[Boost-build] darwin: precompiled headers

Subject: [Boost-build] darwin: precompiled headers
From: Jeroen van der Wulp (J.v.d.Wulp_at_[hidden])
Date: 2008-11-08 18:04:01

Hello everyone,

The darwin toolset uses the gcc precompiled header generator, but it 
generates names that end in .pch instead of .gch. As a result the 
precompiled headers are never found and hence never used. This is with 
Boost Build v2 from Boost trunk.

Adding the following line to tools/darwin.jam resolves the issue.

type.set-generated-target-suffix PCH : <toolset>darwin : gch ;

This makes it possible to use precompiled headers on OS X 10.5.5 with 
XCode 3.1. Is it just coincidence or are there any obstacles on other 
versions of OS X (and XCode)? Should it be needed, I also have access to 
a 10.4 machine that I can use for testing.

Best,

Jeroen