src/tools/execution-results.h - external/github.com/WebAssembly/binaryen - Git at Google

 /*
  * Copyright 2017 WebAssembly Community Group participants
  *
  * 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.
  */

 //
 // Shared execution result checking code
 //

 #include "shell-interface.h"
 #include "wasm.h"

 namespace wasm {

 using Loggings = std::vector<Literal>;

 // Logs every relevant import call parameter.
 struct LoggingExternalInterface : public ShellExternalInterface {
 private:
   Loggings& loggings;

   struct State {
     // Legalization for JS emits get/setTempRet0 calls ("temp ret 0" means a
     // temporary return value of 32 bits; "0" is the only important value for
     // 64-bit legalization, which needs one such 32-bit chunk in addition to
     // the normal return value which can handle 32 bits).
     uint32_t tempRet0 = 0;
   } state;

   // The name of the table exported by the name 'table.' Imports access it.
   Name exportedTable;
   Module& wasm;

   // The ModuleRunner and this ExternalInterface end up needing links both ways,
   // so we cannot init this in the constructor.
   ModuleRunner* instance = nullptr;

 public:
   LoggingExternalInterface(Loggings& loggings, Module& wasm)
     : loggings(loggings), wasm(wasm) {
     for (auto& exp : wasm.exports) {
       if (exp->kind == ExternalKind::Table && exp->name == "table") {
         exportedTable = exp->value;
         break;
       }
     }
   }

   Literals callImport(Function* import, const Literals& arguments) override {
     if (import->module == "fuzzing-support") {
       if (import->base.startsWith("log")) {
         // This is a logging function like log-i32 or log-f64
         std::cout << "[LoggingExternalInterface logging";
         loggings.push_back(Literal()); // buffer with a None between calls
         for (auto argument : arguments) {
           if (argument.type == Type::i64) {
             // To avoid JS legalization changing logging results, treat a
             // logging of an i64 as two i32s (which is what legalization would
             // turn us into).
             auto low = Literal(int32_t(argument.getInteger()));
             auto high = Literal(int32_t(argument.getInteger() >> int32_t(32)));
             std::cout << ' ' << low;
             loggings.push_back(low);
             std::cout << ' ' << high;
             loggings.push_back(high);
           } else {
             std::cout << ' ' << argument;
             loggings.push_back(argument);
           }
         }
         std::cout << "]\n";
         return {};
       } else if (import->base == "throw") {
         throwEmptyException();
       } else if (import->base == "table-get") {
         // Check for errors here, duplicating tableLoad(), because that will
         // trap, and we just want to throw an exception (the same as JS would).
         if (!exportedTable) {
           throwEmptyException();
         }
         auto index = arguments[0].getUnsigned();
         if (index >= tables[exportedTable].size()) {
           throwEmptyException();
         }
         return {tableLoad(exportedTable, index)};
       } else if (import->base == "table-set") {
         if (!exportedTable) {
           throwEmptyException();
         }
         auto index = arguments[0].getUnsigned();
         if (index >= tables[exportedTable].size()) {
           throwEmptyException();
         }
         tableStore(exportedTable, index, arguments[1]);
         return {};
       } else if (import->base == "call-export") {
         callExportAsJS(arguments[0].geti32());
         // Return nothing. If we wanted to return a value we'd need to have
         // multiple such functions, one for each signature.
         return {};
       } else if (import->base == "call-export-catch") {
         try {
           callExportAsJS(arguments[0].geti32());
           return {Literal(int32_t(0))};
         } catch (const WasmException& e) {
           return {Literal(int32_t(1))};
         }
       } else if (import->base == "call-ref") {
         callRefAsJS(arguments[0]);
         // Return nothing. If we wanted to return a value we'd need to have
         // multiple such functions, one for each signature.
         return {};
       } else if (import->base == "call-ref-catch") {
         try {
           callRefAsJS(arguments[0]);
           return {Literal(int32_t(0))};
         } catch (const WasmException& e) {
           return {Literal(int32_t(1))};
         }
       } else if (import->base == "sleep") {
         // Do not actually sleep, just return the id.
         return {arguments[1]};
       } else {
         WASM_UNREACHABLE("unknown fuzzer import");
       }
     } else if (import->module == ENV) {
       if (import->base == "log_execution") {
         std::cout << "[LoggingExternalInterface log-execution";
         for (auto argument : arguments) {
           std::cout << ' ' << argument;
         }
         std::cout << "]\n";
         return {};
       } else if (import->base == "setTempRet0") {
         state.tempRet0 = arguments[0].geti32();
         return {};
       } else if (import->base == "getTempRet0") {
         return {Literal(state.tempRet0)};
       }
     }
     std::cerr << "[LoggingExternalInterface ignoring an unknown import "
               << import->module << " . " << import->base << '\n';
     return {};
   }

