When a function takes a variable number of pointer arguments, with a zero

pointer marking the end of the list, the zero *must* be cast to the pointer
type.  An un-cast zero is a 32-bit int, and at least on x86_64, gcc will
not extend the zero to 64 bits, thus allowing the upper 32 bits to be
random junk.

The new END_WITH_NULL macro may be used to annotate a such a function
so that GCC (version 4 or newer) will detect the use of un-casted zero
at compile time.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23888 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Transforms/Utils/LowerAllocations.cpp

@@ -83,7 +83,7 @@ bool LowerAllocations::doInitialization(Module &M) {
     MallocFunc = M.getOrInsertFunction("malloc", FT);
   }
   if (FreeFunc == 0)
-    FreeFunc = M.getOrInsertFunction("free"  , Type::VoidTy, SBPTy, 0);
+    FreeFunc = M.getOrInsertFunction("free"  , Type::VoidTy, SBPTy, (Type *)0);
 
   return true;
 }