tools/bugpoint/BugDriver.h

   1 //===- BugDriver.h - Top-Level BugPoint class -------------------*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This class contains all of the shared state and information that is used by
  10 // the BugPoint tool to track down errors in optimizations.  This class is the
  11 // main driver class that invokes all sub-functionality.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #ifndef LLVM_TOOLS_BUGPOINT_BUGDRIVER_H
  16 #define LLVM_TOOLS_BUGPOINT_BUGDRIVER_H
  17
  18 #include "llvm/IR/ValueMap.h"
  19 #include "llvm/Support/Error.h"
  20 #include "llvm/Support/FileSystem.h"
  21 #include "llvm/Transforms/Utils/ValueMapper.h"
  22 #include <memory>
  23 #include <string>
  24 #include <vector>
  25
  26 namespace llvm {
  27
  28 class Value;
  29 class PassInfo;
  30 class Module;
  31 class GlobalVariable;
  32 class Function;
  33 class BasicBlock;
  34 class AbstractInterpreter;
  35 class Instruction;
  36 class LLVMContext;
  37
  38 class DebugCrashes;
  39
  40 class CC;
  41
  42 extern bool DisableSimplifyCFG;
  43
  44 /// BugpointIsInterrupted - Set to true when the user presses ctrl-c.
  45 ///
  46 extern bool BugpointIsInterrupted;
  47
  48 class BugDriver {
  49   LLVMContext &Context;
  50   const char *ToolName;            // argv[0] of bugpoint
  51   std::string ReferenceOutputFile; // Name of `good' output file
  52   std::unique_ptr<Module> Program; // The raw program, linked together
  53   std::vector<std::string> PassesToRun;
  54   AbstractInterpreter *Interpreter;     // How to run the program
  55   AbstractInterpreter *SafeInterpreter; // To generate reference output, etc.
  56   CC *cc;
  57   bool run_find_bugs;
  58   unsigned Timeout;
  59   unsigned MemoryLimit;
  60   bool UseValgrind;
  61
  62   // FIXME: sort out public/private distinctions...
  63   friend class ReducePassList;
  64   friend class ReduceMisCodegenFunctions;
  65
  66 public:
  67   BugDriver(const char *toolname, bool find_bugs, unsigned timeout,
  68             unsigned memlimit, bool use_valgrind, LLVMContext &ctxt);
  69   ~BugDriver();
  70
  71   const char *getToolName() const { return ToolName; }
  72
  73   LLVMContext &getContext() const { return Context; }
  74
  75   // Set up methods... these methods are used to copy information about the
  76   // command line arguments into instance variables of BugDriver.
  77   //
  78   bool addSources(const std::vector<std::string> &FileNames);
  79   void addPass(std::string p) { PassesToRun.push_back(std::move(p)); }
  80   void setPassesToRun(const std::vector<std::string> &PTR) {
  81     PassesToRun = PTR;
  82   }
  83   const std::vector<std::string> &getPassesToRun() const { return PassesToRun; }
  84
  85   /// run - The top level method that is invoked after all of the instance
  86   /// variables are set up from command line arguments. The \p as_child argument
  87   /// indicates whether the driver is to run in parent mode or child mode.
  88   ///
  89   Error run();
  90
  91   /// debugOptimizerCrash - This method is called when some optimizer pass
  92   /// crashes on input.  It attempts to prune down the testcase to something
  93   /// reasonable, and figure out exactly which pass is crashing.
  94   ///
  95   Error debugOptimizerCrash(const std::string &ID = "passes");
  96
  97   /// debugCodeGeneratorCrash - This method is called when the code generator
  98   /// crashes on an input.  It attempts to reduce the input as much as possible
  99   /// while still causing the code generator to crash.
 100   Error debugCodeGeneratorCrash();
 101
 102   /// debugMiscompilation - This method is used when the passes selected are not
 103   /// crashing, but the generated output is semantically different from the
 104   /// input.
 105   Error debugMiscompilation();
 106
 107   /// debugPassMiscompilation - This method is called when the specified pass
 108   /// miscompiles Program as input.  It tries to reduce the testcase to
 109   /// something that smaller that still miscompiles the program.
 110   /// ReferenceOutput contains the filename of the file containing the output we
 111   /// are to match.
 112   ///
 113   bool debugPassMiscompilation(const PassInfo *ThePass,
 114                                const std::string &ReferenceOutput);
 115
 116   /// compileSharedObject - This method creates a SharedObject from a given
 117   /// BitcodeFile for debugging a code generator.
