lib/Analysis/DbgInfoPrinter.cpp

   1 //===- DbgInfoPrinter.cpp - Print debug info in a human readable form ------==//
   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 file implements a pass that prints instructions, and associated debug
  11 // info:
  12 //
  13 //   - source/line/col information
  14 //   - original variable name
  15 //   - original type name
  16 //
  17 //===----------------------------------------------------------------------===//
  18
  19 #include "llvm/Pass.h"
  20 #include "llvm/Function.h"
  21 #include "llvm/IntrinsicInst.h"
  22 #include "llvm/Metadata.h"
  23 #include "llvm/Module.h"
  24 #include "llvm/Assembly/Writer.h"
  25 #include "llvm/Analysis/DebugInfo.h"
  26 #include "llvm/Analysis/Passes.h"
  27 #include "llvm/Support/CFG.h"
  28 #include "llvm/Support/CommandLine.h"
  29 #include "llvm/Support/raw_ostream.h"
  30
  31 using namespace llvm;
  32
  33 static cl::opt<bool>
  34 PrintDirectory("print-fullpath",
  35                cl::desc("Print fullpath when printing debug info"),
  36                cl::Hidden);
  37
  38 namespace {
  39   class PrintDbgInfo : public FunctionPass {
  40     raw_ostream &Out;
  41     void printVariableDeclaration(const Value *V);
  42   public:
  43     static char ID; // Pass identification
  44     PrintDbgInfo() : FunctionPass(ID), Out(errs()) {
  45       initializePrintDbgInfoPass(*PassRegistry::getPassRegistry());
  46     }
  47
  48     virtual bool runOnFunction(Function &F);
  49     virtual void getAnalysisUsage(AnalysisUsage &AU) const {
  50       AU.setPreservesAll();
  51     }
  52   };
  53   char PrintDbgInfo::ID = 0;
  54 }
  55
  56 INITIALIZE_PASS(PrintDbgInfo, "print-dbginfo",
  57                 "Print debug info in human readable form", false, false)
  58
  59 FunctionPass *llvm::createDbgInfoPrinterPass() { return new PrintDbgInfo(); }
  60
  61 /// Find the debug info descriptor corresponding to this global variable.
  62 static Value *findDbgGlobalDeclare(GlobalVariable *V) {
  63   const Module *M = V->getParent();
  64   NamedMDNode *NMD = M->getNamedMetadata("llvm.dbg.gv");
  65   if (!NMD)
  66     return 0;
  67
  68   for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i) {
  69     DIDescriptor DIG(cast<MDNode>(NMD->getOperand(i)));
  70     if (!DIG.isGlobalVariable())
  71       continue;
  72     if (DIGlobalVariable(DIG).getGlobal() == V)
  73       return DIG;
  74   }
  75   return 0;
  76 }
  77
  78 /// Find the debug info descriptor corresponding to this function.
  79 static Value *findDbgSubprogramDeclare(Function *V) {
  80   const Module *M = V->getParent();
  81   NamedMDNode *NMD = M->getNamedMetadata("llvm.dbg.sp");
  82   if (!NMD)
  83     return 0;
  84
  85   for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i) {
  86     DIDescriptor DIG(cast<MDNode>(NMD->getOperand(i)));
  87     if (!DIG.isSubprogram())
  88       continue;
  89     if (DISubprogram(DIG).getFunction() == V)
  90       return DIG;
  91   }
  92   return 0;
  93 }
  94
  95 /// Finds the llvm.dbg.declare intrinsic corresponding to this value if any.
  96 /// It looks through pointer casts too.
