Add a new warning when a NULL constant is used in arithmetic operations. The warning will fire on cases such as:

int x = 1 + NULL;



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@133196 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 70 insertions, 0 deletions

diff --git a/test/SemaCXX/null_in_arithmetic_ops.cpp b/test/SemaCXX/null_in_arithmetic_ops.cpp
new file mode 100644
index 0000000000..547c936c3e
--- /dev/null
+++ b/test/SemaCXX/null_in_arithmetic_ops.cpp
@@ -0,0 +1,70 @@
+// RUN: %clang_cc1 -fsyntax-only -fblocks -verify %s
+#include <stddef.h>
+
+void f() {
+  int a;
+  bool b;
+
+  a = 0 ? NULL + a : a + NULL; // expected-warning 2{{use of NULL in arithmetic operation}}
+  a = 0 ? NULL - a : a - NULL; // expected-warning 2{{use of NULL in arithmetic operation}}
+  a = 0 ? NULL / a : a / NULL; // expected-warning 2{{use of NULL in arithmetic operation}} \
+                               // expected-warning {{division by zero is undefined}}
+  a = 0 ? NULL * a : a * NULL; // expected-warning 2{{use of NULL in arithmetic operation}}
+  a = 0 ? NULL >> a : a >> NULL; // expected-warning 2{{use of NULL in arithmetic operation}}
+  a = 0 ? NULL << a : a << NULL; // expected-warning 2{{use of NULL in arithmetic operation}}
+  a = 0 ? NULL % a : a % NULL; // expected-warning 2{{use of NULL in arithmetic operation}} \
+                                  expected-warning {{remainder by zero is undefined}}
+  a = 0 ? NULL & a : a & NULL; // expected-warning 2{{use of NULL in arithmetic operation}}
+  a = 0 ? NULL | a : a | NULL; // expected-warning 2{{use of NULL in arithmetic operation}}
+  a = 0 ? NULL ^ a : a ^ NULL; // expected-warning 2{{use of NULL in arithmetic operation}}
+
+  // Using two NULLs should only give one error instead of two.
+  a = NULL + NULL; // expected-warning{{use of NULL in arithmetic operation}}
+  a = NULL - NULL; // expected-warning{{use of NULL in arithmetic operation}}
+  a = NULL / NULL; // expected-warning{{use of NULL in arithmetic operation}} \
+                   // expected-warning{{division by zero is undefined}}
+  a = NULL * NULL; // expected-warning{{use of NULL in arithmetic operation}}
+  a = NULL >> NULL; // expected-warning{{use of NULL in arithmetic operation}}
+  a = NULL << NULL; // expected-warning{{use of NULL in arithmetic operation}}
+  a = NULL % NULL; // expected-warning{{use of NULL in arithmetic operation}} \
+                   // expected-warning{{remainder by zero is undefined}}
+  a = NULL & NULL; // expected-warning{{use of NULL in arithmetic operation}}
+  a = NULL | NULL; // expected-warning{{use of NULL in arithmetic operation}}
+  a = NULL ^ NULL; // expected-warning{{use of NULL in arithmetic operation}}
+
+  a += NULL; // expected-warning{{use of NULL in arithmetic operation}}
+  a -= NULL; // expected-warning{{use of NULL in arithmetic operation}}
+  a /= NULL; // expected-warning{{use of NULL in arithmetic operation}} \
+             // expected-warning{{division by zero is undefined}}
+  a *= NULL; // expected-warning{{use of NULL in arithmetic operation}}
+  a >>= NULL; // expected-warning{{use of NULL in arithmetic operation}}
+  a <<= NULL; // expected-warning{{use of NULL in arithmetic operation}}
+  a %= NULL; // expected-warning{{use of NULL in arithmetic operation}} \
+             // expected-warning{{remainder by zero is undefined}}
+  a &= NULL; // expected-warning{{use of NULL in arithmetic operation}}
+  a |= NULL; // expected-warning{{use of NULL in arithmetic operation}}
+  a ^= NULL; // expected-warning{{use of NULL in arithmetic operation}}
+
+  b = a < NULL || NULL < a; // expected-warning 2{{use of NULL in arithmetic operation}}
+  b = a > NULL || NULL > a; // expected-warning 2{{use of NULL in arithmetic operation}}
+  b = a <= NULL || NULL <= a; // expected-warning 2{{use of NULL in arithmetic operation}}
+  b = a >= NULL || NULL >= a; // expected-warning 2{{use of NULL in arithmetic operation}}
+  b = a == NULL || NULL == a; // expected-warning 2{{use of NULL in arithmetic operation}}
+  b = a != NULL || NULL != a; // expected-warning 2{{use of NULL in arithmetic operation}}
+
+  b = &a < NULL || NULL < &a || &a > NULL || NULL > &a;
+  b = &a <= NULL || NULL <= &a || &a >= NULL || NULL >= &a;
+  b = &a == NULL || NULL == &a || &a != NULL || NULL != &a;
+
+  b = 0 == a;
+  b = 0 == &a;
+
+  b = ((NULL)) != a;  // expected-warning{{use of NULL in arithmetic operation}}
+
+  void (^c)();
+  b = c == NULL || NULL == c || c != NULL || NULL != c;
+
+  class X;
+  void (X::*d) ();
+  b = d == NULL || NULL == d || d != NULL || NULL != d;
+}