1 files changed, 120 insertions, 0 deletions
diff --git a/clang-tools-extra/test/clang-tidy/misc-redundant-expression.cpp b/clang-tools-extra/test/clang-tidy/misc-redundant-expression.cpp
new file mode 100644
index 00000000000..5efc163ae19
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/misc-redundant-expression.cpp
@@ -0,0 +1,120 @@
+// RUN: %check_clang_tidy %s misc-redundant-expression %t
+
+struct Point {
+  int x;
+  int y;
+  int a[5];
+} P;
+
+extern Point P1;
+extern Point P2;
+
+extern int foo(int x);
+extern int bar(int x);
+extern int bat(int x, int y);
+
+int Test(int X, int Y) {
+  if (X - X) return 1;
+  // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: both side of operator are equivalent [misc-redundant-expression]
+  if (X / X) return 1;
+  // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: both side of operator are equivalent
+  if (X % X) return 1;
+  // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: both side of operator are equivalent
+
+  if (X & X) return 1;
+  // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: both side of operator are equivalent
+  if (X | X) return 1;
+  // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: both side of operator are equivalent
+  if (X ^ X) return 1;
+  // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: both side of operator are equivalent
+
+  if (X < X) return 1;
+  // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: both side of operator are equivalent
+  if (X <= X) return 1;
+  // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: both side of operator are equivalent
+  if (X > X) return 1;
+  // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: both side of operator are equivalent
+  if (X >= X) return 1;
+  // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: both side of operator are equivalent
+
+  if (X && X) return 1;
+  // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: both side of operator are equivalent
+  if (X || X) return 1;
+  // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: both side of operator are equivalent
+
+  if (X != (((X)))) return 1;
+  // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: both side of operator are equivalent
+
+  if (X + 1 == X + 1) return 1;
+  // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: both side of operator are equivalent
+  if (X + 1 != X + 1) return 1;
+  // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: both side of operator are equivalent
+  if (X + 1 <= X + 1) return 1;
+  // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: both side of operator are equivalent
+  if (X + 1 >= X + 1) return 1;
+  // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: both side of operator are equivalent
+
+  if ((X != 1 || Y != 1) && (X != 1 || Y != 1)) return 1;
+  // CHECK-MESSAGES: :[[@LINE-1]]:26: warning: both side of operator are equivalent
+  if (P.a[X - P.x] != P.a[X - P.x]) return 1;
+  // CHECK-MESSAGES: :[[@LINE-1]]:20: warning: both side of operator are equivalent
+
+  if ((int)X < (int)X) return 1;
+  // CHECK-MESSAGES: :[[@LINE-1]]:14: warning: both side of operator are equivalent
+
+  if ( + "dummy" == + "dummy") return 1;
+  // CHECK-MESSAGES: :[[@LINE-1]]:18: warning: both side of operator are equivalent
+  if (L"abc" == L"abc") return 1;     
+  // CHECK-MESSAGES: :[[@LINE-1]]:14: warning: both side of operator are equivalent
+
+  if (foo(0) - 2 < foo(0) - 2) return 1;
+  // CHECK-MESSAGES: :[[@LINE-1]]:18: warning: both side of operator are equivalent  
+  if (foo(bar(0)) < (foo(bar((0))))) return 1;
+  // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: both side of operator are equivalent  
+
+  if (P1.x < P2.x && P1.x < P2.x) return 1;
+  // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: both side of operator are equivalent  
+  if (P2.a[P1.x + 2] < P2.x && P2.a[(P1.x) + (2)] < (P2.x)) return 1;
+  // CHECK-MESSAGES: :[[@LINE-1]]:29: warning: both side of operator are equivalent  
+
+  return 0;
+}
+
+int Valid(int X, int Y) {
+  if (X != Y) return 1;
+  if (X == X + 0) return 1;
+  if (P.x == P.y) return 1;
+  if (P.a[P.x] < P.a[P.y]) return 1;
+  if (P.a[0] < P.a[1]) return 1;
+
+  if (P.a[0] < P.a[0ULL]) return 1;
+  if (0 < 0ULL) return 1;
+  if ((int)0 < (int)0ULL) return 1;
+
+  if (++X != ++X) return 1;
+  if (P.a[X]++ != P.a[X]++) return 1;
+  if (P.a[X++] != P.a[X++]) return 1;
+
+  if ("abc" == "ABC") return 1;
+  if (foo(bar(0)) < (foo(bat(0, 1)))) return 1;
+  return 0;
+}
+
+#define LT(x, y) (void)((x) < (y))
+
+int TestMacro(int X, int Y) {
+  LT(0, 0);
+  LT(1, 0);
+  LT(X, X);
+  LT(X+1, X + 1);
+}
+
+int TestFalsePositive(int* A, int X, float F) {
+  // Produced by bison.
+  X = A[(2) - (2)];
+  X = A['a' - 'a'];
+
+  // Testing NaN.
+  if (F != F && F == F) return 1;
+  return 0;
+}