[ovs-dev] [PATCH] INSTALL.md: Document how to add custom compiler flags.

[Russell Bryant]

On 04/02/2015 12:52 PM, Ben Pfaff wrote:
> CC: Mark B Kavanagh <mark.b.kavanagh at intel.com>
> Signed-off-by: Ben Pfaff <blp at nicira.com>
> ---
>  INSTALL.md | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/INSTALL.md b/INSTALL.md
> index 273093b..cde9a20 100644
> --- a/INSTALL.md
> +++ b/INSTALL.md
> @@ -192,6 +192,14 @@ To use 'clang' compiler:
>  
>        `% ./configure CC=clang`
>  
> +To supply special flags to the C compiler, specify them as CFLAGS on
> +the configure command line.  If you want the default CFLAGS, which
> +include "-g" to build debug symbols and "-O2" to enable optimizations,
> +you must include them yourself.  For example, to build with the
> +default CFLAGS plus "-mssse3", you might run configure as follows:
> +
> +      `% ./configure CFLAGS="-g -O2 -mssse3"`
> +
>  To build the Linux kernel module, so that you can run the
>  kernel-based switch, pass the location of the kernel build
>  directory on --with-linux.  For example, to build for a running
> 

Acked-by: Russell Bryant <rbryant at redhat.com>

On a related note, it's probably worth adding a similar note about
custom CFLAGS for the Linux kernel module.  For example, I have to use
this flag:

    $ make EXTRA_CFLAGS="-Wno-error=date-time"

I can post a follow-up patch for that though if you'd like.

-- 
Russell Bryant