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5a6f7e2d | 1 | // gold.cc -- main linker functions |
bae7f79e | 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 | ||
bae7f79e ILT |
23 | #include "gold.h" |
24 | ||
25 | #include <cstdlib> | |
26 | #include <cstdio> | |
27 | #include <cstring> | |
28 | #include <unistd.h> | |
75f2446e | 29 | #include "libiberty.h" |
bae7f79e ILT |
30 | |
31 | #include "options.h" | |
494e05f4 | 32 | #include "debug.h" |
bae7f79e ILT |
33 | #include "workqueue.h" |
34 | #include "dirsearch.h" | |
35 | #include "readsyms.h" | |
14bfc3f5 | 36 | #include "symtab.h" |
ead1e424 | 37 | #include "common.h" |
54dc6425 | 38 | #include "object.h" |
a2fb1b05 | 39 | #include "layout.h" |
61ba1cf9 | 40 | #include "reloc.h" |
ead1e424 | 41 | #include "defstd.h" |
bae7f79e ILT |
42 | |
43 | namespace gold | |
44 | { | |
45 | ||
46 | const char* program_name; | |
47 | ||
48 | void | |
49 | gold_exit(bool status) | |
50 | { | |
2d684091 | 51 | if (!status && parameters != NULL && parameters->options_valid()) |
75f2446e | 52 | unlink_if_ordinary(parameters->output_file_name()); |
bae7f79e ILT |
53 | exit(status ? EXIT_SUCCESS : EXIT_FAILURE); |
54 | } | |
55 | ||
bae7f79e ILT |
56 | void |
57 | gold_nomem() | |
58 | { | |
59 | // We are out of memory, so try hard to print a reasonable message. | |
60 | // Note that we don't try to translate this message, since the | |
61 | // translation process itself will require memory. | |
62 | write(2, program_name, strlen(program_name)); | |
63 | const char* const s = ": out of memory\n"; | |
64 | write(2, s, strlen(s)); | |
65 | gold_exit(false); | |
66 | } | |
67 | ||
a3ad94ed ILT |
68 | // Handle an unreachable case. |
69 | ||
bae7f79e | 70 | void |
a3ad94ed | 71 | do_gold_unreachable(const char* filename, int lineno, const char* function) |
bae7f79e | 72 | { |
27b7985a | 73 | fprintf(stderr, _("%s: internal error in %s, at %s:%d\n"), |
a3ad94ed ILT |
74 | program_name, function, filename, lineno); |
75 | gold_exit(false); | |
bae7f79e ILT |
76 | } |
77 | ||
92e059d8 ILT |
78 | // This class arranges to run the functions done in the middle of the |
79 | // link. It is just a closure. | |
bae7f79e | 80 | |
92e059d8 | 81 | class Middle_runner : public Task_function_runner |
bae7f79e | 82 | { |
92e059d8 ILT |
83 | public: |
84 | Middle_runner(const General_options& options, | |
85 | const Input_objects* input_objects, | |
86 | Symbol_table* symtab, | |
87 | Layout* layout) | |
88 | : options_(options), input_objects_(input_objects), symtab_(symtab), | |
89 | layout_(layout) | |
90 | { } | |
91 | ||
92 | void | |
17a1d0a9 | 93 | run(Workqueue*, const Task*); |
92e059d8 ILT |
94 | |
95 | private: | |
96 | const General_options& options_; | |
97 | const Input_objects* input_objects_; | |
98 | Symbol_table* symtab_; | |
99 | Layout* layout_; | |
100 | }; | |
bae7f79e | 101 | |
92e059d8 | 102 | void |
17a1d0a9 | 103 | Middle_runner::run(Workqueue* workqueue, const Task* task) |
92e059d8 | 104 | { |
17a1d0a9 | 105 | queue_middle_tasks(this->options_, task, this->input_objects_, this->symtab_, |
92e059d8 ILT |
106 | this->layout_, workqueue); |
107 | } | |
bae7f79e ILT |
108 | |
109 | // Queue up the initial set of tasks for this link job. | |
110 | ||
111 | void | |
112 | queue_initial_tasks(const General_options& options, | |
17a1d0a9 | 113 | Dirsearch& search_path, |
ead1e424 | 114 | const Command_line& cmdline, |
54dc6425 | 115 | Workqueue* workqueue, Input_objects* input_objects, |
12e14209 | 116 | Symbol_table* symtab, Layout* layout) |
bae7f79e | 117 | { |
e5366891 ILT |
