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