PR12008: defer adding the implicit 'const' to a constexpr member function until

we know whether it is static.

llvm-svn: 172376

1 files changed, 28 insertions, 19 deletions

diff --git a/clang/lib/Sema/SemaOverload.cpp b/clang/lib/Sema/SemaOverload.cpp
index cfabccf5fe3..cc9f4df4476 100644
--- a/clang/lib/Sema/SemaOverload.cpp
+++ b/clang/lib/Sema/SemaOverload.cpp
@@ -1012,28 +1012,37 @@ bool Sema::IsOverload(FunctionDecl *New, FunctionDecl *Old,
   // 13.1p2). While not part of the definition of the signature,
   // this check is important to determine whether these functions
   // can be overloaded.
-  CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old);
-  CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New);
+  CXXMethodDecl *OldMethod = dyn_cast<CXXMethodDecl>(Old);
+  CXXMethodDecl *NewMethod = dyn_cast<CXXMethodDecl>(New);
   if (OldMethod && NewMethod &&
-      !OldMethod->isStatic() && !NewMethod->isStatic() &&
-      (OldMethod->getTypeQualifiers() != NewMethod->getTypeQualifiers() ||
-       OldMethod->getRefQualifier() != NewMethod->getRefQualifier())) {
-    if (!UseUsingDeclRules &&
-        OldMethod->getRefQualifier() != NewMethod->getRefQualifier() &&
-        (OldMethod->getRefQualifier() == RQ_None ||
-         NewMethod->getRefQualifier() == RQ_None)) {
-      // C++0x [over.load]p2:
-      //   - Member function declarations with the same name and the same
-      //     parameter-type-list as well as member function template
-      //     declarations with the same name, the same parameter-type-list, and
-      //     the same template parameter lists cannot be overloaded if any of
-      //     them, but not all, have a ref-qualifier (8.3.5).
-      Diag(NewMethod->getLocation(), diag::err_ref_qualifier_overload)
-        << NewMethod->getRefQualifier() << OldMethod->getRefQualifier();
-      Diag(OldMethod->getLocation(), diag::note_previous_declaration);
+      !OldMethod->isStatic() && !NewMethod->isStatic()) {
+    if (OldMethod->getRefQualifier() != NewMethod->getRefQualifier()) {
+      if (!UseUsingDeclRules &&
+          (OldMethod->getRefQualifier() == RQ_None ||
+           NewMethod->getRefQualifier() == RQ_None)) {
+        // C++0x [over.load]p2:
+        //   - Member function declarations with the same name and the same
+        //     parameter-type-list as well as member function template
+        //     declarations with the same name, the same parameter-type-list, and
+        //     the same template parameter lists cannot be overloaded if any of
+        //     them, but not all, have a ref-qualifier (8.3.5).
+        Diag(NewMethod->getLocation(), diag::err_ref_qualifier_overload)
+          << NewMethod->getRefQualifier() << OldMethod->getRefQualifier();
+        Diag(OldMethod->getLocation(), diag::note_previous_declaration);
+      }
+      return true;
     }
 
-    return true;
+    // We may not have applied the implicit const for a constexpr member
+    // function yet (because we haven't yet resolved whether this is a static
+    // or non-static member function). Add it now, on the assumption that this
+    // is a redeclaration of OldMethod.
+    unsigned NewQuals = NewMethod->getTypeQualifiers();
+    if ((OldMethod->isConstexpr() || NewMethod->isConstexpr()) &&
+        !isa<CXXConstructorDecl>(NewMethod))
+      NewQuals |= Qualifiers::Const;
+    if (OldMethod->getTypeQualifiers() != NewQuals)
+      return true;
   }
 
   // The signatures match; this is not an overload.