constant-conversion.c revision 91b6014876e9186f968f74a8975ab8fc08ef1b68 
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
7void test_6792488(void) {
8  int x = 0x3ff0000000000000U; // expected-warning {{implicit conversion from 'unsigned long' to 'int' changes value from 4607182418800017408 to 0}}
9}
10
11void 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
17void test() {
18  struct { int bit : 1; } a;
19  a.bit = 1; // shouldn't warn
20}
21
22enum Test2 { K_zero, K_one };
23enum Test2 test2(enum Test2 *t) {
24  *t = 20;
25  return 10; // shouldn't warn
26}
27
28void 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
41void 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
49void 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