Add hasExternalLinkageUncached back with the test that Richard provided, but

keep the call at the current location.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@178741 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 17 insertions, 1 deletions

diff --git a/lib/AST/Decl.cpp b/lib/AST/Decl.cpp
index 9505d299ab..bf807aeb1d 100644
--- a/lib/AST/Decl.cpp
+++ b/lib/AST/Decl.cpp
@@ -866,6 +866,10 @@ bool NamedDecl::isLinkageValid() const {
     Linkage(CachedLinkage);
 }
 
+bool NamedDecl::hasExternalLinkageUncached() const {
+  return getLVForDecl(this, LVForExplicitValue).getLinkage() == ExternalLinkage;
+}
+
 Linkage NamedDecl::getLinkage() const {
   if (HasCachedLinkage)
     return Linkage(CachedLinkage);
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index 0ad539ef17..436fca35cb 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -1614,7 +1614,19 @@ static void filterNonConflictingPreviousDecls(ASTContext &context,
       continue;
 
     // If either has no-external linkage, ignore the old declaration.
-    if (old->getLinkage() != ExternalLinkage || !decl->hasExternalLinkage())
+    // If this declaration would have external linkage if it were the first
+    // declaration of this name, then it may in fact be a redeclaration of
+    // some hidden declaration, so include those too. We don't need to worry
+    // about some previous visible declaration giving this declaration external
+    // linkage, because in that case, we'll mark this declaration as a redecl
+    // of the visible decl, and that decl will already be a redecl of the
+    // hidden declaration if that's appropriate.
+    //
+    // Don't cache this linkage computation, because it's not yet correct: we
+    // may later give this declaration a previous declaration which changes
+    // its linkage.
+    if (old->getLinkage() != ExternalLinkage ||
+        !decl->hasExternalLinkageUncached())
       filter.erase();
   }