1 //===- CoverageMappingReader.h - Code coverage mapping reader ---*- 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 // This file contains support for reading coverage mapping data for
10 // instrumentation based coverage.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_PROFILEDATA_COVERAGE_COVERAGEMAPPINGREADER_H
15 #define LLVM_PROFILEDATA_COVERAGE_COVERAGEMAPPINGREADER_H
16 
17 #include "llvm/ADT/ArrayRef.h"
18 #include "llvm/ADT/StringRef.h"
19 #include "llvm/ProfileData/Coverage/CoverageMapping.h"
20 #include "llvm/ProfileData/InstrProf.h"
21 #include "llvm/Support/Error.h"
22 #include "llvm/Support/MemoryBuffer.h"
23 #include <cstddef>
24 #include <cstdint>
25 #include <iterator>
26 #include <memory>
27 #include <vector>
28 
29 namespace llvm {
30 namespace coverage {
31 
32 class CoverageMappingReader;
33 
34 /// Coverage mapping information for a single function.
35 struct CoverageMappingRecord {
36   StringRef FunctionName;
37   uint64_t FunctionHash;
38   ArrayRef<StringRef> Filenames;
39   ArrayRef<CounterExpression> Expressions;
40   ArrayRef<CounterMappingRegion> MappingRegions;
41 };
42 
43 /// A file format agnostic iterator over coverage mapping data.
44 class CoverageMappingIterator
45     : public std::iterator<std::input_iterator_tag, CoverageMappingRecord> {
46   CoverageMappingReader *Reader;
47   CoverageMappingRecord Record;
48   coveragemap_error ReadErr;
49 
50   void increment();
51 
52 public:
53   CoverageMappingIterator()
54       : Reader(nullptr), Record(), ReadErr(coveragemap_error::success) {}
55 
56   CoverageMappingIterator(CoverageMappingReader *Reader)
57       : Reader(Reader), Record(), ReadErr(coveragemap_error::success) {
58     increment();
59   }
60 
61   ~CoverageMappingIterator() {
62     if (ReadErr != coveragemap_error::success)
63       llvm_unreachable("Unexpected error in coverage mapping iterator");
64   }
65 
66   CoverageMappingIterator &operator++() {
67     increment();
68     return *this;
69   }
70   bool operator==(const CoverageMappingIterator &RHS) {
71     return Reader == RHS.Reader;
72   }
73   bool operator!=(const CoverageMappingIterator &RHS) {
74     return Reader != RHS.Reader;
75   }
76   Expected<CoverageMappingRecord &> operator*() {
77     if (ReadErr != coveragemap_error::success) {
78       auto E = make_error<CoverageMapError>(ReadErr);
79       ReadErr = coveragemap_error::success;
80       return std::move(E);
81     }
82     return Record;
83   }
84   Expected<CoverageMappingRecord *> operator->() {
85     if (ReadErr != coveragemap_error::success) {
86       auto E = make_error<CoverageMapError>(ReadErr);
87       ReadErr = coveragemap_error::success;
88       return std::move(E);
89     }
90     return &Record;
91   }
92 };
93 
94 class CoverageMappingReader {
95 public:
96   virtual ~CoverageMappingReader() = default;
97 
98   virtual Error readNextRecord(CoverageMappingRecord &Record) = 0;
99   CoverageMappingIterator begin() { return CoverageMappingIterator(this); }
100   CoverageMappingIterator end() { return CoverageMappingIterator(); }
101 };
102 
103 /// Base class for the raw coverage mapping and filenames data readers.
104 class RawCoverageReader {
105 protected:
106   StringRef Data;
107 
108   RawCoverageReader(StringRef Data) : Data(Data) {}
109 
110   Error readULEB128(uint64_t &Result);
111   Error readIntMax(uint64_t &Result, uint64_t MaxPlus1);
112   Error readSize(uint64_t &Result);
113   Error readString(StringRef &Result);
114 };
115 
116 /// Reader for the raw coverage filenames.
117 class RawCoverageFilenamesReader : public RawCoverageReader {
118   std::vector<StringRef> &Filenames;
119 
120 public:
121   RawCoverageFilenamesReader(StringRef Data, std::vector<StringRef> &Filenames)
122       : RawCoverageReader(Data), Filenames(Filenames) {}
123   RawCoverageFilenamesReader(const RawCoverageFilenamesReader &) = delete;
124   RawCoverageFilenamesReader &
125   operator=(const RawCoverageFilenamesReader &) = delete;
126 
127   Error read();
128 };
129 
130 /// Checks if the given coverage mapping data is exported for
131 /// an unused function.