   void throwEmptyException() {
     // Use a hopefully private tag.
     auto payload = std::make_shared<ExnData>("__private", Literals{});
     throwException(WasmException{Literal(payload)});
   }

   Literals callExportAsJS(Index index) {
     if (index >= wasm.exports.size()) {
       // No export.
       throwEmptyException();
     }
     auto& exp = wasm.exports[index];
     if (exp->kind != ExternalKind::Function) {
       // No callable export.
       throwEmptyException();
     }
     return callFunctionAsJS(exp->value);
   }

   Literals callRefAsJS(Literal ref) {
     if (!ref.isFunction()) {
       // Not a callable ref.
       throwEmptyException();
     }
     return callFunctionAsJS(ref.getFunc());
   }

   // Call a function in a "JS-ey" manner, adding arguments as needed, and
   // throwing if necessary, the same way JS does.
   Literals callFunctionAsJS(Name name) {
     auto* func = wasm.getFunction(name);

     // Send default values as arguments, or error if we need anything else.
     Literals arguments;
     for (const auto& param : func->getParams()) {
       // An i64 param can work from JS, but fuzz_shell provides 0, which errors
       // on attempts to convert it to BigInt. v128 and exnref are disalloewd.
       if (param == Type::i64 || param == Type::v128 || param.isExn()) {
         throwEmptyException();
       }
       if (!param.isDefaultable()) {
         throwEmptyException();
       }
       arguments.push_back(Literal::makeZero(param));
     }

     // Error on illegal results. Note that this happens, as per JS semantics,
     // *before* the call.
     for (const auto& result : func->getResults()) {
       // An i64 result is fine: a BigInt will be provided. But v128 and exnref
       // still error.
       if (result == Type::v128 || result.isExn()) {
         throwEmptyException();
       }
     }

     // Call the function.
     return instance->callFunction(func->name, arguments);
   }

   void setModuleRunner(ModuleRunner* instance_) { instance = instance_; }
 };

 // gets execution results from a wasm module. this is useful for fuzzing
 //
 // we can only get results when there are no imports. we then call each method
 // that has a result, with some values
 struct ExecutionResults {
   struct Trap {};
   struct Exception {};
   using FunctionResult = std::variant<Literals, Trap, Exception>;
   std::map<Name, FunctionResult> results;
   Loggings loggings;

   // If set, we should ignore this and not compare it to anything.
   bool ignore = false;

