Add test cases for false positives on -Wnull-arithmetic from Richard

Trieu, and fix them by checking for array and function types as well as
pointer types.

I've added a predicate method on Type to bundle together the logic we're
using here: isPointerLikeType(). I'd welcome better names for this
predicate, this is the best I came up with. It's implemented as a switch
to be a touch lighter weight than all the chained isa<...> casts that
would result otherwise.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@133383 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 11 insertions, 0 deletions

diff --git a/test/SemaCXX/null_in_arithmetic_ops.cpp b/test/SemaCXX/null_in_arithmetic_ops.cpp
index b0303177c2..78c76e7e4c 100644
--- a/test/SemaCXX/null_in_arithmetic_ops.cpp
+++ b/test/SemaCXX/null_in_arithmetic_ops.cpp
@@ -59,6 +59,10 @@ void f() {
   b = 0 == a;
   b = 0 == &a;
 
+  b = NULL < NULL || NULL > NULL;
+  b = NULL <= NULL || NULL >= NULL;
+  b = NULL == NULL || NULL != NULL;
+
   b = ((NULL)) != a;  // expected-warning{{use of NULL in arithmetic operation}}
 
   void (^c)();
@@ -67,4 +71,11 @@ void f() {
   class X;
   void (X::*d) ();
   b = d == NULL || NULL == d || d != NULL || NULL != d;
+
+  extern void e();
+  b = e == NULL || NULL == e || e != NULL || NULL != e;
+
+  int f[2];
+  b = f == NULL || NULL == f || f != NULL || NULL != f;
+  b = "f" == NULL || NULL == "f" || "f" != NULL || NULL != "f";
 }