[Concepts] Implement a portion of Concepts TS[dcl.spec.concept]p5 and p6:

Diagnose if the return type of a function concept or declaration type of a
variable concept is not bool.

Reviewers: hubert.reinterpretcast

Differential Revision: http://reviews.llvm.org/D16163

llvm-svn: 259159

1 files changed, 17 insertions, 0 deletions

diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index cb79948341f..11d51a09794 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -6001,6 +6001,15 @@ Sema::ActOnVariableDeclarator(Scope *S, Declarator &D, DeclContext *DC,
             << 0 << 3;
         NewVD->setInvalidDecl(true);
       }
+
+      // C++ Concepts TS [dcl.spec.concept]p6: A variable concept has the
+      // following restrictions:
+      // - The declared type shall have the type bool.
+      if (!Context.hasSameType(NewVD->getType(), Context.BoolTy) &&
+          !NewVD->isInvalidDecl()) {
+        Diag(D.getIdentifierLoc(), diag::err_variable_concept_bool_decl);
+        NewVD->setInvalidDecl(true);
+      }
     }
   }
 
@@ -7683,6 +7692,14 @@ Sema::ActOnFunctionDeclarator(Scope *S, Declarator &D, DeclContext *DC,
 
         // C++ Concepts TS [dcl.spec.concept]p5: A function concept has the
         // following restrictions:
+        // - The declared return type shall have the type bool.
+        if (!Context.hasSameType(FPT->getReturnType(), Context.BoolTy)) {
+          Diag(D.getIdentifierLoc(), diag::err_function_concept_bool_ret);
+          NewFD->setInvalidDecl();
+        }
+
+        // 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())