1 files changed, 96 insertions, 0 deletions
diff --git a/test/SemaObjC/objc-literal-comparison.m b/test/SemaObjC/objc-literal-comparison.m
new file mode 100644
index 0000000000000..f1aa8ecd91e22
--- /dev/null
+++ b/test/SemaObjC/objc-literal-comparison.m
@@ -0,0 +1,96 @@
+// RUN: %clang_cc1 -fsyntax-only -Wno-everything -Wobjc-literal-compare "-Dnil=((id)0)" -verify %s
+// RUN: %clang_cc1 -fsyntax-only -Wno-everything -Wobjc-literal-compare "-Dnil=(id)0" -verify %s
+// RUN: %clang_cc1 -fsyntax-only -Wno-everything -Wobjc-literal-compare "-Dnil=0" -verify %s
+
+// (test the warning flag as well)
+
+typedef signed char BOOL;
+
+@interface BaseObject
++ (instancetype)new;
+@end
+
+@interface NSObject : BaseObject
+- (BOOL)isEqual:(id)other;
+@end
+
+@interface NSNumber : NSObject
++ (NSNumber *)numberWithInt:(int)value;
++ (NSNumber *)numberWithDouble:(double)value;
++ (NSNumber *)numberWithBool:(BOOL)value;
+@end
+
+@interface NSArray : NSObject
++ (id)arrayWithObjects:(const id [])objects count:(unsigned long)cnt;
+@end
+
+@interface NSDictionary : NSObject
++ (id)dictionaryWithObjects:(const id [])objects forKeys:(const id [])keys count:(unsigned long)cnt;
+@end
+
+@interface NSString : NSObject
+@end
+
+void testComparisonsWithFixits(id obj) {
+  if (obj == @"") return; // expected-warning{{direct comparison of a string literal has undefined behavior}} expected-note{{use 'isEqual:' instead}}
+  if (obj != @"") return; // expected-warning{{direct comparison of a string literal has undefined behavior}} expected-note{{use 'isEqual:' instead}}
+  if (@"" == obj) return; // expected-warning{{direct comparison of a string literal has undefined behavior}} expected-note{{use 'isEqual:' instead}}
+  if (@"" == @"") return; // expected-warning{{direct comparison of a string literal has undefined behavior}} expected-note{{use 'isEqual:' instead}}
+
+  if (@[] == obj) return; // expected-warning{{direct comparison of an array literal has undefined behavior}} expected-note{{use 'isEqual:' instead}}
+  if (@{} == obj) return; // expected-warning{{direct comparison of a dictionary literal has undefined behavior}} expected-note{{use 'isEqual:' instead}}
+  if (@12 == obj) return; // expected-warning{{direct comparison of a numeric literal has undefined behavior}} expected-note{{use 'isEqual:' instead}}
+  if (@1.0 == obj) return; // expected-warning{{direct comparison of a numeric literal has undefined behavior}} expected-note{{use 'isEqual:' instead}}
+  if (@__objc_yes == obj) return; // expected-warning{{direct comparison of a numeric literal has undefined behavior}} expected-note{{use 'isEqual:' instead}}
+  if (@(1+1) == obj) return; // expected-warning{{direct comparison of a boxed expression has undefined behavior}} expected-note{{use 'isEqual:' instead}}
+}
+
+
+@interface BadEqualReturnString : NSString
+- (void)isEqual:(id)other;
+@end
+
+@interface BadEqualArgString : NSString
+- (BOOL)isEqual:(int)other;
+@end
+
+
+void testComparisonsWithoutFixits() {
+  if ([BaseObject new] == @"") return; // expected-warning{{direct comparison of a string literal has undefined behavior}}
+
+  if ([BadEqualReturnString new] == @"") return; // expected-warning{{direct comparison of a string literal has undefined behavior}}
+  if ([BadEqualArgString new] == @"") return; // expected-warning{{direct comparison of a string literal has undefined behavior}}
+
+  if (@"" < @"") return; // expected-warning{{direct comparison of a string literal has undefined behavior}}
+  if (@"" > @"") return; // expected-warning{{direct comparison of a string literal has undefined behavior}}
+  if (@"" <= @"") return; // expected-warning{{direct comparison of a string literal has undefined behavior}}
+  if (@"" >= @"") return; // expected-warning{{direct comparison of a string literal has undefined behavior}}
+}
+
+
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wobjc-string-compare"
+
+void testWarningFlags(id obj) {
+  if (obj == @"") return; // no-warning
+  if (@"" == obj) return; // no-warning
+
+  if (obj == @1) return; // expected-warning{{direct comparison of a numeric literal has undefined behavior}} expected-note{{use 'isEqual:' instead}}
+  if (@1 == obj) return; // expected-warning{{direct comparison of a numeric literal has undefined behavior}} expected-note{{use 'isEqual:' instead}}
+}
+
+#pragma clang diagnostic pop
+
+
+void testNilComparison() {
+  // Don't warn when comparing to nil in a macro.
+#define RETURN_IF_NIL(x) if (x == nil || nil == x) return
+  RETURN_IF_NIL(@"");
+  RETURN_IF_NIL(@1);
+  RETURN_IF_NIL(@1.0);
+  RETURN_IF_NIL(@[]);
+  RETURN_IF_NIL(@{});
+  RETURN_IF_NIL(@__objc_yes);
+  RETURN_IF_NIL(@(1+1));
+}
+