1 //===- TpiHashing.cpp -----------------------------------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 #include "llvm/DebugInfo/PDB/Native/TpiHashing.h"
12 #include "llvm/DebugInfo/CodeView/TypeDeserializer.h"
13 #include "llvm/DebugInfo/PDB/Native/Hash.h"
14 #include "llvm/Support/JamCRC.h"
17 using namespace llvm::codeview;
18 using namespace llvm::pdb;
20 // Corresponds to `fUDTAnon`.
21 static bool isAnonymous(StringRef Name) {
22 return Name == "<unnamed-tag>" || Name == "__unnamed" ||
23 Name.endswith("::<unnamed-tag>") || Name.endswith("::__unnamed");
26 // Computes the hash for a user-defined type record. This could be a struct,
27 // class, union, or enum.
28 static uint32_t getHashForUdt(const TagRecord &Rec,
29 ArrayRef<uint8_t> FullRecord) {
30 ClassOptions Opts = Rec.getOptions();
31 bool ForwardRef = bool(Opts & ClassOptions::ForwardReference);
32 bool Scoped = bool(Opts & ClassOptions::Scoped);
33 bool HasUniqueName = bool(Opts & ClassOptions::HasUniqueName);
34 bool IsAnon = HasUniqueName && isAnonymous(Rec.getName());
36 if (!ForwardRef && !Scoped && !IsAnon)
37 return hashStringV1(Rec.getName());
38 if (!ForwardRef && HasUniqueName && !IsAnon)
39 return hashStringV1(Rec.getUniqueName());
40 return hashBufferV8(FullRecord);
44 static Expected<uint32_t> getHashForUdt(const CVType &Rec) {
46 if (auto E = TypeDeserializer::deserializeAs(const_cast<CVType &>(Rec),
49 return getHashForUdt(Deserialized, Rec.data());
53 static Expected<TagRecordHash> getTagRecordHashForUdt(const CVType &Rec) {
55 if (auto E = TypeDeserializer::deserializeAs(const_cast<CVType &>(Rec),
59 ClassOptions Opts = Deserialized.getOptions();
61 bool ForwardRef = bool(Opts & ClassOptions::ForwardReference);
63 uint32_t ThisRecordHash = getHashForUdt(Deserialized, Rec.data());
65 // If we don't have a forward ref we can't compute the hash of it from the
66 // full record because it requires hashing the entire buffer.
68 return TagRecordHash{std::move(Deserialized), ThisRecordHash, 0};
70 bool Scoped = bool(Opts & ClassOptions::Scoped);
72 StringRef NameToHash =
73 Scoped ? Deserialized.getUniqueName() : Deserialized.getName();
74 uint32_t FullHash = hashStringV1(NameToHash);
75 return TagRecordHash{std::move(Deserialized), FullHash, ThisRecordHash};
79 static Expected<uint32_t> getSourceLineHash(const CVType &Rec) {
81 if (auto E = TypeDeserializer::deserializeAs(const_cast<CVType &>(Rec),
85 support::endian::write32le(Buf, Deserialized.getUDT().getIndex());
86 return hashStringV1(StringRef(Buf, 4));
89 Expected<TagRecordHash> llvm::pdb::hashTagRecord(const codeview::CVType &Type) {
90 switch (Type.kind()) {
94 return getTagRecordHashForUdt<ClassRecord>(Type);
96 return getTagRecordHashForUdt<UnionRecord>(Type);
98 return getTagRecordHashForUdt<EnumRecord>(Type);
100 assert(false && "Type is not a tag record!");
102 return make_error<StringError>("Invalid record type",
103 inconvertibleErrorCode());
106 Expected<uint32_t> llvm::pdb::hashTypeRecord(const CVType &Rec) {
107 switch (Rec.kind()) {
111 return getHashForUdt<ClassRecord>(Rec);
113 return getHashForUdt<UnionRecord>(Rec);
115 return getHashForUdt<EnumRecord>(Rec);
117 case LF_UDT_SRC_LINE:
118 return getSourceLineHash<UdtSourceLineRecord>(Rec);
119 case LF_UDT_MOD_SRC_LINE:
120 return getSourceLineHash<UdtModSourceLineRecord>(Rec);
126 // Run CRC32 over the bytes. This corresponds to `hashBufv8`.
127 JamCRC JC(/*Init=*/0U);
128 ArrayRef<char> Bytes(reinterpret_cast<const char *>(Rec.data().data()),