1//===- SampleProfWriter.cpp - Write LLVM sample profile data --------------===//
2//
3//                      The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file implements the class that writes LLVM sample profiles. It
11// supports two file formats: text and binary. The textual representation
12// is useful for debugging and testing purposes. The binary representation
13// is more compact, resulting in smaller file sizes. However, they can
14// both be used interchangeably.
15//
16// See lib/ProfileData/SampleProfReader.cpp for documentation on each of the
17// supported formats.
18//
19//===----------------------------------------------------------------------===//
20
21#include "llvm/ProfileData/SampleProfWriter.h"
22#include "llvm/Support/Debug.h"
23#include "llvm/Support/ErrorOr.h"
24#include "llvm/Support/LEB128.h"
25#include "llvm/Support/LineIterator.h"
26#include "llvm/Support/MemoryBuffer.h"
27#include "llvm/Support/Regex.h"
28
29using namespace llvm::sampleprof;
30using namespace llvm;
31
32/// \brief Write samples to a text file.
33///
34/// Note: it may be tempting to implement this in terms of
35/// FunctionSamples::print().  Please don't.  The dump functionality is intended
36/// for debugging and has no specified form.
37///
38/// The format used here is more structured and deliberate because
39/// it needs to be parsed by the SampleProfileReaderText class.
40std::error_code SampleProfileWriterText::write(const FunctionSamples &S) {
41  auto &OS = *OutputStream;
42  OS << S.getName() << ":" << S.getTotalSamples();
43  if (Indent == 0)
44    OS << ":" << S.getHeadSamples();
45  OS << "\n";
46
47  SampleSorter<LineLocation, SampleRecord> SortedSamples(S.getBodySamples());
48  for (const auto &I : SortedSamples.get()) {
49    LineLocation Loc = I->first;
50    const SampleRecord &Sample = I->second;
51    OS.indent(Indent + 1);
52    if (Loc.Discriminator == 0)
53      OS << Loc.LineOffset << ": ";
54    else
55      OS << Loc.LineOffset << "." << Loc.Discriminator << ": ";
56
57    OS << Sample.getSamples();
58
59    for (const auto &J : Sample.getCallTargets())
60      OS << " " << J.first() << ":" << J.second;
61    OS << "\n";
62  }
63
64  SampleSorter<LineLocation, FunctionSamples> SortedCallsiteSamples(
65      S.getCallsiteSamples());
66  Indent += 1;
67  for (const auto &I : SortedCallsiteSamples.get()) {
68    LineLocation Loc = I->first;
69    const FunctionSamples &CalleeSamples = I->second;
70    OS.indent(Indent);
71    if (Loc.Discriminator == 0)
72      OS << Loc.LineOffset << ": ";
73    else
74      OS << Loc.LineOffset << "." << Loc.Discriminator << ": ";
75    if (std::error_code EC = write(CalleeSamples))
76      return EC;
77  }
78  Indent -= 1;
79
80  return sampleprof_error::success;
81}
82
83std::error_code SampleProfileWriterBinary::writeNameIdx(StringRef FName) {
84  const auto &ret = NameTable.find(FName);
85  if (ret == NameTable.end())
86    return sampleprof_error::truncated_name_table;
87  encodeULEB128(ret->second, *OutputStream);
88  return sampleprof_error::success;
89}
90
91void SampleProfileWriterBinary::addName(StringRef FName) {
92  auto NextIdx = NameTable.size();
93  NameTable.insert(std::make_pair(FName, NextIdx));
94}
95
96void SampleProfileWriterBinary::addNames(const FunctionSamples &S) {
97  // Add all the names in indirect call targets.
98  for (const auto &I : S.getBodySamples()) {
99    const SampleRecord &Sample = I.second;
100    for (const auto &J : Sample.getCallTargets())
101      addName(J.first());
102  }
103
104  // Recursively add all the names for inlined callsites.
105  for (const auto &J : S.getCallsiteSamples()) {
106    const FunctionSamples &CalleeSamples = J.second;
107    addName(CalleeSamples.getName());
108    addNames(CalleeSamples);
109  }
110}
111
112std::error_code SampleProfileWriterBinary::writeHeader(
113    const StringMap<FunctionSamples> &ProfileMap) {
114  auto &OS = *OutputStream;
115
116  // Write file magic identifier.
117  encodeULEB128(SPMagic(), OS);
118  encodeULEB128(SPVersion(), OS);
119
120  computeSummary(ProfileMap);
121  if (auto EC = writeSummary())
122    return EC;
123
124  // Generate the name table for all the functions referenced in the profile.
125  for (const auto &I : ProfileMap) {
126    addName(I.first());
127    addNames(I.second);
128  }
129
130  // Write out the name table.
