/*

* Copyright 2021 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.

*/

#include "ir/module-utils.h"

#include "pass.h"

#include "wasm.h"

//

// Ensures each type has a name. This can be useful for debugging.

//

namespace wasm {

// An arbitrary limit, above which we rename types.

static const size_t NameLenLimit = 20;

struct NameTypes : public Pass {

bool requiresNonNullableLocalFixups() override { return false; }

void run(Module* module) override {

// Find all the types.

std::vector<HeapType> types = ModuleUtils::collectHeapTypes(*module);

std::unordered_set<Name> used;

// Ensure simple names. If a name already exists, and is short enough, keep

// it.

size_t i = 0;

for (auto& type : types) {

if (!module->typeNames.contains(type) ||

module->typeNames[type].name.size() >= NameLenLimit) {

module->typeNames[type].name = "type_" + std::to_string(i++);

}

used.insert(module->typeNames[type].name);

}

// "Lint" the names a little. In particular a name with a "_7" or such

// suffix, as TypeSSA creates, can be removed if it does not cause a

// collision. This keeps the names unique while removing 'noise.'

//

// Note we must iterate in a deterministic order here, so do it on |types|.

for (auto& type : types) {

auto& names = module->typeNames[type];

std::string name = names.name.toString();

while (name.size() > 1 && isdigit(name.back())) {

name.pop_back();

}

if (name.size() > 1 && name.back() == '_') {

name.pop_back();

if (!used.contains(name)) {

names.name = name;

used.insert(name);

}

}

}

}

};

Pass* createNameTypesPass() { return new NameTypes(); }

} // namespace wasm