1 //===- TpiHashing.cpp -----------------------------------------------------===//
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 #include "llvm/DebugInfo/PDB/Native/TpiHashing.h"
11 
12 #include "llvm/DebugInfo/CodeView/TypeDeserializer.h"
13 #include "llvm/DebugInfo/PDB/Native/Hash.h"
14 #include "llvm/DebugInfo/PDB/Native/RawError.h"
15 
16 using namespace llvm;
17 using namespace llvm::codeview;
18 using namespace llvm::pdb;
19 
20 // Corresponds to `fUDTAnon`.
21 template <typename T> static bool isAnonymous(T &Rec) {
22   StringRef Name = Rec.getName();
23   return Name == "<unnamed-tag>" || Name == "__unnamed" ||
24          Name.endswith("::<unnamed-tag>") || Name.endswith("::__unnamed");
25 }
26 
27 // Computes a hash for a given TPI record.
28 template <typename T>
29 static uint32_t getTpiHash(T &Rec, ArrayRef<uint8_t> FullRecord) {
30   auto Opts = static_cast<uint16_t>(Rec.getOptions());
31 
32   bool ForwardRef =
33       Opts & static_cast<uint16_t>(ClassOptions::ForwardReference);
34   bool Scoped = Opts & static_cast<uint16_t>(ClassOptions::Scoped);
35   bool UniqueName = Opts & static_cast<uint16_t>(ClassOptions::HasUniqueName);
36   bool IsAnon = UniqueName && isAnonymous(Rec);
37 
38   if (!ForwardRef && !Scoped && !IsAnon)
39     return hashStringV1(Rec.getName());
40   if (!ForwardRef && UniqueName && !IsAnon)
41     return hashStringV1(Rec.getUniqueName());
42   return hashBufferV8(FullRecord);
43 }
44 
45 template <typename T> static uint32_t getSourceLineHash(T &Rec) {
46   char Buf[4];
47   support::endian::write32le(Buf, Rec.getUDT().getIndex());
48   return hashStringV1(StringRef(Buf, 4));
49 }
50 
51 void TpiHashUpdater::visitKnownRecordImpl(CVType &CVR,
52                                           UdtSourceLineRecord &Rec) {
53   CVR.Hash = getSourceLineHash(Rec);
54 }
55 
56 void TpiHashUpdater::visitKnownRecordImpl(CVType &CVR,
57                                           UdtModSourceLineRecord &Rec) {
58   CVR.Hash = getSourceLineHash(Rec);
59 }
60 
61 void TpiHashUpdater::visitKnownRecordImpl(CVType &CVR, ClassRecord &Rec) {
62   CVR.Hash = getTpiHash(Rec, CVR.data());
63 }
64 
65 void TpiHashUpdater::visitKnownRecordImpl(CVType &CVR, EnumRecord &Rec) {
66   CVR.Hash = getTpiHash(Rec, CVR.data());
67 }
68 
69 void TpiHashUpdater::visitKnownRecordImpl(CVType &CVR, UnionRecord &Rec) {
70   CVR.Hash = getTpiHash(Rec, CVR.data());
71 }
72 
73 Error TpiHashVerifier::visitKnownRecord(CVType &CVR, UdtSourceLineRecord &Rec) {
74   return verifySourceLine(Rec.getUDT());
75 }
76 
77 Error TpiHashVerifier::visitKnownRecord(CVType &CVR,
78                                         UdtModSourceLineRecord &Rec) {
79   return verifySourceLine(Rec.getUDT());
80 }
81 
82 Error TpiHashVerifier::visitKnownRecord(CVType &CVR, ClassRecord &Rec) {
83   if (getTpiHash(Rec, CVR.data()) % NumHashBuckets != HashValues[Index])
84     return errorInvalidHash();
85   return Error::success();
86 }
87 Error TpiHashVerifier::visitKnownRecord(CVType &CVR, EnumRecord &Rec) {
88   if (getTpiHash(Rec, CVR.data()) % NumHashBuckets != HashValues[Index])
89     return errorInvalidHash();
90   return Error::success();
91 }
92 Error TpiHashVerifier::visitKnownRecord(CVType &CVR, UnionRecord &Rec) {
93   if (getTpiHash(Rec, CVR.data()) % NumHashBuckets != HashValues[Index])
94     return errorInvalidHash();
95   return Error::success();
96 }
97 
98 Error TpiHashVerifier::verifySourceLine(codeview::TypeIndex TI) {
99   char Buf[4];
100   support::endian::write32le(Buf, TI.getIndex());
101   uint32_t Hash = hashStringV1(StringRef(Buf, 4));
102   if (Hash % NumHashBuckets != HashValues[Index])
103     return errorInvalidHash();
104   return Error::success();
105 }
106 
107 Error TpiHashVerifier::visitTypeBegin(CVType &Rec) {
108   ++Index;
109   RawRecord = Rec;
110   return Error::success();
111 }
112