1 : // Copyright 2012 Google Inc. All Rights Reserved.
2 : //
3 : // Licensed under the Apache License, Version 2.0 (the "License");
4 : // you may not use this file except in compliance with the License.
5 : // You may obtain a copy of the License at
6 : //
7 : // http://www.apache.org/licenses/LICENSE-2.0
8 : //
9 : // Unless required by applicable law or agreed to in writing, software
10 : // distributed under the License is distributed on an "AS IS" BASIS,
11 : // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 : // See the License for the specific language governing permissions and
13 : // limitations under the License.
14 :
15 : #include "syzygy/block_graph/block_graph.h"
16 :
17 : #include <limits>
18 :
19 : #include "base/logging.h"
20 : #include "base/stringprintf.h"
21 :
22 : namespace block_graph {
23 :
24 : namespace {
25 :
26 : COMPILE_ASSERT(BlockGraph::BLOCK_ATTRIBUTES_MAX_BIT < 32,
27 : too_many_block_attributes);
28 :
29 : // A list of printable names corresponding to block types. This needs to
30 : // be kept in sync with the BlockGraph::BlockType enum!
31 : const char* kBlockType[] = {
32 : "CODE_BLOCK", "DATA_BLOCK",
33 : };
34 : COMPILE_ASSERT(arraysize(kBlockType) == BlockGraph::BLOCK_TYPE_MAX,
35 : kBlockType_not_in_sync);
36 :
37 : // Shift all items in an offset -> item map by 'distance', provided the initial
38 : // item offset was >= @p offset.
39 : template<typename ItemType>
40 : void ShiftOffsetItemMap(BlockGraph::Offset offset,
41 : BlockGraph::Offset distance,
42 E : std::map<BlockGraph::Offset, ItemType>* items) {
43 E : DCHECK_GE(offset, 0);
44 E : DCHECK_NE(distance, 0);
45 E : DCHECK(items != NULL);
46 :
47 : typedef std::map<BlockGraph::Offset, ItemType> ItemMap;
48 :
49 : // Get iterators to all of the items that need changing.
50 E : std::vector<ItemMap::iterator> item_its;
51 E : ItemMap::iterator item_it = items->lower_bound(offset);
52 E : while (item_it != items->end()) {
53 E : item_its.push_back(item_it);
54 E : ++item_it;
55 E : }
56 :
57 : // Get the direction and bounds of the iteration. We need to walk through
58 : // the iterators in a different order depending on if we're shifting left
59 : // or right. This is to ensure that earlier shifts don't land on the values
60 : // of later unshifted offsets.
61 E : int start = 0;
62 E : int stop = item_its.size();
63 E : int step = 1;
64 E : if (distance > 0) {
65 E : start = stop - 1;
66 E : stop = -1;
67 E : step = -1;
68 : }
69 :
70 E : for (int i = start; i != stop; i += step) {
71 E : item_it = item_its[i];
72 : items->insert(std::make_pair(item_it->first + distance,
73 E : item_it->second));
74 E : items->erase(item_it);
75 E : }
76 E : }
77 :
78 : void ShiftReferences(BlockGraph::Block* block,
79 : BlockGraph::Offset offset,
80 E : BlockGraph::Offset distance) {
81 : // Make a copy of the reference map for simplicity.
82 E : BlockGraph::Block::ReferenceMap references = block->references();
83 :
84 : // Start by removing all references that have moved.
85 : BlockGraph::Block::ReferenceMap::const_iterator it =
86 E : references.lower_bound(offset);
87 E : for (; it != references.end(); ++it) {
88 E : if (it->first >= offset)
89 E : block->RemoveReference(it->first);
90 E : }
91 :
92 : // Then patch up all existing references.
93 E : it = references.begin();
94 E : for (; it != references.end(); ++it) {
95 E : BlockGraph::Reference ref(it->second);
96 E : BlockGraph::Offset new_offset(it->first);
97 :
98 : // If this is self-referential, fix the destination offset.
99 E : if (ref.referenced() == block && ref.offset() >= offset) {
100 : ref = BlockGraph::Reference(ref.type(),
101 : ref.size(),
102 : ref.referenced(),
103 : ref.offset() + distance,
104 i : ref.base() + distance);
105 : }
106 :
107 : // If its offset is past the change point, fix that.
108 E : if (it->first >= offset)
109 E : new_offset += distance;
110 :
111 : // In many cases this'll be a noop.
112 : // TODO(siggi): Optimize this.
113 E : block->SetReference(new_offset, ref);
114 E : }
115 E : }
116 :
117 : // Shift all referrers beyond @p offset by @p distance.
118 : void ShiftReferrers(BlockGraph::Block* self,
119 : BlockGraph::Offset offset,
120 : BlockGraph::Offset distance,
121 E : BlockGraph::Block::ReferrerSet* referrers) {
122 E : DCHECK_GE(offset, 0);
123 E : DCHECK_NE(distance, 0);
124 E : DCHECK(referrers != NULL);
125 :
126 : typedef BlockGraph::Block::ReferrerSet ReferrerSet;
127 : typedef BlockGraph::Reference Reference;
128 :
129 E : ReferrerSet::iterator ref_it = referrers->begin();
130 E : while (ref_it != referrers->end()) {
131 : // We need to keep around the next iterator as 'ref_it' will be invalidated
132 : // if we need to update the reference. (It will be deleted and then
133 : // recreated.)
134 E : ReferrerSet::iterator next_ref_it = ref_it;
135 E : ++next_ref_it;
136 :
137 E : BlockGraph::Block* ref_block = ref_it->first;
138 : // Our own references will have been moved already.
139 E : if (ref_block != self) {
140 E : BlockGraph::Offset ref_offset = ref_it->second;
141 :
142 E : Reference ref;
143 E : bool ref_found = ref_block->GetReference(ref_offset, &ref);
144 E : DCHECK(ref_found);
145 :
146 : // Shift the reference if need be.
