tools/bugpoint/BugDriver.cpp

   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 DiscardTemp::~DiscardTemp() {
  36   if (SaveTemps) {
  37     if (Error E = File.keep())
  38       errs() << "Failed to keep temp file " << toString(std::move(E)) << '\n';
  39     return;
  40   }
  41   if (Error E = File.discard())
  42     errs() << "Failed to delete temp file " << toString(std::move(E)) << '\n';
  43 }
  44
  45 // Anonymous namespace to define command line options for debugging.
  46 //
  47 namespace {
  48 // Output - The user can specify a file containing the expected output of the
  49 // program.  If this filename is set, it is used as the reference diff source,
  50 // otherwise the raw input run through an interpreter is used as the reference
  51 // source.
  52 //
  53 cl::opt<std::string> OutputFile("output",
  54                                 cl::desc("Specify a reference program output "
  55                                          "(for miscompilation detection)"));
  56 }
  57
  58 /// If we reduce or update the program somehow, call this method to update
  59 /// bugdriver with it.  This deletes the old module and sets the specified one
  60 /// as the current program.
  61 void BugDriver::setNewProgram(std::unique_ptr<Module> M) {
  62   Program = std::move(M);
  63 }
  64
  65 /// getPassesString - Turn a list of passes into a string which indicates the
  66 /// command line options that must be passed to add the passes.
  67 ///
  68 std::string llvm::getPassesString(const std::vector<std::string> &Passes) {
  69   std::string Result;
  70   for (unsigned i = 0, e = Passes.size(); i != e; ++i) {
  71     if (i)
  72       Result += " ";
  73     Result += "-";
  74     Result += Passes[i];
  75   }
  76   return Result;
  77 }
  78
  79 BugDriver::BugDriver(const char *toolname, bool find_bugs, unsigned timeout,
  80                      unsigned memlimit, bool use_valgrind, LLVMContext &ctxt)
  81     : Context(ctxt), ToolName(toolname), ReferenceOutputFile(OutputFile),
  82       Program(nullptr), Interpreter(nullptr), SafeInterpreter(nullptr),
  83       cc(nullptr), run_find_bugs(find_bugs), Timeout(timeout),
  84       MemoryLimit(memlimit), UseValgrind(use_valgrind) {}
  85
  86 BugDriver::~BugDriver() {
  87   if (Interpreter != SafeInterpreter)
  88     delete Interpreter;
  89   delete SafeInterpreter;
  90   delete cc;
  91 }
  92
  93 std::unique_ptr<Module> llvm::parseInputFile(StringRef Filename,
  94                                              LLVMContext &Ctxt) {
  95   SMDiagnostic Err;
  96   std::unique_ptr<Module> Result = parseIRFile(Filename, Err, Ctxt);
  97   if (!Result) {
  98     Err.print("bugpoint", errs());
  99     return Result;
 100   }
 101
 102   if (verifyModule(*Result, &errs())) {
 103     errs() << "bugpoint: " << Filename << ": error: input module is broken!\n";
 104     return std::unique_ptr<Module>();
 105   }
 106
 107   // If we don't have an override triple, use the first one to configure
 108   // bugpoint, or use the host triple if none provided.
 109   if (TargetTriple.getTriple().empty()) {
 110     Triple TheTriple(Result->getTargetTriple());
 111
 112     if (TheTriple.getTriple().empty())
 113       TheTriple.setTriple(sys::getDefaultTargetTriple());
 114
 115     TargetTriple.setTriple(TheTriple.getTriple());
 116   }
 117
 118   Result->setTargetTriple(TargetTriple.getTriple()); // override the triple
 119   return Result;
 120 }
 121
 122 std::unique_ptr<Module> BugDriver::swapProgramIn(std::unique_ptr<Module> M) {
 123   std::unique_ptr<Module> OldProgram = std::move(Program);
 124   Program = std::move(M);
 125   return OldProgram;
 126 }
 127
 128 // This method takes the specified list of LLVM input files, attempts to load
 129 // them, either as assembly or bitcode, then link them together. It returns
 130 // true on failure (if, for example, an input bitcode file could not be
 131 // parsed), and false on success.
 132 //
 133 bool BugDriver::addSources(const std::vector<std::string> &Filenames) {
 134   assert(!Program && "Cannot call addSources multiple times!");
 135   assert(!Filenames.empty() && "Must specify at least on input filename!");
 136
 137   // Load the first input file.
