aboutsummaryrefslogtreecommitdiff
path: root/gold/gold.cc
blob: 31598dc9e6a0efc0d93a7722eddaa20118940930 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
// ld.c -- linker main function

#include "gold.h"

#include <cstdlib>
#include <cstdio>
#include <cstring>
#include <unistd.h>

#include "options.h"
#include "workqueue.h"
#include "dirsearch.h"
#include "readsyms.h"
#include "symtab.h"
#include "common.h"
#include "object.h"
#include "layout.h"
#include "reloc.h"
#include "defstd.h"

namespace gold
{

const char* program_name;

void
gold_exit(bool status)
{
  exit(status ? EXIT_SUCCESS : EXIT_FAILURE);
}

void
gold_fatal(const char* msg, bool perrno)
{
  fprintf(stderr, "%s: ", program_name);
  if (perrno)
    perror(msg);
  else
    fprintf(stderr, "%s\n", msg);
  gold_exit(false);
}

void
gold_nomem()
{
  // We are out of memory, so try hard to print a reasonable message.
  // Note that we don't try to translate this message, since the
  // translation process itself will require memory.
  write(2, program_name, strlen(program_name));
  const char* const s = ": out of memory\n";
  write(2, s, strlen(s));
  gold_exit(false);
}

void
gold_unreachable()
{
  abort();
}

// This class arranges to run the functions done in the middle of the
// link.  It is just a closure.

class Middle_runner : public Task_function_runner
{
 public:
  Middle_runner(const General_options& options,
		const Input_objects* input_objects,
		Symbol_table* symtab,
		Layout* layout)
    : options_(options), input_objects_(input_objects), symtab_(symtab),
      layout_(layout)
  { }

  void
  run(Workqueue*);

 private:
  const General_options& options_;
  const Input_objects* input_objects_;
  Symbol_table* symtab_;
  Layout* layout_;
};

void
Middle_runner::run(Workqueue* workqueue)
{
  queue_middle_tasks(this->options_, this->input_objects_, this->symtab_,
		     this->layout_, workqueue);
}

// Queue up the initial set of tasks for this link job.

void
queue_initial_tasks(const General_options& options,
		    const Dirsearch& search_path,
		    const Command_line& cmdline,
		    Workqueue* workqueue, Input_objects* input_objects,
		    Symbol_table* symtab, Layout* layout)
{
  if (cmdline.begin() == cmdline.end())
    gold_fatal(_("no input files"), false);

  // Read the input files.  We have to add the symbols to the symbol
  // table in order.  We do this by creating a separate blocker for
  // each input file.  We associate the blocker with the following
  // input file, to give us a convenient place to delete it.
  Task_token* this_blocker = NULL;
  for (Command_line::const_iterator p = cmdline.begin();
       p != cmdline.end();
       ++p)
    {
      Task_token* next_blocker = new Task_token();
      next_blocker->add_blocker();
      workqueue->queue(new Read_symbols(options, input_objects, symtab, layout,
					search_path, *p, NULL, this_blocker,
					next_blocker));
      this_blocker = next_blocker;
    }

  workqueue->queue(new Task_function(new Middle_runner(options,
						       input_objects,
						       symtab,
						       layout),
				     this_blocker));
}

// Queue up the middle set of tasks.  These are the tasks which run
// after all the input objects have been found and all the symbols
// have been read, but before we lay out the output file.

void
queue_middle_tasks(const General_options& options,
		   const Input_objects* input_objects,
		   Symbol_table* symtab,
		   Layout* layout,
		   Workqueue* workqueue)
{
  // Predefine standard symbols.  This should be fast, so we don't
  // bother to create a task for it.
  define_standard_symbols(symtab, layout, input_objects->target());

