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14bfc3f5 ILT |
1 | // resolve.cc -- symbol resolution for gold |
2 | ||
e5756efb | 3 | // Copyright 2006, 2007, 2008 Free Software Foundation, Inc. |
6cb15b7f ILT |
4 | // Written by Ian Lance Taylor <iant@google.com>. |
5 | ||
6 | // This file is part of gold. | |
7 | ||
8 | // This program is free software; you can redistribute it and/or modify | |
9 | // it under the terms of the GNU General Public License as published by | |
10 | // the Free Software Foundation; either version 3 of the License, or | |
11 | // (at your option) any later version. | |
12 | ||
13 | // This program is distributed in the hope that it will be useful, | |
14 | // but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | // GNU General Public License for more details. | |
17 | ||
18 | // You should have received a copy of the GNU General Public License | |
19 | // along with this program; if not, write to the Free Software | |
20 | // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, | |
21 | // MA 02110-1301, USA. | |
22 | ||
14bfc3f5 ILT |
23 | #include "gold.h" |
24 | ||
25 | #include "elfcpp.h" | |
26 | #include "target.h" | |
27 | #include "object.h" | |
28 | #include "symtab.h" | |
29 | ||
30 | namespace gold | |
31 | { | |
32 | ||
1564db8d ILT |
33 | // Symbol methods used in this file. |
34 | ||
35 | // Override the fields in Symbol. | |
36 | ||
37 | template<int size, bool big_endian> | |
38 | void | |
39 | Symbol::override_base(const elfcpp::Sym<size, big_endian>& sym, | |
d491d34e | 40 | unsigned int st_shndx, bool is_ordinary, |
14b31740 | 41 | Object* object, const char* version) |
1564db8d | 42 | { |
a3ad94ed | 43 | gold_assert(this->source_ == FROM_OBJECT); |
ead1e424 | 44 | this->u_.from_object.object = object; |
14b31740 ILT |
45 | if (version != NULL && this->version() != version) |
46 | { | |
47 | gold_assert(this->version() == NULL); | |
48 | this->version_ = version; | |
49 | } | |
d491d34e ILT |
50 | this->u_.from_object.shndx = st_shndx; |
51 | this->is_ordinary_shndx_ = is_ordinary; | |
1564db8d ILT |
52 | this->type_ = sym.get_st_type(); |
53 | this->binding_ = sym.get_st_bind(); | |
54 | this->visibility_ = sym.get_st_visibility(); | |
ead1e424 | 55 | this->nonvis_ = sym.get_st_nonvis(); |
0d4f1889 ILT |
56 | if (object->is_dynamic()) |
57 | this->in_dyn_ = true; | |
58 | else | |
59 | this->in_reg_ = true; | |
1564db8d ILT |
60 | } |
61 | ||
62 | // Override the fields in Sized_symbol. | |
63 | ||
64 | template<int size> | |
65 | template<bool big_endian> | |
66 | void | |
67 | Sized_symbol<size>::override(const elfcpp::Sym<size, big_endian>& sym, | |
d491d34e | 68 | unsigned st_shndx, bool is_ordinary, |
14b31740 | 69 | Object* object, const char* version) |
1564db8d | 70 | { |
d491d34e | 71 | this->override_base(sym, st_shndx, is_ordinary, object, version); |
1564db8d | 72 | this->value_ = sym.get_st_value(); |
ead1e424 | 73 | this->symsize_ = sym.get_st_size(); |
1564db8d ILT |
74 | } |
75 | ||
aeddab66 ILT |
76 | // Override TOSYM with symbol FROMSYM, defined in OBJECT, with version |
77 | // VERSION. This handles all aliases of TOSYM. | |
78 | ||
79 | template<int size, bool big_endian> | |
80 | void | |
81 | Symbol_table::override(Sized_symbol<size>* tosym, | |
82 | const elfcpp::Sym<size, big_endian>& fromsym, | |
d491d34e | 83 | unsigned int st_shndx, bool is_ordinary, |
aeddab66 ILT |
84 | Object* object, const char* version) |
85 | { | |
d491d34e | 86 | tosym->override(fromsym, st_shndx, is_ordinary, object, version); |
aeddab66 ILT |
87 | if (tosym->has_alias()) |
88 | { | |
89 | Symbol* sym = this->weak_aliases_[tosym]; | |
90 | gold_assert(sym != NULL); | |
7d1a9ebb | 91 | Sized_symbol<size>* ssym = this->get_sized_symbol<size>(sym); |
aeddab66 ILT |
92 | do |
93 | { | |
d491d34e | 94 | ssym->override(fromsym, st_shndx, is_ordinary, object, version); |
aeddab66 ILT |
95 | sym = this->weak_aliases_[ssym]; |
96 | gold_assert(sym != NULL); | |
7d1a9ebb | 97 | ssym = this->get_sized_symbol<size>(sym); |
aeddab66 ILT |
98 | } |
99 | while (ssym != tosym); | |
100 | } | |
101 | } | |
102 | ||
86f2e683 ILT |
103 | // The resolve functions build a little code for each symbol. |
104 | // Bit 0: 0 for global, 1 for weak. | |
