1 //===- lib/MC/MCObjectDisassembler.cpp ------------------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 #include "llvm/MC/MCObjectDisassembler.h"
11 #include "llvm/ADT/SetVector.h"
12 #include "llvm/ADT/SmallPtrSet.h"
13 #include "llvm/ADT/StringExtras.h"
14 #include "llvm/ADT/StringRef.h"
15 #include "llvm/ADT/Twine.h"
16 #include "llvm/MC/MCAtom.h"
17 #include "llvm/MC/MCDisassembler.h"
18 #include "llvm/MC/MCFunction.h"
19 #include "llvm/MC/MCInstrAnalysis.h"
20 #include "llvm/MC/MCModule.h"
21 #include "llvm/MC/MCObjectSymbolizer.h"
22 #include "llvm/Object/MachO.h"
23 #include "llvm/Object/ObjectFile.h"
24 #include "llvm/Support/Debug.h"
25 #include "llvm/Support/MachO.h"
26 #include "llvm/Support/MemoryObject.h"
27 #include "llvm/Support/StringRefMemoryObject.h"
28 #include "llvm/Support/raw_ostream.h"
33 using namespace object;
35 MCObjectDisassembler::MCObjectDisassembler(const ObjectFile &Obj,
36 const MCDisassembler &Dis,
37 const MCInstrAnalysis &MIA)
38 : Obj(Obj), Dis(Dis), MIA(MIA), MOS(0) {}
40 uint64_t MCObjectDisassembler::getEntrypoint() {
42 for (symbol_iterator SI = Obj.begin_symbols(), SE = Obj.end_symbols();
43 SI != SE; SI.increment(ec)) {
48 if (Name == "main" || Name == "_main") {
50 SI->getAddress(Entrypoint);
51 return getEffectiveLoadAddr(Entrypoint);
57 ArrayRef<uint64_t> MCObjectDisassembler::getStaticInitFunctions() {
58 return ArrayRef<uint64_t>();
61 ArrayRef<uint64_t> MCObjectDisassembler::getStaticExitFunctions() {
62 return ArrayRef<uint64_t>();
65 uint64_t MCObjectDisassembler::getEffectiveLoadAddr(uint64_t Addr) {
69 uint64_t MCObjectDisassembler::getOriginalLoadAddr(uint64_t Addr) {
73 MCModule *MCObjectDisassembler::buildEmptyModule() {
74 MCModule *Module = new MCModule;
75 Module->Entrypoint = getEntrypoint();
79 MCModule *MCObjectDisassembler::buildModule(bool withCFG) {
80 MCModule *Module = buildEmptyModule();
82 buildSectionAtoms(Module);
88 void MCObjectDisassembler::buildSectionAtoms(MCModule *Module) {
90 for (section_iterator SI = Obj.begin_sections(),
91 SE = Obj.end_sections();
96 bool isText; SI->isText(isText);
97 bool isData; SI->isData(isData);
98 if (!isData && !isText)
101 uint64_t StartAddr; SI->getAddress(StartAddr);
102 uint64_t SecSize; SI->getSize(SecSize);
103 if (StartAddr == UnknownAddressOrSize || SecSize == UnknownAddressOrSize)
105 StartAddr = getEffectiveLoadAddr(StartAddr);
107 StringRef Contents; SI->getContents(Contents);
108 StringRefMemoryObject memoryObject(Contents, StartAddr);
110 // We don't care about things like non-file-backed sections yet.
