[PATCH] D26579: [cmake] Allow CMAKE_BUILD_TYPE=Gentoo

[Michał Górny via llvm-commits]

mgorny added a comment.

In https://reviews.llvm.org/D26579#593702, @mehdi_amini wrote:

> There is a good reason Gento is doing it: to make sure they have full control over compiler flags in the Gentoo configuration.  See here: https://github.com/coreos/portage-stable/blob/master/eclass/cmake-utils.eclass#L43
>
> However accepting the value "Gentoo" here won't address the problem, it'll just mask it. We are expecting values from this list in multiple place.


Yes. I can volunteer to make sure that Gentoo appears there whenever desired, if that's what you need.

> For example in llvm/cmake/modules/HandleLLVMOptions.cmake:
> 
>   # On non-Debug builds cmake automatically defines NDEBUG, so we
>   # explicitly undefine it:
>   if( NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG" )
>    

Just to be clear, here 'Gentoo' is not expected since CMake doesn't control -DNDEBUG for this build type.

>   if (NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG" AND
>       NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "RELWITHDEBINFO")
>     add_flag_if_supported("-gline-tables-only" GLINE_TABLES_ONLY)
>   endif()
>    

…and here it's not expected since appending -g flags implicitly is against a Gentoo policy.

I was also wondering about disabling the -Wl,-O3 and friends but not sure about that yet.


https://reviews.llvm.org/D26579