[CMake] 64bit linking on linux

[Aaron Turner]

On Wed, Feb 18, 2009 at 6:52 AM, Bill Hoffman <bill.hoffman at kitware.com> wrote:
> Birju Prajapati wrote:
>>
>> I've figured it out. I added the following lines into the root
>> CMakeLists.txt file:
>>
>>
>> SET(CMAKE_CXX_FLAGS "-m64")
>>
>> SET(CMAKE_C_FLAGS "-m64")
>>
>> SET(CMAKE_EXE_LINKER_FLAGS "-m64")
>>
>> SET(CMAKE_MODULE_LINKER_FLAGS "-m64")
>>
>> SET(CMAKE_SHARED_LINKER_FLAGS "-m64")
>>
>>
>
> That is not the preferable way to do this.  As it hard codes flags into the
> CMake file.  The way I would do it is:
>
> export CXXFLAGS=-m64
> export CFLAGS=-m64
> export LDFLAGS=-m64
>
> cmake ../myproject
>
> If those environment variables are set BEFORE you run cmake, then cmake will
> put them into the cache correctly.

Couldn't you use the check_c_source_runs() macro to test if your
system supports the -m64 flag?  That way you wouldn't need to require
the user to specify it (always fraught with peril).


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Aaron Turner
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