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