lib/ProfileData/SampleProf.cpp

   1 //=-- SampleProf.cpp - Sample profiling format support --------------------===//
   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 common definitions used in the reading and writing of
  10 // sample profile data.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "llvm/ProfileData/SampleProf.h"
  15 #include "llvm/Config/llvm-config.h"
  16 #include "llvm/IR/DebugInfoMetadata.h"
  17 #include "llvm/Support/Compiler.h"
  18 #include "llvm/Support/Compression.h"
  19 #include "llvm/Support/Debug.h"
  20 #include "llvm/Support/Error.h"
  21 #include "llvm/Support/ErrorHandling.h"
  22 #include "llvm/Support/LEB128.h"
  23 #include "llvm/Support/ManagedStatic.h"
  24 #include "llvm/Support/raw_ostream.h"
  25 #include <string>
  26 #include <system_error>
  27
  28 using namespace llvm;
  29 using namespace sampleprof;
  30
  31 namespace llvm {
  32 namespace sampleprof {
  33 SampleProfileFormat FunctionSamples::Format;
  34 } // namespace sampleprof
  35 } // namespace llvm
  36
  37 namespace {
  38
  39 // FIXME: This class is only here to support the transition to llvm::Error. It
  40 // will be removed once this transition is complete. Clients should prefer to
  41 // deal with the Error value directly, rather than converting to error_code.
  42 class SampleProfErrorCategoryType : public std::error_category {
  43   const char *name() const noexcept override { return "llvm.sampleprof"; }
  44
  45   std::string message(int IE) const override {
  46     sampleprof_error E = static_cast<sampleprof_error>(IE);
  47     switch (E) {
  48     case sampleprof_error::success:
  49       return "Success";
  50     case sampleprof_error::bad_magic:
  51       return "Invalid sample profile data (bad magic)";
  52     case sampleprof_error::unsupported_version:
  53       return "Unsupported sample profile format version";
  54     case sampleprof_error::too_large:
  55       return "Too much profile data";
  56     case sampleprof_error::truncated:
  57       return "Truncated profile data";
  58     case sampleprof_error::malformed:
  59       return "Malformed sample profile data";
  60     case sampleprof_error::unrecognized_format:
  61       return "Unrecognized sample profile encoding format";
  62     case sampleprof_error::unsupported_writing_format:
  63       return "Profile encoding format unsupported for writing operations";
  64     case sampleprof_error::truncated_name_table:
  65       return "Truncated function name table";
  66     case sampleprof_error::not_implemented:
  67       return "Unimplemented feature";
  68     case sampleprof_error::counter_overflow:
  69       return "Counter overflow";
  70     case sampleprof_error::ostream_seek_unsupported:
  71       return "Ostream does not support seek";
  72     case sampleprof_error::compress_failed:
  73       return "Compress failure";
  74     case sampleprof_error::uncompress_failed:
  75       return "Uncompress failure";
  76     case sampleprof_error::zlib_unavailable:
  77       return "Zlib is unavailable";
  78     }
  79     llvm_unreachable("A value of sampleprof_error has no message.");
  80   }
  81 };
  82
  83 } // end anonymous namespace
  84
  85 static ManagedStatic<SampleProfErrorCategoryType> ErrorCategory;
  86
  87 const std::error_category &llvm::sampleprof_category() {
  88   return *ErrorCategory;
  89 }
  90
  91 void LineLocation::print(raw_ostream &OS) const {
  92   OS << LineOffset;
  93   if (Discriminator > 0)
  94     OS << "." << Discriminator;
  95 }
  96
  97 raw_ostream &llvm::sampleprof::operator<<(raw_ostream &OS,
  98                                           const LineLocation &Loc) {
  99   Loc.print(OS);
 100   return OS;
 101 }
 102
 103 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
 104 LLVM_DUMP_METHOD void LineLocation::dump() const { print(dbgs()); }
 105 #endif
 106
 107 /// Print the sample record to the stream \p OS indented by \p Indent.
 108 void SampleRecord::print(raw_ostream &OS, unsigned Indent) const {
 109   OS << NumSamples;
 110   if (hasCalls()) {
 111     OS << ", calls:";
 112     for (const auto &I : getSortedCallTargets())
 113       OS << " " << I.first << ":" << I.second;
 114   }
 115   OS << "\n";
 116 }
 117
 118 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
 119 LLVM_DUMP_METHOD void SampleRecord::dump() const { print(dbgs(), 0); }
 120 #endif
 121
 122 raw_ostream &llvm::sampleprof::operator<<(raw_ostream &OS,
 123                                           const SampleRecord &Sample) {
 124   Sample.print(OS, 0);
 125   return OS;
 126 }
 127
 128 /// Print the samples collected for a function on stream \p OS.
