Clean-up of memory buffer and object ownership model in MCJIT

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165053 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 35 insertions, 42 deletions

diff --git a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp
index a1c0e4020f..597c5cb131 100644
--- a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp
+++ b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp
@@ -12,16 +12,19 @@
 //===----------------------------------------------------------------------===//
 
 #define DEBUG_TYPE "dyld"
+#include "RuntimeDyldELF.h"
+#include "JITRegistrar.h"
+#include "ObjectImageCommon.h"
 #include "llvm/ADT/OwningPtr.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/IntervalMap.h"
-#include "RuntimeDyldELF.h"
 #include "llvm/Object/ObjectFile.h"
+#include "llvm/ExecutionEngine/ObjectImage.h"
+#include "llvm/ExecutionEngine/ObjectBuffer.h"
 #include "llvm/Support/ELF.h"
 #include "llvm/ADT/Triple.h"
 #include "llvm/Object/ELF.h"
-#include "JITRegistrar.h"
 using namespace llvm;
 using namespace llvm::object;
 
@@ -41,19 +44,12 @@ class DyldELFObject : public ELFObjectFile<target_endianness, is64Bits> {
   typedef typename ELFDataTypeTypedefHelper<
           target_endianness, is64Bits>::value_type addr_type;
 
-protected:
-  // This duplicates the 'Data' member in the 'Binary' base class
-  // but it is necessary to workaround a bug in gcc 4.2
-  MemoryBuffer *InputData;
-
 public:
-  DyldELFObject(MemoryBuffer *Object, error_code &ec);
+  DyldELFObject(MemoryBuffer *Wrapper, error_code &ec);
 
   void updateSectionAddress(const SectionRef &Sec, uint64_t Addr);
   void updateSymbolAddress(const SymbolRef &Sym, uint64_t Addr);
 
-  const MemoryBuffer& getBuffer() const { return *InputData; }
-
   // Methods for type inquiry through isa, cast and dyn_cast
   static inline bool classof(const Binary *v) {
     return (isa<ELFObjectFile<target_endianness, is64Bits> >(v)
@@ -69,14 +65,15 @@ public:
 };
 
 template<support::endianness target_endianness, bool is64Bits>
-class ELFObjectImage : public ObjectImage {
+class ELFObjectImage : public ObjectImageCommon {
   protected:
     DyldELFObject<target_endianness, is64Bits> *DyldObj;
     bool Registered;
 
   public:
-    ELFObjectImage(DyldELFObject<target_endianness, is64Bits> *Obj)
-    : ObjectImage(Obj),
+    ELFObjectImage(ObjectBuffer *Input,
+                   DyldELFObject<target_endianness, is64Bits> *Obj)
+    : ObjectImageCommon(Input, Obj),
       DyldObj(Obj),
       Registered(false) {}
 
@@ -99,20 +96,22 @@ class ELFObjectImage : public ObjectImage {
 
     virtual void registerWithDebugger()
     {
-      JITRegistrar::getGDBRegistrar().registerObject(DyldObj->getBuffer());
+      JITRegistrar::getGDBRegistrar().registerObject(*Buffer);
       Registered = true;
     }
     virtual void deregisterWithDebugger()
     {
-      JITRegistrar::getGDBRegistrar().deregisterObject(DyldObj->getBuffer());
+      JITRegistrar::getGDBRegistrar().deregisterObject(*Buffer);
     }
 };
 
+// The MemoryBuffer passed into this constructor is just a wrapper around the
+// actual memory.  Ultimately, the Binary parent class will take ownership of
+// this MemoryBuffer object but not the underlying memory.
 template<support::endianness target_endianness, bool is64Bits>
-DyldELFObject<target_endianness, is64Bits>::DyldELFObject(MemoryBuffer *Object,
+DyldELFObject<target_endianness, is64Bits>::DyldELFObject(MemoryBuffer *Wrapper,
                                                           error_code &ec)
-  : ELFObjectFile<target_endianness, is64Bits>(Object, ec),
-    InputData(Object) {
+  : ELFObjectFile<target_endianness, is64Bits>(Wrapper, ec) {
   this->isDyldELFObject = true;
 }
 
