1 //===- BugDriver.cpp - Top-Level BugPoint class implementation ------------===//
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 class contains all of the shared state and information that is used by
11 // the BugPoint tool to track down errors in optimizations. This class is the
12 // main driver class that invokes all sub-functionality.
13 //
14 //===----------------------------------------------------------------------===//
15
16 #include "BugDriver.h"
17 #include "ToolRunner.h"
18 #include "llvm/IR/Module.h"
19 #include "llvm/IR/Verifier.h"
20 #include "llvm/IRReader/IRReader.h"
21 #include "llvm/Linker/Linker.h"
22 #include "llvm/Pass.h"
23 #include "llvm/Support/CommandLine.h"
24 #include "llvm/Support/FileUtilities.h"
25 #include "llvm/Support/Host.h"
26 #include "llvm/Support/SourceMgr.h"
27 #include "llvm/Support/raw_ostream.h"
28 #include <memory>
29 using namespace llvm;
30
31 namespace llvm {
32 Triple TargetTriple;
33 }
34
35 // Anonymous namespace to define command line options for debugging.
36 //
37 namespace {
38 // Output - The user can specify a file containing the expected output of the
39 // program. If this filename is set, it is used as the reference diff source,
40 // otherwise the raw input run through an interpreter is used as the reference
41 // source.
42 //
43 cl::opt<std::string>
44 OutputFile("output", cl::desc("Specify a reference program output "
45 "(for miscompilation detection)"));
46 }
47
48 /// setNewProgram - If we reduce or update the program somehow, call this method
49 /// to update bugdriver with it. This deletes the old module and sets the
50 /// specified one as the current program.
setNewProgram(Module * M)51 void BugDriver::setNewProgram(Module *M) {
52 delete Program;
53 Program = M;
54 }
55
56
57 /// getPassesString - Turn a list of passes into a string which indicates the
58 /// command line options that must be passed to add the passes.
59 ///
getPassesString(const std::vector<std::string> & Passes)60 std::string llvm::getPassesString(const std::vector<std::string> &Passes) {
61 std::string Result;
62 for (unsigned i = 0, e = Passes.size(); i != e; ++i) {
63 if (i) Result += " ";
64 Result += "-";
65 Result += Passes[i];
66 }
67 return Result;
68 }
69
BugDriver(const char * toolname,bool find_bugs,unsigned timeout,unsigned memlimit,bool use_valgrind,LLVMContext & ctxt)70 BugDriver::BugDriver(const char *toolname, bool find_bugs,
71 unsigned timeout, unsigned memlimit, bool use_valgrind,
72 LLVMContext& ctxt)
73 : Context(ctxt), ToolName(toolname), ReferenceOutputFile(OutputFile),
74 Program(nullptr), Interpreter(nullptr), SafeInterpreter(nullptr),
75 gcc(nullptr), run_find_bugs(find_bugs), Timeout(timeout),
76 MemoryLimit(memlimit), UseValgrind(use_valgrind) {}
77
~BugDriver()78 BugDriver::~BugDriver() {
79 delete Program;
80 if (Interpreter != SafeInterpreter)
81 delete Interpreter;
82 delete SafeInterpreter;
83 delete gcc;
84 }
85
parseInputFile(StringRef Filename,LLVMContext & Ctxt)86 std::unique_ptr<Module> llvm::parseInputFile(StringRef Filename,
87 LLVMContext &Ctxt) {
88 SMDiagnostic Err;
89 std::unique_ptr<Module> Result = parseIRFile(Filename, Err, Ctxt);
90 if (!Result) {
91 Err.print("bugpoint", errs());
92 return Result;
93 }
94
95 if (verifyModule(*Result, &errs())) {
96 errs() << "bugpoint: " << Filename << ": error: input module is broken!\n";
97 return std::unique_ptr<Module>();
98 }
99
100 // If we don't have an override triple, use the first one to configure
101 // bugpoint, or use the host triple if none provided.
102 if (TargetTriple.getTriple().empty()) {
103 Triple TheTriple(Result->getTargetTriple());
104
105 if (TheTriple.getTriple().empty())
106 TheTriple.setTriple(sys::getDefaultTargetTriple());
107
108 TargetTriple.setTriple(TheTriple.getTriple());
109 }
110
111 Result->setTargetTriple(TargetTriple.getTriple()); // override the triple
112 return Result;
113 }
114
115 // This method takes the specified list of LLVM input files, attempts to load
116 // them, either as assembly or bitcode, then link them together. It returns
117 // true on failure (if, for example, an input bitcode file could not be
118 // parsed), and false on success.
119 //
addSources(const std::vector<std::string> & Filenames)120 bool BugDriver::addSources(const std::vector<std::string> &Filenames) {
121 assert(!Program && "Cannot call addSources multiple times!");
122 assert(!Filenames.empty() && "Must specify at least on input filename!");
123
124 // Load the first input file.
