a09387df9f
VLA restrictions so that one can use VLAs in templates (even accidentally), but not as part of a non-type template parameter (which would be very bad). llvm-svn: 104471
93 lines
3.1 KiB
C++
93 lines
3.1 KiB
C++
// RUN: %clang_cc1 -fsyntax-only -verify -Wvla %s
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struct NonPOD {
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NonPOD();
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};
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struct NonPOD2 {
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NonPOD np;
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};
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struct POD {
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int x;
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int y;
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};
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// We allow VLAs of POD types, only.
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void vla(int N) {
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int array1[N]; // expected-warning{{variable length arrays are a C99 feature, accepted as an extension}}
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POD array2[N]; // expected-warning{{variable length arrays are a C99 feature, accepted as an extension}}
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NonPOD array3[N]; // expected-error{{variable length array of non-POD element type 'NonPOD'}}
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NonPOD2 array4[N][3]; // expected-error{{variable length array of non-POD element type 'NonPOD2'}}
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}
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/// Warn about VLAs in templates.
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template<typename T>
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void vla_in_template(int N, T t) {
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int array1[N]; // expected-warning{{variable length arrays are a C99 feature, accepted as an extension}}
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}
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struct HasConstantValue {
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static const unsigned int value = 2;
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};
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struct HasNonConstantValue {
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static unsigned int value;
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};
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template<typename T>
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void vla_in_template(T t) {
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int array2[T::value]; // expected-warning{{variable length arrays are a C99 feature, accepted as an extension}}
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}
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template void vla_in_template<HasConstantValue>(HasConstantValue);
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template void vla_in_template<HasNonConstantValue>(HasNonConstantValue); // expected-note{{instantiation of}}
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template<typename T> struct X0 { };
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// Cannot use any variably-modified type with a template parameter or
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// argument.
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void inst_with_vla(int N) {
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int array[N]; // expected-warning{{variable length arrays are a C99 feature, accepted as an extension}}
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X0<__typeof__(array)> x0a; // expected-error{{variably modified type 'typeof (array)' (aka 'int [N]') cannot be used as a template argument}}
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}
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template<typename T>
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struct X1 {
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template<int (&Array)[T::value]> // expected-error{{non-type template parameter of variably modified type 'int (&)[HasNonConstantValue::value]'}} \
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// expected-warning{{variable length arrays are a C99 feature, accepted as an extension}}
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struct Inner {
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};
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};
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X1<HasConstantValue> x1a;
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X1<HasNonConstantValue> x1b; // expected-note{{in instantiation of}}
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// Template argument deduction does not allow deducing a size from a VLA.
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template<typename T, unsigned N>
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void accept_array(T (&array)[N]); // expected-note{{candidate template ignored: failed template argument deduction}}
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void test_accept_array(int N) {
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int array[N]; // expected-warning{{variable length arrays are a C99 feature, accepted as an extension}}
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accept_array(array); // expected-error{{no matching function for call to 'accept_array'}}
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}
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// Variably-modified types cannot be used in local classes.
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void local_classes(int N) {
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struct X {
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int size;
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int array[N]; // expected-error{{fields must have a constant size: 'variable length array in structure' extension will never be supported}} \
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// expected-warning{{variable length arrays are a C99 feature, accepted as an extension}}
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};
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}
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namespace PR7206 {
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void f(int x) {
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struct edge_info {
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float left;
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float right;
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};
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struct edge_info edgeInfo[x]; // expected-warning{{variable length arrays are a C99 feature, accepted as an extension}}
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}
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}
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