1 //===- llvm-reduce.cpp - The LLVM Delta Reduction utility -----------------===//
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 program tries to reduce an IR test case for a given interesting-ness
10 // test. It runs multiple delta debugging passes in order to minimize the input
11 // file. It's worth noting that this is a part of the bugpoint redesign
12 // proposal, and thus a *temporary* tool that will eventually be integrated
13 // into the bugpoint tool itself.
14 //
15 //===----------------------------------------------------------------------===//
16
17 #include "DeltaManager.h"
18 #include "ReducerWorkItem.h"
19 #include "TestRunner.h"
20 #include "llvm/Analysis/ProfileSummaryInfo.h"
21 #include "llvm/Analysis/ModuleSummaryAnalysis.h"
22 #include "llvm/ADT/SmallString.h"
23 #include "llvm/Bitcode/BitcodeReader.h"
24 #include "llvm/Bitcode/BitcodeWriter.h"
25 #include "llvm/CodeGen/CommandFlags.h"
26 #include "llvm/CodeGen/MachineFunction.h"
27 #include "llvm/CodeGen/MachineModuleInfo.h"
28 #include "llvm/IR/LegacyPassManager.h"
29 #include "llvm/IR/LLVMContext.h"
30 #include "llvm/IR/Verifier.h"
31 #include "llvm/IRReader/IRReader.h"
32 #include "llvm/MC/TargetRegistry.h"
33 #include "llvm/Support/CommandLine.h"
34 #include "llvm/Support/Host.h"
35 #include "llvm/Support/InitLLVM.h"
36 #include "llvm/Support/SourceMgr.h"
37 #include "llvm/Support/TargetSelect.h"
38 #include "llvm/Support/WithColor.h"
39 #include "llvm/Support/raw_ostream.h"
40 #include "llvm/Transforms/IPO.h"
41 #include <system_error>
42 #include <vector>
43
44 using namespace llvm;
45
46 cl::OptionCategory LLVMReduceOptions("llvm-reduce options");
47
48 static cl::opt<bool> Help("h", cl::desc("Alias for -help"), cl::Hidden,
49 cl::cat(LLVMReduceOptions));
50 static cl::opt<bool> Version("v", cl::desc("Alias for -version"), cl::Hidden,
51 cl::cat(LLVMReduceOptions));
52
53 static cl::opt<bool>
54 PrintDeltaPasses("print-delta-passes",
55 cl::desc("Print list of delta passes, passable to "
56 "--delta-passes as a comma separated list"),
57 cl::cat(LLVMReduceOptions));
58
59 static cl::opt<std::string> InputFilename(cl::Positional, cl::Required,
60 cl::desc("<input llvm ll/bc file>"),
61 cl::cat(LLVMReduceOptions));
62
63 static cl::opt<std::string>
64 TestFilename("test", cl::Required,
65 cl::desc("Name of the interesting-ness test to be run"),
66 cl::cat(LLVMReduceOptions));
67
68 static cl::list<std::string>
69 TestArguments("test-arg",
70 cl::desc("Arguments passed onto the interesting-ness test"),
71 cl::cat(LLVMReduceOptions));
72
73 static cl::opt<std::string> OutputFilename(
74 "output", cl::desc("Specify the output file. default: reduced.ll|mir"));
75 static cl::alias OutputFileAlias("o", cl::desc("Alias for -output"),
76 cl::aliasopt(OutputFilename),
77 cl::cat(LLVMReduceOptions));
78
79 static cl::opt<bool>
80 ReplaceInput("in-place",
81 cl::desc("WARNING: This option will replace your input file "
82 "with the reduced version!"),
83 cl::cat(LLVMReduceOptions));
84
85 enum class InputLanguages { None, IR, MIR };
86
87 static cl::opt<InputLanguages>
88 InputLanguage("x", cl::ValueOptional,
89 cl::desc("Input language ('ir' or 'mir')"),
90 cl::init(InputLanguages::None),
91 cl::values(clEnumValN(InputLanguages::IR, "ir", ""),
92 clEnumValN(InputLanguages::MIR, "mir", "")),
93 cl::cat(LLVMReduceOptions));
94
95 static cl::opt<int>
96 MaxPassIterations("max-pass-iterations",
