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/*
* Copyright (C) 2019 The Android Open Source Project
*
* 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 <android-base/logging.h>
#include <unordered_set>
#include <vector>
#include "AST.h"
#include "CompoundType.h"
#include "Lint.h"
#include "LintRegistry.h"
#include "Location.h"
#include "Scope.h"
#include "Type.h"
namespace android {
// if this pattern of separate execution for getDefinedTypes and getReferences is common, it should
// be abstacted into a recursivePass type function
static void lintUnionRecursively(const Scope* scope, std::unordered_set<const Type*>* visited,
std::vector<Lint>* errors) {
CHECK(scope->getParseStage() == Type::ParseStage::COMPLETED)
<< "type parsing is not yet complete";
if (visited->find(scope) != visited->end()) return;
visited->insert(scope);
std::string lintExplanation =
"Union types should not be used since they are not supported in Java and are not type "
"safe. Prefer using safe_union instead.";
for (const auto* nextType : scope->getDefinedTypes()) {
if (!nextType->isCompoundType()) {
// if the type is not compound then it cannot be a union type, but can contain one.
lintUnionRecursively(static_cast<const Scope*>(nextType), visited, errors);
continue;
}
const CompoundType* compoundType = static_cast<const CompoundType*>(nextType);
if (compoundType->style() == CompoundType::Style::STYLE_UNION) {
errors->push_back(Lint(ERROR, compoundType->location())
<< compoundType->typeName() << " is defined as a Union type.\n"
<< lintExplanation << "\n");
continue;
}
// Not a union type, so must be struct or safe_union
// Definitely still in the same file.
lintUnionRecursively(compoundType, visited, errors);
}
for (const auto* nextRef : scope->getReferences()) {
if (!nextRef->get()->isCompoundType()) continue;
const CompoundType* compoundType = static_cast<const CompoundType*>(nextRef->get());
if (compoundType->style() == CompoundType::Style::STYLE_UNION) {
// The reference was not from this scope
if (!Location::inSameFile(scope->location(), nextRef->location())) continue;
// The type is defined in the same file. Will lint there.
if (Location::inSameFile(scope->location(), compoundType->location())) continue;
errors->push_back(Lint(ERROR, nextRef->location())
<< "Reference to union type: " << compoundType->typeName()
<< " located in " << compoundType->location().begin().filename()
<< "\n"
<< lintExplanation << "\n");
continue;
}
const status_t FOUND_UNION = 1;
status_t result = compoundType->recursivePass(
Type::ParseStage::COMPLETED,
[&](const Type* type) -> status_t {
if (!type->isCompoundType()) return OK;
const CompoundType* compoundType = static_cast<const CompoundType*>(type);
if (compoundType->style() == CompoundType::Style::STYLE_UNION) {
return FOUND_UNION;
}
// some other type of compound type, like struct/safeunion
return OK;
},
visited);
if (result == FOUND_UNION) {
// The struct contains a reference to a union somewhere
errors->push_back(Lint(ERROR, nextRef->location())
<< "Reference to struct: " << compoundType->typeName()
<< " located in " << compoundType->location().begin().filename()
<< " contains a union type.\n"
<< lintExplanation << "\n");
}
}
}
static void safeunionLint(const AST& ast, std::vector<Lint>* errors) {
// Should lint if it contains a union type at any level
std::unordered_set<const Type*> visited;
lintUnionRecursively(&ast.getRootScope(), &visited, errors);
}
REGISTER_LINT(safeunionLint);
} // namespace android