132 class RawCoverageMappingDummyChecker : public RawCoverageReader {
133 public:
134   RawCoverageMappingDummyChecker(StringRef MappingData)
135       : RawCoverageReader(MappingData) {}
136 
137   Expected<bool> isDummy();
138 };
139 
140 /// Reader for the raw coverage mapping data.
141 class RawCoverageMappingReader : public RawCoverageReader {
142   ArrayRef<StringRef> TranslationUnitFilenames;
143   std::vector<StringRef> &Filenames;
144   std::vector<CounterExpression> &Expressions;
145   std::vector<CounterMappingRegion> &MappingRegions;
146 
147 public:
148   RawCoverageMappingReader(StringRef MappingData,
149                            ArrayRef<StringRef> TranslationUnitFilenames,
150                            std::vector<StringRef> &Filenames,
151                            std::vector<CounterExpression> &Expressions,
152                            std::vector<CounterMappingRegion> &MappingRegions)
153       : RawCoverageReader(MappingData),
154         TranslationUnitFilenames(TranslationUnitFilenames),
155         Filenames(Filenames), Expressions(Expressions),
156         MappingRegions(MappingRegions) {}
157   RawCoverageMappingReader(const RawCoverageMappingReader &) = delete;
158   RawCoverageMappingReader &
159   operator=(const RawCoverageMappingReader &) = delete;
160 
161   Error read();
162 
163 private:
164   Error decodeCounter(unsigned Value, Counter &C);
165   Error readCounter(Counter &C);
166   Error
167   readMappingRegionsSubArray(std::vector<CounterMappingRegion> &MappingRegions,
168                              unsigned InferredFileID, size_t NumFileIDs);
169 };
170 
171 /// Reader for the coverage mapping data that is emitted by the
172 /// frontend and stored in an object file.
173 class BinaryCoverageReader : public CoverageMappingReader {
174 public:
175   struct ProfileMappingRecord {
176     CovMapVersion Version;
177     StringRef FunctionName;
178     uint64_t FunctionHash;
179     StringRef CoverageMapping;
180     size_t FilenamesBegin;
181     size_t FilenamesSize;
182 
183     ProfileMappingRecord(CovMapVersion Version, StringRef FunctionName,
184                          uint64_t FunctionHash, StringRef CoverageMapping,
185                          size_t FilenamesBegin, size_t FilenamesSize)
186         : Version(Version), FunctionName(FunctionName),
187           FunctionHash(FunctionHash), CoverageMapping(CoverageMapping),
188           FilenamesBegin(FilenamesBegin), FilenamesSize(FilenamesSize) {}
189   };
190 
191 private:
192   std::vector<StringRef> Filenames;
193   std::vector<ProfileMappingRecord> MappingRecords;
194   InstrProfSymtab ProfileNames;
195   size_t CurrentRecord = 0;
196   std::vector<StringRef> FunctionsFilenames;
197   std::vector<CounterExpression> Expressions;
198   std::vector<CounterMappingRegion> MappingRegions;
199 
200   BinaryCoverageReader() = default;
201 
202 public:
203   BinaryCoverageReader(const BinaryCoverageReader &) = delete;
204   BinaryCoverageReader &operator=(const BinaryCoverageReader &) = delete;
205 
206   static Expected<std::vector<std::unique_ptr<BinaryCoverageReader>>>
207   create(MemoryBufferRef ObjectBuffer, StringRef Arch,
208          SmallVectorImpl<std::unique_ptr<MemoryBuffer>> &ObjectFileBuffers);
209 
210   static Expected<std::unique_ptr<BinaryCoverageReader>>
211   createCoverageReaderFromBuffer(StringRef Coverage,
212                                  InstrProfSymtab &&ProfileNames,
213                                  uint8_t BytesInAddress,
214                                  support::endianness Endian);
215 
216   Error readNextRecord(CoverageMappingRecord &Record) override;
217 };
218 
219 } // end namespace coverage
220 } // end namespace llvm
221 
222 #endif // LLVM_PROFILEDATA_COVERAGE_COVERAGEMAPPINGREADER_H
223