1 //===-- lib/MC/MCObjectSymbolizer.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/MCObjectSymbolizer.h"
11 #include "llvm/ADT/SmallString.h"
12 #include "llvm/MC/MCContext.h"
13 #include "llvm/MC/MCExpr.h"
14 #include "llvm/MC/MCInst.h"
15 #include "llvm/MC/MCRelocationInfo.h"
16 #include "llvm/MC/MCSymbol.h"
17 #include "llvm/Object/MachO.h"
18 #include "llvm/Object/ELF.h"
19 #include "llvm/Support/raw_ostream.h"
23 using namespace object;
25 //===- MCMachObjectSymbolizer ---------------------------------------------===//
28 class MCMachObjectSymbolizer : public MCObjectSymbolizer {
30 MCMachObjectSymbolizer(MCContext &Ctx, OwningPtr<MCRelocationInfo> &RelInfo,
31 const object::MachOObjectFile *MachOOF)
32 : MCObjectSymbolizer(Ctx, RelInfo, MachOOF)
35 void tryAddingPcLoadReferenceComment(raw_ostream &cStream,
36 int64_t Value, uint64_t Address) {
37 AddrToRelocMap::iterator RI = AddrToReloc.find(Address);
38 if (RI != AddrToReloc.end()) {
39 const MCExpr *RelExpr = RelInfo->createExprForRelocation(RI->second);
40 if (!RelExpr || RelExpr->EvaluateAsAbsolute(Value) == false)
43 uint64_t Addr = Value;
44 SortedSectionList::const_iterator SI = findSectionContaining(Addr);
45 errs() << " looking for sec " << Addr << "\n";
46 if (SI != SortedSections.end()) {
47 const SectionRef &S = *SI;
48 StringRef Name; S.getName(Name);
49 uint64_t SAddr; S.getAddress(SAddr);
50 if (Name == "__cstring") {
52 S.getContents(Contents);
53 Contents = Contents.substr(Addr - SAddr);
54 cStream << " ## literal pool for: "
55 << Contents.substr(0, Contents.find_first_of(0));
60 } // End unnamed namespace
62 //===- MCObjectSymbolizer -------------------------------------------------===//
64 MCObjectSymbolizer::MCObjectSymbolizer(MCContext &Ctx,
65 OwningPtr<MCRelocationInfo> &RelInfo,
66 const ObjectFile *Obj)
67 : MCSymbolizer(Ctx, RelInfo), Obj(Obj), SortedSections(), AddrToReloc() {
69 for (section_iterator SI = Obj->begin_sections(),
70 SE = Obj->end_sections();
75 section_iterator RelSecI = SI->getRelocatedSection();
76 if (RelSecI == Obj->end_sections())
79 uint64_t StartAddr; RelSecI->getAddress(StartAddr);
80 uint64_t Size; RelSecI->getSize(Size);
81 bool RequiredForExec; RelSecI->isRequiredForExecution(RequiredForExec);
82 if (RequiredForExec == false || Size == 0)
85 for (relocation_iterator RI = SI->begin_relocations(),
86 RE = SI->end_relocations();
90 // FIXME: libObject is inconsistent regarding error handling. The
91 // overwhelming majority of methods always return object_error::success,
92 // and assert for simple errors.. Here, ELFObjectFile::getRelocationOffset
93 // asserts when the file type isn't ET_REL.
94 // This workaround handles x86-64 elf, the only one that has a relocinfo.
97 const ELF64LEObjectFile *ELFObj = dyn_cast<ELF64LEObjectFile>(Obj);
100 if (ELFObj->getElfHeader()->e_type == ELF::ET_REL) {
101 RI->getOffset(Offset);
104 RI->getAddress(Offset);
107 RI->getOffset(Offset);
110 // At a specific address, only keep the first relocation.
