diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -103,6 +103,8 @@ Resolutions to C++ Defect Reports ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +- Implemented `DR2397 `_ which allows ``auto`` specifier for pointers + and reference to arrays. C Language Changes ------------------ diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td --- a/clang/include/clang/Basic/DiagnosticSemaKinds.td +++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td @@ -2314,8 +2314,6 @@ def err_binding_cannot_appear_in_own_initializer : Error< "binding %0 cannot appear in the initializer of its own " "decomposition declaration">; -def err_illegal_decl_array_of_auto : Error< - "'%0' declared as array of %1">; def err_new_array_of_auto : Error< "cannot allocate array of 'auto'">; def err_auto_not_allowed : Error< diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp --- a/clang/lib/Sema/SemaType.cpp +++ b/clang/lib/Sema/SemaType.cpp @@ -5130,17 +5130,6 @@ D.setInvalidType(true); } } - const AutoType *AT = T->getContainedAutoType(); - // Allow arrays of auto if we are a generic lambda parameter. - // i.e. [](auto (&array)[5]) { return array[0]; }; OK - if (AT && D.getContext() != DeclaratorContext::LambdaExprParameter) { - // We've already diagnosed this for decltype(auto). - if (!AT->isDecltypeAuto()) - S.Diag(DeclType.Loc, diag::err_illegal_decl_array_of_auto) - << getPrintableNameForEntity(Name) << T; - T = QualType(); - break; - } // Array parameters can be marked nullable as well, although it's not // necessary if they're marked 'static'. diff --git a/clang/test/CXX/dcl.decl/dcl.meaning/dcl.array/cwg2397.cpp b/clang/test/CXX/dcl.decl/dcl.meaning/dcl.array/cwg2397.cpp new file mode 100644 --- /dev/null +++ b/clang/test/CXX/dcl.decl/dcl.meaning/dcl.array/cwg2397.cpp @@ -0,0 +1,25 @@ +// RUN: %clang_cc1 -fsyntax-only -verify %s -std=c++11 +// RUN: %clang_cc1 -fsyntax-only -verify %s -std=c++14 + +void f() { + int a[5]; + auto (*b)[5] = &a; + auto (&c)[5] = a; + auto (&&d)[5] = static_cast(a); + auto e[] = {0}; // expected-error{{cannot deduce actual type for variable 'e' with type 'auto[]' from initializer list}} + static_assert(__is_same(decltype(b), int (*)[5]), ""); + static_assert(__is_same(decltype(c), int (&)[5]), ""); + static_assert(__is_same(decltype(d), int (&&)[5]), ""); +} + +#if __cplusplus >= 201402L + +constexpr int g() { + int a[] = {1, 2, 3}; + auto (&b)[3] = a; + return b[1]; +} + +static_assert(g() == 2, ""); + +#endif diff --git a/clang/test/CXX/dcl.decl/dcl.meaning/dcl.array/p1-cxx0x.cpp b/clang/test/CXX/dcl.decl/dcl.meaning/dcl.array/p1-cxx0x.cpp --- a/clang/test/CXX/dcl.decl/dcl.meaning/dcl.array/p1-cxx0x.cpp +++ b/clang/test/CXX/dcl.decl/dcl.meaning/dcl.array/p1-cxx0x.cpp @@ -2,6 +2,6 @@ void f() { int b[5]; - auto a[5] = b; // expected-error{{'a' declared as array of 'auto'}} - auto *c[5] = b; // expected-error{{'c' declared as array of 'auto *'}} + auto a[5] = b; // expected-error{{variable 'a' with type 'auto[5]' has incompatible initializer of type 'int[5]'}} + auto *c[5] = b; // expected-error{{variable 'c' with type 'auto *[5]' has incompatible initializer of type 'int[5]'}} } diff --git a/clang/test/CXX/drs/dr23xx.cpp b/clang/test/CXX/drs/dr23xx.cpp --- a/clang/test/CXX/drs/dr23xx.cpp +++ b/clang/test/CXX/drs/dr23xx.cpp @@ -197,3 +197,14 @@ // void g(A a) { a.operator decltype(B()) B::*(); } // void g2(A a) { a.operator B decltype(B())::*(); } } + +#if __cplusplus >= 201103L +namespace dr2397 { // dr2397: 17 + void foo() { + int a[5]; + + auto (&b)[5] = a; + auto (*c)[5] = &a; + } +} // namespace dr2397 +#endif diff --git a/clang/www/cxx_dr_status.html b/clang/www/cxx_dr_status.html --- a/clang/www/cxx_dr_status.html +++ b/clang/www/cxx_dr_status.html @@ -14189,7 +14189,7 @@ 2397 CD6 auto specifier for pointers and references to arrays - Unknown + Clang 17 2398