From 23b01929f7255bd226f1a3bae29bff6061ffe8c2 Mon Sep 17 00:00:00 2001
From: tamasmeszaros <meszaros.q@gmail.com>
Date: Thu, 10 Aug 2023 17:10:17 +0200
Subject: [PATCH] Deal with multithreaded builds of individual projects

---
 cmake/modules/AddCMakeProject.cmake | 19 +++++++++++++++++--
 deps/+OCCT/OCCT.cmake               |  2 ++
 2 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/cmake/modules/AddCMakeProject.cmake b/cmake/modules/AddCMakeProject.cmake
index c8bef0df1e..eeb5c8a9e0 100644
--- a/cmake/modules/AddCMakeProject.cmake
+++ b/cmake/modules/AddCMakeProject.cmake
@@ -1,4 +1,5 @@
 include(ExternalProject)
+include(ProcessorCount)
 
 set(DESTDIR "${CMAKE_CURRENT_BINARY_DIR}/destdir" CACHE PATH "Destination directory")
 set(DEP_DOWNLOAD_DIR ${CMAKE_CURRENT_BINARY_DIR} CACHE PATH "Path for downloaded source packages.")
@@ -13,7 +14,21 @@ endif ()
 # The value of CMAKE_BUILD_TYPE will be used for building each dependency even if the 
 # generator is multi-config. Use this var to specify build type regardless of the generator. 
 function(add_cmake_project projectname)
-    cmake_parse_arguments(P_ARGS "" "INSTALL_DIR;BUILD_COMMAND;INSTALL_COMMAND" "CMAKE_ARGS" ${ARGN})
+    cmake_parse_arguments(P_ARGS "" "INSTALL_DIR;BUILD_COMMAND;INSTALL_COMMAND;MAX_THREADS" "CMAKE_ARGS" ${ARGN})
+
+    set(_pcount ${P_ARGS_MAX_THREADS})
+    if (NOT _pcount)
+        ProcessorCount(_pcount)
+    endif ()
+
+    if (_pcount EQUAL 0)
+        set(_pcount 1)
+    endif ()
+
+    set(_build_j "-j${_pcount}")
+    if (CMAKE_GENERATOR MATCHES "Visual Studio")
+        set(_build_j "/m:${_pcount}")
+    endif ()
 
     set(_configs_line -DCMAKE_BUILD_TYPE:STRING=${CMAKE_BUILD_TYPE})
     if (_is_multi)
@@ -38,7 +53,7 @@ function(add_cmake_project projectname)
             ${DEP_CMAKE_OPTS}
             ${P_ARGS_CMAKE_ARGS}
        ${P_ARGS_UNPARSED_ARGUMENTS}
-       BUILD_COMMAND ${CMAKE_COMMAND} --build . --config ${CMAKE_BUILD_TYPE}
+       BUILD_COMMAND ${CMAKE_COMMAND} --build . --config ${CMAKE_BUILD_TYPE} -- ${_build_j}
        INSTALL_COMMAND ${CMAKE_COMMAND} --build . --target install --config ${CMAKE_BUILD_TYPE}
     )
 
diff --git a/deps/+OCCT/OCCT.cmake b/deps/+OCCT/OCCT.cmake
index 5b7743e581..0c004f6b2e 100644
--- a/deps/+OCCT/OCCT.cmake
+++ b/deps/+OCCT/OCCT.cmake
@@ -1,4 +1,6 @@
 add_cmake_project(OCCT
+    MAX_THREADS 4 # Avoid extreme memory usage
+
     #LMBBS: changed version to 7.6.2
     URL https://github.com/Open-Cascade-SAS/OCCT/archive/refs/tags/V7_6_2.zip
     URL_HASH SHA256=c696b923593e8c18d059709717dbf155b3e72fdd283c8522047a790ec3a432c5