105 | // Bit 1: 0 for regular object, 1 for shared object | |
106 | // Bits 2-3: 0 for normal, 1 for undefined, 2 for common | |
107 | // This gives us values from 0 to 11. | |
108 | ||
109 | static const int global_or_weak_shift = 0; | |
110 | static const unsigned int global_flag = 0 << global_or_weak_shift; | |
111 | static const unsigned int weak_flag = 1 << global_or_weak_shift; | |
112 | ||
113 | static const int regular_or_dynamic_shift = 1; | |
114 | static const unsigned int regular_flag = 0 << regular_or_dynamic_shift; | |
115 | static const unsigned int dynamic_flag = 1 << regular_or_dynamic_shift; | |
116 | ||
117 | static const int def_undef_or_common_shift = 2; | |
118 | static const unsigned int def_flag = 0 << def_undef_or_common_shift; | |
119 | static const unsigned int undef_flag = 1 << def_undef_or_common_shift; | |
120 | static const unsigned int common_flag = 2 << def_undef_or_common_shift; | |
121 | ||
70e654ba ILT |
122 | // This convenience function combines all the flags based on facts |
123 | // about the symbol. | |
124 | ||
125 | static unsigned int | |
126 | symbol_to_bits(elfcpp::STB binding, bool is_dynamic, | |
d491d34e | 127 | unsigned int shndx, bool is_ordinary, elfcpp::STT type) |
70e654ba ILT |
128 | { |
129 | unsigned int bits; | |
130 | ||
131 | switch (binding) | |
132 | { | |
133 | case elfcpp::STB_GLOBAL: | |
134 | bits = global_flag; | |
135 | break; | |
136 | ||
137 | case elfcpp::STB_WEAK: | |
138 | bits = weak_flag; | |
139 | break; | |
140 | ||
141 | case elfcpp::STB_LOCAL: | |
142 | // We should only see externally visible symbols in the symbol | |
143 | // table. | |
144 | gold_error(_("invalid STB_LOCAL symbol in external symbols")); | |
145 | bits = global_flag; | |
146 | ||
147 | default: | |
148 | // Any target which wants to handle STB_LOOS, etc., needs to | |
149 | // define a resolve method. | |
150 | gold_error(_("unsupported symbol binding")); | |
151 | bits = global_flag; | |
152 | } | |
153 | ||
154 | if (is_dynamic) | |
155 | bits |= dynamic_flag; | |
156 | else | |
157 | bits |= regular_flag; | |
158 | ||
159 | switch (shndx) | |
160 | { | |
161 | case elfcpp::SHN_UNDEF: | |
162 | bits |= undef_flag; | |
163 | break; | |
164 | ||
165 | case elfcpp::SHN_COMMON: | |
d491d34e ILT |
166 | if (!is_ordinary) |
167 | bits |= common_flag; | |
70e654ba ILT |
168 | break; |
169 | ||
170 | default: | |
171 | if (type == elfcpp::STT_COMMON) | |
172 | bits |= common_flag; | |
173 | else | |
174 | bits |= def_flag; | |
175 | break; | |
176 | } | |
177 | ||
178 | return bits; | |
179 | } | |
180 | ||
14bfc3f5 | 181 | // Resolve a symbol. This is called the second and subsequent times |
d491d34e ILT |
182 | // we see a symbol. TO is the pre-existing symbol. ST_SHNDX is the |
183 | // section index for SYM, possibly adjusted for many sections. | |
184 | // IS_ORDINARY is whether ST_SHNDX is a normal section index rather | |
185 | // than a special code. ORIG_ST_SHNDX is the original section index, | |
186 | // before any munging because of discarded sections, except that all | |
187 | // non-ordinary section indexes are mapped to SHN_UNDEF. VERSION of | |
188 | // the version of SYM. | |
14bfc3f5 ILT |
189 | |
190 | template<int size, bool big_endian> | |
191 | void | |
1564db8d | 192 | Symbol_table::resolve(Sized_symbol<size>* to, |
14bfc3f5 | 193 | const elfcpp::Sym<size, big_endian>& sym, |
d491d34e ILT |
194 | unsigned int st_shndx, bool is_ordinary, |
195 | unsigned int orig_st_shndx, | |
14b31740 | 196 | Object* object, const char* version) |
14bfc3f5 ILT |
197 | { |
198 | if (object->target()->has_resolve()) | |
199 | { | |
274e99f9 | 200 | Sized_target<size, big_endian>* sized_target; |
7d1a9ebb | 201 | sized_target = object->sized_target<size, big_endian>(); |
14b31740 | 202 | sized_target->resolve(to, sym, object, version); |
14bfc3f5 ILT |
203 | return; |
204 | } | |
205 | ||
86f2e683 ILT |
206 | if (!object->is_dynamic()) |
207 | { | |
208 | // Record that we've seen this symbol in a regular object. | |
209 | to->set_in_reg(); | |
210 | } | |
211 | else | |
212 | { | |
213 | // Record that we've seen this symbol in a dynamic object. | |
214 | to->set_in_dyn(); | |
215 | } | |
14bfc3f5 | 216 | |
70e654ba ILT |
