FindBugs.cpp revision 032091d7f62774443c282915964189ea3d8930de 
1//===-- FindBugs.cpp - Run Many Different Optimizations -------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file was developed by Patrick Jenkins and is distributed under
6// the University of Illinois Open Source License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file defines an interface that allows bugpoint to choose different
11// combinations of optimizations to run on the selected input. Bugpoint will
12// run these optimizations and record the success/failure of each. This way
13// we can hopefully spot bugs in the optimizations.
14//
15//===----------------------------------------------------------------------===//
16#include "BugDriver.h"
17#include "ToolRunner.h"
18
19#include "llvm/Bytecode/WriteBytecodePass.h"
20
21#include <algorithm>
22#include <ctime>
23using namespace llvm;
24
25/// runManyPasses - Take the specified pass list and create different
26/// combinations of passes to compile the program with. Compile the program with
27/// each set and mark test to see if it compiled correctly. If the passes
28/// compiled correctly output nothing and rearrange the passes into a new order.
29/// If the passes did not compile correctly, output the command required to
30/// recreate the failure. This returns true if a compiler error is found.
31///
32bool BugDriver::runManyPasses(const std::vector<const PassInfo*> &AllPasses)
33{
34  std::string Filename;
35  std::vector<const PassInfo*> TempPass(AllPasses);
36  std::cout << "Starting bug finding procedure...\n\n";
37
38  // Creating a reference output if necessary
39  if (initializeExecutionEnvironment()) return false;
40  std::cout << "\n";
41  if (ReferenceOutputFile.empty()) {
42  	std::cout << "Generating reference output from raw program: \n";
43	  if(!createReferenceFile(Program)){
44	  	return false;
45	  }
46  }
47
48  srand(time(NULL));
49  std::vector<const PassInfo*>::iterator I = TempPass.begin();
50  std::vector<const PassInfo*>::iterator E = TempPass.end();
51
52	int num=1;
53  while(1){
54    //
55    // Step 1: Randomize the order of the optimizer passes.
56    //
57    std::random_shuffle(TempPass.begin(), TempPass.end());
58
59    //
60    // Step 2: Run optimizer passes on the program and check for success.
61    //
62    std::cout << "Running selected passes on program to test for crash: ";
63    for(int i=0, e=TempPass.size(); i!=e; i++) {
64      std::cout << "-" << TempPass[i]->getPassArgument( )<< " ";
65    }
66    std::string Filename;
67    if(runPasses(TempPass, Filename, false)) {
68      std::cout << "\n";
69      std::cout << "Optimizer passes caused failure!\n\n";
70      debugOptimizerCrash();
71      return true;
72    }
73    else{
74     std::cout << "Combination "<<num<<" optimized successfully!\n";
75    }
76
77    //
78    // Step 3: Compile the optimized code.
79    //
80    std::cout << "Running the code generator to test for a crash: ";
81    try {
82      compileProgram(Program);
83      std::cout << '\n';
84    } catch (ToolExecutionError &TEE) {
85      std::cout << "\n*** compileProgram threw an exception: ";
86      std::cout << TEE.what();
87      return debugCodeGeneratorCrash();
88    }
89
90    //
91    // Step 4: Run the program and compare its output to the reference
92    // output (created above).
93    //
94    std::cout << "*** Checking if passes caused miscompliation:\n";
95    try {
96      if (diffProgram(Filename, "", false)) {
97        std::cout << "\n*** diffProgram returned true!\n";
98        debugMiscompilation();
99        return true;
100      }
101      else{
102        std::cout << "\n*** diff'd output matches!\n";
103      }
104    } catch (ToolExecutionError &TEE) {
105      std::cerr << TEE.what();
106      debugCodeGeneratorCrash();
107      return true;
108    }
109
110    sys::Path(Filename).eraseFromDisk();
111
112    std::cout << "\n\n";
113    num++;
114  } //end while
115
116  // This will never be reached
117  std::cout << "Did not find any bugs :-( \n";
118  return false;
119}
120