| 1 | // RUN: %clang_cc1 -fsyntax-only -verify %s |
|---|
| 2 | |
|---|
| 3 | int foo(int x) { |
|---|
| 4 | return x == x; // expected-warning {{self-comparison always evaluates to true}} |
|---|
| 5 | } |
|---|
| 6 | |
|---|
| 7 | int foo2(int x) { |
|---|
| 8 | return (x) != (((x))); // expected-warning {{self-comparison always evaluates to false}} |
|---|
| 9 | } |
|---|
| 10 | |
|---|
| 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 |
|---|
| 14 | } |
|---|
| 15 | |
|---|
| 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 |
|---|
| 19 | } |
|---|
| 20 | |
|---|
| 21 | int qux(int x) { |
|---|
| 22 | return x < x; // expected-warning {{self-comparison}} |
|---|
| 23 | } |
|---|
| 24 | |
|---|
| 25 | int qux2(int x) { |
|---|
| 26 | return x > x; // expected-warning {{self-comparison}} |
|---|
| 27 | } |
|---|
| 28 | |
|---|
| 29 | int bar(float x) { |
|---|
| 30 | return x == x; // no-warning |
|---|
| 31 | } |
|---|
| 32 | |
|---|
| 33 | int bar2(float x) { |
|---|
| 34 | return x != x; // no-warning |
|---|
| 35 | } |
|---|
| 36 | |
|---|
| 37 | #define IS_THE_ANSWER(x) (x == 42) |
|---|
| 38 | |
|---|
| 39 | int macro_comparison() { |
|---|
| 40 | return IS_THE_ANSWER(42); |
|---|
| 41 | } |
|---|
| 42 | |
|---|
| 43 | // Don't complain in unevaluated contexts. |
|---|
| 44 | int compare_sizeof(int x) { |
|---|
| 45 | return sizeof(x == x); // no-warning |
|---|
| 46 | } |
|---|
| 47 | |
|---|
| 48 | int array_comparisons() { |
|---|
| 49 | int array1[2]; |
|---|
| 50 | int array2[2]; |
|---|
| 51 | |
|---|
| 52 | // |
|---|
| 53 | // compare same array |
|---|
| 54 | // |
|---|
| 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}} |
|---|
| 61 | |
|---|
| 62 | // |
|---|
| 63 | // compare different arrays |
|---|
| 64 | // |
|---|
| 65 | return array1 == array2; // expected-warning{{array comparison always evaluates to false}} |
|---|
| 66 | return array1 != array2; // expected-warning{{array comparison always evaluates to true}} |
|---|
| 67 | |
|---|
| 68 | // |
|---|
| 69 | // we don't know what these are going to be |
|---|
| 70 | // |
|---|
| 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}} |
|---|
| 75 | |
|---|
| 76 | } |
|---|
| 77 | |
|---|
| 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> |
|---|
| 80 | #define R8435950_A i |
|---|
| 81 | #define R8435950_B i |
|---|
| 82 | |
|---|
| 83 | int R8435950(int i) { |
|---|
| 84 | if (R8435950_A == R8435950_B) // no-warning |
|---|
| 85 | return 0; |
|---|
| 86 | return 1; |
|---|
| 87 | } |
|---|
| 88 | |
|---|
| 89 | __attribute__((weak)) int weak_1[3]; |
|---|
| 90 | __attribute__((weak)) int weak_2[3]; |
|---|
| 91 | _Bool compare_weak() { |
|---|
| 92 | return weak_1 == weak_2; |
|---|
| 93 | } |
|---|
| 94 | |
|---|