Fix constexpr handling to allow 'extern constexpr' variable declarations. We no

longer have access to the source locations we need to produce the
'replace constexpr with const' fixits, so they're gone for now.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@147273 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index d9d7f0a99df7f981937afd47dea5e8c21fff790d..00c6b9fcf093933492586021f84e162b1231bf41 100644 (file)
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -3948,38 +3948,8 @@ Sema::ActOnVariableDeclarator(Scope *S, Declarator &D, DeclContext *DC,
                                            TemplateParamLists.release());
     }
 
-    if (D.getDeclSpec().isConstexprSpecified()) {
-      // FIXME: once we know whether there's an initializer, apply this to
-      // static data members too.
-      if (!NewVD->isStaticDataMember() &&
-          !NewVD->isThisDeclarationADefinition()) {
-        // 'constexpr' is redundant and ill-formed on a non-defining declaration
-        // of a variable. Suggest replacing it with 'const' if appropriate.
-        SourceLocation ConstexprLoc = D.getDeclSpec().getConstexprSpecLoc();
-        SourceRange ConstexprRange(ConstexprLoc, ConstexprLoc);
-        // If the declarator is complex, we need to move the keyword to the
-        // innermost chunk as we switch it from 'constexpr' to 'const'.
-        int Kind = DeclaratorChunk::Paren;
-        for (unsigned I = 0, E = D.getNumTypeObjects(); I != E; ++I) {
-          Kind = D.getTypeObject(I).Kind;
-          if (Kind != DeclaratorChunk::Paren)
-            break;
-        }
-        if ((D.getDeclSpec().getTypeQualifiers() & DeclSpec::TQ_const) ||
-            Kind == DeclaratorChunk::Reference)
-          Diag(ConstexprLoc, diag::err_invalid_constexpr_var_decl)
-            << FixItHint::CreateRemoval(ConstexprRange);
-        else if (Kind == DeclaratorChunk::Paren)
-          Diag(ConstexprLoc, diag::err_invalid_constexpr_var_decl)
-            << FixItHint::CreateReplacement(ConstexprRange, "const");
-        else
-          Diag(ConstexprLoc, diag::err_invalid_constexpr_var_decl)
-            << FixItHint::CreateRemoval(ConstexprRange)
-            << FixItHint::CreateInsertion(D.getIdentifierLoc(), "const ");
-      } else {
-        NewVD->setConstexpr(true);
-      }
-    }
+    if (D.getDeclSpec().isConstexprSpecified())
+      NewVD->setConstexpr(true);
   }
 
   // Set the lexical context. If the declarator has a C++ scope specifier, the
@@ -6244,7 +6214,7 @@ void Sema::ActOnUninitializedDecl(Decl *RealDecl,
   if (VarDecl *Var = dyn_cast<VarDecl>(RealDecl)) {
     QualType Type = Var->getType();
 
-    // C++0x [dcl.spec.auto]p3
+    // C++11 [dcl.spec.auto]p3
     if (TypeMayContainAuto && Type->getContainedAutoType()) {
       Diag(Var->getLocation(), diag::err_auto_var_requires_init)
         << Var->getDeclName() << Type;
@@ -6252,13 +6222,19 @@ void Sema::ActOnUninitializedDecl(Decl *RealDecl,
       return;
     }
 
-    // C++0x [class.static.data]p3: A static data member can be declared with
+    // C++11 [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() && Var->isStaticDataMember() &&
-        !Var->isThisDeclarationADefinition()) {
-      Diag(Var->getLocation(), diag::err_constexpr_static_mem_var_requires_init)
-        << Var->getDeclName();
+    // C++11 [dcl.constexpr]p1: The constexpr specifier shall be applied only to
+    // the definition of a variable [...] or the declaration of a static data
+    // member.
+    if (Var->isConstexpr() && !Var->isThisDeclarationADefinition()) {
+      if (Var->isStaticDataMember())
+        Diag(Var->getLocation(),
+             diag::err_constexpr_static_mem_var_requires_init)
+          << Var->getDeclName();
+      else
+        Diag(Var->getLocation(), diag::err_invalid_constexpr_var_decl);
       Var->setInvalidDecl();
       return;
     }

diff --git a/test/FixIt/fixit-cxx0x.cpp b/test/FixIt/fixit-cxx0x.cpp
index 9fb647d03fcd6ba7cc19db5781bbc4d028df8fb4..b2b69b6f4b7302e3f10e44798565fb8871bbc237 100644 (file)
--- a/test/FixIt/fixit-cxx0x.cpp
+++ b/test/FixIt/fixit-cxx0x.cpp
@@ -18,41 +18,6 @@ using ::T = void; // expected-error {{name defined in alias declaration must be
 using typename U = void; // expected-error {{name defined in alias declaration must be an identifier}}
 using typename ::V = void; // expected-error {{name defined in alias declaration must be an identifier}}
 
-namespace Constexpr {
-  extern constexpr int a; // expected-error {{must be a definition}}
-  // -> extern const int a;
-
-  extern constexpr int *b; // expected-error {{must be a definition}}
-  // -> extern int *const b;
-
-  extern constexpr int &c; // expected-error {{must be a definition}}
-  // -> extern int &b;
-
-  extern constexpr const int d; // expected-error {{must be a definition}}
-  // -> extern const int d;
-
-  int z;
-  constexpr int a = 0;
-  constexpr int *b = &z;
-  constexpr int &c = z;
-  constexpr int d = a;
-
-  // FIXME: Provide FixIts for static data members too.
-#if 0
-  struct S {
-    static constexpr int b; // xpected-error {{requires an initializer}}
-    // -> const int b;
-  };
-
-  constexpr int S::b = 0;
-#endif
-
-  struct S {
-    static char *const p = 0; // expected-error {{requires 'constexpr' specifier}}
-    // -> constexpr static char *const p = 0;
-  };
-}
-
 namespace SemiCommaTypo {
   int m {},
   n [[]], // expected-error {{expected ';' at end of declaration}}

diff --git a/test/SemaCXX/constant-expression-cxx11.cpp b/test/SemaCXX/constant-expression-cxx11.cpp
index 0993a982d8e13413f4ce4b6e40fe278f3ae877d4..d78c16cca62608959e4cf003db7f71dfb056d74f 100644 (file)
--- a/test/SemaCXX/constant-expression-cxx11.cpp
+++ b/test/SemaCXX/constant-expression-cxx11.cpp
@@ -961,3 +961,13 @@ struct S {
 };
 
 }
+
+namespace ExternConstexpr {
+  extern constexpr int n = 0;
+  extern constexpr int m; // expected-error {{constexpr variable declaration must be a definition}}
+  void f() {
+    extern constexpr int i; // expected-error {{constexpr variable declaration must be a definition}}
+    constexpr int j = 0;
+    constexpr int k; // expected-error {{default initialization of an object of const type}}
+  }
+}