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