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-rw-r--r--lib/MC/MCObjectSymbolizer.cpp296
1 files changed, 196 insertions, 100 deletions
diff --git a/lib/MC/MCObjectSymbolizer.cpp b/lib/MC/MCObjectSymbolizer.cpp
index aa7648e..b9131d1 100644
--- a/lib/MC/MCObjectSymbolizer.cpp
+++ b/lib/MC/MCObjectSymbolizer.cpp
@@ -15,7 +15,7 @@
#include "llvm/MC/MCRelocationInfo.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/Object/MachO.h"
-#include "llvm/Object/ELF.h"
+#include "llvm/Object/ELFObjectFile.h"
#include "llvm/Support/raw_ostream.h"
#include <algorithm>
@@ -26,100 +26,127 @@ using namespace object;
namespace {
class MCMachObjectSymbolizer : public MCObjectSymbolizer {
+ const MachOObjectFile *MOOF;
+ // __TEXT;__stubs support.
+ uint64_t StubsStart;
+ uint64_t StubsCount;
+ uint64_t StubSize;
+ uint64_t StubsIndSymIndex;
+
public:
MCMachObjectSymbolizer(MCContext &Ctx, OwningPtr<MCRelocationInfo> &RelInfo,
- const object::MachOObjectFile *MachOOF)
- : MCObjectSymbolizer(Ctx, RelInfo, MachOOF)
- {}
+ const MachOObjectFile *MOOF);
+
+ StringRef findExternalFunctionAt(uint64_t Addr) LLVM_OVERRIDE;
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;
- SortedSectionList::const_iterator SI = findSectionContaining(Addr);
- if (SI != SortedSections.end()) {
- const SectionRef &S = *SI;
- StringRef Name; S.getName(Name);
- uint64_t SAddr; S.getAddress(SAddr);
- if (Name == "__cstring") {
- StringRef Contents;
- S.getContents(Contents);
- Contents = Contents.substr(Addr - SAddr);
- cStream << " ## literal pool for: "
- << Contents.substr(0, Contents.find_first_of(0));
- }
- }
- }
+ int64_t Value,
+ uint64_t Address) LLVM_OVERRIDE;
};
} // End unnamed namespace
-//===- MCObjectSymbolizer -------------------------------------------------===//
-MCObjectSymbolizer::MCObjectSymbolizer(MCContext &Ctx,
- OwningPtr<MCRelocationInfo> &RelInfo,
- const ObjectFile *Obj)
- : MCSymbolizer(Ctx, RelInfo), Obj(Obj), SortedSections(), AddrToReloc() {
+MCMachObjectSymbolizer::
+MCMachObjectSymbolizer(MCContext &Ctx, OwningPtr<MCRelocationInfo> &RelInfo,
+ const MachOObjectFile *MOOF)
+ : MCObjectSymbolizer(Ctx, RelInfo, MOOF), MOOF(MOOF),
+ StubsStart(0), StubsCount(0), StubSize(0), StubsIndSymIndex(0) {
+
error_code ec;
- for (section_iterator SI = Obj->begin_sections(),
- SE = Obj->end_sections();
- SI != SE;
- SI.increment(ec)) {
+ for (section_iterator SI = MOOF->begin_sections(), SE = MOOF->end_sections();
+ SI != SE; SI.increment(ec)) {
if (ec) break;
-
- section_iterator RelSecI = SI->getRelocatedSection();
- if (RelSecI == Obj->end_sections())
- continue;
-
- uint64_t StartAddr; RelSecI->getAddress(StartAddr);
- uint64_t Size; RelSecI->getSize(Size);
- bool RequiredForExec; RelSecI->isRequiredForExecution(RequiredForExec);
- if (RequiredForExec == false || Size == 0)
- continue;
- insertSection(*SI);
- 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);
- }
+ StringRef Name; SI->getName(Name);
+ if (Name == "__stubs") {
+ SectionRef StubsSec = *SI;
+ if (MOOF->is64Bit()) {
+ MachO::section_64 S = MOOF->getSection64(StubsSec.getRawDataRefImpl());
+ StubsIndSymIndex = S.reserved1;
+ StubSize = S.reserved2;
} else {
- RI->getOffset(Offset);
- Offset += StartAddr;
+ MachO::section S = MOOF->getSection(StubsSec.getRawDataRefImpl());
+ StubsIndSymIndex = S.reserved1;
+ StubSize = S.reserved2;
}
- // At a specific address, only keep the first relocation.