118 | if (cmdline.begin() == cmdline.end()) |
119 | gold_fatal(_("no input files")); | |
120 | ||
fe9a4c12 ILT |
121 | int thread_count = options.thread_count_initial(); |
122 | if (thread_count == 0) | |
e5366891 | 123 | thread_count = cmdline.number_of_input_files(); |
fe9a4c12 ILT |
124 | workqueue->set_thread_count(thread_count); |
125 | ||
bae7f79e ILT |
126 | // Read the input files. We have to add the symbols to the symbol |
127 | // table in order. We do this by creating a separate blocker for | |
128 | // each input file. We associate the blocker with the following | |
129 | // input file, to give us a convenient place to delete it. | |
130 | Task_token* this_blocker = NULL; | |
ead1e424 ILT |
131 | for (Command_line::const_iterator p = cmdline.begin(); |
132 | p != cmdline.end(); | |
bae7f79e ILT |
133 | ++p) |
134 | { | |
17a1d0a9 | 135 | Task_token* next_blocker = new Task_token(true); |
bae7f79e | 136 | next_blocker->add_blocker(); |
12e14209 | 137 | workqueue->queue(new Read_symbols(options, input_objects, symtab, layout, |
17a1d0a9 | 138 | &search_path, &*p, NULL, this_blocker, |
a2fb1b05 | 139 | next_blocker)); |
bae7f79e ILT |
140 | this_blocker = next_blocker; |
141 | } | |
142 | ||
92e059d8 ILT |
143 | workqueue->queue(new Task_function(new Middle_runner(options, |
144 | input_objects, | |
145 | symtab, | |
146 | layout), | |
c7912668 ILT |
147 | this_blocker, |
148 | "Task_function Middle_runner")); | |
bae7f79e ILT |
149 | } |
150 | ||
92e059d8 ILT |
151 | // Queue up the middle set of tasks. These are the tasks which run |
152 | // after all the input objects have been found and all the symbols | |
153 | // have been read, but before we lay out the output file. | |
bae7f79e | 154 | |
92e059d8 ILT |
155 | void |
156 | queue_middle_tasks(const General_options& options, | |
17a1d0a9 | 157 | const Task* task, |
92e059d8 ILT |
158 | const Input_objects* input_objects, |
159 | Symbol_table* symtab, | |
160 | Layout* layout, | |
161 | Workqueue* workqueue) | |
61ba1cf9 | 162 | { |
2c0aeda4 ILT |
163 | if (input_objects->number_of_input_objects() == 0) |
164 | { | |
165 | // We had some input files, but we weren't able to open any of | |
166 | // them. | |
167 | gold_fatal(_("no input files")); | |
168 | } | |
169 | ||
fe9a4c12 ILT |
170 | int thread_count = options.thread_count_middle(); |
171 | if (thread_count == 0) | |
e5366891 | 172 | thread_count = input_objects->number_of_input_objects(); |
fe9a4c12 ILT |
173 | workqueue->set_thread_count(thread_count); |
174 | ||
b3b74ddc | 175 | // Now we have seen all the input files. |
436ca963 ILT |
176 | const bool doing_static_link = (!input_objects->any_dynamic() |
177 | && !parameters->output_is_shared()); | |
4eff2974 ILT |
178 | set_parameters_doing_static_link(doing_static_link); |
179 | if (!doing_static_link && options.is_static()) | |
180 | { | |
181 | // We print out just the first .so we see; there may be others. | |
75f2446e ILT |
182 | gold_error(_("cannot mix -static with dynamic object %s"), |
183 | (*input_objects->dynobj_begin())->name().c_str()); | |
4eff2974 | 184 | } |
b3b74ddc | 185 | |
494e05f4 ILT |
186 | if (is_debugging_enabled(DEBUG_SCRIPT)) |
187 | layout->script_options()->print(stderr); | |
188 | ||
e2827e5f ILT |
189 | // For each dynamic object, record whether we've seen all the |
190 | // dynamic objects that it depends upon. | |
191 | input_objects->check_dynamic_dependencies(); | |
192 | ||
70e654ba ILT |
193 | // See if any of the input definitions violate the One Definition Rule. |
194 | // TODO: if this is too slow, do this as a task, rather than inline. | |
