clang/test/Sema/generic-selection.c

   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
   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
  47 void PR30201(void) {
  48   _Generic(4, char:testc, default:test)(4); // ext-warning {{'_Generic' is a C11 extension}}
  49 }
  50
  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
  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
  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 }