Major anonymous union/struct redesign.

A new AST node is introduced:
   def IndirectField : DDecl<Value>;
IndirectFields are injected into the anonymous's parent scope and chain back to
the original field. Name lookup for anonymous entities now result in an
IndirectFieldDecl instead of a FieldDecl.
There is no functionality change, the code generated should be the same.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@119919 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 48 insertions, 3 deletions

diff --git a/lib/AST/ASTImporter.cpp b/lib/AST/ASTImporter.cpp
index 7b16809a1f..980e93c04d 100644
--- a/lib/AST/ASTImporter.cpp
+++ b/lib/AST/ASTImporter.cpp
@@ -98,6 +98,7 @@ namespace {
     Decl *VisitCXXDestructorDecl(CXXDestructorDecl *D);
     Decl *VisitCXXConversionDecl(CXXConversionDecl *D);
     Decl *VisitFieldDecl(FieldDecl *D);
+    Decl *VisitIndirectFieldDecl(IndirectFieldDecl *D);
     Decl *VisitObjCIvarDecl(ObjCIvarDecl *D);
     Decl *VisitVarDecl(VarDecl *D);
     Decl *VisitImplicitParamDecl(ImplicitParamDecl *D);
@@ -2020,6 +2021,42 @@ Decl *ASTNodeImporter::VisitFieldDecl(FieldDecl *D) {
   return ToField;
 }
 
+Decl *ASTNodeImporter::VisitIndirectFieldDecl(IndirectFieldDecl *D) {
+  // Import the major distinguishing characteristics of a variable.
+  DeclContext *DC, *LexicalDC;
+  DeclarationName Name;
+  SourceLocation Loc;
+  if (ImportDeclParts(D, DC, LexicalDC, Name, Loc))
+    return 0;
+
+  // Import the type.
+  QualType T = Importer.Import(D->getType());
+  if (T.isNull())
+    return 0;
+
+  NamedDecl **NamedChain =
+    new (Importer.getToContext())NamedDecl*[D->getChainingSize()];
+
+  unsigned i = 0;
+  for (IndirectFieldDecl::chain_iterator PI = D->chain_begin(),
+       PE = D->chain_end(); PI != PE; ++PI) {
+    Decl* D = Importer.Import(*PI);
+    if (!D)
+      return 0;
+    NamedChain[i++] = cast<NamedDecl>(D);
+  }
+
+  IndirectFieldDecl *ToIndirectField = IndirectFieldDecl::Create(
+                                         Importer.getToContext(), DC,
+                                         Loc, Name.getAsIdentifierInfo(), T,
+                                         NamedChain, D->getChainingSize());
+  ToIndirectField->setAccess(D->getAccess());
+  ToIndirectField->setLexicalDeclContext(LexicalDC);
+  Importer.Imported(D, ToIndirectField);
+  LexicalDC->addDecl(ToIndirectField);
+  return ToIndirectField;
+}
+
 Decl *ASTNodeImporter::VisitObjCIvarDecl(ObjCIvarDecl *D) {
   // Import the major distinguishing characteristics of an ivar.
   DeclContext *DC, *LexicalDC;
diff --git a/lib/AST/Decl.cpp b/lib/AST/Decl.cpp
index c448116ed2..ef8f16861e 100644
--- a/lib/AST/Decl.cpp
+++ b/lib/AST/Decl.cpp
@@ -768,7 +768,7 @@ bool NamedDecl::isCXXInstanceMember() const {
   if (isa<UsingShadowDecl>(D))
     D = cast<UsingShadowDecl>(D)->getTargetDecl();
 
-  if (isa<FieldDecl>(D))
+  if (isa<FieldDecl>(D) || isa<IndirectFieldDecl>(D))
     return true;
   if (isa<CXXMethodDecl>(D))
     return cast<CXXMethodDecl>(D)->isInstance();
@@ -2030,6 +2030,12 @@ EnumConstantDecl *EnumConstantDecl::Create(ASTContext &C, EnumDecl *CD,
   return new (C) EnumConstantDecl(CD, L, Id, T, E, V);
 }
 
+IndirectFieldDecl *IndirectFieldDecl::Create(ASTContext &C, DeclContext *DC,
+                                          SourceLocation L, IdentifierInfo *Id,
+                                          QualType T, NamedDecl **CH, int CHS) {
+  return new (C) IndirectFieldDecl(DC, L, Id, T, CH, CHS);
+}
+
 SourceRange EnumConstantDecl::getSourceRange() const {
   SourceLocation End = getLocation();
   if (Init)
diff --git a/lib/AST/DeclBase.cpp b/lib/AST/DeclBase.cpp
index 5ba6623b20..7d8a92530e 100644
--- a/lib/AST/DeclBase.cpp
+++ b/lib/AST/DeclBase.cpp
@@ -249,6 +249,9 @@ unsigned Decl::getIdentifierNamespaceForKind(Kind DeclKind) {
     case ObjCProperty:
       return IDNS_Ordinary;
 
+    case IndirectField:
+      return IDNS_Ordinary | IDNS_Member;
+
     case ObjCCompatibleAlias:
     case ObjCInterface:
       return IDNS_Ordinary | IDNS_Type;
@@ -524,8 +527,6 @@ bool DeclContext::isTransparentContext() const {
     return !cast<EnumDecl>(this)->isScoped();
   else if (DeclKind == Decl::LinkageSpec)
     return true;
-  else if (DeclKind >= Decl::firstRecord && DeclKind <= Decl::lastRecord)
-    return cast<RecordDecl>(this)->isAnonymousStructOrUnion();
 
   return false;
 }
diff --git a/lib/AST/ExprClassification.cpp b/lib/AST/ExprClassification.cpp
index ba5970038d..bf26bd1f93 100644
--- a/lib/AST/ExprClassification.cpp
+++ b/lib/AST/ExprClassification.cpp
@@ -333,6 +333,7 @@ static Cl::Kinds ClassifyDecl(ASTContext &Ctx, const Decl *D) {
     islvalue = NTTParm->getType()->isReferenceType();
   else
     islvalue = isa<VarDecl>(D) || isa<FieldDecl>(D) ||
+	  isa<IndirectFieldDecl>(D) ||
       (Ctx.getLangOptions().CPlusPlus &&
         (isa<FunctionDecl>(D) || isa<FunctionTemplateDecl>(D)));