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/ProfileData/SampleProfReader.h"
18 #include "llvm/Support/Compiler.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 bool FunctionSamples::ProfileIsCS = false;
35 bool FunctionSamples::UseMD5;
36 } // namespace sampleprof
37 } // namespace llvm
38 
39 namespace {
40 
41 // FIXME: This class is only here to support the transition to llvm::Error. It
42 // will be removed once this transition is complete. Clients should prefer to
43 // deal with the Error value directly, rather than converting to error_code.
44 class SampleProfErrorCategoryType : public std::error_category {
45   const char *name() const noexcept override { return "llvm.sampleprof"; }
46 
47   std::string message(int IE) const override {
48     sampleprof_error E = static_cast<sampleprof_error>(IE);
49     switch (E) {
50     case sampleprof_error::success:
51       return "Success";
52     case sampleprof_error::bad_magic:
53       return "Invalid sample profile data (bad magic)";
54     case sampleprof_error::unsupported_version:
55       return "Unsupported sample profile format version";
56     case sampleprof_error::too_large:
57       return "Too much profile data";
58     case sampleprof_error::truncated:
59       return "Truncated profile data";
60     case sampleprof_error::malformed:
61       return "Malformed sample profile data";
62     case sampleprof_error::unrecognized_format:
63       return "Unrecognized sample profile encoding format";
64     case sampleprof_error::unsupported_writing_format:
65       return "Profile encoding format unsupported for writing operations";
66     case sampleprof_error::truncated_name_table:
67       return "Truncated function name table";
68     case sampleprof_error::not_implemented:
69       return "Unimplemented feature";
70     case sampleprof_error::counter_overflow:
71       return "Counter overflow";
72     case sampleprof_error::ostream_seek_unsupported:
73       return "Ostream does not support seek";
74     case sampleprof_error::compress_failed:
75       return "Compress failure";
76     case sampleprof_error::uncompress_failed:
77       return "Uncompress failure";
78     case sampleprof_error::zlib_unavailable:
79       return "Zlib is unavailable";
80     }
81     llvm_unreachable("A value of sampleprof_error has no message.");
82   }
83 };
84 
85 } // end anonymous namespace
86 
87 static ManagedStatic<SampleProfErrorCategoryType> ErrorCategory;
88 
89 const std::error_category &llvm::sampleprof_category() {
90   return *ErrorCategory;
91 }
92 
93 void LineLocation::print(raw_ostream &OS) const {
94   OS << LineOffset;
95   if (Discriminator > 0)
96     OS << "." << Discriminator;
97 }
98 
99 raw_ostream &llvm::sampleprof::operator<<(raw_ostream &OS,
100                                           const LineLocation &Loc) {
101   Loc.print(OS);
102   return OS;
103 }
104 
105 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
106 LLVM_DUMP_METHOD void LineLocation::dump() const { print(dbgs()); }
107 #endif
108 
109 /// Print the sample record to the stream \p OS indented by \p Indent.
110 void SampleRecord::print(raw_ostream &OS, unsigned Indent) const {
111   OS << NumSamples;
112   if (hasCalls()) {
113     OS << ", calls:";
114     for (const auto &I : getSortedCallTargets())
115       OS << " " << I.first << ":" << I.second;
116   }
117   OS << "\n";
118 }
119 
120 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
121 LLVM_DUMP_METHOD void SampleRecord::dump() const { print(dbgs(), 0); }
122 #endif
123 
124 raw_ostream &llvm::sampleprof::operator<<(raw_ostream &OS,
125                                           const SampleRecord &Sample) {
126   Sample.print(OS, 0);
127   return OS;
128 }
129 
130 /// Print the samples collected for a function on stream \p OS.