217 | unsigned int frombits = symbol_to_bits(sym.get_st_bind(), |
218 | object->is_dynamic(), | |
d491d34e | 219 | st_shndx, is_ordinary, |
70e654ba | 220 | sym.get_st_type()); |
14bfc3f5 | 221 | |
86f2e683 | 222 | bool adjust_common_sizes; |
d20222a1 ILT |
223 | if (Symbol_table::should_override(to, frombits, object, |
224 | &adjust_common_sizes)) | |
86f2e683 ILT |
225 | { |
226 | typename Sized_symbol<size>::Size_type tosize = to->symsize(); | |
227 | ||
d491d34e | 228 | this->override(to, sym, st_shndx, is_ordinary, object, version); |
86f2e683 ILT |
229 | |
230 | if (adjust_common_sizes && tosize > to->symsize()) | |
231 | to->set_symsize(tosize); | |
232 | } | |
233 | else | |
234 | { | |
235 | if (adjust_common_sizes && sym.get_st_size() > to->symsize()) | |
236 | to->set_symsize(sym.get_st_size()); | |
237 | } | |
70e654ba ILT |
238 | |
239 | // A new weak undefined reference, merging with an old weak | |
240 | // reference, could be a One Definition Rule (ODR) violation -- | |
241 | // especially if the types or sizes of the references differ. We'll | |
242 | // store such pairs and look them up later to make sure they | |
243 | // actually refer to the same lines of code. (Note: not all ODR | |
244 | // violations can be found this way, and not everything this finds | |
245 | // is an ODR violation. But it's helpful to warn about.) | |
d491d34e | 246 | bool to_is_ordinary; |
8851ecca | 247 | if (parameters->options().detect_odr_violations() |
d491d34e | 248 | && sym.get_st_bind() == elfcpp::STB_WEAK |
70e654ba | 249 | && to->binding() == elfcpp::STB_WEAK |
d491d34e ILT |
250 | && orig_st_shndx != elfcpp::SHN_UNDEF |
251 | && to->shndx(&to_is_ordinary) != elfcpp::SHN_UNDEF | |
252 | && to_is_ordinary | |
253 | && sym.get_st_size() != 0 // Ignore weird 0-sized symbols. | |
70e654ba | 254 | && to->symsize() != 0 |
d491d34e ILT |
255 | && (sym.get_st_type() != to->type() |
256 | || sym.get_st_size() != to->symsize()) | |
70e654ba ILT |
257 | // C does not have a concept of ODR, so we only need to do this |
258 | // on C++ symbols. These have (mangled) names starting with _Z. | |
259 | && to->name()[0] == '_' && to->name()[1] == 'Z') | |
260 | { | |
a2b1aa12 | 261 | Symbol_location fromloc |
d491d34e ILT |
262 | = { object, orig_st_shndx, sym.get_st_value() }; |
263 | Symbol_location toloc = { to->object(), to->shndx(&to_is_ordinary), | |
264 | to->value() }; | |
a2b1aa12 ILT |
265 | this->candidate_odr_violations_[to->name()].insert(fromloc); |
266 | this->candidate_odr_violations_[to->name()].insert(toloc); | |
70e654ba | 267 | } |
86f2e683 ILT |
268 | } |
269 | ||
270 | // Handle the core of symbol resolution. This is called with the | |
271 | // existing symbol, TO, and a bitflag describing the new symbol. This | |
272 | // returns true if we should override the existing symbol with the new | |
273 | // one, and returns false otherwise. It sets *ADJUST_COMMON_SIZES to | |
274 | // true if we should set the symbol size to the maximum of the TO and | |
275 | // FROM sizes. It handles error conditions. | |
276 | ||
277 | bool | |
278 | Symbol_table::should_override(const Symbol* to, unsigned int frombits, | |
d20222a1 | 279 | Object* object, bool* adjust_common_sizes) |
86f2e683 ILT |
280 | { |
281 | *adjust_common_sizes = false; | |
282 | ||
e5756efb | 283 | unsigned int tobits; |
d491d34e ILT |
284 | if (to->source() != Symbol::FROM_OBJECT) |
285 | tobits = symbol_to_bits(to->binding(), false, elfcpp::SHN_ABS, false, | |
e5756efb ILT |
286 | to->type()); |
287 | else | |
d491d34e ILT |
288 | { |
289 | bool is_ordinary; | |
290 | unsigned int shndx = to->shndx(&is_ordinary); | |
291 | tobits = symbol_to_bits(to->binding(), | |
292 | to->object()->is_dynamic(), | |
293 | shndx, | |
294 | is_ordinary, | |
295 | to->type()); | |
296 | } | |
14bfc3f5 | 297 | |
1564db8d ILT |
298 | // FIXME: Warn if either but not both of TO and SYM are STT_TLS. |
299 | ||
14bfc3f5 ILT |
300 | // We use a giant switch table for symbol resolution. This code is |
301 | // unwieldy, but: 1) it is efficient; 2) we definitely handle all | |
302 | // cases; 3) it is easy to change the handling of a particular case. | |
303 | // The alternative would be a series of conditionals, but it is easy | |
