114 lines · c
1// RUN: %clang_cc1 -std=c23 -verify %s2 3/* WG14 N3006: Yes4 * Underspecified object declarations5 */6 7void struct_test(void) {8 struct S1 { int x, y; }; // expected-note {{field 'x' has type 'int' here}}9 10 auto normal_struct = (struct S1){ 1, 2 };11 auto normal_struct2 = (struct S1) { .x = 1, .y = 2 };12 auto underspecified_struct = (struct S2 { int x, y; }){ 1, 2 };13 auto underspecified_struct_redef = (struct S1 { char x, y; }){ 'A', 'B'}; // expected-error {{type 'struct S1' has incompatible definitions}} \14 expected-error {{cannot use 'auto' with array in C}} \15 expected-note {{field 'x' has type 'char' here}}16 auto underspecified_empty_struct = (struct S3 { }){ };17 auto zero_init_struct = (struct S4 { int x; }){ 0 };18 int field_struct = (struct S5 { int y; }){ 0 }.y;19}20 21void union_test(void) {22 union U1 { int a; double b; }; // expected-note {{field 'a' has type 'int' here}}23 24 auto normal_union_int = (union U1){ .a = 12 };25 auto normal_union_double = (union U1){ .b = 2.4 };26 auto underspecified_union = (union U2 { int a; double b; }){ .a = 34 };27 auto underspecified_union_redef = (union U1 { char a; double b; }){ .a = 'A' }; // expected-error {{type 'union U1' has incompatible definitions}} \28 expected-error {{cannot use 'auto' with array in C}} \29 expected-note {{field 'a' has type 'char' here}}30 auto underspecified_empty_union = (union U3 { }){ };31}32 33void enum_test(void) {34 enum E1 { FOO, BAR }; // expected-note {{enumerator 'BAR' with value 1 here}}35 36 auto normal_enum_foo = (enum E1){ FOO };37 auto normal_enum_bar = (enum E1){ BAR };38 auto underspecified_enum = (enum E2 { BAZ, QUX }){ BAZ };39 auto underspecified_enum_redef = (enum E1 { ONE, TWO }){ ONE }; // expected-error {{type 'enum E1' has incompatible definitions}} \40 expected-error {{cannot use 'auto' with array in C}} \41 expected-note {{enumerator 'ONE' with value 0 here}}42 auto underspecified_empty_enum = (enum E3 { }){ }; // expected-error {{use of empty enum}}43 auto underspecified_undeclared_enum = (enum E4){ FOO }; // expected-error {{variable has incomplete type 'enum E4'}} \44 expected-note {{forward declaration of 'enum E4'}}45}46 47void constexpr_test(void) {48 constexpr auto ce_struct = (struct S1){ 1, 2 }; // expected-error {{variable has incomplete type 'struct S1'}} \49 expected-note {{forward declaration of 'struct S1'}}50 constexpr auto ce_struct_zero_init = (struct S2 { int x; }){ 0 };51 constexpr int ce_struct_field = (struct S3 { int y; }){ 0 }.y;52 constexpr auto ce_union = (union U1){ .a = 12 }; // expected-error {{variable has incomplete type 'union U1'}} \53 expected-note {{forward declaration of 'union U1'}}54 55 constexpr auto ce_enum = (enum E1 { BAZ, QUX }){ BAZ };56 constexpr auto ce_empty_enum = (enum E2){ FOO }; // expected-error {{use of undeclared identifier 'FOO'}}57}58 59void self_reference_test(void) {60 constexpr int i = i; // expected-error {{constexpr variable 'i' must be initialized by a constant expression}} \61 expected-note {{read of object outside its lifetime is not allowed in a constant expression}}62 auto j = j; // expected-error {{variable 'j' declared with deduced type 'auto' cannot appear in its own initializer}}63}64 65void redefinition_test(void) {66 const struct S { int x; } s; // expected-warning {{default initialization of an object of type 'const struct S' leaves the object uninitialized}} \67 expected-note {{previous definition is here}}68 constexpr struct S s = {0}; // expected-error {{redefinition of 's'}}69}70 71void declaring_an_underspecified_defied_object_test(void) {72 struct S { int x, y; };73 constexpr int i = (struct T { int a, b; }){0, 1}.a;74 75 struct T t = { 1, 2 };76}77 78void constexpr_complience_test(void) {79 int x = (struct Foo { int x; }){ 0 }.x;80 constexpr int y = (struct Bar { int x; }){ 0 }.x;81}82 83void builtin_functions_test(void) {84 constexpr typeof(struct s *) x = 0;85 auto so = sizeof(struct S {});86 auto to = (typeof(struct S {})){};87}88 89void misc_test(void) {90 constexpr struct S { int a, b; } y = { 0 };91 constexpr int a = 0, b = 0;92 auto c = (struct T { int x, y; }){0, 0};93 auto s2 = ({struct T { int x; } s = {}; s.x; });94 auto s3 = ((struct {}){},0); // expected-warning {{left operand of comma operator has no effect}}95 constexpr int (*fp)(struct X { int x; } val) = 0;96 auto v = (void (*)(int y))0;97}98 99void misc_struct_test(void) {100 constexpr struct {101 int a;102 } a = {};103 104 constexpr struct {105 int b;106 } b = (struct S { int x; }){ 0 }; // expected-error-re {{initializing 'const struct (unnamed struct at {{.*}}n3006.c:104:13)' with an expression of incompatible type 'struct S'}}107 108 auto z = ({109 int a = 12;110 struct {} s;111 a;112 });113}114