Ben Murdoch | 097c5b2 | 2016-05-18 11:27:45 +0100 | [diff] [blame^] | 1 | // Copyright 2016 the V8 project authors. All rights reserved. |
| 2 | // Use of this source code is governed by a BSD-style license that can be |
| 3 | // found in the LICENSE file. |
| 4 | |
| 5 | #include "src/interpreter/source-position-table.h" |
| 6 | |
| 7 | #include "src/assembler.h" |
| 8 | #include "src/objects-inl.h" |
| 9 | #include "src/objects.h" |
| 10 | |
| 11 | namespace v8 { |
| 12 | namespace internal { |
| 13 | namespace interpreter { |
| 14 | |
| 15 | class IsStatementField : public BitField<bool, 0, 1> {}; |
| 16 | class SourcePositionField : public BitField<int, 1, 30> {}; |
| 17 | |
| 18 | void SourcePositionTableBuilder::AddStatementPosition(size_t bytecode_offset, |
| 19 | int source_position) { |
| 20 | int offset = static_cast<int>(bytecode_offset); |
| 21 | // If a position has already been assigned to this bytecode offset, |
| 22 | // do not reassign a new statement position. |
| 23 | if (CodeOffsetHasPosition(offset)) return; |
| 24 | uint32_t encoded = IsStatementField::encode(true) | |
| 25 | SourcePositionField::encode(source_position); |
| 26 | entries_.push_back({offset, encoded}); |
| 27 | } |
| 28 | |
| 29 | void SourcePositionTableBuilder::AddExpressionPosition(size_t bytecode_offset, |
| 30 | int source_position) { |
| 31 | int offset = static_cast<int>(bytecode_offset); |
| 32 | // If a position has already been assigned to this bytecode offset, |
| 33 | // do not reassign a new statement position. |
| 34 | if (CodeOffsetHasPosition(offset)) return; |
| 35 | uint32_t encoded = IsStatementField::encode(false) | |
| 36 | SourcePositionField::encode(source_position); |
| 37 | entries_.push_back({offset, encoded}); |
| 38 | } |
| 39 | |
| 40 | void SourcePositionTableBuilder::RevertPosition(size_t bytecode_offset) { |
| 41 | int offset = static_cast<int>(bytecode_offset); |
| 42 | // If we already added a source position table entry, but the bytecode array |
| 43 | // builder ended up not outputting a bytecode for the corresponding bytecode |
| 44 | // offset, we have to remove that entry. |
| 45 | if (CodeOffsetHasPosition(offset)) entries_.pop_back(); |
| 46 | } |
| 47 | |
| 48 | Handle<FixedArray> SourcePositionTableBuilder::ToFixedArray() { |
| 49 | int length = static_cast<int>(entries_.size()); |
| 50 | Handle<FixedArray> table = |
| 51 | isolate_->factory()->NewFixedArray(length * 2, TENURED); |
| 52 | for (int i = 0; i < length; i++) { |
| 53 | table->set(i * 2, Smi::FromInt(entries_[i].bytecode_offset)); |
| 54 | table->set(i * 2 + 1, Smi::FromInt(entries_[i].source_position_and_type)); |
| 55 | } |
| 56 | return table; |
| 57 | } |
| 58 | |
| 59 | SourcePositionTableIterator::SourcePositionTableIterator( |
| 60 | BytecodeArray* bytecode_array) |
| 61 | : table_(bytecode_array->source_position_table()), |
| 62 | index_(0), |
| 63 | length_(table_->length()) { |
| 64 | DCHECK(table_->length() % 2 == 0); |
| 65 | Advance(); |
| 66 | } |
| 67 | |
| 68 | void SourcePositionTableIterator::Advance() { |
| 69 | if (index_ < length_) { |
| 70 | int new_bytecode_offset = Smi::cast(table_->get(index_))->value(); |
| 71 | // Bytecode offsets are in ascending order. |
| 72 | DCHECK(bytecode_offset_ < new_bytecode_offset || index_ == 0); |
| 73 | bytecode_offset_ = new_bytecode_offset; |
| 74 | uint32_t source_position_and_type = |
| 75 | static_cast<uint32_t>(Smi::cast(table_->get(index_ + 1))->value()); |
| 76 | is_statement_ = IsStatementField::decode(source_position_and_type); |
| 77 | source_position_ = SourcePositionField::decode(source_position_and_type); |
| 78 | } |
| 79 | index_ += 2; |
| 80 | } |
| 81 | |
| 82 | } // namespace interpreter |
| 83 | } // namespace internal |
| 84 | } // namespace v8 |