include/llvm/CodeGen/GCMetadataPrinter.h

   1 //===- llvm/CodeGen/GCMetadataPrinter.h - Prints asm GC tables --*- 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 // The abstract base class GCMetadataPrinter supports writing GC metadata tables
  10 // as assembly code. This is a separate class from GCStrategy in order to allow
  11 // users of the LLVM JIT to avoid linking with the AsmWriter.
  12 //
  13 // Subclasses of GCMetadataPrinter must be registered using the
  14 // GCMetadataPrinterRegistry. This is separate from the GCStrategy itself
  15 // because these subclasses are logically plugins for the AsmWriter.
  16 //
  17 //===----------------------------------------------------------------------===//
  18
  19 #ifndef LLVM_CODEGEN_GCMETADATAPRINTER_H
  20 #define LLVM_CODEGEN_GCMETADATAPRINTER_H
  21
  22 #include "llvm/Support/Registry.h"
  23
  24 namespace llvm {
  25
  26 class AsmPrinter;
  27 class GCMetadataPrinter;
  28 class GCModuleInfo;
  29 class GCStrategy;
  30 class Module;
  31 class StackMaps;
  32
  33 /// GCMetadataPrinterRegistry - The GC assembly printer registry uses all the
  34 /// defaults from Registry.
  35 using GCMetadataPrinterRegistry = Registry<GCMetadataPrinter>;
  36
  37 /// GCMetadataPrinter - Emits GC metadata as assembly code.  Instances are
  38 /// created, managed, and owned by the AsmPrinter.
  39 class GCMetadataPrinter {
  40 private:
  41   friend class AsmPrinter;
  42
  43   GCStrategy *S;
  44
  45 protected:
  46   // May only be subclassed.
  47   GCMetadataPrinter();
  48
  49 public:
  50   GCMetadataPrinter(const GCMetadataPrinter &) = delete;
  51   GCMetadataPrinter &operator=(const GCMetadataPrinter &) = delete;
  52   virtual ~GCMetadataPrinter();
  53
  54   GCStrategy &getStrategy() { return *S; }
  55
  56   /// Called before the assembly for the module is generated by
  57   /// the AsmPrinter (but after target specific hooks.)
  58   virtual void beginAssembly(Module &M, GCModuleInfo &Info, AsmPrinter &AP) {}
  59
  60   /// Called after the assembly for the module is generated by
  61   /// the AsmPrinter (but before target specific hooks)
  62   virtual void finishAssembly(Module &M, GCModuleInfo &Info, AsmPrinter &AP) {}
  63
  64   /// Called when the stack maps are generated. Return true if
  65   /// stack maps with a custom format are generated. Otherwise
  66   /// returns false and the default format will be used.
  67   virtual bool emitStackMaps(StackMaps &SM, AsmPrinter &AP) { return false; }
  68 };
  69
  70 } // end namespace llvm
  71
  72 #endif // LLVM_CODEGEN_GCMETADATAPRINTER_H