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Diffstat (limited to 'lib/MC/MCObjectSymbolizer.cpp')
| -rw-r--r-- | lib/MC/MCObjectSymbolizer.cpp | 175 |
1 files changed, 175 insertions, 0 deletions
diff --git a/lib/MC/MCObjectSymbolizer.cpp b/lib/MC/MCObjectSymbolizer.cpp new file mode 100644 index 0000000000..e1d504ec8e --- /dev/null +++ b/lib/MC/MCObjectSymbolizer.cpp @@ -0,0 +1,175 @@ +//===-- lib/MC/MCObjectSymbolizer.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/MCObjectSymbolizer.h" +#include "llvm/ADT/SmallString.h" +#include "llvm/MC/MCContext.h" +#include "llvm/MC/MCExpr.h" +#include "llvm/MC/MCInst.h" +#include "llvm/MC/MCRelocationInfo.h" +#include "llvm/MC/MCSymbol.h" +#include "llvm/Object/MachO.h" +#include "llvm/Object/ELF.h" +#include "llvm/Support/raw_ostream.h" + +using namespace llvm; +using namespace object; + +//===- MCMachObjectSymbolizer ---------------------------------------------===// + +namespace { +class MCMachObjectSymbolizer : public MCObjectSymbolizer { +public: + MCMachObjectSymbolizer(MCContext &Ctx, OwningPtr<MCRelocationInfo> &RelInfo, + const object::MachOObjectFile *MachOOF) + : MCObjectSymbolizer(Ctx, RelInfo, MachOOF) + {} + + void tryAddingPcLoadReferenceComment(raw_ostream &cStream, + int64_t Value, uint64_t Address) { + AddrToRelocMap::iterator RI = AddrToReloc.find(Address); + if (RI != AddrToReloc.end()) { + const MCExpr *RelExpr = RelInfo->createExprForRelocation(RI->second); + if (!RelExpr || RelExpr->EvaluateAsAbsolute(Value) == false) + return; + } + uint64_t Addr = Value; + AddrToSectionMap::const_iterator SI = AddrToSection.find(Addr); + if (SI.valid()) { + DataRefImpl DRI; DRI.p = *SI; + SectionRef S(DRI, Obj); + StringRef Name; S.getName(Name); + if (Name == "__cstring") { + StringRef Contents; + S.getContents(Contents); + Contents = Contents.substr(Addr - SI.start()); + cStream << " ## literal pool for: " + << Contents.substr(0, Contents.find_first_of(0)); + } + } + } +}; +} // End unnamed namespace + +//===- MCObjectSymbolizer -------------------------------------------------===// + +MCObjectSymbolizer::MCObjectSymbolizer(MCContext &Ctx, + OwningPtr<MCRelocationInfo> &RelInfo, + const ObjectFile *Obj) + : MCSymbolizer(Ctx, RelInfo), Obj(Obj), + AddrToSectionAllocator(), AddrToSection(AddrToSectionAllocator), + AddrToReloc() { + error_code ec; + for (section_iterator SI = Obj->begin_sections(), + SE = Obj->end_sections(); + SI != SE; + SI.increment(ec)) { + if (ec) break; + uint64_t StartAddr; SI->getAddress(StartAddr); + uint64_t Size; SI->getSize(Size); + StringRef SecName; SI->getName(SecName); + bool RequiredForExec; SI->isRequiredForExecution(RequiredForExec); + if (RequiredForExec == false || Size == 0) + continue; + AddrToSection.insert(StartAddr, StartAddr + Size - 1, + SI->getRawDataRefImpl().p); + for (relocation_iterator RI = SI->begin_relocations(), + RE = SI->end_relocations(); + RI != RE; + RI.increment(ec)) { + if (ec) break; + // FIXME: libObject is inconsistent regarding error handling. The + // overwhelming majority of methods always return object_error::success, + // and assert for simple errors.. Here, ELFObjectFile::getRelocationOffset + // asserts when the file type isn't ET_REL. + // This workaround handles x86-64 elf, the only one that has a relocinfo. + uint64_t Offset; + if (Obj->isELF()) { + const ELF64LEObjectFile *ELFObj = dyn_cast<ELF64LEObjectFile>(Obj); + if (ELFObj == 0) + break; + if (ELFObj->getElfHeader()->e_type == ELF::ET_REL) { + RI->getOffset(Offset); + Offset += StartAddr; + } else { + RI->getAddress(Offset); + } + } else { + RI->getOffset(Offset); + Offset += StartAddr; + } + // At a specific address, only keep the first relocation. + if (AddrToReloc.find(Offset) == AddrToReloc.end()) + AddrToReloc[Offset] = *RI; + } + } +} + +bool MCObjectSymbolizer:: +tryAddingSymbolicOperand(MCInst &MI, raw_ostream &cStream, + int64_t Value, uint64_t Address, bool IsBranch, + uint64_t Offset, uint64_t InstSize) { + AddrToRelocMap::iterator RI = AddrToReloc.find(Address + Offset); + if (RI != AddrToReloc.end()) { + if (const MCExpr *RelExpr = RelInfo->createExprForRelocation(RI->second)) { + MI.addOperand(MCOperand::CreateExpr(RelExpr)); + return true; + } + // Only try to create a symbol+offset expression if there is no relocation. + return false; + } + + // Interpret Value as a branch target. + if (IsBranch == false) + return false; + uint64_t UValue = Value; + // FIXME: map instead of looping each time? + error_code ec; + for (symbol_iterator SI = Obj->begin_symbols(), + SE = Obj->end_symbols(); + SI != SE; + SI.increment(ec)) { + if (ec) break; + uint64_t SymAddr; SI->getAddress(SymAddr); + uint64_t SymSize; SI->getSize(SymSize); + StringRef SymName; SI->getName(SymName); + SymbolRef::Type SymType; SI->getType(SymType); + if (SymAddr == UnknownAddressOrSize || SymSize == UnknownAddressOrSize + || SymName.empty() || SymType != SymbolRef::ST_Function) + continue; + + if ( SymAddr == UValue || + (SymAddr <= UValue && SymAddr + SymSize > UValue)) { + MCSymbol *Sym = Ctx.GetOrCreateSymbol(SymName); + const MCExpr *Expr = MCSymbolRefExpr::Create(Sym, Ctx); + if (SymAddr != UValue) { + const MCExpr *Off = MCConstantExpr::Create(UValue - SymAddr, Ctx); + Expr = MCBinaryExpr::CreateAdd(Expr, Off, Ctx); + } + MI.addOperand(MCOperand::CreateExpr(Expr)); + return true; + } + } + return false; +} + +void MCObjectSymbolizer:: +tryAddingPcLoadReferenceComment(raw_ostream &cStream, + int64_t Value, uint64_t Address) { +} + +MCObjectSymbolizer * +MCObjectSymbolizer::createObjectSymbolizer(MCContext &Ctx, + OwningPtr<MCRelocationInfo> &RelInfo, + const ObjectFile *Obj) { + if (const MachOObjectFile *MachOOF = dyn_cast<MachOObjectFile>(Obj)) { + return new MCMachObjectSymbolizer(Ctx, RelInfo, MachOOF); + } + return new MCObjectSymbolizer(Ctx, RelInfo, Obj); +} |