From 9fda8b1d4d4cbe0087dab8a14a0cff4fa52c92f2 Mon Sep 17 00:00:00 2001
From: Kai Germaschewski <kai.germaschewski@unh.edu>
Date: Sat, 26 Sep 2020 13:45:11 -0400
Subject: [PATCH] thrust: separate out determination of whether Thrust is
 top-level project

---
 CMakeLists.txt | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index ac8d15058..b1f4ae7e0 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -11,9 +11,17 @@ endif()
 
 project(Thrust NONE)
 
+# Determine whether Thrust is the top-level project or included into
+# another project via add_subdirectory()
+if ("${CMAKE_SOURCE_DIR}" STREQUAL "${CMAKE_CURRENT_LIST_DIR}")
+  set(THRUST_TOPLEVEL_PROJECT ON)
+else()
+  set(THRUST_TOPLEVEL_PROJECT OFF)
+endif()
+
 # Support adding Thrust to a parent project via add_subdirectory.
 # See examples/cmake/add_subdir/CMakeLists.txt for details.
-if (NOT "${CMAKE_SOURCE_DIR}" STREQUAL "${CMAKE_CURRENT_LIST_DIR}")
+if (NOT THRUST_TOPLEVEL_PROJECT)
   include(cmake/ThrustAddSubdir.cmake)
   return()
 endif()