// RUN: %clang_cc1 -fsyntax-only -verify %s int foo(int x) { return x == x; // expected-warning {{self-comparison always evaluates to true}} } int foo2(int x) { return (x) != (((x))); // expected-warning {{self-comparison always evaluates to false}} } void foo3(short s, short t) { if (s == s) {} // expected-warning {{self-comparison always evaluates to true}} if (s == t) {} // no-warning } void foo4(void* v, void* w) { if (v == v) {} // expected-warning {{self-comparison always evaluates to true}} if (v == w) {} // no-warning } int qux(int x) { return x < x; // expected-warning {{self-comparison}} } int qux2(int x) { return x > x; // expected-warning {{self-comparison}} } int bar(float x) { return x == x; // no-warning } int bar2(float x) { return x != x; // no-warning } // Motivated by , self-comparisons of enum constants // should not be warned about. These can be expanded from macros, and thus // are usually deliberate. int compare_enum() { enum { A }; return A == A; // no-warning } // Don't complain in unevaluated contexts. int compare_sizeof(int x) { return sizeof(x == x); // no-warning } int array_comparisons() { int array1[2]; int array2[2]; // // compare same array // return array1 == array1; // expected-warning{{self-comparison always evaluates to true}} return array1 != array1; // expected-warning{{self-comparison always evaluates to false}} return array1 < array1; // expected-warning{{self-comparison always evaluates to false}} return array1 <= array1; // expected-warning{{self-comparison always evaluates to true}} return array1 > array1; // expected-warning{{self-comparison always evaluates to false}} return array1 >= array1; // expected-warning{{self-comparison always evaluates to true}} // // compare differrent arrays // return array1 == array2; // expected-warning{{array comparison always evaluates to false}} return array1 != array2; // expected-warning{{array comparison always evaluates to true}} // // we don't know what these are going to be // return array1 < array2; // expected-warning{{array comparison always evaluates to a constant}} return array1 <= array2; // expected-warning{{array comparison always evaluates to a constant}} return array1 > array2; // expected-warning{{array comparison always evaluates to a constant}} return array1 >= array2; // expected-warning{{array comparison always evaluates to a constant}} }