Add self-comparison warnings for fields.
This expands very slightly what -Wtautological-compare considers to be
tautological to include implicit accesses to C++ fields and ObjC ivars.
I don't want to turn this into a full expression-identity check, but
these additions seem pretty well-contained, and maintain the theme
of checking for "x == x".
<rdar://problem/14431127>
llvm-svn: 190118
diff --git a/clang/test/SemaCXX/self-comparison.cpp b/clang/test/SemaCXX/self-comparison.cpp
new file mode 100644
index 0000000..fb15ec8
--- /dev/null
+++ b/clang/test/SemaCXX/self-comparison.cpp
@@ -0,0 +1,23 @@
+// RUN: %clang_cc1 -fsyntax-only -verify %s
+
+int foo(int x) {
+ return x == x; // expected-warning {{self-comparison always evaluates to true}}
+}
+
+struct X {
+ bool operator==(const X &x);
+};
+
+struct A {
+ int x;
+ X x2;
+ int a[3];
+ int b[3];
+ bool f() { return x == x; } // expected-warning {{self-comparison always evaluates to true}}
+ bool g() { return x2 == x2; } // no-warning
+ bool h() { return a == b; } // expected-warning {{array comparison always evaluates to false}}
+ bool i() {
+ int c[3];
+ return a == c; // expected-warning {{array comparison always evaluates to false}}
+ }
+};