |
529 | // are currently compatible with the GNU linker. In the future | |
530 | // we should add a target specific option to change this. | |
531 | // FIXME. | |
86f2e683 | 532 | return true; |
14bfc3f5 ILT |
533 | |
534 | case DYN_DEF * 16 + DEF: | |
535 | case DYN_WEAK_DEF * 16 + DEF: | |
1564db8d ILT |
536 | // We've seen a definition in a dynamic object, and now we see a |
537 | // definition in a regular object. The definition in the | |
538 | // regular object overrides the definition in the dynamic | |
539 | // object. | |
86f2e683 | 540 | return true; |
1564db8d | 541 | |
14bfc3f5 ILT |
542 | case UNDEF * 16 + DEF: |
543 | case WEAK_UNDEF * 16 + DEF: | |
544 | case DYN_UNDEF * 16 + DEF: | |
545 | case DYN_WEAK_UNDEF * 16 + DEF: | |
1564db8d ILT |
546 | // We've seen an undefined reference, and now we see a |
547 | // definition. We use the definition. | |
86f2e683 | 548 | return true; |
1564db8d | 549 | |
14bfc3f5 ILT |
550 | case COMMON * 16 + DEF: |
551 | case WEAK_COMMON * 16 + DEF: | |
552 | case DYN_COMMON * 16 + DEF: | |
553 | case DYN_WEAK_COMMON * 16 + DEF: | |
1564db8d | 554 | // We've seen a common symbol and now we see a definition. The |
1ae4d23b ILT |
555 | // definition overrides. |
556 | if (parameters->options().warn_common()) | |
557 | Symbol_table::report_resolve_problem(false, | |
558 | _("definition of '%s' overriding " | |
559 | "common"), | |
99fff23b | 560 | to, defined, object); |
86f2e683 | 561 | return true; |
14bfc3f5 ILT |
562 | |
563 | case DEF * 16 + WEAK_DEF: | |
564 | case WEAK_DEF * 16 + WEAK_DEF: | |
1564db8d ILT |
565 | // We've seen a definition and now we see a weak definition. We |
566 | // ignore the new weak definition. | |
86f2e683 | 567 | return false; |
1564db8d | 568 | |
14bfc3f5 ILT |
569 | case DYN_DEF * 16 + WEAK_DEF: |
570 | case DYN_WEAK_DEF * 16 + WEAK_DEF: | |
1564db8d ILT |
571 | // We've seen a dynamic definition and now we see a regular weak |
572 | // definition. The regular weak definition overrides. | |
86f2e683 | 573 | return true; |
1564db8d | 574 | |
14bfc3f5 ILT |
575 | case UNDEF * 16 + WEAK_DEF: |
576 | case WEAK_UNDEF * 16 + WEAK_DEF: | |
577 | case DYN_UNDEF * 16 + WEAK_DEF: | |
578 | case DYN_WEAK_UNDEF * 16 + WEAK_DEF: | |
1564db8d | 579 | // A weak definition of a currently undefined symbol. |
86f2e683 | 580 | return true; |
1564db8d | 581 | |
14bfc3f5 ILT |
582 | case COMMON * 16 + WEAK_DEF: |
583 | case WEAK_COMMON * 16 + WEAK_DEF: | |
1564db8d | 584 | // A weak definition does not override a common definition. |
86f2e683 | 585 | return false; |
1564db8d | 586 | |
14bfc3f5 ILT |
587 | case DYN_COMMON * 16 + WEAK_DEF: |
588 | case DYN_WEAK_COMMON * 16 + WEAK_DEF: | |
1564db8d | 589 | // A weak definition does override a definition in a dynamic |
1ae4d23b ILT |
590 | // object. |
591 | if (parameters->options().warn_common()) | |
592 | Symbol_table::report_resolve_problem(false, | |
593 | _("definition of '%s' overriding " | |
594 | "dynamic common definition"), | |
99fff23b | 595 | to, defined, object); |
