1 // gold.cc -- main linker functions
3 // Copyright 2006, 2007 Free Software Foundation, Inc.
4 // Written by Ian Lance Taylor <iant@google.com>.
6 // This file is part of gold.
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.
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.
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.
29 #include "libiberty.h"
32 #include "workqueue.h"
33 #include "dirsearch.h"
45 const char* program_name
;
48 gold_exit(bool status
)
50 if (!status
&& parameters
!= NULL
)
51 unlink_if_ordinary(parameters
->output_file_name());
52 exit(status
? EXIT_SUCCESS
: EXIT_FAILURE
);
58 // We are out of memory, so try hard to print a reasonable message.
59 // Note that we don't try to translate this message, since the
60 // translation process itself will require memory.
61 write(2, program_name
, strlen(program_name
));
62 const char* const s
= ": out of memory\n";
63 write(2, s
, strlen(s
));
67 // Handle an unreachable case.
70 do_gold_unreachable(const char* filename
, int lineno
, const char* function
)
72 fprintf(stderr
, _("%s: internal error in %s, at %s:%d\n"),
73 program_name
, function
, filename
, lineno
);
77 // This class arranges to run the functions done in the middle of the
78 // link. It is just a closure.
80 class Middle_runner
: public Task_function_runner
83 Middle_runner(const General_options
& options
,
84 const Input_objects
* input_objects
,
87 : options_(options
), input_objects_(input_objects
), symtab_(symtab
),
95 const General_options
& options_
;
96 const Input_objects
* input_objects_
;
97 Symbol_table
* symtab_
;
102 Middle_runner::run(Workqueue
* workqueue
)
104 queue_middle_tasks(this->options_
, this->input_objects_
, this->symtab_
,
105 this->layout_
, workqueue
);
108 // Queue up the initial set of tasks for this link job.
111 queue_initial_tasks(const General_options
& options
,
112 const Dirsearch
& search_path
,
113 const Command_line
& cmdline
,
114 Workqueue
* workqueue
, Input_objects
* input_objects
,
115 Symbol_table
* symtab
, Layout
* layout
)
117 if (cmdline
.begin() == cmdline
.end())
118 gold_fatal(_("no input files"));
120 // Read the input files. We have to add the symbols to the symbol
121 // table in order. We do this by creating a separate blocker for
122 // each input file. We associate the blocker with the following
123 // input file, to give us a convenient place to delete it.
124 Task_token
* this_blocker
= NULL
;
125 for (Command_line::const_iterator p
= cmdline
.begin();
129 Task_token
* next_blocker
= new Task_token();
130 next_blocker
->add_blocker();
131 workqueue
->queue(new Read_symbols(options
, input_objects
, symtab
, layout
,
132 search_path
, &*p
, NULL
, this_blocker
,
134 this_blocker
= next_blocker
;
137 workqueue
->queue(new Task_function(new Middle_runner(options
,
144 // Queue up the middle set of tasks. These are the tasks which run
145 // after all the input objects have been found and all the symbols
146 // have been read, but before we lay out the output file.
149 queue_middle_tasks(const General_options
& options
,
150 const Input_objects
* input_objects
,
151 Symbol_table
* symtab
,
153 Workqueue
* workqueue
)
155 // Now we have seen all the input files.
156 const bool doing_static_link
= !input_objects
->any_dynamic();
157 set_parameters_doing_static_link(doing_static_link
);
158 if (!doing_static_link
&& options
.is_static())
160 // We print out just the first .so we see; there may be others.
161 gold_error(_("cannot mix -static with dynamic object %s"),
162 (*input_objects
->dynobj_begin())->name().c_str());
165 // Define some sections and symbols needed for a dynamic link. This
166 // handles some cases we want to see before we read the relocs.
167 layout
->create_initial_dynamic_sections(input_objects
, symtab
);
169 // Predefine standard symbols. This should be fast, so we don't
170 // bother to create a task for it.
171 define_standard_symbols(symtab
, layout
, input_objects
->target());
173 // Define __start and __stop symbols for output sections where
175 layout
->define_section_symbols(symtab
, input_objects
->target());
177 // Read the relocations of the input files. We do this to find
178 // which symbols are used by relocations which require a GOT and/or
179 // a PLT entry, or a COPY reloc. When we implement garbage
180 // collection we will do it here by reading the relocations in a
181 // breadth first search by references.
183 // We could also read the relocations during the first pass, and
184 // mark symbols at that time. That is how the old GNU linker works.
185 // Doing that is more complex, since we may later decide to discard
186 // some of the sections, and thus change our minds about the types
187 // of references made to the symbols.
188 Task_token
* blocker
= new Task_token();
189 Task_token
* symtab_lock
= new Task_token();
190 for (Input_objects::Relobj_iterator p
= input_objects
->relobj_begin();
191 p
!= input_objects
->relobj_end();
194 // We can read and process the relocations in any order. But we
195 // only want one task to write to the symbol table at a time.
196 // So we queue up a task for each object to read the
197 // relocations. That task will in turn queue a task to wait
198 // until it can write to the symbol table.
199 blocker
->add_blocker();
200 workqueue
->queue(new Read_relocs(options
, symtab
, layout
, *p
,
201 symtab_lock
, blocker
));
204 // Allocate common symbols. This requires write access to the
205 // symbol table, but is independent of the relocation processing.
206 blocker
->add_blocker();
207 workqueue
->queue(new Allocate_commons_task(options
, symtab
, layout
,
208 symtab_lock
, blocker
));
210 // When all those tasks are complete, we can start laying out the
212 workqueue
->queue(new Task_function(new Layout_task_runner(options
,
219 // Queue up the final set of tasks. This is called at the end of
223 queue_final_tasks(const General_options
& options
,
224 const Input_objects
* input_objects
,
225 const Symbol_table
* symtab
,
226 const Layout
* layout
,
227 Workqueue
* workqueue
,
230 // Use a blocker to block the final cleanup task.
231 Task_token
* final_blocker
= new Task_token();
233 // Queue a task for each input object to relocate the sections and
234 // write out the local symbols.
235 for (Input_objects::Relobj_iterator p
= input_objects
->relobj_begin();
236 p
!= input_objects
->relobj_end();
239 final_blocker
->add_blocker();
240 workqueue
->queue(new Relocate_task(options
, symtab
, layout
, *p
, of
,
244 // Queue a task to write out the symbol table.
245 final_blocker
->add_blocker();
246 workqueue
->queue(new Write_symbols_task(symtab
,
247 input_objects
->target(),
253 // Queue a task to write out everything else.
254 final_blocker
->add_blocker();
255 workqueue
->queue(new Write_data_task(layout
, symtab
, of
, final_blocker
));
257 // Queue a task to close the output file. This will be blocked by
259 workqueue
->queue(new Task_function(new Close_task_runner(of
),
263 } // End namespace gold.
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