[Scons-users] Per target env variables

[Mats Wichmann]

On 09/10/2018 08:40 AM, Hua Yanghao wrote:
> Not sure how Object(CFLAGS = old + new) is handled, but I have
> verified that definitely going to customize for each and every object,
> and no clash seen.
> If this, behind the scene is also using a Clone() somehow I starts to
> understand why my build startup is a bit slow (totally acceptable
> though, e.g. for a build that creates 22 different target, a few
> hundred C files each), around 9 seconds before the first build prints
> on screen.

I've looked at the work done to clone, and it's a fair bit. I've got a
project that does a lot of clones, and is slow to start up, but I'm far
from convinced it's the cost of cloning that makes it so.  I'd suggest
if startup time isn't bugging you, don't worry about it.  If startup
time *is* bugging you, then clones are _one_ place to look.


>> On Wed, Sep 05, 2018 at 11:57:38PM -0400, Bill Deegan wrote:
>>> Here's the caveat.
>>> Don't make a gazillion Clone's they're not lightweight.
>>> If you make 100, it won't kill you, if you make 1000's you may start seeing
>>> memory and speed impacted.
>>
...
>>
>> But in this scheme we clone a lot.  Maybe this is too heavyweight?
>>
>> Regards,
>> Petteri