 129 void FunctionSamples::print(raw_ostream &OS, unsigned Indent) const {
 130   OS << TotalSamples << ", " << TotalHeadSamples << ", " << BodySamples.size()
 131      << " sampled lines\n";
 132
 133   OS.indent(Indent);
 134   if (!BodySamples.empty()) {
 135     OS << "Samples collected in the function's body {\n";
 136     SampleSorter<LineLocation, SampleRecord> SortedBodySamples(BodySamples);
 137     for (const auto &SI : SortedBodySamples.get()) {
 138       OS.indent(Indent + 2);
 139       OS << SI->first << ": " << SI->second;
 140     }
 141     OS.indent(Indent);
 142     OS << "}\n";
 143   } else {
 144     OS << "No samples collected in the function's body\n";
 145   }
 146
 147   OS.indent(Indent);
 148   if (!CallsiteSamples.empty()) {
 149     OS << "Samples collected in inlined callsites {\n";
 150     SampleSorter<LineLocation, FunctionSamplesMap> SortedCallsiteSamples(
 151         CallsiteSamples);
 152     for (const auto &CS : SortedCallsiteSamples.get()) {
 153       for (const auto &FS : CS->second) {
 154         OS.indent(Indent + 2);
 155         OS << CS->first << ": inlined callee: " << FS.second.getName() << ": ";
 156         FS.second.print(OS, Indent + 4);
 157       }
 158     }
 159     OS << "}\n";
 160   } else {
 161     OS << "No inlined callsites in this function\n";
 162   }
 163 }
 164
 165 raw_ostream &llvm::sampleprof::operator<<(raw_ostream &OS,
 166                                           const FunctionSamples &FS) {
 167   FS.print(OS);
 168   return OS;
 169 }
 170
 171 unsigned FunctionSamples::getOffset(const DILocation *DIL) {
 172   return (DIL->getLine() - DIL->getScope()->getSubprogram()->getLine()) &
 173       0xffff;
 174 }
 175
 176 const FunctionSamples *
 177 FunctionSamples::findFunctionSamples(const DILocation *DIL) const {
 178   assert(DIL);
 179   SmallVector<std::pair<LineLocation, StringRef>, 10> S;
 180
 181   const DILocation *PrevDIL = DIL;
 182   for (DIL = DIL->getInlinedAt(); DIL; DIL = DIL->getInlinedAt()) {
 183     S.push_back(std::make_pair(
 184         LineLocation(getOffset(DIL), DIL->getBaseDiscriminator()),
 185         PrevDIL->getScope()->getSubprogram()->getLinkageName()));
 186     PrevDIL = DIL;
 187   }
 188   if (S.size() == 0)
 189     return this;
 190   const FunctionSamples *FS = this;
 191   for (int i = S.size() - 1; i >= 0 && FS != nullptr; i--) {
 192     FS = FS->findFunctionSamplesAt(S[i].first, S[i].second);
 193   }
 194   return FS;
 195 }
 196
 197 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
 198 LLVM_DUMP_METHOD void FunctionSamples::dump() const { print(dbgs(), 0); }
 199 #endif
 200
 201 std::error_code ProfileSymbolList::read(uint64_t CompressSize,
 202                                         uint64_t UncompressSize,
 203                                         const uint8_t *Data) {
 204   const char *ListStart = reinterpret_cast<const char *>(Data);
 205   // CompressSize being non-zero means the profile is compressed and
 206   // needs to be uncompressed first.
 207   if (CompressSize) {
 208     if (!llvm::zlib::isAvailable())
 209       return sampleprof_error::zlib_unavailable;
 210
 211     StringRef CompressedStrings(reinterpret_cast<const char *>(Data),
 212                                 CompressSize);
 213     char *Buffer = Allocator.Allocate<char>(UncompressSize);
 214     size_t UCSize = UncompressSize;
 215     llvm::Error E = zlib::uncompress(CompressedStrings, Buffer, UCSize);
 216     if (E)
 217       return sampleprof_error::uncompress_failed;
 218     ListStart = Buffer;
 219   }
 220
 221   uint64_t Size = 0;
 222   while (Size < UncompressSize) {
 223     StringRef Str(ListStart + Size);
 224     add(Str);
 225     Size += Str.size() + 1;
 226   }
 227   return sampleprof_error::success;
 228 }
 229
 230 std::error_code ProfileSymbolList::write(raw_ostream &OS) {
 231   // Sort the symbols before doing compression. It will make the
 232   // compression much more effective.
 233   std::vector<StringRef> SortedList;
 234   SortedList.insert(SortedList.begin(), Syms.begin(), Syms.end());
 235   llvm::sort(SortedList);
 236
 237   std::string UncompressedStrings;
 238   for (auto &Sym : SortedList) {
 239     UncompressedStrings.append(Sym.str());
 240     UncompressedStrings.append(1, '\0');
 241   }
 242
 243   if (ToCompress) {
 244     if (!llvm::zlib::isAvailable())
 245       return sampleprof_error::zlib_unavailable;
 246     SmallString<128> CompressedStrings;
 247     llvm::Error E = zlib::compress(UncompressedStrings, CompressedStrings,
 248                                    zlib::BestSizeCompression);
 249     if (E)
 250       return sampleprof_error::compress_failed;
 251     encodeULEB128(UncompressedStrings.size(), OS);
 252     encodeULEB128(CompressedStrings.size(), OS);
 253     OS << CompressedStrings.str();
 254   } else {
 255     encodeULEB128(UncompressedStrings.size(), OS);
 256     // If profile symbol list is not compressed, we will still save
 257     // a compressed size value, but the value of the size is 0.
 258     encodeULEB128(0, OS);
 259     OS << UncompressedStrings;
 260   }
 261   return sampleprof_error::success;
 262 }
 263
 264 void ProfileSymbolList::dump(raw_ostream &OS) const {
 265   OS << "======== Dump profile symbol list ========\n";
 266   std::vector<StringRef> SortedList;
 267   SortedList.insert(SortedList.begin(), Syms.begin(), Syms.end());
 268   llvm::sort(SortedList);
 269
 270   for (auto &Sym : SortedList)
 271     OS << Sym << "\n";
 272 }