LLVM  10.0.0svn
TpiHashing.cpp
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1 //===- TpiHashing.cpp -----------------------------------------------------===//
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 
10 
13 #include "llvm/Support/CRC.h"
14 
15 using namespace llvm;
16 using namespace llvm::codeview;
17 using namespace llvm::pdb;
18 
19 // Corresponds to `fUDTAnon`.
20 static bool isAnonymous(StringRef Name) {
21  return Name == "<unnamed-tag>" || Name == "__unnamed" ||
22  Name.endswith("::<unnamed-tag>") || Name.endswith("::__unnamed");
23 }
24 
25 // Computes the hash for a user-defined type record. This could be a struct,
26 // class, union, or enum.
27 static uint32_t getHashForUdt(const TagRecord &Rec,
28  ArrayRef<uint8_t> FullRecord) {
29  ClassOptions Opts = Rec.getOptions();
30  bool ForwardRef = bool(Opts & ClassOptions::ForwardReference);
31  bool Scoped = bool(Opts & ClassOptions::Scoped);
33  bool IsAnon = HasUniqueName && isAnonymous(Rec.getName());
34 
35  if (!ForwardRef && !Scoped && !IsAnon)
36  return hashStringV1(Rec.getName());
37  if (!ForwardRef && HasUniqueName && !IsAnon)
38  return hashStringV1(Rec.getUniqueName());
39  return hashBufferV8(FullRecord);
40 }
41 
42 template <typename T>
44  T Deserialized;
45  if (auto E = TypeDeserializer::deserializeAs(const_cast<CVType &>(Rec),
46  Deserialized))
47  return std::move(E);
48  return getHashForUdt(Deserialized, Rec.data());
49 }
50 
51 template <typename T>
53  T Deserialized;
54  if (auto E = TypeDeserializer::deserializeAs(const_cast<CVType &>(Rec),
55  Deserialized))
56  return std::move(E);
57 
58  ClassOptions Opts = Deserialized.getOptions();
59 
60  bool ForwardRef = bool(Opts & ClassOptions::ForwardReference);
61 
62  uint32_t ThisRecordHash = getHashForUdt(Deserialized, Rec.data());
63 
64  // If we don't have a forward ref we can't compute the hash of it from the
65  // full record because it requires hashing the entire buffer.
66  if (!ForwardRef)
67  return TagRecordHash{std::move(Deserialized), ThisRecordHash, 0};
68 
69  bool Scoped = bool(Opts & ClassOptions::Scoped);
70 
71  StringRef NameToHash =
72  Scoped ? Deserialized.getUniqueName() : Deserialized.getName();
73  uint32_t FullHash = hashStringV1(NameToHash);
74  return TagRecordHash{std::move(Deserialized), FullHash, ThisRecordHash};
75 }
76 
77 template <typename T>
79  T Deserialized;
80  if (auto E = TypeDeserializer::deserializeAs(const_cast<CVType &>(Rec),
81  Deserialized))
82  return std::move(E);
83  char Buf[4];
84  support::endian::write32le(Buf, Deserialized.getUDT().getIndex());
85  return hashStringV1(StringRef(Buf, 4));
86 }
87 
89  switch (Type.kind()) {
90  case LF_CLASS:
91  case LF_STRUCTURE:
92  case LF_INTERFACE:
93  return getTagRecordHashForUdt<ClassRecord>(Type);
94  case LF_UNION:
95  return getTagRecordHashForUdt<UnionRecord>(Type);
96  case LF_ENUM:
97  return getTagRecordHashForUdt<EnumRecord>(Type);
98  default:
99  assert(false && "Type is not a tag record!");
100  }
101  return make_error<StringError>("Invalid record type",
103 }
104 
106  switch (Rec.kind()) {
107  case LF_CLASS:
108  case LF_STRUCTURE:
109  case LF_INTERFACE:
110  return getHashForUdt<ClassRecord>(Rec);
111  case LF_UNION:
112  return getHashForUdt<UnionRecord>(Rec);
113  case LF_ENUM:
114  return getHashForUdt<EnumRecord>(Rec);
115 
116  case LF_UDT_SRC_LINE:
117  return getSourceLineHash<UdtSourceLineRecord>(Rec);
118  case LF_UDT_MOD_SRC_LINE:
119  return getSourceLineHash<UdtModSourceLineRecord>(Rec);
120 
121  default:
122  break;
123  }
124 
125  // Run CRC32 over the bytes. This corresponds to `hashBufv8`.
126  JamCRC JC(/*Init=*/0U);
127  JC.update(Rec.data());
128  return JC.getCRC();
129 }
uint32_t getCRC() const
Definition: CRC.h:52
uint32_t hashBufferV8(ArrayRef< uint8_t > Data)
Definition: Hash.cpp:80
Kind kind() const
Definition: CVRecord.h:43
LLVM_NODISCARD bool endswith(StringRef Suffix) const
Check if this string ends with the given Suffix.
Definition: StringRef.h:281
This class represents lattice values for constants.
Definition: AllocatorList.h:23
amdgpu Simplify well known AMD library false FunctionCallee Value const Twine & Name
void write32le(void *P, uint32_t V)
Definition: Endian.h:418
static bool isAnonymous(StringRef Name)
Definition: TpiHashing.cpp:20
StringRef getName() const
Definition: TypeRecord.h:459
static Expected< uint32_t > getSourceLineHash(const CVType &Rec)
Definition: TpiHashing.cpp:78
Tagged union holding either a T or a Error.
Definition: yaml2obj.h:21
Expected< TagRecordHash > hashTagRecord(const codeview::CVType &Type)
Given a CVType referring to a class, structure, union, or enum, compute the hash of its forward decl ...
Definition: TpiHashing.cpp:88
ClassOptions getOptions() const
Definition: TypeRecord.h:457
ArrayRef< uint8_t > data() const
Definition: CVRecord.h:50
Expected< uint32_t > hashTypeRecord(const llvm::codeview::CVType &Type)
Definition: TpiHashing.cpp:105
uint32_t hashStringV1(StringRef Str)
Definition: Hash.cpp:20
The instances of the Type class are immutable: once they are created, they are never changed...
Definition: Type.h:46
static GCRegistry::Add< CoreCLRGC > E("coreclr", "CoreCLR-compatible GC")
StringRef getUniqueName() const
Definition: TypeRecord.h:460
static Error deserializeAs(CVType &CVT, T &Record)
static Expected< TagRecordHash > getTagRecordHashForUdt(const CVType &Rec)
Definition: TpiHashing.cpp:52
static uint32_t getHashForUdt(const TagRecord &Rec, ArrayRef< uint8_t > FullRecord)
Definition: TpiHashing.cpp:27
void update(ArrayRef< uint8_t > Data)
Definition: CRC.cpp:95
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:48
std::error_code inconvertibleErrorCode()
The value returned by this function can be returned from convertToErrorCode for Error values where no...
Definition: Error.cpp:77