Merge Ctors from nested transactions.

Axel-Naumann · Axel-Naumann · commit 69568116cd7b · 2014-05-27T18:20:19.000+02:00
We cannot run nested transactions' initializations until the parent is done.
But the parent transaction must not replace the nested transactions' static initialization either.
The only way out is to collapse all transactions' static initializers until they are run.
This fixes
root [0] TTree *chain = new TTree("abc","title")
which left chain == 0 before.
diff --git a/interpreter/llvm/src/tools/clang/lib/CodeGen/CodeGenModule.cpp b/interpreter/llvm/src/tools/clang/lib/CodeGen/CodeGenModule.cpp
@@ -493,6 +493,8 @@ void CodeGenModule::AddGlobalDtor(llvm::Function * Dtor, int Priority) {
 }
 
 void CodeGenModule::EmitCtorList(CtorList &Fns, const char *GlobalName) {
+  if (Fns.empty())
+    return;
   // Ctor function type is void()*.
   llvm::FunctionType* CtorFTy = llvm::FunctionType::get(VoidTy, false);
   llvm::Type *CtorPFTy = llvm::PointerType::getUnqual(CtorFTy);
@@ -501,8 +503,23 @@ void CodeGenModule::EmitCtorList(CtorList &Fns, const char *GlobalName) {
   llvm::StructType *CtorStructTy =
     llvm::StructType::get(Int32Ty, llvm::PointerType::getUnqual(CtorFTy), NULL);
 
+
   // Construct the constructor and destructor arrays.
   SmallVector<llvm::Constant*, 8> Ctors;
+
+  // Add existing ones:
+  if (llvm::GlobalVariable* OldGlobal
+      = TheModule.getGlobalVariable(GlobalName, true)) {
+    if (const llvm::ConstantArray* CArr =
+        llvm::dyn_cast<llvm::ConstantArray>(OldGlobal->getInitializer())) {
+      uint64_t OldSize = CArr->getType()->getNumElements();
+      for (uint64_t Idx = 0; Idx < OldSize; ++Idx) {
+        Ctors.push_back(CArr->getAggregateElement(Idx));
+      }
+    }
+    OldGlobal->eraseFromParent();
+  }
+
   for (CtorList::const_iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) {
     llvm::Constant *S[] = {
       llvm::ConstantInt::get(Int32Ty, I->second, false),