147 E : if (ref.offset() >= offset) {
148 : Reference new_ref(ref.type(),
149 : ref.size(),
150 : ref.referenced(),
151 : ref.offset() + distance,
152 E : ref.base() + distance);
153 E : bool inserted = ref_block->SetReference(ref_offset, new_ref);
154 E : DCHECK(!inserted);
155 : }
156 : }
157 :
158 E : ref_it = next_ref_it;
159 E : }
160 E : }
161 :
162 i : const char* BlockAttributeToString(BlockGraph::BlockAttributeEnum attr) {
163 i : switch (attr) {
164 : #define DEFINE_CASE(name) case BlockGraph::name: return #name;
165 i : BLOCK_ATTRIBUTE_ENUM(DEFINE_CASE)
166 : #undef DEFINE_CASE
167 : default:
168 i : NOTREACHED();
169 i : return NULL;
170 : }
171 i : }
172 :
173 : } // namespace
174 :
175 i : std::string BlockGraph::BlockAttributesToString(BlockAttributes attrs) {
176 i : BlockAttributes attr = 1;
177 i : std::string s;
178 i : for (; attr < BLOCK_ATTRIBUTES_MAX; attr <<= 1) {
179 i : if (attr & attrs) {
180 i : if (!s.empty())
181 i : s.append("|");
182 i : s.append(BlockAttributeToString(static_cast<BlockAttributeEnum>(attr)));
183 : }
184 i : }
185 i : return s;
186 i : }
187 :
188 E : const char* BlockGraph::BlockTypeToString(BlockGraph::BlockType type) {
189 E : DCHECK_LE(BlockGraph::CODE_BLOCK, type);
190 E : DCHECK_GT(BlockGraph::BLOCK_TYPE_MAX, type);
191 E : return kBlockType[type];
192 E : }
193 :
194 : std::string BlockGraph::LabelAttributesToString(
195 E : BlockGraph::LabelAttributes label_attributes) {
196 : static const char* kLabelAttributes[] = {
197 : "Code", "DebugStart", "DebugEnd", "ScopeStart", "ScopeEnd",
198 : "CallSite", "JumpTable", "CaseTable", "Data", "PublicSymbol" };
199 : COMPILE_ASSERT((1 << arraysize(kLabelAttributes)) == LABEL_ATTRIBUTES_MAX,
200 : label_attribute_names_not_in_sync_with_enum);
201 :
202 E : std::string s;
203 E : for (size_t i = 0; i < arraysize(kLabelAttributes); ++i) {
204 E : if (label_attributes & (1 << i)) {
205 E : if (!s.empty())
206 E : s.append("|");
207 E : s.append(kLabelAttributes[i]);
208 : }
209 E : }
210 E : return s;
211 E : }
212 :
213 E : const core::RelativeAddress kInvalidAddress(0xFFFFFFFF);
214 :
215 : const BlockGraph::SectionId BlockGraph::kInvalidSectionId = -1;
216 :
217 : BlockGraph::BlockGraph()
218 : : next_section_id_(0),
219 E : next_block_id_(0) {
220 E : }
221 :
222 E : BlockGraph::~BlockGraph() {
223 E : }
224 :
225 : BlockGraph::Section* BlockGraph::AddSection(const base::StringPiece& name,
226 E : uint32 characteristics) {
227 E : Section new_section(next_section_id_++, name, characteristics);
228 : std::pair<SectionMap::iterator, bool> result = sections_.insert(
229 E : std::make_pair(new_section.id(), new_section));
230 E : DCHECK(result.second);
231 :
232 E : return &result.first->second;
233 E : }
234 :
235 E : BlockGraph::Section* BlockGraph::FindSection(const base::StringPiece& name) {
236 : // This is a linear scan, but thankfully images generally do not have many
237 : // sections and we do not create them very often. Fast lookup by index is
238 : // more important. If this ever becomes an issue, we could keep around a
239 : // second index by name.
240 E : SectionMap::iterator it = sections_.begin();
241 E : for (; it != sections_.end(); ++it) {
242 E : if (it->second.name() == name)
243 E : return &it->second;
244 E : }
245 :
246 E : return NULL;
247 E : }
248 :
249 : BlockGraph::Section* BlockGraph::FindOrAddSection(const base::StringPiece& name,
250 E : uint32 characteristics) {
251 E : Section* section = FindSection(name);
252 E : if (section) {
253 E : section->set_characteristic(characteristics);
254 E : return section;
255 : }
256 E : return AddSection(name, characteristics);
257 E : }
258 :
259 E : bool BlockGraph::RemoveSection(Section* section) {
260 E : DCHECK(section != NULL);
261 :
262 E : SectionMap::iterator it(sections_.find(section->id()));
263 E : if (it == sections_.end() || &it->second != section)
264 i : return false;
265 :
266 E : sections_.erase(it);
267 E : return true;
268 E : }
269 :
270 E : bool BlockGraph::RemoveSectionById(SectionId id) {
271 E : SectionMap::iterator it(sections_.find(id));
272 E : if (it == sections_.end())
273 E : return false;
274 :
275 E : sections_.erase(it);
276 E : return true;
277 E : }
278 :
279 : BlockGraph::Block* BlockGraph::AddBlock(BlockType type,
280 : Size size,
281 E : const base::StringPiece& name) {
282 E : BlockId id = ++next_block_id_;
283 : BlockMap::iterator it = blocks_.insert(
284 E : std::make_pair(id, Block(id, type, size, name, this))).first;
285 :
286 E : return &it->second;
287 E : }
288 :
289 E : bool BlockGraph::RemoveBlock(Block* block) {
290 E : DCHECK(block != NULL);
291 :
292 E : BlockMap::iterator it(blocks_.find(block->id()));
293 E : if (it == blocks_.end() || &it->second != block)
294 E : return false;
295 :
296 E : return RemoveBlockByIterator(it);
297 E : }
298 :
299 E : bool BlockGraph::RemoveBlockById(BlockId id) {
300 E : BlockMap::iterator it(blocks_.find(id));
301 E : if (it == blocks_.end())
302 E : return false;
303 :
304 E : return RemoveBlockByIterator(it);
305 E : }
306 :
307 E : BlockGraph::Section* BlockGraph::GetSectionById(SectionId id) {
308 E : SectionMap::iterator it(sections_.find(id));
309 :
310 E : if (it == sections_.end())
311 E : return NULL;
312 :
313 E : return &it->second;
314 E : }
315 :
316 E : const BlockGraph::Section* BlockGraph::GetSectionById(SectionId id) const {
317 E : SectionMap::const_iterator it(sections_.find(id));
318 :
319 E : if (it == sections_.end())
320 E : return NULL;
321 :
322 E : return &it->second;
323 E : }
324 :
325 E : BlockGraph::Block* BlockGraph::GetBlockById(BlockId id) {
326 E : BlockMap::iterator it(blocks_.find(id));
327 :
328 E : if (it == blocks_.end())
329 E : return NULL;
330 :
331 E : return &it->second;
332 E : }
333 :
334 : const BlockGraph::Block* BlockGraph::GetBlockById(BlockId id) const {
335 : BlockMap::const_iterator it(blocks_.find(id));
336 :
337 : if (it == blocks_.end())
338 : return NULL;
339 :
340 : return &it->second;
341 : }
342 :
343 E : const std::string& BlockGraph::InternString(const base::StringPiece& str) {
344 E : const std::string& raw_string = str.data();
345 E : std::set<std::string>::iterator look = string_table_.find(raw_string);
346 :
347 : // This string is not interned, add it.
