1 //===- BugDriver.cpp - Top-Level BugPoint class implementation ------------===//
2 //
3 // This class contains all of the shared state and information that is used by
4 // the BugPoint tool to track down errors in optimizations.  This class is the
5 // main driver class that invokes all sub-functionality.
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "BugDriver.h"
10 #include "llvm/Module.h"
11 #include "llvm/Bytecode/Reader.h"
12 #include "llvm/Assembly/Parser.h"
13 #include "llvm/Transforms/Utils/Linker.h"
14 #include "llvm/Pass.h"
15 #include <memory>
16 
17 /// getPassesString - Turn a list of passes into a string which indicates the
18 /// command line options that must be passed to add the passes.
19 ///
20 std::string getPassesString(const std::vector<const PassInfo*> &Passes) {
21   std::string Result;
22   for (unsigned i = 0, e = Passes.size(); i != e; ++i) {
23     if (i) Result += " ";
24     Result += "-";
25     Result += Passes[i]->getPassArgument();
26   }
27   return Result;
28 }
29 
30 // DeleteFunctionBody - "Remove" the function by deleting all of its basic
31 // blocks, making it external.
32 //
33 void DeleteFunctionBody(Function *F) {
34   // First, break circular use/def chain references...
35   for (Function::iterator I = F->begin(), E = F->end(); I != E; ++I)
36     I->dropAllReferences();
37 
38   // Next, delete all of the basic blocks.
39   F->getBasicBlockList().clear();
40   F->setLinkage(GlobalValue::ExternalLinkage);
41   assert(F->isExternal() && "This didn't make the function external!");
42 }
43 
44 /// ParseInputFile - Given a bytecode or assembly input filename, parse and
45 /// return it, or return null if not possible.
46 ///
47 Module *BugDriver::ParseInputFile(const std::string &InputFilename) const {
48   Module *Result = 0;
49   try {
50     Result = ParseBytecodeFile(InputFilename);
51     if (!Result && !(Result = ParseAssemblyFile(InputFilename))){
52       std::cerr << ToolName << ": could not read input file '"
53                 << InputFilename << "'!\n";
54     }
55   } catch (const ParseException &E) {
56     std::cerr << ToolName << ": " << E.getMessage() << "\n";
57     Result = 0;
58   }
59   return Result;
60 }
61 
62 // This method takes the specified list of LLVM input files, attempts to load
63 // them, either as assembly or bytecode, then link them together. It returns
64 // true on failure (if, for example, an input bytecode file could not be
65 // parsed), and false on success.
66 //
67 bool BugDriver::addSources(const std::vector<std::string> &Filenames) {
68   assert(Program == 0 && "Cannot call addSources multiple times!");
69   assert(!Filenames.empty() && "Must specify at least on input filename!");
70 
71   // Load the first input file...
72   Program = ParseInputFile(Filenames[0]);
73   if (Program == 0) return true;
74   std::cout << "Read input file      : '" << Filenames[0] << "'\n";
75 
76   for (unsigned i = 1, e = Filenames.size(); i != e; ++i) {
77     std::auto_ptr<Module> M(ParseInputFile(Filenames[i]));
78     if (M.get() == 0) return true;
79 
80     std::cout << "Linking in input file: '" << Filenames[i] << "'\n";
81     std::string ErrorMessage;
82     if (LinkModules(Program, M.get(), &ErrorMessage)) {
83       std::cerr << ToolName << ": error linking in '" << Filenames[i] << "': "
84                 << ErrorMessage << "\n";
85       return true;
86     }
87   }
88 
89   std::cout << "*** All input ok\n";
90 
91   // All input files read successfully!
92   return false;
93 }
94 
95 
96 
97 /// run - The top level method that is invoked after all of the instance
98 /// variables are set up from command line arguments.
99 ///
100 bool BugDriver::run() {
101   // The first thing that we must do is determine what the problem is.  Does the
102   // optimization series crash the compiler, or does it produce illegal code? We
103   // make the top-level decision by trying to run all of the passes on the the
104   // input program, which should generate a bytecode file.  If it does generate
105   // a bytecode file, then we know the compiler didn't crash, so try to diagnose
106   // a miscompilation.
107   //
108   std::cout << "Running selected passes on program to test for crash: ";
109   if (runPasses(PassesToRun))
110     return debugCrash();
111   else
112     return debugMiscompilation();
113 }
114