86f2e683 | 596 | return true; |
14bfc3f5 ILT |
597 | |
598 | case DEF * 16 + DYN_DEF: | |
599 | case WEAK_DEF * 16 + DYN_DEF: | |
600 | case DYN_DEF * 16 + DYN_DEF: | |
601 | case DYN_WEAK_DEF * 16 + DYN_DEF: | |
1564db8d | 602 | // Ignore a dynamic definition if we already have a definition. |
86f2e683 | 603 | return false; |
1564db8d | 604 | |
14bfc3f5 | 605 | case UNDEF * 16 + DYN_DEF: |
14bfc3f5 ILT |
606 | case DYN_UNDEF * 16 + DYN_DEF: |
607 | case DYN_WEAK_UNDEF * 16 + DYN_DEF: | |
1564db8d | 608 | // Use a dynamic definition if we have a reference. |
86f2e683 | 609 | return true; |
1564db8d | 610 | |
ce279a62 CC |
611 | case WEAK_UNDEF * 16 + DYN_DEF: |
612 | // When overriding a weak undef by a dynamic definition, | |
613 | // we need to remember that the original undef was weak. | |
614 | *adjust_dyndef = true; | |
615 | return true; | |
616 | ||
14bfc3f5 ILT |
617 | case COMMON * 16 + DYN_DEF: |
618 | case WEAK_COMMON * 16 + DYN_DEF: | |
619 | case DYN_COMMON * 16 + DYN_DEF: | |
620 | case DYN_WEAK_COMMON * 16 + DYN_DEF: | |
1564db8d ILT |
621 | // Ignore a dynamic definition if we already have a common |
622 | // definition. | |
86f2e683 | 623 | return false; |
14bfc3f5 ILT |
624 | |
625 | case DEF * 16 + DYN_WEAK_DEF: | |
626 | case WEAK_DEF * 16 + DYN_WEAK_DEF: | |
627 | case DYN_DEF * 16 + DYN_WEAK_DEF: | |
628 | case DYN_WEAK_DEF * 16 + DYN_WEAK_DEF: | |
1564db8d ILT |
629 | // Ignore a weak dynamic definition if we already have a |
630 | // definition. | |
86f2e683 | 631 | return false; |
1564db8d | 632 | |
14bfc3f5 | 633 | case UNDEF * 16 + DYN_WEAK_DEF: |
74f67560 DK |
634 | // When overriding an undef by a dynamic weak definition, |
635 | // we need to remember that the original undef was not weak. | |
636 | *adjust_dyndef = true; | |
637 | return true; | |
638 | ||
14bfc3f5 ILT |
639 | case DYN_UNDEF * 16 + DYN_WEAK_DEF: |
640 | case DYN_WEAK_UNDEF * 16 + DYN_WEAK_DEF: | |
1564db8d | 641 | // Use a weak dynamic definition if we have a reference. |
86f2e683 | 642 | return true; |
1564db8d | 643 | |
ce279a62 CC |
644 | case WEAK_UNDEF * 16 + DYN_WEAK_DEF: |
645 | // When overriding a weak undef by a dynamic definition, | |
646 | // we need to remember that the original undef was weak. | |
647 | *adjust_dyndef = true; | |
648 | return true; | |
649 | ||
14bfc3f5 ILT |
650 | case COMMON * 16 + DYN_WEAK_DEF: |
651 | case WEAK_COMMON * 16 + DYN_WEAK_DEF: | |
652 | case DYN_COMMON * 16 + DYN_WEAK_DEF: | |
653 | case DYN_WEAK_COMMON * 16 + DYN_WEAK_DEF: | |
1564db8d ILT |
654 | // Ignore a weak dynamic definition if we already have a common |
655 | // definition. | |
86f2e683 | 656 | return false; |
14bfc3f5 ILT |
657 | |
658 | case DEF * 16 + UNDEF: | |
659 | case WEAK_DEF * 16 + UNDEF: | |
14bfc3f5 | 660 | case UNDEF * 16 + UNDEF: |
ead1e424 | 661 | // A new undefined reference tells us nothing. |
86f2e683 | 662 | return false; |
ead1e424 | 663 | |
ce279a62 CC |
664 | case DYN_DEF * 16 + UNDEF: |
665 | case DYN_WEAK_DEF * 16 + UNDEF: | |