- if (AddrToReloc.find(Offset) == AddrToReloc.end())
- AddrToReloc[Offset] = *RI;
+ assert(StubSize && "Mach-O stub entry size can't be zero!");
+ StubsSec.getAddress(StubsStart);
+ StubsSec.getSize(StubsCount);
+ StubsCount /= StubSize;
+ }
+ }
+}
+
+StringRef MCMachObjectSymbolizer::findExternalFunctionAt(uint64_t Addr) {
+ // FIXME: also, this can all be done at the very beginning, by iterating over
+ // all stubs and creating the calls to outside functions. Is it worth it
+ // though?
+ if (!StubSize)
+ return StringRef();
+ uint64_t StubIdx = (Addr - StubsStart) / StubSize;
+ if (StubIdx >= StubsCount)
+ return StringRef();
+
+ uint32_t SymtabIdx =
+ MOOF->getIndirectSymbolTableEntry(MOOF->getDysymtabLoadCommand(), StubIdx);
+
+ StringRef SymName;
+ symbol_iterator SI = MOOF->begin_symbols();
+ error_code ec;
+ for (uint32_t i = 0; i != SymtabIdx; ++i) {
+ SI.increment(ec);
+ }
+ SI->getName(SymName);
+ assert(SI != MOOF->end_symbols() && "Stub wasn't found in the symbol table!");
+ assert(SymName.front() == '_' && "Mach-O symbol doesn't start with '_'!");
+ return SymName.substr(1);
+}
+
+void MCMachObjectSymbolizer::
+tryAddingPcLoadReferenceComment(raw_ostream &cStream, int64_t Value,
+ uint64_t Address) {
+ if (const RelocationRef *R = findRelocationAt(Address)) {
+ const MCExpr *RelExpr = RelInfo->createExprForRelocation(*R);
+ if (!RelExpr || RelExpr->EvaluateAsAbsolute(Value) == false)
+ return;
+ }
+ uint64_t Addr = Value;
+ if (const SectionRef *S = findSectionContaining(Addr)) {
+ StringRef Name; S->getName(Name);
+ uint64_t SAddr; S->getAddress(SAddr);
+ if (Name == "__cstring") {
+ StringRef Contents;
+ S->getContents(Contents);
+ Contents = Contents.substr(Addr - SAddr);
+ cStream << " ## literal pool for: "
+ << Contents.substr(0, Contents.find_first_of(0));
}
}
}
+//===- MCObjectSymbolizer -------------------------------------------------===//
+
+MCObjectSymbolizer::MCObjectSymbolizer(MCContext &Ctx,
+ OwningPtr<MCRelocationInfo> &RelInfo,
+ const ObjectFile *Obj)
+ : MCSymbolizer(Ctx, RelInfo), Obj(Obj), SortedSections(), AddrToReloc() {
+}
+
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)) {
+ if (IsBranch) {
+ StringRef ExtFnName = findExternalFunctionAt((uint64_t)Value);
+ if (!ExtFnName.empty()) {
+ MCSymbol *Sym = Ctx.GetOrCreateSymbol(ExtFnName);
+ const MCExpr *Expr = MCSymbolRefExpr::Create(Sym, Ctx);
+ MI.addOperand(MCOperand::CreateExpr(Expr));
+ return true;
+ }
+ }
+
+ if (const RelocationRef *R = findRelocationAt(Address + Offset)) {
+ if (const MCExpr *RelExpr = RelInfo->createExprForRelocation(*R)) {
MI.addOperand(MCOperand::CreateExpr(RelExpr));
return true;
}
@@ -133,10 +160,8 @@ tryAddingSymbolicOperand(MCInst &MI, raw_ostream &cStream,
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)) {
+ 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);
@@ -166,13 +191,16 @@ tryAddingPcLoadReferenceComment(raw_ostream &cStream,
int64_t Value, uint64_t Address) {
}
+StringRef MCObjectSymbolizer::findExternalFunctionAt(uint64_t Addr) {
+ return StringRef();
+}
+
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);
- }
