llvm/lib/TableGen/TableGenBackendSkeleton.cpp

   1 //===- SkeletonEmitter.cpp - Skeleton TableGen backend          -*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This Tablegen backend emits ...
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "llvm/ADT/StringRef.h"
  14 #include "llvm/TableGen/TableGenBackend.h"
  15
  16 #define DEBUG_TYPE "skeleton-emitter"
  17
  18 namespace llvm {
  19 class RecordKeeper;
  20 class raw_ostream;
  21 } // namespace llvm
  22
  23 using namespace llvm;
  24
  25 namespace {
  26
  27 // Any helper data structures can be defined here. Some backends use
  28 // structs to collect information from the records.
  29
  30 class SkeletonEmitter {
  31 private:
  32   RecordKeeper &Records;
  33
  34 public:
  35   SkeletonEmitter(RecordKeeper &RK) : Records(RK) {}
  36
  37   void run(raw_ostream &OS);
  38 }; // emitter class
  39
  40 } // anonymous namespace
  41
  42 void SkeletonEmitter::run(raw_ostream &OS) {
  43   emitSourceFileHeader("Skeleton data structures", OS);
  44
  45   (void)Records; // To suppress unused variable warning; remove on use.
  46 }
  47
  48 // Choose either option A or B.
  49
  50 //===----------------------------------------------------------------------===//
  51 // Option A: Register the backed as class <SkeletonEmitter>
  52 static TableGen::Emitter::OptClass<SkeletonEmitter>
  53     X("gen-skeleton-class", "Generate example skeleton class");
  54
  55 //===----------------------------------------------------------------------===//
  56 // Option B: Register "EmitSkeleton" directly
  57 // The emitter entry may be private scope.
  58 static void EmitSkeleton(RecordKeeper &RK, raw_ostream &OS) {
  59   // Instantiate the emitter class and invoke run().
  60   SkeletonEmitter(RK).run(OS);
  61 }
  62
  63 static TableGen::Emitter::Opt Y("gen-skeleton-entry", EmitSkeleton,
  64                                 "Generate example skeleton entry");