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.

llvm-svn: 23888

1 files changed, 2 insertions, 1 deletions

diff --git a/llvm/lib/Debugger/UnixLocalInferiorProcess.cpp b/llvm/lib/Debugger/UnixLocalInferiorProcess.cpp
index 1731beaa039..6758e2de9d4 100644
--- a/llvm/lib/Debugger/UnixLocalInferiorProcess.cpp
+++ b/llvm/lib/Debugger/UnixLocalInferiorProcess.cpp
@@ -924,7 +924,8 @@ static void runChild(Module *M, const std::vector<std::string> &Arguments,
 
   // If the program didn't explicitly call exit, call exit now, for the program.
   // This ensures that any atexit handlers get called correctly.
-  Function *Exit = M->getOrInsertFunction("exit", Type::VoidTy, Type::IntTy, 0);
+  Function *Exit = M->getOrInsertFunction("exit", Type::VoidTy, Type::IntTy,
+                                          (Type *)0);
 
   std::vector<GenericValue> Args;
   GenericValue ResultGV;