   // get results of execution
   void get(Module& wasm) {
     LoggingExternalInterface interface(loggings, wasm);
     try {
       ModuleRunner instance(wasm, &interface);
       interface.setModuleRunner(&instance);
       // execute all exported methods (that are therefore preserved through
       // opts)
       for (auto& exp : wasm.exports) {
         if (exp->kind != ExternalKind::Function) {
           continue;
         }
         std::cout << "[fuzz-exec] calling " << exp->name << "\n";
         auto* func = wasm.getFunction(exp->value);
         FunctionResult ret = run(func, wasm, instance);
         results[exp->name] = ret;
         if (auto* values = std::get_if<Literals>(&ret)) {
           // ignore the result if we hit an unreachable and returned no value
           if (values->size() > 0) {
             std::cout << "[fuzz-exec] note result: " << exp->name << " => ";
             for (auto value : *values) {
               printValue(value);
             }
           }
         }
       }
     } catch (const TrapException&) {
       // May throw in instance creation (init of offsets).
     } catch (const HostLimitException&) {
       // May throw in instance creation (e.g. array.new of huge size).
       // This should be ignored and not compared with, as optimizations can
       // change whether a host limit is reached.
       ignore = true;
     }
   }

   void printValue(Literal value) {
     // Unwrap an externalized value to get the actual value.
     if (Type::isSubType(value.type, Type(HeapType::ext, Nullable))) {
       value = value.internalize();
     }

     // Don't print most reference values, as e.g. funcref(N) contains an index,
     // which is not guaranteed to remain identical after optimizations. Do not
     // print the type in detail (as even that may change due to closed-world
     // optimizations); just print a simple type like JS does, 'object' or
     // 'function', but also print null for a null (so a null function does not
     // get printed as object, as in JS we have typeof null == 'object').
     //
     // The only references we print in full are strings and i31s, which have
     // simple and stable internal structures that optimizations will not alter.
     auto type = value.type;
     if (type.isRef()) {
       if (type.isString() || type.getHeapType().isMaybeShared(HeapType::i31)) {
         std::cout << value << '\n';
       } else if (value.isNull()) {
         std::cout << "null\n";
       } else if (type.isFunction()) {
         std::cout << "function\n";
       } else {
         std::cout << "object\n";
       }
       return;
     }

     // Non-references can be printed in full.
     std::cout << value << '\n';
   }

   // get current results and check them against previous ones
   void check(Module& wasm) {
     ExecutionResults optimizedResults;
     optimizedResults.get(wasm);
     if (optimizedResults != *this) {
       std::cout << "[fuzz-exec] optimization passes changed results\n";
       exit(1);
     }
   }

   bool areEqual(Literal a, Literal b) {
     // Don't compare references. There are several issues here that we can't
     // fully handle, see https://github.com/WebAssembly/binaryen/issues/3378,
     // but the core issue is that since we optimize assuming a closed world, the
     // types and structure of GC data can arbitrarily change after
     // optimizations, even in ways that are externally visible from outside
     // the module.
     //
     // We can, however, compare strings as they refer to simple data that has a
     // consistent representation (the same reasons as why we can print them in
     // printValue(), above).
     //
     // TODO: Once we support optimizing under some form of open-world
     // assumption, we should be able to check that the types and/or structure of
     // GC data passed out of the module does not change.
     if (a.type.isRef() && !a.type.isString() &&
         !a.type.getHeapType().isMaybeShared(HeapType::i31)) {
       return true;
     }
     if (a != b) {
       std::cout << "values not identical! " << a << " != " << b << '\n';
       return false;
     }
     return true;
   }

   bool areEqual(Literals a, Literals b) {
     if (a.size() != b.size()) {
       std::cout << "literal counts not identical! " << a << " != " << b << '\n';
       return false;
     }
     for (Index i = 0; i < a.size(); i++) {
       if (!areEqual(a[i], b[i])) {
         return false;
       }
     }
     return true;
   }

   bool operator==(ExecutionResults& other) {
     if (ignore || other.ignore) {
       std::cout << "ignoring comparison of ExecutionResults!\n";
       return true;
     }
     for (auto& [name, _] : other.results) {
       if (results.find(name) == results.end()) {
         std::cout << "[fuzz-exec] missing " << name << '\n';
         return false;
       }
       std::cout << "[fuzz-exec] comparing " << name << '\n';
       if (results[name].index() != other.results[name].index()) {
         return false;
       }
       auto* values = std::get_if<Literals>(&results[name]);
       auto* otherValues = std::get_if<Literals>(&other.results[name]);
       if (values && otherValues && !areEqual(*values, *otherValues)) {
         return false;
       }
     }
     if (loggings.size() != other.loggings.size()) {
       std::cout << "logging counts not identical!\n";
       return false;
     }
     for (Index i = 0; i < loggings.size(); i++) {
       if (!areEqual(loggings[i], other.loggings[i])) {
         return false;
       }
     }
     return true;
   }

