r339375 - [Sema] P0961R1: Relaxing the structured bindings customization point finding rules
Erik Pilkington via cfe-commits
cfe-commits at lists.llvm.org
Thu Aug 9 13:11:13 PDT 2018
Author: epilk
Date: Thu Aug 9 13:11:13 2018
New Revision: 339375
URL: http://llvm.org/viewvc/llvm-project?rev=339375&view=rev
Log:
[Sema] P0961R1: Relaxing the structured bindings customization point finding rules
Differential revision: https://reviews.llvm.org/D50418
Modified:
cfe/trunk/lib/Sema/SemaDeclCXX.cpp
cfe/trunk/test/CXX/dcl.decl/dcl.decomp/p3.cpp
cfe/trunk/www/cxx_status.html
Modified: cfe/trunk/lib/Sema/SemaDeclCXX.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDeclCXX.cpp?rev=339375&r1=339374&r2=339375&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaDeclCXX.cpp (original)
+++ cfe/trunk/lib/Sema/SemaDeclCXX.cpp Thu Aug 9 13:11:13 2018
@@ -1108,7 +1108,7 @@ static bool checkTupleLikeDecomposition(
// [dcl.decomp]p3:
// The unqualified-id get is looked up in the scope of E by class member
- // access lookup
+ // access lookup ...
LookupResult MemberGet(S, GetDN, Src->getLocation(), Sema::LookupMemberName);
bool UseMemberGet = false;
if (S.isCompleteType(Src->getLocation(), DecompType)) {
@@ -1116,7 +1116,20 @@ static bool checkTupleLikeDecomposition(
S.LookupQualifiedName(MemberGet, RD);
if (MemberGet.isAmbiguous())
return true;
- UseMemberGet = !MemberGet.empty();
+ // ... and if that finds at least one declaration that is a function
+ // template whose first template parameter is a non-type parameter ...
+ for (NamedDecl *D : MemberGet) {
+ if (FunctionTemplateDecl *FTD =
+ dyn_cast<FunctionTemplateDecl>(D->getUnderlyingDecl())) {
+ TemplateParameterList *TPL = FTD->getTemplateParameters();
+ if (TPL->size() != 0 &&
+ isa<NonTypeTemplateParmDecl>(TPL->getParam(0))) {
+ // ... the initializer is e.get<i>().
+ UseMemberGet = true;
+ break;
+ }
+ }
+ }
S.FilterAcceptableTemplateNames(MemberGet);
}
Modified: cfe/trunk/test/CXX/dcl.decl/dcl.decomp/p3.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CXX/dcl.decl/dcl.decomp/p3.cpp?rev=339375&r1=339374&r2=339375&view=diff
==============================================================================
--- cfe/trunk/test/CXX/dcl.decl/dcl.decomp/p3.cpp (original)
+++ cfe/trunk/test/CXX/dcl.decl/dcl.decomp/p3.cpp Thu Aug 9 13:11:13 2018
@@ -36,7 +36,7 @@ void no_get_2() {
auto [a0, a1, a2] = A(); // expected-error {{undeclared identifier 'get'}} expected-note {{in implicit initialization of binding declaration 'a0'}}
}
-template<int> float &get(A);
+template<int> float &get(A); // expected-note 2 {{no known conversion}}
void no_tuple_element_1() {
auto [a0, a1, a2] = A(); // expected-error-re {{'std::tuple_element<0U{{L*}}, A>::type' does not name a type}} expected-note {{in implicit}}
@@ -57,7 +57,7 @@ void no_tuple_element_3() {
template<> struct std::tuple_element<1, A> { typedef float &type; };
template<> struct std::tuple_element<2, A> { typedef const float &type; };
-template<int N> auto get(B) -> int (&)[N + 1];
+template<int N> auto get(B) -> int (&)[N + 1]; // expected-note 2 {{no known conversion}}
template<int N> struct std::tuple_element<N, B> { typedef int type[N +1 ]; };
template<typename T> struct std::tuple_size<const T> : std::tuple_size<T> {};
@@ -138,19 +138,25 @@ int member_get() {
return c;
}
-struct D { template<int> struct get {}; }; // expected-note {{declared here}}
+struct D {
+ // FIXME: Emit a note here explaining why this was ignored.
