Fix a memory leak in MachOObjectFile.

MachOObjectFile owns a MachOObj, but never frees it. Both MachOObjectFile
and MachOObj want to own the MemoryBuffer, though, so we have to be careful
and give them each one of their own.

Thanks to Greg Clayton, Eric Christopher and Michael Spencer for helping
figure out what's going wrong here.

rdar://12561773

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168923 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 17 insertions, 10 deletions

diff --git a/include/llvm/Object/MachO.h b/include/llvm/Object/MachO.h
index 4e03daab16..50c577dc26 100644
--- a/include/llvm/Object/MachO.h
+++ b/include/llvm/Object/MachO.h
@@ -44,7 +44,7 @@ public:
   virtual unsigned getArch() const;
   virtual StringRef getLoadName() const;
 
-  MachOObject *getObject() { return MachOObj; }
+  MachOObject *getObject() { return MachOObj.get(); }
 
   static inline bool classof(const Binary *v) {
     return v->isMachO();
@@ -104,7 +104,7 @@ protected:
   virtual error_code getLibraryPath(DataRefImpl LibData, StringRef &Res) const;
 
 private:
-  MachOObject *MachOObj;
+  OwningPtr<MachOObject> MachOObj;
   mutable uint32_t RegisteredStringTable;
   typedef SmallVector<DataRefImpl, 1> SectionList;
   SectionList Sections;
diff --git a/lib/Object/MachOObjectFile.cpp b/lib/Object/MachOObjectFile.cpp
index 45aeaac6b8..bcea3bb5e9 100644
--- a/lib/Object/MachOObjectFile.cpp
+++ b/lib/Object/MachOObjectFile.cpp
@@ -50,7 +50,14 @@ ObjectFile *ObjectFile::createMachOObjectFile(MemoryBuffer *Buffer) {
   MachOObject *MachOObj = MachOObject::LoadFromBuffer(Buffer, &Err);
   if (!MachOObj)
     return NULL;
-  return new MachOObjectFile(Buffer, MachOObj, ec);
+  // MachOObject takes ownership of the Buffer we passed to it, and
+  // MachOObjectFile does, too, so we need to make sure they don't get the
+  // same object. A MemoryBuffer is cheap (it's just a reference to memory,
+  // not a copy of the memory itself), so just make a new copy here for
+  // the MachOObjectFile.
+  MemoryBuffer *NewBuffer =
+    MemoryBuffer::getMemBuffer(Buffer->getBuffer(), "", false);
+  return new MachOObjectFile(NewBuffer, MachOObj, ec);
 }
 
 /*===-- Symbols -----------------------------------------------------------===*/
@@ -474,7 +481,7 @@ error_code MachOObjectFile::getSectionName(DataRefImpl DRI,
                                            StringRef &Result) const {
   // FIXME: thread safety.
   static char result[34];
-  if (is64BitLoadCommand(MachOObj, DRI)) {
+  if (is64BitLoadCommand(MachOObj.get(), DRI)) {
     InMemoryStruct<macho::Segment64LoadCommand> SLC;
     LoadCommandInfo LCI = MachOObj->getLoadCommandInfo(DRI.d.a);
     MachOObj->ReadSegment64LoadCommand(LCI, SLC);
@@ -501,7 +508,7 @@ error_code MachOObjectFile::getSectionName(DataRefImpl DRI,
 
 error_code MachOObjectFile::getSectionAddress(DataRefImpl DRI,
                                               uint64_t &Result) const {
-  if (is64BitLoadCommand(MachOObj, DRI)) {
+  if (is64BitLoadCommand(MachOObj.get(), DRI)) {
     InMemoryStruct<macho::Section64> Sect;
     getSection64(DRI, Sect);
     Result = Sect->Address;
@@ -515,7 +522,7 @@ error_code MachOObjectFile::getSectionAddress(DataRefImpl DRI,
 
 error_code MachOObjectFile::getSectionSize(DataRefImpl DRI,
                                            uint64_t &Result) const {
-  if (is64BitLoadCommand(MachOObj, DRI)) {
+  if (is64BitLoadCommand(MachOObj.get(), DRI)) {
     InMemoryStruct<macho::Section64> Sect;
     getSection64(DRI, Sect);
     Result = Sect->Size;
@@ -529,7 +536,7 @@ error_code MachOObjectFile::getSectionSize(DataRefImpl DRI,
 
 error_code MachOObjectFile::getSectionContents(DataRefImpl DRI,
                                                StringRef &Result) const {
-  if (is64BitLoadCommand(MachOObj, DRI)) {
+  if (is64BitLoadCommand(MachOObj.get(), DRI)) {
     InMemoryStruct<macho::Section64> Sect;
     getSection64(DRI, Sect);
     Result = MachOObj->getData(Sect->Offset, Sect->Size);
@@ -543,7 +550,7 @@ error_code MachOObjectFile::getSectionContents(DataRefImpl DRI,
 
 error_code MachOObjectFile::getSectionAlignment(DataRefImpl DRI,
                                                 uint64_t &Result) const {
-  if (is64BitLoadCommand(MachOObj, DRI)) {
+  if (is64BitLoadCommand(MachOObj.get(), DRI)) {
     InMemoryStruct<macho::Section64> Sect;
     getSection64(DRI, Sect);
     Result = uint64_t(1) << Sect->Align;
@@ -557,7 +564,7 @@ error_code MachOObjectFile::getSectionAlignment(DataRefImpl DRI,
 
 error_code MachOObjectFile::isSectionText(DataRefImpl DRI,
                                           bool &Result) const {
-  if (is64BitLoadCommand(MachOObj, DRI)) {
+  if (is64BitLoadCommand(MachOObj.get(), DRI)) {
     InMemoryStruct<macho::Section64> Sect;
     getSection64(DRI, Sect);
     Result = !strcmp(Sect->Name, "__text");
@@ -664,7 +671,7 @@ relocation_iterator MachOObjectFile::getSectionRelBegin(DataRefImpl Sec) const {
 }
 relocation_iterator MachOObjectFile::getSectionRelEnd(DataRefImpl Sec) const {
   uint32_t last_reloc;
-  if (is64BitLoadCommand(MachOObj, Sec)) {
+  if (is64BitLoadCommand(MachOObj.get(), Sec)) {
     InMemoryStruct<macho::Section64> Sect;
     getSection64(Sec, Sect);
     last_reloc = Sect->NumRelocationTableEntries;