tor-browser

WasmBuiltinModule.h (5719B)

---

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* vim: set ts=8 sts=2 et sw=2 tw=80:
*
* Copyright 2021 Mozilla Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
*     http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/

#ifndef wasm_builtin_module_h
#define wasm_builtin_module_h

#include "mozilla/EnumeratedArray.h"
#include "mozilla/Maybe.h"
#include "mozilla/Span.h"

#include "wasm/WasmBuiltins.h"
#include "wasm/WasmCompileArgs.h"
#include "wasm/WasmConstants.h"
#include "wasm/WasmSerialize.h"
#include "wasm/WasmTypeDecls.h"
#include "wasm/WasmTypeDef.h"

namespace js {
namespace wasm {

struct ImportValues;
struct Import;

struct MOZ_STACK_CLASS BuiltinModuleInstances {
 explicit BuiltinModuleInstances(JSContext* cx)
     : selfTest(cx), intGemm(cx), jsString(cx) {}

 Rooted<JSObject*> selfTest;
 Rooted<JSObject*> intGemm;
 Rooted<JSObject*> jsString;

 MutableHandle<JSObject*> operator[](BuiltinModuleId module) {
   switch (module) {
     case BuiltinModuleId::SelfTest: {
       return &selfTest;
     }
     case BuiltinModuleId::IntGemm: {
       return &intGemm;
     }
     case BuiltinModuleId::JSString: {
       return &jsString;
     }
     default: {
       MOZ_CRASH();
     }
   }
 }
};

// An builtin module func is a natively implemented function that may be
// compiled into a 'builtin module', which may be instantiated with a provided
// memory yielding an exported WebAssembly function wrapping the builtin module.
class BuiltinModuleFunc {
private:
 SharedRecGroup recGroup_;
 const char* exportName_;
 const SymbolicAddressSignature* sig_;
 bool usesMemory_;
 BuiltinInlineOp inlineOp_;

public:
 // Default constructor so this can be used in an EnumeratedArray.
 BuiltinModuleFunc() = default;

 // Initialize this builtin. Must only be called once.
 [[nodiscard]] bool init(const RefPtr<TypeContext>& types,
                         mozilla::Span<const ValType> params,
                         mozilla::Maybe<ValType> result, bool usesMemory,
                         const SymbolicAddressSignature* sig,
                         BuiltinInlineOp inlineOp, const char* exportName);

 // The rec group for the function type for this builtin.
 const RecGroup* recGroup() const { return recGroup_.get(); }
 // The type definition for the function type for this builtin.
 const TypeDef* typeDef() const { return &recGroup_->type(0); }
 // The function type for this builtin.
 const FuncType* funcType() const { return &typeDef()->funcType(); }

 // The name of the func as it is exported
 const char* exportName() const { return exportName_; }
 // The signature of the builtin that implements this function.
 const SymbolicAddressSignature* sig() const { return sig_; }
 // Whether this function takes a pointer to the memory base as a hidden final
 // parameter. This parameter will show up in the SymbolicAddressSignature,
 // but not the function type. Compilers must pass the memoryBase to the
 // function call as the last parameter.
 bool usesMemory() const { return usesMemory_; }
 // An optional inline operation that can be used for this function instead of
 // calling `sig`.
 BuiltinInlineOp inlineOp() const { return inlineOp_; }
};

// Static storage for all builtin module funcs in the system.
class BuiltinModuleFuncs {
 using Storage =
     mozilla::EnumeratedArray<BuiltinModuleFuncId, BuiltinModuleFunc,
                              size_t(BuiltinModuleFuncId::Limit)>;
 Storage funcs_;

 static BuiltinModuleFuncs* singleton_;

public:
 [[nodiscard]] static bool init();
 static void destroy();

 // Get the BuiltinModuleFunc for an BuiltinModuleFuncId. BuiltinModuleFuncId
 // must be validated.
 static const BuiltinModuleFunc& getFromId(BuiltinModuleFuncId id) {
   return singleton_->funcs_[id];
 }
};

mozilla::Maybe<BuiltinModuleId> ImportMatchesBuiltinModule(
   mozilla::Span<const char> importName,
   const BuiltinModuleIds& enabledBuiltins);
bool ImportMatchesBuiltinModuleFunc(mozilla::Span<const char> importName,
                                   BuiltinModuleId module,
                                   const BuiltinModuleFunc** matchedFunc,
                                   BuiltinModuleFuncId* matchedFuncId);

// Compile and return the builtin module for a particular
// builtin module. The `moduleMemoryImport` can be used if the builtin module
// requires memory to set the import name that it will need when it is
// instantiated, otherwise ("" "memory") is used instead.
[[nodiscard]] bool CompileBuiltinModule(
   JSContext* cx, BuiltinModuleId module, const Import* moduleMemoryImport,
   MutableHandle<WasmModuleObject*> result);

// Compile, instantiate and return the builtin module instance for a particular
// builtin module.
[[nodiscard]] bool InstantiateBuiltinModule(JSContext* cx,
                                           BuiltinModuleId module,
                                           const Import* moduleMemoryImport,
                                           Handle<JSObject*> importObj,
                                           MutableHandle<JSObject*> result);

}  // namespace wasm
}  // namespace js

#endif  // wasm_builtin_module_h