Add SYSTEMC_UNITY_BUILD CMake option and require CMake 3.16+

INSTALL.md

@@ -405,7 +405,7 @@ As an example, here is a minimal `CMakeLists.txt` to compile the `simple_perf`
 SystemC example as a stand-alone application:
 
       --- Start: CMakeLists.txt ---
-      cmake_minimum_required(VERSION 3.5)
+      cmake_minimum_required(VERSION 3.16)
       project(simple_perf CXX)
 
       set (CMAKE_PREFIX_PATH /opt/systemc)

cmake/run-example.cmake

@@ -38,7 +38,7 @@
 ###############################################################################
 
 
-cmake_minimum_required(VERSION 3.5...3.31)
+cmake_minimum_required(VERSION 3.16...3.31)
 
 if(NOT TEST_EXE)
   message(FATAL_ERROR "  Usage: cmake -DTEST_EXE=<executable> [-DTEST_INPUT=<input-file>] \\\n"

src/CMakeLists.txt

@@ -38,12 +38,14 @@
 #
 ###############################################################################
 
-cmake_minimum_required(VERSION 3.8...3.31)
+cmake_minimum_required(VERSION 3.16...3.31)
 
 ###############################################################################
 # Build rules for SystemC library
 ###############################################################################
 
+option(SYSTEMC_UNITY_BUILD "Enable unity build" OFF)
+
 function(add_systemc_library libName scBuildDefine)
 
     add_library(${libName} ${ARGN})
@@ -124,6 +126,14 @@ function(add_systemc_library libName scBuildDefine)
         SOVERSION ${SystemCLanguage_SOVERSION}
         )
 
+    if(SYSTEMC_UNITY_BUILD)
+      message(STATUS "Enable SystemC unity build")
+      set_target_properties(${libName} PROPERTIES UNITY_BUILD ON)
+      set_source_files_properties(sysc/utils/sc_utils_ids.cpp PROPERTIES SKIP_UNITY_BUILD_INCLUSION ON)
+    else()
+      message(STATUS "Disable SystemC unity build")
+    endif()
+
 endfunction(add_systemc_library)
 
 set(SYSTEMC_CORE_SRC

src/sysc/datatypes/fx/sc_fxnum.cpp

@@ -664,7 +664,7 @@ to_string( const scfx_ieee_double&,
 	   sc_numrep,
 	   int,
 	   sc_fmt,
-	   const scfx_params* = 0 );
+	   const scfx_params*);
 
 
 // explicit conversion to character string