666 | // For a dynamic def, we need to remember which kind of undef we see. | |
667 | *adjust_dyndef = true; | |
668 | return false; | |
669 | ||
14bfc3f5 ILT |
670 | case WEAK_UNDEF * 16 + UNDEF: |
671 | case DYN_UNDEF * 16 + UNDEF: | |
672 | case DYN_WEAK_UNDEF * 16 + UNDEF: | |
ead1e424 | 673 | // A strong undef overrides a dynamic or weak undef. |
86f2e683 | 674 | return true; |
ead1e424 | 675 | |
14bfc3f5 ILT |
676 | case COMMON * 16 + UNDEF: |
677 | case WEAK_COMMON * 16 + UNDEF: | |
678 | case DYN_COMMON * 16 + UNDEF: | |
679 | case DYN_WEAK_COMMON * 16 + UNDEF: | |
1564db8d | 680 | // A new undefined reference tells us nothing. |
86f2e683 | 681 | return false; |
14bfc3f5 ILT |
682 | |
683 | case DEF * 16 + WEAK_UNDEF: | |
684 | case WEAK_DEF * 16 + WEAK_UNDEF: | |
14bfc3f5 ILT |
685 | case UNDEF * 16 + WEAK_UNDEF: |
686 | case WEAK_UNDEF * 16 + WEAK_UNDEF: | |
687 | case DYN_UNDEF * 16 + WEAK_UNDEF: | |
14bfc3f5 ILT |
688 | case COMMON * 16 + WEAK_UNDEF: |
689 | case WEAK_COMMON * 16 + WEAK_UNDEF: | |
690 | case DYN_COMMON * 16 + WEAK_UNDEF: | |
691 | case DYN_WEAK_COMMON * 16 + WEAK_UNDEF: | |
a4649286 DK |
692 | // A new weak undefined reference tells us nothing unless the |
693 | // exisiting symbol is a dynamic weak reference. | |
86f2e683 | 694 | return false; |
14bfc3f5 | 695 | |
a4649286 DK |
696 | case DYN_WEAK_UNDEF * 16 + WEAK_UNDEF: |
697 | // A new weak reference overrides an existing dynamic weak reference. | |
698 | // This is necessary because a dynamic weak reference remembers | |
699 | // the old binding, which may not be weak. If we keeps the existing | |
700 | // dynamic weak reference, the weakness may be dropped in the output. | |
701 | return true; | |
702 | ||
ce279a62 CC |
703 | case DYN_DEF * 16 + WEAK_UNDEF: |
704 | case DYN_WEAK_DEF * 16 + WEAK_UNDEF: | |
705 | // For a dynamic def, we need to remember which kind of undef we see. | |
706 | *adjust_dyndef = true; | |
707 | return false; | |
708 | ||
14bfc3f5 ILT |
709 | case DEF * 16 + DYN_UNDEF: |
710 | case WEAK_DEF * 16 + DYN_UNDEF: | |
711 | case DYN_DEF * 16 + DYN_UNDEF: | |
712 | case DYN_WEAK_DEF * 16 + DYN_UNDEF: | |
713 | case UNDEF * 16 + DYN_UNDEF: | |
714 | case WEAK_UNDEF * 16 + DYN_UNDEF: | |
715 | case DYN_UNDEF * 16 + DYN_UNDEF: | |
716 | case DYN_WEAK_UNDEF * 16 + DYN_UNDEF: | |
717 | case COMMON * 16 + DYN_UNDEF: | |
718 | case WEAK_COMMON * 16 + DYN_UNDEF: | |
719 | case DYN_COMMON * 16 + DYN_UNDEF: | |
720 | case DYN_WEAK_COMMON * 16 + DYN_UNDEF: | |
1564db8d | 721 | // A new dynamic undefined reference tells us nothing. |
86f2e683 | 722 | return false; |
14bfc3f5 ILT |
723 | |
724 | case DEF * 16 + DYN_WEAK_UNDEF: | |
725 | case WEAK_DEF * 16 + DYN_WEAK_UNDEF: | |
726 | case DYN_DEF * 16 + DYN_WEAK_UNDEF: | |
727 | case DYN_WEAK_DEF * 16 + DYN_WEAK_UNDEF: | |
728 | case UNDEF * 16 + DYN_WEAK_UNDEF: | |
729 | case WEAK_UNDEF * 16 + DYN_WEAK_UNDEF: | |
730 | case DYN_UNDEF * 16 + DYN_WEAK_UNDEF: | |
731 | case DYN_WEAK_UNDEF * 16 + DYN_WEAK_UNDEF: | |
732 | case COMMON * 16 + DYN_WEAK_UNDEF: | |
