1 //===- BugDriver.h - Top-Level BugPoint class -------------------*- C++ -*-===//
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 #ifndef LLVM_TOOLS_BUGPOINT_BUGDRIVER_H
17 #define LLVM_TOOLS_BUGPOINT_BUGDRIVER_H
18 
19 #include "llvm/IR/ValueMap.h"
20 #include "llvm/Transforms/Utils/ValueMapper.h"
21 #include <memory>
22 #include <string>
23 #include <vector>
24 
25 namespace llvm {
26 
27 class Value;
28 class PassInfo;
29 class Module;
30 class GlobalVariable;
31 class Function;
32 class BasicBlock;
33 class AbstractInterpreter;
34 class Instruction;
35 class LLVMContext;
36 
37 class DebugCrashes;
38 
39 class GCC;
40 
41 extern bool DisableSimplifyCFG;
42 
43 /// BugpointIsInterrupted - Set to true when the user presses ctrl-c.
44 ///
45 extern bool BugpointIsInterrupted;
46 
47 class BugDriver {
48   LLVMContext& Context;
49   const char *ToolName;            // argv[0] of bugpoint
50   std::string ReferenceOutputFile; // Name of `good' output file
51   Module *Program;             // The raw program, linked together
52   std::vector<std::string> PassesToRun;
53   AbstractInterpreter *Interpreter;   // How to run the program
54   AbstractInterpreter *SafeInterpreter;  // To generate reference output, etc.
55   GCC *gcc;
56   bool run_find_bugs;
57   unsigned Timeout;
58   unsigned MemoryLimit;
59   bool UseValgrind;
60 
61   // FIXME: sort out public/private distinctions...
62   friend class ReducePassList;
63   friend class ReduceMisCodegenFunctions;
64 
65 public:
66   BugDriver(const char *toolname, bool find_bugs,
67             unsigned timeout, unsigned memlimit, bool use_valgrind,
68             LLVMContext& ctxt);
69   ~BugDriver();
70 
getToolName()71   const char *getToolName() const { return ToolName; }
72 
getContext()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);
addPass(std::string p)79   void addPass(std::string p) { PassesToRun.push_back(p); }
setPassesToRun(const std::vector<std::string> & PTR)80   void setPassesToRun(const std::vector<std::string> &PTR) {
81     PassesToRun = PTR;
82   }
getPassesToRun()83   const std::vector<std::string> &getPassesToRun() const {
84     return PassesToRun;
85   }
86 
87   /// run - The top level method that is invoked after all of the instance
88   /// variables are set up from command line arguments. The \p as_child argument
89   /// indicates whether the driver is to run in parent mode or child mode.
90   ///
91   bool run(std::string &ErrMsg);
92 
93   /// debugOptimizerCrash - This method is called when some optimizer pass
94   /// crashes on input.  It attempts to prune down the testcase to something
95   /// reasonable, and figure out exactly which pass is crashing.
96   ///
97   bool debugOptimizerCrash(const std::string &ID = "passes");
98 
99   /// debugCodeGeneratorCrash - This method is called when the code generator
100   /// crashes on an input.  It attempts to reduce the input as much as possible
101   /// while still causing the code generator to crash.
102   bool debugCodeGeneratorCrash(std::string &Error);
103 
104   /// debugMiscompilation - This method is used when the passes selected are not
105   /// crashing, but the generated output is semantically different from the
106   /// input.
107   void debugMiscompilation(std::string *Error);
108 
109   /// debugPassMiscompilation - This method is called when the specified pass
110   /// miscompiles Program as input.  It tries to reduce the testcase to
111   /// something that smaller that still miscompiles the program.
112   /// ReferenceOutput contains the filename of the file containing the output we
113   /// are to match.
114   ///
115   bool debugPassMiscompilation(const PassInfo *ThePass,
116                                const std::string &ReferenceOutput);
117 
118   /// compileSharedObject - This method creates a SharedObject from a given
119   /// BitcodeFile for debugging a code generator.
120   ///
121   std::string compileSharedObject(const std::string &BitcodeFile,
122                                   std::string &Error);
123 
124   /// debugCodeGenerator - This method narrows down a module to a function or
125   /// set of functions, using the CBE as a ``safe'' code generator for other
126   /// functions that are not under consideration.