97 cl::desc("Maximum number of times to run the full set "
98 "of delta passes (default=5)"),
99 cl::init(5), cl::cat(LLVMReduceOptions));
100
101 static codegen::RegisterCodeGenFlags CGF;
102
writeOutput(ReducerWorkItem & M,StringRef Message)103 void writeOutput(ReducerWorkItem &M, StringRef Message) {
104 if (ReplaceInput) // In-place
105 OutputFilename = InputFilename.c_str();
106 else if (OutputFilename.empty() || OutputFilename == "-")
107 OutputFilename = M.isMIR() ? "reduced.mir" : "reduced.ll";
108 std::error_code EC;
109 raw_fd_ostream Out(OutputFilename, EC);
110 if (EC) {
111 errs() << "Error opening output file: " << EC.message() << "!\n";
112 exit(1);
113 }
114 M.print(Out, /*AnnotationWriter=*/nullptr);
115 errs() << Message << OutputFilename << "\n";
116 }
117
writeBitcode(ReducerWorkItem & M,llvm::raw_ostream & OutStream)118 void writeBitcode(ReducerWorkItem &M, llvm::raw_ostream &OutStream) {
119 if (M.LTOInfo && M.LTOInfo->IsThinLTO && M.LTOInfo->EnableSplitLTOUnit) {
120 legacy::PassManager PM;
121 PM.add(llvm::createWriteThinLTOBitcodePass(OutStream));
122 PM.run(*(M.M));
123 } else {
124 std::unique_ptr<ModuleSummaryIndex> Index;
125 if (M.LTOInfo && M.LTOInfo->HasSummary) {
126 ProfileSummaryInfo PSI(M);
127 Index = std::make_unique<ModuleSummaryIndex>(
128 buildModuleSummaryIndex(M, nullptr, &PSI));
129 }
130 WriteBitcodeToFile(M, OutStream, Index.get());
131 }
132 }
133
readBitcode(ReducerWorkItem & M,MemoryBufferRef Data,LLVMContext & Ctx,const char * ToolName)134 void readBitcode(ReducerWorkItem &M, MemoryBufferRef Data, LLVMContext &Ctx, const char *ToolName) {
135 Expected<BitcodeFileContents> IF = llvm::getBitcodeFileContents(Data);
136 if (!IF) {
137 WithColor::error(errs(), ToolName) << IF.takeError();
138 exit(1);
139 }
140 BitcodeModule BM = IF->Mods[0];
141 Expected<BitcodeLTOInfo> LI = BM.getLTOInfo();
142 Expected<std::unique_ptr<Module>> MOrErr = BM.parseModule(Ctx);
143 if (!LI || !MOrErr) {
144 WithColor::error(errs(), ToolName) << IF.takeError();
145 exit(1);
146 }
147 M.LTOInfo = std::make_unique<BitcodeLTOInfo>(*LI);
148 M.M = std::move(MOrErr.get());
149 }
150
main(int Argc,char ** Argv)151 int main(int Argc, char **Argv) {
152 InitLLVM X(Argc, Argv);
153
154 cl::HideUnrelatedOptions({&LLVMReduceOptions, &getColorCategory()});
155 cl::ParseCommandLineOptions(Argc, Argv, "LLVM automatic testcase reducer.\n");
156
157 bool ReduceModeMIR = false;
158 if (InputLanguage != InputLanguages::None) {
159 if (InputLanguage == InputLanguages::MIR)
160 ReduceModeMIR = true;
161 } else if (StringRef(InputFilename).endswith(".mir")) {
162 ReduceModeMIR = true;
163 }
164
165 if (PrintDeltaPasses) {
166 printDeltaPasses(errs());
167 return 0;
168 }
169
170 LLVMContext Context;
171 std::unique_ptr<TargetMachine> TM;
172
173 std::unique_ptr<ReducerWorkItem> OriginalProgram =
174 parseReducerWorkItem(Argv[0], InputFilename, Context, TM, ReduceModeMIR);
175 if (!OriginalProgram) {
176 return 1;
177 }
178
179 // Initialize test environment
180 TestRunner Tester(TestFilename, TestArguments, std::move(OriginalProgram),
181 std::move(TM), Argv[0]);
182
183 // Try to reduce code
184 runDeltaPasses(Tester, MaxPassIterations);
185
186 // Print reduced file to STDOUT
187 if (OutputFilename == "-")
188 Tester.getProgram().print(outs(), nullptr);
189 else
190 writeOutput(Tester.getProgram(), "\nDone reducing! Reduced testcase: ");
191
192 return 0;
193 }
194