348 E : if (look == string_table_.end())
349 E : look = string_table_.insert(str.data()).first;
350 :
351 E : return *look;
352 E : }
353 :
354 E : bool BlockGraph::RemoveBlockByIterator(BlockMap::iterator it) {
355 E : DCHECK(it != blocks_.end());
356 :
357 : // Verify this block is fully disconnected.
358 E : if (it->second.referrers().size() > 0 || it->second.references().size() > 0)
359 E : return false;
360 :
361 E : blocks_.erase(it);
362 :
363 E : return true;
364 E : }
365 :
366 : BlockGraph::AddressSpace::AddressSpace(BlockGraph* graph)
367 E : : graph_(graph) {
368 E : DCHECK(graph != NULL);
369 E : }
370 :
371 : BlockGraph::Block* BlockGraph::AddressSpace::AddBlock(
372 : BlockType type, RelativeAddress addr, Size size,
373 E : const base::StringPiece& name) {
374 : // First check to see that the range is clear.
375 E : AddressSpaceImpl::Range range(addr, size);
376 : AddressSpaceImpl::RangeMap::iterator it =
377 E : address_space_.FindFirstIntersection(range);
378 E : if (it != address_space_.ranges().end())
379 E : return NULL;
380 :
381 E : BlockGraph::Block* block = graph_->AddBlock(type, size, name);
382 E : DCHECK(block != NULL);
383 E : bool inserted = InsertImpl(addr, block);
384 E : DCHECK(inserted);
385 :
386 E : return block;
387 E : }
388 :
389 E : bool BlockGraph::AddressSpace::InsertBlock(RelativeAddress addr, Block* block) {
390 E : return InsertImpl(addr, block);
391 E : }
392 :
393 : BlockGraph::Block* BlockGraph::AddressSpace::GetBlockByAddress(
394 E : RelativeAddress addr) const {
395 E : return GetContainingBlock(addr, 1);
396 E : }
397 :
398 : BlockGraph::Block* BlockGraph::AddressSpace::GetContainingBlock(
399 E : RelativeAddress addr, Size size) const {
400 E : AddressSpaceImpl::Range range(addr, size);
401 : AddressSpaceImpl::RangeMap::const_iterator it =
402 E : address_space_.FindContaining(range);
403 E : if (it == address_space_.ranges().end())
404 E : return NULL;
405 :
406 E : return it->second;
407 E : }
408 :
409 : BlockGraph::Block* BlockGraph::AddressSpace::GetFirstIntersectingBlock(
410 E : RelativeAddress addr, Size size) {
411 E : AddressSpaceImpl::Range range(addr, size);
412 : AddressSpaceImpl::RangeMap::iterator it =
413 E : address_space_.FindFirstIntersection(range);
414 E : if (it == address_space_.ranges().end())
415 E : return NULL;
416 :
417 E : return it->second;
418 E : }
419 :
420 : BlockGraph::AddressSpace::RangeMapConstIterPair
421 : BlockGraph::AddressSpace::GetIntersectingBlocks(RelativeAddress address,
422 E : Size size) const {
423 E : return address_space_.FindIntersecting(Range(address, size));
424 E : }
425 :
426 : BlockGraph::AddressSpace::RangeMapIterPair
427 : BlockGraph::AddressSpace::GetIntersectingBlocks(RelativeAddress address,
428 E : Size size) {
429 E : return address_space_.FindIntersecting(Range(address, size));
430 E : }
431 :
432 : bool BlockGraph::AddressSpace::GetAddressOf(const Block* block,
433 E : RelativeAddress* addr) const {
434 E : DCHECK(block != NULL);
435 E : DCHECK(addr != NULL);
436 :
437 E : BlockAddressMap::const_iterator it(block_addresses_.find(block));
438 E : if (it == block_addresses_.end())
439 E : return false;
440 :
441 E : *addr = it->second;
442 E : return true;
443 E : }
444 :
445 E : bool BlockGraph::AddressSpace::InsertImpl(RelativeAddress addr, Block* block) {
446 E : Range range(addr, block->size());
447 E : bool inserted = address_space_.Insert(range, block);
448 E : if (!inserted)
449 E : return false;
450 :
451 E : inserted = block_addresses_.insert(std::make_pair(block, addr)).second;
452 E : DCHECK(inserted);
453 : // Update the address stored in the block.
454 E : block->set_addr(addr);
455 :
456 E : return true;
457 E : }
458 :
459 E : bool BlockGraph::AddressSpace::ContainsBlock(const Block* block) {
460 E : DCHECK(block != NULL);
461 E : return block_addresses_.count(block) != 0;
462 E : }
463 :
464 : BlockGraph::Block* BlockGraph::AddressSpace::MergeIntersectingBlocks(
465 E : const Range& range) {
466 : typedef std::vector<std::pair<RelativeAddress, BlockGraph::Block*>>
467 : BlockAddressVector;
468 :
469 : // Find all the blocks that intersect the range, keep them and their
470 : // addresses. Start by finding the first intersection, then iterate
471 : // from there until we find a block that doesn't intersect with range.