127   bool debugCodeGenerator(std::string *Error);
128 
129   /// isExecutingJIT - Returns true if bugpoint is currently testing the JIT
130   ///
131   bool isExecutingJIT();
132 
133   /// runPasses - Run all of the passes in the "PassesToRun" list, discard the
134   /// output, and return true if any of the passes crashed.
runPasses(Module * M)135   bool runPasses(Module *M) const {
136     return runPasses(M, PassesToRun);
137   }
138 
getProgram()139   Module *getProgram() const { return Program; }
140 
141   /// swapProgramIn - Set the current module to the specified module, returning
142   /// the old one.
swapProgramIn(Module * M)143   Module *swapProgramIn(Module *M) {
144     Module *OldProgram = Program;
145     Program = M;
146     return OldProgram;
147   }
148 
switchToSafeInterpreter()149   AbstractInterpreter *switchToSafeInterpreter() {
150     AbstractInterpreter *Old = Interpreter;
151     Interpreter = (AbstractInterpreter*)SafeInterpreter;
152     return Old;
153   }
154 
switchToInterpreter(AbstractInterpreter * AI)155   void switchToInterpreter(AbstractInterpreter *AI) {
156     Interpreter = AI;
157   }
158 
159   /// setNewProgram - If we reduce or update the program somehow, call this
160   /// method to update bugdriver with it.  This deletes the old module and sets
161   /// the specified one as the current program.
162   void setNewProgram(Module *M);
163 
164   /// compileProgram - Try to compile the specified module, returning false and
165   /// setting Error if an error occurs.  This is used for code generation
166   /// crash testing.
167   ///
168   void compileProgram(Module *M, std::string *Error) const;
169 
170   /// executeProgram - This method runs "Program", capturing the output of the
171   /// program to a file.  A recommended filename may be optionally specified.
172   ///
173   std::string executeProgram(const Module *Program,
174                              std::string OutputFilename,
175                              std::string Bitcode,
176                              const std::string &SharedObjects,
177                              AbstractInterpreter *AI,
178                              std::string *Error) const;
179 
180   /// executeProgramSafely - Used to create reference output with the "safe"
181   /// backend, if reference output is not provided.  If there is a problem with
182   /// the code generator (e.g., llc crashes), this will return false and set
183   /// Error.
184   ///
185   std::string executeProgramSafely(const Module *Program,
186                                    std::string OutputFile,
187                                    std::string *Error) const;
188 
189   /// createReferenceFile - calls compileProgram and then records the output
190   /// into ReferenceOutputFile. Returns true if reference file created, false
191   /// otherwise. Note: initializeExecutionEnvironment should be called BEFORE
192   /// this function.
193   ///
194   bool createReferenceFile(Module *M, const std::string &Filename
195                                             = "bugpoint.reference.out-%%%%%%%");
196 
197   /// diffProgram - This method executes the specified module and diffs the
198   /// output against the file specified by ReferenceOutputFile.  If the output
199   /// is different, 1 is returned.  If there is a problem with the code
200   /// generator (e.g., llc crashes), this will return -1 and set Error.
201   ///
202   bool diffProgram(const Module *Program,
203                    const std::string &BitcodeFile = "",
204                    const std::string &SharedObj = "",
205                    bool RemoveBitcode = false,
206                    std::string *Error = nullptr) const;
207 
208   /// EmitProgressBitcode - This function is used to output M to a file named
209   /// "bugpoint-ID.bc".
210   ///
211   void EmitProgressBitcode(const Module *M, const std::string &ID,
212                            bool NoFlyer = false) const;
213 
214   /// This method clones the current Program and deletes the specified
215   /// instruction from the cloned module.  It then runs a series of cleanup
216   /// passes (ADCE and SimplifyCFG) to eliminate any code which depends on the
217   /// value. The modified module is then returned.
218   ///
219   std::unique_ptr<Module> deleteInstructionFromProgram(const Instruction *I,
220                                                        unsigned Simp);
221 
222   /// This method clones the current Program and performs a series of cleanups
223   /// intended to get rid of extra cruft on the module. If the
224   /// MayModifySemantics argument is true, then the cleanups is allowed to
225   /// modify how the code behaves.
226   ///
227   std::unique_ptr<Module> performFinalCleanups(Module *M,
228                                                bool MayModifySemantics = false);
229 
230   /// Given a module, extract up to one loop from it into a new function. This
231   /// returns null if there are no extractable loops in the program or if the
232   /// loop extractor crashes.
233   std::unique_ptr<Module> extractLoop(Module *M);
234 
235   /// Extract all but the specified basic blocks into their own functions. The
236   /// only detail is that M is actually a module cloned from the one the BBs are
237   /// in, so some mapping needs to be performed. If this operation fails for
238   /// some reason (ie the implementation is buggy), this function should return
239   /// null, otherwise it returns a new Module.
