X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FMC%2FMCObjectSymbolizer.cpp;h=cdf743e6bbb21240af08ebfc7e0b4554951f4ca1;hb=bb96dfcf4f58ae7152f4be92254a0bb1c0995e6d;hp=e1d504ec8e913388d7742600cb6ad4696fa35d47;hpb=2c94d0faa0e1c268893d5e04dc77e8a35889db00;p=oota-llvm.git

diff --git a/lib/MC/MCObjectSymbolizer.cpp b/lib/MC/MCObjectSymbolizer.cpp
index e1d504ec8e9..cdf743e6bbb 100644
--- a/lib/MC/MCObjectSymbolizer.cpp
+++ b/lib/MC/MCObjectSymbolizer.cpp
@@ -14,9 +14,10 @@
 #include "llvm/MC/MCInst.h"
 #include "llvm/MC/MCRelocationInfo.h"
 #include "llvm/MC/MCSymbol.h"
+#include "llvm/Object/ELFObjectFile.h"
 #include "llvm/Object/MachO.h"
-#include "llvm/Object/ELF.h"
 #include "llvm/Support/raw_ostream.h"
+#include <algorithm>
 
 using namespace llvm;
 using namespace object;
@@ -25,99 +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;
-    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));
-      }
-    }
-  }
+                                       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),
-      AddrToSectionAllocator(), AddrToSection(AddrToSectionAllocator),
-      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;
-    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);
-        }
+    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;
     }
@@ -131,10 +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);
@@ -164,12 +191,120 @@ 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);
 }
+
+// SortedSections implementation.
+
+static bool SectionStartsBefore(const SectionRef &S, uint64_t Addr) {
+  uint64_t SAddr; S.getAddress(SAddr);
+  return SAddr < Addr;
+}
+
+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 0;
+  uint64_t SAddr; It->getAddress(SAddr);
+  uint64_t SSize; It->getSize(SSize);
+  if (Addr >= SAddr + SSize)
+    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::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;
+    }
+  }
+}