//===--- MultiplexExternalSemaSource.h - External Sema Interface-*- C++ -*-===//

//

// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.

// See https://llvm.org/LICENSE.txt for license information.

// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

//

//===----------------------------------------------------------------------===//

//

//  This file defines ExternalSemaSource interface, dispatching to all clients

//

//===----------------------------------------------------------------------===//

#ifndef LLVM_CLANG_SEMA_MULTIPLEXEXTERNALSEMASOURCE_H

#define LLVM_CLANG_SEMA_MULTIPLEXEXTERNALSEMASOURCE_H

#include "clang/Sema/ExternalSemaSource.h"

#include "clang/Sema/Weak.h"

#include "llvm/ADT/SmallVector.h"

#include <utility>

namespace clang {

  class CXXConstructorDecl;

  class CXXRecordDecl;

  class DeclaratorDecl;

  struct ExternalVTableUse;

  class LookupResult;

  class NamespaceDecl;

  class Scope;

  class Sema;

  class TypedefNameDecl;

  class ValueDecl;

  class VarDecl;

/// An abstract interface that should be implemented by

/// external AST sources that also provide information for semantic

/// analysis.

class MultiplexExternalSemaSource : public ExternalSemaSource {

  /// LLVM-style RTTI.

  static char ID;

private:

  SmallVector<ExternalSemaSource *, 2> Sources; // doesn't own them.

public:

  ///Constructs a new multiplexing external sema source and appends the

  /// given element to it.

  ///

  ///\param[in] s1 - A non-null (old) ExternalSemaSource.

  ///\param[in] s2 - A non-null (new) ExternalSemaSource.

  ///

  MultiplexExternalSemaSource(ExternalSemaSource& s1, ExternalSemaSource& s2);

  ~MultiplexExternalSemaSource() override;

  ///Appends new source to the source list.

  ///

  ///\param[in] source - An ExternalSemaSource.

  ///

  void addSource(ExternalSemaSource &source);

  //===--------------------------------------------------------------------===//

  // ExternalASTSource.

  //===--------------------------------------------------------------------===//

  /// Resolve a declaration ID into a declaration, potentially

  /// building a new declaration.

  Decl *GetExternalDecl(uint32_t ID) override;

  /// Complete the redeclaration chain if it's been extended since the

  /// previous generation of the AST source.

  void CompleteRedeclChain(const Decl *D) override;

  /// Resolve a selector ID into a selector.

  Selector GetExternalSelector(uint32_t ID) override;

  /// Returns the number of selectors known to the external AST

  /// source.

  uint32_t GetNumExternalSelectors() override;

  /// Resolve the offset of a statement in the decl stream into

  /// a statement.

  Stmt *GetExternalDeclStmt(uint64_t Offset) override;

  /// Resolve the offset of a set of C++ base specifiers in the decl

  /// stream into an array of specifiers.

  CXXBaseSpecifier *GetExternalCXXBaseSpecifiers(uint64_t Offset) override;

  /// Resolve a handle to a list of ctor initializers into the list of

  /// initializers themselves.

  CXXCtorInitializer **GetExternalCXXCtorInitializers(uint64_t Offset) override;

  ExtKind hasExternalDefinitions(const Decl *D) override;

  /// Find all declarations with the given name in the

  /// given context.

  bool FindExternalVisibleDeclsByName(const DeclContext *DC,

                                      DeclarationName Name) override;

  /// Ensures that the table of all visible declarations inside this

  /// context is up to date.

  void completeVisibleDeclsMap(const DeclContext *DC) override;

  /// Finds all declarations lexically contained within the given

  /// DeclContext, after applying an optional filter predicate.

  ///

  /// \param IsKindWeWant a predicate function that returns true if the passed

  /// declaration kind is one we are looking for.

  void

  FindExternalLexicalDecls(const DeclContext *DC,

                           llvm::function_ref<bool(Decl::Kind)> IsKindWeWant,

                           SmallVectorImpl<Decl *> &Result) override;

  /// Get the decls that are contained in a file in the Offset/Length

  /// range. \p Length can be 0 to indicate a point at \p Offset instead of

  /// a range.

  void FindFileRegionDecls(FileID File, unsigned Offset,unsigned Length,

                           SmallVectorImpl<Decl *> &Decls) override;

  /// Gives the external AST source an opportunity to complete

  /// an incomplete type.

  void CompleteType(TagDecl *Tag) override;

  /// Gives the external AST source an opportunity to complete an

  /// incomplete Objective-C class.