733 | case WEAK_COMMON * 16 + DYN_WEAK_UNDEF: | |
734 | case DYN_COMMON * 16 + DYN_WEAK_UNDEF: | |
735 | case DYN_WEAK_COMMON * 16 + DYN_WEAK_UNDEF: | |
1564db8d | 736 | // A new weak dynamic undefined reference tells us nothing. |
86f2e683 | 737 | return false; |
14bfc3f5 ILT |
738 | |
739 | case DEF * 16 + COMMON: | |
1564db8d | 740 | // A common symbol does not override a definition. |
1ae4d23b ILT |
741 | if (parameters->options().warn_common()) |
742 | Symbol_table::report_resolve_problem(false, | |
743 | _("common '%s' overridden by " | |
744 | "previous definition"), | |
99fff23b | 745 | to, defined, object); |
86f2e683 | 746 | return false; |
1564db8d | 747 | |
14bfc3f5 ILT |
748 | case WEAK_DEF * 16 + COMMON: |
749 | case DYN_DEF * 16 + COMMON: | |
750 | case DYN_WEAK_DEF * 16 + COMMON: | |
1564db8d ILT |
751 | // A common symbol does override a weak definition or a dynamic |
752 | // definition. | |
86f2e683 | 753 | return true; |
1564db8d | 754 | |
14bfc3f5 ILT |
755 | case UNDEF * 16 + COMMON: |
756 | case WEAK_UNDEF * 16 + COMMON: | |
757 | case DYN_UNDEF * 16 + COMMON: | |
758 | case DYN_WEAK_UNDEF * 16 + COMMON: | |
1564db8d | 759 | // A common symbol is a definition for a reference. |
86f2e683 | 760 | return true; |
1564db8d | 761 | |
14bfc3f5 | 762 | case COMMON * 16 + COMMON: |
ead1e424 | 763 | // Set the size to the maximum. |
86f2e683 ILT |
764 | *adjust_common_sizes = true; |
765 | return false; | |
ead1e424 | 766 | |
14bfc3f5 | 767 | case WEAK_COMMON * 16 + COMMON: |
ead1e424 ILT |
768 | // I'm not sure just what a weak common symbol means, but |
769 | // presumably it can be overridden by a regular common symbol. | |
86f2e683 | 770 | return true; |
ead1e424 | 771 | |
14bfc3f5 ILT |
772 | case DYN_COMMON * 16 + COMMON: |
773 | case DYN_WEAK_COMMON * 16 + COMMON: | |
86f2e683 ILT |
774 | // Use the real common symbol, but adjust the size if necessary. |
775 | *adjust_common_sizes = true; | |
776 | return true; | |
14bfc3f5 ILT |
777 | |
778 | case DEF * 16 + WEAK_COMMON: | |
779 | case WEAK_DEF * 16 + WEAK_COMMON: | |
780 | case DYN_DEF * 16 + WEAK_COMMON: | |
781 | case DYN_WEAK_DEF * 16 + WEAK_COMMON: | |
ead1e424 ILT |
782 | // Whatever a weak common symbol is, it won't override a |
783 | // definition. | |
86f2e683 | 784 | return false; |
ead1e424 | 785 | |
14bfc3f5 ILT |
786 | case UNDEF * 16 + WEAK_COMMON: |
787 | case WEAK_UNDEF * 16 + WEAK_COMMON: | |
788 | case DYN_UNDEF * 16 + WEAK_COMMON: | |
789 | case DYN_WEAK_UNDEF * 16 + WEAK_COMMON: | |
ead1e424 | 790 | // A weak common symbol is better than an undefined symbol. |
86f2e683 | 791 | return true; |
ead1e424 | 792 | |
14bfc3f5 ILT |
793 | case COMMON * 16 + WEAK_COMMON: |
794 | case WEAK_COMMON * 16 + WEAK_COMMON: | |
795 | case DYN_COMMON * 16 + WEAK_COMMON: | |
796 | case DYN_WEAK_COMMON * 16 + WEAK_COMMON: | |
ead1e424 ILT |
797 | // Ignore a weak common symbol in the presence of a real common |
798 | // symbol. | |
86f2e683 | 799 | return false; |
14bfc3f5 ILT |
800 | |
801 | case DEF * 16 + DYN_COMMON: | |