472 : AddressSpaceImpl::RangeMap::iterator address_start =
473 E : address_space_.FindFirstIntersection(range);
474 E : AddressSpaceImpl::RangeMap::iterator address_it(address_start);
475 :
476 E : BlockAddressVector intersecting;
477 : for (; address_it != address_space_.ranges().end() &&
478 E : address_it->first.Intersects(range); ++address_it) {
479 : intersecting.push_back(std::make_pair(address_it->first.start(),
480 E : address_it->second));
481 E : }
482 :
483 : // Bail if the intersection doesn't cover at least two blocks.
484 E : if (intersecting.empty())
485 i : return NULL;
486 :
487 : // In case of single-block intersection, we're done.
488 E : if (intersecting.size() == 1)
489 i : return intersecting[0].second;
490 :
491 E : DCHECK(!intersecting.empty());
492 :
493 : // Calculate the start and end addresses of the new block.
494 E : BlockGraph::Block* first_block = intersecting[0].second;
495 E : BlockGraph::Block* last_block = intersecting[intersecting.size() - 1].second;
496 E : DCHECK(first_block != NULL && last_block != NULL);
497 :
498 E : RelativeAddress begin = std::min(range.start(), intersecting[0].first);
499 : RelativeAddress end = std::max(range.start() + range.size(),
500 E : intersecting[intersecting.size() - 1].first + last_block->size());
501 :
502 E : DCHECK(begin <= range.start());
503 E : DCHECK(end >= range.start() + range.size());
504 :
505 E : base::StringPiece block_name = first_block->name();
506 E : BlockType block_type = first_block->type();
507 E : size_t section_id = first_block->section();
508 E : size_t alignment = first_block->alignment();
509 E : BlockAttributes attributes = 0;
510 :
511 E : BlockGraph::Block::SourceRanges source_ranges;
512 :
513 : // Remove the found blocks from the address space, and make sure they're all
514 : // of the same type and from the same section as the first block. Merge the
515 : // data from all the blocks as we go along, as well as the attributes and
516 : // source ranges.
517 E : std::vector<uint8> merged_data(end - begin);
518 E : bool have_data = false;
519 E : for (size_t i = 0; i < intersecting.size(); ++i) {
520 E : RelativeAddress addr = intersecting[i].first;
521 E : BlockGraph::Block* block = intersecting[i].second;
522 E : DCHECK_EQ(block_type, block->type());
523 E : DCHECK_EQ(section_id, block->section());
524 :
525 E : if (block->data() != NULL) {
526 E : have_data = true;
527 E : memcpy(&merged_data.at(addr - begin), block->data(), block->data_size());
528 : }
529 E : attributes |= block->attributes();
530 :
531 : // Merge in the source ranges from each block.
532 E : BlockGraph::Offset block_offset = addr - begin;
533 : BlockGraph::Block::SourceRanges::RangePairs::const_iterator src_it =
534 E : block->source_ranges().range_pairs().begin();
535 E : for (; src_it != block->source_ranges().range_pairs().end(); ++src_it) {
536 : // The data range is wrt to the containing block, wo we have to translate
537 : // each individual block's offset to an offset in the merged block.
538 E : BlockGraph::Offset merged_offset = block_offset + src_it->first.start();
539 : bool pushed = source_ranges.Push(
540 : BlockGraph::Block::DataRange(merged_offset, src_it->first.size()),
541 E : src_it->second);
542 E : DCHECK(pushed);
543 E : }
544 :
545 E : bool removed = address_space_.Remove(Range(addr, block->size()));
546 E : DCHECK(removed);
547 E : size_t num_removed = block_addresses_.erase(intersecting[i].second);
548 E : DCHECK_EQ(1U, num_removed);
549 E : }
550 :
551 : // Create the new block.
552 : BlockGraph::Block* new_block = AddBlock(block_type,
553 : begin, end - begin,
554 E : block_name);
555 E : DCHECK(new_block != NULL);
556 :
557 : // Set the rest of the properties for the new block.
558 E : new_block->source_ranges() = source_ranges;
559 E : new_block->set_section(section_id);
560 E : new_block->set_alignment(alignment);
561 E : new_block->set_attributes(attributes);
562 E : if (have_data) {
563 E : uint8* data = new_block->CopyData(merged_data.size(), &merged_data.at(0));
564 E : if (data == NULL) {
565 i : LOG(ERROR) << "Unable to copy merged data";
566 i : return NULL;
567 : }
568 : }
569 :
570 : // Now move all labels and references to the new block.
571 E : for (size_t i = 0; i < intersecting.size(); ++i) {
572 E : RelativeAddress addr = intersecting[i].first;
573 E : BlockGraph::Block* block = intersecting[i].second;
574 E : BlockGraph::Offset start_offset = addr - begin;
575 :
576 : // If the destination block is not a code block, preserve the old block
577 : // names as labels for debugging. We also need to make sure the label is
578 : // not empty, as that is verboten.
579 E : if (block_type != BlockGraph::CODE_BLOCK && !block->name().empty()) {
580 : new_block->SetLabel(start_offset,
581 : block->name(),
582 E : BlockGraph::DATA_LABEL);
583 : }
584 :
585 : // Move labels.
586 : BlockGraph::Block::LabelMap::const_iterator
587 E : label_it(block->labels().begin());
588 E : for (; label_it != block->labels().end(); ++label_it) {
589 : new_block->SetLabel(start_offset + label_it->first,
590 E : label_it->second);
591 E : }
592 :
593 : // Copy the reference map since we mutate the original.
594 E : BlockGraph::Block::ReferenceMap refs(block->references());
595 E : BlockGraph::Block::ReferenceMap::const_iterator ref_it(refs.begin());
596 E : for (; ref_it != refs.end(); ++ref_it) {
597 E : block->RemoveReference(ref_it->first);
598 E : new_block->SetReference(start_offset + ref_it->first, ref_it->second);
599 E : }
600 :
601 : // Redirect all referrers to the new block.
602 E : block->TransferReferrers(start_offset, new_block);
603 :
604 : // Check that we've removed all references and
605 : // referrers from the original block.
606 E : DCHECK(block->references().empty());
607 E : DCHECK(block->referrers().empty());
608 :
609 : // Remove the original block.
