Re: [PATCH v2 3/3] objtool: use global host flags for compilation

From: Josh Poimboeuf
Date: Tue Feb 27 2018 - 12:49:40 EST


On Mon, Feb 26, 2018 at 07:41:48PM +0100, Robin Jarry wrote:
> When libelf headers and libs are not found and CONFIG_UNWINDER_ORC is
> selected, there is a make error introduced by
> commit 3dd40cb320fe ("objtool: Upgrade libelf-devel warning to error for
> CONFIG_ORC_UNWINDER").
>
> Host headers and libs may be in a non-standard location and the check is
> performed without host flags. Make sure to use host flags for the check
> and for building objtool. Remove duplicate flags.
>
> Fixes: 3b27a0c85d70 ("objtool: Detect and warn if libelf is missing and don't break the build")
> Signed-off-by: Robin Jarry <robin.jarry@xxxxxxxxx>
> Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> ---
> Makefile | 2 +-
> tools/objtool/Makefile | 4 ++--
> 2 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/Makefile b/Makefile
> index f7c543cebfc6..c9dc35fe0e48 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -955,7 +955,7 @@ export mod_sign_cmd
>
> ifdef CONFIG_STACK_VALIDATION
> has_libelf := $(call try-run,\
> - echo "int main() {}" | $(HOSTCC) -xc -o /dev/null -lelf -,1,0)
> + echo "int main() {}" | $(HOSTCC) $(HOSTLDFLAGS) -xc -o /dev/null -lelf -,1,0)

This should probably also have HOSTCFLAGS, since the objtool makefile
uses it as well.

--
Josh