From d60bf4f15fd5b382a36fa85bb005c5a4bf390748 Mon Sep 17 00:00:00 2001
From: dpasukhi <dpasukhi@opencascade.com>
Date: Mon, 15 Dec 2025 13:06:56 +0000
Subject: [PATCH] Configuration - Parallel installing and improve catching
 cmake version

- Added macros for version-gated boolean options in CMake.
- Updated CMakeLists.txt to conditionally enable precompiled headers and parallel installation based on CMake version.
- Enhanced documentation for new build options in vardescr.cmake.
---
 CMakeLists.txt              | 28 +++++++++++++---------------
 adm/cmake/occt_macros.cmake | 17 +++++++++++++++++
 adm/cmake/vardescr.cmake    |  4 ++++
 3 files changed, 34 insertions(+), 15 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index e8e743430e4..4d21e4e1584 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -206,21 +206,23 @@ if (BUILD_FORCE_RelWithDebInfo)
   set (CMAKE_CONFIGURATION_TYPES Release Debug CACHE INTERNAL "" FORCE)
 endif()
 
-# option to enable or disable use of precompiled headers
-if (NOT DEFINED BUILD_USE_PCH)
-  set (BUILD_USE_PCH OFF CACHE BOOL "${BUILD_USE_PCH_DESCR}")
-endif()
+# Version-gated build options (enabled by default when CMake version is sufficient)
+OCCT_VERSION_GATED_OPTION (BUILD_USE_PCH "3.16" ON "${BUILD_USE_PCH_DESCR}")
+OCCT_VERSION_GATED_OPTION (BUILD_INCLUDE_SYMLINK "3.14" ON "${BUILD_INCLUDE_SYMLINK_DESCR}")
+OCCT_VERSION_GATED_OPTION (BUILD_INSTALL_PARALLEL "3.30" ON "${BUILD_INSTALL_PARALLEL_DESCR}")
 
-if (CMAKE_VERSION VERSION_LESS "3.16")
-  OCCT_CHECK_AND_UNSET (BUILD_USE_PCH)
-elseif (NOT BUILD_USE_PCH)
-  set (CMAKE_DISABLE_PRECOMPILE_HEADERS ON)
-else ()
+# Apply precompiled headers setting
+if (BUILD_USE_PCH)
   set (CMAKE_DISABLE_PRECOMPILE_HEADERS OFF)
+elseif (DEFINED BUILD_USE_PCH)
+  set (CMAKE_DISABLE_PRECOMPILE_HEADERS ON)
 endif()
 
-if (NOT DEFINED BUILD_INCLUDE_SYMLINK)
-  set (BUILD_INCLUDE_SYMLINK OFF CACHE BOOL "${BUILD_INCLUDE_SYMLINK_DESCR}")
+# Apply parallel installation setting
+if (BUILD_INSTALL_PARALLEL)
+  set_property (GLOBAL PROPERTY INSTALL_PARALLEL ON)
+elseif (DEFINED BUILD_INSTALL_PARALLEL)
+  set_property (GLOBAL PROPERTY INSTALL_PARALLEL OFF)
 endif()
 
 # Overview
@@ -237,10 +239,6 @@ if (NOT DEFINED INSTALL_DOC_RefMan)
   set (INSTALL_DOC_RefMan OFF CACHE BOOL "${INSTALL_DOC_RefMan_DESCR}")
 endif()
 
-if (CMAKE_VERSION VERSION_LESS "3.14")
-  OCCT_CHECK_AND_UNSET (BUILD_INCLUDE_SYMLINK)
-endif()
-
 # copy samples to install directory
 set (INSTALL_SAMPLES OFF CACHE BOOL "${INSTALL_SAMPLES_DESCR}")
 
diff --git a/adm/cmake/occt_macros.cmake b/adm/cmake/occt_macros.cmake
index 360a5306cf8..698f6a83c34 100644
--- a/adm/cmake/occt_macros.cmake
+++ b/adm/cmake/occt_macros.cmake
@@ -12,6 +12,23 @@ macro (OCCT_CHECK_AND_UNSET VARNAME)
   endif()
 endmacro()
 
+# Macro to define a version-gated boolean option.
+# If CMake version is sufficient, option defaults to DEFAULT_ON value.
+# If CMake version is too old, option is unset and unavailable.
+# VARNAME - variable name
+# MIN_VERSION - minimum CMake version required
+# DEFAULT_ON - default value when version is sufficient (ON/OFF)
+# DESCRIPTION - variable description
+macro (OCCT_VERSION_GATED_OPTION VARNAME MIN_VERSION DEFAULT_ON DESCRIPTION)
+  if (CMAKE_VERSION VERSION_LESS "${MIN_VERSION}")
+    OCCT_CHECK_AND_UNSET (${VARNAME})
+  else()
+    if (NOT DEFINED ${VARNAME})
+      set (${VARNAME} ${DEFAULT_ON} CACHE BOOL "${DESCRIPTION}")
+    endif()
+  endif()
+endmacro()
+
 macro (OCCT_CHECK_AND_UNSET_GROUP GROUPNAME)
   get_cmake_property(VARS VARIABLES)
   string (REGEX MATCHALL "(^|;)${GROUPNAME}[A-Za-z0-9_]*" GROUPNAME_VARS "${VARS}")
diff --git a/adm/cmake/vardescr.cmake b/adm/cmake/vardescr.cmake
index f874b18a00c..c7b4d3ed11f 100644
--- a/adm/cmake/vardescr.cmake
+++ b/adm/cmake/vardescr.cmake
@@ -49,6 +49,10 @@ set (BUILD_INCLUDE_SYMLINK_DESCR
 OFF - using a reference file with direct include to the origin,
 ON - symbolic link to the origin file are created")
 
+set (BUILD_INSTALL_PARALLEL_DESCR
+"Enable parallel installation (requires CMake 3.30+).
+When enabled, cmake --install can use -j option to install in parallel.")
+
 # install variables
 set (INSTALL_DIR_DESCR 
 "The place where built OCCT libraries, headers, test cases (INSTALL_TEST_CASES variable),