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/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.
  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 ///
  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
  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
  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 ///
  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 //
 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(), &ErrorMessage)) {
 131       errs() << ToolName << ": error linking in '" << Filenames[i] << "': "
 132              << ErrorMessage << '\n';
 133       return true;
 134     }
 135   }
 136
 137   outs() << "*** All input ok\n";
 138
 139   // All input files read successfully!
 140   return false;
 141 }
 142
 143
 144
 145 /// run - The top level method that is invoked after all of the instance
 146 /// variables are set up from command line arguments.
 147 ///
 148 bool BugDriver::run(std::string &ErrMsg) {
 149   if (run_find_bugs) {
 150     // Rearrange the passes and apply them to the program. Repeat this process
 151     // until the user kills the program or we find a bug.
 152     return runManyPasses(PassesToRun, ErrMsg);
 153   }
 154
 155   // If we're not running as a child, the first thing that we must do is
 156   // determine what the problem is. Does the optimization series crash the
 157   // compiler, or does it produce illegal code?  We make the top-level
 158   // decision by trying to run all of the passes on the the input program,
 159   // which should generate a bitcode file.  If it does generate a bitcode
 160   // file, then we know the compiler didn't crash, so try to diagnose a
 161   // miscompilation.
 162   if (!PassesToRun.empty()) {
 163     outs() << "Running selected passes on program to test for crash: ";
 164     if (runPasses(Program, PassesToRun))
 165       return debugOptimizerCrash();
 166   }
 167
 168   // Set up the execution environment, selecting a method to run LLVM bitcode.
 169   if (initializeExecutionEnvironment()) return true;
 170
 171   // Test to see if we have a code generator crash.
 172   outs() << "Running the code generator to test for a crash: ";
 173   std::string Error;
 174   compileProgram(Program, &Error);
 175   if (!Error.empty()) {
 176     outs() << Error;
 177     return debugCodeGeneratorCrash(ErrMsg);
 178   }
 179   outs() << '\n';
 180
 181   // Run the raw input to see where we are coming from.  If a reference output
 182   // was specified, make sure that the raw output matches it.  If not, it's a
 183   // problem in the front-end or the code generator.
 184   //
 185   bool CreatedOutput = false;
 186   if (ReferenceOutputFile.empty()) {
 187     outs() << "Generating reference output from raw program: ";
 188     if (!createReferenceFile(Program)) {
 189       return debugCodeGeneratorCrash(ErrMsg);
 190     }
 191     CreatedOutput = true;
 192   }
 193
 194   // Make sure the reference output file gets deleted on exit from this
 195   // function, if appropriate.
 196   sys::Path ROF(ReferenceOutputFile);
 197   FileRemover RemoverInstance(ROF.str(), CreatedOutput && !SaveTemps);
 198
 199   // Diff the output of the raw program against the reference output.  If it
 200   // matches, then we assume there is a miscompilation bug and try to
 201   // diagnose it.
 202   outs() << "*** Checking the code generator...\n";
 203   bool Diff = diffProgram(Program, "", "", false, &Error);
 204   if (!Error.empty()) {
 205     errs() << Error;
 206     return debugCodeGeneratorCrash(ErrMsg);
 207   }
 208   if (!Diff) {
 209     outs() << "\n*** Output matches: Debugging miscompilation!\n";
 210     debugMiscompilation(&Error);
 211     if (!Error.empty()) {
 212       errs() << Error;
 213       return debugCodeGeneratorCrash(ErrMsg);
 214     }
 215     return false;
 216   }
 217
 218   outs() << "\n*** Input program does not match reference diff!\n";
 219   outs() << "Debugging code generator problem!\n";
 220   bool Failure = debugCodeGenerator(&Error);
 221   if (!Error.empty()) {
 222     errs() << Error;
 223     return debugCodeGeneratorCrash(ErrMsg);
 224   }
 225   return Failure;
 226 }
 227
 228 void llvm::PrintFunctionList(const std::vector<Function*> &Funcs) {
 229   unsigned NumPrint = Funcs.size();
 230   if (NumPrint > 10) NumPrint = 10;
 231   for (unsigned i = 0; i != NumPrint; ++i)
 232     outs() << " " << Funcs[i]->getName();
 233   if (NumPrint < Funcs.size())
 234     outs() << "... <" << Funcs.size() << " total>";
 235   outs().flush();
 236 }
 237
 238 void llvm::PrintGlobalVariableList(const std::vector<GlobalVariable*> &GVs) {
 239   unsigned NumPrint = GVs.size();
 240   if (NumPrint > 10) NumPrint = 10;
 241   for (unsigned i = 0; i != NumPrint; ++i)
 242     outs() << " " << GVs[i]->getName();
 243   if (NumPrint < GVs.size())
 244     outs() << "... <" << GVs.size() << " total>";
 245   outs().flush();
 246 }