1 //===- InstrProfWriter.h - Instrumented profiling writer --------*- 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 writing profiling data for instrumentation
10 // based PGO and coverage.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_PROFILEDATA_INSTRPROFWRITER_H
15 #define LLVM_PROFILEDATA_INSTRPROFWRITER_H
16 
17 #include "llvm/ADT/DenseMap.h"
18 #include "llvm/ADT/StringMap.h"
19 #include "llvm/ProfileData/InstrProf.h"
20 #include "llvm/Support/Endian.h"
21 #include "llvm/Support/Error.h"
22 #include "llvm/Support/MemoryBuffer.h"
23 #include <cstdint>
24 #include <memory>
25 
26 namespace llvm {
27 
28 /// Writer for instrumentation based profile data.
29 class InstrProfRecordWriterTrait;
30 class ProfOStream;
31 class raw_fd_ostream;
32 
33 class InstrProfWriter {
34 public:
35   using ProfilingData = SmallDenseMap<uint64_t, InstrProfRecord>;
36 
37 private:
38   bool Sparse;
39   StringMap<ProfilingData> FunctionData;
40   // An enum describing the attributes of the profile.
41   InstrProfKind ProfileKind = InstrProfKind::Unknown;
42   // Use raw pointer here for the incomplete type object.
43   InstrProfRecordWriterTrait *InfoObj;
44 
45 public:
46   InstrProfWriter(bool Sparse = false);
47   ~InstrProfWriter();
48 
49   StringMap<ProfilingData> &getProfileData() { return FunctionData; }
50 
51   /// Add function counts for the given function. If there are already counts
52   /// for this function and the hash and number of counts match, each counter is
53   /// summed. Optionally scale counts by \p Weight.
54   void addRecord(NamedInstrProfRecord &&I, uint64_t Weight,
55                  function_ref<void(Error)> Warn);
56   void addRecord(NamedInstrProfRecord &&I, function_ref<void(Error)> Warn) {
57     addRecord(std::move(I), 1, Warn);
58   }
59 
60   /// Merge existing function counts from the given writer.
61   void mergeRecordsFromWriter(InstrProfWriter &&IPW,
62                               function_ref<void(Error)> Warn);
63 
64   /// Write the profile to \c OS
65   Error write(raw_fd_ostream &OS);
66 
67   /// Write the profile in text format to \c OS
68   Error writeText(raw_fd_ostream &OS);
69 
70   Error validateRecord(const InstrProfRecord &Func);
71 
72   /// Write \c Record in text format to \c OS
73   static void writeRecordInText(StringRef Name, uint64_t Hash,
74                                 const InstrProfRecord &Counters,
75                                 InstrProfSymtab &Symtab, raw_fd_ostream &OS);
76 
77   /// Write the profile, returning the raw data. For testing.
78   std::unique_ptr<MemoryBuffer> writeBuffer();
79 
80   /// Update the attributes of the current profile from the attributes
81   /// specified. An error is returned if IR and FE profiles are mixed.
82   Error mergeProfileKind(const InstrProfKind Other) {
83     // If the kind is unset, this is the first profile we are merging so just
84     // set it to the given type.
85     if (ProfileKind == InstrProfKind::Unknown) {
86       ProfileKind = Other;
87       return Error::success();
88     }
89 
90     // Returns true if merging is should fail assuming A and B are incompatible.
91     auto testIncompatible = [&](InstrProfKind A, InstrProfKind B) {
92       return (static_cast<bool>(ProfileKind & A) &&
93               static_cast<bool>(Other & B)) ||
94              (static_cast<bool>(ProfileKind & B) &&
95               static_cast<bool>(Other & A));
96     };
97 
98     // Check if the profiles are in-compatible. Clang frontend profiles can't be
99     // merged with other profile types.
100     if (static_cast<bool>((ProfileKind & InstrProfKind::FE) ^
101                           (Other & InstrProfKind::FE))) {
102       return make_error<InstrProfError>(instrprof_error::unsupported_version);
103     }
104     if (testIncompatible(InstrProfKind::FunctionEntryOnly, InstrProfKind::BB)) {
105       return make_error<InstrProfError>(
106           instrprof_error::unsupported_version,
107           "cannot merge FunctionEntryOnly profiles and BB profiles together");
108     }
109 
110     // Now we update the profile type with the bits that are set.
111     ProfileKind |= Other;
112     return Error::success();
113   }
114 
115   // Internal interface for testing purpose only.
116   void setValueProfDataEndianness(support::endianness Endianness);
117   void setOutputSparse(bool Sparse);
118   // Compute the overlap b/w this object and Other. Program level result is
119   // stored in Overlap and function level result is stored in FuncLevelOverlap.
120   void overlapRecord(NamedInstrProfRecord &&Other, OverlapStats &Overlap,
121                      OverlapStats &FuncLevelOverlap,
122                      const OverlapFuncFilters &FuncFilter);
123 
124 private:
125   void addRecord(StringRef Name, uint64_t Hash, InstrProfRecord &&I,
126                  uint64_t Weight, function_ref<void(Error)> Warn);
127   bool shouldEncodeData(const ProfilingData &PD);
128 
129   Error writeImpl(ProfOStream &OS);
130 };
131 
132 } // end namespace llvm
133 
134 #endif // LLVM_PROFILEDATA_INSTRPROFWRITER_H
135