 138   Program = parseInputFile(Filenames[0], Context);
 139   if (!Program)
 140     return true;
 141
 142   outs() << "Read input file      : '" << Filenames[0] << "'\n";
 143
 144   for (unsigned i = 1, e = Filenames.size(); i != e; ++i) {
 145     std::unique_ptr<Module> M = parseInputFile(Filenames[i], Context);
 146     if (!M.get())
 147       return true;
 148
 149     outs() << "Linking in input file: '" << Filenames[i] << "'\n";
 150     if (Linker::linkModules(*Program, std::move(M)))
 151       return true;
 152   }
 153
 154   outs() << "*** All input ok\n";
 155
 156   // All input files read successfully!
 157   return false;
 158 }
 159
 160 /// run - The top level method that is invoked after all of the instance
 161 /// variables are set up from command line arguments.
 162 ///
 163 Error BugDriver::run() {
 164   if (run_find_bugs) {
 165     // Rearrange the passes and apply them to the program. Repeat this process
 166     // until the user kills the program or we find a bug.
 167     return runManyPasses(PassesToRun);
 168   }
 169
 170   // If we're not running as a child, the first thing that we must do is
 171   // determine what the problem is. Does the optimization series crash the
 172   // compiler, or does it produce illegal code?  We make the top-level
 173   // decision by trying to run all of the passes on the input program,
 174   // which should generate a bitcode file.  If it does generate a bitcode
 175   // file, then we know the compiler didn't crash, so try to diagnose a
 176   // miscompilation.
 177   if (!PassesToRun.empty()) {
 178     outs() << "Running selected passes on program to test for crash: ";
 179     if (runPasses(*Program, PassesToRun))
 180       return debugOptimizerCrash();
 181   }
 182
 183   // Set up the execution environment, selecting a method to run LLVM bitcode.
 184   if (Error E = initializeExecutionEnvironment())
 185     return E;
 186
 187   // Test to see if we have a code generator crash.
 188   outs() << "Running the code generator to test for a crash: ";
 189   if (Error E = compileProgram(*Program)) {
 190     outs() << toString(std::move(E));
 191     return debugCodeGeneratorCrash();
 192   }
 193   outs() << '\n';
 194
 195   // Run the raw input to see where we are coming from.  If a reference output
 196   // was specified, make sure that the raw output matches it.  If not, it's a
 197   // problem in the front-end or the code generator.
 198   //
 199   bool CreatedOutput = false;
 200   if (ReferenceOutputFile.empty()) {
 201     outs() << "Generating reference output from raw program: ";
 202     if (Error E = createReferenceFile(*Program)) {
 203       errs() << toString(std::move(E));
 204       return debugCodeGeneratorCrash();
 205     }
 206     CreatedOutput = true;
 207   }
 208
 209   // Make sure the reference output file gets deleted on exit from this
 210   // function, if appropriate.
 211   std::string ROF(ReferenceOutputFile);
 212   FileRemover RemoverInstance(ROF, CreatedOutput && !SaveTemps);
 213
 214   // Diff the output of the raw program against the reference output.  If it
 215   // matches, then we assume there is a miscompilation bug and try to
 216   // diagnose it.
 217   outs() << "*** Checking the code generator...\n";
 218   Expected<bool> Diff = diffProgram(*Program, "", "", false);
 219   if (Error E = Diff.takeError()) {
 220     errs() << toString(std::move(E));
 221     return debugCodeGeneratorCrash();
 222   }
 223   if (!*Diff) {
 224     outs() << "\n*** Output matches: Debugging miscompilation!\n";
 225     if (Error E = debugMiscompilation()) {
 226       errs() << toString(std::move(E));
 227       return debugCodeGeneratorCrash();
 228     }
 229     return Error::success();
 230   }
 231
 232   outs() << "\n*** Input program does not match reference diff!\n";
 233   outs() << "Debugging code generator problem!\n";
 234   if (Error E = debugCodeGenerator()) {
 235     errs() << toString(std::move(E));
 236     return debugCodeGeneratorCrash();
 237   }
 238   return Error::success();
 239 }
 240
 241 void llvm::PrintFunctionList(const std::vector<Function *> &Funcs) {
 242   unsigned NumPrint = Funcs.size();
 243   if (NumPrint > 10)
 244     NumPrint = 10;
 245   for (unsigned i = 0; i != NumPrint; ++i)
 246     outs() << " " << Funcs[i]->getName();
 247   if (NumPrint < Funcs.size())
 248     outs() << "... <" << Funcs.size() << " total>";
 249   outs().flush();
 250 }
 251
 252 void llvm::PrintGlobalVariableList(const std::vector<GlobalVariable *> &GVs) {
 253   unsigned NumPrint = GVs.size();
 254   if (NumPrint > 10)
 255     NumPrint = 10;
 256   for (unsigned i = 0; i != NumPrint; ++i)
 257     outs() << " " << GVs[i]->getName();
 258   if (NumPrint < GVs.size())
 259     outs() << "... <" << GVs.size() << " total>";
 260   outs().flush();
 261 }