Type.h

/*
 * 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.
 */

#ifndef TYPE_H_

#define TYPE_H_

#include <android-base/macros.h>
#include <utils/Errors.h>
#include <set>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <vector>

#include "DocComment.h"
#include "Reference.h"

namespace android {

struct ConstantExpression;
struct Formatter;
struct FQName;
struct ScalarType;
struct Scope;

struct Type : DocCommentable {
    Type(Scope* parent, const std::string& definedName);
    virtual ~Type();

    virtual bool isArray() const;
    virtual bool isBitField() const;
    virtual bool isCompoundType() const;
    virtual bool isEnum() const;
    virtual bool isHandle() const;
    virtual bool isInterface() const;
    virtual bool isNamedType() const;
    virtual bool isMemory() const;
    virtual bool isPointer() const;
    virtual bool isScope() const;
    virtual bool isScalar() const;
    virtual bool isString() const;
    virtual bool isTemplatedType() const;
    virtual bool isTypeDef() const;
    virtual bool isVector() const;
    virtual bool isFmq() const;

    // Resolves the type by unwrapping typedefs
    Type* resolve();
    virtual const Type* resolve() const;

    // All types defined in this type.
    std::vector<Type*> getDefinedTypes();
    virtual std::vector<const Type*> getDefinedTypes() const;

    // All types referenced in this type.
    std::vector<Reference<Type>*> getReferences();
    virtual std::vector<const Reference<Type>*> getReferences() const;

    // All constant expressions referenced in this type.
    std::vector<ConstantExpression*> getConstantExpressions();
    virtual std::vector<const ConstantExpression*> getConstantExpressions() const;

    // All types referenced in this type that must have completed
    // definiton before being referenced.
    std::vector<Reference<Type>*> getStrongReferences();
    virtual std::vector<const Reference<Type>*> getStrongReferences() const;

    // Indicate stage of parsing.
    enum class ParseStage {
        // Indicate that the source file is being parsed and this object is being filled.
        PARSE,
        // Indicate that all source files are parsed, and program is working on type dependencies
        // and validation.
        POST_PARSE,
        // Indicate that parsing is completed, and program is in code-generation stage.
        COMPLETED,
    };

    // Proceeds recursive pass
    // Makes sure to visit each node only once.
    // If mParseStage < stage, object is not ready for this recursivePass() call
    // yet, and function will return error.
    status_t recursivePass(ParseStage stage, const std::function<status_t(Type*)>& func,
                           std::unordered_set<const Type*>* visited);
    status_t recursivePass(ParseStage stage, const std::function<status_t(const Type*)>& func,
                           std::unordered_set<const Type*>* visited) const;

    // Recursive tree pass that completes type declarations
    // that depend on super types
    virtual status_t resolveInheritance();

    // Recursive tree pass that validates all type-related
    // syntax restrictions
    virtual status_t validate() const;

    // Recursive tree pass checkAcyclic return type.
    // Stores cycle end for nice error messages.
    struct CheckAcyclicStatus {
        CheckAcyclicStatus(status_t status, const Type* cycleEnd = nullptr);

        status_t status;

        // If a cycle is found, stores the end of cycle.
        // While going back in recursion, this is used to stop printing the cycle.
        const Type* cycleEnd;
    };

    // Recursive tree pass that ensures that type definitions and references
    // are acyclic and builds reversed topological order of the types.
    // If some cases allow using of incomplete types, these cases are to be
    // declared in Type::getStrongReferences.
    CheckAcyclicStatus topologicalOrder(std::unordered_map<const Type*, size_t>* reversedOrder,
                                        std::unordered_set<const Type*>* stack) const;

