1 // RUN: %clang_cc1 -std=c11 -fsyntax-only -Wno-strict-prototypes -Wno-implicit-function-declaration -verify %s
2 // RUN: %clang_cc1 -std=c99 -pedantic -fsyntax-only -Wno-strict-prototypes -Wno-implicit-function-declaration -verify=expected,ext %s
3
4 void g(void);
5
foo(int n)6 void foo(int n) {
7 (void) _Generic(0, // ext-warning {{'_Generic' is a C11 extension}}
8 struct A: 0, // expected-error {{type 'struct A' in generic association incomplete}}
9 void(): 0, // expected-error {{type 'void ()' in generic association not an object type}}
10 int[n]: 0); // expected-error {{type 'int[n]' in generic association is a variably modified type}}
11
12 (void) _Generic(0, // ext-warning {{'_Generic' is a C11 extension}}
13 void (*)(): 0, // expected-note {{compatible type 'void (*)()' specified here}}
14 void (*)(void): 0); // expected-error {{type 'void (*)(void)' in generic association compatible with previously specified type 'void (*)()'}}
15
16 (void) _Generic((void (*)()) 0, // expected-error {{controlling expression type 'void (*)()' compatible with 2 generic association types}} \
17 // ext-warning {{'_Generic' is a C11 extension}}
18 void (*)(int): 0, // expected-note {{compatible type 'void (*)(int)' specified here}}
19 void (*)(void): 0); // expected-note {{compatible type 'void (*)(void)' specified here}}
20
21 (void) _Generic(0, // expected-error {{controlling expression type 'int' not compatible with any generic association type}} \
22 // ext-warning {{'_Generic' is a C11 extension}}
23 char: 0, short: 0, long: 0);
24
25 int a1[_Generic(0, int: 1, short: 2, float: 3, default: 4) == 1 ? 1 : -1]; // ext-warning {{'_Generic' is a C11 extension}}
26 int a2[_Generic(0, default: 1, short: 2, float: 3, int: 4) == 4 ? 1 : -1]; // ext-warning {{'_Generic' is a C11 extension}}
27 int a3[_Generic(0L, int: 1, short: 2, float: 3, default: 4) == 4 ? 1 : -1]; // ext-warning {{'_Generic' is a C11 extension}}
28 int a4[_Generic(0L, default: 1, short: 2, float: 3, int: 4) == 1 ? 1 : -1]; // ext-warning {{'_Generic' is a C11 extension}}
29 int a5[_Generic(0, int: 1, short: 2, float: 3) == 1 ? 1 : -1]; // ext-warning {{'_Generic' is a C11 extension}}
30 int a6[_Generic(0, short: 1, float: 2, int: 3) == 3 ? 1 : -1]; // ext-warning {{'_Generic' is a C11 extension}}
31
32 int a7[_Generic("test", char *: 1, default: 2) == 1 ? 1 : -1]; // ext-warning {{'_Generic' is a C11 extension}}
33 int a8[_Generic(g, void (*)(void): 1, default: 2) == 1 ? 1 : -1]; // ext-warning {{'_Generic' is a C11 extension}}
34
35 const int i = 12;
36 int a9[_Generic(i, int: 1, default: 2) == 1 ? 1 : -1]; // ext-warning {{'_Generic' is a C11 extension}}
37
38 // This is expected to not trigger any diagnostics because the controlling
39 // expression is not evaluated.
40 (void)_Generic(*(int *)0, int: 1); // ext-warning {{'_Generic' is a C11 extension}}
41 }
42
43 int __attribute__((overloadable)) test (int);
44 double __attribute__((overloadable)) test (double);
45 char testc(char);
46
PR30201(void)47 void PR30201(void) {
48 _Generic(4, char:testc, default:test)(4); // ext-warning {{'_Generic' is a C11 extension}}
49 }
50
GH50227(void)51 void GH50227(void) {
52 // Previously, the controlling expression for the outer _Generic makes it
53 // result dependent, and testing whether that controlling expression has side
54 // effects would cause a crash.
55 _Generic( // ext-warning {{'_Generic' is a C11 extension}}
56 n(
57 _Generic(n++, int : 0) // expected-error {{cannot increment value of type 'int ()'}} ext-warning {{'_Generic' is a C11 extension}}
58 ), int : 0);
59 }
60
61 struct Test {
62 int i;
63 };
64
unreachable_associations(const int i,const struct Test t)65 void unreachable_associations(const int i, const struct Test t) {
66 _Static_assert( // ext-warning {{'_Static_assert' is a C11 extension}}
67 _Generic(i, // ext-warning {{'_Generic' is a C11 extension}}
68 const int : 1, // expected-warning {{due to lvalue conversion of the controlling expression, association of type 'const int' will never be selected because it is qualified}}
69 volatile int : 2, // expected-warning {{due to lvalue conversion of the controlling expression, association of type 'volatile int' will never be selected because it is qualified}}
70 int[12] : 3, // expected-warning {{due to lvalue conversion of the controlling expression, association of type 'int[12]' will never be selected because it is of array type}}
71 int : 4,
72 default : 5
73 ) == 4, "we had better pick int!");
74 _Static_assert( // ext-warning {{'_Static_assert' is a C11 extension}}
75 _Generic(t, // ext-warning {{'_Generic' is a C11 extension}}
76 struct Test : 1,
77 const struct Test : 2, // expected-warning {{due to lvalue conversion of the controlling expression, association of type 'const struct Test' will never be selected because it is qualified}}
78 default : 3
79 ) == 1, "we had better pick struct Test, not const struct Test!"); // C-specific result
80 }
81
GH55562(void)82 void GH55562(void) {
83 // Ensure that you can still define a type within a generic selection
84 // association (despite it not being particularly useful).
85 (void)_Generic(1, struct S { int a; } : 0, default : 0); // ext-warning {{'_Generic' is a C11 extension}}
86 struct S s = { 0 };
87 int i = s.a;
88 }
89