304 | // to get the ordering wrong. This could also be done as a table, | |
305 | // but that is no easier to understand than this large switch | |
306 | // statement. | |
307 | ||
86f2e683 ILT |
308 | // These are the values generated by the bit codes. |
309 | enum | |
310 | { | |
311 | DEF = global_flag | regular_flag | def_flag, | |
312 | WEAK_DEF = weak_flag | regular_flag | def_flag, | |
313 | DYN_DEF = global_flag | dynamic_flag | def_flag, | |
314 | DYN_WEAK_DEF = weak_flag | dynamic_flag | def_flag, | |
315 | UNDEF = global_flag | regular_flag | undef_flag, | |
316 | WEAK_UNDEF = weak_flag | regular_flag | undef_flag, | |
317 | DYN_UNDEF = global_flag | dynamic_flag | undef_flag, | |
318 | DYN_WEAK_UNDEF = weak_flag | dynamic_flag | undef_flag, | |
319 | COMMON = global_flag | regular_flag | common_flag, | |
320 | WEAK_COMMON = weak_flag | regular_flag | common_flag, | |
321 | DYN_COMMON = global_flag | dynamic_flag | common_flag, | |
322 | DYN_WEAK_COMMON = weak_flag | dynamic_flag | common_flag | |
323 | }; | |
324 | ||
14bfc3f5 ILT |
325 | switch (tobits * 16 + frombits) |
326 | { | |
327 | case DEF * 16 + DEF: | |
12e14209 | 328 | // Two definitions of the same symbol. |
878405a8 ILT |
329 | |
330 | // If either symbol is defined by an object included using | |
331 | // --just-symbols, then don't warn. This is for compatibility | |
332 | // with the GNU linker. FIXME: This is a hack. | |
333 | if ((to->source() == Symbol::FROM_OBJECT && to->object()->just_symbols()) | |
334 | || object->just_symbols()) | |
335 | return false; | |
336 | ||
d20222a1 ILT |
337 | // FIXME: Do a better job of reporting locations. |
338 | gold_error(_("%s: multiple definition of %s"), | |
339 | object != NULL ? object->name().c_str() : _("command line"), | |
a2b1aa12 | 340 | to->demangled_name().c_str()); |
d20222a1 ILT |
341 | gold_error(_("%s: previous definition here"), |
342 | (to->source() == Symbol::FROM_OBJECT | |
343 | ? to->object()->name().c_str() | |
344 | : _("command line"))); | |
86f2e683 | 345 | return false; |
14bfc3f5 ILT |
346 | |
347 | case WEAK_DEF * 16 + DEF: | |
1564db8d ILT |
348 | // We've seen a weak definition, and now we see a strong |
349 | // definition. In the original SVR4 linker, this was treated as | |
350 | // a multiple definition error. In the Solaris linker and the | |
351 | // GNU linker, a weak definition followed by a regular | |
352 | // definition causes the weak definition to be overridden. We | |
353 | // are currently compatible with the GNU linker. In the future | |
354 | // we should add a target specific option to change this. | |
355 | // FIXME. | |
86f2e683 | 356 | return true; |
14bfc3f5 ILT |
357 | |
358 | case DYN_DEF * 16 + DEF: | |
359 | case DYN_WEAK_DEF * 16 + DEF: | |
1564db8d ILT |
360 | // We've seen a definition in a dynamic object, and now we see a |
361 | // definition in a regular object. The definition in the | |
362 | // regular object overrides the definition in the dynamic | |
363 | // object. | |
86f2e683 | 364 | return true; |
1564db8d | 365 | |
14bfc3f5 ILT |
366 | case UNDEF * 16 + DEF: |
367 | case WEAK_UNDEF * 16 + DEF: | |
368 | case DYN_UNDEF * 16 + DEF: | |
369 | case DYN_WEAK_UNDEF * 16 + DEF: | |
1564db8d ILT |
370 | // We've seen an undefined reference, and now we see a |
371 | // definition. We use the definition. | |
86f2e683 | 372 | return true; |
1564db8d | 373 | |
14bfc3f5 ILT |
374 | case COMMON * 16 + DEF: |
375 | case WEAK_COMMON * 16 + DEF: | |
376 | case DYN_COMMON * 16 + DEF: | |
377 | case DYN_WEAK_COMMON * 16 + DEF: | |
1564db8d | 378 | // We've seen a common symbol and now we see a definition. The |
14b31740 | 379 | // definition overrides. FIXME: We should optionally issue, version a |
1564db8d | 380 | // warning. |
86f2e683 | 381 | return true; |
14bfc3f5 ILT |
382 | |
383 | case DEF * 16 + WEAK_DEF: | |
384 | case WEAK_DEF * 16 + WEAK_DEF: | |
1564db8d ILT |
385 | // We've seen a definition and now we see a weak definition. We |
386 | // ignore the new weak definition. | |
86f2e683 | 387 | return false; |
1564db8d | 388 | |
14bfc3f5 ILT |
389 | case DYN_DEF * 16 + WEAK_DEF: |
390 | case DYN_WEAK_DEF * 16 + WEAK_DEF: | |
1564db8d ILT |
391 | // We've seen a dynamic definition and now we see a regular weak |
