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.
31 #include "workqueue.h"
32 #include "dirsearch.h"
44 const char* program_name
;
47 gold_exit(bool status
)
49 exit(status
? EXIT_SUCCESS
: EXIT_FAILURE
);
53 gold_fatal(const char* msg
, bool perrno
)
55 fprintf(stderr
, "%s: ", program_name
);
59 fprintf(stderr
, "%s\n", msg
);
66 // We are out of memory, so try hard to print a reasonable message.
67 // Note that we don't try to translate this message, since the
68 // translation process itself will require memory.
69 write(2, program_name
, strlen(program_name
));
70 const char* const s
= ": out of memory\n";
71 write(2, s
, strlen(s
));
75 // Handle an unreachable case.
78 do_gold_unreachable(const char* filename
, int lineno
, const char* function
)
80 fprintf(stderr
, "%s: internal error in %s, at %s:%d\n",
81 program_name
, function
, filename
, lineno
);
85 // This class arranges to run the functions done in the middle of the
86 // link. It is just a closure.
88 class Middle_runner
: public Task_function_runner
91 Middle_runner(const General_options
& options
,
92 const Input_objects
* input_objects
,
95 : options_(options
), input_objects_(input_objects
), symtab_(symtab
),
103 const General_options
& options_
;
104 const Input_objects
* input_objects_
;
105 Symbol_table
* symtab_
;
110 Middle_runner::run(Workqueue
* workqueue
)
112 queue_middle_tasks(this->options_
, this->input_objects_
, this->symtab_
,
113 this->layout_
, workqueue
);
116 // Queue up the initial set of tasks for this link job.
119 queue_initial_tasks(const General_options
& options
,
120 const Dirsearch
& search_path
,
121 const Command_line
& cmdline
,
122 Workqueue
* workqueue
, Input_objects
* input_objects
,
123 Symbol_table
* symtab
, Layout
* layout
)
125 if (cmdline
.begin() == cmdline
.end())
126 gold_fatal(_("no input files"), false);
128 // Read the input files. We have to add the symbols to the symbol
129 // table in order. We do this by creating a separate blocker for
130 // each input file. We associate the blocker with the following
131 // input file, to give us a convenient place to delete it.
132 Task_token
* this_blocker
= NULL
;
133 for (Command_line::const_iterator p
= cmdline
.begin();
137 Task_token
* next_blocker
= new Task_token();
138 next_blocker
->add_blocker();
139 workqueue
->queue(new Read_symbols(options
, input_objects
, symtab
, layout
,
140 search_path
, &*p
, NULL
, this_blocker
,
142 this_blocker
= next_blocker
;
145 workqueue
->queue(new Task_function(new Middle_runner(options
,
152 // Queue up the middle set of tasks. These are the tasks which run
153 // after all the input objects have been found and all the symbols
154 // have been read, but before we lay out the output file.
157 queue_middle_tasks(const General_options
& options
,
158 const Input_objects
* input_objects
,
159 Symbol_table
* symtab
,
161 Workqueue
* workqueue
)
163 // Now we have seen all the input files.
164 set_parameters_doing_static_link(!input_objects
->any_dynamic());
166 // Define some sections and symbols needed for a dynamic link. This
167 // handles some cases we want to see before we read the relocs.
168 layout
->create_initial_dynamic_sections(input_objects
, symtab
);
170 // Predefine standard symbols. This should be fast, so we don't
171 // bother to create a task for it.
172 define_standard_symbols(symtab
, layout
, input_objects
->target());
174 // Define __start and __stop symbols for output sections where
176 layout
->define_section_symbols(symtab
, input_objects
->target());
178 // Read the relocations of the input files. We do this to find
179 // which symbols are used by relocations which require a GOT and/or
180 // a PLT entry, or a COPY reloc. When we implement garbage
181 // collection we will do it here by reading the relocations in a
182 // breadth first search by references.
184 // We could also read the relocations during the first pass, and
185 // mark symbols at that time. That is how the old GNU linker works.
186 // Doing that is more complex, since we may later decide to discard
187 // some of the sections, and thus change our minds about the types
188 // of references made to the symbols.
189 Task_token
* blocker
= new Task_token();
190 Task_token
* symtab_lock
= new Task_token();
191 for (Input_objects::Relobj_iterator p
= input_objects
->relobj_begin();
192 p
!= input_objects
->relobj_end();
195 // We can read and process the relocations in any order. But we
196 // only want one task to write to the symbol table at a time.
197 // So we queue up a task for each object to read the
198 // relocations. That task will in turn queue a task to wait
199 // until it can write to the symbol table.
200 blocker
->add_blocker();
201 workqueue
->queue(new Read_relocs(options
, symtab
, layout
, *p
,
202 symtab_lock
, blocker
));
205 // Allocate common symbols. This requires write access to the
206 // symbol table, but is independent of the relocation processing.
207 blocker
->add_blocker();
208 workqueue
->queue(new Allocate_commons_task(options
, symtab
, layout
,
209 symtab_lock
, blocker
));
211 // When all those tasks are complete, we can start laying out the
213 workqueue
->queue(new Task_function(new Layout_task_runner(options
,
220 // Queue up the final set of tasks. This is called at the end of
224 queue_final_tasks(const General_options
& options
,
225 const Input_objects
* input_objects
,
226 const Symbol_table
* symtab
,
227 const Layout
* layout
,
228 Workqueue
* workqueue
,
231 // Use a blocker to block the final cleanup task.
232 Task_token
* final_blocker
= new Task_token();
234 // Queue a task for each input object to relocate the sections and
235 // write out the local symbols.
236 for (Input_objects::Relobj_iterator p
= input_objects
->relobj_begin();
237 p
!= input_objects
->relobj_end();
240 final_blocker
->add_blocker();
241 workqueue
->queue(new Relocate_task(options
, symtab
, layout
, *p
, of
,
245 // Queue a task to write out the symbol table.
246 final_blocker
->add_blocker();
247 workqueue
->queue(new Write_symbols_task(symtab
,
248 input_objects
->target(),
254 // Queue a task to write out everything else.
255 final_blocker
->add_blocker();
256 workqueue
->queue(new Write_data_task(layout
, symtab
, of
, final_blocker
));
258 // Queue a task to close the output file. This will be blocked by
260 workqueue
->queue(new Task_function(new Close_task_runner(of
),
264 } // End namespace gold.