  // Read the relocations of the input files.  We do this to find
  // which symbols are used by relocations which require a GOT and/or
  // a PLT entry, or a COPY reloc.  When we implement garbage
  // collection we will do it here by reading the relocations in a
  // breadth first search by references.
  //
  // We could also read the relocations during the first pass, and
  // mark symbols at that time.  That is how the old GNU linker works.
  // Doing that is more complex, since we may later decide to discard
  // some of the sections, and thus change our minds about the types
  // of references made to the symbols.
  Task_token* blocker = new Task_token();
  Task_token* symtab_lock = new Task_token();
  for (Input_objects::Object_list::const_iterator p = input_objects->begin();
       p != input_objects->end();
       ++p)
    {
      // We can read and process the relocations in any order.  But we
      // only want one task to write to the symbol table at a time.
      // So we queue up a task for each object to read the
      // relocations.  That task will in turn queue a task to wait
      // until it can write to the symbol table.
      blocker->add_blocker();
      workqueue->queue(new Read_relocs(options, symtab, layout, *p,
				       symtab_lock, blocker));
    }

  // Allocate common symbols.  This requires write access to the
  // symbol table, but is independent of the relocation processing.
  blocker->add_blocker();
  workqueue->queue(new Allocate_commons_task(options, symtab, layout,
  					     symtab_lock, blocker));

  // When all those tasks are complete, we can start laying out the
  // output file.
  workqueue->queue(new Task_function(new Layout_task_runner(options,
							    input_objects,
							    symtab,
							    layout),
				     blocker));
}

// Queue up the final set of tasks.  This is called at the end of
// Layout_task.

void
queue_final_tasks(const General_options& options,
		  const Input_objects* input_objects,
		  const Symbol_table* symtab,
		  const Layout* layout,
		  Workqueue* workqueue,
		  Output_file* of)
{
  // Use a blocker to block the final cleanup task.
  Task_token* final_blocker = new Task_token();

  // Queue a task for each input object to relocate the sections and
  // write out the local symbols.
  for (Input_objects::Object_list::const_iterator p = input_objects->begin();
       p != input_objects->end();
       ++p)
    {
      final_blocker->add_blocker();
      workqueue->queue(new Relocate_task(options, symtab, layout, *p, of,
					 final_blocker));
    }

  // Queue a task to write out the symbol table.
  final_blocker->add_blocker();
  workqueue->queue(new Write_symbols_task(symtab, input_objects->target(),
					  layout->sympool(), of,
					  final_blocker));

  // Queue a task to write out everything else.
  final_blocker->add_blocker();
  workqueue->queue(new Write_data_task(layout, of, final_blocker));

  // Queue a task to close the output file.  This will be blocked by
  // FINAL_BLOCKER.
  workqueue->queue(new Task_function(new Close_task_runner(of),
				     final_blocker));
}

} // End namespace gold.

using namespace gold;

int
main(int argc, char** argv)
{
#if defined (HAVE_SETLOCALE) && defined (HAVE_LC_MESSAGES)
  setlocale (LC_MESSAGES, "");
#endif
#if defined (HAVE_SETLOCALE)
  setlocale (LC_CTYPE, "");
#endif
  bindtextdomain (PACKAGE, LOCALEDIR);
  textdomain (PACKAGE);

  gold::program_name = argv[0];

  // Handle the command line options.
  gold::Command_line command_line;
  command_line.process(argc - 1, argv + 1);

  // The work queue.
  gold::Workqueue workqueue(command_line.options());

  // The list of input objects.
  Input_objects input_objects;

  // The symbol table.
  Symbol_table symtab;

  // The layout object.
  Layout layout(command_line.options());

  // Get the search path from the -L options.
  Dirsearch search_path;
  search_path.add(&workqueue, command_line.options().search_path());

  // Queue up the first set of tasks.
  queue_initial_tasks(command_line.options(), search_path,
		      command_line, &workqueue, &input_objects,
		      &symtab, &layout);

  // Run the main task processing loop.
  workqueue.process();

  gold::gold_exit(true);
}