How do YOU reduce compile time, and linking time f

Question

How do YOU reduce compile time, and linking time for VC++ projects (native C++)?

Please specify if each suggestion applies to debug, release, or both.

Answer 1

If you have large complex headers that must be included by most of the .cpp files in your build process, and which are not changed very often, you can precompile them. In a Visual C++ project with a typical configuration, this is simply a matter of including them in stdafx.h. This feature has its detractors, but libraries that make full use of templates tend to have a lot of stuff in headers, and precompiled headers are the simplest way to speed up builds in that case.

Answer 2

We use Xoreax's Incredibuild to run compilation in parallel across multiple machines.

Answer 3

Our development machines are all quad-core and we use Visual Studio 2008 supports parallel compiling. I am uncertain as to whether all editions of VS can do this.

We have a solution file with approximately 168 individual projects, and compile this way takes about 25 minutes on our quad-core machines, compared to about 90 minutes on the single core laptops we give to summer students. Not exactly comparable machines but you get the idea :)

Answer 4

The compile speed question is interesting enough that Stroustrup has it in his FAQ.

Answer 5

With Visual C++, there is a method, some refer to as Unity, that improves link time significantly by reducing the number of object modules.

This involves concatenating the C++ code, usually in groups by library. This of course makes editing the code much more difficult, and you will run into namespace collisions unless you use them well. It keeps you from using "using namespace foo";

Several teams at our company have elaborate systems to take the normal C++ files and concatenate them at compile time as a build step. The reduction in link times can be enormous.

Answer 6

Compile Time:
If you have IncrediBuild, compile time won't be a problem. If you don't have a IncrediBuild, try the "unity build" method. It combine multiple cpp files to a single cpp file so the whole compile time is reduced.
Link Time:
The "unity build" method also contribute to reduce the link time but not much. How ever, you can check if the "Whole global optimization" and "LTCG" are enabled, while these flags make the program fast, they DO make the link SLOW.
Try turning off the "Whole Global Optimization" and set LTCG to "Default" the link time might be reduced by 5/6.
(LTCG stands for Link Time Code Generation)