Emit diagnostic error when the field of an anonymous struct is non trivial.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@111158 91177308-0d34-0410-b5e6-96231b3b80d8

include/clang/Basic/DiagnosticSemaKinds.td

@@ -633,9 +633,9 @@ def err_missing_default_ctor : Error<
   "%select{|implicit default }0constructor for %1 must explicitly initialize "
   "the %select{base class|member}2 %3 which does not have a default "
   "constructor">;
-def err_illegal_union_member : Error<
-  "union member %0 has a non-trivial %select{constructor|"
-  "copy constructor|copy assignment operator|destructor}1">;
+def err_illegal_union_or_anon_struct_member : Error<
+  "%select{anonymous struct|union}0 member %1 has a non-trivial "
+  "%select{constructor|copy constructor|copy assignment operator|destructor}2">;
 def note_nontrivial_has_virtual : Note<
   "because type %0 has a virtual %select{member function|base class}1">;
 def note_nontrivial_has_nontrivial : Note<

include/clang/Sema/Sema.h

@@ -1019,6 +1019,7 @@ public:
     CXXCopyAssignment = 2,
     CXXDestructor = 3
   };
+  bool CheckNontrivialField(FieldDecl *FD);
   void DiagnoseNontrivial(const RecordType* Record, CXXSpecialMember mem);
   CXXSpecialMember getSpecialMember(const CXXMethodDecl *MD);
 

lib/Sema/SemaDecl.cpp

@@ -1855,6 +1855,9 @@ Sema::DeclPtrTy Sema::BuildAnonymousStructOrUnion(Scope *S, DeclSpec &DS,
             << (int)Record->isUnion() << (int)(FD->getAccess() == AS_protected);
           Invalid = true;
         }
+
+        if (CheckNontrivialField(FD))
+          Invalid = true;
       } else if ((*Mem)->isImplicit()) {
         // Any implicit members are fine.
       } else if (isa<TagDecl>(*Mem) && (*Mem)->getDeclContext() != Record) {
@@ -6044,27 +6047,8 @@ FieldDecl *Sema::CheckFieldDecl(DeclarationName Name, QualType T,
         // cannot be a member of a union, nor can an array of such
         // objects.
         // TODO: C++0x alters this restriction significantly.
-        if (Record->isUnion()) {
-          // We check for copy constructors before constructors
-          // because otherwise we'll never get complaints about
-          // copy constructors.
-
-          CXXSpecialMember member = CXXInvalid;
-          if (!RDecl->hasTrivialCopyConstructor())
-            member = CXXCopyConstructor;
-          else if (!RDecl->hasTrivialConstructor())
-            member = CXXConstructor;
-          else if (!RDecl->hasTrivialCopyAssignment())
-            member = CXXCopyAssignment;
-          else if (!RDecl->hasTrivialDestructor())
-            member = CXXDestructor;
-
-          if (member != CXXInvalid) {
-            Diag(Loc, diag::err_illegal_union_member) << Name << member;
-            DiagnoseNontrivial(RT, member);
-            NewFD->setInvalidDecl();
-          }
-        }
+        if (Record->isUnion() && CheckNontrivialField(NewFD))
+          NewFD->setInvalidDecl();
       }
     }
   }
@@ -6094,6 +6078,43 @@ FieldDecl *Sema::CheckFieldDecl(DeclarationName Name, QualType T,
   return NewFD;
 }
 
+bool Sema::CheckNontrivialField(FieldDecl *FD) {
+  assert(FD);
+  assert(getLangOptions().CPlusPlus && "valid check only for C++");
+
+  if (FD->isInvalidDecl())
+    return true;
+
+  QualType EltTy = Context.getBaseElementType(FD->getType());
+  if (const RecordType *RT = EltTy->getAs<RecordType>()) {
+    CXXRecordDecl* RDecl = cast<CXXRecordDecl>(RT->getDecl());
+    if (RDecl->getDefinition()) {
+      // We check for copy constructors before constructors
+      // because otherwise we'll never get complaints about
+      // copy constructors.
+
+      CXXSpecialMember member = CXXInvalid;
+      if (!RDecl->hasTrivialCopyConstructor())
+        member = CXXCopyConstructor;
+      else if (!RDecl->hasTrivialConstructor())
+        member = CXXConstructor;
+      else if (!RDecl->hasTrivialCopyAssignment())
+        member = CXXCopyAssignment;
+      else if (!RDecl->hasTrivialDestructor())
+        member = CXXDestructor;
+
+      if (member != CXXInvalid) {
+        Diag(FD->getLocation(), diag::err_illegal_union_or_anon_struct_member)
+              << (int)FD->getParent()->isUnion() << FD->getDeclName() << member;
+        DiagnoseNontrivial(RT, member);
+        return true;
+      }
+    }
+  }
+  
+  return false;
+}
+
 /// DiagnoseNontrivial - Given that a class has a non-trivial
 /// special member, figure out why.
 void Sema::DiagnoseNontrivial(const RecordType* T, CXXSpecialMember member) {

test/SemaCXX/anonymous-struct.cpp

@@ -0,0 +1,11 @@
+// RUN: %clang_cc1 -fsyntax-only -verify %s
+
+struct S {
+  S();  // expected-note {{because type 'S' has a user-declared constructor}}    
+};
+
+struct E {
+  struct {
+    S x;  // expected-error {{anonymous struct member 'x' has a non-trivial constructor}} 
+  };
+};