commit fd8634a09de716f6de7b6699d6f4287056551525
author Richard Smith <richard-llvm@metafoo.co.uk> Wed Oct 23 02:17:46 2013 +0000
committer Richard Smith <richard-llvm@metafoo.co.uk> Wed Oct 23 02:17:46 2013 +0000
tree d600133b3c296a3bd9256b843810c95921b2afd3
parent c89e4ca3c181b907562afa3e88be74366cf65bd2

Make UsingShadowDecls redeclarable. This fixes some visibility problems with
modules.

With this fixed, I no longer see any test regressions in the libc++ test suite
when enabling a single-module module.map for libc++ (other than issues with my
system headers).

llvm-svn: 193219

clang/lib/Sema/SemaTemplateInstantiateDecl.cpp

diff --git a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
index b517164..d0c3ac6 100644
--- a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -2152,19 +2152,22 @@
          I != E; ++I) {
     UsingShadowDecl *Shadow = *I;
     NamedDecl *InstTarget =
-      cast_or_null<NamedDecl>(SemaRef.FindInstantiatedDecl(
-                                                          Shadow->getLocation(),
-                                                        Shadow->getTargetDecl(),
-                                                           TemplateArgs));
+        cast_or_null<NamedDecl>(SemaRef.FindInstantiatedDecl(
+            Shadow->getLocation(), Shadow->getTargetDecl(), TemplateArgs));
     if (!InstTarget)
       return 0;
 
-    if (CheckRedeclaration &&
-        SemaRef.CheckUsingShadowDecl(NewUD, InstTarget, Prev))
-      continue;
+    UsingShadowDecl *PrevDecl = 0;
+    if (CheckRedeclaration) {
+      if (SemaRef.CheckUsingShadowDecl(NewUD, InstTarget, Prev, PrevDecl))
+        continue;
+    } else if (UsingShadowDecl *OldPrev = Shadow->getPreviousDecl()) {
+      PrevDecl = cast_or_null<UsingShadowDecl>(SemaRef.FindInstantiatedDecl(
+          Shadow->getLocation(), OldPrev, TemplateArgs));
+    }
 
-    UsingShadowDecl *InstShadow
-      = SemaRef.BuildUsingShadowDecl(/*Scope*/ 0, NewUD, InstTarget);
+    UsingShadowDecl *InstShadow =
+        SemaRef.BuildUsingShadowDecl(/*Scope*/0, NewUD, InstTarget, PrevDecl);
     SemaRef.Context.setInstantiatedFromUsingShadowDecl(InstShadow, Shadow);
 
     if (isFunctionScope)