  ///

  /// This routine will only be invoked if the "externally completed" bit is

  /// set on the ObjCInterfaceDecl via the function

  /// \c ObjCInterfaceDecl::setExternallyCompleted().

  void CompleteType(ObjCInterfaceDecl *Class) override;

  /// Loads comment ranges.

  void ReadComments() override;

  /// Notify ExternalASTSource that we started deserialization of

  /// a decl or type so until FinishedDeserializing is called there may be

  /// decls that are initializing. Must be paired with FinishedDeserializing.

  void StartedDeserializing() override;

  /// Notify ExternalASTSource that we finished the deserialization of

  /// a decl or type. Must be paired with StartedDeserializing.

  void FinishedDeserializing() override;

  /// Function that will be invoked when we begin parsing a new

  /// translation unit involving this external AST source.

  void StartTranslationUnit(ASTConsumer *Consumer) override;

  /// Print any statistics that have been gathered regarding

  /// the external AST source.

  void PrintStats() override;

  /// Retrieve the module that corresponds to the given module ID.

  Module *getModule(unsigned ID) override;

  /// Perform layout on the given record.

  ///

  /// This routine allows the external AST source to provide an specific

  /// layout for a record, overriding the layout that would normally be

  /// constructed. It is intended for clients who receive specific layout

  /// details rather than source code (such as LLDB). The client is expected

  /// to fill in the field offsets, base offsets, virtual base offsets, and

  /// complete object size.

  ///

  /// \param Record The record whose layout is being requested.

  ///

  /// \param Size The final size of the record, in bits.

  ///

  /// \param Alignment The final alignment of the record, in bits.

  ///

  /// \param FieldOffsets The offset of each of the fields within the record,

  /// expressed in bits. All of the fields must be provided with offsets.

  ///

  /// \param BaseOffsets The offset of each of the direct, non-virtual base

  /// classes. If any bases are not given offsets, the bases will be laid

  /// out according to the ABI.

  ///

  /// \param VirtualBaseOffsets The offset of each of the virtual base classes

  /// (either direct or not). If any bases are not given offsets, the bases will

  /// be laid out according to the ABI.

  ///

  /// \returns true if the record layout was provided, false otherwise.

  bool

  layoutRecordType(const RecordDecl *Record,

                   uint64_t &Size, uint64_t &Alignment,

                   llvm::DenseMap<const FieldDecl *, uint64_t> &FieldOffsets,

                 llvm::DenseMap<const CXXRecordDecl *, CharUnits> &BaseOffsets,

                 llvm::DenseMap<const CXXRecordDecl *,

                                CharUnits> &VirtualBaseOffsets) override;

  /// Return the amount of memory used by memory buffers, breaking down

  /// by heap-backed versus mmap'ed memory.

  void getMemoryBufferSizes(MemoryBufferSizes &sizes) const override;

  //===--------------------------------------------------------------------===//

  // ExternalSemaSource.

  //===--------------------------------------------------------------------===//

  /// Initialize the semantic source with the Sema instance

  /// being used to perform semantic analysis on the abstract syntax

  /// tree.

  void InitializeSema(Sema &S) override;

  /// Inform the semantic consumer that Sema is no longer available.

  void ForgetSema() override;

  /// Load the contents of the global method pool for a given

  /// selector.

  void ReadMethodPool(Selector Sel) override;

  /// Load the contents of the global method pool for a given

  /// selector if necessary.

  void updateOutOfDateSelector(Selector Sel) override;

  /// Load the set of namespaces that are known to the external source,

  /// which will be used during typo correction.

  void

  ReadKnownNamespaces(SmallVectorImpl<NamespaceDecl*> &Namespaces) override;

  /// Load the set of used but not defined functions or variables with

  /// internal linkage, or used but not defined inline functions.

  void ReadUndefinedButUsed(

      llvm::MapVector<NamedDecl *, SourceLocation> &Undefined) override;

  void ReadMismatchingDeleteExpressions(llvm::MapVector<

      FieldDecl *, llvm::SmallVector<std::pair<SourceLocation, bool>, 4>> &

                                            Exprs) override;

  /// Do last resort, unqualified lookup on a LookupResult that

  /// Sema cannot find.

  ///

  /// \param R a LookupResult that is being recovered.

  ///

  /// \param S the Scope of the identifier occurrence.

  ///

  /// \return true to tell Sema to recover using the LookupResult.

  bool LookupUnqualified(LookupResult &R, Scope *S) override;

  /// Read the set of tentative definitions known to the external Sema

  /// source.

  ///

  /// The external source should append its own tentative definitions to the

  /// given vector of tentative definitions. Note that this routine may be

  /// invoked multiple times; the external source should take care not to

  /// introduce the same declarations repeatedly.

  void ReadTentativeDefinitions(SmallVectorImpl<VarDecl*> &Defs) override;

  /// Read the set of unused file-scope declarations known to the

  /// external Sema source.

  ///

  /// The external source should append its own unused, filed-scope to the

  /// given vector of declarations. Note that this routine may be

  /// invoked multiple times; the external source should take care not to

  /// introduce the same declarations repeatedly.

  void ReadUnusedFileScopedDecls(

                        SmallVectorImpl<const DeclaratorDecl*> &Decls) override;

  /// Read the set of delegating constructors known to the

  /// external Sema source.

