1 //===-- Bitcode/Reader/MetadataLoader.h - Load Metadatas -------*- C++ -*-====//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This class handles loading Metadatas.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_LIB_BITCODE_READER_METADATALOADER_H
15 #define LLVM_LIB_BITCODE_READER_METADATALOADER_H
16 
17 #include "llvm/ADT/SmallVector.h"
18 #include "llvm/Support/Error.h"
19 
20 #include <functional>
21 #include <memory>
22 
23 namespace llvm {
24 class BitcodeReaderValueList;
25 class BitstreamCursor;
26 class DISubprogram;
27 class Error;
28 class Function;
29 class Instruction;
30 class Metadata;
31 class MDNode;
32 class Module;
33 class Type;
34 
35 /// Helper class that handles loading Metadatas and keeping them available.
36 class MetadataLoader {
37   class MetadataLoaderImpl;
38   std::unique_ptr<MetadataLoaderImpl> Pimpl;
39   Error parseMetadata(bool ModuleLevel);
40 
41 public:
42   ~MetadataLoader();
43   MetadataLoader(BitstreamCursor &Stream, Module &TheModule,
44                  BitcodeReaderValueList &ValueList,
45                  std::function<Type *(unsigned)> getTypeByID);
46   MetadataLoader &operator=(MetadataLoader &&);
47   MetadataLoader(MetadataLoader &&);
48 
49   // Parse a module metadata block
50   Error parseModuleMetadata() { return parseMetadata(true); }
51 
52   // Parse a function metadata block
53   Error parseFunctionMetadata() { return parseMetadata(false); }
54 
55   // Return true there are remaining unresolved forward references.
56   bool hasFwdRefs() const;
57 
58   /// Return the given metadata, creating a replaceable forward reference if
59   /// necessary.
60   Metadata *getMetadataFwdRef(unsigned Idx);
61 
62   MDNode *getMDNodeFwdRefOrNull(unsigned Idx);
63 
64   /// Return the DISubprogra metadata for a Function if any, null otherwise.
65   DISubprogram *lookupSubprogramForFunction(Function *F);
66 
67   /// Parse a `METADATA_ATTACHMENT` block for a function.
68   Error parseMetadataAttachment(
69       Function &F, const SmallVectorImpl<Instruction *> &InstructionList);
70 
71   /// Parse a `METADATA_KIND` block for the current module.
72   Error parseMetadataKinds();
73 
74   unsigned size() const;
75   void shrinkTo(unsigned N);
76 };
77 }
78 
79 #endif // LLVM_LIB_BITCODE_READER_METADATALOADER_H
80