1 //===- SampleProfWriter.cpp - Write LLVM sample profile data --------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
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.
16 // See lib/ProfileData/SampleProfReader.cpp for documentation on each of the
19 //===----------------------------------------------------------------------===//
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"
29 using namespace llvm::sampleprof;
32 /// \brief Write samples to a text file.
33 std::error_code SampleProfileWriterText::write(StringRef FName,
34 const FunctionSamples &S) {
35 OS << FName << ":" << S.getTotalSamples();
37 OS << ":" << S.getHeadSamples();
40 for (const auto &I : S.getBodySamples()) {
41 LineLocation Loc = I.first;
42 const SampleRecord &Sample = I.second;
43 OS.indent(Indent + 1);
44 if (Loc.Discriminator == 0)
45 OS << Loc.LineOffset << ": ";
47 OS << Loc.LineOffset << "." << Loc.Discriminator << ": ";
49 OS << Sample.getSamples();
51 for (const auto &J : Sample.getCallTargets())
52 OS << " " << J.first() << ":" << J.second;
57 for (const auto &I : S.getCallsiteSamples()) {
58 CallsiteLocation Loc = I.first;
59 const FunctionSamples &CalleeSamples = I.second;
61 if (Loc.Discriminator == 0)
62 OS << Loc.LineOffset << ": ";
64 OS << Loc.LineOffset << "." << Loc.Discriminator << ": ";
65 if (std::error_code EC = write(Loc.CalleeName, CalleeSamples))
70 return sampleprof_error::success;
73 std::error_code SampleProfileWriterBinary::writeNameIdx(StringRef FName) {
74 const auto &ret = NameTable.find(FName);
75 if (ret == NameTable.end())
76 return sampleprof_error::truncated_name_table;
77 encodeULEB128(ret->second, OS);
78 return sampleprof_error::success;
81 void SampleProfileWriterBinary::addName(StringRef FName) {
82 auto NextIdx = NameTable.size();
83 NameTable.insert(std::make_pair(FName, NextIdx));
86 void SampleProfileWriterBinary::addNames(const FunctionSamples &S) {
87 // Add all the names in indirect call targets.
88 for (const auto &I : S.getBodySamples()) {
89 const SampleRecord &Sample = I.second;
90 for (const auto &J : Sample.getCallTargets())
94 // Recursively add all the names for inlined callsites.
95 for (const auto &J : S.getCallsiteSamples()) {
96 CallsiteLocation Loc = J.first;
97 const FunctionSamples &CalleeSamples = J.second;
98 addName(Loc.CalleeName);
99 addNames(CalleeSamples);
103 std::error_code SampleProfileWriterBinary::writeHeader(
104 const StringMap<FunctionSamples> &ProfileMap) {
105 // Write file magic identifier.
106 encodeULEB128(SPMagic(), OS);
107 encodeULEB128(SPVersion(), OS);
109 // Generate the name table for all the functions referenced in the profile.
110 for (const auto &I : ProfileMap) {
115 // Write out the name table.
116 encodeULEB128(NameTable.size(), OS);
117 for (auto N : NameTable) {
119 encodeULEB128(0, OS);
122 return sampleprof_error::success;
125 /// \brief Write samples to a binary file.
127 /// \returns true if the samples were written successfully, false otherwise.
128 std::error_code SampleProfileWriterBinary::write(StringRef FName,
129 const FunctionSamples &S) {
130 if (std::error_code EC = writeNameIdx(FName))
133 encodeULEB128(S.getTotalSamples(), OS);
134 encodeULEB128(S.getHeadSamples(), OS);
135 encodeULEB128(S.getBodySamples().size(), OS);
137 // Emit all the body samples.
138 for (const auto &I : S.getBodySamples()) {
139 LineLocation Loc = I.first;
140 const SampleRecord &Sample = I.second;
141 encodeULEB128(Loc.LineOffset, OS);
142 encodeULEB128(Loc.Discriminator, OS);
143 encodeULEB128(Sample.getSamples(), OS);
144 encodeULEB128(Sample.getCallTargets().size(), OS);
145 for (const auto &J : Sample.getCallTargets()) {
146 StringRef Callee = J.first();
147 uint64_t CalleeSamples = J.second;
148 if (std::error_code EC = writeNameIdx(Callee))
150 encodeULEB128(CalleeSamples, OS);
154 // Recursively emit all the callsite samples.
155 encodeULEB128(S.getCallsiteSamples().size(), OS);
156 for (const auto &J : S.getCallsiteSamples()) {
157 CallsiteLocation Loc = J.first;
158 const FunctionSamples &CalleeSamples = J.second;
159 encodeULEB128(Loc.LineOffset, OS);
160 encodeULEB128(Loc.Discriminator, OS);
161 if (std::error_code EC = write(Loc.CalleeName, CalleeSamples))
165 return sampleprof_error::success;
168 /// \brief Create a sample profile writer based on the specified format.
170 /// \param Filename The file to create.
172 /// \param Writer The writer to instantiate according to the specified format.
174 /// \param Format Encoding format for the profile file.
176 /// \returns an error code indicating the status of the created writer.
177 ErrorOr<std::unique_ptr<SampleProfileWriter>>
178 SampleProfileWriter::create(StringRef Filename, SampleProfileFormat Format) {
180 std::unique_ptr<SampleProfileWriter> Writer;
182 if (Format == SPF_Binary)
183 Writer.reset(new SampleProfileWriterBinary(Filename, EC));
184 else if (Format == SPF_Text)
185 Writer.reset(new SampleProfileWriterText(Filename, EC));
186 else if (Format == SPF_GCC)
187 EC = sampleprof_error::unsupported_writing_format;
189 EC = sampleprof_error::unrecognized_format;
194 return std::move(Writer);