125 Program = parseInputFile(Filenames[0], Context).release();
126 if (!Program) return true;
127
128 outs() << "Read input file : '" << Filenames[0] << "'\n";
129
130 for (unsigned i = 1, e = Filenames.size(); i != e; ++i) {
131 std::unique_ptr<Module> M = parseInputFile(Filenames[i], Context);
132 if (!M.get()) return true;
133
134 outs() << "Linking in input file: '" << Filenames[i] << "'\n";
135 if (Linker::LinkModules(Program, M.get()))
136 return true;
137 }
138
139 outs() << "*** All input ok\n";
140
141 // All input files read successfully!
142 return false;
143 }
144
145
146
147 /// run - The top level method that is invoked after all of the instance
148 /// variables are set up from command line arguments.
149 ///
run(std::string & ErrMsg)150 bool BugDriver::run(std::string &ErrMsg) {
151 if (run_find_bugs) {
152 // Rearrange the passes and apply them to the program. Repeat this process
153 // until the user kills the program or we find a bug.
154 return runManyPasses(PassesToRun, ErrMsg);
155 }
156
157 // If we're not running as a child, the first thing that we must do is
158 // determine what the problem is. Does the optimization series crash the
159 // compiler, or does it produce illegal code? We make the top-level
160 // decision by trying to run all of the passes on the input program,
161 // which should generate a bitcode file. If it does generate a bitcode
162 // file, then we know the compiler didn't crash, so try to diagnose a
163 // miscompilation.
164 if (!PassesToRun.empty()) {
165 outs() << "Running selected passes on program to test for crash: ";
166 if (runPasses(Program, PassesToRun))
167 return debugOptimizerCrash();
168 }
169
170 // Set up the execution environment, selecting a method to run LLVM bitcode.
171 if (initializeExecutionEnvironment()) return true;
172
173 // Test to see if we have a code generator crash.
174 outs() << "Running the code generator to test for a crash: ";
175 std::string Error;
176 compileProgram(Program, &Error);
177 if (!Error.empty()) {
178 outs() << Error;
179 return debugCodeGeneratorCrash(ErrMsg);
180 }
181 outs() << '\n';
182
183 // Run the raw input to see where we are coming from. If a reference output
184 // was specified, make sure that the raw output matches it. If not, it's a
185 // problem in the front-end or the code generator.
186 //
187 bool CreatedOutput = false;
188 if (ReferenceOutputFile.empty()) {
189 outs() << "Generating reference output from raw program: ";
190 if (!createReferenceFile(Program)) {
191 return debugCodeGeneratorCrash(ErrMsg);
192 }
193 CreatedOutput = true;
194 }
195
196 // Make sure the reference output file gets deleted on exit from this
197 // function, if appropriate.
198 std::string ROF(ReferenceOutputFile);
199 FileRemover RemoverInstance(ROF, CreatedOutput && !SaveTemps);
200
201 // Diff the output of the raw program against the reference output. If it
202 // matches, then we assume there is a miscompilation bug and try to
203 // diagnose it.
204 outs() << "*** Checking the code generator...\n";
205 bool Diff = diffProgram(Program, "", "", false, &Error);
206 if (!Error.empty()) {
207 errs() << Error;
208 return debugCodeGeneratorCrash(ErrMsg);
209 }
210 if (!Diff) {
211 outs() << "\n*** Output matches: Debugging miscompilation!\n";
212 debugMiscompilation(&Error);
213 if (!Error.empty()) {
214 errs() << Error;
215 return debugCodeGeneratorCrash(ErrMsg);
216 }
217 return false;
218 }
219
220 outs() << "\n*** Input program does not match reference diff!\n";
221 outs() << "Debugging code generator problem!\n";
222 bool Failure = debugCodeGenerator(&Error);
223 if (!Error.empty()) {
224 errs() << Error;
225 return debugCodeGeneratorCrash(ErrMsg);
226 }
227 return Failure;
228 }
229
PrintFunctionList(const std::vector<Function * > & Funcs)230 void llvm::PrintFunctionList(const std::vector<Function*> &Funcs) {
231 unsigned NumPrint = Funcs.size();
232 if (NumPrint > 10) NumPrint = 10;
233 for (unsigned i = 0; i != NumPrint; ++i)
234 outs() << " " << Funcs[i]->getName();
235 if (NumPrint < Funcs.size())
236 outs() << "... <" << Funcs.size() << " total>";
237 outs().flush();
238 }
239
PrintGlobalVariableList(const std::vector<GlobalVariable * > & GVs)240 void llvm::PrintGlobalVariableList(const std::vector<GlobalVariable*> &GVs) {
241 unsigned NumPrint = GVs.size();
242 if (NumPrint > 10) NumPrint = 10;
243 for (unsigned i = 0; i != NumPrint; ++i)
244 outs() << " " << GVs[i]->getName();
245 if (NumPrint < GVs.size())
246 outs() << "... <" << GVs.size() << " total>";
247 outs().flush();
248 }
249