Building OCCT is super slow!

[petrasvestartas]

For C++ use only without any vizualization, do I need build all the occt or the smaller portion of it?
It takes 1 hour to build on my pc...

[dpasukhi]

Hello, you have flexibility to turn on/turn off modules.
Also, 7.9.0+ provide precompiled headers (use -D BUILD_USE_PCH=ON) (Up to 5x times faster build using CLang)

Also, improving performance: (-D BUILD_OPT_PROFILE=Production)

There are 5 modules.

-D BUILD_MODULE_ApplicationFramework = OFF
-D BUILD_MODULE_DataExchange = OFF
-D BUILD_MODULE_Draw = OFF
-D BUILD_MODULE_FoundationClasses =OFF
-D BUILD_MODULE_ModelingAlgorithms = OFF
-D BUILD_MODULE_ModelingData = OFF
-D BUILD_MODULE_Visualization= ON

[dpasukhi]

Depends what you build (which models are enabled).
Compilation share the % of building. If not - use Ninja :)

[dpasukhi]

But I even don't have issue to build on Aaarch64 (chromeOS), personal tablet.
So, I assume not a high problem to build. 2-4 cores is enough, but for sure not fast.

[dpasukhi]

Also, I would recommend CLang, which is much faster and takes less memory.

[petrasvestartas]

I just tried to measure the time. I want to use OCC both in C++ and Python.
For one operating system it takes 20 minutes to build for the core algorithms (without any algorithms for visualization).
I tried to make a python binding build system for python 3.9, 3.10, 3.11, 3.12 it took more than 1 hour.
https://github.com/petrasvestartas/compas_occt/actions/runs/15096779603

Do you see in my cmakelists what could be optimized even more:
https://github.com/petrasvestartas/compas_occt/blob/main/CMakeLists.txt

For me it is the first time, I am building such a serious library. Any advice would be much appreciated.

[dpasukhi]

DBUILD_USE_PCH=ON
Enables the compilation speed up. Nothing more can improve.
Build type (production) is increasing compilation time by 2 times. You can move to "Default" from "Production"