From: Richard Smith <richard-llvm@metafoo.co.uk>
Date: Thu, 6 Oct 2011 09:21:12 +0000 (+0000)
Subject: PR11067: A definition of a constexpr static variable doesn't need an initializer... 
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=b52c0dddffdb27b3a058913020001afcfc937d8d;p=clang

PR11067: A definition of a constexpr static variable doesn't need an initializer if the in-class declaration had one. Such a declaration must be initialized by a constant expression.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@141279 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/include/clang/Basic/DiagnosticSemaKinds.td b/include/clang/Basic/DiagnosticSemaKinds.td
index 5f36f18656..fc8c636bb3 100644
--- a/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/include/clang/Basic/DiagnosticSemaKinds.td
@@ -1192,8 +1192,6 @@ def err_invalid_constexpr_var_decl : Error<
   "constexpr variable declaration must be a definition">;
 def err_constexpr_var_requires_init : Error<
   "declaration of constexpr variable %0 requires an initializer">;
-def err_constexpr_initialized_static_member : Error<
-  "definition of initialized static data member %0 cannot be marked constexpr">;
 def err_constexpr_var_requires_const_init : Error<
   "constexpr variable %0 must be initialized by a constant expression">;
 def err_constexpr_redecl_mismatch : Error<
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index 1974f30b8e..718a19b988 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -6032,15 +6032,12 @@ void Sema::ActOnUninitializedDecl(Decl *RealDecl,
     // C++0x [class.static.data]p3: A static data member can be declared with
     // the constexpr specifier; if so, its declaration shall specify
     // a brace-or-equal-initializer.
-    if (Var->isConstexpr()) {
-      // FIXME: Provide fix-its to convert the constexpr to const.
-      if (Var->isStaticDataMember() && Var->getAnyInitializer()) {
-        Diag(Var->getLocation(), diag::err_constexpr_initialized_static_member)
-          << Var->getDeclName();
-      } else {
-        Diag(Var->getLocation(), diag::err_constexpr_var_requires_init)
-          << Var->getDeclName();
-      }
+    //
+    // A static data member's definition may inherit an initializer from an
+    // in-class declaration.
+    if (Var->isConstexpr() && !Var->getAnyInitializer()) {
+      Diag(Var->getLocation(), diag::err_constexpr_var_requires_init)
+        << Var->getDeclName();
       Var->setInvalidDecl();
       return;
     }
diff --git a/test/CXX/class/class.static/class.static.data/p3.cpp b/test/CXX/class/class.static/class.static.data/p3.cpp
index 031c376648..82460c5d96 100644
--- a/test/CXX/class/class.static/class.static.data/p3.cpp
+++ b/test/CXX/class/class.static/class.static.data/p3.cpp
@@ -10,6 +10,7 @@ struct S {
 
   static constexpr int c = 0;
   static const int d;
+  static const int d2 = 0;
 
   static constexpr double e = 0.0; // ok
   static const double f = 0.0; // expected-warning {{extension}} expected-note {{use 'constexpr' specifier}}
@@ -17,8 +18,9 @@ struct S {
   static const NonLit h = NonLit(); // expected-error {{must be initialized out of line}}
 };
 
-constexpr int S::a; // expected-error {{definition of initialized static data member 'a' cannot be marked constexpr}}
+constexpr int S::a;
 constexpr int S::b = 0;
 
 const int S::c;
 constexpr int S::d = 0;
+constexpr int S::d2;