Index: src/interpreter/source-position-table.cc |
diff --git a/src/interpreter/source-position-table.cc b/src/interpreter/source-position-table.cc |
deleted file mode 100644 |
index 579c6c48948237ad7683106891ea56c07885d50a..0000000000000000000000000000000000000000 |
--- a/src/interpreter/source-position-table.cc |
+++ /dev/null |
@@ -1,178 +0,0 @@ |
-// Copyright 2016 the V8 project authors. All rights reserved. |
-// Use of this source code is governed by a BSD-style license that can be |
-// found in the LICENSE file. |
- |
-#include "src/interpreter/source-position-table.h" |
- |
-#include "src/objects-inl.h" |
-#include "src/objects.h" |
- |
-namespace v8 { |
-namespace internal { |
-namespace interpreter { |
- |
-// We'll use a simple encoding scheme to record the source positions. |
-// Conceptually, each position consists of: |
-// - bytecode_offset: An integer index into the BytecodeArray |
-// - source_position: An integer index into the source string. |
-// - position type: Each position is either a statement or an expression. |
-// |
-// The basic idea for the encoding is to use a variable-length integer coding, |
-// where each byte contains 7 bits of payload data, and 1 'more' bit that |
-// determines whether additional bytes follow. Additionally: |
-// - we record the difference from the previous position, |
-// - we just stuff one bit for the type into the bytecode offset, |
-// - we write least-significant bits first, |
-// - we use zig-zag encoding to encode both positive and negative numbers. |
- |
-namespace { |
- |
-// Each byte is encoded as MoreBit | ValueBits. |
-class MoreBit : public BitField8<bool, 7, 1> {}; |
-class ValueBits : public BitField8<unsigned, 0, 7> {}; |
- |
-// Helper: Add the offsets from 'other' to 'value'. Also set is_statement. |
-void AddAndSetEntry(PositionTableEntry& value, |
- const PositionTableEntry& other) { |
- value.bytecode_offset += other.bytecode_offset; |
- value.source_position += other.source_position; |
- value.is_statement = other.is_statement; |
-} |
- |
-// Helper: Substract the offsets from 'other' from 'value'. |
-void SubtractFromEntry(PositionTableEntry& value, |
- const PositionTableEntry& other) { |
- value.bytecode_offset -= other.bytecode_offset; |
- value.source_position -= other.source_position; |
-} |
- |
-// Helper: Encode an integer. |
-void EncodeInt(ZoneVector<byte>& bytes, int value) { |
- // Zig-zag encoding. |
- static const int kShift = kIntSize * kBitsPerByte - 1; |
- value = ((value << 1) ^ (value >> kShift)); |
- DCHECK_GE(value, 0); |
- unsigned int encoded = static_cast<unsigned int>(value); |
- bool more; |
- do { |
- more = encoded > ValueBits::kMax; |
- bytes.push_back(MoreBit::encode(more) | |
- ValueBits::encode(encoded & ValueBits::kMask)); |
- encoded >>= ValueBits::kSize; |
- } while (more); |
-} |
- |
-// Encode a PositionTableEntry. |
-void EncodeEntry(ZoneVector<byte>& bytes, const PositionTableEntry& entry) { |
- // We only accept ascending bytecode offsets. |
- DCHECK(entry.bytecode_offset >= 0); |
- // Since bytecode_offset is not negative, we use sign to encode is_statement. |
- EncodeInt(bytes, entry.is_statement ? entry.bytecode_offset |
- : -entry.bytecode_offset - 1); |
- EncodeInt(bytes, entry.source_position); |
-} |
- |
-// Helper: Decode an integer. |
-void DecodeInt(ByteArray* bytes, int* index, int* v) { |
- byte current; |
- int shift = 0; |
- int decoded = 0; |
- bool more; |
- do { |
- current = bytes->get((*index)++); |
- decoded |= ValueBits::decode(current) << shift; |
- more = MoreBit::decode(current); |
- shift += ValueBits::kSize; |
- } while (more); |
- DCHECK_GE(decoded, 0); |
- decoded = (decoded >> 1) ^ (-(decoded & 1)); |
- *v = decoded; |
-} |
- |
-void DecodeEntry(ByteArray* bytes, int* index, PositionTableEntry* entry) { |
- int tmp; |
- DecodeInt(bytes, index, &tmp); |
- if (tmp >= 0) { |
- entry->is_statement = true; |
- entry->bytecode_offset = tmp; |
- } else { |
- entry->is_statement = false; |
- entry->bytecode_offset = -(tmp + 1); |
- } |
- DecodeInt(bytes, index, &entry->source_position); |
-} |
- |
-} // namespace |
- |
-void SourcePositionTableBuilder::AddPosition(size_t bytecode_offset, |
- int source_position, |
- bool is_statement) { |
- int offset = static_cast<int>(bytecode_offset); |
- AddEntry({offset, source_position, is_statement}); |
-} |
- |
-void SourcePositionTableBuilder::AddEntry(const PositionTableEntry& entry) { |
- PositionTableEntry tmp(entry); |
- SubtractFromEntry(tmp, previous_); |
- EncodeEntry(bytes_, tmp); |
- previous_ = entry; |
- |
- if (entry.is_statement) { |
- LOG_CODE_EVENT(isolate_, CodeLinePosInfoAddStatementPositionEvent( |
- jit_handler_data_, entry.bytecode_offset, |
- entry.source_position)); |
- } |
- LOG_CODE_EVENT(isolate_, CodeLinePosInfoAddPositionEvent( |
- jit_handler_data_, entry.bytecode_offset, |
- entry.source_position)); |
- |
-#ifdef ENABLE_SLOW_DCHECKS |
- raw_entries_.push_back(entry); |
-#endif |
-} |
- |
-Handle<ByteArray> SourcePositionTableBuilder::ToSourcePositionTable() { |
- if (bytes_.empty()) return isolate_->factory()->empty_byte_array(); |
- |
- Handle<ByteArray> table = isolate_->factory()->NewByteArray( |
- static_cast<int>(bytes_.size()), TENURED); |
- |
- MemCopy(table->GetDataStartAddress(), &*bytes_.begin(), bytes_.size()); |
- |
-#ifdef ENABLE_SLOW_DCHECKS |
- // Brute force testing: Record all positions and decode |
- // the entire table to verify they are identical. |
- auto raw = raw_entries_.begin(); |
- for (SourcePositionTableIterator encoded(*table); !encoded.done(); |
- encoded.Advance(), raw++) { |
- DCHECK(raw != raw_entries_.end()); |
- DCHECK_EQ(encoded.bytecode_offset(), raw->bytecode_offset); |
- DCHECK_EQ(encoded.source_position(), raw->source_position); |
- DCHECK_EQ(encoded.is_statement(), raw->is_statement); |
- } |
- DCHECK(raw == raw_entries_.end()); |
-#endif |
- |
- return table; |
-} |
- |
-SourcePositionTableIterator::SourcePositionTableIterator(ByteArray* byte_array) |
- : table_(byte_array), index_(0), current_() { |
- Advance(); |
-} |
- |
-void SourcePositionTableIterator::Advance() { |
- DCHECK(!done()); |
- DCHECK(index_ >= 0 && index_ <= table_->length()); |
- if (index_ == table_->length()) { |
- index_ = kDone; |
- } else { |
- PositionTableEntry tmp; |
- DecodeEntry(table_, &index_, &tmp); |
- AddAndSetEntry(current_, tmp); |
- } |
-} |
- |
-} // namespace interpreter |
-} // namespace internal |
-} // namespace v8 |