802 | case WEAK_DEF * 16 + DYN_COMMON: | |
803 | case DYN_DEF * 16 + DYN_COMMON: | |
804 | case DYN_WEAK_DEF * 16 + DYN_COMMON: | |
ead1e424 ILT |
805 | // Ignore a dynamic common symbol in the presence of a |
806 | // definition. | |
86f2e683 | 807 | return false; |
ead1e424 | 808 | |
14bfc3f5 ILT |
809 | case UNDEF * 16 + DYN_COMMON: |
810 | case WEAK_UNDEF * 16 + DYN_COMMON: | |
811 | case DYN_UNDEF * 16 + DYN_COMMON: | |
812 | case DYN_WEAK_UNDEF * 16 + DYN_COMMON: | |
ead1e424 | 813 | // A dynamic common symbol is a definition of sorts. |
86f2e683 | 814 | return true; |
ead1e424 | 815 | |
14bfc3f5 ILT |
816 | case COMMON * 16 + DYN_COMMON: |
817 | case WEAK_COMMON * 16 + DYN_COMMON: | |
818 | case DYN_COMMON * 16 + DYN_COMMON: | |
819 | case DYN_WEAK_COMMON * 16 + DYN_COMMON: | |
ead1e424 | 820 | // Set the size to the maximum. |
86f2e683 ILT |
821 | *adjust_common_sizes = true; |
822 | return false; | |
14bfc3f5 ILT |
823 | |
824 | case DEF * 16 + DYN_WEAK_COMMON: | |
825 | case WEAK_DEF * 16 + DYN_WEAK_COMMON: | |
826 | case DYN_DEF * 16 + DYN_WEAK_COMMON: | |
827 | case DYN_WEAK_DEF * 16 + DYN_WEAK_COMMON: | |
ead1e424 | 828 | // A common symbol is ignored in the face of a definition. |
86f2e683 | 829 | return false; |
ead1e424 | 830 | |
14bfc3f5 ILT |
831 | case UNDEF * 16 + DYN_WEAK_COMMON: |
832 | case WEAK_UNDEF * 16 + DYN_WEAK_COMMON: | |
833 | case DYN_UNDEF * 16 + DYN_WEAK_COMMON: | |
834 | case DYN_WEAK_UNDEF * 16 + DYN_WEAK_COMMON: | |
ead1e424 | 835 | // I guess a weak common symbol is better than a definition. |
86f2e683 | 836 | return true; |
ead1e424 | 837 | |
14bfc3f5 ILT |
838 | case COMMON * 16 + DYN_WEAK_COMMON: |
839 | case WEAK_COMMON * 16 + DYN_WEAK_COMMON: | |
840 | case DYN_COMMON * 16 + DYN_WEAK_COMMON: | |
841 | case DYN_WEAK_COMMON * 16 + DYN_WEAK_COMMON: | |
ead1e424 | 842 | // Set the size to the maximum. |
86f2e683 ILT |
843 | *adjust_common_sizes = true; |
844 | return false; | |
1564db8d ILT |
845 | |
846 | default: | |
a3ad94ed | 847 | gold_unreachable(); |
14bfc3f5 ILT |
848 | } |
849 | } | |
850 | ||
1ae4d23b ILT |
851 | // Issue an error or warning due to symbol resolution. IS_ERROR |
852 | // indicates an error rather than a warning. MSG is the error | |
853 | // message; it is expected to have a %s for the symbol name. TO is | |
99fff23b ILT |
854 | // the existing symbol. DEFINED/OBJECT is where the new symbol was |
855 | // found. | |
1ae4d23b ILT |
856 | |
857 | // FIXME: We should have better location information here. When the | |
858 | // symbol is defined, we should be able to pull the location from the | |
859 | // debug info if there is any. | |
860 | ||
861 | void | |
862 | Symbol_table::report_resolve_problem(bool is_error, const char* msg, | |
99fff23b ILT |
863 | const Symbol* to, Defined defined, |
864 | Object* object) | |
1ae4d23b ILT |
865 | { |
866 | std::string demangled(to->demangled_name()); | |
867 | size_t len = strlen(msg) + demangled.length() + 10; | |
868 | char* buf = new char[len]; | |
869 | snprintf(buf, len, msg, demangled.c_str()); | |
