1 // RUN: %clang_cc1 -fsyntax-only -verify -Wvla %s 2 struct NonPOD { 3 NonPOD(); 4 }; 5 6 struct NonPOD2 { 7 NonPOD np; 8 }; 9 10 struct POD { 11 int x; 12 int y; 13 }; 14 15 // We allow VLAs of POD types, only. 16 void vla(int N) { 17 int array1[N]; // expected-warning{{variable length arrays are a C99 feature, accepted as an extension}} 18 POD array2[N]; // expected-warning{{variable length arrays are a C99 feature, accepted as an extension}} 19 NonPOD array3[N]; // expected-error{{variable length array of non-POD element type 'NonPOD'}} 20 NonPOD2 array4[N][3]; // expected-error{{variable length array of non-POD element type 'NonPOD2'}} 21 } 22 23 /// Warn about VLAs in templates. 24 template<typename T> 25 void vla_in_template(int N, T t) { 26 int array1[N]; // expected-warning{{variable length arrays are a C99 feature, accepted as an extension}} 27 } 28 29 struct HasConstantValue { 30 static const unsigned int value = 2; 31 }; 32 33 struct HasNonConstantValue { 34 static unsigned int value; 35 }; 36 37 template<typename T> 38 void vla_in_template(T t) { 39 int array2[T::value]; // expected-warning{{variable length arrays are a C99 feature, accepted as an extension}} 40 } 41 42 template void vla_in_template<HasConstantValue>(HasConstantValue); 43 template void vla_in_template<HasNonConstantValue>(HasNonConstantValue); // expected-note{{instantiation of}} 44 45 template<typename T> struct X0 { }; 46 47 // Cannot use any variably-modified type with a template parameter or 48 // argument. 49 void inst_with_vla(int N) { 50 int array[N]; // expected-warning{{variable length arrays are a C99 feature, accepted as an extension}} 51 X0<__typeof__(array)> x0a; // expected-error{{variably modified type 'typeof (array)' (aka 'int [N]') cannot be used as a template argument}} 52 } 53 54 template<typename T> 55 struct X1 { 56 template<int (&Array)[T::value]> // expected-error{{non-type template parameter of variably modified type 'int (&)[HasNonConstantValue::value]'}} \ 57 // expected-warning{{variable length arrays are a C99 feature, accepted as an extension}} 58 struct Inner { 59 60 }; 61 }; 62 63 X1<HasConstantValue> x1a; 64 X1<HasNonConstantValue> x1b; // expected-note{{in instantiation of}} 65 66 // Template argument deduction does not allow deducing a size from a VLA. 67 template<typename T, unsigned N> 68 void accept_array(T (&array)[N]); // expected-note{{candidate template ignored: failed template argument deduction}} 69 70 void test_accept_array(int N) { 71 int array[N]; // expected-warning{{variable length arrays are a C99 feature, accepted as an extension}} 72 accept_array(array); // expected-error{{no matching function for call to 'accept_array'}} 73 } 74 75 // Variably-modified types cannot be used in local classes. 76 void local_classes(int N) { 77 struct X { 78 int size; 79 int array[N]; // expected-error{{fields must have a constant size: 'variable length array in structure' extension will never be supported}} \ 80 // expected-warning{{variable length arrays are a C99 feature, accepted as an extension}} 81 }; 82 } 83 84 namespace PR7206 { 85 void f(int x) { 86 struct edge_info { 87 float left; 88 float right; 89 }; 90 struct edge_info edgeInfo[x]; // expected-warning{{variable length arrays are a C99 feature, accepted as an extension}} 91 } 92 } 93 94 namespace rdar8020206 { 95 template<typename T> 96 void f(int i) { 97 const unsigned value = i; 98 int array[value * i]; // expected-warning 2{{variable length arrays are a C99 feature, accepted as an extension}} 99 } 100 101 template void f<int>(int); // expected-note{{instantiation of}} 102 } 103 104 namespace rdar8021385 { 105 typedef int my_int; 106 struct A { typedef int my_int; }; 107 template<typename T> 108 struct B { 109 typedef typename T::my_int my_int; 110 void f0() { 111 int M = 4; 112 my_int a[M]; // expected-warning{{variable length arrays are a C99 feature, accepted as an extension}} 113 } 114 }; 115 B<A> a; 116 } 117