aboutsummaryrefslogtreecommitdiff
blob: 494ccea5a01a462c6a3775ddc748c91a5da29910 (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
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
// attributes.cc -- object attributes for gold

// Copyright (C) 2009-2019 Free Software Foundation, Inc.
// Written by Doug Kwan <dougkwan@google.com>.
// This file contains code adapted from BFD.

// This file is part of gold.

// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
// MA 02110-1301, USA.

#include "gold.h"

#include <limits>

#include "attributes.h"
#include "elfcpp.h"
#include "target.h"
#include "parameters.h"
#include "int_encoding.h"

namespace gold
{

// Object_attribute methods.

// Return size of attribute encode in ULEB128.

size_t
Object_attribute::size(int tag) const
{
  // Attributes with default values are not written out.
  if (this->is_default_attribute())
    return 0;

  size_t size = get_length_as_unsigned_LEB_128(tag);
  if (Object_attribute::attribute_type_has_int_value(this->type_))
    size += get_length_as_unsigned_LEB_128(this->int_value_);
  if (Object_attribute::attribute_type_has_string_value(this->type_))
    size += this->string_value_.size() + 1;
  return size;
}

// Whether this has the default value (0/"").

bool
Object_attribute::is_default_attribute() const
{
  if (Object_attribute::attribute_type_has_int_value(this->type_)
      && this->int_value_ != 0)
    return false;
  if (Object_attribute::attribute_type_has_string_value(this->type_)
      && !this->string_value_.empty())
    return false;
  if (Object_attribute::attribute_type_has_no_default(this->type_))
    return false;

  return true;
}

// Whether this matches another Object_attribute OA in merging.
// Two Object_attributes match if they have the same values.

bool
Object_attribute::matches(const Object_attribute& oa) const
{
  return ((this->int_value_ != oa.int_value_)
	  && (this->string_value_ == oa.string_value_));
}

// Write this with TAG to a BUFFER.

void
Object_attribute::write(
    int tag,
    std::vector<unsigned char>* buffer) const
{
  // No need to write default attributes.
  if (this->is_default_attribute())
    return;
  
  // Write tag.
  write_unsigned_LEB_128(buffer, convert_types<uint64_t, int>(tag));

  // Write integer value.
  if (Object_attribute::attribute_type_has_int_value(this->type_))
    write_unsigned_LEB_128(buffer,
			   convert_types<uint64_t, int>(this->int_value_));

  // Write string value.
  if (Object_attribute::attribute_type_has_string_value(this->type_))
    {
      const unsigned char* start =
	reinterpret_cast<const unsigned char*>(this->string_value_.c_str());
      const unsigned char* end = start + this->string_value_.size() + 1;
      buffer->insert(buffer->end(), start, end); 
    }
}

// Vendor_object_attributes methods.

// Copying constructor.

Vendor_object_attributes::Vendor_object_attributes(
    const Vendor_object_attributes& voa)
{
  this->vendor_ = voa.vendor_;

  for (int i = 0; i < NUM_KNOWN_ATTRIBUTES; ++i)
    this->known_attributes_[i] = voa.known_attributes_[i];

  // We do not handle attribute deletion.  So this must be empty.
  gold_assert(this->other_attributes_.empty());

  for (Other_attributes::const_iterator p = voa.other_attributes_.begin();
       p != voa.other_attributes_.end();
       ++p)
    this->other_attributes_[p->first] = new Object_attribute(*(p->second));
}

// Size of this in number of bytes.

size_t
Vendor_object_attributes::size() const
{
  if (this->name() == NULL)
    return 0;

  size_t data_size = 0;
  for (int i = 4; i < NUM_KNOWN_ATTRIBUTES; ++i)
    data_size += this->known_attributes_[i].size(i);

  for (Other_attributes::const_iterator p = this->other_attributes_.begin();
       p != this->other_attributes_.end();
       ++p)
    data_size += p->second->size(p->first);

  // <size> <vendor_name> NUL 0x1 <size>
  return ((data_size != 0
	   || this->vendor_ == Object_attribute::OBJ_ATTR_PROC)
	  ? data_size + strlen(this->name()) + 2 + 2 * 4
	  : 0);
}

// Return a new attribute associated with TAG.

Object_attribute*
Vendor_object_attributes::new_attribute(int tag)
{
  int type = Object_attribute::arg_type(this->vendor_, tag);

  if (tag < NUM_KNOWN_ATTRIBUTES)
    {
      this->known_attributes_[tag].set_type(type);
      return &this->known_attributes_[tag];
    }
  else
    {
      Object_attribute* attr = new Object_attribute();

      // This should be the first time we insert this.
      std::pair<Other_attributes::iterator, bool> ins =
	this->other_attributes_.insert(std::make_pair(tag, attr));
      gold_assert(ins.second);

      attr->set_type(type);
      return attr;
    }
}

// Return an attribute associated with TAG.

