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/STLExtras.h"
12 #include "llvm/ADT/SetVector.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/Object/MachO.h"
22 #include "llvm/Object/ObjectFile.h"
23 #include "llvm/Support/Debug.h"
24 #include "llvm/Support/MachO.h"
25 #include "llvm/Support/MemoryObject.h"
26 #include "llvm/Support/StringRefMemoryObject.h"
27 #include "llvm/Support/raw_ostream.h"
32 using namespace object;
34 MCObjectDisassembler::MCObjectDisassembler(const ObjectFile &Obj,
35 const MCDisassembler &Dis,
36 const MCInstrAnalysis &MIA)
37 : Obj(Obj), Dis(Dis), MIA(MIA) {}
39 uint64_t MCObjectDisassembler::getEntrypoint() {
41 for (symbol_iterator SI = Obj.begin_symbols(), SE = Obj.end_symbols();
42 SI != SE; SI.increment(ec)) {
47 if (Name == "main" || Name == "_main") {
49 SI->getAddress(Entrypoint);
50 return getEffectiveLoadAddr(Entrypoint);
56 ArrayRef<uint64_t> MCObjectDisassembler::getStaticInitFunctions() {
57 return ArrayRef<uint64_t>();
60 ArrayRef<uint64_t> MCObjectDisassembler::getStaticExitFunctions() {
61 return ArrayRef<uint64_t>();
64 uint64_t MCObjectDisassembler::getEffectiveLoadAddr(uint64_t Addr) {
68 uint64_t MCObjectDisassembler::getOriginalLoadAddr(uint64_t Addr) {
72 MCModule *MCObjectDisassembler::buildEmptyModule() {
73 MCModule *Module = new MCModule;
74 Module->Entrypoint = getEntrypoint();
78 MCModule *MCObjectDisassembler::buildModule(bool withCFG) {
79 MCModule *Module = buildEmptyModule();
81 buildSectionAtoms(Module);
87 void MCObjectDisassembler::buildSectionAtoms(MCModule *Module) {
89 for (section_iterator SI = Obj.begin_sections(),
90 SE = Obj.end_sections();
95 bool isText; SI->isText(isText);
96 bool isData; SI->isData(isData);
97 if (!isData && !isText)
100 uint64_t StartAddr; SI->getAddress(StartAddr);
101 uint64_t SecSize; SI->getSize(SecSize);
102 if (StartAddr == UnknownAddressOrSize || SecSize == UnknownAddressOrSize)
104 StartAddr = getEffectiveLoadAddr(StartAddr);
106 StringRef Contents; SI->getContents(Contents);
107 StringRefMemoryObject memoryObject(Contents, StartAddr);
109 // We don't care about things like non-file-backed sections yet.
110 if (Contents.size() != SecSize || !SecSize)
112 uint64_t EndAddr = StartAddr + SecSize - 1;
114 StringRef SecName; SI->getName(SecName);
117 MCTextAtom *Text = 0;
118 MCDataAtom *InvalidData = 0;
121 for (uint64_t Index = 0; Index < SecSize; Index += InstSize) {
122 const uint64_t CurAddr = StartAddr + Index;
124 if (Dis.getInstruction(Inst, InstSize, memoryObject, CurAddr, nulls(),
127 Text = Module->createTextAtom(CurAddr, CurAddr);
128 Text->setName(SecName);
130 Text->addInst(Inst, InstSize);
135 InvalidData = Module->createDataAtom(CurAddr, EndAddr);
137 InvalidData->addData(Contents[Index]);
141 MCDataAtom *Data = Module->createDataAtom(StartAddr, EndAddr);
142 Data->setName(SecName);
143 for (uint64_t Index = 0; Index < SecSize; ++Index)
144 Data->addData(Contents[Index]);
151 typedef std::set<BBInfo*> BBInfoSetTy;
159 BBInfo() : Atom(0), BB(0) {}
161 void addSucc(BBInfo &Succ) {
163 Succ.Preds.insert(this);
168 void MCObjectDisassembler::buildCFG(MCModule *Module) {
169 typedef std::map<uint64_t, BBInfo> BBInfoByAddrTy;
170 BBInfoByAddrTy BBInfos;
171 typedef std::set<uint64_t> AddressSetTy;
176 for (symbol_iterator SI = Obj.begin_symbols(), SE = Obj.end_symbols();
177 SI != SE; SI.increment(ec)) {
180 SymbolRef::Type SymType;
181 SI->getType(SymType);
182 if (SymType == SymbolRef::ST_Function) {
184 SI->getAddress(SymAddr);
185 SymAddr = getEffectiveLoadAddr(SymAddr);
186 Calls.insert(SymAddr);
187 Splits.insert(SymAddr);
191 assert(Module->func_begin() == Module->func_end()
192 && "Module already has a CFG!");
194 // First, determine the basic block boundaries and call targets.