870 | ||
871 | const char* objname; | |
99fff23b ILT |
872 | switch (defined) |
873 | { | |
874 | case OBJECT: | |
875 | objname = object->name().c_str(); | |
876 | break; | |
877 | case COPY: | |
878 | objname = _("COPY reloc"); | |
879 | break; | |
880 | case DEFSYM: | |
881 | case UNDEFINED: | |
882 | objname = _("command line"); | |
883 | break; | |
884 | case SCRIPT: | |
885 | objname = _("linker script"); | |
886 | break; | |
887 | case PREDEFINED: | |
5146f448 | 888 | case INCREMENTAL_BASE: |
99fff23b ILT |
889 | objname = _("linker defined"); |
890 | break; | |
891 | default: | |
892 | gold_unreachable(); | |
893 | } | |
1ae4d23b ILT |
894 | |
895 | if (is_error) | |
896 | gold_error("%s: %s", objname, buf); | |
897 | else | |
898 | gold_warning("%s: %s", objname, buf); | |
899 | ||
900 | delete[] buf; | |
901 | ||
902 | if (to->source() == Symbol::FROM_OBJECT) | |
903 | objname = to->object()->name().c_str(); | |
904 | else | |
905 | objname = _("command line"); | |
906 | gold_info("%s: %s: previous definition here", program_name, objname); | |
907 | } | |
908 | ||
86f2e683 ILT |
909 | // A special case of should_override which is only called for a strong |
910 | // defined symbol from a regular object file. This is used when | |
911 | // defining special symbols. | |
912 | ||
913 | bool | |
62855347 ILT |
914 | Symbol_table::should_override_with_special(const Symbol* to, |
915 | elfcpp::STT fromtype, | |
916 | Defined defined) | |
86f2e683 ILT |
917 | { |
918 | bool adjust_common_sizes; | |
ce279a62 | 919 | bool adjust_dyn_def; |
86f2e683 | 920 | unsigned int frombits = global_flag | regular_flag | def_flag; |
62855347 ILT |
921 | bool ret = Symbol_table::should_override(to, frombits, fromtype, defined, |
922 | NULL, &adjust_common_sizes, | |
ce279a62 CC |
923 | &adjust_dyn_def); |
924 | gold_assert(!adjust_common_sizes && !adjust_dyn_def); | |
86f2e683 ILT |
925 | return ret; |
926 | } | |
927 | ||
928 | // Override symbol base with a special symbol. | |
929 | ||
930 | void | |
931 | Symbol::override_base_with_special(const Symbol* from) | |
932 | { | |
21131061 ILT |
933 | bool same_name = this->name_ == from->name_; |
934 | gold_assert(same_name || this->has_alias()); | |
46fe1623 | 935 | |
d1bddd3c CC |
936 | // If we are overriding an undef, remember the original binding. |
937 | if (this->is_undefined()) | |
938 | this->set_undef_binding(this->binding_); | |
939 | ||
86f2e683 ILT |
940 | this->source_ = from->source_; |
941 | switch (from->source_) | |
942 | { | |
943 | case FROM_OBJECT: | |
944 | this->u_.from_object = from->u_.from_object; | |
945 | break; | |
946 | case IN_OUTPUT_DATA: | |
947 | this->u_.in_output_data = from->u_.in_output_data; | |
948 | break; | |
949 | case IN_OUTPUT_SEGMENT: | |
950 | this->u_.in_output_segment = from->u_.in_output_segment; | |
951 | break; | |
f3e9c5c5 ILT |
952 | case IS_CONSTANT: |
953 | case IS_UNDEFINED: | |
86f2e683 ILT |
954 | break; |
955 | default: | |
956 | gold_unreachable(); | |
957 | break; | |