 118   ///
 119   Expected<std::string> compileSharedObject(const std::string &BitcodeFile);
 120
 121   /// debugCodeGenerator - This method narrows down a module to a function or
 122   /// set of functions, using the CBE as a ``safe'' code generator for other
 123   /// functions that are not under consideration.
 124   Error debugCodeGenerator();
 125
 126   /// isExecutingJIT - Returns true if bugpoint is currently testing the JIT
 127   ///
 128   bool isExecutingJIT();
 129
 130   Module &getProgram() const { return *Program; }
 131
 132   /// Set the current module to the specified module, returning the old one.
 133   std::unique_ptr<Module> swapProgramIn(std::unique_ptr<Module> M);
 134
 135   AbstractInterpreter *switchToSafeInterpreter() {
 136     AbstractInterpreter *Old = Interpreter;
 137     Interpreter = (AbstractInterpreter *)SafeInterpreter;
 138     return Old;
 139   }
 140
 141   void switchToInterpreter(AbstractInterpreter *AI) { Interpreter = AI; }
 142
 143   /// If we reduce or update the program somehow, call this method to update
 144   /// bugdriver with it.  This deletes the old module and sets the specified one
 145   /// as the current program.
 146   void setNewProgram(std::unique_ptr<Module> M);
 147
 148   /// Try to compile the specified module. This is used for code generation
 149   /// crash testing.
 150   Error compileProgram(Module &M) const;
 151
 152   /// This method runs "Program", capturing the output of the program to a file.
 153   /// A recommended filename may be optionally specified.
 154   Expected<std::string> executeProgram(const Module &Program,
 155                                        std::string OutputFilename,
 156                                        std::string Bitcode,
 157                                        const std::string &SharedObjects,
 158                                        AbstractInterpreter *AI) const;
 159
 160   /// Used to create reference output with the "safe" backend, if reference
 161   /// output is not provided.  If there is a problem with the code generator
 162   /// (e.g., llc crashes), this will return false and set Error.
 163   Expected<std::string>
 164   executeProgramSafely(const Module &Program,
 165                        const std::string &OutputFile) const;
 166
 167   /// Calls compileProgram and then records the output into ReferenceOutputFile.
 168   /// Returns true if reference file created, false otherwise. Note:
 169   /// initializeExecutionEnvironment should be called BEFORE this function.
 170   Error createReferenceFile(Module &M, const std::string &Filename =
 171                                            "bugpoint.reference.out-%%%%%%%");
 172
 173   /// This method executes the specified module and diffs the output against the
 174   /// file specified by ReferenceOutputFile.  If the output is different, 1 is
 175   /// returned.  If there is a problem with the code generator (e.g., llc
 176   /// crashes), this will return -1 and set Error.
 177   Expected<bool> diffProgram(const Module &Program,
 178                              const std::string &BitcodeFile = "",
 179                              const std::string &SharedObj = "",
 180                              bool RemoveBitcode = false) const;
 181
 182   /// This function is used to output M to a file named "bugpoint-ID.bc".
 183   void EmitProgressBitcode(const Module &M, const std::string &ID,
 184                            bool NoFlyer = false) const;
 185
 186   /// This method clones the current Program and deletes the specified
 187   /// instruction from the cloned module.  It then runs a series of cleanup
 188   /// passes (ADCE and SimplifyCFG) to eliminate any code which depends on the
 189   /// value. The modified module is then returned.
 190   ///
 191   std::unique_ptr<Module> deleteInstructionFromProgram(const Instruction *I,
 192                                                        unsigned Simp);
 193
 194   /// This method clones the current Program and performs a series of cleanups
 195   /// intended to get rid of extra cruft on the module. If the
 196   /// MayModifySemantics argument is true, then the cleanups is allowed to
 197   /// modify how the code behaves.
 198   ///
 199   std::unique_ptr<Module> performFinalCleanups(std::unique_ptr<Module> M,
 200                                                bool MayModifySemantics = false);
 201
 202   /// Given a module, extract up to one loop from it into a new function. This
 203   /// returns null if there are no extractable loops in the program or if the
 204   /// loop extractor crashes.
 205   std::unique_ptr<Module> extractLoop(Module *M);
 206
 207   /// Extract all but the specified basic blocks into their own functions. The
 208   /// only detail is that M is actually a module cloned from the one the BBs are
 209   /// in, so some mapping needs to be performed. If this operation fails for
 210   /// some reason (ie the implementation is buggy), this function should return
 211   /// null, otherwise it returns a new Module.
