aaron.ballman created this revision.
aaron.ballman added reviewers: rsmith, erichkeane, rjmccall.
aaron.ballman requested review of this revision.
Herald added a project: clang.
The parsing code for a typename requirement currently asserts when given
something which is not a valid type-requirement
(http://eel.is/c++draft/expr.prim.req.type#nt:type-requirement). This removes
the assertion to continue on to the proper diagnostic.
This resolves PR53057.
Note that in that PR, it is using `_BitInt(N)` as a dependent type name. This
patch does not attempt to support that as it is not clear that is a valid type
requirement (it does not match the grammar production for one). The workaround
in the PR, however, is definitely valid and works as expected.
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D117560
Files:
clang/lib/Parse/ParseExprCXX.cpp
clang/test/Parser/cxx2a-concepts-requires-expr.cpp
Index: clang/test/Parser/cxx2a-concepts-requires-expr.cpp
===================================================================
--- clang/test/Parser/cxx2a-concepts-requires-expr.cpp
+++ clang/test/Parser/cxx2a-concepts-requires-expr.cpp
@@ -144,3 +144,18 @@
bool r41 = requires { requires (); };
// expected-error@-1 {{expected expression}}
+
+bool r42 = requires { typename long; }; // expected-error {{expected a
qualified name after 'typename'}}
+
+template <int N>
+requires requires {
+ typename _BitInt(N); // expected-error {{expected a qualified name after
'typename'}}
+} using r43 = void;
+
+template <int N>
+using BitInt = _BitInt(N);
+
+template <int N>
+requires requires {
+ typename BitInt<N>; // ok
+} using r44 = void;
Index: clang/lib/Parse/ParseExprCXX.cpp
===================================================================
--- clang/lib/Parse/ParseExprCXX.cpp
+++ clang/lib/Parse/ParseExprCXX.cpp
@@ -3589,7 +3589,7 @@
// We need to consume the typename to allow 'requires { typename a;
}'
SourceLocation TypenameKWLoc = ConsumeToken();
- if (TryAnnotateCXXScopeToken()) {
+ if (TryAnnotateOptionalCXXScopeToken()) {
TPA.Commit();
SkipUntil(tok::semi, tok::r_brace,
SkipUntilFlags::StopBeforeMatch);
break;
Index: clang/test/Parser/cxx2a-concepts-requires-expr.cpp
===================================================================
--- clang/test/Parser/cxx2a-concepts-requires-expr.cpp
+++ clang/test/Parser/cxx2a-concepts-requires-expr.cpp
@@ -144,3 +144,18 @@
bool r41 = requires { requires (); };
// expected-error@-1 {{expected expression}}
+
+bool r42 = requires { typename long; }; // expected-error {{expected a qualified name after 'typename'}}
+
+template <int N>
+requires requires {
+ typename _BitInt(N); // expected-error {{expected a qualified name after 'typename'}}
+} using r43 = void;
+
+template <int N>
+using BitInt = _BitInt(N);
+
+template <int N>
+requires requires {
+ typename BitInt<N>; // ok
+} using r44 = void;
Index: clang/lib/Parse/ParseExprCXX.cpp
===================================================================
--- clang/lib/Parse/ParseExprCXX.cpp
+++ clang/lib/Parse/ParseExprCXX.cpp
@@ -3589,7 +3589,7 @@
// We need to consume the typename to allow 'requires { typename a; }'
SourceLocation TypenameKWLoc = ConsumeToken();
- if (TryAnnotateCXXScopeToken()) {
+ if (TryAnnotateOptionalCXXScopeToken()) {
TPA.Commit();
SkipUntil(tok::semi, tok::r_brace, SkipUntilFlags::StopBeforeMatch);
break;
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