392 | // definition. The regular weak definition overrides. | |
86f2e683 | 393 | return true; |
1564db8d | 394 | |
14bfc3f5 ILT |
395 | case UNDEF * 16 + WEAK_DEF: |
396 | case WEAK_UNDEF * 16 + WEAK_DEF: | |
397 | case DYN_UNDEF * 16 + WEAK_DEF: | |
398 | case DYN_WEAK_UNDEF * 16 + WEAK_DEF: | |
1564db8d | 399 | // A weak definition of a currently undefined symbol. |
86f2e683 | 400 | return true; |
1564db8d | 401 | |
14bfc3f5 ILT |
402 | case COMMON * 16 + WEAK_DEF: |
403 | case WEAK_COMMON * 16 + WEAK_DEF: | |
1564db8d | 404 | // A weak definition does not override a common definition. |
86f2e683 | 405 | return false; |
1564db8d | 406 | |
14bfc3f5 ILT |
407 | case DYN_COMMON * 16 + WEAK_DEF: |
408 | case DYN_WEAK_COMMON * 16 + WEAK_DEF: | |
1564db8d ILT |
409 | // A weak definition does override a definition in a dynamic |
410 | // object. FIXME: We should optionally issue a warning. | |
86f2e683 | 411 | return true; |
14bfc3f5 ILT |
412 | |
413 | case DEF * 16 + DYN_DEF: | |
414 | case WEAK_DEF * 16 + DYN_DEF: | |
415 | case DYN_DEF * 16 + DYN_DEF: | |
416 | case DYN_WEAK_DEF * 16 + DYN_DEF: | |
1564db8d | 417 | // Ignore a dynamic definition if we already have a definition. |
86f2e683 | 418 | return false; |
1564db8d | 419 | |
14bfc3f5 ILT |
420 | case UNDEF * 16 + DYN_DEF: |
421 | case WEAK_UNDEF * 16 + DYN_DEF: | |
422 | case DYN_UNDEF * 16 + DYN_DEF: | |
423 | case DYN_WEAK_UNDEF * 16 + DYN_DEF: | |
1564db8d | 424 | // Use a dynamic definition if we have a reference. |
86f2e683 | 425 | return true; |
1564db8d | 426 | |
14bfc3f5 ILT |
427 | case COMMON * 16 + DYN_DEF: |
428 | case WEAK_COMMON * 16 + DYN_DEF: | |
429 | case DYN_COMMON * 16 + DYN_DEF: | |
430 | case DYN_WEAK_COMMON * 16 + DYN_DEF: | |
1564db8d ILT |
431 | // Ignore a dynamic definition if we already have a common |
432 | // definition. | |
86f2e683 | 433 | return false; |
14bfc3f5 ILT |
434 | |
435 | case DEF * 16 + DYN_WEAK_DEF: | |
436 | case WEAK_DEF * 16 + DYN_WEAK_DEF: | |
437 | case DYN_DEF * 16 + DYN_WEAK_DEF: | |
438 | case DYN_WEAK_DEF * 16 + DYN_WEAK_DEF: | |
1564db8d ILT |
439 | // Ignore a weak dynamic definition if we already have a |
440 | // definition. | |
86f2e683 | 441 | return false; |
1564db8d | 442 | |
14bfc3f5 ILT |
443 | case UNDEF * 16 + DYN_WEAK_DEF: |
444 | case WEAK_UNDEF * 16 + DYN_WEAK_DEF: | |
445 | case DYN_UNDEF * 16 + DYN_WEAK_DEF: | |
446 | case DYN_WEAK_UNDEF * 16 + DYN_WEAK_DEF: | |
1564db8d | 447 | // Use a weak dynamic definition if we have a reference. |
86f2e683 | 448 | return true; |
1564db8d | 449 | |
14bfc3f5 ILT |
450 | case COMMON * 16 + DYN_WEAK_DEF: |
451 | case WEAK_COMMON * 16 + DYN_WEAK_DEF: | |
452 | case DYN_COMMON * 16 + DYN_WEAK_DEF: | |
453 | case DYN_WEAK_COMMON * 16 + DYN_WEAK_DEF: | |
1564db8d ILT |
454 | // Ignore a weak dynamic definition if we already have a common |
455 | // definition. | |
86f2e683 | 456 | return false; |
14bfc3f5 ILT |
457 | |
458 | case DEF * 16 + UNDEF: | |
459 | case WEAK_DEF * 16 + UNDEF: | |
460 | case DYN_DEF * 16 + UNDEF: | |
461 | case DYN_WEAK_DEF * 16 + UNDEF: | |
462 | case UNDEF * 16 + UNDEF: | |
ead1e424 | 463 | // A new undefined reference tells us nothing. |
86f2e683 | 464 | return false; |
ead1e424 | 465 | |
14bfc3f5 ILT |
466 | case WEAK_UNDEF * 16 + UNDEF: |
467 | case DYN_UNDEF * 16 + UNDEF: | |
468 | case DYN_WEAK_UNDEF * 16 + UNDEF: | |
ead1e424 | 469 | // A strong undef overrides a dynamic or weak undef. |
86f2e683 | 470 | return true; |
ead1e424 | 471 | |
14bfc3f5 ILT |
472 | case COMMON * 16 + UNDEF: |
473 | case WEAK_COMMON * 16 + UNDEF: | |
474 | case DYN_COMMON * 16 + UNDEF: | |
475 | case DYN_WEAK_COMMON * 16 + UNDEF: | |
1564db8d | 476 | // A new undefined reference tells us nothing. |
86f2e683 | 477 | return false; |
14bfc3f5 ILT |
478 | |
479 | case DEF * 16 + WEAK_UNDEF: | |
480 | case WEAK_DEF * 16 + WEAK_UNDEF: | |
481 | case DYN_DEF * 16 + WEAK_UNDEF: | |
482 | case DYN_WEAK_DEF * 16 + WEAK_UNDEF: | |
483 | case UNDEF * 16 + WEAK_UNDEF: | |
484 | case WEAK_UNDEF * 16 + WEAK_UNDEF: | |
485 | case DYN_UNDEF * 16 + WEAK_UNDEF: | |
486 | case DYN_WEAK_UNDEF * 16 + WEAK_UNDEF: | |
487 | case COMMON * 16 + WEAK_UNDEF: | |
488 | case WEAK_COMMON * 16 + WEAK_UNDEF: | |
