1 //===-- FuzzerCLI.cpp -----------------------------------------------------===//
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 #include "llvm/FuzzMutate/FuzzerCLI.h"
11 #include "llvm/ADT/Triple.h"
12 #include "llvm/Bitcode/BitcodeReader.h"
13 #include "llvm/Bitcode/BitcodeWriter.h"
14 #include "llvm/IR/LLVMContext.h"
15 #include "llvm/Support/CommandLine.h"
16 #include "llvm/Support/Compiler.h"
17 #include "llvm/Support/Error.h"
18 #include "llvm/Support/MemoryBuffer.h"
19 #include "llvm/Support/SourceMgr.h"
20 #include "llvm/Support/raw_ostream.h"
21 #include "llvm/IR/Verifier.h"
22 
23 using namespace llvm;
24 
25 void llvm::parseFuzzerCLOpts(int ArgC, char *ArgV[]) {
26   std::vector<const char *> CLArgs;
27   CLArgs.push_back(ArgV[0]);
28 
29   int I = 1;
30   while (I < ArgC)
31     if (StringRef(ArgV[I++]).equals("-ignore_remaining_args=1"))
32       break;
33   while (I < ArgC)
34     CLArgs.push_back(ArgV[I++]);
35 
36   cl::ParseCommandLineOptions(CLArgs.size(), CLArgs.data());
37 }
38 
39 void llvm::handleExecNameEncodedBEOpts(StringRef ExecName) {
40   std::vector<std::string> Args{ExecName};
41 
42   auto NameAndArgs = ExecName.split("--");
43   if (NameAndArgs.second.empty())
44     return;
45 
46   SmallVector<StringRef, 4> Opts;
47   NameAndArgs.second.split(Opts, '-');
48   for (StringRef Opt : Opts) {
49     if (Opt.equals("gisel")) {
50       Args.push_back("-global-isel");
51       // For now we default GlobalISel to -O0
52       Args.push_back("-O0");
53     } else if (Opt.startswith("O")) {
54       Args.push_back("-" + Opt.str());
55     } else if (Triple(Opt).getArch()) {
56       Args.push_back("-mtriple=" + Opt.str());
57     } else {
58       errs() << ExecName << ": Unknown option: " << Opt << ".\n";
59       exit(1);
60     }
61   }
62   errs() << NameAndArgs.first << ": Injected args:";
63   for (int I = 1, E = Args.size(); I < E; ++I)
64     errs() << " " << Args[I];
65   errs() << "\n";
66 
67   std::vector<const char *> CLArgs;
68   CLArgs.reserve(Args.size());
69   for (std::string &S : Args)
70     CLArgs.push_back(S.c_str());
71 
72   cl::ParseCommandLineOptions(CLArgs.size(), CLArgs.data());
73 }
74 
75 void llvm::handleExecNameEncodedOptimizerOpts(StringRef ExecName) {
76   // TODO: Refactor parts common with the 'handleExecNameEncodedBEOpts'
77   std::vector<std::string> Args{ExecName};
78 
79   auto NameAndArgs = ExecName.split("--");
80   if (NameAndArgs.second.empty())
81     return;
82 
83   SmallVector<StringRef, 4> Opts;
84   NameAndArgs.second.split(Opts, '-');
85   for (StringRef Opt : Opts) {
86     if (Opt.startswith("instcombine")) {
87       Args.push_back("-passes=instcombine");
88     } else if (Opt.startswith("earlycse")) {
89       Args.push_back("-passes=early-cse");
90     } else if (Opt.startswith("simplifycfg")) {
91       Args.push_back("-passes=simplify-cfg");
92     } else if (Opt.startswith("gvn")) {
93       Args.push_back("-passes=gvn");
94     } else if (Opt.startswith("sccp")) {
95       Args.push_back("-passes=sccp");
96     } else if (Triple(Opt).getArch()) {
97       Args.push_back("-mtriple=" + Opt.str());
98     } else {
99       errs() << ExecName << ": Unknown option: " << Opt << ".\n";
100       exit(1);
101     }
102   }
103 
104   errs() << NameAndArgs.first << ": Injected args:";
105   for (int I = 1, E = Args.size(); I < E; ++I)
106     errs() << " " << Args[I];
107   errs() << "\n";
108 
109   std::vector<const char *> CLArgs;
110   CLArgs.reserve(Args.size());
111   for (std::string &S : Args)
112     CLArgs.push_back(S.c_str());
113 
114   cl::ParseCommandLineOptions(CLArgs.size(), CLArgs.data());
115 }
116 
117 int llvm::runFuzzerOnInputs(int ArgC, char *ArgV[], FuzzerTestFun TestOne,
118                             FuzzerInitFun Init) {
119   errs() << "*** This tool was not linked to libFuzzer.\n"
120          << "*** No fuzzing will be performed.\n";
121   if (int RC = Init(&ArgC, &ArgV)) {
122     errs() << "Initialization failed\n";
123     return RC;
124   }
125 
126   for (int I = 1; I < ArgC; ++I) {
127     StringRef Arg(ArgV[I]);
128     if (Arg.startswith("-")) {
129       if (Arg.equals("-ignore_remaining_args=1"))
130         break;
131       continue;
132     }
133 
134     auto BufOrErr = MemoryBuffer::getFile(Arg, /*FileSize-*/ -1,
135                                           /*RequiresNullTerminator=*/false);
136     if (std::error_code EC = BufOrErr.getError()) {
137       errs() << "Error reading file: " << Arg << ": " << EC.message() << "\n";
138       return 1;
139     }
140     std::unique_ptr<MemoryBuffer> Buf = std::move(BufOrErr.get());
141     errs() << "Running: " << Arg << " (" << Buf->getBufferSize() << " bytes)\n";
142     TestOne(reinterpret_cast<const uint8_t *>(Buf->getBufferStart()),
143             Buf->getBufferSize());
144   }
145   return 0;
146 }
147 
148 std::unique_ptr<Module> llvm::parseModule(
149     const uint8_t *Data, size_t Size, LLVMContext &Context) {
150 
151   if (Size <= 1)
152     // We get bogus data given an empty corpus - just create a new module.
153     return llvm::make_unique<Module>("M", Context);
154 
155   auto Buffer = MemoryBuffer::getMemBuffer(
156       StringRef(reinterpret_cast<const char *>(Data), Size), "Fuzzer input",
157       /*RequiresNullTerminator=*/false);
158 
159   SMDiagnostic Err;
160   auto M = parseBitcodeFile(Buffer->getMemBufferRef(), Context);
161   if (Error E = M.takeError()) {
162     errs() << toString(std::move(E)) << "\n";
163     return nullptr;
164   }
165   return std::move(M.get());
166 }
167 
168 size_t llvm::writeModule(const Module &M, uint8_t *Dest, size_t MaxSize) {
169   std::string Buf;
170   {
171     raw_string_ostream OS(Buf);
172     WriteBitcodeToFile(&M, OS);
173   }
174   if (Buf.size() > MaxSize)
175       return 0;
176   memcpy(Dest, Buf.data(), Buf.size());
177   return Buf.size();
178 }
179 
180 std::unique_ptr<Module> llvm::parseAndVerify(const uint8_t *Data, size_t Size,
181                                              LLVMContext &Context) {
182   auto M = parseModule(Data, Size, Context);
183   if (!M || verifyModule(*M, &errs()))
184     return nullptr;
185 
186   return M;
187 }
188