a0d266d705
According to [[dcl.type.elab] p2](http://eel.is/c++draft/dcl.type.elab#2): > If an [elaborated-type-specifier](http://eel.is/c++draft/dcl.type.elab#nt:elaborated-type-specifier) is the sole constituent of a declaration, the declaration is ill-formed unless it is an explicit specialization, an explicit instantiation or it has one of the following forms [...] Consider the following: ```cpp template<typename T> struct A { template<typename U> struct B; }; template<> template<typename U> struct A<int>::B; // #1 ``` The _elaborated-type-specifier_ at `#1` declares an explicit specialization (which is itself a template). We currently (incorrectly) reject this, and this PR fixes that. I moved the point at which _elaborated-type-specifiers_ with _nested-name-specifiers_ are diagnosed from `ParsedFreeStandingDeclSpec` to `ActOnTag` for two reasons: `ActOnTag` isn't called for explicit instantiations and partial/explicit specializations, and because it's where we determine if a member specialization is being declared. With respect to diagnostics, I am currently issuing the diagnostic without marking the declaration as invalid or returning early, which results in more diagnostics that I think is necessary. I would like feedback regarding what the "correct" behavior should be here.
58 lines
1.1 KiB
C++
58 lines
1.1 KiB
C++
// RUN: %clang_cc1 -fsyntax-only -verify %s
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// PR5061
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namespace a {
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template <typename T> class C {};
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}
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namespace b {
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template<typename T> void f0(a::C<T> &a0) { }
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}
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namespace test1 {
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int a = 0;
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template <class T> class Base { };
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template <class T> class Derived : public Base<T> {
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int foo() {
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return test1::a;
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}
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};
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}
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namespace test2 {
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class Impl {
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public:
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int foo();
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};
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template <class T> class Magic : public Impl {
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int foo() {
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return Impl::foo();
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}
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};
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}
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namespace PR6063 {
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template <typename T> void f(T, T);
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namespace detail
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{
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using PR6063::f;
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}
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template <typename T>
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void g(T a, T b)
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{
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detail::f(a, b);
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}
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}
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namespace PR12291 {
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template <typename T>
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class Outer2 {
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template <typename V>
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template <typename W>
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class Outer2<V>::Inner; // expected-error{{nested name specifier 'Outer2<V>::' for declaration does not refer into a class, class template or class template partial specialization}}
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// expected-error@-1{{forward declaration of class cannot have a nested name specifier}}
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};
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}
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