blob: a42c6a44a3cfa758893b19172b8d2ed172f69088 [file] [log] [blame]
// 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/base/export-template.h"
#include "src/codegen/source-position.h"
#include "src/common/assert-scope.h"
#include "src/common/checks.h"
#include "src/common/globals.h"
#include "src/utils/vector.h"
#include "src/zone/zone-containers.h"
namespace v8 {
namespace internal {
class ByteArray;
template <typename T>
class Handle;
class Isolate;
class Zone;
struct PositionTableEntry {
: code_offset(kFunctionEntryBytecodeOffset),
is_statement(false) {}
PositionTableEntry(int offset, int64_t source, bool statement)
: code_offset(offset), source_position(source), is_statement(statement) {}
int code_offset;
int64_t source_position;
bool is_statement;
class V8_EXPORT_PRIVATE SourcePositionTableBuilder {
enum RecordingMode {
// Indicates that source positions are never to be generated. (Resulting in
// an empty table).
// Indicates that source positions are not currently required, but may be
// generated later.
// Indicates that source positions should be immediately generated.
explicit SourcePositionTableBuilder(
Zone* zone, RecordingMode mode = RECORD_SOURCE_POSITIONS);
void AddPosition(size_t code_offset, SourcePosition source_position,
bool is_statement);
template <typename LocalIsolate>
Handle<ByteArray> ToSourcePositionTable(LocalIsolate* isolate);
OwnedVector<byte> ToSourcePositionTableVector();
inline bool Omit() const { return mode_ != RECORD_SOURCE_POSITIONS; }
inline bool Lazy() const { return mode_ == LAZY_SOURCE_POSITIONS; }
void AddEntry(const PositionTableEntry& entry);
RecordingMode mode_;
ZoneVector<byte> bytes_;
ZoneVector<PositionTableEntry> raw_entries_;
PositionTableEntry previous_; // Previously written entry, to compute delta.
class V8_EXPORT_PRIVATE SourcePositionTableIterator {
// Filter that applies when advancing the iterator. If the filter isn't
// satisfied, we advance the iterator again.
enum IterationFilter { kJavaScriptOnly = 0, kExternalOnly = 1, kAll = 2 };
// Filter that applies only to the first entry of the source position table.
// If it is kSkipFunctionEntry, it will skip the FunctionEntry entry if it
// exists.
enum FunctionEntryFilter {
kSkipFunctionEntry = 0,
kDontSkipFunctionEntry = 1
// Used for saving/restoring the iterator.
struct IndexAndPositionState {
int index_;
PositionTableEntry position_;
IterationFilter iteration_filter_;
FunctionEntryFilter function_entry_filter_;
// We expose three flavours of the iterator, depending on the argument passed
// to the constructor:
// Handlified iterator allows allocation, but it needs a handle (and thus
// a handle scope). This is the preferred version.
explicit SourcePositionTableIterator(
Handle<ByteArray> byte_array,
IterationFilter iteration_filter = kJavaScriptOnly,
FunctionEntryFilter function_entry_filter = kSkipFunctionEntry);
// Non-handlified iterator does not need a handle scope, but it disallows
// allocation during its lifetime. This is useful if there is no handle
// scope around.
explicit SourcePositionTableIterator(
ByteArray byte_array, IterationFilter iteration_filter = kJavaScriptOnly,
FunctionEntryFilter function_entry_filter = kSkipFunctionEntry);
// Handle-safe iterator based on an a vector located outside the garbage
// collected heap, allows allocation during its lifetime.
explicit SourcePositionTableIterator(
Vector<const byte> bytes,
IterationFilter iteration_filter = kJavaScriptOnly,
FunctionEntryFilter function_entry_filter = kSkipFunctionEntry);
void Advance();
int code_offset() const {
return current_.code_offset;
SourcePosition source_position() const {
return SourcePosition::FromRaw(current_.source_position);
bool is_statement() const {
return current_.is_statement;
bool done() const { return index_ == kDone; }
IndexAndPositionState GetState() const {
return {index_, current_, iteration_filter_, function_entry_filter_};
void RestoreState(const IndexAndPositionState& saved_state) {
index_ = saved_state.index_;
current_ = saved_state.position_;
iteration_filter_ = saved_state.iteration_filter_;
function_entry_filter_ = saved_state.function_entry_filter_;
// Initializes the source position interator with the first valid bytecode.
// Also sets the FunctionEntry SourcePosition if it exists.
void Initialize();
static const int kDone = -1;
Vector<const byte> raw_table_;
Handle<ByteArray> table_;
int index_ = 0;
PositionTableEntry current_;
IterationFilter iteration_filter_;
FunctionEntryFilter function_entry_filter_;
} // namespace internal
} // namespace v8