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Diffstat (limited to 'lib/MC/MCObjectDisassembler.cpp')
| -rw-r--r-- | lib/MC/MCObjectDisassembler.cpp | 216 |
1 files changed, 216 insertions, 0 deletions
diff --git a/lib/MC/MCObjectDisassembler.cpp b/lib/MC/MCObjectDisassembler.cpp new file mode 100644 index 0000000000..bb3de1779e --- /dev/null +++ b/lib/MC/MCObjectDisassembler.cpp @@ -0,0 +1,216 @@ +//===- lib/MC/MCObjectDisassembler.cpp ------------------------------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// + +#include "llvm/MC/MCObjectDisassembler.h" +#include "llvm/ADT/STLExtras.h" +#include "llvm/ADT/SetVector.h" +#include "llvm/ADT/StringExtras.h" +#include "llvm/ADT/StringRef.h" +#include "llvm/ADT/Twine.h" +#include "llvm/MC/MCAtom.h" +#include "llvm/MC/MCDisassembler.h" +#include "llvm/MC/MCFunction.h" +#include "llvm/MC/MCInstrAnalysis.h" +#include "llvm/MC/MCModule.h" +#include "llvm/Object/ObjectFile.h" +#include "llvm/Support/MemoryObject.h" +#include "llvm/Support/StringRefMemoryObject.h" +#include "llvm/Support/raw_ostream.h" +#include <map> +#include <set> + +using namespace llvm; +using namespace object; + +MCObjectDisassembler::MCObjectDisassembler(const ObjectFile &Obj, + const MCDisassembler &Dis, + const MCInstrAnalysis &MIA) + : Obj(Obj), Dis(Dis), MIA(MIA) {} + +MCModule *MCObjectDisassembler::buildModule(bool withCFG) { + MCModule *Module = new MCModule; + buildSectionAtoms(Module); + if (withCFG) + buildCFG(Module); + return Module; +} + +void MCObjectDisassembler::buildSectionAtoms(MCModule *Module) { + error_code ec; + for (section_iterator SI = Obj.begin_sections(), + SE = Obj.end_sections(); + SI != SE; + SI.increment(ec)) { + if (ec) break; + + bool isText; SI->isText(isText); + bool isData; SI->isData(isData); + if (!isData && !isText) + continue; + + uint64_t StartAddr; SI->getAddress(StartAddr); + uint64_t SecSize; SI->getSize(SecSize); + if (StartAddr == UnknownAddressOrSize || SecSize == UnknownAddressOrSize) + continue; + + StringRef Contents; SI->getContents(Contents); + StringRefMemoryObject memoryObject(Contents); + + // We don't care about things like non-file-backed sections yet. + if (Contents.size() != SecSize || !SecSize) + continue; + uint64_t EndAddr = StartAddr + SecSize - 1; + + StringRef SecName; SI->getName(SecName); + + if (isText) { + MCTextAtom *Text = Module->createTextAtom(StartAddr, EndAddr); + Text->setName(SecName); + uint64_t InstSize; + for (uint64_t Index = 0; Index < SecSize; Index += InstSize) { + MCInst Inst; + if (Dis.getInstruction(Inst, InstSize, memoryObject, Index, + nulls(), nulls())) + Text->addInst(Inst, InstSize); + else + // We don't care about splitting mixed atoms either. + llvm_unreachable("Couldn't disassemble instruction in atom."); + } + + } else { + MCDataAtom *Data = Module->createDataAtom(StartAddr, EndAddr); + Data->setName(SecName); + for (uint64_t Index = 0; Index < SecSize; ++Index) + Data->addData(Contents[Index]); + } + } +} + +namespace { + struct BBInfo; + typedef std::set<BBInfo*> BBInfoSetTy; + + struct BBInfo { + MCTextAtom *Atom; + MCBasicBlock *BB; + BBInfoSetTy Succs; + BBInfoSetTy Preds; + + void addSucc(BBInfo &Succ) { + Succs.insert(&Succ); + Succ.Preds.insert(this); + } + }; +} + +void MCObjectDisassembler::buildCFG(MCModule *Module) { + typedef std::map<uint64_t, BBInfo> BBInfoByAddrTy; + BBInfoByAddrTy BBInfos; + typedef std::set<uint64_t> AddressSetTy; + AddressSetTy Splits; + AddressSetTy Calls; + + assert(Module->func_begin() == Module->func_end() + && "Module already has a CFG!"); + + // First, determine the basic block boundaries and call targets. + for (MCModule::atom_iterator AI = Module->atom_begin(), + AE = Module->atom_end(); + AI != AE; ++AI) { + MCTextAtom *TA = dyn_cast<MCTextAtom>(*AI); + if (!TA) continue; + Calls.insert(TA->getBeginAddr()); + for (MCTextAtom::const_iterator II = TA->begin(), IE = TA->end(); + II != IE; ++II) { + if (MIA.isTerminator(II->Inst)) + Splits.insert(II->Address + II->Size); + uint64_t Target; + if (MIA.evaluateBranch(II->Inst, II->Address, II->Size, Target)) { + if (MIA.isCall(II->Inst)) + Calls.insert(Target); + Splits.insert(Target); + } + } + } + + // Split text atoms into basic block atoms. + for (AddressSetTy::const_iterator SI = Splits.begin(), SE = Splits.end(); + SI != SE; ++SI) { + MCAtom *A = Module->findAtomContaining(*SI); + if (!A) continue; + MCTextAtom *TA = cast<MCTextAtom>(A); + BBInfos[TA->getBeginAddr()].Atom = TA; + if (TA->getBeginAddr() == *SI) + continue; + MCTextAtom *NewAtom = TA->split(*SI); + BBInfos[NewAtom->getBeginAddr()].Atom = NewAtom; + StringRef BBName = TA->getName(); + BBName = BBName.substr(0, BBName.find_last_of(':')); + NewAtom->setName((BBName + ":" + utohexstr(*SI)).str()); + } + + // Compute succs/preds. + for (MCModule::atom_iterator AI = Module->atom_begin(), + AE = Module->atom_end(); + AI != AE; ++AI) { + MCTextAtom *TA = dyn_cast<MCTextAtom>(*AI); + if (!TA) continue; + BBInfo &CurBB = BBInfos[TA->getBeginAddr()]; + const MCDecodedInst &LI = TA->back(); + if (MIA.isBranch(LI.Inst)) { + uint64_t Target; + if (MIA.evaluateBranch(LI.Inst, LI.Address, LI.Size, Target)) + CurBB.addSucc(BBInfos[Target]); + if (MIA.isConditionalBranch(LI.Inst)) + CurBB.addSucc(BBInfos[LI.Address + LI.Size]); + } else if (!MIA.isTerminator(LI.Inst)) + CurBB.addSucc(BBInfos[LI.Address + LI.Size]); + } + + + // Create functions and basic blocks. + for (AddressSetTy::const_iterator CI = Calls.begin(), CE = Calls.end(); + CI != CE; ++CI) { + BBInfo &BBI = BBInfos[*CI]; + if (!BBI.Atom) continue; + + MCFunction &MCFN = *Module->createFunction(BBI.Atom->getName()); + + // Create MCBBs. + SmallSetVector<BBInfo*, 16> Worklist; + Worklist.insert(&BBI); + for (size_t WI = 0; WI < Worklist.size(); ++WI) { + BBInfo *BBI = Worklist[WI]; + if (!BBI->Atom) + continue; + BBI->BB = &MCFN.createBlock(*BBI->Atom); + // Add all predecessors and successors to the worklist. + for (BBInfoSetTy::iterator SI = BBI->Succs.begin(), SE = BBI->Succs.end(); + SI != SE; ++SI) + Worklist.insert(*SI); + for (BBInfoSetTy::iterator PI = BBI->Preds.begin(), PE = BBI->Preds.end(); + PI != PE; ++PI) + Worklist.insert(*PI); + } + + // Set preds/succs. + for (size_t WI = 0; WI < Worklist.size(); ++WI) { + BBInfo *BBI = Worklist[WI]; + MCBasicBlock *MCBB = BBI->BB; + if (!MCBB) + continue; + for (BBInfoSetTy::iterator SI = BBI->Succs.begin(), SE = BBI->Succs.end(); + SI != SE; ++SI) + MCBB->addSuccessor((*SI)->BB); + for (BBInfoSetTy::iterator PI = BBI->Preds.begin(), PE = BBI->Preds.end(); + PI != PE; ++PI) + MCBB->addPredecessor((*PI)->BB); + } + } +} |