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