195 for (MCModule::atom_iterator AI = Module->atom_begin(),
196 AE = Module->atom_end();
198 MCTextAtom *TA = dyn_cast<MCTextAtom>(*AI);
200 Calls.insert(TA->getBeginAddr());
201 BBInfos[TA->getBeginAddr()].Atom = TA;
202 for (MCTextAtom::const_iterator II = TA->begin(), IE = TA->end();
204 if (MIA.isTerminator(II->Inst))
205 Splits.insert(II->Address + II->Size);
207 if (MIA.evaluateBranch(II->Inst, II->Address, II->Size, Target)) {
208 if (MIA.isCall(II->Inst))
209 Calls.insert(Target);
210 Splits.insert(Target);
215 // Split text atoms into basic block atoms.
216 for (AddressSetTy::const_iterator SI = Splits.begin(), SE = Splits.end();
218 MCAtom *A = Module->findAtomContaining(*SI);
220 MCTextAtom *TA = cast<MCTextAtom>(A);
221 if (TA->getBeginAddr() == *SI)
223 MCTextAtom *NewAtom = TA->split(*SI);
224 BBInfos[NewAtom->getBeginAddr()].Atom = NewAtom;
225 StringRef BBName = TA->getName();
226 BBName = BBName.substr(0, BBName.find_last_of(':'));
227 NewAtom->setName((BBName + ":" + utohexstr(*SI)).str());
230 // Compute succs/preds.
231 for (MCModule::atom_iterator AI = Module->atom_begin(),
232 AE = Module->atom_end();
234 MCTextAtom *TA = dyn_cast<MCTextAtom>(*AI);
236 BBInfo &CurBB = BBInfos[TA->getBeginAddr()];
237 const MCDecodedInst &LI = TA->back();
238 if (MIA.isBranch(LI.Inst)) {
240 if (MIA.evaluateBranch(LI.Inst, LI.Address, LI.Size, Target))
241 CurBB.addSucc(BBInfos[Target]);
242 if (MIA.isConditionalBranch(LI.Inst))
243 CurBB.addSucc(BBInfos[LI.Address + LI.Size]);
244 } else if (!MIA.isTerminator(LI.Inst))
245 CurBB.addSucc(BBInfos[LI.Address + LI.Size]);
249 // Create functions and basic blocks.
250 for (AddressSetTy::const_iterator CI = Calls.begin(), CE = Calls.end();
252 BBInfo &BBI = BBInfos[*CI];
253 if (!BBI.Atom) continue;
255 MCFunction &MCFN = *Module->createFunction(BBI.Atom->getName());
258 SmallSetVector<BBInfo*, 16> Worklist;
259 Worklist.insert(&BBI);
260 for (size_t wi = 0; wi < Worklist.size(); ++wi) {
261 BBInfo *BBI = Worklist[wi];
264 BBI->BB = &MCFN.createBlock(*BBI->Atom);
265 // Add all predecessors and successors to the worklist.
