3 files changed, 31 insertions, 5 deletions
diff --git a/Tests/ExportImport/Import/A/deps_iface.c b/Tests/ExportImport/Import/A/deps_iface.c
index e2d973c2f..afb1af01f 100644
--- a/Tests/ExportImport/Import/A/deps_iface.c
+++ b/Tests/ExportImport/Import/A/deps_iface.c
@@ -1,9 +1,4 @@
 
-#include "testLibIncludeRequired1.h"
-#include "testLibIncludeRequired2.h"
-#include "testLibIncludeRequired6.h"
-#include "testLibIncludeRequired7.h"
-
 #include "installIncludesTest.h"
 #include "installIncludesTest2.h"
 #include "installIncludesTest3.h"
@@ -12,6 +7,10 @@
 #include "installIncludesTest6.h"
 #include "installIncludesTest7.h"
 #include "installIncludesTest8.h"
+#include "testLibIncludeRequired1.h"
+#include "testLibIncludeRequired2.h"
+#include "testLibIncludeRequired6.h"
+#include "testLibIncludeRequired7.h"
 
 #ifndef testLibRequired_IFACE_DEFINE
 #  error Expected testLibRequired_IFACE_DEFINE
diff --git a/Tests/ExportImport/Import/Interface/CMakeLists.txt b/Tests/ExportImport/Import/Interface/CMakeLists.txt
index a07a5b3c4..ef666b1a7 100644
--- a/Tests/ExportImport/Import/Interface/CMakeLists.txt
+++ b/Tests/ExportImport/Import/Interface/CMakeLists.txt
@@ -98,6 +98,17 @@ set_property(TARGET exp::sharediface APPEND PROPERTY INTERFACE_LINK_LIBRARIES de
 add_executable(interfacetest_exp interfacetest.cpp)
 target_link_libraries(interfacetest_exp exp::sharediface)
 
+if(NOT CMAKE_OSX_ARCHITECTURES MATCHES "[;$]" OR CMAKE_GENERATOR STREQUAL "Xcode")
+  add_executable(pch_iface_test_bld pch_iface_test.cpp)
+  target_link_libraries(pch_iface_test_bld bld::pch_iface)
+  add_executable(pch_iface_test_exp pch_iface_test.cpp)
+  target_link_libraries(pch_iface_test_exp exp::pch_iface)
+  if(CMAKE_CXX_COMPILE_OPTIONS_USE_PCH)
+    target_compile_definitions(pch_iface_test_bld PRIVATE EXPECT_PCH)
+    target_compile_definitions(pch_iface_test_exp PRIVATE EXPECT_PCH)
+  endif()
+endif()
+
 do_try_compile(exp)
 
 foreach(ns exp bld)
diff --git a/Tests/ExportImport/Import/Interface/pch_iface_test.cpp b/Tests/ExportImport/Import/Interface/pch_iface_test.cpp
new file mode 100644
index 000000000..a18bbde23
--- /dev/null
+++ b/Tests/ExportImport/Import/Interface/pch_iface_test.cpp
@@ -0,0 +1,16 @@
+#ifdef EXPECT_PCH
+// Verify that pch/pch.h was included via '-include ...' or equivalent.
+#  ifndef PCH_PCH_H_INCLUDED
+#    error "Expected PCH_PCH_H_INCLUDED."
+#  endif
+#elif defined(__PGIC__) || defined(__ibmxl__) || defined(_CRAYC)
+// No PCH expected but these compilers define macros below.
+#elif defined(__GNUC__) || defined(__clang__) || defined(_INTEL_COMPILER) ||  \
+  defined(_MSC_VER)
+#  error "Expected EXPECT_PCH for this compiler."
+#endif
+
+int main()
+{
+  return 0;
+}