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 #ifndef V8_INTERPRETER_HANDLER_TABLE_BUILDER_H_ 6 #define V8_INTERPRETER_HANDLER_TABLE_BUILDER_H_ 7 8 #include "src/frames.h" 9 #include "src/interpreter/bytecode-register.h" 10 #include "src/interpreter/bytecodes.h" 11 #include "src/zone/zone-containers.h" 12 13 namespace v8 { 14 namespace internal { 15 16 template <typename T> 17 class Handle; 18 class HandlerTable; 19 class Isolate; 20 21 namespace interpreter { 22 23 // A helper class for constructing exception handler tables for the interpreter. 24 class V8_EXPORT_PRIVATE HandlerTableBuilder final BASE_EMBEDDED { 25 public: 26 explicit HandlerTableBuilder(Zone* zone); 27 28 // Builds the actual handler table by copying the current values into a heap 29 // object. Any further mutations to the builder won't be reflected. 30 Handle<ByteArray> ToHandlerTable(Isolate* isolate); 31 32 // Creates a new handler table entry and returns a {hander_id} identifying the 33 // entry, so that it can be referenced by below setter functions. 34 int NewHandlerEntry(); 35 36 // Setter functions that modify certain values within the handler table entry 37 // being referenced by the given {handler_id}. All values will be encoded by 38 // the resulting {HandlerTable} class when copied into the heap. 39 void SetTryRegionStart(int handler_id, size_t offset); 40 void SetTryRegionEnd(int handler_id, size_t offset); 41 void SetHandlerTarget(int handler_id, size_t offset); 42 void SetPrediction(int handler_id, HandlerTable::CatchPrediction prediction); 43 void SetContextRegister(int handler_id, Register reg); 44 45 private: 46 struct Entry { 47 size_t offset_start; // Bytecode offset starting try-region. 48 size_t offset_end; // Bytecode offset ending try-region. 49 size_t offset_target; // Bytecode offset of handler target. 50 Register context; // Register holding context for handler. 51 // Optimistic prediction for handler. 52 HandlerTable::CatchPrediction catch_prediction_; 53 }; 54 55 ZoneVector<Entry> entries_; 56 57 DISALLOW_COPY_AND_ASSIGN(HandlerTableBuilder); 58 }; 59 60 } // namespace interpreter 61 } // namespace internal 62 } // namespace v8 63 64 #endif // V8_INTERPRETER_HANDLER_TABLE_BUILDER_H_ 65