266 for (BBInfoSetTy::iterator SI = BBI->Succs.begin(), SE = BBI->Succs.end();
268 Worklist.insert(*SI);
269 for (BBInfoSetTy::iterator PI = BBI->Preds.begin(), PE = BBI->Preds.end();
271 Worklist.insert(*PI);
275 for (size_t wi = 0; wi < Worklist.size(); ++wi) {
276 BBInfo *BBI = Worklist[wi];
277 MCBasicBlock *MCBB = BBI->BB;
280 for (BBInfoSetTy::iterator SI = BBI->Succs.begin(), SE = BBI->Succs.end();
283 MCBB->addSuccessor((*SI)->BB);
284 for (BBInfoSetTy::iterator PI = BBI->Preds.begin(), PE = BBI->Preds.end();
287 MCBB->addPredecessor((*PI)->BB);
292 // MachO MCObjectDisassembler implementation.
294 MCMachOObjectDisassembler::MCMachOObjectDisassembler(
295 const MachOObjectFile &MOOF, const MCDisassembler &Dis,
296 const MCInstrAnalysis &MIA, uint64_t VMAddrSlide,
297 uint64_t HeaderLoadAddress)
298 : MCObjectDisassembler(MOOF, Dis, MIA), MOOF(MOOF),
299 VMAddrSlide(VMAddrSlide), HeaderLoadAddress(HeaderLoadAddress) {
302 for (section_iterator SI = MOOF.begin_sections(), SE = MOOF.end_sections();
303 SI != SE; SI.increment(ec)) {
308 // FIXME: We should use the S_ section type instead of the name.
309 if (Name == "__mod_init_func") {
310 DEBUG(dbgs() << "Found __mod_init_func section!\n");
311 SI->getContents(ModInitContents);
312 } else if (Name == "__mod_exit_func") {
313 DEBUG(dbgs() << "Found __mod_exit_func section!\n");
314 SI->getContents(ModExitContents);
319 // FIXME: Only do the translations for addresses actually inside the object.
320 uint64_t MCMachOObjectDisassembler::getEffectiveLoadAddr(uint64_t Addr) {
321 return Addr + VMAddrSlide;
325 MCMachOObjectDisassembler::getOriginalLoadAddr(uint64_t EffectiveAddr) {
326 return EffectiveAddr - VMAddrSlide;
329 uint64_t MCMachOObjectDisassembler::getEntrypoint() {
330 uint64_t EntryFileOffset = 0;
334 uint32_t LoadCommandCount = MOOF.getHeader().NumLoadCommands;
335 MachOObjectFile::LoadCommandInfo Load = MOOF.getFirstLoadCommandInfo();
336 for (unsigned I = 0;; ++I) {
337 if (Load.C.Type == MachO::LoadCommandMain) {
339 ((const MachO::entry_point_command *)Load.Ptr)->entryoff;
343 if (I == LoadCommandCount - 1)
346 Load = MOOF.getNextLoadCommandInfo(Load);
350 // If we didn't find anything, default to the common implementation.
351 // FIXME: Maybe we could also look at LC_UNIXTHREAD and friends?
353 return MCObjectDisassembler::getEntrypoint();
355 return EntryFileOffset + HeaderLoadAddress;
358 ArrayRef<uint64_t> MCMachOObjectDisassembler::getStaticInitFunctions() {
359 // FIXME: We only handle 64bit mach-o
360 assert(MOOF.is64Bit());
362 size_t EntrySize = 8;
363 size_t EntryCount = ModInitContents.size() / EntrySize;
364 return ArrayRef<uint64_t>(
365 reinterpret_cast<const uint64_t *>(ModInitContents.data()), EntryCount);
368 ArrayRef<uint64_t> MCMachOObjectDisassembler::getStaticExitFunctions() {
369 // FIXME: We only handle 64bit mach-o
370 assert(MOOF.is64Bit());
372 size_t EntrySize = 8;
373 size_t EntryCount = ModExitContents.size() / EntrySize;
374 return ArrayRef<uint64_t>(
375 reinterpret_cast<const uint64_t *>(ModExitContents.data()), EntryCount);