610 E : bool removed = graph_->RemoveBlock(block);
611 E : DCHECK(removed);
612 E : }
613 :
614 E : return new_block;
615 E : }
616 :
617 E : bool BlockGraph::Section::set_name(const base::StringPiece& name) {
618 E : if (name == NULL)
619 i : return false;
620 :
621 E : if (name.empty())
622 i : return false;
623 :
624 E : name.CopyToString(&name_);
625 E : return true;
626 E : }
627 :
628 E : bool BlockGraph::Section::Save(core::OutArchive* out_archive) const {
629 E : DCHECK(out_archive != NULL);
630 : return out_archive->Save(id_) && out_archive->Save(name_) &&
631 E : out_archive->Save(characteristics_);
632 E : }
633 :
634 E : bool BlockGraph::Section::Load(core::InArchive* in_archive) {
635 E : DCHECK(in_archive != NULL);
636 : return in_archive->Load(&id_) && in_archive->Load(&name_) &&
637 E : in_archive->Load(&characteristics_);
638 E : }
639 :
640 E : std::string BlockGraph::Label::ToString() const {
641 : return base::StringPrintf("%s (%s)",
642 : name_.c_str(),
643 E : LabelAttributesToString(attributes_).c_str());
644 E : }
645 :
646 E : bool BlockGraph::Label::IsValid() const {
647 E : return AreValidAttributes(attributes_);
648 E : }
649 :
650 E : bool BlockGraph::Label::AreValidAttributes(LabelAttributes attributes) {
651 : // A label needs to have at least one attribute.
652 E : if (attributes == 0)
653 E : return false;
654 :
655 : // TODO(chrisha): Once we make the switch to VS2010 determine where call
656 : // site labels may land. Are they at the beginning of the call
657 : // instruction (in which case they may coincide with *_START_LABEL,
658 : // *_END_LABEL and CODE_LABEL), or do they point at the address of the
659 : // call (in which case they must be completely on their own)? For now, we
660 : // simply ignore them entirely from consideration.
661 E : attributes &= ~CALL_SITE_LABEL;
662 :
663 : // Public symbols can coincide with anything, so we can basically ignore
664 : // them.
665 E : attributes &= ~PUBLIC_SYMBOL_LABEL;
666 :
667 : // A code label can coincide with a debug and scope labels. (It can coincide
668 : // with *_END_LABEL labels because of 1-byte instructions, like RET or INT.)
669 : const LabelAttributes kCodeDebugScopeLabels =
670 : CODE_LABEL | DEBUG_START_LABEL | DEBUG_END_LABEL | SCOPE_START_LABEL |
671 E : SCOPE_END_LABEL;
672 : if ((attributes & CODE_LABEL) != 0 &&
673 E : (attributes & ~kCodeDebugScopeLabels) != 0) {
674 E : return false;
675 : }
676 :
677 : // A jump table must be paired with a data label. It may also be paired
678 : // with a debug-end label if tail-call optimization has been applied by
679 : // the compiler/linker.
680 : const LabelAttributes kJumpDataLabelAttributes =
681 E : JUMP_TABLE_LABEL | DATA_LABEL;
682 E : if (attributes & JUMP_TABLE_LABEL) {
683 E : if ((attributes & kJumpDataLabelAttributes) != kJumpDataLabelAttributes)
684 E : return false;
685 : // Filter out the debug-end label if present and check that nothing else
686 : // is set.
687 E : attributes &= ~DEBUG_END_LABEL;
688 E : if ((attributes & ~kJumpDataLabelAttributes) != 0)
689 i : return false;
690 E : return true;
691 : }
692 :
693 : // A case table must be paired with a data label and nothing else.
694 : const LabelAttributes kCaseDataLabelAttributes =
695 E : CASE_TABLE_LABEL | DATA_LABEL;
696 E : if (attributes & CASE_TABLE_LABEL) {
697 E : if ((attributes & kCaseDataLabelAttributes) != kCaseDataLabelAttributes)
698 E : return false;
699 E : if ((attributes & ~kCaseDataLabelAttributes) != 0)
700 i : return false;
701 E : return true;
702 : }
703 :
704 : // If there is no case or jump label, then a data label must be on its own.
705 E : if ((attributes & DATA_LABEL) != 0 && (attributes & ~DATA_LABEL) != 0)
706 i : return false;
707 :
708 E : return true;
709 E : }
710 :
711 : BlockGraph::Block::Block(BlockGraph* block_graph)
712 : : id_(0),
713 : type_(BlockGraph::CODE_BLOCK),
714 : size_(0),
715 : alignment_(1),
716 : addr_(kInvalidAddress),
717 : block_graph_(block_graph),
718 : section_(kInvalidSectionId),
719 : attributes_(0),
720 : owns_data_(false),
721 : data_(NULL),
722 E : data_size_(0) {
723 E : DCHECK(block_graph != NULL);
724 E : }
725 :
726 : BlockGraph::Block::Block(BlockId id,
727 : BlockType type,
728 : Size size,
729 : const base::StringPiece& name,
730 : BlockGraph* block_graph)
731 : : id_(id),
732 : type_(type),
733 : size_(size),
734 : alignment_(1),
735 : name_(name.begin(), name.end()),
736 : addr_(kInvalidAddress),
737 : block_graph_(block_graph),
738 : section_(kInvalidSectionId),
739 : attributes_(0),
740 : owns_data_(false),
741 : data_(NULL),
742 E : data_size_(0) {
743 E : DCHECK(block_graph != NULL);
744 E : }
745 :
746 E : BlockGraph::Block::~Block() {
747 E : DCHECK(block_graph_ != NULL);
748 E : if (owns_data_)
749 E : delete [] data_;
750 E : }
751 :
752 E : uint8* BlockGraph::Block::AllocateRawData(size_t data_size) {
753 E : DCHECK_GT(data_size, 0u);
754 E : DCHECK_LE(data_size, size_);
755 :
756 E : uint8* new_data = new uint8[data_size];
757 E : if (!new_data)
758 i : return NULL;
759 :
760 E : if (owns_data()) {
761 i : DCHECK(data_ != NULL);
762 i : delete [] data_;
763 : }
764 :
765 E : data_ = new_data;
766 E : data_size_ = data_size;
767 E : owns_data_ = true;
768 :
769 E : return new_data;
770 E : }
771 :
772 : void BlockGraph::Block::InsertData(Offset offset,
773 : Size size,
774 E : bool always_allocate_data) {
775 E : DCHECK_GE(offset, 0);
776 E : DCHECK_LE(offset, static_cast<Offset>(size_));
777 :
778 E : if (size > 0) {
779 : // Patch up the block.
