From 5149f37cfc736d03233bf92b5ba7c6e866c6647b Mon Sep 17 00:00:00 2001
From: Douglas Gregor <dgregor@apple.com>
Date: Fri, 25 Feb 2011 15:54:31 +0000
Subject: [PATCH] Maintain nested-name-specifier source-location information
 through instantiation of using declarations (all three forms).

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@126485 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Sema/SemaTemplateInstantiateDecl.cpp    | 40 +++++++++-----------
 test/SemaCXX/nested-name-spec-locations.cpp | 42 +++++++++++++++++++++
 2 files changed, 59 insertions(+), 23 deletions(-)
 create mode 100644 test/SemaCXX/nested-name-spec-locations.cpp

diff --git a/lib/Sema/SemaTemplateInstantiateDecl.cpp b/lib/Sema/SemaTemplateInstantiateDecl.cpp
index f437cd3092..c96430a5d5 100644
--- a/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -1661,11 +1661,10 @@ Decl *TemplateDeclInstantiator::VisitUsingDecl(UsingDecl *D) {
   //     template struct t<int>;
   // Here, in using s1::f1, s1 refers to t<T>::s1;
   // we need to substitute for t<int>::s1.
-  NestedNameSpecifier *NNS 
-    = SemaRef.SubstNestedNameSpecifier(D->getQualifier(), 
-                                       D->getQualifierRange(),
-                                       TemplateArgs);
-  if (!NNS)
+  NestedNameSpecifierLoc QualifierLoc
+    = SemaRef.SubstNestedNameSpecifierLoc(D->getQualifierLoc(),
+                                          TemplateArgs);
+  if (!QualifierLoc)
     return 0;
 
   // The name info is non-dependent, so no transformation
@@ -1680,18 +1679,14 @@ Decl *TemplateDeclInstantiator::VisitUsingDecl(UsingDecl *D) {
   LookupResult Prev(SemaRef, NameInfo, Sema::LookupUsingDeclName,
                     Sema::ForRedeclaration);
 
-  CXXScopeSpec SS;
-  if (NNS == D->getQualifier())
-    SS.Adopt(D->getQualifierLoc());
-  else
-    SS.MakeTrivial(SemaRef.Context, NNS, D->getQualifierRange());
-
   UsingDecl *NewUD = UsingDecl::Create(SemaRef.Context, Owner,
                                        D->getUsingLocation(),
-                                       SS.getWithLocInContext(SemaRef.Context),
+                                       QualifierLoc,
                                        NameInfo,
                                        D->isTypeName());
 
+  CXXScopeSpec SS;
+  SS.Adopt(QualifierLoc);
   if (CheckRedeclaration) {
     Prev.setHideTags(false);
     SemaRef.LookupQualifiedName(Prev, Owner);
@@ -1750,14 +1745,14 @@ Decl *TemplateDeclInstantiator::VisitUsingShadowDecl(UsingShadowDecl *D) {
 
 Decl * TemplateDeclInstantiator
     ::VisitUnresolvedUsingTypenameDecl(UnresolvedUsingTypenameDecl *D) {
-  NestedNameSpecifier *NNS =
-    SemaRef.SubstNestedNameSpecifier(D->getQualifier(), D->getQualifierRange(),
-                                     TemplateArgs);
-  if (!NNS)
+  NestedNameSpecifierLoc QualifierLoc
+    = SemaRef.SubstNestedNameSpecifierLoc(D->getQualifierLoc(), 
+                                          TemplateArgs);
+  if (!QualifierLoc)
     return 0;
 
   CXXScopeSpec SS;
-  SS.MakeTrivial(SemaRef.Context, NNS, D->getQualifierRange());
+  SS.Adopt(QualifierLoc);
 
   // Since NameInfo refers to a typename, it cannot be a C++ special name.
   // Hence, no tranformation is required for it.
@@ -1775,14 +1770,13 @@ Decl * TemplateDeclInstantiator
 
 Decl * TemplateDeclInstantiator
     ::VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D) {
-  NestedNameSpecifier *NNS =
-    SemaRef.SubstNestedNameSpecifier(D->getQualifier(), D->getQualifierRange(),
-                                     TemplateArgs);
-  if (!NNS)
+  NestedNameSpecifierLoc QualifierLoc
+      = SemaRef.SubstNestedNameSpecifierLoc(D->getQualifierLoc(), TemplateArgs);
+  if (!QualifierLoc)
     return 0;
-
+  
   CXXScopeSpec SS;
-  SS.MakeTrivial(SemaRef.Context, NNS, D->getQualifierRange());
+  SS.Adopt(QualifierLoc);
 
   DeclarationNameInfo NameInfo
     = SemaRef.SubstDeclarationNameInfo(D->getNameInfo(), TemplateArgs);
diff --git a/test/SemaCXX/nested-name-spec-locations.cpp b/test/SemaCXX/nested-name-spec-locations.cpp
new file mode 100644
index 0000000000..f0f42f754c
--- /dev/null
+++ b/test/SemaCXX/nested-name-spec-locations.cpp
@@ -0,0 +1,42 @@
+// RUN: %clang-cc1 -fsyntax-only -verify %s
+
+// Note: the formatting in this test case is intentionally funny, with
+// nested-name-specifiers stretched out vertically so that we can
+// match up diagnostics per-line and still verify that we're getting
+// good source-location information.
+
+namespace outer {
+  namespace inner {
+    template<typename T>
+    struct X0 {
+    };
+  }
+}
+
+template<typename T>
+struct add_reference {
+  typedef T& type;
+};
+
+namespace outer_alias = outer;
+
+template<typename T>
+struct UnresolvedUsingValueDeclTester {
+  using outer::inner::X0<
+          typename add_reference<T>::type 
+    * // expected-error{{declared as a pointer to a reference of type}}
+        >::value;
+};
+
+UnresolvedUsingValueDeclTester<int> UnresolvedUsingValueDeclCheck; // expected-note{{in instantiation of template class}}
+
+template<typename T>
+struct UnresolvedUsingTypenameDeclTester {
+  using outer::inner::X0<
+          typename add_reference<T>::type 
+    * // expected-error{{declared as a pointer to a reference of type}}
+        >::value;
+};
+
+UnresolvedUsingTypenameDeclTester<int> UnresolvedUsingTypenameDeclCheck; // expected-note{{in instantiation of template class}}
+
-- 
2.40.0