From 37340798ccb00b9c3a53e8a5f1b6430e85870338 Mon Sep 17 00:00:00 2001
From: Zahira Ammarguellat <zahira.ammarguellat@intel.com>
Date: Fri, 6 Nov 2020 06:38:22 -0800
Subject: [PATCH] Argument dependent lookup with class argument is recursing
 into base classes that haven't been instantiated. This is generating an
 assertion in DeclTemplate.h. Fix for Bug25668.

---
 clang/lib/Sema/SemaLookup.cpp                 |  2 ++
 clang/lib/Sema/SemaOpenMP.cpp                 |  1 +
 clang/test/OpenMP/template-specialization.cpp | 16 ++++++++++++++++
 3 files changed, 19 insertions(+)
 create mode 100644 clang/test/OpenMP/template-specialization.cpp

diff --git a/clang/lib/Sema/SemaLookup.cpp b/clang/lib/Sema/SemaLookup.cpp
index 16dd8f5..34065a5 100644
--- a/clang/lib/Sema/SemaLookup.cpp
+++ b/clang/lib/Sema/SemaLookup.cpp
@@ -2576,6 +2576,8 @@ namespace {
 
     bool addClassTransitive(CXXRecordDecl *RD) {
       Classes.insert(RD);
+      if (InstantiationLoc.isInvalid())
+        InstantiationLoc = RD->getLocation();
       return ClassesTransitive.insert(RD);
     }
 
diff --git a/clang/lib/Sema/SemaOpenMP.cpp b/clang/lib/Sema/SemaOpenMP.cpp
index 63ea297..dece57b 100644
--- a/clang/lib/Sema/SemaOpenMP.cpp
+++ b/clang/lib/Sema/SemaOpenMP.cpp
@@ -17549,6 +17549,7 @@ static void checkMappableExpressionList(
     auto &DeclNames = SemaRef.getASTContext().DeclarationNames;
     MapperId.setName(DeclNames.getIdentifier(
         &SemaRef.getASTContext().Idents.get("default")));
+    MapperId.setLoc(StartLoc);
   }
 
   // Iterators to find the current unresolved mapper expression.
diff --git a/clang/test/OpenMP/template-specialization.cpp b/clang/test/OpenMP/template-specialization.cpp
new file mode 100644
index 0000000..714fbf4
--- /dev/null
+++ b/clang/test/OpenMP/template-specialization.cpp
@@ -0,0 +1,16 @@
+// RUN: %clang_cc1 -verify -fopenmp -fsyntax-only %s
+
+// expected-no-diagnostics
+
+template <typename T>
+struct z {
+  static void aj() {
+    T f;
+#pragma omp target map(f)
+    ;
+  }
+};
+
+template <typename> class ar {};
+template <int> struct as {};
+template class z<ar<as<4>>>;
-- 
2.7.4