Merge topic 'check_cxx_compiler_flag_no_normal_variable' into release-3.21

018d300ca0 Check*CompilerFlag: Do not set result as a normal variable too

Acked-by: Kitware Robot <kwrobot@kitware.com>
Merge-request: !6318

Modules/Internal/CheckCompilerFlag.cmake

diff --git a/Modules/Internal/CheckCompilerFlag.cmake b/Modules/Internal/CheckCompilerFlag.cmake
index 693e28b..f6a4cc9 100644
--- a/Modules/Internal/CheckCompilerFlag.cmake
+++ b/Modules/Internal/CheckCompilerFlag.cmake
@@ -78,7 +78,6 @@
   foreach(v IN LISTS _locale_vars)
     set(ENV{${v}} ${_locale_vars_saved_${v}})
   endforeach()
-  set(${_var} "${${_var}}" PARENT_SCOPE)
 endfunction ()
 
 cmake_policy(POP)

Tests/TryCompile/CMakeLists.txt

diff --git a/Tests/TryCompile/CMakeLists.txt b/Tests/TryCompile/CMakeLists.txt
index fa0549f..d0c413f 100644
--- a/Tests/TryCompile/CMakeLists.txt
+++ b/Tests/TryCompile/CMakeLists.txt
@@ -305,11 +305,21 @@
 include(CheckCCompilerFlag)
 CHECK_C_COMPILER_FLAG(${C_DD}-_this_is_not_a_flag_ C_BOGUS_FLAG)
 TEST_FAIL(C_BOGUS_FLAG "CHECK_C_COMPILER_FLAG() succeeded, but should have failed")
+unset(C_BOGUS_FLAG CACHE)
+if(DEFINED C_BOGUS_FLAG)
+  # Verify that CHECK_C_COMPILER_FLAG didn't construct a normal variable
+  message(SEND_ERROR "CHECK_C_COMPILER_FLAG shouldn't construct C_BOGUS_FLAG as a normal variable")
+endif()
 
 unset(CXX_BOGUS_FLAG CACHE)
 include(CheckCXXCompilerFlag)
 CHECK_CXX_COMPILER_FLAG(${CXX_DD}-_this_is_not_a_flag_ CXX_BOGUS_FLAG)
 TEST_FAIL(CXX_BOGUS_FLAG "CHECK_CXX_COMPILER_FLAG() succeeded, but should have failed")
+unset(CXX_BOGUS_FLAG CACHE)
+if(DEFINED CXX_BOGUS_FLAG)
+  # Verify that CHECK_C_COMPILER_FLAG didn't construct a normal variable
+  message(SEND_ERROR "CHECK_CXX_COMPILER_FLAG shouldn't construct CXX_BOGUS_FLAG as a normal variable")
+endif()
 
 if(CMAKE_C_COMPILER_ID STREQUAL "GNU")
   unset(C_STRICT_PROTOTYPES CACHE)