[clang-rename] Rename alias.

[hokein]

Summary

• Support rename alias.
• Add unittests for renaming alias.
• Don't generate fixes for the SourceLocations that are invalid or in temporary buffer, otherwise crash would be happened when generating AtomicChanges.

[ioeric]

Lg

cfe/trunk/lib/Tooling/Refactoring/Rename/USRLocFinder.cpp

 
 using namespace llvm;
 
 namespace clang {
 namespace tooling {
 
 namespace {
 
+// Returns true if the given Loc is valid for edit. We don't edit the
+// SourceLocations that are valid or in temporary buffer.
+bool IsValidEditLoc(const clang::SourceManager& SM, clang::SourceLocation Loc) {
+  if (Loc.isInvalid())
+    return false;
+  const clang::FullSourceLoc FullLoc(Loc, SM);
+  std::pair<clang::FileID, unsigned> FileIdAndOffset =
+      FullLoc.getSpellingLoc().getDecomposedLoc();
+  return SM.getFileEntryForID(FileIdAndOffset.first) != nullptr;
+}
+
 // \brief This visitor recursively searches for all instances of a USR in a
 // translation unit and stores them for later usage.
 class USRLocFindingASTVisitor
     : public RecursiveSymbolVisitor<USRLocFindingASTVisitor> {
 public:
   explicit USRLocFindingASTVisitor(const std::vector<std::string> &USRs,
                                    StringRef PrevName,
                                    const ASTContext &Context)
bool VisitNamedDecl(const NamedDecl *Decl) {
     // DestructorDecl has been handled in Typeloc.
     if (llvm::isa<CXXDestructorDecl>(Decl))
       return true;
 
     if (Decl->isImplicit())
       return true;
 
     if (isInUSRSet(Decl)) {
-      RenameInfo Info = {Decl->getLocation(),
-                         Decl->getLocation(),
+      // For the case of renaming an alias template, we actually rename the
+      // underlying alias declaration of the template.
+      if (const auto* TAT = dyn_cast<TypeAliasTemplateDecl>(Decl))
+        Decl = TAT->getTemplatedDecl();
+
+      auto StartLoc = Decl->getLocation();
+      auto EndLoc = StartLoc;
+      if (IsValidEditLoc(Context.getSourceManager(), StartLoc)) {
+        RenameInfo Info = {StartLoc,
+                           EndLoc,
                            /*FromDecl=*/nullptr,
                            /*Context=*/nullptr,
                            /*Specifier=*/nullptr,
                            /*IgnorePrefixQualifers=*/true};
         RenameInfos.push_back(Info);
       }
+    }
     return true;
   }
 
   bool VisitDeclRefExpr(const DeclRefExpr *Expr) {
     const NamedDecl *Decl = Expr->getFoundDecl();
     // Get the underlying declaration of the shadow declaration introduced by a
     // using declaration.
     if (auto *UsingShadow = llvm::dyn_cast<UsingShadowDecl>(Decl)) {
       Decl = UsingShadow->getTargetDecl();
     }
 
-    auto BeginLoc = Expr->getLocStart();
+    auto StartLoc = Expr->getLocStart();
     auto EndLoc = Expr->getLocEnd();
     // In case of renaming an enum declaration, we have to explicitly handle
     // unscoped enum constants referenced in expressions (e.g.
     // "auto r = ns1::ns2::Green" where Green is an enum constant of an unscoped
     // enum decl "ns1::ns2::Color") as these enum constants cannot be caught by
     // TypeLoc.
     if (const auto *T = llvm::dyn_cast<EnumConstantDecl>(Decl)) {
       // FIXME: Handle the enum constant without prefix qualifiers (`a = Green`)
if (const auto *T = llvm::dyn_cast<EnumConstantDecl>(Decl)) {
       //    ns1::ns2::Green;
       //    ^      ^^
       // BeginLoc  |EndLoc of the qualifier
       //           new EndLoc
       EndLoc = Expr->getQualifierLoc().getEndLoc().getLocWithOffset(-1);
       assert(EndLoc.isValid() &&
              "The enum constant should have prefix qualifers.");
     }
-    if (isInUSRSet(Decl)) {
-      RenameInfo Info = {BeginLoc,
+    if (isInUSRSet(Decl) &&
+        IsValidEditLoc(Context.getSourceManager(), StartLoc)) {
+      RenameInfo Info = {StartLoc,
                          EndLoc,
                          Decl,
                          getClosestAncestorDecl(*Expr),
                          Expr->getQualifier(),
                          /*IgnorePrefixQualifers=*/false};
       RenameInfos.push_back(Info);
     }
 
