[CMake] Antwort: Re: Re: Antwort: Antwort: Re:Antwort: Re: Toolchain with non-gcc argument format

[oliver.zabel at egoproducts.com]

Hi Eric, 

thanks a lot for your help! i'm going to try it on the dev mailing list.

Cheers, 
Oliver



Von:    Eric Noulard <eric.noulard at gmail.com>
An:     oliver.zabel at egoproducts.com
Kopie:  CMake Mailinglist <cmake at cmake.org>
Datum:  22.11.2017 09:49
Betreff:        Re: Re: [CMake] Antwort: Antwort: Re:Antwort: Re: 
Toolchain with non-gcc argument format



Hi Olivier,

Putting the list back.
You may try developer list as well.


2017-11-22 9:02 GMT+01:00 <oliver.zabel at egoproducts.com>:
Hi, 

Is there really no way to override this var with a toolchain file? that 
seems somehow strange to me, since CMAKE is so configurable that i can't 
change "-I" to "-include=" .... what do i have to do?


I'm sorry I'm a little short in time to investigate that with you at the 
moment and I hope some other people may step in.
The var "CMAKE_INCLUDE_FLAG_C" is NOT a toolchain file variable and it 
won't end-up in the cache file.
AFAIK It is **only** used in compiler detection, e.g. at early stage of 
project configuration when processing project(...)
or enable_language(..)

Adding new toolchain is not as flexible as adding a new **kind** of 
compiler.
The knobs accessing for writing a toolchain are described here:
https://cmake.org/cmake/help/v3.10/manual/cmake-toolchains.7.html

There you can see that:
"Languages are enabled by the project() command. Language-specific 
built-in variables, such as CMAKE_CXX_COMPILER, CMAKE_CXX_COMPILER_ID etc 
are set by invoking the project() command."

Unless I'm wrong the toolchain mechanism does not include the capability 
to change "-I" to "-include".

Now adding a new "kind" of compiler, a.k.a. compiler ID, enables you to 
specify that include directive flag is " -include" (and many other things 
as well)
Adding a new compiler ID requires to add files in 
<CMakePrefix>/Modules/Compiler (see 
https://github.com/Kitware/CMake/tree/master/Modules/Compiler)

as you can see it requires at least a couple of file to find a compiler 
and one file per supported language (C, CXX, etc...)
in the C or CXX specific file you may use CMAKE_INCLUDE_FLAG_C and other 
variables:

see e.g.:
https://github.com/Kitware/CMake/blob/master/Modules/Compiler/TI-C.cmake 

I did never add a new kind of compiler so I hope people with more 
knowlegde than me in this area will explain that part better than me.

Eric

 



2017-11-16 9:44 GMT+01:00 <oliver.zabel at egoproducts.com>: 
I did not find the CMAKE_INCLUDE_FLAG_C in the CMake cache - is it 
possible that this is somehow ignored? 

This variable is used by CMake **builtin compiler** discovery and 
configuration. 
The file are are put in "Modules/Compiler" there is one per-langage and 
per-compiler ID: 
https://cmake.org/cmake/help/v3.7/variable/CMAKE_LANG_COMPILER_ID.html 

I don't know the exact processing order of this set of files. 

Toolchain files: 
https://cmake.org/cmake/help/v3.7/manual/cmake-toolchains.7.html 
does not use or contain such variables. 

-- 
Eric 




-- 
Eric

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://public.kitware.com/pipermail/cmake/attachments/20171122/f8d5e557/attachment.html>