From: Nathan Wilson <nwilson20@gmail.com>
Date: Wed, 11 Nov 2015 23:53:35 +0000 (+0000)
Subject: Add diagnostics which fall under [dcl.spec.concept]p5
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=7347a6b40a6cf26f318c21303add4ec5f73c8e72;p=clang

Add diagnostics which fall under [dcl.spec.concept]p5

Summary: Diagnose when a function concept declaration has parameter(s)

Reviewers: rsmith, faisalv, aaron.ballman, hubert.reinterpretcast

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D14352

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@252827 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/include/clang/Basic/DiagnosticSemaKinds.td b/include/clang/Basic/DiagnosticSemaKinds.td
index 4306254305..a43923b069 100644
--- a/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/include/clang/Basic/DiagnosticSemaKinds.td
@@ -1994,6 +1994,8 @@ def err_function_concept_exception_spec : Error<
 def err_concept_decl_invalid_specifiers : Error<
   "%select{variable|function}0 concept cannot be declared "
   "'%select{thread_local|inline|friend|constexpr}1'">;
+def err_function_concept_with_params : Error<
+  "function concept cannot have any parameters">;
 
 // C++11 char16_t/char32_t
 def warn_cxx98_compat_unicode_type : Warning<
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index 18d0c3491b..02f96ec0d1 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -7607,6 +7607,13 @@ Sema::ActOnFunctionDeclarator(Scope *S, Declarator &D, DeclContext *DC,
         } else {
           Context.adjustExceptionSpec(NewFD, EST_BasicNoexcept);
         }
+
+        // C++ Concepts TS [dcl.spec.concept]p5: A function concept has the
+        // following restrictions:
+        // - The declaration's parameter list shall be equivalent to an empty
+        //   parameter list.
+        if ((FPT->getNumParams() > 0) || (FPT->isVariadic()))
+          Diag(NewFD->getLocation(), diag::err_function_concept_with_params);
       }
 
       // C++ Concepts TS [dcl.spec.concept]p2: Every concept definition is
diff --git a/test/CXX/concepts-ts/dcl.dcl/dcl.spec/dcl.spec.concept/p5.cpp b/test/CXX/concepts-ts/dcl.dcl/dcl.spec/dcl.spec.concept/p5.cpp
new file mode 100644
index 0000000000..38593bccaf
--- /dev/null
+++ b/test/CXX/concepts-ts/dcl.dcl/dcl.spec/dcl.spec.concept/p5.cpp
@@ -0,0 +1,13 @@
+// RUN:  %clang_cc1 -std=c++14 -fconcepts-ts -x c++ -verify %s
+
+template<typename T>
+concept bool fcpv(void) { return true; }
+
+template<typename T>
+concept bool fcpi(int i = 0) { return true; } // expected-error {{function concept cannot have any parameters}}
+
+template<typename... Ts>
+concept bool fcpp(Ts... ts) { return true; } // expected-error {{function concept cannot have any parameters}}
+
+template<typename T>
+concept bool fcpva(...) { return true; } // expected-error {{function concept cannot have any parameters}}