111 if (Contents.size() != SecSize || !SecSize)
113 uint64_t EndAddr = StartAddr + SecSize - 1;
115 StringRef SecName; SI->getName(SecName);
118 MCTextAtom *Text = 0;
119 MCDataAtom *InvalidData = 0;
122 for (uint64_t Index = 0; Index < SecSize; Index += InstSize) {
123 const uint64_t CurAddr = StartAddr + Index;
125 if (Dis.getInstruction(Inst, InstSize, memoryObject, CurAddr, nulls(),
128 Text = Module->createTextAtom(CurAddr, CurAddr);
129 Text->setName(SecName);
131 Text->addInst(Inst, InstSize);
136 InvalidData = Module->createDataAtom(CurAddr, EndAddr);
138 InvalidData->addData(Contents[Index]);
142 MCDataAtom *Data = Module->createDataAtom(StartAddr, EndAddr);
143 Data->setName(SecName);
144 for (uint64_t Index = 0; Index < SecSize; ++Index)
145 Data->addData(Contents[Index]);
152 typedef SmallPtrSet<BBInfo*, 2> BBInfoSetTy;
160 BBInfo() : Atom(0), BB(0) {}
162 void addSucc(BBInfo &Succ) {
164 Succ.Preds.insert(this);
169 void MCObjectDisassembler::buildCFG(MCModule *Module) {
170 typedef std::map<uint64_t, BBInfo> BBInfoByAddrTy;
171 BBInfoByAddrTy BBInfos;
172 typedef std::vector<uint64_t> AddressSetTy;
177 for (symbol_iterator SI = Obj.begin_symbols(), SE = Obj.end_symbols();
178 SI != SE; SI.increment(ec)) {
181 SymbolRef::Type SymType;
182 SI->getType(SymType);
183 if (SymType == SymbolRef::ST_Function) {
185 SI->getAddress(SymAddr);
186 SymAddr = getEffectiveLoadAddr(SymAddr);
187 Calls.push_back(SymAddr);
188 Splits.push_back(SymAddr);
192 assert(Module->func_begin() == Module->func_end()
193 && "Module already has a CFG!");
195 // First, determine the basic block boundaries and call targets.
196 for (MCModule::atom_iterator AI = Module->atom_begin(),
197 AE = Module->atom_end();
199 MCTextAtom *TA = dyn_cast<MCTextAtom>(*AI);
201 Calls.push_back(TA->getBeginAddr());
202 BBInfos[TA->getBeginAddr()].Atom = TA;
203 for (MCTextAtom::const_iterator II = TA->begin(), IE = TA->end();
205 if (MIA.isTerminator(II->Inst))
206 Splits.push_back(II->Address + II->Size);
208 if (MIA.evaluateBranch(II->Inst, II->Address, II->Size, Target)) {
209 if (MIA.isCall(II->Inst))
210 Calls.push_back(Target);
211 Splits.push_back(Target);
216 std::sort(Splits.begin(), Splits.end());
217 Splits.erase(std::unique(Splits.begin(), Splits.end()), Splits.end());
219 std::sort(Calls.begin(), Calls.end());
220 Calls.erase(std::unique(Calls.begin(), Calls.end()), Calls.end());
222 // Split text atoms into basic block atoms.
223 for (AddressSetTy::const_iterator SI = Splits.begin(), SE = Splits.end();
225 MCAtom *A = Module->findAtomContaining(*SI);
227 MCTextAtom *TA = cast<MCTextAtom>(A);
228 if (TA->getBeginAddr() == *SI)
230 MCTextAtom *NewAtom = TA->split(*SI);
231 BBInfos[NewAtom->getBeginAddr()].Atom = NewAtom;
232 StringRef BBName = TA->getName();
233 BBName = BBName.substr(0, BBName.find_last_of(':'));
234 NewAtom->setName((BBName + ":" + utohexstr(*SI)).str());
237 // Compute succs/preds.
238 for (MCModule::atom_iterator AI = Module->atom_begin(),
239 AE = Module->atom_end();
241 MCTextAtom *TA = dyn_cast<MCTextAtom>(*AI);
243 BBInfo &CurBB = BBInfos[TA->getBeginAddr()];
244 const MCDecodedInst &LI = TA->back();
245 if (MIA.isBranch(LI.Inst)) {
247 if (MIA.evaluateBranch(LI.Inst, LI.Address, LI.Size, Target))
248 CurBB.addSucc(BBInfos[Target]);
249 if (MIA.isConditionalBranch(LI.Inst))
250 CurBB.addSucc(BBInfos[LI.Address + LI.Size]);
251 } else if (!MIA.isTerminator(LI.Inst))
252 CurBB.addSucc(BBInfos[LI.Address + LI.Size]);
256 // Create functions and basic blocks.
257 for (AddressSetTy::const_iterator CI = Calls.begin(), CE = Calls.end();
259 BBInfo &BBI = BBInfos[*CI];
260 if (!BBI.Atom) continue;
262 MCFunction &MCFN = *Module->createFunction(BBI.Atom->getName());
265 SmallSetVector<BBInfo*, 16> Worklist;
266 Worklist.insert(&BBI);
267 for (size_t wi = 0; wi < Worklist.size(); ++wi) {
268 BBInfo *BBI = Worklist[wi];
271 BBI->BB = &MCFN.createBlock(*BBI->Atom);
272 // Add all predecessors and successors to the worklist.
