1 // RUN: %clang_cc1 -fsyntax-only -verify -Wtautological-overlap-compare %s 2 3 #define mydefine 2 4 5 enum Choices { 6 CHOICE_0 = 0, 7 CHOICE_1 = 1 8 }; 9 10 enum Unchoices { 11 UNCHOICE_0 = 0, 12 UNCHOICE_1 = 1 13 }; 14 15 void f(int x) { 16 int y = 0; 17 18 // > || < 19 if (x > 2 || x < 1) { } 20 if (x > 2 || x < 2) { } 21 if (x != 2 || x != 3) { } // expected-warning {{overlapping comparisons always evaluate to true}} 22 if (x > 2 || x < 3) { } // expected-warning {{overlapping comparisons always evaluate to true}} 23 if (x > 0 || x < 0) { } 24 25 if (x > 2 || x <= 1) { } 26 if (x > 2 || x <= 2) { } // expected-warning {{overlapping comparisons always evaluate to true}} 27 if (x > 2 || x <= 3) { } // expected-warning {{overlapping comparisons always evaluate to true}} 28 29 if (x >= 2 || x < 1) { } 30 if (x >= 2 || x < 2) { } // expected-warning {{overlapping comparisons always evaluate to true}} 31 if (x >= 2 || x < 3) { } // expected-warning {{overlapping comparisons always evaluate to true}} 32 33 if (x >= 2 || x <= 1) { } // expected-warning {{overlapping comparisons always evaluate to true}} 34 if (x >= 2 || x <= 2) { } // expected-warning {{overlapping comparisons always evaluate to true}} 35 if (x >= 2 || x <= 3) { } // expected-warning {{overlapping comparisons always evaluate to true}} 36 if (x >= 0 || x <= 0) { } // expected-warning {{overlapping comparisons always evaluate to true}} 37 38 // > && < 39 if (x > 2 && x < 1) { } // expected-warning {{overlapping comparisons always evaluate to false}} 40 if (x > 2 && x < 2) { } // expected-warning {{overlapping comparisons always evaluate to false}} 41 if (x > 2 && x < 3) { } // expected-warning {{overlapping comparisons always evaluate to false}} 42 if (x > 0 && x < 1) { } // expected-warning {{overlapping comparisons always evaluate to false}} 43 44 if (x > 2 && x <= 1) { } // expected-warning {{overlapping comparisons always evaluate to false}} 45 if (x > 2 && x <= 2) { } // expected-warning {{overlapping comparisons always evaluate to false}} 46 if (x > 2 && x <= 3) { } 47 48 if (x >= 2 && x < 1) { } // expected-warning {{overlapping comparisons always evaluate to false}} 49 if (x >= 2 && x < 2) { } // expected-warning {{overlapping comparisons always evaluate to false}} 50 if (x >= 2 && x < 3) { } 51 if (x >= 0 && x < 0) { } // expected-warning {{overlapping comparisons always evaluate to false}} 52 53 if (x >= 2 && x <= 1) { } // expected-warning {{overlapping comparisons always evaluate to false}} 54 if (x >= 2 && x <= 2) { } 55 if (x >= 2 && x <= 3) { } 56 57 // !=, ==, .. 58 if (x != 2 || x != 3) { } // expected-warning {{overlapping comparisons always evaluate to true}} 59 if (x != 2 || x < 3) { } // expected-warning {{overlapping comparisons always evaluate to true}} 60 if (x == 2 && x == 3) { } // expected-warning {{overlapping comparisons always evaluate to false}} 61 if (x == 2 && x > 3) { } // expected-warning {{overlapping comparisons always evaluate to false}} 62 if (x == 3 && x < 0) { } // expected-warning {{overlapping comparisons always evaluate to false}} 63 if (3 == x && x < 0) { } // expected-warning {{overlapping comparisons always evaluate to false}} 64 65 if (x == mydefine && x > 3) { } 66 if (x == (mydefine + 1) && x > 3) { } 67 68 if (x != CHOICE_0 || x != CHOICE_1) { } // expected-warning {{overlapping comparisons always evaluate to true}} 69 if (x == CHOICE_0 && x == CHOICE_1) { } // expected-warning {{overlapping comparisons always evaluate to false}} 70 71 // Don't warn if comparing x to different types 72 if (x == CHOICE_0 && x == 1) { } 73 if (x != CHOICE_0 || x != 1) { } 74 75 // "Different types" includes different enums 76 if (x == CHOICE_0 && x == UNCHOICE_1) { } 77 if (x != CHOICE_0 || x != UNCHOICE_1) { } 78 } 79 80 void enums(enum Choices c) { 81 if (c != CHOICE_0 || c != CHOICE_1) { } // expected-warning {{overlapping comparisons always evaluate to true}} 82 if (c == CHOICE_0 && c == CHOICE_1) { } // expected-warning {{overlapping comparisons always evaluate to false}} 83 84 // Don't warn if comparing x to different types 85 if (c == CHOICE_0 && c == 1) { } 86 if (c != CHOICE_0 || c != 1) { } 87 88 // "Different types" includes different enums 89 if (c == CHOICE_0 && c == UNCHOICE_1) { } 90 if (c != CHOICE_0 || c != UNCHOICE_1) { } 91 } 92 93 // Don't generate a warning here. 94 void array_out_of_bounds() { 95 int x; 96 int buffer[4]; 97 x = (-7 > 0) ? (buffer[-7]) : 0; 98 } 99
