Merge branch 'backport-vs-lang-flags' into vs-lang-flags

3 files changed, 23 insertions, 0 deletions

diff --git a/Tests/SetLang/CMakeLists.txt b/Tests/SetLang/CMakeLists.txt
index af90f11..616421e 100644
--- a/Tests/SetLang/CMakeLists.txt
+++ b/Tests/SetLang/CMakeLists.txt
@@ -9,6 +9,13 @@ set_source_files_properties(foo.c bar.c PROPERTIES LANGUAGE CXX)
 target_link_libraries(SetLang foo)
 set_target_properties(SetLang PROPERTIES LINKER_LANGUAGE CXX)
 
+# VS generators historically tolerated target-wide -TP flags added
+# by project code, so cover that case to preserve the behavior.
+if(CMAKE_GENERATOR MATCHES "^Visual Studio" AND "x${CMAKE_C_COMPILER_ID}" STREQUAL "xMSVC")
+  add_library(stay stay_c.c stay_cxx.cxx)
+  set_property(TARGET stay PROPERTY COMPILE_OPTIONS "-TP")
+endif()
+
 if((CMAKE_C_COMPILER_ID MATCHES "(GNU|Clang|MSVC|Borland|Embarcadero|Intel|TI|XL)"))
   add_library(zoom zoom.zzz)
   set_source_files_properties(zoom.zzz PROPERTIES LANGUAGE CXX)
diff --git a/Tests/SetLang/stay_c.c b/Tests/SetLang/stay_c.c
new file mode 100644
index 0000000..70755f3
--- /dev/null
+++ b/Tests/SetLang/stay_c.c
@@ -0,0 +1,8 @@
+#ifdef __cplusplus
+#  error C source incorrectly compiled as C++
+#endif
+
+int stay_c(void)
+{
+  return 0;
+}
diff --git a/Tests/SetLang/stay_cxx.cxx b/Tests/SetLang/stay_cxx.cxx
new file mode 100644
index 0000000..e035260
--- /dev/null
+++ b/Tests/SetLang/stay_cxx.cxx
@@ -0,0 +1,8 @@
+#ifndef __cplusplus
+#  error C++ source incorrectly compiled as C
+#endif
+
+int stay_cxx()
+{
+  return 0;
+}