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/MemoryBuffer.h"
  25 #include "llvm/Support/SourceMgr.h"
  26 #include "llvm/Support/raw_ostream.h"
  27 #include "llvm/System/Host.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.
  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 ///
  60 std::string llvm::getPassesString(const std::vector<const PassInfo*> &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]->getPassArgument();
  66   }
  67   return Result;
  68 }
  69
  70 BugDriver::BugDriver(const char *toolname, bool as_child, bool find_bugs,
  71                      unsigned timeout, unsigned memlimit,
  72                      LLVMContext& ctxt)
  73   : Context(ctxt), ToolName(toolname), ReferenceOutputFile(OutputFile),
  74     Program(0), Interpreter(0), SafeInterpreter(0), gcc(0),
  75     run_as_child(as_child), run_find_bugs(find_bugs), Timeout(timeout),
  76     MemoryLimit(memlimit)  {}
  77
  78
  79 /// ParseInputFile - Given a bitcode or assembly input filename, parse and
  80 /// return it, or return null if not possible.
  81 ///
  82 Module *llvm::ParseInputFile(const std::string &Filename,
  83                              LLVMContext& Ctxt) {
  84   SMDiagnostic Err;
  85   Module *Result = ParseIRFile(Filename, Err, Ctxt);
  86   if (!Result)
  87     Err.Print("bugpoint", errs());
  88
  89   // If we don't have an override triple, use the first one to configure
  90   // bugpoint, or use the host triple if none provided.
  91   if (Result) {
  92     if (TargetTriple.getTriple().empty()) {
  93       Triple TheTriple(Result->getTargetTriple());
  94
  95       if (TheTriple.getTriple().empty())
  96         TheTriple.setTriple(sys::getHostTriple());
  97
  98       TargetTriple.setTriple(TheTriple.getTriple());
  99     }
 100
 101     Result->setTargetTriple(TargetTriple.getTriple());  // override the triple
 102   }
 103   return Result;
 104 }
 105
 106 // This method takes the specified list of LLVM input files, attempts to load
 107 // them, either as assembly or bitcode, then link them together. It returns
 108 // true on failure (if, for example, an input bitcode file could not be
 109 // parsed), and false on success.
 110 //
 111 bool BugDriver::addSources(const std::vector<std::string> &Filenames) {
 112   assert(Program == 0 && "Cannot call addSources multiple times!");
 113   assert(!Filenames.empty() && "Must specify at least on input filename!");
 114
 115   try {
 116     // Load the first input file.
 117     Program = ParseInputFile(Filenames[0], Context);
 118     if (Program == 0) return true;
 119
 120     if (!run_as_child)
 121       outs() << "Read input file      : '" << Filenames[0] << "'\n";
 122
 123     for (unsigned i = 1, e = Filenames.size(); i != e; ++i) {
 124       std::auto_ptr<Module> M(ParseInputFile(Filenames[i], Context));
 125       if (M.get() == 0) return true;
 126
 127       if (!run_as_child)
 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   } catch (const std::string &Error) {
 137     errs() << ToolName << ": error reading input '" << Error << "'\n";
 138     return true;
 139   }
 140
 141   if (!run_as_child)
 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 ///
 153 bool BugDriver::run() {
 154   // The first thing to do is determine if we're running as a child. If we are,
 155   // then what to do is very narrow. This form of invocation is only called
 156   // from the runPasses method to actually run those passes in a child process.
 157   if (run_as_child) {
 158     // Execute the passes
 159     return runPassesAsChild(PassesToRun);
 160   }
 161
 162   if (run_find_bugs) {
 163     // Rearrange the passes and apply them to the program. Repeat this process
 164     // until the user kills the program or we find a bug.
 165     return runManyPasses(PassesToRun);
 166   }
 167
 168   // If we're not running as a child, the first thing that we must do is
 169   // determine what the problem is. Does the optimization series crash the
 170   // compiler, or does it produce illegal code?  We make the top-level
 171   // decision by trying to run all of the passes on the the input program,
 172   // which should generate a bitcode file.  If it does generate a bitcode
 173   // file, then we know the compiler didn't crash, so try to diagnose a
 174   // miscompilation.
 175   if (!PassesToRun.empty()) {
 176     outs() << "Running selected passes on program to test for crash: ";
 177     if (runPasses(PassesToRun))
 178       return debugOptimizerCrash();
 179   }
 180
 181   // Set up the execution environment, selecting a method to run LLVM bitcode.
 182   if (initializeExecutionEnvironment()) return true;
 183
 184   // Test to see if we have a code generator crash.
 185   outs() << "Running the code generator to test for a crash: ";
 186   try {
 187     compileProgram(Program);
 188     outs() << '\n';
 189   } catch (ToolExecutionError &TEE) {
 190     outs() << TEE.what();
 191     return debugCodeGeneratorCrash();
 192   }
 193
 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(!createReferenceFile(Program)){
 203       return debugCodeGeneratorCrash();
 204     }
 205     CreatedOutput = true;
 206   }
 207
 208   // Make sure the reference output file gets deleted on exit from this
 209   // function, if appropriate.
 210   sys::Path ROF(ReferenceOutputFile);
 211   FileRemover RemoverInstance(ROF, CreatedOutput && !SaveTemps);
 212
 213   // Diff the output of the raw program against the reference output.  If it
 214   // matches, then we assume there is a miscompilation bug and try to
 215   // diagnose it.
 216   outs() << "*** Checking the code generator...\n";
 217   try {
 218     if (!diffProgram()) {
 219       outs() << "\n*** Output matches: Debugging miscompilation!\n";
 220       return debugMiscompilation();
 221     }
 222   } catch (ToolExecutionError &TEE) {
 223     errs() << TEE.what();
 224     return debugCodeGeneratorCrash();
 225   }
 226
 227   outs() << "\n*** Input program does not match reference diff!\n";
 228   outs() << "Debugging code generator problem!\n";
 229   try {
 230     return debugCodeGenerator();
 231   } catch (ToolExecutionError &TEE) {
 232     errs() << TEE.what();
 233     return debugCodeGeneratorCrash();
 234   }
 235 }
 236
 237 void llvm::PrintFunctionList(const std::vector<Function*> &Funcs) {
 238   unsigned NumPrint = Funcs.size();
 239   if (NumPrint > 10) NumPrint = 10;
 240   for (unsigned i = 0; i != NumPrint; ++i)
 241     outs() << " " << Funcs[i]->getName();
 242   if (NumPrint < Funcs.size())
 243     outs() << "... <" << Funcs.size() << " total>";
 244   outs().flush();
 245 }
 246
 247 void llvm::PrintGlobalVariableList(const std::vector<GlobalVariable*> &GVs) {
 248   unsigned NumPrint = GVs.size();
 249   if (NumPrint > 10) NumPrint = 10;
 250   for (unsigned i = 0; i != NumPrint; ++i)
 251     outs() << " " << GVs[i]->getName();
 252   if (NumPrint < GVs.size())
 253     outs() << "... <" << GVs.size() << " total>";
 254   outs().flush();
 255 }