     return true;
   }
 
   bool VisitUsingDecl(const UsingDecl *Using) {
     for (const auto *UsingShadow : Using->shadows()) {
       if (isInUSRSet(UsingShadow->getTargetDecl())) {
         UsingDecls.push_back(Using);
         break;
       }
     }
     return true;
   }
 
   bool VisitNestedNameSpecifierLocations(NestedNameSpecifierLoc NestedLoc) {
     if (!NestedLoc.getNestedNameSpecifier()->getAsType())
       return true;
-    if (IsTypeAliasWhichWillBeRenamedElsewhere(NestedLoc.getTypeLoc()))
-      return true;
 
     if (const auto *TargetDecl =
             getSupportedDeclFromTypeLoc(NestedLoc.getTypeLoc())) {
       if (isInUSRSet(TargetDecl)) {
         RenameInfo Info = {NestedLoc.getBeginLoc(),
                            EndLocationForType(NestedLoc.getTypeLoc()),
                            TargetDecl,
                            getClosestAncestorDecl(NestedLoc),
                            NestedLoc.getNestedNameSpecifier()->getPrefix(),
                            /*IgnorePrefixQualifers=*/false};
         RenameInfos.push_back(Info);
       }
     }
     return true;
   }
 
   bool VisitTypeLoc(TypeLoc Loc) {
-    if (IsTypeAliasWhichWillBeRenamedElsewhere(Loc))
-      return true;
-
     auto Parents = Context.getParents(Loc);
     TypeLoc ParentTypeLoc;
     if (!Parents.empty()) {
       // Handle cases of nested name specificier locations.
       //
       // The VisitNestedNameSpecifierLoc interface is not impelmented in
       // RecursiveASTVisitor, we have to handle it explicitly.
       if (const auto *NSL = Parents[0].get<NestedNameSpecifierLoc>()) {
if (const auto *TargetDecl = getSupportedDeclFromTypeLoc(Loc)) {
         //   ElaboratedType 0x33b9390 'a::Foo' sugar
         //   `-RecordType 0x338fef0 'class a::Foo'
         //     `-CXXRecord 0x338fe58 'Foo'
         //
         // Skip if this is an inner typeLoc.
         if (!ParentTypeLoc.isNull() &&
             isInUSRSet(getSupportedDeclFromTypeLoc(ParentTypeLoc)))
           return true;
-        RenameInfo Info = {StartLocationForType(Loc),
-                           EndLocationForType(Loc),
+
+        auto StartLoc = StartLocationForType(Loc);
+        auto EndLoc = EndLocationForType(Loc);
+        if (IsValidEditLoc(Context.getSourceManager(), StartLoc)) {
+          RenameInfo Info = {StartLoc,
+                             EndLoc,
                              TargetDecl,
                              getClosestAncestorDecl(Loc),
                              GetNestedNameForType(Loc),
                              /*IgnorePrefixQualifers=*/false};
           RenameInfos.push_back(Info);
+        }
         return true;
       }
     }
 
     // Handle specific template class specialiation cases.
     if (const auto *TemplateSpecType =
             dyn_cast<TemplateSpecializationType>(Loc.getType())) {
       TypeLoc TargetLoc = Loc;
       if (!ParentTypeLoc.isNull()) {
         if (llvm::isa<ElaboratedType>(ParentTypeLoc.getType()))
           TargetLoc = ParentTypeLoc;
       }
 
