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/IR/Module.h"
19#include "llvm/IRReader/IRReader.h"
20#include "llvm/Linker/Linker.h"
21#include "llvm/Pass.h"
22#include "llvm/Support/CommandLine.h"
23#include "llvm/Support/FileUtilities.h"
24#include "llvm/Support/Host.h"
25#include "llvm/Support/SourceMgr.h"
26#include "llvm/Support/raw_ostream.h"
27#include <memory>
28using namespace llvm;
29
30namespace llvm {
31  Triple TargetTriple;
32}
33
34// Anonymous namespace to define command line options for debugging.
35//
36namespace {
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.
50void 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///
59std::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
69BugDriver::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(nullptr), Interpreter(nullptr), SafeInterpreter(nullptr),
74    gcc(nullptr), run_find_bugs(find_bugs), Timeout(timeout),
75    MemoryLimit(memlimit), UseValgrind(use_valgrind) {}
76
77BugDriver::~BugDriver() {
78  delete Program;
79  if (Interpreter != SafeInterpreter)
80    delete Interpreter;
81  delete SafeInterpreter;
82  delete gcc;
83}
84
85
86/// ParseInputFile - Given a bitcode or assembly input filename, parse and
87/// return it, or return null if not possible.
88///
89Module *llvm::ParseInputFile(const std::string &Filename,
90                             LLVMContext& Ctxt) {
91  SMDiagnostic Err;
92  Module *Result = ParseIRFile(Filename, Err, Ctxt);
93  if (!Result)
94    Err.print("bugpoint", errs());
95
96  // If we don't have an override triple, use the first one to configure
97  // bugpoint, or use the host triple if none provided.
98  if (Result) {
99    if (TargetTriple.getTriple().empty()) {
100      Triple TheTriple(Result->getTargetTriple());
101
102      if (TheTriple.getTriple().empty())
103        TheTriple.setTriple(sys::getDefaultTargetTriple());
104
105      TargetTriple.setTriple(TheTriple.getTriple());
106    }
107
108    Result->setTargetTriple(TargetTriple.getTriple());  // override the triple
109  }
110  return Result;
111}
112
113// This method takes the specified list of LLVM input files, attempts to load
114// them, either as assembly or bitcode, then link them together. It returns
115// true on failure (if, for example, an input bitcode file could not be
116// parsed), and false on success.
117//
118bool BugDriver::addSources(const std::vector<std::string> &Filenames) {
119  assert(!Program && "Cannot call addSources multiple times!");
120  assert(!Filenames.empty() && "Must specify at least on input filename!");
121
122  // Load the first input file.
123  Program = ParseInputFile(Filenames[0], Context);
124  if (!Program) return true;
125
126  outs() << "Read input file      : '" << Filenames[0] << "'\n";
127
128  for (unsigned i = 1, e = Filenames.size(); i != e; ++i) {
129    std::unique_ptr<Module> M(ParseInputFile(Filenames[i], Context));
130    if (!M.get()) return true;
131
132    outs() << "Linking in input file: '" << Filenames[i] << "'\n";
133    std::string ErrorMessage;
134    if (Linker::LinkModules(Program, M.get(), Linker::DestroySource,
135                            &ErrorMessage)) {
136      errs() << ToolName << ": error linking in '" << Filenames[i] << "': "
137             << ErrorMessage << '\n';
138      return true;
139    }
140  }
141
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///
153bool BugDriver::run(std::string &ErrMsg) {
154  if (run_find_bugs) {
155    // Rearrange the passes and apply them to the program. Repeat this process
156    // until the user kills the program or we find a bug.
157    return runManyPasses(PassesToRun, ErrMsg);
158  }
159
160  // If we're not running as a child, the first thing that we must do is
161  // determine what the problem is. Does the optimization series crash the
162  // compiler, or does it produce illegal code?  We make the top-level
163  // decision by trying to run all of the passes on the input program,
164  // which should generate a bitcode file.  If it does generate a bitcode
165  // file, then we know the compiler didn't crash, so try to diagnose a
166  // miscompilation.
167  if (!PassesToRun.empty()) {
168    outs() << "Running selected passes on program to test for crash: ";
169    if (runPasses(Program, PassesToRun))
170      return debugOptimizerCrash();
171  }
172
173  // Set up the execution environment, selecting a method to run LLVM bitcode.
174  if (initializeExecutionEnvironment()) return true;
175
176  // Test to see if we have a code generator crash.
177  outs() << "Running the code generator to test for a crash: ";
178  std::string Error;
179  compileProgram(Program, &Error);
180  if (!Error.empty()) {
181    outs() << Error;
182    return debugCodeGeneratorCrash(ErrMsg);
183  }
184  outs() << '\n';
185
186  // Run the raw input to see where we are coming from.  If a reference output
187  // was specified, make sure that the raw output matches it.  If not, it's a
188  // problem in the front-end or the code generator.
189  //
190  bool CreatedOutput = false;
191  if (ReferenceOutputFile.empty()) {
192    outs() << "Generating reference output from raw program: ";
193    if (!createReferenceFile(Program)) {
194      return debugCodeGeneratorCrash(ErrMsg);
195    }
196    CreatedOutput = true;
197  }
198
199  // Make sure the reference output file gets deleted on exit from this
200  // function, if appropriate.
201  std::string ROF(ReferenceOutputFile);
202  FileRemover RemoverInstance(ROF, CreatedOutput && !SaveTemps);
203
204  // Diff the output of the raw program against the reference output.  If it
205  // matches, then we assume there is a miscompilation bug and try to
206  // diagnose it.
207  outs() << "*** Checking the code generator...\n";
208  bool Diff = diffProgram(Program, "", "", false, &Error);
209  if (!Error.empty()) {
210    errs() << Error;
211    return debugCodeGeneratorCrash(ErrMsg);
212  }
213  if (!Diff) {
214    outs() << "\n*** Output matches: Debugging miscompilation!\n";
215    debugMiscompilation(&Error);
216    if (!Error.empty()) {
217      errs() << Error;
218      return debugCodeGeneratorCrash(ErrMsg);
219    }
220    return false;
221  }
222
223  outs() << "\n*** Input program does not match reference diff!\n";
224  outs() << "Debugging code generator problem!\n";
225  bool Failure = debugCodeGenerator(&Error);
226  if (!Error.empty()) {
227    errs() << Error;
228    return debugCodeGeneratorCrash(ErrMsg);
229  }
230  return Failure;
231}
232
233void llvm::PrintFunctionList(const std::vector<Function*> &Funcs) {
234  unsigned NumPrint = Funcs.size();
235  if (NumPrint > 10) NumPrint = 10;
236  for (unsigned i = 0; i != NumPrint; ++i)
237    outs() << " " << Funcs[i]->getName();
238  if (NumPrint < Funcs.size())
239    outs() << "... <" << Funcs.size() << " total>";
240  outs().flush();
241}
242
243void llvm::PrintGlobalVariableList(const std::vector<GlobalVariable*> &GVs) {
244  unsigned NumPrint = GVs.size();
245  if (NumPrint > 10) NumPrint = 10;
246  for (unsigned i = 0; i != NumPrint; ++i)
247    outs() << " " << GVs[i]->getName();
248  if (NumPrint < GVs.size())
249    outs() << "... <" << GVs.size() << " total>";
250  outs().flush();
251}
252