text: //===- TableGenBackends.h - Declarations for LLVM TableGen Backends -------===//
  //
  //                     The LLVM Compiler Infrastructure
  //
  // This file is distributed under the University of Illinois Open Source
  // License. See LICENSE.TXT for details.
  //
  //===----------------------------------------------------------------------===//
  //
  // This file contains the declarations for all of the LLVM TableGen
  // backends. A "TableGen backend" is just a function. See below for a
  // precise description.
  //
  //===----------------------------------------------------------------------===//
  
  #ifndef LLVM_UTILS_TABLEGEN_TABLEGENBACKENDS_H
  #define LLVM_UTILS_TABLEGEN_TABLEGENBACKENDS_H
  
  // A TableGen backend is a function that looks like
  //
  //    EmitFoo(RecordKeeper &RK, raw_ostream &OS /*, anything else you need */ )
  //
  // What you do inside of that function is up to you, but it will usually
  // involve generating C++ code to the provided raw_ostream.
  //
  // The RecordKeeper is just a top-level container for an in-memory
  // representation of the data encoded in the TableGen file. What a TableGen
  // backend does is walk around that in-memory representation and generate
  // stuff based on the information it contains.
  //
  // The in-memory representation is a node-graph (think of it like JSON but
  // with a richer ontology of types), where the nodes are subclasses of
  // Record. The methods `getClass`, `getDef` are the basic interface to
  // access the node-graph.  RecordKeeper also provides a handy method
  // `getAllDerivedDefinitions`. Consult "include/llvm/TableGen/Record.h" for
  // the exact interfaces provided by Record's and RecordKeeper.
  //
  // A common pattern for TableGen backends is for the EmitFoo function to
  // instantiate a class which holds some context for the generation process,
  // and then have most of the work happen in that class's methods. This
  // pattern partly has historical roots in the previous TableGen backend API
  // that involved a class and an invocation like `FooEmitter(RK).run(OS)`.
  //
  // Remember to wrap private things in an anonymous namespace. For most
  // backends, this means that the EmitFoo function is the only thing not in
  // the anonymous namespace.
  
  
  // FIXME: Reorganize TableGen so that build dependencies can be more
  // accurately expressed. Currently, touching any of the emitters (or
  // anything that they transitively depend on) causes everything dependent
  // on TableGen to be rebuilt (this includes all the targets!). Perhaps have
  // a standalone TableGen binary and have the backends be loadable modules
  // of some sort; then the dependency could be expressed as being on the
  // module, and all the modules would have a common dependency on the
  // TableGen binary with as few dependencies as possible on the rest of
  // LLVM.
  
  
  namespace llvm {
  
  class raw_ostream;
  class RecordKeeper;
  
  void EmitIntrinsics(RecordKeeper &RK, raw_ostream &OS, bool TargetOnly = false);
  void EmitAsmMatcher(RecordKeeper &RK, raw_ostream &OS);
  void EmitAsmWriter(RecordKeeper &RK, raw_ostream &OS);
  void EmitCallingConv(RecordKeeper &RK, raw_ostream &OS);
  void EmitCodeEmitter(RecordKeeper &RK, raw_ostream &OS);
  void EmitDAGISel(RecordKeeper &RK, raw_ostream &OS);
  void EmitDFAPacketizer(RecordKeeper &RK, raw_ostream &OS);
  void EmitDisassembler(RecordKeeper &RK, raw_ostream &OS);
  void EmitFastISel(RecordKeeper &RK, raw_ostream &OS);
  void EmitInstrInfo(RecordKeeper &RK, raw_ostream &OS);
  void EmitPseudoLowering(RecordKeeper &RK, raw_ostream &OS);
  void EmitRegisterInfo(RecordKeeper &RK, raw_ostream &OS);
  void EmitSubtarget(RecordKeeper &RK, raw_ostream &OS);
  void EmitMapTable(RecordKeeper &RK, raw_ostream &OS);
  void EmitOptParser(RecordKeeper &RK, raw_ostream &OS);
  void EmitCTags(RecordKeeper &RK, raw_ostream &OS);
  void EmitAttributes(RecordKeeper &RK, raw_ostream &OS);
  void EmitSearchableTables(RecordKeeper &RK, raw_ostream &OS);
  void EmitGlobalISel(RecordKeeper &RK, raw_ostream &OS);
  void EmitX86EVEX2VEXTables(RecordKeeper &RK, raw_ostream &OS);
  void EmitRegisterBank(RecordKeeper &RK, raw_ostream &OS);
  
  } // End llvm namespace
  
  #endif
  