+ if (const MachOObjectFile *MOOF = dyn_cast<MachOObjectFile>(Obj))
+ return new MCMachObjectSymbolizer(Ctx, RelInfo, MOOF);
return new MCObjectSymbolizer(Ctx, RelInfo, Obj);
}
@@ -183,32 +211,100 @@ static bool SectionStartsBefore(const SectionRef &S, uint64_t Addr) {
return SAddr < Addr;
}
-MCObjectSymbolizer::SortedSectionList::const_iterator
-MCObjectSymbolizer::findSectionContaining(uint64_t Addr) const {
- SortedSectionList::const_iterator
+const SectionRef *MCObjectSymbolizer::findSectionContaining(uint64_t Addr) {
+ if (SortedSections.empty())
+ buildSectionList();
+
+ SortedSectionList::iterator
EndIt = SortedSections.end(),
It = std::lower_bound(SortedSections.begin(), EndIt,
Addr, SectionStartsBefore);
if (It == EndIt)
- return It;
+ return 0;
uint64_t SAddr; It->getAddress(SAddr);
uint64_t SSize; It->getSize(SSize);
if (Addr >= SAddr + SSize)
- return EndIt;
- return It;
+ return 0;
+ return &*It;
+}
+
+const RelocationRef *MCObjectSymbolizer::findRelocationAt(uint64_t Addr) {
+ if (AddrToReloc.empty())
+ buildRelocationByAddrMap();
+
+ AddrToRelocMap::const_iterator RI = AddrToReloc.find(Addr);
+ if (RI == AddrToReloc.end())
+ return 0;
+ return &RI->second;
+}
+
+void MCObjectSymbolizer::buildSectionList() {
+ error_code ec;
+ for (section_iterator SI = Obj->begin_sections(), SE = Obj->end_sections();
+ SI != SE; SI.increment(ec)) {
+ if (ec) break;
+
+ bool RequiredForExec; SI->isRequiredForExecution(RequiredForExec);
+ if (RequiredForExec == false)
+ continue;
+ uint64_t SAddr; SI->getAddress(SAddr);
+ uint64_t SSize; SI->getSize(SSize);
+ SortedSectionList::iterator It = std::lower_bound(SortedSections.begin(),
+ SortedSections.end(),
+ SAddr,
+ SectionStartsBefore);
+ if (It != SortedSections.end()) {
+ uint64_t FoundSAddr; It->getAddress(FoundSAddr);
+ if (FoundSAddr < SAddr + SSize)
+ llvm_unreachable("Inserting overlapping sections");
+ }
+ SortedSections.insert(It, *SI);
+ }
}
-void MCObjectSymbolizer::insertSection(SectionRef Sec) {
- uint64_t SAddr; Sec.getAddress(SAddr);
- uint64_t SSize; Sec.getSize(SSize);
- SortedSectionList::iterator It = std::lower_bound(SortedSections.begin(),
- SortedSections.end(),
- SAddr,
- SectionStartsBefore);
- if (It != SortedSections.end()) {
- uint64_t FoundSAddr; It->getAddress(FoundSAddr);
- if (FoundSAddr < SAddr + SSize)
- llvm_unreachable("Inserting overlapping sections");
+void MCObjectSymbolizer::buildRelocationByAddrMap() {
+ error_code ec;
+ for (section_iterator SI = Obj->begin_sections(), SE = Obj->end_sections();
+ SI != SE; SI.increment(ec)) {
+ if (ec) break;
+
+ section_iterator RelSecI = SI->getRelocatedSection();
+ if (RelSecI == Obj->end_sections())
+ continue;
+
+ uint64_t StartAddr; RelSecI->getAddress(StartAddr);
+ uint64_t Size; RelSecI->getSize(Size);
+ bool RequiredForExec; RelSecI->isRequiredForExecution(RequiredForExec);
+ if (RequiredForExec == false || Size == 0)
+ continue;
+ 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->getELFFile()->getHeader()->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;
+ }
}
- SortedSections.insert(It, Sec);
}
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