Move the "current scope" state from the Parser into Action. This

allows Sema some limited access to the current scope, which we only
use in one way: when Sema is performing some kind of declaration that
is not directly driven by the parser (e.g., due to template
instantiatio or lazy declaration of a member), we can find the Scope
associated with a DeclContext, if that DeclContext is still in the
process of being parsed. 

Use this to make the implicit declaration of special member functions
in a C++ class more "scope-less", rather than using the NULL Scope hack.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@107491 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 25 insertions, 0 deletions

diff --git a/lib/Sema/Sema.cpp b/lib/Sema/Sema.cpp
index d520a78abe..3e23ad3030 100644
--- a/lib/Sema/Sema.cpp
+++ b/lib/Sema/Sema.cpp
@@ -385,6 +385,31 @@ Sema::Diag(SourceLocation Loc, const PartialDiagnostic& PD) {
   return Builder;
 }
 
+/// \brief Determines the active Scope associated with the given declaration
+/// context.
+///
+/// This routine maps a declaration context to the active Scope object that
+/// represents that declaration context in the parser. It is typically used
+/// from "scope-less" code (e.g., template instantiation, lazy creation of
+/// declarations) that injects a name for name-lookup purposes and, therefore,
+/// must update the Scope.
+///
+/// \returns The scope corresponding to the given declaraion context, or NULL
+/// if no such scope is open.
+Scope *Sema::getScopeForContext(DeclContext *Ctx) {
+  
+  if (!Ctx)
+    return 0;
+  
+  Ctx = Ctx->getPrimaryContext();
+  for (Scope *S = getCurScope(); S; S = S->getParent()) {
+    if (DeclContext *Entity = static_cast<DeclContext *> (S->getEntity()))
+      if (Ctx == Entity->getPrimaryContext())
+        return S;
+  }
+  
+  return 0;
+}
 
 /// \brief Enter a new function scope
 void Sema::PushFunctionScope() {