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