PR12585: When processing a friend template inside a class template, don't

pretend there was no previous declaration -- that can lead us to injecting
a class template (with no access specifier) into a class scope. Instead,
just avoid the problematic checks.

llvm-svn: 155303

1 files changed, 12 insertions, 15 deletions

diff --git a/clang/lib/Sema/SemaTemplate.cpp b/clang/lib/Sema/SemaTemplate.cpp
index f1581e0c349..d4b09753d30 100644
--- a/clang/lib/Sema/SemaTemplate.cpp
+++ b/clang/lib/Sema/SemaTemplate.cpp
@@ -969,20 +969,15 @@ Sema::CheckClassTemplate(Scope *S, unsigned TagSpec, TagUseKind TUK,
           PrevDecl = (*Previous.begin())->getUnderlyingDecl();
       }
     }
-
-    if (CurContext->isDependentContext() && PrevClassTemplate) {
-      // If this is a dependent context, we don't want to link the friend
-      // class template to the template in scope, because that would perform
-      // checking of the template parameter lists that can't be performed
-      // until the outer context is instantiated.
-      PrevDecl = PrevClassTemplate = 0;
-    }
   } else if (PrevDecl && !isDeclInScope(PrevDecl, SemanticContext, S))
     PrevDecl = PrevClassTemplate = 0;
 
   if (PrevClassTemplate) {
-    // Ensure that the template parameter lists are compatible.
-    if (!TemplateParameterListsAreEqual(TemplateParams,
+    // Ensure that the template parameter lists are compatible. Skip this check
+    // for a friend in a dependent context: the template parameter list itself
+    // could be dependent.
+    if (!(TUK == TUK_Friend && CurContext->isDependentContext()) &&
+        !TemplateParameterListsAreEqual(TemplateParams,
                                    PrevClassTemplate->getTemplateParameters(),
                                         /*Complain=*/true,
                                         TPL_TemplateMatch))
@@ -1031,8 +1026,10 @@ Sema::CheckClassTemplate(Scope *S, unsigned TagSpec, TagUseKind TUK,
 
   // Check the template parameter list of this declaration, possibly
   // merging in the template parameter list from the previous class
-  // template declaration.
-  if (CheckTemplateParameterList(TemplateParams,
+  // template declaration. Skip this check for a friend in a dependent
+  // context, because the template parameter list might be dependent.
+  if (!(TUK == TUK_Friend && CurContext->isDependentContext()) &&
+      CheckTemplateParameterList(TemplateParams,
             PrevClassTemplate? PrevClassTemplate->getTemplateParameters() : 0,
                                  (SS.isSet() && SemanticContext &&
                                   SemanticContext->isRecord() &&
@@ -1044,9 +1041,9 @@ Sema::CheckClassTemplate(Scope *S, unsigned TagSpec, TagUseKind TUK,
   if (SS.isSet()) {
     // If the name of the template was qualified, we must be defining the
     // template out-of-line.
-    if (!SS.isInvalid() && !Invalid && !PrevClassTemplate &&
-        !(TUK == TUK_Friend && CurContext->isDependentContext())) {
-      Diag(NameLoc, diag::err_member_def_does_not_match)
+    if (!SS.isInvalid() && !Invalid && !PrevClassTemplate) {
+      Diag(NameLoc, TUK == TUK_Friend ? diag::err_friend_decl_does_not_match
+                                      : diag::err_member_def_does_not_match)
         << Name << SemanticContext << SS.getRange();
       Invalid = true;
     }