STL Support: introduce dedicated configuration file

.clang-format

@@ -20,6 +20,8 @@ SortUsingDeclarations: false
 SpaceAfterTemplateKeyword: true
 IncludeBlocks: Regroup
 IncludeCategories:
+  - Regex:           '^[<"]cmSTL\.hxx'
+    Priority:        -2
   - Regex:           '^[<"]cmConfigure\.h'
     Priority:        -1
   - Regex:           '^<queue>'

CMakeLists.txt

@@ -108,6 +108,11 @@ if(NOT CMake_TEST_EXTERNAL_CMAKE)
   endif()
 endif()
 
+# Inform STL library header wrappers whether to use system versions.
+configure_file(${CMake_SOURCE_DIR}/Utilities/std/cmSTL.hxx.in
+  ${CMake_BINARY_DIR}/Utilities/cmSTL.hxx
+  @ONLY)
+
 # set the internal encoding of CMake to UTF-8
 set(KWSYS_ENCODING_DEFAULT_CODEPAGE CP_UTF8)
 

Source/cmConfigure.cmake.h.in

@@ -19,7 +19,6 @@
 #cmakedefine HAVE_UNSETENV
 #cmakedefine CMAKE_USE_ELF_PARSER
 #cmakedefine CMAKE_USE_MACH_PARSER
-#cmakedefine CMake_HAVE_CXX_MAKE_UNIQUE
 #define CMake_DEFAULT_RECURSION_LIMIT @CMake_DEFAULT_RECURSION_LIMIT@
 #define CMAKE_BIN_DIR "/@CMAKE_BIN_DIR@"
 #define CMAKE_DATA_DIR "/@CMAKE_DATA_DIR@"

Utilities/std/cm/memory

@@ -6,7 +6,10 @@
 #ifndef cm_memory
 #define cm_memory
 
+#include "cmSTL.hxx" // IWYU pragma: keep
+
 #include <memory> // IWYU pragma: export
+
 #if !defined(CMake_HAVE_CXX_MAKE_UNIQUE)
 #  include <cstddef>
 #  include <type_traits>

Utilities/std/cmSTL.hxx.in

@@ -0,0 +1,9 @@
+/* Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
+   file Copyright.txt or https://cmake.org/licensing for details.  */
+#ifndef cmSTL_hxx
+#define cmSTL_hxx
+
+/* Whether CMake is using its own STL implementation.  */
+#cmakedefine CMake_HAVE_CXX_MAKE_UNIQUE
+
+#endif

bootstrap

@@ -1272,6 +1272,9 @@ for feature in ${cmake_cxx_features}; do
   fi
 done
 
+cmake_generate_file "${cmake_bootstrap_dir}/cmSTL.hxx" ""
+
+
 #-----------------------------------------------------------------------------
 # Test Make