   bool operator!=(ExecutionResults& other) { return !((*this) == other); }

   FunctionResult run(Function* func, Module& wasm) {
     LoggingExternalInterface interface(loggings, wasm);
     try {
       ModuleRunner instance(wasm, &interface);
       interface.setModuleRunner(&instance);
       return run(func, wasm, instance);
     } catch (const TrapException&) {
       // May throw in instance creation (init of offsets).
       return {};
     } catch (const HostLimitException&) {
       // May throw in instance creation (e.g. array.new of huge size).
       // This should be ignored and not compared with, as optimizations can
       // change whether a host limit is reached.
       ignore = true;
       return {};
     }
   }

   FunctionResult run(Function* func, Module& wasm, ModuleRunner& instance) {
     try {
       // call the method
       Literals arguments;
       for (const auto& param : func->getParams()) {
         // zeros in arguments TODO: more?
         if (!param.isDefaultable()) {
           std::cout << "[trap fuzzer can only send defaultable parameters to "
                        "exports]\n";
           return Trap{};
         }
         arguments.push_back(Literal::makeZero(param));
       }
       return instance.callFunction(func->name, arguments);
     } catch (const TrapException&) {
       return Trap{};
     } catch (const WasmException& e) {
       std::cout << "[exception thrown: " << e << "]" << std::endl;
       return Exception{};
     } catch (const HostLimitException&) {
       // This should be ignored and not compared with, as optimizations can
       // change whether a host limit is reached.
       ignore = true;
       return {};
     }
   }
 };

 } // namespace wasm
	/*
	* Copyright 2017 WebAssembly Community Group participants
	*
	* 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.
	*/

	//
	// Shared execution result checking code
	//

	#include "shell-interface.h"
	#include "wasm.h"

	namespace wasm {

	using Loggings = std::vector<Literal>;

	// Logs every relevant import call parameter.
	struct LoggingExternalInterface : public ShellExternalInterface {
	private:
	Loggings& loggings;

	struct State {
	// Legalization for JS emits get/setTempRet0 calls ("temp ret 0" means a
	// temporary return value of 32 bits; "0" is the only important value for
	// 64-bit legalization, which needs one such 32-bit chunk in addition to
	// the normal return value which can handle 32 bits).
	uint32_t tempRet0 = 0;
	} state;

	// The name of the table exported by the name 'table.' Imports access it.
	Name exportedTable;
	Module& wasm;

	// The ModuleRunner and this ExternalInterface end up needing links both ways,
	// so we cannot init this in the constructor.
	ModuleRunner* instance = nullptr;

	public:
	LoggingExternalInterface(Loggings& loggings, Module& wasm)
	: loggings(loggings), wasm(wasm) {
	for (auto& exp : wasm.exports) {
	if (exp->kind == ExternalKind::Table && exp->name == "table") {
	exportedTable = exp->value;
	break;
	}
	}
	}

