1 // RUN: %clang_cc1 -fsyntax-only -verify %s
4 return x == x; // expected-warning {{self-comparison always evaluates to true}}
8 return (x) != (((x))); // expected-warning {{self-comparison always evaluates to false}}
11 void foo3(short s, short t) {
12 if (s == s) {} // expected-warning {{self-comparison always evaluates to true}}
13 if (s == t) {} // no-warning
16 void foo4(void* v, void* w) {
17 if (v == v) {} // expected-warning {{self-comparison always evaluates to true}}
18 if (v == w) {} // no-warning
22 return x < x; // expected-warning {{self-comparison}}
26 return x > x; // expected-warning {{self-comparison}}
30 return x == x; // no-warning
34 return x != x; // no-warning
37 #define IS_THE_ANSWER(x) (x == 42)
39 int macro_comparison() {
40 return IS_THE_ANSWER(42);
43 // Don't complain in unevaluated contexts.
44 int compare_sizeof(int x) {
45 return sizeof(x == x); // no-warning
48 int array_comparisons() {
55 return array1 == array1; // expected-warning{{self-comparison always evaluates to true}}
56 return array1 != array1; // expected-warning{{self-comparison always evaluates to false}}
57 return array1 < array1; // expected-warning{{self-comparison always evaluates to false}}
58 return array1 <= array1; // expected-warning{{self-comparison always evaluates to true}}
59 return array1 > array1; // expected-warning{{self-comparison always evaluates to false}}
60 return array1 >= array1; // expected-warning{{self-comparison always evaluates to true}}
63 // compare different arrays
65 return array1 == array2; // expected-warning{{array comparison always evaluates to false}}
66 return array1 != array2; // expected-warning{{array comparison always evaluates to true}}
69 // we don't know what these are going to be
71 return array1 < array2; // expected-warning{{array comparison always evaluates to a constant}}
72 return array1 <= array2; // expected-warning{{array comparison always evaluates to a constant}}
73 return array1 > array2; // expected-warning{{array comparison always evaluates to a constant}}
74 return array1 >= array2; // expected-warning{{array comparison always evaluates to a constant}}
78 // Don't issue a warning when either the left or right side of the comparison
79 // results from a macro expansion. <rdar://problem/8435950>
84 if (R8435950_A == R8435950_B) // no-warning
89 __attribute__((weak)) int weak_1[3];
90 __attribute__((weak)) int weak_2[3];
91 _Bool compare_weak() {
92 return weak_1 == weak_2;