Line data    Source code

       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/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     1381546 : 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     1380184 :   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.
      35      260301 :   void Freeze() { frozen_ = true; }
      36             : 
      37             :  private:
      38             :   bool frozen_ = false;
      39             :   std::unordered_map<FunctionSig, uint32_t, base::hash<FunctionSig>> map_;
      40             : };
      41             : 
      42             : }  // namespace wasm
      43             : }  // namespace internal
      44             : }  // namespace v8
      45             : 
      46             : #endif  // V8_WASM_SIGNATURE_MAP_H_