Object_attribute*
Vendor_object_attributes::get_attribute(int tag)
{
  if (tag < NUM_KNOWN_ATTRIBUTES)
    return &this->known_attributes_[tag];
  else
    {
      Other_attributes::iterator p =
	this->other_attributes_.find(tag);
      return p != this->other_attributes_.end() ? p->second : NULL;
    }
}

const Object_attribute*
Vendor_object_attributes::get_attribute(int tag) const
{
  if (tag < NUM_KNOWN_ATTRIBUTES)
    return &this->known_attributes_[tag];
  else
    {
      Other_attributes::const_iterator p =
	this->other_attributes_.find(tag);
      return p != this->other_attributes_.end() ? p->second : NULL;
    }
}

// Write attributes to BUFFER.

void
Vendor_object_attributes::write(std::vector<unsigned char>* buffer) const
{
  // Write subsection size.
  size_t voa_size = this->size();
  uint32_t voa_size_as_u32 = convert_types<uint32_t, size_t>(voa_size);
  insert_into_vector<32>(buffer, voa_size_as_u32);

  // Write vendor name.
  const unsigned char* vendor_start =
    reinterpret_cast<const unsigned char*>(this->name());
  size_t vendor_length = strlen(this->name()) + 1;
  const unsigned char* vendor_end = vendor_start + vendor_length;
  buffer->insert(buffer->end(), vendor_start, vendor_end);

  // Write file tag.
  buffer->push_back(Object_attribute::Tag_File);

  // Write attributes size.
  uint32_t attributes_size_as_u32 =
    convert_types<uint32_t, size_t>(voa_size - 4 - vendor_length);
  insert_into_vector<32>(buffer, attributes_size_as_u32);

  // Write known attributes, skipping any defaults.
  for (int i = 4; i < NUM_KNOWN_ATTRIBUTES; ++i)
    {
      // A target may write known attributes in a special order. 
      // Call target hook to remap tags.  Attributes_order is the identity
      // function if no re-ordering is required.
      int tag = parameters->target().attributes_order(i);
      this->known_attributes_[tag].write(tag, buffer);
    }

  // Write other attributes.
  for (Other_attributes::const_iterator q = this->other_attributes_.begin();
       q != this->other_attributes_.end();
       ++q)
    q->second->write(q->first, buffer);
}

// Attributes_section_data methods.

// Compute encoded size of this.

size_t
Attributes_section_data::size() const
{
  size_t data_size = 0;
  for(int vendor = OBJ_ATTR_FIRST; vendor <= OBJ_ATTR_LAST; ++vendor)
    data_size += this->vendor_object_attributes_[vendor]->size();

  // 'A' <sections for each vendor>
  return data_size != 0 ? data_size + 1 : 0;
}

// Construct an Attributes_section_data object by parsing section contents
// specified by VIEW and SIZE.

Attributes_section_data::Attributes_section_data(
    const unsigned char* view,
    section_size_type size)
{
  for (int vendor = OBJ_ATTR_FIRST; vendor <= OBJ_ATTR_LAST; ++vendor)
    this->vendor_object_attributes_[vendor] =
      new Vendor_object_attributes(vendor);

  const unsigned char* p = view;
  p = view;
  if (size > 0 && p != NULL && *(p++) == 'A')
    {
      size--;
      while (size > 0)
	{
	  // Size of vendor attributes section.
	  section_size_type section_size =
	    convert_to_section_size_type(read_from_pointer<32>(&p));

	  if (section_size > size)
	    section_size = size;
	  size -= section_size;

	  const char* section_name = reinterpret_cast<const char*>(p);
	  section_size_type section_name_size = strlen(section_name) + 1;
	  section_size -= section_name_size + 4;

	  int vendor;
	  const char* std_section = parameters->target().attributes_vendor();
	  if (std_section != NULL && strcmp(section_name, std_section) == 0)
	    vendor = Object_attribute::OBJ_ATTR_PROC;
	  else if (strcmp(section_name, "gnu") == 0)
	    vendor = Object_attribute::OBJ_ATTR_GNU;
	  else
	    {
	      // Other vendor section.  Ignore it.
	      p += section_name_size + section_size;
	      continue;
	    }
	  p += section_name_size;

	  while (section_size > 0)
	    {
	      const unsigned char* subsection_start = p;

