xref: /freebsd/contrib/llvm-project/llvm/include/llvm/ProfileData/Coverage/CoverageMappingReader.h (revision 700637cbb5e582861067a11aaca4d053546871d2)
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/Compiler.h"
22 #include "llvm/Support/Error.h"
23 #include "llvm/Support/MemoryBuffer.h"
24 #include <cstddef>
25 #include <cstdint>
26 #include <iterator>
27 #include <memory>
28 #include <vector>
29 
30 namespace llvm {
31 namespace coverage {
32 
33 class CoverageMappingReader;
34 
35 /// Coverage mapping information for a single function.
36 struct CoverageMappingRecord {
37   StringRef FunctionName;
38   uint64_t FunctionHash;
39   ArrayRef<StringRef> Filenames;
40   ArrayRef<CounterExpression> Expressions;
41   ArrayRef<CounterMappingRegion> MappingRegions;
42 };
43 
44 /// A file format agnostic iterator over coverage mapping data.
45 class CoverageMappingIterator {
46   CoverageMappingReader *Reader;
47   CoverageMappingRecord Record;
48   coveragemap_error ReadErr;
49 
50   LLVM_ABI void increment();
51 
52 public:
53   using iterator_category = std::input_iterator_tag;
54   using value_type = CoverageMappingRecord;
55   using difference_type = std::ptrdiff_t;
56   using pointer = value_type *;
57   using reference = value_type &;
58 
CoverageMappingIterator()59   CoverageMappingIterator()
60       : Reader(nullptr), ReadErr(coveragemap_error::success) {}
61 
CoverageMappingIterator(CoverageMappingReader * Reader)62   CoverageMappingIterator(CoverageMappingReader *Reader)
63       : Reader(Reader), ReadErr(coveragemap_error::success) {
64     increment();
65   }
66 
~CoverageMappingIterator()67   ~CoverageMappingIterator() {
68     if (ReadErr != coveragemap_error::success)
69       llvm_unreachable("Unexpected error in coverage mapping iterator");
70   }
71 
72   CoverageMappingIterator &operator++() {
73     increment();
74     return *this;
75   }
76   bool operator==(const CoverageMappingIterator &RHS) const {
77     return Reader == RHS.Reader;
78   }
79   bool operator!=(const CoverageMappingIterator &RHS) const {
80     return Reader != RHS.Reader;
81   }
82   Expected<CoverageMappingRecord &> operator*() {
83     if (ReadErr != coveragemap_error::success) {
84       auto E = make_error<CoverageMapError>(ReadErr);
85       ReadErr = coveragemap_error::success;
86       return std::move(E);
87     }
88     return Record;
89   }
90   Expected<CoverageMappingRecord *> operator->() {
91     if (ReadErr != coveragemap_error::success) {
92       auto E = make_error<CoverageMapError>(ReadErr);
93       ReadErr = coveragemap_error::success;
94       return std::move(E);
95     }
96     return &Record;
97   }
98 };
99 
100 class CoverageMappingReader {
101 public:
102   virtual ~CoverageMappingReader() = default;
103 
104   virtual Error readNextRecord(CoverageMappingRecord &Record) = 0;
begin()105   CoverageMappingIterator begin() { return CoverageMappingIterator(this); }
end()106   CoverageMappingIterator end() { return CoverageMappingIterator(); }
107 };
108 
109 /// Base class for the raw coverage mapping and filenames data readers.
110 class RawCoverageReader {
111 protected:
112   StringRef Data;
113 
RawCoverageReader(StringRef Data)114   RawCoverageReader(StringRef Data) : Data(Data) {}
115 
116   LLVM_ABI Error readULEB128(uint64_t &Result);
117   LLVM_ABI Error readIntMax(uint64_t &Result, uint64_t MaxPlus1);
118   LLVM_ABI Error readSize(uint64_t &Result);
119   LLVM_ABI Error readString(StringRef &Result);
120 };
121 
122 /// Checks if the given coverage mapping data is exported for
123 /// an unused function.
124 class RawCoverageMappingDummyChecker : public RawCoverageReader {
125 public:
RawCoverageMappingDummyChecker(StringRef MappingData)126   RawCoverageMappingDummyChecker(StringRef MappingData)
127       : RawCoverageReader(MappingData) {}
128 
129   LLVM_ABI Expected<bool> isDummy();
130 };
131 
132 /// Reader for the raw coverage mapping data.
133 class RawCoverageMappingReader : public RawCoverageReader {
134   ArrayRef<std::string> &TranslationUnitFilenames;
135   std::vector<StringRef> &Filenames;
136   std::vector<CounterExpression> &Expressions;
137   std::vector<CounterMappingRegion> &MappingRegions;
138 
139 public:
RawCoverageMappingReader(StringRef MappingData,ArrayRef<std::string> & TranslationUnitFilenames,std::vector<StringRef> & Filenames,std::vector<CounterExpression> & Expressions,std::vector<CounterMappingRegion> & MappingRegions)140   RawCoverageMappingReader(StringRef MappingData,
141                            ArrayRef<std::string> &TranslationUnitFilenames,
142                            std::vector<StringRef> &Filenames,
143                            std::vector<CounterExpression> &Expressions,
144                            std::vector<CounterMappingRegion> &MappingRegions)
145       : RawCoverageReader(MappingData),
146         TranslationUnitFilenames(TranslationUnitFilenames),
147         Filenames(Filenames), Expressions(Expressions),
148         MappingRegions(MappingRegions) {}
149   RawCoverageMappingReader(const RawCoverageMappingReader &) = delete;
150   RawCoverageMappingReader &
151   operator=(const RawCoverageMappingReader &) = delete;
152 
153   LLVM_ABI Error read();
154 
155 private:
156   Error decodeCounter(unsigned Value, Counter &C);
157   Error readCounter(Counter &C);
158   Error
159   readMappingRegionsSubArray(std::vector<CounterMappingRegion> &MappingRegions,
160                              unsigned InferredFileID, size_t NumFileIDs);
161 };
162 
163 /// Reader for the coverage mapping data that is emitted by the
164 /// frontend and stored in an object file.