  97 static const DbgDeclareInst *findDbgDeclare(const Value *V) {
  98   V = V->stripPointerCasts();
  99
 100   if (!isa<Instruction>(V) && !isa<Argument>(V))
 101     return 0;
 102
 103   const Function *F = NULL;
 104   if (const Instruction *I = dyn_cast<Instruction>(V))
 105     F = I->getParent()->getParent();
 106   else if (const Argument *A = dyn_cast<Argument>(V))
 107     F = A->getParent();
 108
 109   for (Function::const_iterator FI = F->begin(), FE = F->end(); FI != FE; ++FI)
 110     for (BasicBlock::const_iterator BI = (*FI).begin(), BE = (*FI).end();
 111          BI != BE; ++BI)
 112       if (const DbgDeclareInst *DDI = dyn_cast<DbgDeclareInst>(BI))
 113         if (DDI->getAddress() == V)
 114           return DDI;
 115
 116   return 0;
 117 }
 118
 119 static bool getLocationInfo(const Value *V, std::string &DisplayName,
 120                             std::string &Type, unsigned &LineNo,
 121                             std::string &File, std::string &Dir) {
 122   DICompileUnit Unit;
 123   DIType TypeD;
 124
 125   if (GlobalVariable *GV = dyn_cast<GlobalVariable>(const_cast<Value*>(V))) {
 126     Value *DIGV = findDbgGlobalDeclare(GV);
 127     if (!DIGV) return false;
 128     DIGlobalVariable Var(cast<MDNode>(DIGV));
 129
 130     StringRef D = Var.getDisplayName();
 131     if (!D.empty())
 132       DisplayName = D;
 133     LineNo = Var.getLineNumber();
 134     Unit = Var.getCompileUnit();
 135     TypeD = Var.getType();
 136   } else if (Function *F = dyn_cast<Function>(const_cast<Value*>(V))){
 137     Value *DIF = findDbgSubprogramDeclare(F);
 138     if (!DIF) return false;
 139     DISubprogram Var(cast<MDNode>(DIF));
 140
 141     StringRef D = Var.getDisplayName();
 142     if (!D.empty())
 143       DisplayName = D;
 144     LineNo = Var.getLineNumber();
 145     Unit = Var.getCompileUnit();
 146     TypeD = Var.getType();
 147   } else {
 148     const DbgDeclareInst *DDI = findDbgDeclare(V);
 149     if (!DDI) return false;
 150     DIVariable Var(cast<MDNode>(DDI->getVariable()));
 151
 152     StringRef D = Var.getName();
 153     if (!D.empty())
 154       DisplayName = D;
 155     LineNo = Var.getLineNumber();
 156     Unit = Var.getCompileUnit();
 157     TypeD = Var.getType();
 158   }
 159
 160   StringRef T = TypeD.getName();
 161   if (!T.empty())
 162     Type = T;
 163   StringRef F = Unit.getFilename();
 164   if (!F.empty())
 165     File = F;
 166   StringRef D = Unit.getDirectory();
 167   if (!D.empty())
 168     Dir = D;
 169   return true;
 170 }
 171
 172 void PrintDbgInfo::printVariableDeclaration(const Value *V) {
 173   std::string DisplayName, File, Directory, Type;
 174   unsigned LineNo;
 175
 176   if (!getLocationInfo(V, DisplayName, Type, LineNo, File, Directory))
 177     return;
 178
 179   Out << "; ";
 180   WriteAsOperand(Out, V, false, 0);
 181   if (isa<Function>(V))
 182     Out << " is function " << DisplayName
 183         << " of type " << Type << " declared at ";
 184   else
 185     Out << " is variable " << DisplayName
 186         << " of type " << Type << " declared at ";
 187
 188   if (PrintDirectory)
 189     Out << Directory << "/";
 190
 191   Out << File << ":" << LineNo << "\n";
 192 }
 193
 194 bool PrintDbgInfo::runOnFunction(Function &F) {
 195   if (F.isDeclaration())
 196     return false;
 197
 198   Out << "function " << F.getName() << "\n\n";
 199
 200   for (Function::iterator I = F.begin(), E = F.end(); I != E; ++I) {
 201     BasicBlock *BB = I;
 202
 203     if (I != F.begin() && (pred_begin(BB) == pred_end(BB)))
 204       // Skip dead blocks.
 205       continue;
 206
 207     Out << BB->getName();
 208     Out << ":";
 209
 210     Out << "\n";
 211
 212     for (BasicBlock::const_iterator i = BB->begin(), e = BB->end();
 213          i != e; ++i) {
 214
 215         printVariableDeclaration(i);
 216
 217         if (const User *U = dyn_cast<User>(i)) {
 218           for(unsigned i=0;i<U->getNumOperands();i++)
 219             printVariableDeclaration(U->getOperand(i));
 220         }
 221     }
 222   }
 223   return false;
 224 }