111 if (AddrToReloc.find(Offset) == AddrToReloc.end())
112 AddrToReloc[Offset] = *RI;
117 bool MCObjectSymbolizer::
118 tryAddingSymbolicOperand(MCInst &MI, raw_ostream &cStream,
119 int64_t Value, uint64_t Address, bool IsBranch,
120 uint64_t Offset, uint64_t InstSize) {
121 AddrToRelocMap::iterator RI = AddrToReloc.find(Address + Offset);
122 if (RI != AddrToReloc.end()) {
123 if (const MCExpr *RelExpr = RelInfo->createExprForRelocation(RI->second)) {
124 MI.addOperand(MCOperand::CreateExpr(RelExpr));
127 // Only try to create a symbol+offset expression if there is no relocation.
131 // Interpret Value as a branch target.
132 if (IsBranch == false)
134 uint64_t UValue = Value;
135 // FIXME: map instead of looping each time?
137 for (symbol_iterator SI = Obj->begin_symbols(),
138 SE = Obj->end_symbols();
142 uint64_t SymAddr; SI->getAddress(SymAddr);
143 uint64_t SymSize; SI->getSize(SymSize);
144 StringRef SymName; SI->getName(SymName);
145 SymbolRef::Type SymType; SI->getType(SymType);
146 if (SymAddr == UnknownAddressOrSize || SymSize == UnknownAddressOrSize
147 || SymName.empty() || SymType != SymbolRef::ST_Function)
150 if ( SymAddr == UValue ||
151 (SymAddr <= UValue && SymAddr + SymSize > UValue)) {
152 MCSymbol *Sym = Ctx.GetOrCreateSymbol(SymName);
153 const MCExpr *Expr = MCSymbolRefExpr::Create(Sym, Ctx);
154 if (SymAddr != UValue) {
155 const MCExpr *Off = MCConstantExpr::Create(UValue - SymAddr, Ctx);
156 Expr = MCBinaryExpr::CreateAdd(Expr, Off, Ctx);
158 MI.addOperand(MCOperand::CreateExpr(Expr));
165 void MCObjectSymbolizer::
166 tryAddingPcLoadReferenceComment(raw_ostream &cStream,
167 int64_t Value, uint64_t Address) {
171 MCObjectSymbolizer::createObjectSymbolizer(MCContext &Ctx,
172 OwningPtr<MCRelocationInfo> &RelInfo,
173 const ObjectFile *Obj) {
174 if (const MachOObjectFile *MachOOF = dyn_cast<MachOObjectFile>(Obj)) {
175 return new MCMachObjectSymbolizer(Ctx, RelInfo, MachOOF);
177 return new MCObjectSymbolizer(Ctx, RelInfo, Obj);
180 // SortedSections implementation.
182 static bool SectionStartsBefore(const SectionRef &S, uint64_t Addr) {
183 uint64_t SAddr; S.getAddress(SAddr);
187 MCObjectSymbolizer::SortedSectionList::const_iterator
188 MCObjectSymbolizer::findSectionContaining(uint64_t Addr) const {
189 SortedSectionList::const_iterator
190 EndIt = SortedSections.end(),
191 It = std::lower_bound(SortedSections.begin(), EndIt,
192 Addr, SectionStartsBefore);
195 uint64_t SAddr; It->getAddress(SAddr);
196 uint64_t SSize; It->getSize(SSize);
197 if (Addr >= SAddr + SSize)
202 void MCObjectSymbolizer::insertSection(SectionRef Sec) {
203 uint64_t SAddr; Sec.getAddress(SAddr);
204 uint64_t SSize; Sec.getSize(SSize);
205 SortedSectionList::iterator It = std::lower_bound(SortedSections.begin(),
206 SortedSections.end(),
208 SectionStartsBefore);
209 if (It != SortedSections.end()) {
210 uint64_t FoundSAddr; It->getAddress(FoundSAddr);
211 if (FoundSAddr < SAddr + SSize)
212 llvm_unreachable("Inserting overlapping sections");
214 SortedSections.insert(It, Sec);