165 class LLVM_ABI BinaryCoverageReader : public CoverageMappingReader {
166 public:
167   struct ProfileMappingRecord {
168     CovMapVersion Version;
169     StringRef FunctionName;
170     uint64_t FunctionHash;
171     StringRef CoverageMapping;
172     size_t FilenamesBegin;
173     size_t FilenamesSize;
174 
ProfileMappingRecordProfileMappingRecord175     ProfileMappingRecord(CovMapVersion Version, StringRef FunctionName,
176                          uint64_t FunctionHash, StringRef CoverageMapping,
177                          size_t FilenamesBegin, size_t FilenamesSize)
178         : Version(Version), FunctionName(FunctionName),
179           FunctionHash(FunctionHash), CoverageMapping(CoverageMapping),
180           FilenamesBegin(FilenamesBegin), FilenamesSize(FilenamesSize) {}
181   };
182 
183   using FuncRecordsStorage = std::unique_ptr<MemoryBuffer>;
184   using CoverageMapCopyStorage = std::unique_ptr<MemoryBuffer>;
185 
186 private:
187   std::vector<std::string> Filenames;
188   std::vector<ProfileMappingRecord> MappingRecords;
189   std::unique_ptr<InstrProfSymtab> ProfileNames;
190   size_t CurrentRecord = 0;
191   std::vector<StringRef> FunctionsFilenames;
192   std::vector<CounterExpression> Expressions;
193   std::vector<CounterMappingRegion> MappingRegions;
194 
195   // Used to tie the lifetimes of coverage function records to the lifetime of
196   // this BinaryCoverageReader instance. Needed to support the format change in
197   // D69471, which can split up function records into multiple sections on ELF.
198   FuncRecordsStorage FuncRecords;
199 
200   // Used to tie the lifetimes of an optional copy of the coverage mapping data
201   // to the lifetime of this BinaryCoverageReader instance. Needed to support
202   // Wasm object format, which might require realignment of section contents.
203   CoverageMapCopyStorage CoverageMapCopy;
204 
BinaryCoverageReader(std::unique_ptr<InstrProfSymtab> Symtab,FuncRecordsStorage && FuncRecords,CoverageMapCopyStorage && CoverageMapCopy)205   BinaryCoverageReader(std::unique_ptr<InstrProfSymtab> Symtab,
206                        FuncRecordsStorage &&FuncRecords,
207                        CoverageMapCopyStorage &&CoverageMapCopy)
208       : ProfileNames(std::move(Symtab)), FuncRecords(std::move(FuncRecords)),
209         CoverageMapCopy(std::move(CoverageMapCopy)) {}
210 
211 public:
212   BinaryCoverageReader(const BinaryCoverageReader &) = delete;
213   BinaryCoverageReader &operator=(const BinaryCoverageReader &) = delete;
214 
215   static Expected<std::vector<std::unique_ptr<BinaryCoverageReader>>>
216   create(MemoryBufferRef ObjectBuffer, StringRef Arch,
217          SmallVectorImpl<std::unique_ptr<MemoryBuffer>> &ObjectFileBuffers,
218          StringRef CompilationDir = "",
219          SmallVectorImpl<object::BuildIDRef> *BinaryIDs = nullptr);
220 
221   static Expected<std::unique_ptr<BinaryCoverageReader>>
222   createCoverageReaderFromBuffer(
223       StringRef Coverage, FuncRecordsStorage &&FuncRecords,
224       CoverageMapCopyStorage &&CoverageMap,
225       std::unique_ptr<InstrProfSymtab> ProfileNamesPtr, uint8_t BytesInAddress,
226       llvm::endianness Endian, StringRef CompilationDir = "");
227 
228   Error readNextRecord(CoverageMappingRecord &Record) override;
229 };
230 
231 /// Reader for the raw coverage filenames.
232 class RawCoverageFilenamesReader : public RawCoverageReader {
233   std::vector<std::string> &Filenames;
234   StringRef CompilationDir;
235 
236   // Read an uncompressed sequence of filenames.
237   Error readUncompressed(CovMapVersion Version, uint64_t NumFilenames);
238 
239 public:
240   RawCoverageFilenamesReader(StringRef Data,
241                              std::vector<std::string> &Filenames,
242                              StringRef CompilationDir = "")
RawCoverageReader(Data)243       : RawCoverageReader(Data), Filenames(Filenames),
244         CompilationDir(CompilationDir) {}
245   RawCoverageFilenamesReader(const RawCoverageFilenamesReader &) = delete;
246   RawCoverageFilenamesReader &
247   operator=(const RawCoverageFilenamesReader &) = delete;
248 
249   LLVM_ABI Error read(CovMapVersion Version);
250 };
251 
252 } // end namespace coverage
253 } // end namespace llvm
254 
255 #endif // LLVM_PROFILEDATA_COVERAGE_COVERAGEMAPPINGREADER_H
256