Re: [Boost-build] Choosing clang toolset on Windows

From: Steven Watanabe (watanabesj_at_[hidden])
Date: 2019-07-23 23:16:05

AMDG

On 7/23/19 6:23 AM, Edward Diener via Boost-build wrote:
> On 7/23/2019 6:17 AM, Steven Watanabe via Boost-build wrote:
>> On 7/22/19 8:17 PM, Edward Diener via Boost-build wrote:
>>> If I have on Windows in my user-config.jam
>>>
>>> import toolset ;
>>> using clang-win : 8.0 : E:/programming/bat/cp_clangwin80.bat : etc. ;
>>> using clang : 8.0 : E:/programming/bat/cp_clang80.bat : etc. ;
>>>
>>
>> Flip the order.  `using clang` is the same as `using clang-linux`
>> The first one listed is the default.
>>
> 
> Ok, thanks ! But why does a 'default' matter when the two toolsets above
> are different ?
> 
> Does not that mean that if I flip them that 'b2 toolset=clang-win-8.0'
> chooses the 'clang' toolset over the 'clang-win' toolset

It's impossible to have a `clang` toolset.  It's always
clang-win, clang-linux, clang-darwin, etc.  When you say
`using clang` it will always pick one of these based on
your platform.

When you specify toolset=clang, Boost.Build will fill in
the version and platform with the first ones specified.
If you specify the version or platform explicitly, then
you get whatever you asked for.

In short, your setup above has:
toolset=clang -> clang-win-8.0
toolset=clang-win -> clang-win-8.0
toolset=clang-linux -> clang-linux-8.0

What you are asking for is:
toolset=clang -> clang-linux-8.0
which can be achieved by putting `using clang` before
`using clang-win.`

> if the first
> one listed is the default from what you are saying ? This is not what I
> want.
> 
> Like I said if I change the 'clang' toolset definition to 'clang-linux',
> then invoking 'b2 toolset=clang-linux'

You don't need to change the definition to clang-linux.  You can
use toolset=clang-linux with your current setup.

> or 'b2 toolset=clang-win' chooses
> the correct toolset, but I do not understand why it should not work as
> above. I guess I hate to have to type the extra letters of 'clang-linux'
> as opposed to just 'clang' when it seems it should work as is.
> 

In Christ,
Steven Watanabe