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/MapVector.h"
19 #include "llvm/ADT/StringMap.h"
20 #include "llvm/IR/GlobalValue.h"
21 #include "llvm/ProfileData/InstrProf.h"
22 #include "llvm/ProfileData/MemProf.h"
23 #include "llvm/Support/Endian.h"
24 #include "llvm/Support/Error.h"
25 #include <cstdint>
26 #include <memory>
27 
28 namespace llvm {
29 
30 /// Writer for instrumentation based profile data.
31 class InstrProfRecordWriterTrait;
32 class ProfOStream;
33 class MemoryBuffer;
34 class raw_fd_ostream;
35 
36 class InstrProfWriter {
37 public:
38   using ProfilingData = SmallDenseMap<uint64_t, InstrProfRecord>;
39 
40 private:
41   bool Sparse;
42   StringMap<ProfilingData> FunctionData;
43 
44   // A map to hold memprof data per function. The lower 64 bits obtained from
45   // the md5 hash of the function name is used to index into the map.
46   llvm::MapVector<GlobalValue::GUID, memprof::MemProfRecord> MemProfData;
47 
48   // An enum describing the attributes of the profile.
49   InstrProfKind ProfileKind = InstrProfKind::Unknown;
50   // Use raw pointer here for the incomplete type object.
51   InstrProfRecordWriterTrait *InfoObj;
52 
53 public:
54   InstrProfWriter(bool Sparse = false);
55   ~InstrProfWriter();
56 
57   StringMap<ProfilingData> &getProfileData() { return FunctionData; }
58 
59   /// Add function counts for the given function. If there are already counts
60   /// for this function and the hash and number of counts match, each counter is
61   /// summed. Optionally scale counts by \p Weight.
62   void addRecord(NamedInstrProfRecord &&I, uint64_t Weight,
63                  function_ref<void(Error)> Warn);
64   void addRecord(NamedInstrProfRecord &&I, function_ref<void(Error)> Warn) {
65     addRecord(std::move(I), 1, Warn);
66   }
67 
68   void addRecord(const GlobalValue::GUID Id,
69                  const memprof::MemProfRecord &Record,
70                  function_ref<void(Error)> Warn);
71 
72   /// Merge existing function counts from the given writer.
73   void mergeRecordsFromWriter(InstrProfWriter &&IPW,
74                               function_ref<void(Error)> Warn);
75 
76   /// Write the profile to \c OS
77   Error write(raw_fd_ostream &OS);
78 
79   /// Write the profile in text format to \c OS
80   Error writeText(raw_fd_ostream &OS);
81 
82   Error validateRecord(const InstrProfRecord &Func);
83 
84   /// Write \c Record in text format to \c OS
85   static void writeRecordInText(StringRef Name, uint64_t Hash,
86                                 const InstrProfRecord &Counters,
87                                 InstrProfSymtab &Symtab, raw_fd_ostream &OS);
88 
89   /// Write the profile, returning the raw data. For testing.
90   std::unique_ptr<MemoryBuffer> writeBuffer();
91 
92   /// Update the attributes of the current profile from the attributes
93   /// specified. An error is returned if IR and FE profiles are mixed.
94   Error mergeProfileKind(const InstrProfKind Other) {
95     // If the kind is unset, this is the first profile we are merging so just
96     // set it to the given type.
97     if (ProfileKind == InstrProfKind::Unknown) {
98       ProfileKind = Other;
99       return Error::success();
100     }
101 
102     // Returns true if merging is should fail assuming A and B are incompatible.
103     auto testIncompatible = [&](InstrProfKind A, InstrProfKind B) {
104       return (static_cast<bool>(ProfileKind & A) &&
105               static_cast<bool>(Other & B)) ||
106              (static_cast<bool>(ProfileKind & B) &&
107               static_cast<bool>(Other & A));
108     };
109 
110     // Check if the profiles are in-compatible. Clang frontend profiles can't be
111     // merged with other profile types.
112     if (static_cast<bool>(
113             (ProfileKind & InstrProfKind::FrontendInstrumentation) ^
114             (Other & InstrProfKind::FrontendInstrumentation))) {
115       return make_error<InstrProfError>(instrprof_error::unsupported_version);
116     }
117     if (testIncompatible(InstrProfKind::FunctionEntryOnly,
118                          InstrProfKind::FunctionEntryInstrumentation)) {
119       return make_error<InstrProfError>(
120           instrprof_error::unsupported_version,
121           "cannot merge FunctionEntryOnly profiles and BB profiles together");
122     }
123 
124     // Now we update the profile type with the bits that are set.
125     ProfileKind |= Other;
126     return Error::success();
127   }
128 
129   InstrProfKind getProfileKind() const { return ProfileKind; }
130 
131   // Internal interface for testing purpose only.
132   void setValueProfDataEndianness(support::endianness Endianness);
133   void setOutputSparse(bool Sparse);
134   // Compute the overlap b/w this object and Other. Program level result is
135   // stored in Overlap and function level result is stored in FuncLevelOverlap.
136   void overlapRecord(NamedInstrProfRecord &&Other, OverlapStats &Overlap,
137                      OverlapStats &FuncLevelOverlap,
138                      const OverlapFuncFilters &FuncFilter);
139 
140 private:
141   void addRecord(StringRef Name, uint64_t Hash, InstrProfRecord &&I,
142                  uint64_t Weight, function_ref<void(Error)> Warn);
143   bool shouldEncodeData(const ProfilingData &PD);
144 
145   Error writeImpl(ProfOStream &OS);
146 };
147 
148 } // end namespace llvm
149 
150 #endif // LLVM_PROFILEDATA_INSTRPROFWRITER_H
151