1 // RUN: %clang_cc1 -fsyntax-only -verify -triple x86_64-apple-darwin %s 2 3 // This file tests -Wconstant-conversion, a subcategory of -Wconversion 4 // which is on by default. 5 6 // rdar://problem/6792488 7 void test_6792488(void) { 8 int x = 0x3ff0000000000000U; // expected-warning {{implicit conversion from 'unsigned long' to 'int' changes value from 4607182418800017408 to 0}} 9 } 10 11 void test_7809123(void) { 12 struct { int i5 : 5; } a; 13 14 a.i5 = 36; // expected-warning {{implicit truncation from 'int' to bitfield changes value from 36 to 4}} 15 } 16 17 void test() { 18 struct { int bit : 1; } a; 19 a.bit = 1; // shouldn't warn 20 } 21 22 enum Test2 { K_zero, K_one }; 23 enum Test2 test2(enum Test2 *t) { 24 *t = 20; 25 return 10; // shouldn't warn 26 } 27 28 void test3() { 29 struct A { 30 unsigned int foo : 2; 31 int bar : 2; 32 }; 33 34 struct A a = { 0, 10 }; // expected-warning {{implicit truncation from 'int' to bitfield changes value from 10 to -2}} 35 struct A b[] = { 0, 10, 0, 0 }; // expected-warning {{implicit truncation from 'int' to bitfield changes value from 10 to -2}} 36 struct A c[] = {{10, 0}}; // expected-warning {{implicit truncation from 'int' to bitfield changes value from 10 to 2}} 37 struct A d = (struct A) { 10, 0 }; // expected-warning {{implicit truncation from 'int' to bitfield changes value from 10 to 2}} 38 struct A e = { .foo = 10 }; // expected-warning {{implicit truncation from 'int' to bitfield changes value from 10 to 2}} 39 } 40 41 void test4() { 42 struct A { 43 char c : 2; 44 } a; 45 46 a.c = 0x101; // expected-warning {{implicit truncation from 'int' to bitfield changes value from 257 to 1}} 47 } 48 49 void test5() { 50 struct A { 51 _Bool b : 1; 52 } a; 53 54 // Don't warn about this implicit conversion to bool, or at least 55 // don't warn about it just because it's a bitfield. 56 a.b = 100; 57 } 58 59 void test6() { 60 // Test that unreachable code doesn't trigger the truncation warning. 61 unsigned char x = 0 ? 65535 : 1; // no-warning 62 unsigned char y = 1 ? 65535 : 1; // expected-warning {{changes value}} 63 } 64 65 void test7() { 66 struct { 67 unsigned int twoBits1:2; 68 unsigned int twoBits2:2; 69 unsigned int reserved:28; 70 } f; 71 72 f.twoBits1 = ~1; // expected-warning {{implicit truncation from 'int' to bitfield changes value from -2 to 2}} 73 f.twoBits2 = ~2; // expected-warning {{implicit truncation from 'int' to bitfield changes value from -3 to 1}} 74 f.twoBits1 &= ~1; // no-warning 75 f.twoBits2 &= ~2; // no-warning 76 } 77 78 void test8() { 79 enum E { A, B, C }; 80 struct { enum E x : 1; } f; 81 f.x = C; // expected-warning {{implicit truncation from 'int' to bitfield changes value from 2 to 0}} 82 } 83 84 void test9() { 85 const char max_char = 0x7F; 86 const short max_short = 0x7FFF; 87 const int max_int = 0x7FFFFFFF; 88 89 const short max_char_plus_one = (short)max_char + 1; 90 const int max_short_plus_one = (int)max_short + 1; 91 const long max_int_plus_one = (long)max_int + 1; 92 93 char new_char = max_char_plus_one; // expected-warning {{implicit conversion from 'const short' to 'char' changes value from 128 to -128}} 94 short new_short = max_short_plus_one; // expected-warning {{implicit conversion from 'const int' to 'short' changes value from 32768 to -32768}} 95 int new_int = max_int_plus_one; // expected-warning {{implicit conversion from 'const long' to 'int' changes value from 2147483648 to -2147483648}} 96 97 char hex_char = 0x80; 98 short hex_short = 0x8000; 99 int hex_int = 0x80000000; 100 101 char oct_char = 0200; 102 short oct_short = 0100000; 103 int oct_int = 020000000000; 104 105 char bin_char = 0b10000000; 106 short bin_short = 0b1000000000000000; 107 int bin_int = 0b10000000000000000000000000000000; 108 109 #define CHAR_MACRO_HEX 0xff 110 char macro_char_hex = CHAR_MACRO_HEX; 111 #define CHAR_MACRO_DEC 255 112 char macro_char_dec = CHAR_MACRO_DEC; // expected-warning {{implicit conversion from 'int' to 'char' changes value from 255 to -1}} 113 114 char array_init[] = { 255, 127, 128, 129, 0 }; 115 } 116
