text: //===--- IncrementalParser.h - Incremental Compilation ----------*- 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 implements the class which performs incremental code compilation.
  //
  //===----------------------------------------------------------------------===//
  
  #ifndef LLVM_CLANG_LIB_INTERPRETER_INCREMENTALPARSER_H
  #define LLVM_CLANG_LIB_INTERPRETER_INCREMENTALPARSER_H
  
  #include "clang/Interpreter/PartialTranslationUnit.h"
  
  #include "clang/AST/GlobalDecl.h"
  
  #include "llvm/ADT/ArrayRef.h"
  #include "llvm/ADT/StringRef.h"
  #include "llvm/Support/Error.h"
  
  #include <list>
  #include <memory>
  namespace llvm {
  class LLVMContext;
  }
  
  namespace clang {
  class ASTConsumer;
  class CompilerInstance;
  class IncrementalAction;
  class Parser;
  
  /// Provides support for incremental compilation. Keeps track of the state
  /// changes between the subsequent incremental input.
  ///
  class IncrementalParser {
    /// Long-lived, incremental parsing action.
    std::unique_ptr<IncrementalAction> Act;
  
    /// Compiler instance performing the incremental compilation.
    std::unique_ptr<CompilerInstance> CI;
  
    /// Parser.
    std::unique_ptr<Parser> P;
  
    /// Consumer to process the produced top level decls. Owned by Act.
    ASTConsumer *Consumer = nullptr;
  
    /// Counts the number of direct user input lines that have been parsed.
    unsigned InputCount = 0;
  
    /// List containing every information about every incrementally parsed piece
    /// of code.
    std::list<PartialTranslationUnit> PTUs;
  
  public:
    IncrementalParser(std::unique_ptr<CompilerInstance> Instance,
                      llvm::LLVMContext &LLVMCtx, llvm::Error &Err);
    ~IncrementalParser();
  
    const CompilerInstance *getCI() const { return CI.get(); }
  
    /// Parses incremental input by creating an in-memory file.
    ///\returns a \c PartialTranslationUnit which holds information about the
    /// \c TranslationUnitDecl and \c llvm::Module corresponding to the input.
    llvm::Expected<PartialTranslationUnit &> Parse(llvm::StringRef Input);
  
    /// Uses the CodeGenModule mangled name cache and avoids recomputing.
    ///\returns the mangled name of a \c GD.
    llvm::StringRef GetMangledName(GlobalDecl GD) const;
  
  private:
    llvm::Expected<PartialTranslationUnit &> ParseOrWrapTopLevelDecl();
  };
  } // end namespace clang
  
  #endif // LLVM_CLANG_LIB_INTERPRETER_INCREMENTALPARSER_H
  