17a1d0a9 | 195 | symtab->detect_odr_violations(task, options.output_file_name()); |
70e654ba | 196 | |
a3ad94ed ILT |
197 | // Define some sections and symbols needed for a dynamic link. This |
198 | // handles some cases we want to see before we read the relocs. | |
9b07f471 | 199 | layout->create_initial_dynamic_sections(symtab); |
a3ad94ed | 200 | |
a445fddf ILT |
201 | // Define symbols from any linker scripts. |
202 | layout->define_script_symbols(symtab); | |
203 | ||
204 | // Predefine standard symbols. | |
9b07f471 | 205 | define_standard_symbols(symtab, layout); |
ead1e424 | 206 | |
bfd58944 ILT |
207 | // Define __start and __stop symbols for output sections where |
208 | // appropriate. | |
9b07f471 | 209 | layout->define_section_symbols(symtab); |
bfd58944 | 210 | |
92e059d8 ILT |
211 | // Read the relocations of the input files. We do this to find |
212 | // which symbols are used by relocations which require a GOT and/or | |
213 | // a PLT entry, or a COPY reloc. When we implement garbage | |
214 | // collection we will do it here by reading the relocations in a | |
215 | // breadth first search by references. | |
216 | // | |
217 | // We could also read the relocations during the first pass, and | |
218 | // mark symbols at that time. That is how the old GNU linker works. | |
219 | // Doing that is more complex, since we may later decide to discard | |
220 | // some of the sections, and thus change our minds about the types | |
221 | // of references made to the symbols. | |
17a1d0a9 ILT |
222 | Task_token* blocker = new Task_token(true); |
223 | Task_token* symtab_lock = new Task_token(false); | |
f6ce93d6 ILT |
224 | for (Input_objects::Relobj_iterator p = input_objects->relobj_begin(); |
225 | p != input_objects->relobj_end(); | |
92e059d8 ILT |
226 | ++p) |
227 | { | |
228 | // We can read and process the relocations in any order. But we | |
229 | // only want one task to write to the symbol table at a time. | |
230 | // So we queue up a task for each object to read the | |
231 | // relocations. That task will in turn queue a task to wait | |
232 | // until it can write to the symbol table. | |
233 | blocker->add_blocker(); | |
ead1e424 ILT |
234 | workqueue->queue(new Read_relocs(options, symtab, layout, *p, |
235 | symtab_lock, blocker)); | |
92e059d8 ILT |
236 | } |
237 | ||
238 | // Allocate common symbols. This requires write access to the | |
239 | // symbol table, but is independent of the relocation processing. | |
ead1e424 ILT |
240 | blocker->add_blocker(); |
241 | workqueue->queue(new Allocate_commons_task(options, symtab, layout, | |
242 | symtab_lock, blocker)); | |
92e059d8 ILT |
243 | |
244 | // When all those tasks are complete, we can start laying out the | |
245 | // output file. | |
246 | workqueue->queue(new Task_function(new Layout_task_runner(options, | |
247 | input_objects, | |
248 | symtab, | |
249 | layout), | |
c7912668 ILT |
250 | blocker, |
251 | "Task_function Layout_task_runner")); | |
92e059d8 | 252 | } |
61ba1cf9 ILT |
253 | |
254 | // Queue up the final set of tasks. This is called at the end of | |
255 | // Layout_task. | |
256 | ||
257 | void | |
258 | queue_final_tasks(const General_options& options, | |
259 | const Input_objects* input_objects, | |
260 | const Symbol_table* symtab, | |
27bc2bce | 261 | Layout* layout, |
61ba1cf9 ILT |
262 | Workqueue* workqueue, |
263 | Output_file* of) | |
264 | { | |
fe9a4c12 ILT |
265 | int thread_count = options.thread_count_final(); |
266 | if (thread_count == 0) | |
e5366891 | 267 | thread_count = input_objects->number_of_input_objects(); |
fe9a4c12 ILT |
