[PATCH] D11027: [CONCEPTS] Creating Diagnostics for ill-formed function concept declaration

[Hubert Tong]

hubert.reinterpretcast added inline comments.

================
Comment at: include/clang/Basic/DiagnosticSemaKinds.td:1964
@@ +1963,3 @@
+def err_invalid_concept_scope : Error<
+  "concept declaration required to be in namespace scope">;
+def err_function_concept_not_defined : Error<
----------------
This error is similar to `err_objc_decls_may_only_appear_in_global_scope` below, so perhaps it could be expressed in a similar manner.

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Comment at: include/clang/Basic/DiagnosticSemaKinds.td:1966
@@ +1965,3 @@
+def err_function_concept_not_defined : Error<
+  "function concept requires definition">;
+
----------------
Perhaps: "can only declare a function concept with its definition".

The existing wording seems to imply that an earlier definition (of just one somewhere) is sufficient and that function concepts may be redeclared.

================
Comment at: lib/Sema/SemaDecl.cpp:7453
@@ +7452,3 @@
+      // C++ Concepts TS [dcl.spec.concept]p1: A concept definition refers to a
+      // function concept and its definition
+      if (!D.isFunctionDefinition()) {
----------------
The quoted text is a definition of the term "concept definition". The diagnosable rule is established by the quote on line 7444. So there probably should be a comment here to the effect of "we are checking that the declaration is indeed a definition".

================
Comment at: lib/Sema/SemaDecl.cpp:7460
@@ +7459,3 @@
+
+      // C++ Concepts TS [dcl.spec.concept]p2: Every concepts definition is
+      // implicity defined to be a constexpr declaration (implicitly inline)
----------------
Typo: s/concepts/concept/

================
Comment at: test/SemaCXX/cxx-concept-declaration.cpp:3
@@ +2,3 @@
+
+template<typename T> concept bool C1 = true;
+
----------------
I'm not sure why this is part of the current patch.

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Comment at: test/SemaCXX/cxx-concept-declaration.cpp:5
@@ +4,3 @@
+
+template<typename T> concept decltype(!0) C2 = true;
+
----------------
Same comment as on line 3.


http://reviews.llvm.org/D11027