system/tools/hidl/HandleType.cpp

/*
 * Copyright (C) 2016 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 "HandleType.h"

#include "HidlTypeAssertion.h"

#include <hidl-util/Formatter.h>
#include <android-base/logging.h>

namespace android {

HandleType::HandleType(Scope* parent) : Type(parent, "handle") {}

bool HandleType::isHandle() const {
    return true;
}

std::string HandleType::typeName() const {
    return "handle";
}

std::string HandleType::getCppType(StorageMode mode,
                                   bool specifyNamespaces) const {
    const std::string base =
          std::string(specifyNamespaces ? "::android::hardware::" : "")
        + "hidl_handle";

    switch (mode) {
        case StorageMode_Stack:
            return base;

        case StorageMode_Argument:
            return "const " + base + "&";

        case StorageMode_Result:
            return base;
    }
}

std::string HandleType::getJavaType(bool /* forInitializer */) const {
    return "android.os.NativeHandle";
}

std::string HandleType::getJavaSuffix() const {
    return "NativeHandle";
}

std::string HandleType::getVtsType() const {
    return "TYPE_HANDLE";
}

void HandleType::emitReaderWriter(
        Formatter &out,
        const std::string &name,
        const std::string &parcelObj,
        bool parcelObjIsPointer,
        bool isReader,
        ErrorMode mode) const {
    const std::string parcelObjDeref =
        parcelObj + (parcelObjIsPointer ? "->" : ".");

    if (isReader) {
        out << "const native_handle_t *"
            << name << "_ptr;\n\n";

        out << "_hidl_err = "
            << parcelObjDeref
            << "readNullableNativeHandleNoDup("
            << "&" << name << "_ptr"
            << ");\n\n";

        handleError(out, mode);

        out << name << " = " << name << "_ptr;\n";
    } else {
        out << "_hidl_err = ";
        out << parcelObjDeref
            << "writeNativeHandleNoDup("
            << name
            << ");\n";

        handleError(out, mode);
    }
}

void HandleType::emitReaderWriterEmbedded(
        Formatter &out,
        size_t /* depth */,
        const std::string &name,
        const std::string & /* sanitizedName */,
        bool nameIsPointer,
        const std::string &parcelObj,
        bool parcelObjIsPointer,
        bool isReader,
        ErrorMode mode,
        const std::string &parentName,
        const std::string &offsetText) const {
    emitReaderWriterEmbeddedForTypeName(
            out,
            name,
            nameIsPointer,
            parcelObj,
            parcelObjIsPointer,
            isReader,
            mode,
            parentName,
            offsetText,
            "::android::hardware::hidl_handle",
            "" /* childName */,
            "::android::hardware");
}

void HandleType::emitJavaFieldInitializer(
        Formatter &out, const std::string &fieldName) const {
    const std::string fieldDeclaration = getJavaType(false) + " " + fieldName;
    emitJavaFieldDefaultInitialValue(out, fieldDeclaration);
}

void HandleType::emitJavaFieldDefaultInitialValue(
        Formatter &out, const std::string &declaredFieldName) const {
    out << declaredFieldName
        << " = new "
        << getJavaType(true)
        << "();\n";
}

void HandleType::emitJavaFieldReaderWriter(
        Formatter &out,
        size_t /* depth */,
        const std::string &parcelName,
        const std::string &blobName,
        const std::string &fieldName,
        const std::string &offset,
        bool isReader) const {
    if (isReader) {
        out << fieldName
            << " = "
            << parcelName
            << ".readEmbeddedNativeHandle(\n";

        out.indent(2, [&] {
            out << blobName
                << ".handle(),\n"
                << offset
                << " + 0 /* offsetof(hidl_handle, mHandle) */);\n\n";
        });

        return;
    }

    out << blobName
        << ".putNativeHandle("
        << offset
        << ", "
        << fieldName
        << ");\n";
}

bool HandleType::needsEmbeddedReadWrite() const {
    return true;
}

bool HandleType::deepIsJavaCompatible(std::unordered_set<const Type*>* /* visited */) const {
    return true;
}

static HidlTypeAssertion assertion("hidl_handle", 16 /* size */);
void HandleType::getAlignmentAndSize(size_t *align, size_t *size) const {
    *align = 8;  // hidl_handle
    *size = assertion.size();
}

void HandleType::emitVtsTypeDeclarations(Formatter& out) const {
    out << "type: " << getVtsType() << "\n";
}

}  // namespace android