1 //===- llvm-profgen.cpp - LLVM SPGO profile generation tool -----*- 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 // llvm-profgen generates SPGO profiles from perf script ouput.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "ErrorHandling.h"
14 #include "PerfReader.h"
15 #include "ProfileGenerator.h"
16 #include "ProfiledBinary.h"
17 #include "llvm/DebugInfo/Symbolize/SymbolizableModule.h"
18 #include "llvm/Support/CommandLine.h"
19 #include "llvm/Support/FileSystem.h"
20 #include "llvm/Support/InitLLVM.h"
21 #include "llvm/Support/TargetSelect.h"
22 
23 static cl::OptionCategory ProfGenCategory("ProfGen Options");
24 
25 static cl::opt<std::string> PerfScriptFilename(
26     "perfscript", cl::value_desc("perfscript"), cl::ZeroOrMore,
27     llvm::cl::MiscFlags::CommaSeparated,
28     cl::desc("Path of perf-script trace created by Linux perf tool with "
29              "`script` command(the raw perf.data should be profiled with -b)"),
30     cl::cat(ProfGenCategory));
31 static cl::alias PSA("ps", cl::desc("Alias for --perfscript"),
32                      cl::aliasopt(PerfScriptFilename));
33 
34 static cl::opt<std::string> PerfDataFilename(
35     "perfdata", cl::value_desc("perfdata"), cl::ZeroOrMore,
36     llvm::cl::MiscFlags::CommaSeparated,
37     cl::desc("Path of raw perf data created by Linux perf tool (it should be "
38              "profiled with -b)"),
39     cl::cat(ProfGenCategory));
40 static cl::alias PDA("pd", cl::desc("Alias for --perfdata"),
41                      cl::aliasopt(PerfDataFilename));
42 
43 static cl::opt<std::string> UnsymbolizedProfFilename(
44     "unsymbolized-profile", cl::value_desc("unsymbolized profile"),
45     cl::ZeroOrMore, llvm::cl::MiscFlags::CommaSeparated,
46     cl::desc("Path of the unsymbolized profile created by "
47              "`llvm-profgen` with `--skip-symbolization`"),
48     cl::cat(ProfGenCategory));
49 static cl::alias UPA("up", cl::desc("Alias for --unsymbolized-profile"),
50                      cl::aliasopt(UnsymbolizedProfFilename));
51 
52 static cl::opt<std::string>
53     SampleProfFilename("llvm-sample-profile",
54                        cl::value_desc("llvm sample profile"), cl::ZeroOrMore,
55                        cl::desc("Path of the LLVM sample profile"),
56                        cl::cat(ProfGenCategory));
57 
58 static cl::opt<std::string>
59     BinaryPath("binary", cl::value_desc("binary"), cl::Required,
60                cl::desc("Path of profiled executable binary."),
61                cl::cat(ProfGenCategory));
62 
63 static cl::opt<uint32_t>
64     ProcessId("pid", cl::value_desc("process Id"), cl::ZeroOrMore, cl::init(0),
65               cl::desc("Process Id for the profiled executable binary."),
66               cl::cat(ProfGenCategory));
67 
68 static cl::opt<std::string> DebugBinPath(
69     "debug-binary", cl::value_desc("debug-binary"), cl::ZeroOrMore,
70     cl::desc("Path of debug info binary, llvm-profgen will load the DWARF info "
71              "from it instead of the executable binary."),
72     cl::cat(ProfGenCategory));
73 
74 extern cl::opt<bool> ShowDisassemblyOnly;
75 extern cl::opt<bool> ShowSourceLocations;
76 extern cl::opt<bool> SkipSymbolization;
77 
78 using namespace llvm;
79 using namespace sampleprof;
80 
81 // Validate the command line input.
82 static void validateCommandLine() {
83   // Allow the missing perfscript if we only use to show binary disassembly.
84   if (!ShowDisassemblyOnly) {
85     // Validate input profile is provided only once
86     uint16_t HasPerfData = PerfDataFilename.getNumOccurrences();
87     uint16_t HasPerfScript = PerfScriptFilename.getNumOccurrences();
88     uint16_t HasUnsymbolizedProfile =
89         UnsymbolizedProfFilename.getNumOccurrences();
90     uint16_t HasSampleProfile = SampleProfFilename.getNumOccurrences();
91     uint16_t S =
92         HasPerfData + HasPerfScript + HasUnsymbolizedProfile + HasSampleProfile;
93     if (S != 1) {
94       std::string Msg =
95           S > 1
96               ? "`--perfscript`, `--perfdata` and `--unsymbolized-profile` "
97                 "cannot be used together."