	Literals callImport(Function* import, const Literals& arguments) override {
	if (import->module == "fuzzing-support") {
	if (import->base.startsWith("log")) {
	// This is a logging function like log-i32 or log-f64
	std::cout << "[LoggingExternalInterface logging";
	loggings.push_back(Literal()); // buffer with a None between calls
	for (auto argument : arguments) {
	if (argument.type == Type::i64) {
	// To avoid JS legalization changing logging results, treat a
	// logging of an i64 as two i32s (which is what legalization would
	// turn us into).
	auto low = Literal(int32_t(argument.getInteger()));
	auto high = Literal(int32_t(argument.getInteger() >> int32_t(32)));
	std::cout << ' ' << low;
	loggings.push_back(low);
	std::cout << ' ' << high;
	loggings.push_back(high);
	} else {
	std::cout << ' ' << argument;
	loggings.push_back(argument);
	}
	}
	std::cout << "]\n";
	return {};
	} else if (import->base == "throw") {
	throwEmptyException();
	} else if (import->base == "table-get") {
	// Check for errors here, duplicating tableLoad(), because that will
	// trap, and we just want to throw an exception (the same as JS would).
	if (!exportedTable) {
	throwEmptyException();
	}
	auto index = arguments[0].getUnsigned();
	if (index >= tables[exportedTable].size()) {
	throwEmptyException();
	}
	return {tableLoad(exportedTable, index)};
	} else if (import->base == "table-set") {
	if (!exportedTable) {
	throwEmptyException();
	}
	auto index = arguments[0].getUnsigned();
	if (index >= tables[exportedTable].size()) {
	throwEmptyException();
	}
	tableStore(exportedTable, index, arguments[1]);
	return {};
	} else if (import->base == "call-export") {
	callExportAsJS(arguments[0].geti32());
	// Return nothing. If we wanted to return a value we'd need to have
	// multiple such functions, one for each signature.
	return {};
	} else if (import->base == "call-export-catch") {
	try {
	callExportAsJS(arguments[0].geti32());
	return {Literal(int32_t(0))};
	} catch (const WasmException& e) {
	return {Literal(int32_t(1))};
	}
	} else if (import->base == "call-ref") {
	callRefAsJS(arguments[0]);
	// Return nothing. If we wanted to return a value we'd need to have
	// multiple such functions, one for each signature.
	return {};
	} else if (import->base == "call-ref-catch") {
	try {
	callRefAsJS(arguments[0]);
	return {Literal(int32_t(0))};
	} catch (const WasmException& e) {
	return {Literal(int32_t(1))};
	}
	} else if (import->base == "sleep") {
	// Do not actually sleep, just return the id.
	return {arguments[1]};
	} else {
	WASM_UNREACHABLE("unknown fuzzer import");
	}
	} else if (import->module == ENV) {
	if (import->base == "log_execution") {
	std::cout << "[LoggingExternalInterface log-execution";
	for (auto argument : arguments) {
	std::cout << ' ' << argument;
	}
	std::cout << "]\n";
	return {};
	} else if (import->base == "setTempRet0") {
	state.tempRet0 = arguments[0].geti32();
	return {};
	} else if (import->base == "getTempRet0") {
	return {Literal(state.tempRet0)};
	}
	}
	std::cerr << "[LoggingExternalInterface ignoring an unknown import "
	<< import->module << " . " << import->base << '\n';
	return {};
	}

	void throwEmptyException() {
	// Use a hopefully private tag.
	auto payload = std::make_shared<ExnData>("__private", Literals{});
	throwException(WasmException{Literal(payload)});
	}

	Literals callExportAsJS(Index index) {
	if (index >= wasm.exports.size()) {
	// No export.
	throwEmptyException();
	}
	auto& exp = wasm.exports[index];
	if (exp->kind != ExternalKind::Function) {
	// No callable export.
	throwEmptyException();
	}
	return callFunctionAsJS(exp->value);
	}

	Literals callRefAsJS(Literal ref) {
	if (!ref.isFunction()) {
	// Not a callable ref.
	throwEmptyException();
	}
	return callFunctionAsJS(ref.getFunc());
	}

	// Call a function in a "JS-ey" manner, adding arguments as needed, and
	// throwing if necessary, the same way JS does.
	Literals callFunctionAsJS(Name name) {
	auto* func = wasm.getFunction(name);

