From: Richard Smith <richard-llvm@metafoo.co.uk>
Date: Wed, 19 Oct 2011 20:41:51 +0000 (+0000)
Subject: -Wc++98-compat: warn on nontrivial types used in unions and anonymous structs.
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=e7d7c39be90bf654a8da0f53f6682d965426d081;p=clang

-Wc++98-compat: warn on nontrivial types used in unions and anonymous structs.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@142541 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/include/clang/Basic/DiagnosticSemaKinds.td b/include/clang/Basic/DiagnosticSemaKinds.td
index 6823fb0d17..8c70572a74 100644
--- a/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/include/clang/Basic/DiagnosticSemaKinds.td
@@ -897,6 +897,11 @@ def err_illegal_union_or_anon_struct_member : Error<
   "%select{anonymous struct|union}0 member %1 has a non-trivial "
   "%select{constructor|copy constructor|move constructor|copy assignment "
   "operator|move assignment operator|destructor}2">;
+def warn_cxx98_compat_nontrivial_union_or_anon_struct_member : Warning<
+  "%select{anonymous struct|union}0 member %1 with a non-trivial "
+  "%select{constructor|copy constructor|move constructor|copy assignment "
+  "operator|move assignment operator|destructor}2 is incompatible with C++98">,
+  InGroup<CXX98Compat>, DefaultIgnore;
 def note_nontrivial_has_virtual : Note<
   "because type %0 has a virtual %select{member function|base class}1">;
 def note_nontrivial_has_nontrivial : Note<
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index 8cadec5f89..7dafc50b3d 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -2711,7 +2711,7 @@ Decl *Sema::BuildAnonymousStructOrUnion(Scope *S, DeclSpec &DS,
         //   copy constructor, a non-trivial destructor, or a non-trivial copy
         //   assignment operator cannot be a member of a union, nor can an
         //   array of such objects.
-        if (!getLangOptions().CPlusPlus0x && CheckNontrivialField(FD))
+        if (CheckNontrivialField(FD))
           Invalid = true;
       } else if ((*Mem)->isImplicit()) {
         // Any implicit members are fine.
@@ -8558,7 +8558,7 @@ FieldDecl *Sema::CheckFieldDecl(DeclarationName Name, QualType T,
           // destructor, or a non-trivial copy assignment operator
           // cannot be a member of a union, nor can an array of such
           // objects.
-          if (!getLangOptions().CPlusPlus0x && CheckNontrivialField(NewFD))
+          if (CheckNontrivialField(NewFD))
             NewFD->setInvalidDecl();
         }
       }
@@ -8617,7 +8617,8 @@ bool Sema::CheckNontrivialField(FieldDecl *FD) {
         member = CXXDestructor;
 
       if (member != CXXInvalid) {
-        if (getLangOptions().ObjCAutoRefCount && RDecl->hasObjectMember()) {
+        if (!getLangOptions().CPlusPlus0x &&
+            getLangOptions().ObjCAutoRefCount && RDecl->hasObjectMember()) {
           // Objective-C++ ARC: it is an error to have a non-trivial field of
           // a union. However, system headers in Objective-C programs 
           // occasionally have Objective-C lifetime objects within unions,
@@ -8631,11 +8632,13 @@ bool Sema::CheckNontrivialField(FieldDecl *FD) {
             return false;
           }
         }
-        
-        Diag(FD->getLocation(), diag::err_illegal_union_or_anon_struct_member)
-              << (int)FD->getParent()->isUnion() << FD->getDeclName() << member;
+
+        Diag(FD->getLocation(), getLangOptions().CPlusPlus0x ?
+               diag::warn_cxx98_compat_nontrivial_union_or_anon_struct_member :
+               diag::err_illegal_union_or_anon_struct_member)
+          << (int)FD->getParent()->isUnion() << FD->getDeclName() << member;
         DiagnoseNontrivial(RT, member);
-        return true;
+        return !getLangOptions().CPlusPlus0x;
       }
     }
   }
diff --git a/test/SemaCXX/cxx98-compat.cpp b/test/SemaCXX/cxx98-compat.cpp
index ddcc1efe5a..6d3abe8537 100644
--- a/test/SemaCXX/cxx98-compat.cpp
+++ b/test/SemaCXX/cxx98-compat.cpp
@@ -213,3 +213,27 @@ namespace CopyCtorIssues {
   const Ambiguous &c = Ambiguous(); // expected-warning {{copying variable of type 'CopyCtorIssues::Ambiguous' when binding a reference to a temporary would find ambiguous constructors in C++98}}
   const Deleted &d = Deleted(); // expected-warning {{copying variable of type 'CopyCtorIssues::Deleted' when binding a reference to a temporary would invoke a deleted constructor in C++98}}
 }
+
+namespace UnionOrAnonStructMembers {
+  struct NonTrivCtor {
+    NonTrivCtor(); // expected-note 2{{user-declared constructor}}
+  };
+  struct NonTrivCopy {
+    NonTrivCopy(const NonTrivCopy&); // expected-note 2{{user-declared copy constructor}}
+  };
+  struct NonTrivDtor {
+    ~NonTrivDtor(); // expected-note 2{{user-declared destructor}}
+  };
+  union BadUnion {
+    NonTrivCtor ntc; // expected-warning {{union member 'ntc' with a non-trivial constructor is incompatible with C++98}}
+    NonTrivCopy ntcp; // expected-warning {{union member 'ntcp' with a non-trivial copy constructor is incompatible with C++98}}
+    NonTrivDtor ntd; // expected-warning {{union member 'ntd' with a non-trivial destructor is incompatible with C++98}}
+  };
+  struct Wrap {
+    struct {
+      NonTrivCtor ntc; // expected-warning {{anonymous struct member 'ntc' with a non-trivial constructor is incompatible with C++98}}
+      NonTrivCopy ntcp; // expected-warning {{anonymous struct member 'ntcp' with a non-trivial copy constructor is incompatible with C++98}}
+      NonTrivDtor ntd; // expected-warning {{anonymous struct member 'ntd' with a non-trivial destructor is incompatible with C++98}}
+    };
+  };
+}