958 | } | |
959 | ||
21131061 | 960 | if (same_name) |
24d47b34 ILT |
961 | { |
962 | // When overriding a versioned symbol with a special symbol, we | |
963 | // may be changing the version. This will happen if we see a | |
964 | // special symbol such as "_end" defined in a shared object with | |
965 | // one version (from a version script), but we want to define it | |
966 | // here with a different version (from a different version | |
967 | // script). | |
968 | this->version_ = from->version_; | |
969 | } | |
86f2e683 ILT |
970 | this->type_ = from->type_; |
971 | this->binding_ = from->binding_; | |
0602e05a | 972 | this->override_visibility(from->visibility_); |
86f2e683 ILT |
973 | this->nonvis_ = from->nonvis_; |
974 | ||
975 | // Special symbols are always considered to be regular symbols. | |
976 | this->in_reg_ = true; | |
46fe1623 ILT |
977 | |
978 | if (from->needs_dynsym_entry_) | |
979 | this->needs_dynsym_entry_ = true; | |
980 | if (from->needs_dynsym_value_) | |
981 | this->needs_dynsym_value_ = true; | |
982 | ||
5146f448 CC |
983 | this->is_predefined_ = from->is_predefined_; |
984 | ||
46fe1623 ILT |
985 | // We shouldn't see these flags. If we do, we need to handle them |
986 | // somehow. | |
46fe1623 | 987 | gold_assert(!from->is_forwarder_); |
880cd20d | 988 | gold_assert(!from->has_plt_offset()); |
46fe1623 ILT |
989 | gold_assert(!from->has_warning_); |
990 | gold_assert(!from->is_copied_from_dynobj_); | |
55a93433 | 991 | gold_assert(!from->is_forced_local_); |
86f2e683 ILT |
992 | } |
993 | ||
994 | // Override a symbol with a special symbol. | |
995 | ||
996 | template<int size> | |
997 | void | |
998 | Sized_symbol<size>::override_with_special(const Sized_symbol<size>* from) | |
999 | { | |
1000 | this->override_base_with_special(from); | |
1001 | this->value_ = from->value_; | |
1002 | this->symsize_ = from->symsize_; | |
1003 | } | |
1004 | ||
aeddab66 ILT |
1005 | // Override TOSYM with the special symbol FROMSYM. This handles all |
1006 | // aliases of TOSYM. | |
1007 | ||
1008 | template<int size> | |
1009 | void | |
1010 | Symbol_table::override_with_special(Sized_symbol<size>* tosym, | |
1011 | const Sized_symbol<size>* fromsym) | |
1012 | { | |
1013 | tosym->override_with_special(fromsym); | |
1014 | if (tosym->has_alias()) | |
1015 | { | |
1016 | Symbol* sym = this->weak_aliases_[tosym]; | |
1017 | gold_assert(sym != NULL); | |
7d1a9ebb | 1018 | Sized_symbol<size>* ssym = this->get_sized_symbol<size>(sym); |
aeddab66 ILT |
1019 | do |
1020 | { | |
1021 | ssym->override_with_special(fromsym); | |
1022 | sym = this->weak_aliases_[ssym]; | |
1023 | gold_assert(sym != NULL); | |
7d1a9ebb | 1024 | ssym = this->get_sized_symbol<size>(sym); |
aeddab66 ILT |
1025 | } |
1026 | while (ssym != tosym); | |
1027 | } | |
0602e05a ILT |
1028 | if (tosym->binding() == elfcpp::STB_LOCAL |
1029 | || ((tosym->visibility() == elfcpp::STV_HIDDEN | |
1030 | || tosym->visibility() == elfcpp::STV_INTERNAL) | |
1031 | && (tosym->binding() == elfcpp::STB_GLOBAL | |
