[cfe-dev] too slow to build clang

[Douglas Gregor]

On Jan 19, 2009, at 10:09 AM, Rick Mann wrote:

>
> On Jan 19, 2009, at 07:44:36, Douglas Gregor wrote:
>
>> On Jan 19, 2009, at 5:52 AM, Jiandong Lu wrote:
>>
>>> add only debug statement to output something ,and than build clang
>>> in my FreeBSD 7.1 in vmware.
>>> I found it took about tens of minutes.Although my machine is a
>>> little slow (celeron 2.4 G cpu),
>>> I think it took too many minutes.Maybe there something is wrong.
>>>
>>
>> Clang and LLVM are relatively large, so it does take some time to
>> compile them. The biggest issue is often memory: does your VMware
>> virtual machine have at least 1 GB memory?
>>
>> Also, it helps to configure LLVM with --enable-targets=<some small
>> subset of targets>. Otherwise, you're spending a lot of time
>> compiling and linking back-end targets you probably don't care about
>> (Sparc, Cell, etc.).
>
> It seemed to me like he was saying that after the initial build,
> changing a single file (presumably not a header file) still required a
> substantial rebuild. But I'm just speculating. Using the Xcode build
> project, I have not experienced this to be the case.


The rebuild is pretty minimal for the makefiles, too, although linking  
takes a while.

	- Doug