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, 4 insertions, 4 deletions

diff --git a/lib/Transforms/Utils/LowerInvoke.cpp b/lib/Transforms/Utils/LowerInvoke.cpp
index 4496b3d2fe..7039a4b7e1 100644
--- a/lib/Transforms/Utils/LowerInvoke.cpp
+++ b/lib/Transforms/Utils/LowerInvoke.cpp
@@ -124,14 +124,14 @@ bool LowerInvoke::doInitialization(Module &M) {
                                       Constant::getNullValue(PtrJBList),
                                       "llvm.sjljeh.jblist", &M);
     SetJmpFn = M.getOrInsertFunction("llvm.setjmp", Type::IntTy,
-                                     PointerType::get(JmpBufTy), NULL);
+                                     PointerType::get(JmpBufTy), (Type *)0);
     LongJmpFn = M.getOrInsertFunction("llvm.longjmp", Type::VoidTy,
                                       PointerType::get(JmpBufTy),
-                                      Type::IntTy, NULL);
+                                      Type::IntTy, (Type *)0);
   }
 
   // We need the 'write' and 'abort' functions for both models.
-  AbortFn = M.getOrInsertFunction("abort", Type::VoidTy, NULL);
+  AbortFn = M.getOrInsertFunction("abort", Type::VoidTy, (Type *)0);
 
   // Unfortunately, 'write' can end up being prototyped in several different
   // ways.  If the user defines a three (or more) operand function named 'write'
@@ -148,7 +148,7 @@ bool LowerInvoke::doInitialization(Module &M) {
       WriteFn = 0;
   } else {
     WriteFn = M.getOrInsertFunction("write", Type::VoidTy, Type::IntTy,
-                                    VoidPtrTy, Type::IntTy, NULL);
+                                    VoidPtrTy, Type::IntTy, (Type *)0);
   }
   return true;
 }