489 | case DYN_COMMON * 16 + WEAK_UNDEF: | |
490 | case DYN_WEAK_COMMON * 16 + WEAK_UNDEF: | |
1564db8d | 491 | // A new weak undefined reference tells us nothing. |
86f2e683 | 492 | return false; |
14bfc3f5 ILT |
493 | |
494 | case DEF * 16 + DYN_UNDEF: | |
495 | case WEAK_DEF * 16 + DYN_UNDEF: | |
496 | case DYN_DEF * 16 + DYN_UNDEF: | |
497 | case DYN_WEAK_DEF * 16 + DYN_UNDEF: | |
498 | case UNDEF * 16 + DYN_UNDEF: | |
499 | case WEAK_UNDEF * 16 + DYN_UNDEF: | |
500 | case DYN_UNDEF * 16 + DYN_UNDEF: | |
501 | case DYN_WEAK_UNDEF * 16 + DYN_UNDEF: | |
502 | case COMMON * 16 + DYN_UNDEF: | |
503 | case WEAK_COMMON * 16 + DYN_UNDEF: | |
504 | case DYN_COMMON * 16 + DYN_UNDEF: | |
505 | case DYN_WEAK_COMMON * 16 + DYN_UNDEF: | |
1564db8d | 506 | // A new dynamic undefined reference tells us nothing. |
86f2e683 | 507 | return false; |
14bfc3f5 ILT |
508 | |
509 | case DEF * 16 + DYN_WEAK_UNDEF: | |
510 | case WEAK_DEF * 16 + DYN_WEAK_UNDEF: | |
511 | case DYN_DEF * 16 + DYN_WEAK_UNDEF: | |
512 | case DYN_WEAK_DEF * 16 + DYN_WEAK_UNDEF: | |
513 | case UNDEF * 16 + DYN_WEAK_UNDEF: | |
514 | case WEAK_UNDEF * 16 + DYN_WEAK_UNDEF: | |
515 | case DYN_UNDEF * 16 + DYN_WEAK_UNDEF: | |
516 | case DYN_WEAK_UNDEF * 16 + DYN_WEAK_UNDEF: | |
517 | case COMMON * 16 + DYN_WEAK_UNDEF: | |
518 | case WEAK_COMMON * 16 + DYN_WEAK_UNDEF: | |
519 | case DYN_COMMON * 16 + DYN_WEAK_UNDEF: | |
520 | case DYN_WEAK_COMMON * 16 + DYN_WEAK_UNDEF: | |
1564db8d | 521 | // A new weak dynamic undefined reference tells us nothing. |
86f2e683 | 522 | return false; |
14bfc3f5 ILT |
523 | |
524 | case DEF * 16 + COMMON: | |
1564db8d | 525 | // A common symbol does not override a definition. |
86f2e683 | 526 | return false; |
1564db8d | 527 | |
14bfc3f5 ILT |
528 | case WEAK_DEF * 16 + COMMON: |
529 | case DYN_DEF * 16 + COMMON: | |
530 | case DYN_WEAK_DEF * 16 + COMMON: | |
1564db8d ILT |
531 | // A common symbol does override a weak definition or a dynamic |
532 | // definition. | |
86f2e683 | 533 | return true; |
1564db8d | 534 | |
14bfc3f5 ILT |
535 | case UNDEF * 16 + COMMON: |
536 | case WEAK_UNDEF * 16 + COMMON: | |
537 | case DYN_UNDEF * 16 + COMMON: | |
538 | case DYN_WEAK_UNDEF * 16 + COMMON: | |
1564db8d | 539 | // A common symbol is a definition for a reference. |
86f2e683 | 540 | return true; |
1564db8d | 541 | |
14bfc3f5 | 542 | case COMMON * 16 + COMMON: |
ead1e424 | 543 | // Set the size to the maximum. |
86f2e683 ILT |
544 | *adjust_common_sizes = true; |
545 | return false; | |
ead1e424 | 546 | |
14bfc3f5 | 547 | case WEAK_COMMON * 16 + COMMON: |
ead1e424 ILT |
548 | // I'm not sure just what a weak common symbol means, but |
549 | // presumably it can be overridden by a regular common symbol. | |
86f2e683 | 550 | return true; |
ead1e424 | 551 | |
14bfc3f5 ILT |
552 | case DYN_COMMON * 16 + COMMON: |
553 | case DYN_WEAK_COMMON * 16 + COMMON: | |
86f2e683 ILT |
554 | // Use the real common symbol, but adjust the size if necessary. |
555 | *adjust_common_sizes = true; | |
556 | return true; | |
14bfc3f5 ILT |
557 | |
558 | case DEF * 16 + WEAK_COMMON: | |
559 | case WEAK_DEF * 16 + WEAK_COMMON: | |
560 | case DYN_DEF * 16 + WEAK_COMMON: | |
561 | case DYN_WEAK_DEF * 16 + WEAK_COMMON: | |
ead1e424 ILT |
562 | // Whatever a weak common symbol is, it won't override a |
563 | // definition. | |
86f2e683 | 564 | return false; |
ead1e424 | 565 | |
14bfc3f5 ILT |
566 | case UNDEF * 16 + WEAK_COMMON: |
567 | case WEAK_UNDEF * 16 + WEAK_COMMON: | |
568 | case DYN_UNDEF * 16 + WEAK_COMMON: | |
569 | case DYN_WEAK_UNDEF * 16 + WEAK_COMMON: | |
ead1e424 | 570 | // A weak common symbol is better than an undefined symbol. |
86f2e683 | 571 | return true; |
ead1e424 | 572 | |
14bfc3f5 ILT |
573 | case COMMON * 16 + WEAK_COMMON: |
574 | case WEAK_COMMON * 16 + WEAK_COMMON: | |
575 | case DYN_COMMON * 16 + WEAK_COMMON: | |
576 | case DYN_WEAK_COMMON * 16 + WEAK_COMMON: | |
ead1e424 ILT |
577 | // Ignore a weak common symbol in the presence of a real common |
578 | // symbol. | |
86f2e683 | 579 | return false; |
14bfc3f5 ILT |
580 | |
581 | case DEF * 16 + DYN_COMMON: | |
582 | case WEAK_DEF * 16 + DYN_COMMON: | |
583 | case DYN_DEF * 16 + DYN_COMMON: | |
584 | case DYN_WEAK_DEF * 16 + DYN_COMMON: | |
ead1e424 ILT |