adcf2816 | 1032 | || tosym->binding() == elfcpp::STB_GNU_UNIQUE |
0602e05a ILT |
1033 | || tosym->binding() == elfcpp::STB_WEAK) |
1034 | && !parameters->options().relocatable())) | |
55a93433 | 1035 | this->force_local(tosym); |
aeddab66 ILT |
1036 | } |
1037 | ||
14bfc3f5 ILT |
1038 | // Instantiate the templates we need. We could use the configure |
1039 | // script to restrict this to only the ones needed for implemented | |
1040 | // targets. | |
1041 | ||
6cfaf60b DK |
1042 | // We have to instantiate both big and little endian versions because |
1043 | // these are used by other templates that depends on size only. | |
1044 | ||
1045 | #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG) | |
14bfc3f5 ILT |
1046 | template |
1047 | void | |
193a53d9 | 1048 | Symbol_table::resolve<32, false>( |
1564db8d | 1049 | Sized_symbol<32>* to, |
193a53d9 | 1050 | const elfcpp::Sym<32, false>& sym, |
d491d34e ILT |
1051 | unsigned int st_shndx, |
1052 | bool is_ordinary, | |
1053 | unsigned int orig_st_shndx, | |
14b31740 ILT |
1054 | Object* object, |
1055 | const char* version); | |
14bfc3f5 ILT |
1056 | |
1057 | template | |
1058 | void | |
193a53d9 | 1059 | Symbol_table::resolve<32, true>( |
1564db8d | 1060 | Sized_symbol<32>* to, |
193a53d9 | 1061 | const elfcpp::Sym<32, true>& sym, |
d491d34e ILT |
1062 | unsigned int st_shndx, |
1063 | bool is_ordinary, | |
1064 | unsigned int orig_st_shndx, | |
14b31740 ILT |
1065 | Object* object, |
1066 | const char* version); | |
193a53d9 | 1067 | #endif |
14bfc3f5 | 1068 | |
6cfaf60b | 1069 | #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG) |
14bfc3f5 ILT |
1070 | template |
1071 | void | |
193a53d9 | 1072 | Symbol_table::resolve<64, false>( |
1564db8d | 1073 | Sized_symbol<64>* to, |
193a53d9 | 1074 | const elfcpp::Sym<64, false>& sym, |
d491d34e ILT |
1075 | unsigned int st_shndx, |
1076 | bool is_ordinary, | |
1077 | unsigned int orig_st_shndx, | |
14b31740 ILT |
1078 | Object* object, |
1079 | const char* version); | |
14bfc3f5 ILT |
1080 | |
1081 | template | |
1082 | void | |
193a53d9 | 1083 | Symbol_table::resolve<64, true>( |
1564db8d | 1084 | Sized_symbol<64>* to, |
193a53d9 | 1085 | const elfcpp::Sym<64, true>& sym, |
d491d34e ILT |
1086 | unsigned int st_shndx, |
1087 | bool is_ordinary, | |
1088 | unsigned int orig_st_shndx, | |
14b31740 ILT |
1089 | Object* object, |
1090 | const char* version); | |
193a53d9 | 1091 | #endif |
14bfc3f5 | 1092 | |
86f2e683 ILT |
1093 | #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG) |
1094 | template | |
1095 | void | |
aeddab66 ILT |
1096 | Symbol_table::override_with_special<32>(Sized_symbol<32>*, |
1097 | const Sized_symbol<32>*); | |
86f2e683 ILT |
1098 | #endif |
1099 | ||
1100 | #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG) | |
1101 | template | |
1102 | void | |
aeddab66 ILT |
1103 | Symbol_table::override_with_special<64>(Sized_symbol<64>*, |
1104 | const Sized_symbol<64>*); | |
86f2e683 ILT |
1105 | #endif |
1106 | ||
14bfc3f5 | 1107 | } // End namespace gold. |