       if (isInUSRSet(TemplateSpecType->getTemplateName().getAsTemplateDecl())) {
         TypeLoc TargetLoc = Loc;
         // FIXME: Find a better way to handle this case.
         // For the qualified template class specification type like
         // "ns::Foo<int>" in "ns::Foo<int>& f();", we want the parent typeLoc
         // (ElaboratedType) of the TemplateSpecializationType in order to
         // catch the prefix qualifiers "ns::".
         if (!ParentTypeLoc.isNull() &&
             llvm::isa<ElaboratedType>(ParentTypeLoc.getType()))
           TargetLoc = ParentTypeLoc;
+
+        auto StartLoc = StartLocationForType(TargetLoc);
+        auto EndLoc = EndLocationForType(TargetLoc);
+        if (IsValidEditLoc(Context.getSourceManager(), StartLoc)) {
           RenameInfo Info = {
-            StartLocationForType(TargetLoc),
-            EndLocationForType(TargetLoc),
+              StartLoc,
+              EndLoc,
               TemplateSpecType->getTemplateName().getAsTemplateDecl(),
               getClosestAncestorDecl(
                   ast_type_traits::DynTypedNode::create(TargetLoc)),
               GetNestedNameForType(TargetLoc),
               /*IgnorePrefixQualifers=*/false};
           RenameInfos.push_back(Info);
         }
       }
+    }
     return true;
   }
 
   // Returns a list of RenameInfo.
   const std::vector<RenameInfo> &getRenameInfos() const { return RenameInfos; }
 
   // Returns a list of using declarations which are needed to update.
   const std::vector<const UsingDecl *> &getUsingDecls() const {
     return UsingDecls;
   }
 
 private:
-  // FIXME: This method may not be suitable for renaming other types like alias
-  // types. Need to figure out a way to handle it.
-  bool IsTypeAliasWhichWillBeRenamedElsewhere(TypeLoc TL) const {
-    while (!TL.isNull()) {
-      // SubstTemplateTypeParm is the TypeLocation class for a substituted type
-      // inside a template expansion so we ignore these.  For example:
-      //
-      // template<typename T> struct S {
-      //   T t;  // <-- this T becomes a TypeLoc(int) with class
-      //         //     SubstTemplateTypeParm when S<int> is instantiated
-      // }
-      if (TL.getTypeLocClass() == TypeLoc::SubstTemplateTypeParm)
-        return true;
-
-      // Typedef is the TypeLocation class for a type which is a typedef to the
-      // type we want to replace.  We ignore the use of the typedef as we will
-      // replace the definition of it.  For example:
-      //
-      // typedef int T;
-      // T a;  // <---  This T is a TypeLoc(int) with class Typedef.
-      if (TL.getTypeLocClass() == TypeLoc::Typedef)
-        return true;
-      TL = TL.getNextTypeLoc();
-    }
-    return false;
-  }
-
   // Get the supported declaration from a given typeLoc. If the declaration type
   // is not supported, returns nullptr.
-  //
-  // FIXME: support more types, e.g. type alias.
   const NamedDecl *getSupportedDeclFromTypeLoc(TypeLoc Loc) {
+    if (const auto* TT = Loc.getType()->getAs<clang::TypedefType>())
+      return TT->getDecl();
     if (const auto *RD = Loc.getType()->getAsCXXRecordDecl())
       return RD;
     if (const auto *ED =
             llvm::dyn_cast_or_null<EnumDecl>(Loc.getType()->getAsTagDecl()))
       return ED;
     return nullptr;
   }
 

cfe/trunk/unittests/Rename/CMakeLists.txt

 set(LLVM_LINK_COMPONENTS
   support
   )
 
 # We'd like clang/unittests/Tooling/RewriterTestContext.h in the test.
 include_directories(${CLANG_SOURCE_DIR})
 
 add_clang_unittest(ClangRenameTests
   RenameClassTest.cpp
   RenameEnumTest.cpp
+  RenameAliasTest.cpp
   RenameFunctionTest.cpp
   )
 
 target_link_libraries(ClangRenameTests
   clangAST
   clangASTMatchers
   clangBasic
   clangFormat
   clangFrontend
   clangRewrite
   clangTooling
   clangToolingCore
   clangToolingRefactor
   )

