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_WASM_SIGNATURE_MAP_H_ 6 #define V8_WASM_SIGNATURE_MAP_H_ 7 8 #include <unordered_map> 9 10 #include "src/codegen/signature.h" 11 #include "src/wasm/value-type.h" 12 13 namespace v8 { 14 namespace internal { 15 16 namespace wasm { 17 18 // A signature map canonicalizes signatures into a range of indices so that 19 // two different {FunctionSig} instances with the same contents map to the 20 // same index. 21 class V8_EXPORT_PRIVATE SignatureMap { 22 public: 23 // Allow default construction and move construction (because we have vectors 24 // of objects containing SignatureMaps), but disallow copy or assign. It's 25 // too easy to get security bugs by accidentally updating a copy of the map. 26 MOVE_ONLY_WITH_DEFAULT_CONSTRUCTORS(SignatureMap); 27 28 // Gets the index for a signature, assigning a new index if necessary. 29 uint32_t FindOrInsert(const FunctionSig& sig); 30 31 // Gets the index for a signature, returning {-1} if not found. 32 int32_t Find(const FunctionSig& sig) const; 33 34 // Disallows further insertions to this signature map. Freeze()35 void Freeze() { frozen_ = true; } 36 size()37 size_t size() const { return map_.size(); } 38 is_frozen()39 bool is_frozen() const { return frozen_; } 40 41 private: 42 bool frozen_ = false; 43 std::unordered_map<FunctionSig, uint32_t, base::hash<FunctionSig>> map_; 44 }; 45 46 } // namespace wasm 47 } // namespace internal 48 } // namespace v8 49 50 #endif // V8_WASM_SIGNATURE_MAP_H_ 51