+ template<int> struct get {};
+};
template<> struct std::tuple_size<D> { static const int value = 1; };
template<> struct std::tuple_element<0, D> { typedef D::get<0> type; };
void member_get_class_template() {
- auto [d] = D(); // expected-error {{cannot refer to member 'get' in 'D' with '.'}} expected-note {{in implicit init}}
+ auto [d] = D(); // expected-error {{no matching function for call to 'get'}} expected-note {{in implicit init}}
}
-struct E { int get(); };
+struct E {
+ // FIXME: Emit a note here explaining why this was ignored.
+ int get();
+};
template<> struct std::tuple_size<E> { static const int value = 1; };
template<> struct std::tuple_element<0, E> { typedef int type; };
void member_get_non_template() {
// FIXME: This diagnostic is not very good.
- auto [e] = E(); // expected-error {{no member named 'get'}} expected-note {{in implicit init}}
+ auto [e] = E(); // expected-error {{no matching function for call to 'get'}} expected-note {{in implicit init}}
}
namespace ADL {
@@ -230,3 +236,62 @@ namespace constant {
}
static_assert(g() == 4); // expected-error {{constant}} expected-note {{in call to 'g()'}}
}
+
+// P0961R1
+struct InvalidMemberGet {
+ int get();
+ template <class T> int get();
+ struct get {};
+};
+template <> struct std::tuple_size<InvalidMemberGet> { static constexpr size_t value = 1; };
+template <> struct std::tuple_element<0, InvalidMemberGet> { typedef float type; };
+template <size_t> float get(InvalidMemberGet) { return 0; }
+int f() {
+ InvalidMemberGet img;
+ auto [x] = img;
+ typedef decltype(x) same_as_float;
+ typedef float same_as_float;
+}
+
+struct ValidMemberGet {
+ int get();
+ template <class T> int get() { return 0; }
+ template <size_t N> float get() { return 0; }
+};
+template <> struct std::tuple_size<ValidMemberGet> { static constexpr size_t value = 1; };
+template <> struct std::tuple_element<0, ValidMemberGet> { typedef float type; };
+// Don't use this one; we should use the member get.
+template <size_t N> int get(ValidMemberGet) { static_assert(N && false, ""); }
+int f2() {
+ ValidMemberGet img;
+ auto [x] = img;
+ typedef decltype(x) same_as_float;
+ typedef float same_as_float;
+}
+
+struct Base1 {
+ int get(); // expected-note{{member found by ambiguous name lookup}}
+};
+struct Base2 {
+ template<int> int get(); // expected-note{{member found by ambiguous name lookup}}
+};
+struct Derived : Base1, Base2 {};
+
+template <> struct std::tuple_size<Derived> { static constexpr size_t value = 1; };
+template <> struct std::tuple_element<0, Derived> { typedef int type; };
+
+auto [x] = Derived(); // expected-error{{member 'get' found in multiple base classes of different types}}
+
+struct Base {
+ template<int> int get();
+};
+struct UsingGet : Base {
+ using Base::get;
+};
+
+template <> struct std::tuple_size<UsingGet> {
+ static constexpr size_t value = 1;
+};
+template <> struct std::tuple_element<0, UsingGet> { typedef int type; };
+
+auto [y] = UsingGet();
Modified: cfe/trunk/www/cxx_status.html
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/www/cxx_status.html?rev=339375&r1=339374&r2=339375&view=diff
==============================================================================
--- cfe/trunk/www/cxx_status.html (original)
+++ cfe/trunk/www/cxx_status.html Thu Aug 9 13:11:13 2018
@@ -755,7 +755,7 @@ version 3.7.
<tr>
<!-- from Jacksonville 2018 -->
<td><a href="http://wg21.link/p0961r1">P0961R1</a> (<a href="#dr">DR</a>)</td>
- <td class="none" align="center">No</td>
+ <td class="none" align="center">SVN</td>
</tr>
<tr>
<!-- from Jacksonville 2018 -->
More information about the cfe-commits
mailing list