cfe/trunk/unittests/Rename/RenameAliasTest.cpp

+//===-- RenameAliasTest.cpp - unit tests for renaming alias ---------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "ClangRenameTest.h"
+
+namespace clang {
+namespace clang_rename {
+namespace test {
+namespace {
+
+class RenameAliasTest : public ClangRenameTest {
+public:
+  RenameAliasTest() {
+    AppendToHeader(R"(
+        #define MACRO(x) x
+        namespace some_ns {
+        class A {
+         public:
+          void foo() {}
+          struct Nested {
+           enum NestedEnum {
+             E1, E2,
+           };
+          };
+        };
+        } // namespace some_ns
+        namespace a {
+        typedef some_ns::A TA;
+        using UA = some_ns::A;
+        } // namespace a
+        namespace b {
+        typedef some_ns::A TA;
+        using UA = some_ns::A;
+        }
+        template <typename T> class ptr {};
+        template <typename T>
+
+        using TPtr = ptr<int>;
+    )");
+  }
+};
+
+INSTANTIATE_TEST_CASE_P(
+    RenameAliasTests, RenameAliasTest,
+    testing::ValuesIn(std::vector<Case>({
+        // basic functions
+        {"void f(a::TA a1) {}", "void f(b::TB a1) {}", "a::TA", "b::TB"},
+        {"void f(a::UA a1) {}", "void f(b::UB a1) {}", "a::UA", "b::UB"},
+        {"void f(a::TA* a1) {}", "void f(b::TB* a1) {}", "a::TA", "b::TB"},
+        {"void f(a::TA** a1) {}", "void f(b::TB** a1) {}", "a::TA", "b::TB"},
+        {"a::TA f() { return a::TA(); }", "b::TB f() { return b::TB(); }",
+         "a::TA", "b::TB"},
+        {"a::TA f() { return a::UA(); }", "b::TB f() { return a::UA(); }",
+         "a::TA", "b::TB"},
+        {"a::TA f() { return a::UA(); }", "a::TA f() { return b::UB(); }",
+         "a::UA", "b::UB"},
+        {"void f() { a::TA a; }", "void f() { b::TB a; }", "a::TA", "b::TB"},
+        {"void f(const a::TA& a1) {}", "void f(const b::TB& a1) {}", "a::TA",
+         "b::TB"},
+        {"void f(const a::UA& a1) {}", "void f(const b::UB& a1) {}", "a::UA",
+         "b::UB"},
+        {"void f(const a::TA* a1) {}", "void f(const b::TB* a1) {}", "a::TA",
+         "b::TB"},
+        {"namespace a { void f(TA a1) {} }",
+         "namespace a { void f(b::TB a1) {} }", "a::TA", "b::TB"},
+        {"void f(MACRO(a::TA) a1) {}", "void f(MACRO(b::TB) a1) {}", "a::TA",
+         "b::TB"},
+        {"void f(MACRO(a::TA a1)) {}", "void f(MACRO(b::TB a1)) {}", "a::TA",
+         "b::TB"},
+
+        // shorten/add namespace.
+        {"namespace b { void f(a::UA a1) {} }",
+         "namespace b {void f(UB a1) {} }", "a::UA", "b::UB"},
+        {"namespace a { void f(UA a1) {} }",
+         "namespace a {void f(b::UB a1) {} }", "a::UA", "b::UB"},
+
+        // use namespace and typedefs
+        {"struct S { using T = a::TA; T a_; };",
+         "struct S { using T = b::TB; T a_; };", "a::TA", "b::TB"},
+        {"using T = a::TA; T gA;", "using T = b::TB; T gA;", "a::TA", "b::TB"},
+        {"using T = a::UA; T gA;", "using T = b::UB; T gA;", "a::UA", "b::UB"},
+        {"typedef a::TA T; T gA;", "typedef b::TB T; T gA;", "a::TA", "b::TB"},
+        {"typedef a::UA T; T gA;", "typedef b::UB T; T gA;", "a::UA", "b::UB"},
+        {"typedef MACRO(a::TA) T; T gA;", "typedef MACRO(b::TB) T; T gA;",
+         "a::TA", "b::TB"},
+
+        // types in using shadows.
+        {"using a::TA; TA gA;", "using b::TB; b::TB gA;", "a::TA", "b::TB"},
+        {"using a::UA; UA gA;", "using b::UB; b::UB gA;", "a::UA", "b::UB"},
+
+        // struct members and other oddities
+        {"struct S : public a::TA {};", "struct S : public b::TB {};", "a::TA",
+         "b::TB"},
+        {"struct S : public a::UA {};", "struct S : public b::UB {};", "a::UA",