268 | workqueue->set_thread_count(thread_count); |
269 | ||
17a1d0a9 ILT |
270 | bool any_postprocessing_sections = layout->any_postprocessing_sections(); |
271 | ||
730cdc88 ILT |
272 | // Use a blocker to wait until all the input sections have been |
273 | // written out. | |
17a1d0a9 ILT |
274 | Task_token* input_sections_blocker = NULL; |
275 | if (!any_postprocessing_sections) | |
276 | input_sections_blocker = new Task_token(true); | |
730cdc88 ILT |
277 | |
278 | // Use a blocker to block any objects which have to wait for the | |
279 | // output sections to complete before they can apply relocations. | |
17a1d0a9 | 280 | Task_token* output_sections_blocker = new Task_token(true); |
730cdc88 | 281 | |
61ba1cf9 | 282 | // Use a blocker to block the final cleanup task. |
17a1d0a9 | 283 | Task_token* final_blocker = new Task_token(true); |
61ba1cf9 ILT |
284 | |
285 | // Queue a task to write out the symbol table. | |
116724f3 ILT |
286 | if (!options.strip_all()) |
287 | { | |
288 | final_blocker->add_blocker(); | |
289 | workqueue->queue(new Write_symbols_task(symtab, | |
290 | input_objects, | |
291 | layout->sympool(), | |
292 | layout->dynpool(), | |
293 | of, | |
294 | final_blocker)); | |
295 | } | |
61ba1cf9 | 296 | |
730cdc88 ILT |
297 | // Queue a task to write out the output sections. |
298 | output_sections_blocker->add_blocker(); | |
299 | final_blocker->add_blocker(); | |
300 | workqueue->queue(new Write_sections_task(layout, of, output_sections_blocker, | |
301 | final_blocker)); | |
302 | ||
61ba1cf9 ILT |
303 | // Queue a task to write out everything else. |
304 | final_blocker->add_blocker(); | |
9025d29d | 305 | workqueue->queue(new Write_data_task(layout, symtab, of, final_blocker)); |
61ba1cf9 | 306 | |
17a1d0a9 ILT |
307 | // Queue a task for each input object to relocate the sections and |
308 | // write out the local symbols. | |
309 | for (Input_objects::Relobj_iterator p = input_objects->relobj_begin(); | |
310 | p != input_objects->relobj_end(); | |
311 | ++p) | |
312 | { | |
313 | if (input_sections_blocker != NULL) | |
314 | input_sections_blocker->add_blocker(); | |
315 | final_blocker->add_blocker(); | |
316 | workqueue->queue(new Relocate_task(options, symtab, layout, *p, of, | |
317 | input_sections_blocker, | |
318 | output_sections_blocker, | |
319 | final_blocker)); | |
320 | } | |
321 | ||
730cdc88 | 322 | // Queue a task to write out the output sections which depend on |
17a1d0a9 ILT |
323 | // input sections. If there are any sections which require |
324 | // postprocessing, then we need to do this last, since it may resize | |
325 | // the output file. | |
326 | if (!any_postprocessing_sections) | |
327 | { | |
328 | final_blocker->add_blocker(); | |
329 | Task* t = new Write_after_input_sections_task(layout, of, | |
330 | input_sections_blocker, | |
331 | final_blocker); | |
332 | workqueue->queue(t); | |
333 | } | |
334 | else | |
335 | { | |
336 | Task_token *new_final_blocker = new Task_token(true); | |
337 | new_final_blocker->add_blocker(); | |
338 | Task* t = new Write_after_input_sections_task(layout, of, | |
339 | final_blocker, | |
340 | new_final_blocker); | |
341 | workqueue->queue(t); | |
342 | final_blocker = new_final_blocker; | |
343 | } | |
730cdc88 | 344 | |
61ba1cf9 ILT |
345 | // Queue a task to close the output file. This will be blocked by |
346 | // FINAL_BLOCKER. | |
92e059d8 | 347 | workqueue->queue(new Task_function(new Close_task_runner(of), |
c7912668 ILT |
348 | final_blocker, |
349 | "Task_function Close_task_runner")); | |
61ba1cf9 ILT |
350 | } |
351 | ||
352 | } // End namespace gold. |