  ///

  /// The external source should append its own delegating constructors to the

  /// given vector of declarations. Note that this routine may be

  /// invoked multiple times; the external source should take care not to

  /// introduce the same declarations repeatedly.

  void ReadDelegatingConstructors(

                          SmallVectorImpl<CXXConstructorDecl*> &Decls) override;

  /// Read the set of ext_vector type declarations known to the

  /// external Sema source.

  ///

  /// The external source should append its own ext_vector type declarations to

  /// the given vector of declarations. Note that this routine may be

  /// invoked multiple times; the external source should take care not to

  /// introduce the same declarations repeatedly.

  void ReadExtVectorDecls(SmallVectorImpl<TypedefNameDecl*> &Decls) override;

  /// Read the set of potentially unused typedefs known to the source.

  ///

  /// The external source should append its own potentially unused local

  /// typedefs to the given vector of declarations. Note that this routine may

  /// be invoked multiple times; the external source should take care not to

  /// introduce the same declarations repeatedly.

  void ReadUnusedLocalTypedefNameCandidates(

      llvm::SmallSetVector<const TypedefNameDecl *, 4> &Decls) override;

  /// Read the set of referenced selectors known to the

  /// external Sema source.

  ///

  /// The external source should append its own referenced selectors to the

  /// given vector of selectors. Note that this routine

  /// may be invoked multiple times; the external source should take care not

  /// to introduce the same selectors repeatedly.

  void ReadReferencedSelectors(SmallVectorImpl<std::pair<Selector,

                                              SourceLocation> > &Sels) override;

  /// Read the set of weak, undeclared identifiers known to the

  /// external Sema source.

  ///

  /// The external source should append its own weak, undeclared identifiers to

  /// the given vector. Note that this routine may be invoked multiple times;

  /// the external source should take care not to introduce the same identifiers

  /// repeatedly.

  void ReadWeakUndeclaredIdentifiers(

           SmallVectorImpl<std::pair<IdentifierInfo*, WeakInfo> > &WI) override;

  /// Read the set of used vtables known to the external Sema source.

  ///

  /// The external source should append its own used vtables to the given

  /// vector. Note that this routine may be invoked multiple times; the external

  /// source should take care not to introduce the same vtables repeatedly.

  void ReadUsedVTables(SmallVectorImpl<ExternalVTableUse> &VTables) override;

  /// Read the set of pending instantiations known to the external

  /// Sema source.

  ///

  /// The external source should append its own pending instantiations to the

  /// given vector. Note that this routine may be invoked multiple times; the

  /// external source should take care not to introduce the same instantiations

  /// repeatedly.

  void ReadPendingInstantiations(

     SmallVectorImpl<std::pair<ValueDecl*, SourceLocation> >& Pending) override;

  /// Read the set of late parsed template functions for this source.

  ///

  /// The external source should insert its own late parsed template functions

  /// into the map. Note that this routine may be invoked multiple times; the

  /// external source should take care not to introduce the same map entries

  /// repeatedly.

  void ReadLateParsedTemplates(

      llvm::MapVector<const FunctionDecl *, std::unique_ptr<LateParsedTemplate>>

          &LPTMap) override;

  /// Read the set of decls to be checked for deferred diags.

  ///

  /// The external source should append its own potentially emitted function

  /// and variable decls which may cause deferred diags. Note that this routine

  /// may be invoked multiple times; the external source should take care not to

  /// introduce the same declarations repeatedly.

  void ReadDeclsToCheckForDeferredDiags(

      llvm::SmallSetVector<Decl *, 4> &Decls) override;

  /// \copydoc ExternalSemaSource::CorrectTypo

  /// \note Returns the first nonempty correction.

  TypoCorrection CorrectTypo(const DeclarationNameInfo &Typo,

                             int LookupKind, Scope *S, CXXScopeSpec *SS,

                             CorrectionCandidateCallback &CCC,

                             DeclContext *MemberContext,

                             bool EnteringContext,

                             const ObjCObjectPointerType *OPT) override;

  /// Produces a diagnostic note if one of the attached sources

  /// contains a complete definition for \p T. Queries the sources in list

  /// order until the first one claims that a diagnostic was produced.

  ///

  /// \param Loc the location at which a complete type was required but not

  /// provided

  ///

  /// \param T the \c QualType that should have been complete at \p Loc

  ///

  /// \return true if a diagnostic was produced, false otherwise.

  bool MaybeDiagnoseMissingCompleteType(SourceLocation Loc,

                                        QualType T) override;

  /// LLVM-style RTTI.

  /// \{

  bool isA(const void *ClassID) const override {

    return ClassID == &ID || ExternalSemaSource::isA(ClassID);

  }

  static bool classof(const ExternalASTSource *S) { return S->isA(&ID); }

  /// \}

};

} // end namespace clang

#endif