98               : "Perf input file is missing, please use one of `--perfscript`, "
99                 "`--perfdata` and `--unsymbolized-profile` for the input.";
100       exitWithError(Msg);
101     }
102 
103     auto CheckFileExists = [](bool H, StringRef File) {
104       if (H && !llvm::sys::fs::exists(File)) {
105         std::string Msg = "Input perf file(" + File.str() + ") doesn't exist.";
106         exitWithError(Msg);
107       }
108     };
109 
110     CheckFileExists(HasPerfData, PerfDataFilename);
111     CheckFileExists(HasPerfScript, PerfScriptFilename);
112     CheckFileExists(HasUnsymbolizedProfile, UnsymbolizedProfFilename);
113     CheckFileExists(HasSampleProfile, SampleProfFilename);
114   }
115 
116   if (!llvm::sys::fs::exists(BinaryPath)) {
117     std::string Msg = "Input binary(" + BinaryPath + ") doesn't exist.";
118     exitWithError(Msg);
119   }
120 
121   if (CSProfileGenerator::MaxCompressionSize < -1) {
122     exitWithError("Value of --compress-recursion should >= -1");
123   }
124   if (ShowSourceLocations && !ShowDisassemblyOnly) {
125     exitWithError("--show-source-locations should work together with "
126                   "--show-disassembly-only!");
127   }
128 }
129 
130 static PerfInputFile getPerfInputFile() {
131   PerfInputFile File;
132   if (PerfDataFilename.getNumOccurrences()) {
133     File.InputFile = PerfDataFilename;
134     File.Format = PerfFormat::PerfData;
135   } else if (PerfScriptFilename.getNumOccurrences()) {
136     File.InputFile = PerfScriptFilename;
137     File.Format = PerfFormat::PerfScript;
138   } else if (UnsymbolizedProfFilename.getNumOccurrences()) {
139     File.InputFile = UnsymbolizedProfFilename;
140     File.Format = PerfFormat::UnsymbolizedProfile;
141   }
142   return File;
143 }
144 
145 int main(int argc, const char *argv[]) {
146   InitLLVM X(argc, argv);
147 
148   // Initialize targets and assembly printers/parsers.
149   InitializeAllTargetInfos();
150   InitializeAllTargetMCs();
151   InitializeAllDisassemblers();
152 
153   cl::HideUnrelatedOptions({&ProfGenCategory, &getColorCategory()});
154   cl::ParseCommandLineOptions(argc, argv, "llvm SPGO profile generator\n");
155   validateCommandLine();
156 
157   // Load symbols and disassemble the code of a given binary.
158   std::unique_ptr<ProfiledBinary> Binary =
159       std::make_unique<ProfiledBinary>(BinaryPath, DebugBinPath);
160   if (ShowDisassemblyOnly)
161     return EXIT_SUCCESS;
162 
163   if (SampleProfFilename.getNumOccurrences()) {
164     LLVMContext Context;
165     auto ReaderOrErr = SampleProfileReader::create(SampleProfFilename, Context);
166     std::unique_ptr<sampleprof::SampleProfileReader> Reader =
167         std::move(ReaderOrErr.get());
168     Reader->read();
169     std::unique_ptr<ProfileGeneratorBase> Generator =
170         ProfileGeneratorBase::create(Binary.get(),
171                                      std::move(Reader->getProfiles()),
172                                      Reader->profileIsCS());
173     Generator->generateProfile();
174     Generator->write();
175   } else {
176     Optional<uint32_t> PIDFilter;
177     if (ProcessId.getNumOccurrences())
178       PIDFilter = ProcessId;
179     PerfInputFile PerfFile = getPerfInputFile();
180     std::unique_ptr<PerfReaderBase> Reader =
181         PerfReaderBase::create(Binary.get(), PerfFile, PIDFilter);
182     // Parse perf events and samples
183     Reader->parsePerfTraces();
184 
185     if (SkipSymbolization)
186       return EXIT_SUCCESS;
187 
188     std::unique_ptr<ProfileGeneratorBase> Generator =
189         ProfileGeneratorBase::create(Binary.get(), &Reader->getSampleCounters(),
190                                      Reader->profileIsCS());
191     Generator->generateProfile();
192     Generator->write();
193   }
194 
195   return EXIT_SUCCESS;
196 }
197