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/*
* Copyright 2016 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.
*/
//
// A WebAssembly optimizer, loads code, optionally runs passes on it,
// then writes it.
//
#include <memory>
#include "pass.h"
#include "support/command-line.h"
#include "support/file.h"
#include "wasm-printing.h"
#include "wasm-s-parser.h"
#include "wasm-validator.h"
#include "wasm-io.h"
#include "wasm-interpreter.h"
#include "shell-interface.h"
#include "optimization-options.h"
using namespace wasm;
// 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 {
std::map<Name, Literal> results;
void get(Module& wasm) {
if (wasm.imports.size() > 0) {
std::cout << "[fuzz-exec] imports, so quitting\n";
return;
}
for (auto& func : wasm.functions) {
if (func->result != none) {
// this is good
results[func->name] = run(func.get(), wasm);
}
}
std::cout << "[fuzz-exec] " << results.size() << " results noted\n";
}
bool operator==(ExecutionResults& other) {
for (auto& iter : results) {
auto name = iter.first;
if (other.results.find(name) != other.results.end()) {
if (results[name] != other.results[name]) {
return false;
}
}
}
return true;
}
bool operator!=(ExecutionResults& other) {
return !((*this) == other);
}
Literal run(Function* func, Module& wasm) {
ShellExternalInterface interface;
try {
ModuleInstance instance(wasm, &interface);
LiteralList arguments;
for (WasmType param : func->params) {
// zeros in arguments TODO: more?
arguments.push_back(Literal(param));
}
return instance.callFunction(func->name, arguments);
} catch (const TrapException&) {
// may throw in instance creation (init of offsets) or call itself
return Literal();
}
}
};
//
// main
//
int main(int argc, const char* argv[]) {
Name entry;
std::vector<std::string> passes;
bool emitBinary = true;
bool debugInfo = false;
bool fuzzExec = false;
OptimizationOptions options("wasm-opt", "Optimize .wast files");
options
.add("--output", "-o", "Output file (stdout if not specified)",
Options::Arguments::One,
[](Options* o, const std::string& argument) {
o->extra["output"] = argument;
Colors::disable();
})
.add("--emit-text", "-S", "Emit text instead of binary for the output file",
Options::Arguments::Zero,
[&](Options *o, const std::string &argument) { emitBinary = false; })
.add("--debuginfo", "-g", "Emit names section and debug info",
Options::Arguments::Zero,
[&](Options *o, const std::string &arguments) { debugInfo = true; })
.add("--fuzz-exec", "-fe", "Execute functions before and after optimization, helping fuzzing find bugs",
Options::Arguments::Zero,
[&](Options *o, const std::string &arguments) { fuzzExec = true; })
.add_positional("INFILE", Options::Arguments::One,
[](Options* o, const std::string& argument) {
o->extra["infile"] = argument;
});
options.parse(argc, argv);
auto input(read_file<std::string>(options.extra["infile"], Flags::Text, options.debug ? Flags::Debug : Flags::Release));
Module wasm;
{
if (options.debug) std::cerr << "reading...\n";
ModuleReader reader;
reader.setDebug(options.debug);
try {
reader.read(options.extra["infile"], wasm);
} catch (ParseException& p) {
p.dump(std::cerr);
Fatal() << "error in parsing input";
} catch (std::bad_alloc& b) {
Fatal() << "error in building module, std::bad_alloc (possibly invalid request for silly amounts of memory)";
}
}
if (!WasmValidator().validate(wasm)) {
Fatal() << "error in validating input";
}
ExecutionResults results;
if (fuzzExec) {
results.get(wasm);
}
if (options.runningPasses()) {
if (options.debug) std::cerr << "running passes...\n";
PassRunner passRunner = options.getPassRunner(wasm);
passRunner.run();
assert(WasmValidator().validate(wasm));
}
if (fuzzExec) {
ExecutionResults optimizedResults;
optimizedResults.get(wasm);
if (optimizedResults != results) {
Fatal() << "[fuzz-exec] optimization passes changed execution results";
}
std::cout << "[fuzz-exec] results match\n";
}
if (options.extra.count("output") > 0) {
if (options.debug) std::cerr << "writing..." << std::endl;
ModuleWriter writer;
writer.setDebug(options.debug);
writer.setBinary(emitBinary);
writer.setDebugInfo(debugInfo);
writer.write(wasm, options.extra["output"]);
}
}
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