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