Partial fix for PR7267 based on comments by John McCall on an earlier patch.

This is more targeted, as it simply provides toggle actions for the parser to
turn access checking on and off. We then use these to suppress access checking
only while we parse the template-id (included scope specifier) of an explicit
instantiation and explicit specialization of a class template. The
specialization behavior is an extension, as it seems likely a defect that the
standard did not exempt them as it does explicit instantiations.

This allows the very common practice of specializing trait classes to work for
private, internal types. This doesn't address instantiating or specializing
function templates, although those apparently already partially work.

The naming and style for the Action layer isn't my favorite, comments and
suggestions would be appreciated there.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@106993 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 15 insertions, 0 deletions

diff --git a/lib/Sema/SemaAccess.cpp b/lib/Sema/SemaAccess.cpp
index 7845f6d0a9..e110e3dfa4 100644
--- a/lib/Sema/SemaAccess.cpp
+++ b/lib/Sema/SemaAccess.cpp
@@ -1024,6 +1024,9 @@ static Sema::AccessResult CheckAccess(Sema &S, SourceLocation Loc,
   if (Entity.getAccess() == AS_public)
     return Sema::AR_accessible;
 
+  if (S.SuppressAccessChecking)
+    return Sema::AR_accessible;
+
   // If we're currently parsing a top-level declaration, delay
   // diagnostics.  This is the only case where parsing a declaration
   // can actually change our effective context for the purposes of
@@ -1334,3 +1337,15 @@ void Sema::CheckLookupAccess(const LookupResult &R) {
     }
   }
 }
+
+void Sema::ActOnStartSuppressingAccessChecks() {
+  assert(!SuppressAccessChecking &&
+         "Tried to start access check suppression when already started.");
+  SuppressAccessChecking = true;
+}
+
+void Sema::ActOnStopSuppressingAccessChecks() {
+  assert(SuppressAccessChecking &&
+         "Tried to stop access check suprression when already stopped.");
+  SuppressAccessChecking = false;
+}