780 E : size_ += size;
781 E : ShiftOffsetItemMap(offset, size, &labels_);
782 E : ShiftReferences(this, offset, size);
783 E : ShiftReferrers(this, offset, size, &referrers_);
784 E : source_ranges_.InsertUnmappedRange(DataRange(offset, size));
785 :
786 : // Does this affect already allocated data?
787 E : if (static_cast<Size>(offset) < data_size_) {
788 : // Reallocate, shift the old data to the end, and zero out the new data.
789 E : size_t old_data_size = data_size_;
790 E : size_t bytes_to_shift = data_size_ - offset;
791 E : ResizeData(data_size_ + size);
792 E : uint8* new_data = GetMutableData();
793 E : memmove(new_data + offset + size, new_data + offset, bytes_to_shift);
794 E : memset(new_data + offset, 0, size);
795 : }
796 : }
797 :
798 : // If we've been asked to, at least make sure that the data is allocated.
799 E : if (always_allocate_data && data_size_ < offset + size)
800 E : ResizeData(offset + size);
801 :
802 : return;
803 E : }
804 :
805 E : bool BlockGraph::Block::RemoveData(Offset offset, Size size) {
806 E : DCHECK_GE(offset, 0);
807 E : DCHECK_LE(offset, static_cast<Offset>(size_));
808 :
809 E : if (size == 0)
810 i : return true;
811 :
812 : // Ensure there are no labels in this range.
813 E : if (labels_.lower_bound(offset) != labels_.lower_bound(offset + size))
814 E : return false;
815 :
816 : // Ensure that there are no references intersecting this range.
817 E : ReferenceMap::const_iterator refc_it = references_.begin();
818 E : for (; refc_it != references_.end(); ++refc_it) {
819 E : if (refc_it->first >= static_cast<Offset>(offset + size))
820 E : break;
821 E : if (static_cast<Offset>(refc_it->first + refc_it->second.size()) > offset)
822 E : return false;
823 E : }
824 :
825 : // Ensure there are no referrers pointing to the data we want to remove.
826 E : ReferrerSet::const_iterator refr_it = referrers_.begin();
827 E : for (; refr_it != referrers_.end(); ++refr_it) {
828 E : Reference ref;
829 E : if (!refr_it->first->GetReference(refr_it->second, &ref)) {
830 i : LOG(ERROR) << "Unable to get reference from referrer.";
831 i : return false;
832 : }
833 : if (ref.offset() < static_cast<Offset>(offset + size) &&
834 E : static_cast<Offset>(ref.offset() + ref.size()) > offset) {
835 E : return false;
836 : }
837 E : }
838 :
839 : // Patch up the block.
840 E : size_ -= size;
841 E : ShiftOffsetItemMap(offset + size, -static_cast<int>(size), &labels_);
842 E : ShiftReferences(this, offset + size, -static_cast<int>(size));
843 E : ShiftReferrers(this, offset + size, -static_cast<int>(size), &referrers_);
844 E : source_ranges_.RemoveMappedRange(DataRange(offset, size));
845 :
846 : // Does this affect already allocated data?
847 E : if (static_cast<Size>(offset) < data_size_) {
848 E : size_t new_data_size = data_size_ - size;
849 : // Is there data beyond the section to delete?
850 E : if (static_cast<Size>(offset + size) < data_size_) {
851 : // Shift tail data to left.
852 E : uint8* data = GetMutableData();
853 E : size_t bytes_to_shift = data_size_ - offset - size;
854 E : size_t old_data_size = data_size_;
855 : memmove(data + new_data_size - bytes_to_shift,
856 : data + old_data_size - bytes_to_shift,
857 E : bytes_to_shift);
858 E : } else {
859 E : new_data_size = offset;
860 : }
861 E : ResizeData(new_data_size);
862 : }
863 :
864 E : return true;
865 E : }
866 :
867 : bool BlockGraph::Block::InsertOrRemoveData(Offset offset,
868 : Size current_size,
869 : Size new_size,
870 E : bool always_allocate_data) {
871 E : DCHECK_GE(offset, 0);
872 E : DCHECK_LE(offset, static_cast<Offset>(size_));
873 :
874 : // If we're growing use InsertData.
875 E : if (new_size > current_size) {
876 E : Offset insert_offset = offset + current_size;
877 E : Size insert_size = new_size - current_size;
878 E : InsertData(insert_offset, insert_size, always_allocate_data);
879 E : return true;
880 : }
881 :
882 : // If we're shrinking we'll need to use RemoveData.
883 E : if (new_size < current_size) {
884 E : Offset remove_offset = offset + new_size;
885 E : Size remove_size = current_size - new_size;
886 E : if (!RemoveData(remove_offset, remove_size))
887 i : return false;
888 : // We fall through so that 'always_allocate_data' can be respected.
889 : }
890 :
891 : // If we've been asked to, at least make sure that the data is allocated.
892 E : if (always_allocate_data && data_size_ < offset + new_size)
893 E : ResizeData(offset + new_size);
894 :
895 E : return true;
896 E : }
897 :
898 E : void BlockGraph::Block::SetData(const uint8* data, size_t data_size) {
899 : DCHECK((data_size == 0 && data == NULL) ||
900 E : (data_size != 0 && data != NULL));
901 E : DCHECK(data_size <= size_);
902 :
903 E : if (owns_data_)
904 E : delete [] data_;
905 :
906 E : owns_data_ = false;
907 E : data_ = data;
908 E : data_size_ = data_size;
909 E : }
910 :
911 E : uint8* BlockGraph::Block::AllocateData(size_t size) {
912 E : uint8* new_data = AllocateRawData(size);
913 E : if (new_data == NULL)
914 i : return NULL;
915 :
916 E : ::memset(new_data, 0, size);
917 E : return new_data;
918 E : }
919 :
920 E : uint8* BlockGraph::Block::CopyData(size_t size, const void* data) {
921 E : uint8* new_data = AllocateRawData(size);
922 E : if (new_data == NULL)
923 i : return NULL;
924 :
925 E : memcpy(new_data, data, size);
926 E : return new_data;
927 E : }
928 :
929 E : const uint8* BlockGraph::Block::ResizeData(size_t new_size) {
930 E : if (new_size == data_size_)
931 E : return data_;
932 :
933 E : if (!owns_data() && new_size < data_size_) {
934 : // Not in our ownership and shrinking. We only need to adjust our length.