131  encodeULEB128(NameTable.size(), OS);
132  for (auto N : NameTable) {
133    OS << N.first;
134    encodeULEB128(0, OS);
135  }
136  return sampleprof_error::success;
137}
138
139std::error_code SampleProfileWriterBinary::writeSummary() {
140  auto &OS = *OutputStream;
141  encodeULEB128(Summary->getTotalCount(), OS);
142  encodeULEB128(Summary->getMaxCount(), OS);
143  encodeULEB128(Summary->getMaxFunctionCount(), OS);
144  encodeULEB128(Summary->getNumCounts(), OS);
145  encodeULEB128(Summary->getNumFunctions(), OS);
146  std::vector<ProfileSummaryEntry> &Entries = Summary->getDetailedSummary();
147  encodeULEB128(Entries.size(), OS);
148  for (auto Entry : Entries) {
149    encodeULEB128(Entry.Cutoff, OS);
150    encodeULEB128(Entry.MinCount, OS);
151    encodeULEB128(Entry.NumCounts, OS);
152  }
153  return sampleprof_error::success;
154}
155std::error_code SampleProfileWriterBinary::writeBody(const FunctionSamples &S) {
156  auto &OS = *OutputStream;
157
158  if (std::error_code EC = writeNameIdx(S.getName()))
159    return EC;
160
161  encodeULEB128(S.getTotalSamples(), OS);
162
163  // Emit all the body samples.
164  encodeULEB128(S.getBodySamples().size(), OS);
165  for (const auto &I : S.getBodySamples()) {
166    LineLocation Loc = I.first;
167    const SampleRecord &Sample = I.second;
168    encodeULEB128(Loc.LineOffset, OS);
169    encodeULEB128(Loc.Discriminator, OS);
170    encodeULEB128(Sample.getSamples(), OS);
171    encodeULEB128(Sample.getCallTargets().size(), OS);
172    for (const auto &J : Sample.getCallTargets()) {
173      StringRef Callee = J.first();
174      uint64_t CalleeSamples = J.second;
175      if (std::error_code EC = writeNameIdx(Callee))
176        return EC;
177      encodeULEB128(CalleeSamples, OS);
178    }
179  }
180
181  // Recursively emit all the callsite samples.
182  encodeULEB128(S.getCallsiteSamples().size(), OS);
183  for (const auto &J : S.getCallsiteSamples()) {
184    LineLocation Loc = J.first;
185    const FunctionSamples &CalleeSamples = J.second;
186    encodeULEB128(Loc.LineOffset, OS);
187    encodeULEB128(Loc.Discriminator, OS);
188    if (std::error_code EC = writeBody(CalleeSamples))
189      return EC;
190  }
191
192  return sampleprof_error::success;
193}
194
195/// \brief Write samples of a top-level function to a binary file.
196///
197/// \returns true if the samples were written successfully, false otherwise.
198std::error_code SampleProfileWriterBinary::write(const FunctionSamples &S) {
199  encodeULEB128(S.getHeadSamples(), *OutputStream);
200  return writeBody(S);
201}
202
203/// \brief Create a sample profile file writer based on the specified format.
204///
205/// \param Filename The file to create.
206///
207/// \param Writer The writer to instantiate according to the specified format.
208///
209/// \param Format Encoding format for the profile file.
210///
211/// \returns an error code indicating the status of the created writer.
212ErrorOr<std::unique_ptr<SampleProfileWriter>>
213SampleProfileWriter::create(StringRef Filename, SampleProfileFormat Format) {
214  std::error_code EC;
215  std::unique_ptr<raw_ostream> OS;
216  if (Format == SPF_Binary)
217    OS.reset(new raw_fd_ostream(Filename, EC, sys::fs::F_None));
218  else
219    OS.reset(new raw_fd_ostream(Filename, EC, sys::fs::F_Text));
220  if (EC)
221    return EC;
222
223  return create(OS, Format);
224}
225
226/// \brief Create a sample profile stream writer based on the specified format.
227///
228/// \param OS The output stream to store the profile data to.
229///
230/// \param Writer The writer to instantiate according to the specified format.
231///
232/// \param Format Encoding format for the profile file.
233///
234/// \returns an error code indicating the status of the created writer.
235ErrorOr<std::unique_ptr<SampleProfileWriter>>
236SampleProfileWriter::create(std::unique_ptr<raw_ostream> &OS,
237                            SampleProfileFormat Format) {
238  std::error_code EC;
239  std::unique_ptr<SampleProfileWriter> Writer;
240
241  if (Format == SPF_Binary)
242    Writer.reset(new SampleProfileWriterBinary(OS));
243  else if (Format == SPF_Text)
244    Writer.reset(new SampleProfileWriterText(OS));
245  else if (Format == SPF_GCC)
246    EC = sampleprof_error::unsupported_writing_format;
247  else
248    EC = sampleprof_error::unrecognized_format;
249
250  if (EC)
251    return EC;
252
253  return std::move(Writer);
254}
255
256void SampleProfileWriter::computeSummary(
257    const StringMap<FunctionSamples> &ProfileMap) {
258  SampleProfileSummaryBuilder Builder(ProfileSummaryBuilder::DefaultCutoffs);
259  for (const auto &I : ProfileMap) {
260    const FunctionSamples &Profile = I.second;
261    Builder.addRecord(Profile);
262  }
263  Summary = Builder.getSummary();
264}
265