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/IRReader/IRReader.h"
20 #include "llvm/Linker/Linker.h"
21 #include "llvm/Pass.h"
22 #include "llvm/Support/CommandLine.h"
23 #include "llvm/Support/FileUtilities.h"
24 #include "llvm/Support/Host.h"
25 #include "llvm/Support/SourceMgr.h"
26 #include "llvm/Support/raw_ostream.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(nullptr), Interpreter(nullptr), SafeInterpreter(nullptr),
74 gcc(nullptr), run_find_bugs(find_bugs), Timeout(timeout),
75 MemoryLimit(memlimit), UseValgrind(use_valgrind) {}
76
~BugDriver()77 BugDriver::~BugDriver() {
78 delete Program;
79 if (Interpreter != SafeInterpreter)
80 delete Interpreter;
81 delete SafeInterpreter;
82 delete gcc;
83 }
84
85
86 /// ParseInputFile - Given a bitcode or assembly input filename, parse and
87 /// return it, or return null if not possible.
88 ///
ParseInputFile(const std::string & Filename,LLVMContext & Ctxt)89 Module *llvm::ParseInputFile(const std::string &Filename,
90 LLVMContext& Ctxt) {
91 SMDiagnostic Err;
92 Module *Result = ParseIRFile(Filename, Err, Ctxt);
93 if (!Result)
94 Err.print("bugpoint", errs());
95
96 // If we don't have an override triple, use the first one to configure
97 // bugpoint, or use the host triple if none provided.
98 if (Result) {
99 if (TargetTriple.getTriple().empty()) {
100 Triple TheTriple(Result->getTargetTriple());
101
102 if (TheTriple.getTriple().empty())
103 TheTriple.setTriple(sys::getDefaultTargetTriple());
104
105 TargetTriple.setTriple(TheTriple.getTriple());
106 }
107
108 Result->setTargetTriple(TargetTriple.getTriple()); // override the triple
109 }
110 return Result;
111 }
112
113 // This method takes the specified list of LLVM input files, attempts to load
114 // them, either as assembly or bitcode, then link them together. It returns
115 // true on failure (if, for example, an input bitcode file could not be
116 // parsed), and false on success.
117 //
addSources(const std::vector<std::string> & Filenames)118 bool BugDriver::addSources(const std::vector<std::string> &Filenames) {
119 assert(!Program && "Cannot call addSources multiple times!");
120 assert(!Filenames.empty() && "Must specify at least on input filename!");
121
122 // Load the first input file.
123 Program = ParseInputFile(Filenames[0], Context);
124 if (!Program) return true;
125
126 outs() << "Read input file : '" << Filenames[0] << "'\n";
127
128 for (unsigned i = 1, e = Filenames.size(); i != e; ++i) {
129 std::unique_ptr<Module> M(ParseInputFile(Filenames[i], Context));
130 if (!M.get()) return true;
131
132 outs() << "Linking in input file: '" << Filenames[i] << "'\n";
133 std::string ErrorMessage;
134 if (Linker::LinkModules(Program, M.get(), Linker::DestroySource,
135 &ErrorMessage)) {
136 errs() << ToolName << ": error linking in '" << Filenames[i] << "': "
137 << ErrorMessage << '\n';
138 return true;
139 }
140 }
141
142 outs() << "*** All input ok\n";
143
144 // All input files read successfully!
145 return false;
146 }
147
148
149
150 /// run - The top level method that is invoked after all of the instance
151 /// variables are set up from command line arguments.
152 ///
run(std::string & ErrMsg)153 bool BugDriver::run(std::string &ErrMsg) {
154 if (run_find_bugs) {
155 // Rearrange the passes and apply them to the program. Repeat this process
156 // until the user kills the program or we find a bug.
157 return runManyPasses(PassesToRun, ErrMsg);
158 }
159
160 // If we're not running as a child, the first thing that we must do is
161 // determine what the problem is. Does the optimization series crash the
162 // compiler, or does it produce illegal code? We make the top-level
163 // decision by trying to run all of the passes on the input program,
164 // which should generate a bitcode file. If it does generate a bitcode
165 // file, then we know the compiler didn't crash, so try to diagnose a
166 // miscompilation.
167 if (!PassesToRun.empty()) {
168 outs() << "Running selected passes on program to test for crash: ";
169 if (runPasses(Program, PassesToRun))
170 return debugOptimizerCrash();
171 }
172
173 // Set up the execution environment, selecting a method to run LLVM bitcode.
174 if (initializeExecutionEnvironment()) return true;
175
176 // Test to see if we have a code generator crash.
177 outs() << "Running the code generator to test for a crash: ";
178 std::string Error;
179 compileProgram(Program, &Error);
180 if (!Error.empty()) {
181 outs() << Error;
182 return debugCodeGeneratorCrash(ErrMsg);
183 }
184 outs() << '\n';
185
186 // Run the raw input to see where we are coming from. If a reference output
187 // was specified, make sure that the raw output matches it. If not, it's a
188 // problem in the front-end or the code generator.
189 //
190 bool CreatedOutput = false;
191 if (ReferenceOutputFile.empty()) {
192 outs() << "Generating reference output from raw program: ";
193 if (!createReferenceFile(Program)) {
194 return debugCodeGeneratorCrash(ErrMsg);
195 }
196 CreatedOutput = true;
197 }
198
199 // Make sure the reference output file gets deleted on exit from this
200 // function, if appropriate.
201 std::string ROF(ReferenceOutputFile);
202 FileRemover RemoverInstance(ROF, CreatedOutput && !SaveTemps);
203
204 // Diff the output of the raw program against the reference output. If it
205 // matches, then we assume there is a miscompilation bug and try to
206 // diagnose it.
207 outs() << "*** Checking the code generator...\n";
208 bool Diff = diffProgram(Program, "", "", false, &Error);
209 if (!Error.empty()) {
210 errs() << Error;
211 return debugCodeGeneratorCrash(ErrMsg);
212 }
213 if (!Diff) {
214 outs() << "\n*** Output matches: Debugging miscompilation!\n";
215 debugMiscompilation(&Error);
216 if (!Error.empty()) {
217 errs() << Error;
218 return debugCodeGeneratorCrash(ErrMsg);
219 }
220 return false;
221 }
222
223 outs() << "\n*** Input program does not match reference diff!\n";
224 outs() << "Debugging code generator problem!\n";
225 bool Failure = debugCodeGenerator(&Error);
226 if (!Error.empty()) {
227 errs() << Error;
228 return debugCodeGeneratorCrash(ErrMsg);
229 }
230 return Failure;
231 }
232
PrintFunctionList(const std::vector<Function * > & Funcs)233 void llvm::PrintFunctionList(const std::vector<Function*> &Funcs) {
234 unsigned NumPrint = Funcs.size();
235 if (NumPrint > 10) NumPrint = 10;
236 for (unsigned i = 0; i != NumPrint; ++i)
237 outs() << " " << Funcs[i]->getName();
238 if (NumPrint < Funcs.size())
239 outs() << "... <" << Funcs.size() << " total>";
240 outs().flush();
241 }
242
PrintGlobalVariableList(const std::vector<GlobalVariable * > & GVs)243 void llvm::PrintGlobalVariableList(const std::vector<GlobalVariable*> &GVs) {
244 unsigned NumPrint = GVs.size();
245 if (NumPrint > 10) NumPrint = 10;
246 for (unsigned i = 0; i != NumPrint; ++i)
247 outs() << " " << GVs[i]->getName();
248 if (NumPrint < GVs.size())
249 outs() << "... <" << GVs.size() << " total>";
250 outs().flush();
251 }
252