@@ -148,46 +147,39 @@ void DyldELFObject<target_endianness, is64Bits>::updateSymbolAddress(
 
 namespace llvm {
 
-ObjectImage *RuntimeDyldELF::createObjectImage(
-                                         const MemoryBuffer *ConstInputBuffer) {
-  MemoryBuffer *InputBuffer = const_cast<MemoryBuffer*>(ConstInputBuffer);
-  std::pair<unsigned char, unsigned char> Ident = getElfArchType(InputBuffer);
+ObjectImage *RuntimeDyldELF::createObjectImage(ObjectBuffer *Buffer) {
+  if (Buffer->getBufferSize() < ELF::EI_NIDENT)
+    llvm_unreachable("Unexpected ELF object size");
+  std::pair<unsigned char, unsigned char> Ident = std::make_pair(
+                         (uint8_t)Buffer->getBufferStart()[ELF::EI_CLASS],
+                         (uint8_t)Buffer->getBufferStart()[ELF::EI_DATA]);
   error_code ec;
 
   if (Ident.first == ELF::ELFCLASS32 && Ident.second == ELF::ELFDATA2LSB) {
     DyldELFObject<support::little, false> *Obj =
-           new DyldELFObject<support::little, false>(InputBuffer, ec);
-    return new ELFObjectImage<support::little, false>(Obj);
+           new DyldELFObject<support::little, false>(Buffer->getMemBuffer(), ec);
+    return new ELFObjectImage<support::little, false>(Buffer, Obj);
   }
   else if (Ident.first == ELF::ELFCLASS32 && Ident.second == ELF::ELFDATA2MSB) {
     DyldELFObject<support::big, false> *Obj =
-           new DyldELFObject<support::big, false>(InputBuffer, ec);
-    return new ELFObjectImage<support::big, false>(Obj);
+           new DyldELFObject<support::big, false>(Buffer->getMemBuffer(), ec);
+    return new ELFObjectImage<support::big, false>(Buffer, Obj);
   }
   else if (Ident.first == ELF::ELFCLASS64 && Ident.second == ELF::ELFDATA2MSB) {
     DyldELFObject<support::big, true> *Obj =
-           new DyldELFObject<support::big, true>(InputBuffer, ec);
-    return new ELFObjectImage<support::big, true>(Obj);
+           new DyldELFObject<support::big, true>(Buffer->getMemBuffer(), ec);
+    return new ELFObjectImage<support::big, true>(Buffer, Obj);
   }
   else if (Ident.first == ELF::ELFCLASS64 && Ident.second == ELF::ELFDATA2LSB) {
     DyldELFObject<support::little, true> *Obj =
-           new DyldELFObject<support::little, true>(InputBuffer, ec);
-    return new ELFObjectImage<support::little, true>(Obj);
+           new DyldELFObject<support::little, true>(Buffer->getMemBuffer(), ec);
+    return new ELFObjectImage<support::little, true>(Buffer, Obj);
   }
   else
     llvm_unreachable("Unexpected ELF format");
 }
 
-void RuntimeDyldELF::handleObjectLoaded(ObjectImage *Obj)
-{
-  Obj->registerWithDebugger();
-  // Save the loaded object.  It will deregister itself when deleted
-  LoadedObject = Obj;
-}
-
 RuntimeDyldELF::~RuntimeDyldELF() {
-  if (LoadedObject)
-    delete LoadedObject;
 }
 
 void RuntimeDyldELF::resolveX86_64Relocation(uint8_t *LocalAddress,
@@ -522,8 +514,9 @@ void RuntimeDyldELF::processRelocationRef(const ObjRelocationInfo &Rel,
   }
 }
 
-bool RuntimeDyldELF::isCompatibleFormat(const MemoryBuffer *InputBuffer) const {
-  StringRef Magic = InputBuffer->getBuffer().slice(0, ELF::EI_NIDENT);
-  return (memcmp(Magic.data(), ELF::ElfMagic, strlen(ELF::ElfMagic))) == 0;
+bool RuntimeDyldELF::isCompatibleFormat(const ObjectBuffer *Buffer) const {
+  if (Buffer->getBufferSize() < strlen(ELF::ElfMagic))
+    return false;
+  return (memcmp(Buffer->getBufferStart(), ELF::ElfMagic, strlen(ELF::ElfMagic))) == 0;
 }
 } // namespace llvm