[CMake] Removing compiler options

[Robert Dailey]

I still really need help with this. It's a blocker at this point for
me. Help is greatly appreciated; thanks in advance.

On Sun, Nov 9, 2014 at 10:02 PM, Robert Dailey <rcdailey.lists at gmail.com> wrote:
> When setting up a CLR project through CMake, it becomes important to
> be able to *remove* compiler options at the project level. For
> example, the following need to be removed (MSVC12):
>
> /RTC1
> /EHsc
>
> There is no "remove_compile_options()" (which would be convenient).
> Any reason why this doesn't exist?
>
> Right now I'm trying to remove these via CMAKE_CXX_FLAGS locally but
> this doesn't work unless I forcefully change the cache. But this is a
> permanent operation that affects *all* projects, which I do not want.
> This is crazy, I'm hoping there is a better way. I'm using CMake 3.1
> RC1. Can anyone help me figure out how to remove compiler options on a
> per-project basis?
>
> Here is what I'm doing:
>
> function( add_clr_library target_name references )
>     set( source_files ${ARGN} )
>
>     set( default_references
>         System
>         System.Core
>         System.Data
>         System.Drawing
>         #System.Xml
>         #WindowsBase
>     )
>
>     if( CMAKE_CXX_FLAGS_DEBUG MATCHES "/RTC1" )
>         string( REGEX REPLACE "/RTC(su|[1su])" ""
> CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG}" )
>     endif()
>
>     if( CMAKE_CXX_FLAGS MATCHES "/EHsc" )
>         string( REPLACE "/EHsc" "" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}" )
>     endif()
>
>     add_library( ${target_name} SHARED ${source_files} )
>
>     list( APPEND references ${default_references} )
>
>     set_target_properties( ${target_name} PROPERTIES
>         VS_DOTNET_REFERENCES "${references}"
>         VS_DOTNET_TARGET_FRAMEWORK_VERSION "v4.5"
>         COMPILE_FLAGS "/clr /EHa"
>         DEBUG_POSTFIX "d"
>     )
> endfunction()