    // Checks following C++ restriction on forward declaration:
    // inner struct could be forward declared only inside its parent.
    status_t checkForwardReferenceRestrictions(const Reference<Type>& ref) const;

    virtual const ScalarType *resolveToScalarType() const;

    virtual std::string typeName() const = 0;

    bool isValidEnumStorageType() const;
    virtual bool isElidableType() const;

    virtual bool canCheckEquality() const;
    bool canCheckEquality(std::unordered_set<const Type*>* visited) const;
    virtual bool deepCanCheckEquality(std::unordered_set<const Type*>* visited) const;

    // ParseStage can only be incremented.
    ParseStage getParseStage() const;
    void setParseStage(ParseStage stage);

    Scope* parent();
    const Scope* parent() const;

    const std::string& definedName() const;

    enum StorageMode {
        StorageMode_Stack,
        StorageMode_Argument,
        StorageMode_Result,
    };

    // specifyNamespaces: whether to specify namespaces for built-in types
    virtual std::string getCppType(
            StorageMode mode,
            bool specifyNamespaces) const;

    std::string decorateCppName(
            const std::string &name,
            StorageMode mode,
            bool specifyNamespaces) const;

    std::string getCppStackType(bool specifyNamespaces = true) const;

    std::string getCppResultType(bool specifyNamespaces = true) const;

    std::string getCppArgumentType(bool specifyNamespaces = true) const;

    std::string getCppTypeCast(const std::string& objName,
                               bool specifyNamespaces = true) const;

    // For an array type, dimensionality information will be accumulated at the
    // end of the returned string.
    // if forInitializer == true, actual dimensions are included, i.e. [3][5],
    // otherwise (and by default), they are omitted, i.e. [][].
    virtual std::string getJavaType(bool forInitializer = false) const;

    // Identical to getJavaType() for most types, except: primitives, in which
    // case the wrapper type is returned, and generics (such as ArrayList<?>),
    // where the type specialization is omitted to facilitate use of
    // instanceof or class.isInstance().
    virtual std::string getJavaTypeClass() const;

    virtual std::string getJavaTypeCast(const std::string& objName) const;
    virtual std::string getJavaSuffix() const;

    virtual std::string getVtsType() const;
    virtual std::string getVtsValueName() const;

    enum ErrorMode {
        ErrorMode_Goto,
        ErrorMode_Break,
        ErrorMode_Return,
        ErrorMode_ReturnNothing,
    };
    virtual void emitReaderWriter(
            Formatter &out,
            const std::string &name,
            const std::string &parcelObj,
            bool parcelObjIsPointer,
            bool isReader,
            ErrorMode mode) const;

    virtual void 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;

    virtual void emitDump(
            Formatter &out,
            const std::string &streamName,
            const std::string &name) const;

    virtual void emitJavaDump(
            Formatter &out,
            const std::string &streamName,
            const std::string &name) const;

    virtual void emitJavaReaderWriter(
            Formatter &out,
            const std::string &parcelObj,
            const std::string &argName,
            bool isReader) const;

    virtual void emitJavaFieldInitializer(
            Formatter &out,
            const std::string &fieldName) const;

    virtual void emitJavaFieldDefaultInitialValue(
            Formatter &out,
            const std::string &declaredFieldName) const;

    virtual void 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;

    virtual void emitHidlDefinition(Formatter& out) const;

    virtual void emitTypeDeclarations(Formatter& out) const;

    virtual void emitGlobalTypeDeclarations(Formatter& out) const;

    // Emit scope C++ forward declaration.
    // There is no need to forward declare interfaces, as
    // they are always declared in global scope in dedicated file.
    virtual void emitTypeForwardDeclaration(Formatter& out) const;

    // Emit any declarations pertaining to this type that have to be
    // directly in a namespace, i.e. enum class operators.
    // For android.hardware.foo@1.0::*, this will be in namespace
    // android::hardware::foo::V1_0
    virtual void emitPackageTypeDeclarations(Formatter& out) const;

