Adds option ("-gs") to generate git submodule downloading/checking code to the root cmake file

src/main.cpp

@@ -44,6 +44,7 @@ int main(int argc, char** argv)
 	argParser.AddArg(ArgDesc("-a", true, 1, "Add library projects, separated by ',' (ex: -a first,second,third)"));
 	argParser.AddArg(ArgDesc("-x", true, 1, "Add executable submodule projects, separated by ',' (ex: -x first,second,third)"));
 	argParser.AddArg(ArgDesc("-r", true, 0, "Remove the root project executable"));
+	argParser.AddArg(ArgDesc("-gs", true, 0, "Add git subsystem updating to the main cmake file."));
 
     bool result = argParser.Parse();
 
@@ -223,7 +224,7 @@ int main(int argc, char** argv)
     ofs << "\nset(CMAKE_CXX_STANDARD " << cversion << ")";
     ofs << "\nset(CMAKE_CXX_STANDARD_REQUIRED True)";
 
-    ofs << "\n# setup target output directories";
+    ofs << "\n\n# setup target output directories";
     ofs << "\nset(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/lib)";
     ofs << "\nset(CMAKE_LIBRARY_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/lib)";
     ofs << "\nset(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin)";
@@ -246,7 +247,46 @@ int main(int argc, char** argv)
         ofs << "\n\tPUBLIC src";
         ofs << "\n)";
 
-        // Link to any libs that exist
+        if (argParser.ContainsOption("-gs"))
+        {
+            ofs << "\n\n# DOWNLOAD ALL SUBMODULES";
+            ofs << "\nfind_package(Git QUIET)";
+            ofs << "\nif(GIT_FOUND AND EXISTS \"${PROJECT_SOURCE_DIR}/.git\")";
+            ofs << "\n# Update submodules as needed";
+            ofs << "\n    option(GIT_SUBMODULE \"Check submodules during build\" ON)";
+            ofs << "\n    if(GIT_SUBMODULE)";
+            ofs << "\n        message(STATUS \"Submodule update\")";
+            ofs << "\n        execute_process(COMMAND ${GIT_EXECUTABLE} submodule update --init --recursive";
+            ofs << "\n                        WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}";
+            ofs << "\n                        RESULT_VARIABLE GIT_SUBMOD_RESULT)";
+            ofs << "\n        if(NOT GIT_SUBMOD_RESULT EQUAL \"0\")";
+            ofs << "\n            message(FATAL_ERROR \"git submodule update --init failed with ${GIT_SUBMOD_RESULT}, please checkout submodules\")";
+            ofs << "\n        endif()";
+            ofs << "\n    endif()";
+            ofs << "\nendif()";
+            ofs << "\n";
+            ofs << "\n# CHECK THAT ALL SUBMODULES EXIST";
+            ofs << "\n#if(NOT EXISTS \"${PROJECT_SOURCE_DIR}/external/<PROJECT ROOT DIRECTORY>/CMakeLists.txt\")";
+            ofs << "\n#   message(FATAL_ERROR \"<PROJECT NAME> submodule was not downloaded! GIT_SUBMODULE was turned off or failed. Please update submodules and try again.\")";
+            ofs << "\n#endif()";
+        }
+
+        // include the libraries and submodules
+        ofs << "\n\n# add subdirectories here";
+        for (int i = 0; i < libraries.size(); i++)
+        {
+            ofs << "\nadd_subdirectory(src/" << libraries[i].c_str() << ")";
+        }
+
+        for (int i = 0; i < submods.size(); i++)
+        {
+            ofs << "\nadd_subdirectory(src/" << submods[i].c_str() << ")";
+        }
+
+        // Link to any libs that exist or add space to link to submodules added through git
+        if (libraries.size() > 0 || argParser.ContainsOption("-gs"))
+        {
+            
             ofs << "\n\ntarget_link_directories(${PROJECT_NAME} ";
             for (int i = 0; i < libraries.size(); i++)
             {
@@ -262,16 +302,6 @@ int main(int argc, char** argv)
             ofs << ")";
         }
         
-
-    // include the libraries and submodules
-    for (int i = 0; i < libraries.size(); i++)
-    {
-        ofs << "\nadd_subdirectory(src/" << libraries[i].c_str() << ")";
-    }
-
-    for (int i = 0; i < submods.size(); i++)
-    {
-        ofs << "\nadd_subdirectory(src/" << submods[i].c_str() << ")";
     }
 
     ofs.close();