慢速连结阶段

Question

Ok guys, I'm having a really unexpected behavior here. Working with a medium size legacy code project I've noticed that compilation was unreasonable slow. Precompiled header is used but it's usefulness is questionable. Anyway, it was fine util I decided to build the project in Release mode. Compilation lasted about 1.5 hours and then linking stage: ~2 hours with total RAM used by the linker ~1.3 GB. Looking at generated *.obj files you can say that something went wrong — their sizes varied from 20 to 50 MB although actual processed files were relatively small. Verbose linker output doesn't say much:

Starting pass 1
Processed /DEFAULTLIB:msvcprt
Processed /DEFAULTLIB:uuid.lib
Processed /DEFAULTLIB:OLDNAMES
*prints nothing for a long time*
Processed /DEFAULTLIB:ws2_32.lib
Processed /DEFAULTLIB:mswsock.lib
*prints nothing for an hour*
...

So I have a couple of questions:

• Can large *.obj files cause such slow linkage?
• Could adding more headers into precompiled make compilation and linking faster?
• What else should I try?

Any help would be greatly appreciated.

Answer 1

Apparently gcc compiler treats "prefix" headers in a different way vc++ treats precompiled header. Just as I thought, adding more headers to precompiled increased it's size to almost 500 MB but generated object files became much smaller and compilation/linking became much faster (although linking duration is about 2-3 minutes now which is not optimal but not as bad as before).