935 E : data_size_ = new_size;
936 E : } else {
937 : // Either our own data, or it's growing (or both). We need to reallocate.
938 E : uint8* new_data = new uint8[new_size];
939 E : if (new_data == NULL)
940 i : return NULL;
941 :
942 : // Copy the (head of the) old data.
943 E : memcpy(new_data, data_, std::min(data_size_, new_size));
944 E : if (new_size > data_size_) {
945 : // Zero the tail.
946 E : memset(new_data + data_size_, 0, new_size - data_size_);
947 : }
948 :
949 E : if (owns_data())
950 E : delete [] data_;
951 :
952 E : owns_data_ = true;
953 E : data_ = new_data;
954 E : data_size_ = new_size;
955 : }
956 :
957 E : return data_;
958 E : }
959 :
960 E : uint8* BlockGraph::Block::GetMutableData() {
961 E : DCHECK(data_size_ != 0);
962 E : DCHECK(data_ != NULL);
963 :
964 : // Make a copy if we don't already own the data.
965 E : if (!owns_data()) {
966 E : uint8* new_data = new uint8[data_size_];
967 E : if (new_data == NULL)
968 i : return NULL;
969 E : memcpy(new_data, data_, data_size_);
970 E : data_ = new_data;
971 E : owns_data_ = true;
972 : }
973 E : DCHECK(owns_data_);
974 :
975 E : return const_cast<uint8*>(data_);
976 E : }
977 :
978 E : bool BlockGraph::Block::HasExternalReferrers() const {
979 E : ReferrerSet::const_iterator it = referrers().begin();
980 E : for (; it != referrers().end(); ++it) {
981 E : if (it->first != this)
982 E : return true;
983 E : }
984 E : return false;
985 E : }
986 :
987 E : bool BlockGraph::Block::SetReference(Offset offset, const Reference& ref) {
988 E : DCHECK(ref.referenced() != NULL);
989 :
990 : // Non-code blocks can be referred to by pointers that lie outside of their
991 : // extent (due to loop induction, arrays indexed with an implicit offset,
992 : // etc). Code blocks can not be referred to in this manner, because references
993 : // in code blocks must be places where the flow of execution actually lands.
994 E : if (ref.referenced()->type() == CODE_BLOCK) {
995 : DCHECK(ref.offset() >= 0 &&
996 E : static_cast<size_t>(ref.offset()) <= ref.referenced()->size());
997 E : DCHECK(offset + ref.size() <= size());
998 : }
999 :
1000 : #if defined(DEBUG) || !defined(NDEBUG)
1001 : {
1002 : // NOTE: It might be worthwhile making SetReference return true on success,
1003 : // and false on failure as it is possible for references to conflict.
1004 : // For now we simply check for conflicts in debug builds and die an
1005 : // unglorious death if we find any.
1006 :
1007 E : if (!ref.IsValid())
1008 i : NOTREACHED() << "Trying to insert invalid reference.";
1009 :
1010 : // Examine references before us that could possibly conflict with us.
1011 E : Offset offset_begin = offset - Reference::kMaximumSize + 1;
1012 : ReferenceMap::const_iterator it =
1013 E : references_.lower_bound(offset_begin);
1014 E : for (; it != references_.end() && it->first < offset; ++it) {
1015 E : if (static_cast<Offset>(it->first + it->second.size()) > offset)
1016 i : NOTREACHED() << "Trying to insert conflicting reference.";
1017 E : }
1018 :
1019 : // Examine the reference at the same offset if there is one. We expect it to
1020 : // have the same size and type.
1021 E : if (it != references_.end() && it->first == offset) {
1022 E : if (it->second.size() != ref.size() || it->second.type() != ref.type()) {
1023 : }
1024 E : ++it;
1025 : }
1026 :
1027 : // This is the first reference after our offset. Check to see if it lands
1028 : // within the range we want to occupy.
1029 : if (it != references_.end() &&
1030 E : it->first < static_cast<Offset>(offset + ref.size())) {
1031 i : NOTREACHED() << "Trying to insert conflicting reference.";
1032 : }
1033 : }
1034 : #endif
1035 :
1036 : // Did we have an earlier reference at this location?
1037 E : ReferenceMap::iterator it(references_.find(offset));
1038 E : bool inserted = false;
1039 E : if (it != references_.end()) {
1040 : // Erase the back reference.
1041 E : BlockGraph::Block* referenced = it->second.referenced();
1042 E : Referrer referrer(this, offset);
1043 E : size_t removed = referenced->referrers_.erase(referrer);
1044 E : DCHECK_EQ(1U, removed);
1045 :
1046 : // Lastly switch the reference.
1047 E : it->second = ref;
1048 E : } else {
1049 : // It's a new reference, insert it.
1050 E : inserted = references_.insert(std::make_pair(offset, ref)).second;
1051 E : DCHECK(inserted);
1052 : }
1053 :
1054 : // Record the back-reference.
1055 E : ref.referenced()->referrers_.insert(std::make_pair(this, offset));
1056 :
1057 E : return inserted;
1058 E : }
1059 :
1060 : bool BlockGraph::Block::GetReference(Offset offset,
1061 E : Reference* reference) const {
1062 E : DCHECK(reference != NULL);
1063 E : ReferenceMap::const_iterator it(references_.find(offset));
1064 E : if (it == references_.end())
1065 E : return false;
1066 :
1067 E : *reference = it->second;
1068 E : return true;
1069 E : }
1070 :
1071 E : bool BlockGraph::Block::RemoveReference(Offset offset) {
1072 : // Do we have reference at this location?