	// Send default values as arguments, or error if we need anything else.
	Literals arguments;
	for (const auto& param : func->getParams()) {
	// An i64 param can work from JS, but fuzz_shell provides 0, which errors
	// on attempts to convert it to BigInt. v128 and exnref are disalloewd.
	if (param == Type::i64 \|\| param == Type::v128 \|\| param.isExn()) {
	throwEmptyException();
	}
	if (!param.isDefaultable()) {
	throwEmptyException();
	}
	arguments.push_back(Literal::makeZero(param));
	}

	// Error on illegal results. Note that this happens, as per JS semantics,
	// before the call.
	for (const auto& result : func->getResults()) {
	// An i64 result is fine: a BigInt will be provided. But v128 and exnref
	// still error.
	if (result == Type::v128 \|\| result.isExn()) {
	throwEmptyException();
	}
	}

	// Call the function.
	return instance->callFunction(func->name, arguments);
	}

	void setModuleRunner(ModuleRunner* instance_) { instance = instance_; }
	};

	// gets execution results from a wasm module. this is useful for fuzzing
	//
	// we can only get results when there are no imports. we then call each method
	// that has a result, with some values
	struct ExecutionResults {
	struct Trap {};
	struct Exception {};
	using FunctionResult = std::variant<Literals, Trap, Exception>;
	std::map<Name, FunctionResult> results;
	Loggings loggings;

	// If set, we should ignore this and not compare it to anything.
	bool ignore = false;

	// get results of execution
	void get(Module& wasm) {
	LoggingExternalInterface interface(loggings, wasm);
	try {
	ModuleRunner instance(wasm, &interface);
	interface.setModuleRunner(&instance);
	// execute all exported methods (that are therefore preserved through
	// opts)
	for (auto& exp : wasm.exports) {
	if (exp->kind != ExternalKind::Function) {
	continue;
	}
	std::cout << "[fuzz-exec] calling " << exp->name << "\n";
	auto* func = wasm.getFunction(exp->value);
	FunctionResult ret = run(func, wasm, instance);
	results[exp->name] = ret;
	if (auto* values = std::get_if<Literals>(&ret)) {
	// ignore the result if we hit an unreachable and returned no value
	if (values->size() > 0) {
	std::cout << "[fuzz-exec] note result: " << exp->name << " => ";
	for (auto value : *values) {
	printValue(value);
	}
	}
	}
	}
	} catch (const TrapException&) {
	// May throw in instance creation (init of offsets).
	} catch (const HostLimitException&) {
	// May throw in instance creation (e.g. array.new of huge size).
	// This should be ignored and not compared with, as optimizations can
	// change whether a host limit is reached.
	ignore = true;
	}
	}

	void printValue(Literal value) {
	// Unwrap an externalized value to get the actual value.
	if (Type::isSubType(value.type, Type(HeapType::ext, Nullable))) {
	value = value.internalize();
	}

	// Don't print most reference values, as e.g. funcref(N) contains an index,
	// which is not guaranteed to remain identical after optimizations. Do not
	// print the type in detail (as even that may change due to closed-world
	// optimizations); just print a simple type like JS does, 'object' or
	// 'function', but also print null for a null (so a null function does not
	// get printed as object, as in JS we have typeof null == 'object').
	//
	// The only references we print in full are strings and i31s, which have
	// simple and stable internal structures that optimizations will not alter.
	auto type = value.type;
	if (type.isRef()) {
	if (type.isString() \|\| type.getHeapType().isMaybeShared(HeapType::i31)) {
	std::cout << value << '\n';
	} else if (value.isNull()) {
	std::cout << "null\n";
	} else if (type.isFunction()) {
	std::cout << "function\n";
	} else {
	std::cout << "object\n";
	}
	return;
	}

