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// 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 <rdar://problem/6703892>, 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}}
}
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