From 4ae2381430013b64a3c013c62bf038f3fa659f66 Mon Sep 17 00:00:00 2001
From: Ilya Biryukov <ibiryukov@google.com>
Date: Fri, 27 Sep 2019 17:55:46 +0000
Subject: [PATCH] [clangd] Fix template type aliases in findExplicitReference

Reviewers: kadircet

Reviewed By: kadircet

Subscribers: MaskRay, jkorous, arphaman, usaxena95, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D68124

llvm-svn: 373104
---
 clang-tools-extra/clangd/FindTarget.cpp            | 25 +++++++++++++++-------
 .../clangd/unittests/FindTargetTests.cpp           | 24 ++++++++++-----------
 2 files changed, 28 insertions(+), 21 deletions(-)

diff --git a/clang-tools-extra/clangd/FindTarget.cpp b/clang-tools-extra/clangd/FindTarget.cpp
index 6bbaa5e..08bdf97 100644
--- a/clang-tools-extra/clangd/FindTarget.cpp
+++ b/clang-tools-extra/clangd/FindTarget.cpp
@@ -477,13 +477,6 @@ Optional<ReferenceLoc> refInTypeLoc(TypeLoc L) {
       Ref->Qualifier = L.getQualifierLoc();
     }
 
-    void VisitDeducedTemplateSpecializationTypeLoc(
-        DeducedTemplateSpecializationTypeLoc L) {
-      Ref = ReferenceLoc{
-          NestedNameSpecifierLoc(), L.getNameLoc(),
-          explicitReferenceTargets(DynTypedNode::create(L.getType()))};
-    }
-
     void VisitTagTypeLoc(TagTypeLoc L) {
       Ref =
           ReferenceLoc{NestedNameSpecifierLoc(), L.getNameLoc(), {L.getDecl()}};
@@ -495,9 +488,25 @@ Optional<ReferenceLoc> refInTypeLoc(TypeLoc L) {
     }
 
     void VisitTemplateSpecializationTypeLoc(TemplateSpecializationTypeLoc L) {
+      // We must ensure template type aliases are included in results if they
+      // were written in the source code, e.g. in
+      //    template <class T> using valias = vector<T>;
+      //    ^valias<int> x;
+      // 'explicitReferenceTargets' will return:
+      //    1. valias with mask 'Alias'.
+      //    2. 'vector<int>' with mask 'Underlying'.
+      //  we want to return only #1 in this case.
       Ref = ReferenceLoc{
           NestedNameSpecifierLoc(), L.getTemplateNameLoc(),
-          explicitReferenceTargets(DynTypedNode::create(L.getType()))};
+          explicitReferenceTargets(DynTypedNode::create(L.getType()),
+                                   DeclRelation::Alias)};
+    }
+    void VisitDeducedTemplateSpecializationTypeLoc(
+        DeducedTemplateSpecializationTypeLoc L) {
+      Ref = ReferenceLoc{
+          NestedNameSpecifierLoc(), L.getNameLoc(),
+          explicitReferenceTargets(DynTypedNode::create(L.getType()),
+                                   DeclRelation::Alias)};
     }
 
     void VisitDependentTemplateSpecializationTypeLoc(
diff --git a/clang-tools-extra/clangd/unittests/FindTargetTests.cpp b/clang-tools-extra/clangd/unittests/FindTargetTests.cpp
index 32aa25a..91f78e3 100644
--- a/clang-tools-extra/clangd/unittests/FindTargetTests.cpp
+++ b/clang-tools-extra/clangd/unittests/FindTargetTests.cpp
@@ -615,20 +615,18 @@ TEST_F(FindExplicitReferencesTest, All) {
         )cpp",
            "0: targets = {vector<int>}\n"
            "1: targets = {vector<bool>}\n"},
-          // FIXME: Fix 'allTargetDecls' to return alias template and re-enable.
           // Template type aliases.
-          //   {R"cpp(
-          //   template <class T> struct vector { using value_type = T; };
-          //   template <> struct vector<bool> { using value_type = bool; };
-          //   template <class T> using valias = vector<T>;
-          //   void foo() {
-          //     $0^valias<int> vi;
-          //     $1^valias<bool> vb;
-          //   }
-          // )cpp",
-          //    "0: targets = {valias}\n"
-          //    "1: targets = {valias}\n"},
-
+          {R"cpp(
+            template <class T> struct vector { using value_type = T; };
+            template <> struct vector<bool> { using value_type = bool; };
+            template <class T> using valias = vector<T>;
+            void foo() {
+              $0^valias<int> vi;
+              $1^valias<bool> vb;
+            }
+          )cpp",
+           "0: targets = {valias}\n"
+           "1: targets = {valias}\n"},
           // MemberExpr should know their using declaration.
           {R"cpp(
             struct X { void func(int); }
-- 
2.7.4