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