1073 E : ReferenceMap::iterator it(references_.find(offset));
1074 E : if (it == references_.end())
1075 i : return false;
1076 :
1077 E : BlockGraph::Block* referenced = it->second.referenced();
1078 E : Referrer referrer(this, offset);
1079 E : size_t removed = referenced->referrers_.erase(referrer);
1080 E : DCHECK_EQ(1U, removed);
1081 E : references_.erase(it);
1082 :
1083 E : return true;
1084 E : }
1085 :
1086 E : bool BlockGraph::Block::RemoveAllReferences() {
1087 E : ReferenceMap::iterator it = references_.begin();
1088 E : while (it != references_.end()) {
1089 E : ReferenceMap::iterator to_remove = it;
1090 E : ++it;
1091 :
1092 : // TODO(rogerm): As an optimization, we don't need to drop intra-block
1093 : // references when disconnecting from the block_graph. Consider having
1094 : // BlockGraph::RemoveBlockByIterator() check that the block has no
1095 : // external referrers before calling this function and erasing the
1096 : // block.
1097 :
1098 : // Unregister this reference from the referred block then erase it.
1099 E : BlockGraph::Block* referenced = to_remove->second.referenced();
1100 E : Referrer referrer(this, to_remove->first);
1101 E : size_t removed = referenced->referrers_.erase(referrer);
1102 E : DCHECK_EQ(1U, removed);
1103 E : references_.erase(to_remove);
1104 E : }
1105 :
1106 E : return true;
1107 E : }
1108 :
1109 E : bool BlockGraph::Block::SetLabel(Offset offset, const Label& label) {
1110 E : DCHECK_LE(0, offset);
1111 E : DCHECK_LE(static_cast<size_t>(offset), size_);
1112 :
1113 E : VLOG(2) << name() << ": adding "
1114 : << LabelAttributesToString(label.attributes()) << " label '"
1115 : << label.name() << "' at offset " << offset << ".";
1116 :
1117 : // Try inserting the label into the label map.
1118 : std::pair<LabelMap::iterator, bool> result(
1119 E : labels_.insert(std::make_pair(offset, label)));
1120 :
1121 : // If it was freshly inserted then we're done.
1122 E : if (result.second)
1123 E : return true;
1124 :
1125 E : return false;
1126 E : }
1127 :
1128 E : bool BlockGraph::Block::GetLabel(Offset offset, Label* label) const {
1129 E : DCHECK(offset >= 0 && static_cast<size_t>(offset) <= size_);
1130 E : DCHECK(label != NULL);
1131 :
1132 E : LabelMap::const_iterator it = labels_.find(offset);
1133 E : if (it == labels_.end())
1134 E : return false;
1135 :
1136 E : *label = it->second;
1137 E : return true;
1138 E : }
1139 :
1140 E : bool BlockGraph::Block::RemoveLabel(Offset offset) {
1141 E : DCHECK(offset >= 0 && static_cast<size_t>(offset) <= size_);
1142 :
1143 E : return labels_.erase(offset) == 1;
1144 E : }
1145 :
1146 E : bool BlockGraph::Block::HasLabel(Offset offset) const {
1147 E : DCHECK(offset >= 0 && static_cast<size_t>(offset) <= size_);
1148 :
1149 E : return labels_.find(offset) != labels_.end();
1150 E : }
1151 :
1152 : bool BlockGraph::Block::TransferReferrers(Offset offset,
1153 E : Block* new_block) {
1154 : // Redirect all referrers to the new block, we copy the referrer set
1155 : // because it is otherwise mutated during iteration.
1156 E : BlockGraph::Block::ReferrerSet referrers = referrers_;
1157 E : BlockGraph::Block::ReferrerSet::const_iterator referrer_it(referrers.begin());
1158 :
1159 E : for (; referrer_it != referrers.end(); ++referrer_it) {
1160 : // Get the original reference.
1161 E : BlockGraph::Block::Referrer referrer = *referrer_it;
1162 : BlockGraph::Block::ReferenceMap::const_iterator found_ref(
1163 E : referrer.first->references().find(referrer.second));
1164 E : DCHECK(found_ref != referrer.first->references().end());
1165 E : BlockGraph::Reference ref(found_ref->second);
1166 :
1167 E : Offset new_offset = ref.offset() + offset;
1168 E : Offset new_base = ref.base() + offset;
1169 :
1170 : // Same thing as in SetReferrer, references to non-code blocks may lie
1171 : // outside the extent of the block.
1172 E : if (type_ == CODE_BLOCK) {
1173 : if (new_offset < 0 ||
1174 E : static_cast<size_t>(new_offset) > new_block->size()) {
1175 E : LOG(ERROR) << "Transferred reference lies outside of code block.";
1176 E : return false;
1177 : }
1178 : }
1179 :
1180 : // Redirect the reference to the new block with the adjusted offset.
1181 : BlockGraph::Reference new_ref(ref.type(),
1182 : ref.size(),
1183 : new_block,
1184 : new_offset,
1185 E : new_base);
1186 E : referrer.first->SetReference(referrer.second, new_ref);
1187 E : }
1188 :
1189 E : return true;
1190 E : }
1191 :
1192 : // Returns true if this block contains the given range of bytes.
1193 E : bool BlockGraph::Block::Contains(RelativeAddress address, size_t size) const {
1194 E : return (address >= addr_ && address + size <= addr_ + size_);
1195 E : }
1196 :
1197 E : bool BlockGraph::Reference::IsValid() const {
1198 : // We can't reference a NULL block.
1199 E : if (referenced_ == NULL)
1200 E : return false;
1201 :
1202 : // First see if the base address is valid for the referenced block.
1203 E : if (base_ < 0 || static_cast<size_t>(base_) >= referenced_->size())
1204 i : return false;
1205 :
1206 E : if (!IsValidTypeSize(type_, size_))
1207 i : return false;
1208 :
1209 E : return true;
1210 E : }
1211 :
1212 E : bool BlockGraph::Reference::IsValidTypeSize(ReferenceType type, Size size) {
1213 E : switch (type) {
1214 : // We see 8- and 32-bit relative JMPs.
1215 : case PC_RELATIVE_REF:
1216 E : return size == 1 || size == 4;
1217 :
1218 : // These guys are all pointer sized.
1219 : case ABSOLUTE_REF:
1220 : case RELATIVE_REF:
1221 : case FILE_OFFSET_REF:
1222 E : return size == 4;
1223 :
1224 : default:
1225 i : NOTREACHED() << "Unknown ReferenceType.";
1226 : }
1227 :
1228 i : return false;
1229 E : }
1230 :
1231 : } // namespace block_graph
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