When synthesizing a label declaration based on a goto statement that
cannot yet be resolved, be sure to push the new label declaration into
the right place within the identifier chain. Otherwise, name lookup in
C++ gets confused when searching for names that are lexically closer
than the label. Fixes PR9463.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@127623 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/IdentifierResolver.cpp b/lib/Sema/IdentifierResolver.cpp
index 1085622..fcfc053 100644
--- a/lib/Sema/IdentifierResolver.cpp
+++ b/lib/Sema/IdentifierResolver.cpp
@@ -168,6 +168,39 @@
   IDI->AddDecl(D);
 }
 
+void IdentifierResolver::InsertDecl(iterator Pos, NamedDecl *D) {
+  if (Pos == iterator()) {
+    // Simple case: insert at the beginning of the list (which is the
+    // end of the stored vector).
+    AddDecl(D);
+    return;
+  }
+  
+  DeclarationName Name = D->getDeclName();
+  void *Ptr = Name.getFETokenInfo<void>();
+  
+  if (isDeclPtr(Ptr)) {
+    // There's only one element, and we want to insert before it in the list.
+    // Just create the storage for these identifiers and insert them in the
+    // opposite order we normally would.
+    assert(isDeclPtr(Ptr) && "Not a single declaration!");
+    Name.setFETokenInfo(NULL);
+    IdDeclInfo *IDI = &(*IdDeclInfos)[Name];
+    NamedDecl *PrevD = static_cast<NamedDecl*>(Ptr);
+    IDI->AddDecl(D);
+    IDI->AddDecl(PrevD);
+    return;
+  }
+
+  // General case: insert the declaration at the appropriate point in the 
+  // list, which already has at least two elements.
+  IdDeclInfo *IDI = toIdDeclInfo(Ptr);
+  if (Pos.isIterator())
+    IDI->InsertDecl(Pos.getIterator(), D);
+  else
+    IDI->InsertDecl(IDI->decls_begin(), D);
+}
+
 /// RemoveDecl - Unlink the decl from its shadowed decl chain.
 /// The decl must already be part of the decl chain.
 void IdentifierResolver::RemoveDecl(NamedDecl *D) {