4 files changed, 26 insertions, 3 deletions
diff --git a/clang/lib/Index/IndexingContext.cpp b/clang/lib/Index/IndexingContext.cpp
index 6c09ac7c09a..80d851b43d7 100644
--- a/clang/lib/Index/IndexingContext.cpp
+++ b/clang/lib/Index/IndexingContext.cpp
@@ -350,6 +350,9 @@ bool IndexingContext::handleDeclOccurrence(const Decl *D, SourceLocation Loc,
     }
   }
 
+  if (!OrigD)
+    OrigD = D;
+
   if (isTemplateImplicitInstantiation(D)) {
     if (!IsRef)
       return true;
@@ -359,9 +362,6 @@ bool IndexingContext::handleDeclOccurrence(const Decl *D, SourceLocation Loc,
     assert(!isTemplateImplicitInstantiation(D));
   }
 
-  if (!OrigD)
-    OrigD = D;
-
   if (IsRef)
     Roles |= (unsigned)SymbolRole::Reference;
   else if (isDeclADefinition(OrigD, ContainerDC, *Ctx))
diff --git a/clang/test/Index/index-template-specialization.cpp b/clang/test/Index/index-template-specialization.cpp
new file mode 100644
index 00000000000..d11754113c4
--- /dev/null
+++ b/clang/test/Index/index-template-specialization.cpp
@@ -0,0 +1,19 @@
+template <typename T>
+class Foo {
+public:
+  void f(T t) {}
+};
+
+void g() {
+  Foo<int> foo;
+  foo.f(0);
+}
+
+// FIXME: if c-index-test uses OrigD for symbol info, refererences below should
+// refer to template specialization decls.
+// RUN: env CINDEXTEST_INDEXIMPLICITTEMPLATEINSTANTIATIONS=1 c-index-test -index-file %s | FileCheck %s
+// CHECK: [indexDeclaration]: kind: c++-class-template | name: Foo
+// CHECK-NEXT: [indexDeclaration]: kind: c++-instance-method | name: f
+// CHECK-NEXT: [indexDeclaration]: kind: function | name: g
+// CHECK-NEXT: [indexEntityReference]: kind: c++-class-template | name: Foo | USR: c:@ST>1#T@Foo
+// CHECK-NEXT: [indexEntityReference]: kind: c++-instance-method | name: f | USR: c:@ST>1#T@Foo@F@f#t0.0#
diff --git a/clang/tools/c-index-test/c-index-test.c b/clang/tools/c-index-test/c-index-test.c
index dd1652e32c0..70ab11866ed 100644
--- a/clang/tools/c-index-test/c-index-test.c
+++ b/clang/tools/c-index-test/c-index-test.c
@@ -3652,6 +3652,8 @@ static unsigned getIndexOptions(void) {
     index_opts |= CXIndexOpt_IndexFunctionLocalSymbols;
   if (!getenv("CINDEXTEST_DISABLE_SKIPPARSEDBODIES"))
     index_opts |= CXIndexOpt_SkipParsedBodiesInSession;
+  if (getenv("CINDEXTEST_INDEXIMPLICITTEMPLATEINSTANTIATIONS"))
+    index_opts |= CXIndexOpt_IndexImplicitTemplateInstantiations;
 
   return index_opts;
 }
diff --git a/clang/tools/libclang/Indexing.cpp b/clang/tools/libclang/Indexing.cpp
index 545edfbef4b..4da046b2823 100644
--- a/clang/tools/libclang/Indexing.cpp
+++ b/clang/tools/libclang/Indexing.cpp
@@ -402,6 +402,8 @@ static IndexingOptions getIndexingOptionsFromCXOptions(unsigned index_options) {
   IndexingOptions IdxOpts;
   if (index_options & CXIndexOpt_IndexFunctionLocalSymbols)
     IdxOpts.IndexFunctionLocals = true;
+  if (index_options & CXIndexOpt_IndexImplicitTemplateInstantiations)
+    IdxOpts.IndexImplicitInstantiation = true;
   return IdxOpts;
 }