llvm/lib/Bitcode/Reader/MetadataLoader.h

   1 //===-- Bitcode/Reader/MetadataLoader.h - Load Metadatas -------*- 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 class handles loading Metadatas.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #ifndef LLVM_LIB_BITCODE_READER_METADATALOADER_H
  14 #define LLVM_LIB_BITCODE_READER_METADATALOADER_H
  15
  16 #include "llvm/Support/Error.h"
  17
  18 #include <functional>
  19 #include <memory>
  20
  21 namespace llvm {
  22 class BitcodeReaderValueList;
  23 class BitstreamCursor;
  24 class DISubprogram;
  25 class Function;
  26 class Instruction;
  27 class Metadata;
  28 class Module;
  29 class Type;
  30 template <typename T> class ArrayRef;
  31
  32 typedef std::function<Type *(unsigned)> GetTypeByIDTy;
  33
  34 typedef std::function<unsigned(unsigned, unsigned)> GetContainedTypeIDTy;
  35
  36 typedef std::function<void(Metadata **, unsigned, GetTypeByIDTy,
  37                            GetContainedTypeIDTy)>
  38     MDTypeCallbackTy;
  39
  40 struct MetadataLoaderCallbacks {
  41   GetTypeByIDTy GetTypeByID;
  42   GetContainedTypeIDTy GetContainedTypeID;
  43   std::optional<MDTypeCallbackTy> MDType;
  44 };
  45
  46 /// Helper class that handles loading Metadatas and keeping them available.
  47 class MetadataLoader {
  48   class MetadataLoaderImpl;
  49   std::unique_ptr<MetadataLoaderImpl> Pimpl;
  50   Error parseMetadata(bool ModuleLevel);
  51
  52 public:
  53   ~MetadataLoader();
  54   MetadataLoader(BitstreamCursor &Stream, Module &TheModule,
  55                  BitcodeReaderValueList &ValueList, bool IsImporting,
  56                  MetadataLoaderCallbacks Callbacks);
  57   MetadataLoader &operator=(MetadataLoader &&);
  58   MetadataLoader(MetadataLoader &&);
  59
  60   // Parse a module metadata block
  61   Error parseModuleMetadata() { return parseMetadata(true); }
  62
  63   // Parse a function metadata block
  64   Error parseFunctionMetadata() { return parseMetadata(false); }
  65
  66   /// Set the mode to strip TBAA metadata on load.
  67   void setStripTBAA(bool StripTBAA = true);
  68
  69   /// Return true if the Loader is stripping TBAA metadata.
  70   bool isStrippingTBAA();
  71
  72   // Return true there are remaining unresolved forward references.
  73   bool hasFwdRefs() const;
  74
  75   /// Return the given metadata, creating a replaceable forward reference if
  76   /// necessary.
  77   Metadata *getMetadataFwdRefOrLoad(unsigned Idx);
  78
  79   /// Return the DISubprogram metadata for a Function if any, null otherwise.
  80   DISubprogram *lookupSubprogramForFunction(Function *F);
  81
  82   /// Parse a `METADATA_ATTACHMENT` block for a function.
  83   Error parseMetadataAttachment(Function &F,
  84                                 ArrayRef<Instruction *> InstructionList);
  85
  86   /// Parse a `METADATA_KIND` block for the current module.
  87   Error parseMetadataKinds();
  88
  89   unsigned size() const;
  90   void shrinkTo(unsigned N);
  91
  92   /// Perform bitcode upgrades on llvm.dbg.* calls.
  93   void upgradeDebugIntrinsics(Function &F);
  94 };
  95 }
  96
  97 #endif // LLVM_LIB_BITCODE_READER_METADATALOADER_H