+         "b::UB"},
+        {"struct F { void f(a::TA a1) {} };",
+         "struct F { void f(b::TB a1) {} };", "a::TA", "b::TB"},
+        {"struct F { a::TA a_; };", "struct F { b::TB a_; };", "a::TA",
+         "b::TB"},
+        {"struct F { ptr<a::TA> a_; };", "struct F { ptr<b::TB> a_; };",
+         "a::TA", "b::TB"},
+        {"struct F { ptr<a::UA> a_; };", "struct F { ptr<b::UB> a_; };",
+         "a::UA", "b::UB"},
+
+        // types in nested name specifiers
+        {"void f() { a::TA::Nested ne; }", "void f() { b::TB::Nested ne; }",
+         "a::TA", "b::TB"},
+        {"void f() { a::UA::Nested ne; }", "void f() { b::UB::Nested ne; }",
+         "a::UA", "b::UB"},
+        {"void f() { a::TA::Nested::NestedEnum e; }",
+         "void f() { b::TB::Nested::NestedEnum e; }", "a::TA", "b::TB"},
+        {"void f() { auto e = a::TA::Nested::NestedEnum::E1; }",
+         "void f() { auto e = b::TB::Nested::NestedEnum::E1; }", "a::TA",
+         "b::TB"},
+        {"void f() { auto e = a::TA::Nested::E1; }",
+         "void f() { auto e = b::TB::Nested::E1; }", "a::TA", "b::TB"},
+
+        // templates
+        {"template <typename T> struct Foo { T t; }; void f() { Foo<a::TA> "
+         "foo; }",
+         "template <typename T> struct Foo { T t; }; void f() { Foo<b::TB> "
+         "foo; }",
+         "a::TA", "b::TB"},
+        {"template <typename T> struct Foo { a::TA a; };",
+         "template <typename T> struct Foo { b::TB a; };", "a::TA", "b::TB"},
+        {"template <typename T> void f(T t) {} void g() { f<a::TA>(a::TA()); }",
+         "template <typename T> void f(T t) {} void g() { f<b::TB>(b::TB()); }",
+         "a::TA", "b::TB"},
+        {"template <typename T> void f(T t) {} void g() { f<a::UA>(a::UA()); }",
+         "template <typename T> void f(T t) {} void g() { f<b::UB>(b::UB()); }",
+         "a::UA", "b::UB"},
+        {"template <typename T> int f() { return 1; } template <> int "
+         "f<a::TA>() { return 2; } int g() { return f<a::TA>(); }",
+         "template <typename T> int f() { return 1; } template <> int "
+         "f<b::TB>() { return 2; } int g() { return f<b::TB>(); }",
+         "a::TA", "b::TB"},
+        {"struct Foo { template <typename T> T foo(); }; void g() { Foo f;  "
+         "auto a = f.template foo<a::TA>(); }",
+         "struct Foo { template <typename T> T foo(); }; void g() { Foo f;  "
+         "auto a = f.template foo<b::TB>(); }",
+         "a::TA", "b::TB"},
+        {"struct Foo { template <typename T> T foo(); }; void g() { Foo f;  "
+         "auto a = f.template foo<a::UA>(); }",
+         "struct Foo { template <typename T> T foo(); }; void g() { Foo f;  "
+         "auto a = f.template foo<b::UB>(); }",
+         "a::UA", "b::UB"},
+
+        // The following two templates are distilled from regressions found in
+        // unique_ptr<> and type_traits.h
+        {"template <typename T> struct outer { typedef T type; type Baz(); }; "
+         "outer<a::TA> g_A;",
+         "template <typename T> struct outer { typedef T type; type Baz(); }; "
+         "outer<b::TB> g_A;",
+         "a::TA", "b::TB"},
+        {"template <typename T> struct nested { typedef T type; }; template "
+         "<typename T> struct outer { typename nested<T>::type Foo(); }; "
+         "outer<a::TA> g_A;",
+         "template <typename T> struct nested { typedef T type; }; template "
+         "<typename T> struct outer { typename nested<T>::type Foo(); }; "
+         "outer<b::TB> g_A;",
+         "a::TA", "b::TB"},
+
+        // macros
+        {"#define FOO(T, t) T t\nvoid f() { FOO(a::TA, a1); FOO(a::TA, a2); }",
+         "#define FOO(T, t) T t\nvoid f() { FOO(b::TB, a1); FOO(b::TB, a2); }",
