Adding support for deregistering EH frames with MCJIT.

Patch by Yaron Keren



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192753 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp
index bda32d4..49f8dc3 100644
--- a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp
+++ b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp
@@ -32,6 +32,9 @@
 void RuntimeDyldImpl::registerEHFrames() {
 }
 
+void RuntimeDyldImpl::deregisterEHFrames() {
+}
+
 // Resolve the relocations for all symbols we currently know about.
 void RuntimeDyldImpl::resolveRelocations() {
   // First, resolve relocations associated with external symbols.
@@ -595,7 +598,13 @@
 }
 
 void RuntimeDyld::registerEHFrames() {
-  return Dyld->registerEHFrames();
+  if (Dyld)
+    Dyld->registerEHFrames();
+}
+
+void RuntimeDyld::deregisterEHFrames() {
+  if (Dyld)
+    Dyld->deregisterEHFrames();
 }
 
 } // end namespace llvm
diff --git a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp
index 97e03f0..fa14c8c 100644
--- a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp
+++ b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp
@@ -160,10 +160,24 @@
     uint64_t EHFrameLoadAddr = Sections[EHFrameSID].LoadAddress;
     size_t EHFrameSize = Sections[EHFrameSID].Size;
     MemMgr->registerEHFrames(EHFrameAddr, EHFrameLoadAddr, EHFrameSize);
+    RegisteredEHFrameSections.push_back(EHFrameSID);
   }
   UnregisteredEHFrameSections.clear();
 }
 
+void RuntimeDyldELF::deregisterEHFrames() {
+  if (!MemMgr)
+    return;
+  for (int i = 0, e = RegisteredEHFrameSections.size(); i != e; ++i) {
+    SID EHFrameSID = RegisteredEHFrameSections[i];
+    uint8_t *EHFrameAddr = Sections[EHFrameSID].Address;
+    uint64_t EHFrameLoadAddr = Sections[EHFrameSID].LoadAddress;
+    size_t EHFrameSize = Sections[EHFrameSID].Size;
+    MemMgr->deregisterEHFrames(EHFrameAddr, EHFrameLoadAddr, EHFrameSize);
+  }
+  RegisteredEHFrameSections.clear();
+}
+
 ObjectImage *RuntimeDyldELF::createObjectImage(ObjectBuffer *Buffer) {
   if (Buffer->getBufferSize() < ELF::EI_NIDENT)
     llvm_unreachable("Unexpected ELF object size");
diff --git a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.h b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.h
index 058078b..3adf827 100644
--- a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.h
+++ b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.h
@@ -126,6 +126,7 @@
   // in a table until we receive a request to register all unregistered
   // EH frame sections with the memory manager.
   SmallVector<SID, 2> UnregisteredEHFrameSections;
+  SmallVector<SID, 2> RegisteredEHFrameSections;
 
 public:
   RuntimeDyldELF(RTDyldMemoryManager *mm) : RuntimeDyldImpl(mm)
@@ -141,6 +142,7 @@
   virtual bool isCompatibleFormat(const ObjectBuffer *Buffer) const;
   virtual ObjectImage *createObjectImage(ObjectBuffer *InputBuffer);
   virtual void registerEHFrames();
+  virtual void deregisterEHFrames();
   virtual void finalizeLoad(ObjSectionToIDMap &SectionMap);
   virtual ~RuntimeDyldELF();
 };
diff --git a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldImpl.h b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldImpl.h
index 2fb2813..0628fa7 100644
--- a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldImpl.h
+++ b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldImpl.h
@@ -342,6 +342,8 @@
 
   virtual void registerEHFrames();
 
+  virtual void deregisterEHFrames();
+
   virtual void finalizeLoad(ObjSectionToIDMap &SectionMap) {}
 };