273 for (BBInfoSetTy::iterator SI = BBI->Succs.begin(), SE = BBI->Succs.end();
275 Worklist.insert(*SI);
276 for (BBInfoSetTy::iterator PI = BBI->Preds.begin(), PE = BBI->Preds.end();
278 Worklist.insert(*PI);
282 for (size_t wi = 0; wi < Worklist.size(); ++wi) {
283 BBInfo *BBI = Worklist[wi];
284 MCBasicBlock *MCBB = BBI->BB;
287 for (BBInfoSetTy::iterator SI = BBI->Succs.begin(), SE = BBI->Succs.end();
290 MCBB->addSuccessor((*SI)->BB);
291 for (BBInfoSetTy::iterator PI = BBI->Preds.begin(), PE = BBI->Preds.end();
294 MCBB->addPredecessor((*PI)->BB);
299 // MachO MCObjectDisassembler implementation.
301 MCMachOObjectDisassembler::MCMachOObjectDisassembler(
302 const MachOObjectFile &MOOF, const MCDisassembler &Dis,
303 const MCInstrAnalysis &MIA, uint64_t VMAddrSlide,
304 uint64_t HeaderLoadAddress)
305 : MCObjectDisassembler(MOOF, Dis, MIA), MOOF(MOOF),
306 VMAddrSlide(VMAddrSlide), HeaderLoadAddress(HeaderLoadAddress) {
309 for (section_iterator SI = MOOF.begin_sections(), SE = MOOF.end_sections();
310 SI != SE; SI.increment(ec)) {
315 // FIXME: We should use the S_ section type instead of the name.
316 if (Name == "__mod_init_func") {
317 DEBUG(dbgs() << "Found __mod_init_func section!\n");
318 SI->getContents(ModInitContents);
319 } else if (Name == "__mod_exit_func") {
320 DEBUG(dbgs() << "Found __mod_exit_func section!\n");
321 SI->getContents(ModExitContents);
326 // FIXME: Only do the translations for addresses actually inside the object.
327 uint64_t MCMachOObjectDisassembler::getEffectiveLoadAddr(uint64_t Addr) {
328 return Addr + VMAddrSlide;
332 MCMachOObjectDisassembler::getOriginalLoadAddr(uint64_t EffectiveAddr) {
333 return EffectiveAddr - VMAddrSlide;
336 uint64_t MCMachOObjectDisassembler::getEntrypoint() {
337 uint64_t EntryFileOffset = 0;
341 uint32_t LoadCommandCount = MOOF.getHeader().NumLoadCommands;
342 MachOObjectFile::LoadCommandInfo Load = MOOF.getFirstLoadCommandInfo();
343 for (unsigned I = 0;; ++I) {
344 if (Load.C.Type == MachO::LoadCommandMain) {
346 ((const MachO::entry_point_command *)Load.Ptr)->entryoff;
350 if (I == LoadCommandCount - 1)
353 Load = MOOF.getNextLoadCommandInfo(Load);
357 // If we didn't find anything, default to the common implementation.
358 // FIXME: Maybe we could also look at LC_UNIXTHREAD and friends?
360 return MCObjectDisassembler::getEntrypoint();
362 return EntryFileOffset + HeaderLoadAddress;
365 ArrayRef<uint64_t> MCMachOObjectDisassembler::getStaticInitFunctions() {
366 // FIXME: We only handle 64bit mach-o
367 assert(MOOF.is64Bit());
369 size_t EntrySize = 8;
370 size_t EntryCount = ModInitContents.size() / EntrySize;
371 return ArrayRef<uint64_t>(
372 reinterpret_cast<const uint64_t *>(ModInitContents.data()), EntryCount);
375 ArrayRef<uint64_t> MCMachOObjectDisassembler::getStaticExitFunctions() {
376 // FIXME: We only handle 64bit mach-o
377 assert(MOOF.is64Bit());
379 size_t EntrySize = 8;
380 size_t EntryCount = ModExitContents.size() / EntrySize;
381 return ArrayRef<uint64_t>(
382 reinterpret_cast<const uint64_t *>(ModExitContents.data()), EntryCount);