585 | // Ignore a dynamic common symbol in the presence of a |
586 | // definition. | |
86f2e683 | 587 | return false; |
ead1e424 | 588 | |
14bfc3f5 ILT |
589 | case UNDEF * 16 + DYN_COMMON: |
590 | case WEAK_UNDEF * 16 + DYN_COMMON: | |
591 | case DYN_UNDEF * 16 + DYN_COMMON: | |
592 | case DYN_WEAK_UNDEF * 16 + DYN_COMMON: | |
ead1e424 | 593 | // A dynamic common symbol is a definition of sorts. |
86f2e683 | 594 | return true; |
ead1e424 | 595 | |
14bfc3f5 ILT |
596 | case COMMON * 16 + DYN_COMMON: |
597 | case WEAK_COMMON * 16 + DYN_COMMON: | |
598 | case DYN_COMMON * 16 + DYN_COMMON: | |
599 | case DYN_WEAK_COMMON * 16 + DYN_COMMON: | |
ead1e424 | 600 | // Set the size to the maximum. |
86f2e683 ILT |
601 | *adjust_common_sizes = true; |
602 | return false; | |
14bfc3f5 ILT |
603 | |
604 | case DEF * 16 + DYN_WEAK_COMMON: | |
605 | case WEAK_DEF * 16 + DYN_WEAK_COMMON: | |
606 | case DYN_DEF * 16 + DYN_WEAK_COMMON: | |
607 | case DYN_WEAK_DEF * 16 + DYN_WEAK_COMMON: | |
ead1e424 | 608 | // A common symbol is ignored in the face of a definition. |
86f2e683 | 609 | return false; |
ead1e424 | 610 | |
14bfc3f5 ILT |
611 | case UNDEF * 16 + DYN_WEAK_COMMON: |
612 | case WEAK_UNDEF * 16 + DYN_WEAK_COMMON: | |
613 | case DYN_UNDEF * 16 + DYN_WEAK_COMMON: | |
614 | case DYN_WEAK_UNDEF * 16 + DYN_WEAK_COMMON: | |
ead1e424 | 615 | // I guess a weak common symbol is better than a definition. |
86f2e683 | 616 | return true; |
ead1e424 | 617 | |
14bfc3f5 ILT |
618 | case COMMON * 16 + DYN_WEAK_COMMON: |
619 | case WEAK_COMMON * 16 + DYN_WEAK_COMMON: | |
620 | case DYN_COMMON * 16 + DYN_WEAK_COMMON: | |
621 | case DYN_WEAK_COMMON * 16 + DYN_WEAK_COMMON: | |
ead1e424 | 622 | // Set the size to the maximum. |
86f2e683 ILT |
623 | *adjust_common_sizes = true; |
624 | return false; | |
1564db8d ILT |
625 | |
626 | default: | |
a3ad94ed | 627 | gold_unreachable(); |
14bfc3f5 ILT |
628 | } |
629 | } | |
630 | ||
86f2e683 ILT |
631 | // A special case of should_override which is only called for a strong |
632 | // defined symbol from a regular object file. This is used when | |
633 | // defining special symbols. | |
634 | ||
635 | bool | |
636 | Symbol_table::should_override_with_special(const Symbol* to) | |
637 | { | |
638 | bool adjust_common_sizes; | |
639 | unsigned int frombits = global_flag | regular_flag | def_flag; | |
d20222a1 ILT |
640 | bool ret = Symbol_table::should_override(to, frombits, NULL, |
641 | &adjust_common_sizes); | |
86f2e683 ILT |
642 | gold_assert(!adjust_common_sizes); |
643 | return ret; | |
644 | } | |
645 | ||
646 | // Override symbol base with a special symbol. | |
647 | ||
648 | void | |
649 | Symbol::override_base_with_special(const Symbol* from) | |
650 | { | |
46fe1623 ILT |
651 | gold_assert(this->name_ == from->name_ || this->has_alias()); |
652 | ||
86f2e683 ILT |
653 | this->source_ = from->source_; |
654 | switch (from->source_) | |
655 | { | |
656 | case FROM_OBJECT: | |
657 | this->u_.from_object = from->u_.from_object; | |
658 | break; | |
659 | case IN_OUTPUT_DATA: | |
660 | this->u_.in_output_data = from->u_.in_output_data; | |
661 | break; | |
662 | case IN_OUTPUT_SEGMENT: | |
663 | this->u_.in_output_segment = from->u_.in_output_segment; | |
664 | break; | |
665 | case CONSTANT: | |
666 | break; | |
667 | default: | |
668 | gold_unreachable(); | |
669 | break; | |
670 | } | |
671 | ||
672 | if (from->version_ != NULL && this->version_ != from->version_) | |
673 | { | |
674 | gold_assert(this->version_ == NULL); | |
675 | this->version_ = from->version_; | |
676 | } | |
677 | ||
678 | this->type_ = from->type_; | |
679 | this->binding_ = from->binding_; | |
680 | this->visibility_ = from->visibility_; | |
681 | this->nonvis_ = from->nonvis_; | |
682 | ||
683 | // Special symbols are always considered to be regular symbols. | |
684 | this->in_reg_ = true; | |
46fe1623 ILT |
685 | |
686 | if (from->needs_dynsym_entry_) | |
687 | this->needs_dynsym_entry_ = true; | |
688 | if (from->needs_dynsym_value_) | |
689 | this->needs_dynsym_value_ = true; | |
690 | ||
691 | // We shouldn't see these flags. If we do, we need to handle them | |
692 | // somehow. | |
693 | gold_assert(!from->is_target_special_ || this->is_target_special_); | |
694 | gold_assert(!from->is_forwarder_); | |
