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

1 files changed, 3 insertions, 1 deletions

diff --git a/include/llvm/Module.h b/include/llvm/Module.h
index d4932fc855..d491c752fd 100644
--- a/include/llvm/Module.h
+++ b/include/llvm/Module.h
@@ -22,6 +22,7 @@
 #include "llvm/Function.h"
 #include "llvm/GlobalVariable.h"
 #include "llvm/ADT/SetVector.h"
+#include "llvm/Support/DataTypes.h"
 
 namespace llvm {
 
@@ -111,7 +112,8 @@ public:
   /// table.  If it does not exist, add a prototype for the function and return
   /// it.  This version of the method takes a null terminated list of function
   /// arguments, which makes it easier for clients to use.
-  Function *getOrInsertFunction(const std::string &Name, const Type *RetTy,...);
+  Function *getOrInsertFunction(const std::string &Name, const Type *RetTy,...)
+    END_WITH_NULL;
 
   /// getFunction - Look up the specified function in the module symbol table.
   /// If it does not exist, return null.