+         "a::TA", "b::TB"},
+        {"#define FOO(n) a::TA n\nvoid f() { FOO(a1); FOO(a2); }",
+         "#define FOO(n) b::TB n\nvoid f() { FOO(a1); FOO(a2); }", "a::TA",
+         "b::TB"},
+        {"#define FOO(n) a::UA n\nvoid f() { FOO(a1); FOO(a2); }",
+         "#define FOO(n) b::UB n\nvoid f() { FOO(a1); FOO(a2); }", "a::UA",
+         "b::UB"},
+
+        // Pointer to member functions
+        {"auto gA = &a::TA::foo;", "auto gA = &b::TB::foo;", "a::TA", "b::TB"},
+        {"using a::TA; auto gA = &TA::foo;",
+         "using b::TB; auto gA = &b::TB::foo;", "a::TA", "b::TB"},
+        {"typedef a::TA T; auto gA = &T::foo;",
+         "typedef b::TB T; auto gA = &T::foo;", "a::TA", "b::TB"},
+        {"auto gA = &MACRO(a::TA)::foo;", "auto gA = &MACRO(b::TB)::foo;",
+         "a::TA", "b::TB"},
+
+        // templated using alias.
+        {"void f(TPtr<int> p) {}", "void f(NewTPtr<int> p) {}", "TPtr",
+         "NewTPtr"},
+        {"void f(::TPtr<int> p) {}", "void f(::NewTPtr<int> p) {}", "TPtr",
+         "NewTPtr"},
+    })), );
+
+TEST_P(RenameAliasTest, RenameAlias) {
+  auto Param = GetParam();
+  assert(!Param.OldName.empty());
+  assert(!Param.NewName.empty());
+  std::string Actual =
+      runClangRenameOnCode(Param.Before, Param.OldName, Param.NewName);
+  CompareSnippets(Param.After, Actual);
+}
+
+TEST_F(RenameAliasTest, RenameTypedefDefinitions) {
+  std::string Before = R"(
+    class X {};
+    typedef X TOld;
+    )";
+  std::string Expected = R"(
+    class X {};
+    typedef X TNew;
+    )";
+  std::string After = runClangRenameOnCode(Before, "TOld", "TNew");
+  CompareSnippets(Expected, After);
+}
+
+TEST_F(RenameAliasTest, RenameUsingAliasDefinitions) {
+  std::string Before = R"(
+    class X {};
+    using UOld = X;
+    )";
+  std::string Expected = R"(
+    class X {};
+    using UNew = X;
+    )";
+  std::string After = runClangRenameOnCode(Before, "UOld", "UNew");
+  CompareSnippets(Expected, After);
+}
+
+TEST_F(RenameAliasTest, RenameTemplatedAliasDefinitions) {
+  std::string Before = R"(
+    template <typename T>
+    class X { T t; };
+
+    template <typename T>
+    using Old = X<T>;
+    )";
+  std::string Expected = R"(
+    template <typename T>
+    class X { T t; };
+
+    template <typename T>
+    using New = X<T>;
+    )";
+  std::string After = runClangRenameOnCode(Before, "Old", "New");
+  CompareSnippets(Expected, After);
+}
+
+TEST_F(RenameAliasTest, RenameAliasesInNamespaces) {
+  std::string Before = R"(
+    namespace x { class X {}; }
+    namespace ns {
+    using UOld = x::X;
+    }
+    )";
+  std::string Expected = R"(
+    namespace x { class X {}; }
+    namespace ns {
+    using UNew = x::X;
+    }
+    )";
+  std::string After = runClangRenameOnCode(Before, "ns::UOld", "ns::UNew");
+  CompareSnippets(Expected, After);
+}
+
+TEST_F(RenameAliasTest, AliasesInMacros) {
+  std::string Before = R"(
+    namespace x { class Old {}; }
+    namespace ns {
+    #define REF(alias) alias alias_var;
+
+    #define ALIAS(old) \
+      using old##Alias = x::old; \
+      REF(old##Alias);
+
+    ALIAS(Old);
+
+    OldAlias old_alias;
+    }
+    )";
+  std::string Expected = R"(
+    namespace x { class Old {}; }
+    namespace ns {
+    #define REF(alias) alias alias_var;
+
+    #define ALIAS(old) \
+      using old##Alias = x::old; \
+      REF(old##Alias);
+
+    ALIAS(Old);
+
+    NewAlias old_alias;
+    }
+    )";
+  std::string After =
+      runClangRenameOnCode(Before, "ns::OldAlias", "ns::NewAlias");
+  CompareSnippets(Expected, After);
+}
+
+} // anonymous namespace
+} // namespace test
+} // namespace clang_rename
+} // namesdpace clang