46fe1623 ILT |
695 | gold_assert(!from->has_plt_offset_); |
696 | gold_assert(!from->has_warning_); | |
697 | gold_assert(!from->is_copied_from_dynobj_); | |
55a93433 | 698 | gold_assert(!from->is_forced_local_); |
86f2e683 ILT |
699 | } |
700 | ||
701 | // Override a symbol with a special symbol. | |
702 | ||
703 | template<int size> | |
704 | void | |
705 | Sized_symbol<size>::override_with_special(const Sized_symbol<size>* from) | |
706 | { | |
707 | this->override_base_with_special(from); | |
708 | this->value_ = from->value_; | |
709 | this->symsize_ = from->symsize_; | |
710 | } | |
711 | ||
aeddab66 ILT |
712 | // Override TOSYM with the special symbol FROMSYM. This handles all |
713 | // aliases of TOSYM. | |
714 | ||
715 | template<int size> | |
716 | void | |
717 | Symbol_table::override_with_special(Sized_symbol<size>* tosym, | |
718 | const Sized_symbol<size>* fromsym) | |
719 | { | |
720 | tosym->override_with_special(fromsym); | |
721 | if (tosym->has_alias()) | |
722 | { | |
723 | Symbol* sym = this->weak_aliases_[tosym]; | |
724 | gold_assert(sym != NULL); | |
7d1a9ebb | 725 | Sized_symbol<size>* ssym = this->get_sized_symbol<size>(sym); |
aeddab66 ILT |
726 | do |
727 | { | |
728 | ssym->override_with_special(fromsym); | |
729 | sym = this->weak_aliases_[ssym]; | |
730 | gold_assert(sym != NULL); | |
7d1a9ebb | 731 | ssym = this->get_sized_symbol<size>(sym); |
aeddab66 ILT |
732 | } |
733 | while (ssym != tosym); | |
734 | } | |
55a93433 ILT |
735 | if (tosym->binding() == elfcpp::STB_LOCAL) |
736 | this->force_local(tosym); | |
aeddab66 ILT |
737 | } |
738 | ||
14bfc3f5 ILT |
739 | // Instantiate the templates we need. We could use the configure |
740 | // script to restrict this to only the ones needed for implemented | |
741 | // targets. | |
742 | ||
193a53d9 | 743 | #ifdef HAVE_TARGET_32_LITTLE |
14bfc3f5 ILT |
744 | template |
745 | void | |
193a53d9 | 746 | Symbol_table::resolve<32, false>( |
1564db8d | 747 | Sized_symbol<32>* to, |
193a53d9 | 748 | const elfcpp::Sym<32, false>& sym, |
d491d34e ILT |
749 | unsigned int st_shndx, |
750 | bool is_ordinary, | |
751 | unsigned int orig_st_shndx, | |
14b31740 ILT |
752 | Object* object, |
753 | const char* version); | |
193a53d9 | 754 | #endif |
14bfc3f5 | 755 | |
193a53d9 | 756 | #ifdef HAVE_TARGET_32_BIG |
14bfc3f5 ILT |
757 | template |
758 | void | |
193a53d9 | 759 | Symbol_table::resolve<32, true>( |
1564db8d | 760 | Sized_symbol<32>* to, |
193a53d9 | 761 | const elfcpp::Sym<32, true>& sym, |
d491d34e ILT |
762 | unsigned int st_shndx, |
763 | bool is_ordinary, | |
764 | unsigned int orig_st_shndx, | |
14b31740 ILT |
765 | Object* object, |
766 | const char* version); | |
193a53d9 | 767 | #endif |
14bfc3f5 | 768 | |
193a53d9 | 769 | #ifdef HAVE_TARGET_64_LITTLE |
14bfc3f5 ILT |
770 | template |
771 | void | |
193a53d9 | 772 | Symbol_table::resolve<64, false>( |
1564db8d | 773 | Sized_symbol<64>* to, |
193a53d9 | 774 | const elfcpp::Sym<64, false>& sym, |
d491d34e ILT |
775 | unsigned int st_shndx, |
776 | bool is_ordinary, | |
777 | unsigned int orig_st_shndx, | |
14b31740 ILT |
778 | Object* object, |
779 | const char* version); | |
193a53d9 | 780 | #endif |
14bfc3f5 | 781 | |
193a53d9 | 782 | #ifdef HAVE_TARGET_64_BIG |
14bfc3f5 ILT |
783 | template |
784 | void | |
193a53d9 | 785 | Symbol_table::resolve<64, true>( |
1564db8d | 786 | Sized_symbol<64>* to, |
193a53d9 | 787 | const elfcpp::Sym<64, true>& sym, |
d491d34e ILT |
788 | unsigned int st_shndx, |
789 | bool is_ordinary, | |
790 | unsigned int orig_st_shndx, | |
14b31740 ILT |
791 | Object* object, |
792 | const char* version); | |
193a53d9 | 793 | #endif |
14bfc3f5 | 794 | |
86f2e683 ILT |
795 | #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG) |
796 | template | |
797 | void | |
aeddab66 ILT |
798 | Symbol_table::override_with_special<32>(Sized_symbol<32>*, |
799 | const Sized_symbol<32>*); | |
86f2e683 ILT |
800 | #endif |
801 | ||
802 | #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG) | |
803 | template | |
804 | void | |
aeddab66 ILT |
805 | Symbol_table::override_with_special<64>(Sized_symbol<64>*, |
806 | const Sized_symbol<64>*); | |
86f2e683 ILT |
807 | #endif |
808 | ||
14bfc3f5 | 809 | } // End namespace gold. |