 212   std::unique_ptr<Module>
 213   extractMappedBlocksFromModule(const std::vector<BasicBlock *> &BBs,
 214                                 Module *M);
 215
 216   /// Carefully run the specified set of pass on the specified/ module,
 217   /// returning the transformed module on success, or a null pointer on failure.
 218   std::unique_ptr<Module> runPassesOn(Module *M,
 219                                       const std::vector<std::string> &Passes,
 220                                       ArrayRef<std::string> ExtraArgs = {});
 221
 222   /// runPasses - Run the specified passes on Program, outputting a bitcode
 223   /// file and writting the filename into OutputFile if successful.  If the
 224   /// optimizations fail for some reason (optimizer crashes), return true,
 225   /// otherwise return false.  If DeleteOutput is set to true, the bitcode is
 226   /// deleted on success, and the filename string is undefined.  This prints to
 227   /// outs() a single line message indicating whether compilation was successful
 228   /// or failed, unless Quiet is set.  ExtraArgs specifies additional arguments
 229   /// to pass to the child bugpoint instance.
 230   ///
 231   bool runPasses(Module &Program, const std::vector<std::string> &PassesToRun,
 232                  std::string &OutputFilename, bool DeleteOutput = false,
 233                  bool Quiet = false,
 234                  ArrayRef<std::string> ExtraArgs = {}) const;
 235
 236   /// runPasses - Just like the method above, but this just returns true or
 237   /// false indicating whether or not the optimizer crashed on the specified
 238   /// input (true = crashed).  Does not produce any output.
 239   ///
 240   bool runPasses(Module &M, const std::vector<std::string> &PassesToRun) const {
 241     std::string Filename;
 242     return runPasses(M, PassesToRun, Filename, true);
 243   }
 244
 245   /// Take the specified pass list and create different combinations of passes
 246   /// to compile the program with. Compile the program with each set and mark
 247   /// test to see if it compiled correctly. If the passes compiled correctly
 248   /// output nothing and rearrange the passes into a new order. If the passes
 249   /// did not compile correctly, output the command required to recreate the
 250   /// failure.
 251   Error runManyPasses(const std::vector<std::string> &AllPasses);
 252
 253   /// This writes the current "Program" to the named bitcode file.  If an error
 254   /// occurs, true is returned.
 255   bool writeProgramToFile(const std::string &Filename, const Module &M) const;
 256   bool writeProgramToFile(const std::string &Filename, int FD,
 257                           const Module &M) const;
 258   bool writeProgramToFile(int FD, const Module &M) const;
 259
 260 private:
 261   /// initializeExecutionEnvironment - This method is used to set up the
 262   /// environment for executing LLVM programs.
 263   ///
 264   Error initializeExecutionEnvironment();
 265 };
 266
 267 struct DiscardTemp {
 268   sys::fs::TempFile &File;
 269   ~DiscardTemp();
 270 };
 271
 272 ///  Given a bitcode or assembly input filename, parse and return it, or return
 273 ///  null if not possible.
 274 ///
 275 std::unique_ptr<Module> parseInputFile(StringRef InputFilename,
 276                                        LLVMContext &ctxt);
 277
 278 /// getPassesString - Turn a list of passes into a string which indicates the
 279 /// command line options that must be passed to add the passes.
 280 ///
 281 std::string getPassesString(const std::vector<std::string> &Passes);
 282
 283 /// PrintFunctionList - prints out list of problematic functions
 284 ///
 285 void PrintFunctionList(const std::vector<Function *> &Funcs);
 286
 287 /// PrintGlobalVariableList - prints out list of problematic global variables
 288 ///
 289 void PrintGlobalVariableList(const std::vector<GlobalVariable *> &GVs);
 290
 291 // DeleteGlobalInitializer - "Remove" the global variable by deleting its
 292 // initializer, making it external.
 293 //
 294 void DeleteGlobalInitializer(GlobalVariable *GV);
 295
 296 // DeleteFunctionBody - "Remove" the function by deleting all of it's basic
 297 // blocks, making it external.
 298 //
 299 void DeleteFunctionBody(Function *F);
 300
 301 /// Given a module and a list of functions in the module, split the functions
 302 /// OUT of the specified module, and place them in the new module.
 303 std::unique_ptr<Module>
 304 SplitFunctionsOutOfModule(Module *M, const std::vector<Function *> &F,
 305                           ValueToValueMapTy &VMap);
 306
 307 } // End llvm namespace
 308
 309 #endif