1 //===- TpiHashing.h ---------------------------------------------*- 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 #ifndef LLVM_DEBUGINFO_PDB_NATIVE_TPIHASHING_H
10 #define LLVM_DEBUGINFO_PDB_NATIVE_TPIHASHING_H
11 
12 #include "llvm/DebugInfo/CodeView/TypeRecord.h"
13 #include "llvm/Support/Error.h"
14 
15 namespace llvm {
16 namespace pdb {
17 
18 Expected<uint32_t> hashTypeRecord(const llvm::codeview::CVType &Type);
19 
20 struct TagRecordHash {
21   explicit TagRecordHash(codeview::ClassRecord CR, uint32_t Full,
22                          uint32_t Forward)
23       : FullRecordHash(Full), ForwardDeclHash(Forward), Class(std::move(CR)) {
24     State = 0;
25   }
26 
27   explicit TagRecordHash(codeview::EnumRecord ER, uint32_t Full,
28                          uint32_t Forward)
29       : FullRecordHash(Full), ForwardDeclHash(Forward), Enum(std::move(ER)) {
30     State = 1;
31   }
32 
33   explicit TagRecordHash(codeview::UnionRecord UR, uint32_t Full,
34                          uint32_t Forward)
35       : FullRecordHash(Full), ForwardDeclHash(Forward), Union(std::move(UR)) {
36     State = 2;
37   }
38 
39   uint32_t FullRecordHash;
40   uint32_t ForwardDeclHash;
41 
42   codeview::TagRecord &getRecord() {
43     switch (State) {
44     case 0:
45       return Class;
46     case 1:
47       return Enum;
48     case 2:
49       return Union;
50     }
51     llvm_unreachable("unreachable!");
52   }
53 
54 private:
55   union {
56     codeview::ClassRecord Class;
57     codeview::EnumRecord Enum;
58     codeview::UnionRecord Union;
59   };
60 
61   uint8_t State = 0;
62 };
63 
64 /// Given a CVType referring to a class, structure, union, or enum, compute
65 /// the hash of its forward decl and full decl.
66 Expected<TagRecordHash> hashTagRecord(const codeview::CVType &Type);
67 
68 } // end namespace pdb
69 } // end namespace llvm
70 
71 #endif // LLVM_DEBUGINFO_PDB_NATIVE_TPIHASHING_H
72