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.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(0), Interpreter(0), SafeInterpreter(0), gcc(0),
74    run_find_bugs(find_bugs), Timeout(timeout),
75    MemoryLimit(memlimit), UseValgrind(use_valgrind) {}
76
77BugDriver::~BugDriver() {
78  delete Program;
79}
80
81
82/// ParseInputFile - Given a bitcode or assembly input filename, parse and
83/// return it, or return null if not possible.
84///
85Module *llvm::ParseInputFile(const std::string &Filename,
86                             LLVMContext& Ctxt) {
87  SMDiagnostic Err;
88  Module *Result = ParseIRFile(Filename, Err, Ctxt);
89  if (!Result)
90    Err.print("bugpoint", errs());
91
92  // If we don't have an override triple, use the first one to configure
93  // bugpoint, or use the host triple if none provided.
94  if (Result) {
95    if (TargetTriple.getTriple().empty()) {
96      Triple TheTriple(Result->getTargetTriple());
97
98      if (TheTriple.getTriple().empty())
99        TheTriple.setTriple(sys::getDefaultTargetTriple());
100
101      TargetTriple.setTriple(TheTriple.getTriple());
102    }
103
104    Result->setTargetTriple(TargetTriple.getTriple());  // override the triple
105  }
106  return Result;
107}
108
109// This method takes the specified list of LLVM input files, attempts to load
110// them, either as assembly or bitcode, then link them together. It returns
111// true on failure (if, for example, an input bitcode file could not be
112// parsed), and false on success.
113//
114bool BugDriver::addSources(const std::vector<std::string> &Filenames) {
115  assert(Program == 0 && "Cannot call addSources multiple times!");
116  assert(!Filenames.empty() && "Must specify at least on input filename!");
117
118  // Load the first input file.
119  Program = ParseInputFile(Filenames[0], Context);
120  if (Program == 0) return true;
121
122  outs() << "Read input file      : '" << Filenames[0] << "'\n";
123
124  for (unsigned i = 1, e = Filenames.size(); i != e; ++i) {
125    OwningPtr<Module> M(ParseInputFile(Filenames[i], Context));
126    if (M.get() == 0) return true;
127
128    outs() << "Linking in input file: '" << Filenames[i] << "'\n";
129    std::string ErrorMessage;
130    if (Linker::LinkModules(Program, M.get(), Linker::DestroySource,
131                            &ErrorMessage)) {
132      errs() << ToolName << ": error linking in '" << Filenames[i] << "': "
133             << ErrorMessage << '\n';
134      return true;
135    }
136  }
137
138  outs() << "*** All input ok\n";
139
140  // All input files read successfully!
141  return false;
142}
143
144
145
146/// run - The top level method that is invoked after all of the instance
147/// variables are set up from command line arguments.
148///
149bool BugDriver::run(std::string &ErrMsg) {
150  if (run_find_bugs) {
151    // Rearrange the passes and apply them to the program. Repeat this process
152    // until the user kills the program or we find a bug.
153    return runManyPasses(PassesToRun, ErrMsg);
154  }
155
156  // If we're not running as a child, the first thing that we must do is
157  // determine what the problem is. Does the optimization series crash the
158  // compiler, or does it produce illegal code?  We make the top-level
159  // decision by trying to run all of the passes on the input program,
160  // which should generate a bitcode file.  If it does generate a bitcode
161  // file, then we know the compiler didn't crash, so try to diagnose a
162  // miscompilation.
163  if (!PassesToRun.empty()) {
164    outs() << "Running selected passes on program to test for crash: ";
165    if (runPasses(Program, PassesToRun))
166      return debugOptimizerCrash();
167  }
168
169  // Set up the execution environment, selecting a method to run LLVM bitcode.
170  if (initializeExecutionEnvironment()) return true;
171
172  // Test to see if we have a code generator crash.
173  outs() << "Running the code generator to test for a crash: ";
174  std::string Error;
175  compileProgram(Program, &Error);
176  if (!Error.empty()) {
177    outs() << Error;
178    return debugCodeGeneratorCrash(ErrMsg);
179  }
180  outs() << '\n';
181
182  // Run the raw input to see where we are coming from.  If a reference output
183  // was specified, make sure that the raw output matches it.  If not, it's a
184  // problem in the front-end or the code generator.
185  //
186  bool CreatedOutput = false;
187  if (ReferenceOutputFile.empty()) {
188    outs() << "Generating reference output from raw program: ";
189    if (!createReferenceFile(Program)) {
190      return debugCodeGeneratorCrash(ErrMsg);
191    }
192    CreatedOutput = true;
193  }
194
195  // Make sure the reference output file gets deleted on exit from this
196  // function, if appropriate.
197  std::string ROF(ReferenceOutputFile);
198  FileRemover RemoverInstance(ROF, CreatedOutput && !SaveTemps);
199
200  // Diff the output of the raw program against the reference output.  If it
201  // matches, then we assume there is a miscompilation bug and try to
202  // diagnose it.
203  outs() << "*** Checking the code generator...\n";
204  bool Diff = diffProgram(Program, "", "", false, &Error);
205  if (!Error.empty()) {
206    errs() << Error;
207    return debugCodeGeneratorCrash(ErrMsg);
208  }
209  if (!Diff) {
210    outs() << "\n*** Output matches: Debugging miscompilation!\n";
211    debugMiscompilation(&Error);
212    if (!Error.empty()) {
213      errs() << Error;
214      return debugCodeGeneratorCrash(ErrMsg);
215    }
216    return false;
217  }
218
219  outs() << "\n*** Input program does not match reference diff!\n";
220  outs() << "Debugging code generator problem!\n";
221  bool Failure = debugCodeGenerator(&Error);
222  if (!Error.empty()) {
223    errs() << Error;
224    return debugCodeGeneratorCrash(ErrMsg);
225  }
226  return Failure;
227}
228
229void llvm::PrintFunctionList(const std::vector<Function*> &Funcs) {
230  unsigned NumPrint = Funcs.size();
231  if (NumPrint > 10) NumPrint = 10;
232  for (unsigned i = 0; i != NumPrint; ++i)
233    outs() << " " << Funcs[i]->getName();
234  if (NumPrint < Funcs.size())
235    outs() << "... <" << Funcs.size() << " total>";
236  outs().flush();
237}
238
239void llvm::PrintGlobalVariableList(const std::vector<GlobalVariable*> &GVs) {
240  unsigned NumPrint = GVs.size();
241  if (NumPrint > 10) NumPrint = 10;
242  for (unsigned i = 0; i != NumPrint; ++i)
243    outs() << " " << GVs[i]->getName();
244  if (NumPrint < GVs.size())
245    outs() << "... <" << GVs.size() << " total>";
246  outs().flush();
247}
248