240   std::unique_ptr<Module>
241   extractMappedBlocksFromModule(const std::vector<BasicBlock *> &BBs,
242                                 Module *M);
243 
244   /// Carefully run the specified set of pass on the specified/ module,
245   /// returning the transformed module on success, or a null pointer on failure.
246   /// If AutoDebugCrashes is set to true, then bugpoint will automatically
247   /// attempt to track down a crashing pass if one exists, and this method will
248   /// never return null.
249   std::unique_ptr<Module> runPassesOn(Module *M,
250                                       const std::vector<std::string> &Passes,
251                                       bool AutoDebugCrashes = false,
252                                       unsigned NumExtraArgs = 0,
253                                       const char *const *ExtraArgs = nullptr);
254 
255   /// runPasses - Run the specified passes on Program, outputting a bitcode
256   /// file and writting the filename into OutputFile if successful.  If the
257   /// optimizations fail for some reason (optimizer crashes), return true,
258   /// otherwise return false.  If DeleteOutput is set to true, the bitcode is
259   /// deleted on success, and the filename string is undefined.  This prints to
260   /// outs() a single line message indicating whether compilation was successful
261   /// or failed, unless Quiet is set.  ExtraArgs specifies additional arguments
262   /// to pass to the child bugpoint instance.
263   ///
264   bool runPasses(Module *Program,
265                  const std::vector<std::string> &PassesToRun,
266                  std::string &OutputFilename, bool DeleteOutput = false,
267                  bool Quiet = false, unsigned NumExtraArgs = 0,
268                  const char * const *ExtraArgs = nullptr) const;
269 
270   /// runManyPasses - Take the specified pass list and create different
271   /// combinations of passes to compile the program with. Compile the program with
272   /// each set and mark test to see if it compiled correctly. If the passes
273   /// compiled correctly output nothing and rearrange the passes into a new order.
274   /// If the passes did not compile correctly, output the command required to
275   /// recreate the failure. This returns true if a compiler error is found.
276   ///
277   bool runManyPasses(const std::vector<std::string> &AllPasses,
278                      std::string &ErrMsg);
279 
280   /// writeProgramToFile - This writes the current "Program" to the named
281   /// bitcode file.  If an error occurs, true is returned.
282   ///
283   bool writeProgramToFile(const std::string &Filename, const Module *M) const;
284   bool writeProgramToFile(const std::string &Filename, int FD,
285                           const Module *M) const;
286 
287 private:
288   /// runPasses - Just like the method above, but this just returns true or
289   /// false indicating whether or not the optimizer crashed on the specified
290   /// input (true = crashed).
291   ///
292   bool runPasses(Module *M,
293                  const std::vector<std::string> &PassesToRun,
294                  bool DeleteOutput = true) const {
295     std::string Filename;
296     return runPasses(M, PassesToRun, Filename, DeleteOutput);
297   }
298 
299   /// initializeExecutionEnvironment - This method is used to set up the
300   /// environment for executing LLVM programs.
301   ///
302   bool initializeExecutionEnvironment();
303 };
304 
305 ///  Given a bitcode or assembly input filename, parse and return it, or return
306 ///  null if not possible.
307 ///
308 std::unique_ptr<Module> parseInputFile(StringRef InputFilename,
309                                        LLVMContext &ctxt);
310 
311 /// getPassesString - Turn a list of passes into a string which indicates the
312 /// command line options that must be passed to add the passes.
313 ///
314 std::string getPassesString(const std::vector<std::string> &Passes);
315 
316 /// PrintFunctionList - prints out list of problematic functions
317 ///
318 void PrintFunctionList(const std::vector<Function*> &Funcs);
319 
320 /// PrintGlobalVariableList - prints out list of problematic global variables
321 ///
322 void PrintGlobalVariableList(const std::vector<GlobalVariable*> &GVs);
323 
324 // DeleteFunctionBody - "Remove" the function by deleting all of it's basic
325 // blocks, making it external.
326 //
327 void DeleteFunctionBody(Function *F);
328 
329 /// SplitFunctionsOutOfModule - Given a module and a list of functions in the
330 /// module, split the functions OUT of the specified module, and place them in
331 /// the new module.
332 Module *SplitFunctionsOutOfModule(Module *M, const std::vector<Function*> &F,
333                                   ValueToValueMapTy &VMap);
334 
335 } // End llvm namespace
336 
337 #endif
338