	// Non-references can be printed in full.
	std::cout << value << '\n';
	}

	// get current results and check them against previous ones
	void check(Module& wasm) {
	ExecutionResults optimizedResults;
	optimizedResults.get(wasm);
	if (optimizedResults != *this) {
	std::cout << "[fuzz-exec] optimization passes changed results\n";
	exit(1);
	}
	}

	bool areEqual(Literal a, Literal b) {
	// Don't compare references. There are several issues here that we can't
	// fully handle, see https://github.com/WebAssembly/binaryen/issues/3378,
	// but the core issue is that since we optimize assuming a closed world, the
	// types and structure of GC data can arbitrarily change after
	// optimizations, even in ways that are externally visible from outside
	// the module.
	//
	// We can, however, compare strings as they refer to simple data that has a
	// consistent representation (the same reasons as why we can print them in
	// printValue(), above).
	//
	// TODO: Once we support optimizing under some form of open-world
	// assumption, we should be able to check that the types and/or structure of
	// GC data passed out of the module does not change.
	if (a.type.isRef() && !a.type.isString() &&
	!a.type.getHeapType().isMaybeShared(HeapType::i31)) {
	return true;
	}
	if (a != b) {
	std::cout << "values not identical! " << a << " != " << b << '\n';
	return false;
	}
	return true;
	}

	bool areEqual(Literals a, Literals b) {
	if (a.size() != b.size()) {
	std::cout << "literal counts not identical! " << a << " != " << b << '\n';
	return false;
	}
	for (Index i = 0; i < a.size(); i++) {
	if (!areEqual(a[i], b[i])) {
	return false;
	}
	}
	return true;
	}

	bool operator==(ExecutionResults& other) {
	if (ignore \|\| other.ignore) {
	std::cout << "ignoring comparison of ExecutionResults!\n";
	return true;
	}
	for (auto& [name, _] : other.results) {
	if (results.find(name) == results.end()) {
	std::cout << "[fuzz-exec] missing " << name << '\n';
	return false;
	}
	std::cout << "[fuzz-exec] comparing " << name << '\n';
	if (results[name].index() != other.results[name].index()) {
	return false;
	}
	auto* values = std::get_if<Literals>(&results[name]);
	auto* otherValues = std::get_if<Literals>(&other.results[name]);
	if (values && otherValues && !areEqual(values, otherValues)) {
	return false;
	}
	}
	if (loggings.size() != other.loggings.size()) {
	std::cout << "logging counts not identical!\n";
	return false;
	}
	for (Index i = 0; i < loggings.size(); i++) {
	if (!areEqual(loggings[i], other.loggings[i])) {
	return false;
	}
	}
	return true;
	}

	bool operator!=(ExecutionResults& other) { return !((*this) == other); }

	FunctionResult run(Function* func, Module& wasm) {
	LoggingExternalInterface interface(loggings, wasm);
	try {
	ModuleRunner instance(wasm, &interface);
	interface.setModuleRunner(&instance);
	return run(func, wasm, instance);
	} catch (const TrapException&) {
	// May throw in instance creation (init of offsets).
	return {};
	} catch (const HostLimitException&) {
	// May throw in instance creation (e.g. array.new of huge size).
	// This should be ignored and not compared with, as optimizations can
	// change whether a host limit is reached.
	ignore = true;
	return {};
	}
	}

	FunctionResult run(Function* func, Module& wasm, ModuleRunner& instance) {
	try {
	// call the method
	Literals arguments;
	for (const auto& param : func->getParams()) {
	// zeros in arguments TODO: more?
	if (!param.isDefaultable()) {
	std::cout << "[trap fuzzer can only send defaultable parameters to "
	"exports]\n";
	return Trap{};
	}
	arguments.push_back(Literal::makeZero(param));
	}
	return instance.callFunction(func->name, arguments);
	} catch (const TrapException&) {
	return Trap{};
	} catch (const WasmException& e) {
	std::cout << "[exception thrown: " << e << "]" << std::endl;
	return Exception{};
	} catch (const HostLimitException&) {
	// This should be ignored and not compared with, as optimizations can
	// change whether a host limit is reached.
	ignore = true;
	return {};
	}
	}
	};

	} // namespace wasm