    // Emit any definitions pertaining to this type that have to be
    // directly in a namespace. Typically, these are things that are only
    // used for a small subset of types, so by putting them in the header,
    // the space cost is moved to the small number of clients that use the
    // feature.
    // For android.hardware.foo@1.0::*, this will be in namespace
    // android::hardware::foo::V1_0
    virtual void emitPackageTypeHeaderDefinitions(Formatter& out) const;

    // Emit any declarations pertaining to this type that have to be
    // at global scope for transport, e.g. read/writeEmbeddedTo/FromParcel
    // For android.hardware.foo@1.0::*, this will be in namespace
    // android::hardware::foo::V1_0
    virtual void emitPackageHwDeclarations(Formatter& out) const;

    virtual void emitTypeDefinitions(Formatter& out, const std::string& prefix) const;

    virtual void emitJavaTypeDeclarations(Formatter& out, bool atTopLevel) const;

    virtual bool needsEmbeddedReadWrite() const;
    virtual bool resultNeedsDeref() const;

    // Generates type declaration for vts proto file.
    // TODO (b/30844146): make it a pure virtual method.
    virtual void emitVtsTypeDeclarations(Formatter& out) const;
    // Generates type declaration as attribute of method (return value or method
    // argument) or attribute of compound type for vts proto file.
    virtual void emitVtsAttributeType(Formatter& out) const;

    // Returns true iff this type is supported through the Java backend.
    bool isJavaCompatible() const;
    bool isJavaCompatible(std::unordered_set<const Type*>* visited) const;
    virtual bool deepIsJavaCompatible(std::unordered_set<const Type*>* visited) const;
    // Returns true iff type contains pointer
    // (excluding methods and inner types).
    bool containsPointer() const;
    bool containsPointer(std::unordered_set<const Type*>* visited) const;
    virtual bool deepContainsPointer(std::unordered_set<const Type*>* visited) const;

    virtual void getAlignmentAndSize(size_t *align, size_t *size) const;

    virtual void appendToExportedTypesVector(
            std::vector<const Type *> *exportedTypes) const;

    virtual void emitExportedHeader(Formatter& out, bool forJava) const;

    virtual bool isNeverStrongReference() const;

    static void handleError(Formatter &out, ErrorMode mode);
   protected:
    void emitReaderWriterEmbeddedForTypeName(
            Formatter &out,
            const std::string &name,
            bool nameIsPointer,
            const std::string &parcelObj,
            bool parcelObjIsPointer,
            bool isReader,
            ErrorMode mode,
            const std::string &parentName,
            const std::string &offsetText,
            const std::string &typeName,
            const std::string &childName,
            const std::string &funcNamespace) const;

    void emitJavaReaderWriterWithSuffix(
            Formatter &out,
            const std::string &parcelObj,
            const std::string &argName,
            bool isReader,
            const std::string &suffix,
            const std::string &extra) const;

    void emitDumpWithMethod(
            Formatter &out,
            const std::string &streamName,
            const std::string &methodName,
            const std::string &name) const;

    // This is the name given to the type in the hidl file
    std::string mDefinedName;

  private:
    ParseStage mParseStage = ParseStage::PARSE;
    Scope* const mParent;

    DISALLOW_COPY_AND_ASSIGN(Type);
};

struct TemplatedType : public Type {
    void setElementType(const Reference<Type>& elementType);
    const Type* getElementType() const;

    virtual std::string templatedTypeName() const = 0;
    std::string typeName() const override;

    bool isTemplatedType() const override;

    virtual bool isCompatibleElementType(const Type* elementType) const = 0;

    std::vector<const Reference<Type>*> getReferences() const override;

    virtual status_t validate() const override;

    void emitVtsTypeDeclarations(Formatter& out) const override;
    void emitVtsAttributeType(Formatter& out) const override;

   protected:
     TemplatedType(Scope* parent, const std::string& definedName);
     Reference<Type> mElementType;

   private:
    DISALLOW_COPY_AND_ASSIGN(TemplatedType);
};

}  // namespace android

#endif  // TYPE_H_