fix AsmPrinter::GetBlockAddressSymbol to always return a unique
label instead of trying to form one based on the BB name (which
causes collisions if the name is empty).  This fixes PR6608


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98495 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/MachineModuleInfo.cpp b/lib/CodeGen/MachineModuleInfo.cpp
index fdbda8f..a23cc1a 100644
--- a/lib/CodeGen/MachineModuleInfo.cpp
+++ b/lib/CodeGen/MachineModuleInfo.cpp
@@ -104,6 +104,18 @@
       UsedFunctions.insert(F);
 }
 
+/// getAddrLabelSymbol - Return the symbol to be used for the specified basic
+/// block when its address is taken.  This cannot be its normal LBB label
+/// because the block may be accessed outside its containing function.
+MCSymbol *MachineModuleInfo::getAddrLabelSymbol(const BasicBlock *BB) {
+  assert(BB->hasAddressTaken() &&
+         "Shouldn't get label for block without address taken");
+  MCSymbol *&Entry = AddrLabelSymbols[const_cast<BasicBlock*>(BB)];
+  if (Entry) return Entry;
+  return Entry = Context.CreateTempSymbol();
+}
+
+
 //===-EH-------------------------------------------------------------------===//
 
 /// getOrCreateLandingPadInfo - Find or create an LandingPadInfo for the