From ff469fb37fde6ac319321e36e53e16f3b92452e9 Mon Sep 17 00:00:00 2001
From: Laurent Montel <montel@kde.org>
Date: Mon, 14 Dec 2020 13:58:38 +0100
Subject: [PATCH] Allow to use UNITY build see
 https://cmake.org/cmake/help/latest/prop_tgt/UNITY_BUILD.html (Reduce compile
 time. Need cmake 3.16.0)

---
 CMakeLists.txt                      | 10 ++++++++++
 src/pimcommon/CMakeLists.txt        |  3 +++
 src/pimcommonakonadi/CMakeLists.txt |  4 ++++
 3 files changed, 17 insertions(+)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index eaff48e..8e04806 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -65,6 +65,16 @@ find_package(KF5GrantleeTheme ${GRANTLEETHEME_LIB_VERSION} CONFIG REQUIRED)
 
 find_package(KF5Purpose ${KF5_MIN_VERSION} CONFIG REQUIRED)
 
+option(USE_UNIFY_CMAKE_SUPPORT "Use UNIFY cmake support (speedup compile time)" FALSE)
+
+set(COMPILE_WITH_CMAKE_SUPPORT false)
+if (USE_UNIFY_CMAKE_SUPPORT)
+    if(${CMAKE_VERSION} VERSION_LESS "3.16.0")
+        message(STATUS "CMAKE version is less than 3.16.0 . We can't use cmake unify build support")
+    else()
+        set(COMPILE_WITH_CMAKE_SUPPORT true)
+    endif()
+endif()
 
 option(BUILD_DESIGNERPLUGIN "Build plugin for Qt Designer" ON)
 add_feature_info(DESIGNERPLUGIN ${BUILD_DESIGNERPLUGIN} "Build plugin for Qt Designer")
diff --git a/src/pimcommon/CMakeLists.txt b/src/pimcommon/CMakeLists.txt
index f1d9bc1..f7620af 100644
--- a/src/pimcommon/CMakeLists.txt
+++ b/src/pimcommon/CMakeLists.txt
@@ -165,6 +165,9 @@ kconfig_add_kcfg_files(libpimcommon_SRCS
     )
 
 add_library(KF5PimCommon ${libpimcommon_SRCS})
+if (COMPILE_WITH_CMAKE_SUPPORT)
+    set_target_properties(KF5PimCommon PROPERTIES UNITY_BUILD ON)
+endif()
 generate_export_header(KF5PimCommon BASE_NAME pimcommon)
 add_library(KF5::PimCommon ALIAS KF5PimCommon)
 
diff --git a/src/pimcommonakonadi/CMakeLists.txt b/src/pimcommonakonadi/CMakeLists.txt
index b5078ca..dc31a40 100644
--- a/src/pimcommonakonadi/CMakeLists.txt
+++ b/src/pimcommonakonadi/CMakeLists.txt
@@ -140,6 +140,10 @@ ecm_qt_declare_logging_category(libpimcommonakonadi_SRCS HEADER pimcommonakonadi
 
 
 add_library(KF5PimCommonAkonadi ${libpimcommonakonadi_SRCS})
+if (COMPILE_WITH_CMAKE_SUPPORT)
+    set_target_properties(KF5PimCommonAkonadi PROPERTIES UNITY_BUILD ON)
+endif()
+
 generate_export_header(KF5PimCommonAkonadi BASE_NAME pimcommonakonadi)
 add_library(KF5::PimCommonAkonadi ALIAS KF5PimCommonAkonadi)
 
-- 
GitLab