	      // Read vendor subsection index and size.
	      size_t uleb128_len;
	      uint64_t val = read_unsigned_LEB_128(p, &uleb128_len);
	      p += uleb128_len;

	      int tag = convert_types<int, uint64_t>(val);
	      section_size_type subsection_size =
		convert_to_section_size_type(read_from_pointer<32>(&p));
	      section_size -= subsection_size;
	      subsection_size -= (p - subsection_start);

	      const unsigned char* end = p + subsection_size;
	      switch (tag)
		{
		case Object_attribute::Tag_File:
		  while (p < end)
		    {
		      val = read_unsigned_LEB_128(p, &uleb128_len);
		      p += uleb128_len;
		      tag = convert_types<int, uint64_t>(val);
		      Vendor_object_attributes* pvoa =
			this->vendor_object_attributes_[vendor];
		      Object_attribute* attr = pvoa->new_attribute(tag);
		      const char* string_arg;
		      unsigned int int_arg;

		      int type = Object_attribute::arg_type(vendor, tag);
		      switch (type
			      & (Object_attribute::ATTR_TYPE_FLAG_INT_VAL
				 | Object_attribute::ATTR_TYPE_FLAG_STR_VAL))
			{
			case (Object_attribute::ATTR_TYPE_FLAG_INT_VAL
			      | Object_attribute::ATTR_TYPE_FLAG_STR_VAL):
			  val = read_unsigned_LEB_128(p, &uleb128_len);
			  p += uleb128_len;
			  int_arg = convert_types<unsigned int, uint64_t>(val);
			  string_arg = reinterpret_cast<const char *>(p);
			  attr->set_int_value(int_arg);
			  p += strlen(string_arg) + 1;
			  break;
			case Object_attribute::ATTR_TYPE_FLAG_STR_VAL:
			  string_arg = reinterpret_cast<const char *>(p);
			  attr->set_string_value(string_arg);
			  p += strlen(string_arg) + 1;
			  break;
			case Object_attribute::ATTR_TYPE_FLAG_INT_VAL:
			  val = read_unsigned_LEB_128(p, &uleb128_len);
			  p += uleb128_len;
			  int_arg = convert_types<unsigned int, uint64_t>(val);
			  attr->set_int_value(int_arg);
			  break;
			default:
			  gold_unreachable();
			}
		    }
		  break;
		case Object_attribute::Tag_Section:
		case Object_attribute::Tag_Symbol:
		  // Don't have anywhere convenient to attach these.
		  // Fall through for now.
		default:
		  // Ignore things we don't know about.
		  p += subsection_size;
		  subsection_size = 0;
		  break;
		}
	    }
	}
    }
}

// Merge target-independent attributes from another Attribute_section_data
// ASD from an object called NAME into this.

void
Attributes_section_data::merge(
    const char* name,
    const Attributes_section_data* pasd)
{
  // The only common attribute is currently Tag_compatibility,
  // accepted in both processor and "gnu" sections.
  for (int vendor = OBJ_ATTR_FIRST; vendor <= OBJ_ATTR_LAST; ++vendor)
    {
      // Handle Tag_compatibility.  The tags are only compatible if the flags
      // are identical and, if the flags are '1', the strings are identical.
      // If the flags are non-zero, then we can only use the string "gnu".
      const Object_attribute* in_attr =
	&pasd->known_attributes(vendor)[Object_attribute::Tag_compatibility];
      Object_attribute* out_attr =
	&this->known_attributes(vendor)[Object_attribute::Tag_compatibility];

      if (in_attr->int_value() > 0
	  && in_attr->string_value() != "gnu")
	{
	  gold_error(_("%s: must be processed by '%s' toolchain"),
		     name, in_attr->string_value().c_str());
	  return;
	}

      if (in_attr->int_value() != out_attr->int_value()
	  || in_attr->string_value() != out_attr->string_value())
	{
	  gold_error(_("%s: object tag '%d, %s' is "
		       "incompatible with tag '%d, %s'"),
		     name, in_attr->int_value(),
		     in_attr->string_value().c_str(),
		     out_attr->int_value(),
		     out_attr->string_value().c_str());
	}
    }
}

// Write to a buffer.

void
Attributes_section_data::write(std::vector<unsigned char>* buffer) const
{
  buffer->push_back('A');
  for (int vendor = OBJ_ATTR_FIRST; vendor <= OBJ_ATTR_LAST; ++vendor)
    if (this->vendor_object_attributes_[vendor]->size() != 0)
      this->vendor_object_attributes_[vendor]->write(buffer);
}

// Methods for Output_attributes_section_data.

// Write attributes section data to file OF.

void
Output_attributes_section_data::do_write(Output_file* of)
{
  off_t offset = this->offset();
  const section_size_type oview_size =
    convert_to_section_size_type(this->data_size());
  unsigned char* const oview = of->get_output_view(offset, oview_size);

  std::vector<unsigned char> buffer;
  this->attributes_section_data_.write(&buffer);
  gold_assert(convert_to_section_size_type(buffer.size()) == oview_size);
  memcpy(oview, &buffer.front(), buffer.size());
  of->write_output_view(this->offset(), oview_size, oview);
}

} // End namespace gold.