131 void FunctionSamples::print(raw_ostream &OS, unsigned Indent) const {
132   OS << TotalSamples << ", " << TotalHeadSamples << ", " << BodySamples.size()
133      << " sampled lines\n";
134 
135   OS.indent(Indent);
136   if (!BodySamples.empty()) {
137     OS << "Samples collected in the function's body {\n";
138     SampleSorter<LineLocation, SampleRecord> SortedBodySamples(BodySamples);
139     for (const auto &SI : SortedBodySamples.get()) {
140       OS.indent(Indent + 2);
141       OS << SI->first << ": " << SI->second;
142     }
143     OS.indent(Indent);
144     OS << "}\n";
145   } else {
146     OS << "No samples collected in the function's body\n";
147   }
148 
149   OS.indent(Indent);
150   if (!CallsiteSamples.empty()) {
151     OS << "Samples collected in inlined callsites {\n";
152     SampleSorter<LineLocation, FunctionSamplesMap> SortedCallsiteSamples(
153         CallsiteSamples);
154     for (const auto &CS : SortedCallsiteSamples.get()) {
155       for (const auto &FS : CS->second) {
156         OS.indent(Indent + 2);
157         OS << CS->first << ": inlined callee: " << FS.second.getName() << ": ";
158         FS.second.print(OS, Indent + 4);
159       }
160     }
161     OS.indent(Indent);
162     OS << "}\n";
163   } else {
164     OS << "No inlined callsites in this function\n";
165   }
166 }
167 
168 raw_ostream &llvm::sampleprof::operator<<(raw_ostream &OS,
169                                           const FunctionSamples &FS) {
170   FS.print(OS);
171   return OS;
172 }
173 
174 unsigned FunctionSamples::getOffset(const DILocation *DIL) {
175   return (DIL->getLine() - DIL->getScope()->getSubprogram()->getLine()) &
176       0xffff;
177 }
178 
179 const FunctionSamples *FunctionSamples::findFunctionSamples(
180     const DILocation *DIL, SampleProfileReaderItaniumRemapper *Remapper) const {
181   assert(DIL);
182   SmallVector<std::pair<LineLocation, StringRef>, 10> S;
183 
184   const DILocation *PrevDIL = DIL;
185   for (DIL = DIL->getInlinedAt(); DIL; DIL = DIL->getInlinedAt()) {
186     S.push_back(std::make_pair(
187         LineLocation(getOffset(DIL), DIL->getBaseDiscriminator()),
188         PrevDIL->getScope()->getSubprogram()->getLinkageName()));
189     PrevDIL = DIL;
190   }
191   if (S.size() == 0)
192     return this;
193   const FunctionSamples *FS = this;
194   for (int i = S.size() - 1; i >= 0 && FS != nullptr; i--) {
195     FS = FS->findFunctionSamplesAt(S[i].first, S[i].second, Remapper);
196   }
197   return FS;
198 }
199 
200 void FunctionSamples::findAllNames(DenseSet<StringRef> &NameSet) const {
201   NameSet.insert(Name);
202   for (const auto &BS : BodySamples)
203     for (const auto &TS : BS.second.getCallTargets())
204       NameSet.insert(TS.getKey());
205 
206   for (const auto &CS : CallsiteSamples) {
207     for (const auto &NameFS : CS.second) {
208       NameSet.insert(NameFS.first);
209       NameFS.second.findAllNames(NameSet);
210     }
211   }
212 }
213 
214 const FunctionSamples *FunctionSamples::findFunctionSamplesAt(
215     const LineLocation &Loc, StringRef CalleeName,
216     SampleProfileReaderItaniumRemapper *Remapper) const {
217   std::string CalleeGUID;
218   CalleeName = getRepInFormat(CalleeName, UseMD5, CalleeGUID);
219 
220   auto iter = CallsiteSamples.find(Loc);
221   if (iter == CallsiteSamples.end())
222     return nullptr;
223   auto FS = iter->second.find(CalleeName);
224   if (FS != iter->second.end())
225     return &FS->second;
226   if (Remapper) {
227     if (auto NameInProfile = Remapper->lookUpNameInProfile(CalleeName)) {
228       auto FS = iter->second.find(*NameInProfile);
229       if (FS != iter->second.end())
230         return &FS->second;
231     }
232   }
233   // If we cannot find exact match of the callee name, return the FS with
234   // the max total count. Only do this when CalleeName is not provided,
235   // i.e., only for indirect calls.
236   if (!CalleeName.empty())
237     return nullptr;
238   uint64_t MaxTotalSamples = 0;
239   const FunctionSamples *R = nullptr;
240   for (const auto &NameFS : iter->second)
241     if (NameFS.second.getTotalSamples() >= MaxTotalSamples) {
242       MaxTotalSamples = NameFS.second.getTotalSamples();
243       R = &NameFS.second;
244     }
245   return R;
246 }
247 
248 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
249 LLVM_DUMP_METHOD void FunctionSamples::dump() const { print(dbgs(), 0); }
250 #endif
251 
252 std::error_code ProfileSymbolList::read(const uint8_t *Data,
253                                         uint64_t ListSize) {
254   const char *ListStart = reinterpret_cast<const char *>(Data);
255   uint64_t Size = 0;
256   while (Size < ListSize) {
257     StringRef Str(ListStart + Size);
258     add(Str);
259     Size += Str.size() + 1;
260   }
261   if (Size != ListSize)
262     return sampleprof_error::malformed;
263   return sampleprof_error::success;
264 }
265 
266 std::error_code ProfileSymbolList::write(raw_ostream &OS) {
267   // Sort the symbols before output. If doing compression.
268   // It will make the compression much more effective.
269   std::vector<StringRef> SortedList;
270   SortedList.insert(SortedList.begin(), Syms.begin(), Syms.end());
271   llvm::sort(SortedList);
272 
273   std::string OutputString;
274   for (auto &Sym : SortedList) {
275     OutputString.append(Sym.str());
276     OutputString.append(1, '\0');
277   }
278 
279   OS << OutputString;
280   return sampleprof_error::success;
281 }
282 
283 void ProfileSymbolList::dump(raw_ostream &OS) const {
284   OS << "======== Dump profile symbol list ========\n";
285   std::vector<StringRef> SortedList;
286   SortedList.insert(SortedList.begin(), Syms.begin(), Syms.end());
287   llvm::sort(SortedList);
288 
289   for (auto &Sym : SortedList)
290     OS << Sym << "\n";
291 }
292