From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751445AbaIFAWA (ORCPT ); Fri, 5 Sep 2014 20:22:00 -0400 Received: from mail-pd0-f176.google.com ([209.85.192.176]:43305 "EHLO mail-pd0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750817AbaIFAV5 (ORCPT ); Fri, 5 Sep 2014 20:21:57 -0400 From: behanw@converseincode.com To: mmarek@suse.cz Cc: linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, Behan Webster Subject: [PATCH] kbuild, LLVMLinux: Add better clang cross build support Date: Fri, 5 Sep 2014 17:21:49 -0700 Message-Id: <1409962909-14660-1-git-send-email-behanw@converseincode.com> X-Mailer: git-send-email 1.9.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Behan Webster Add cross target to CC if using clang. Also add custom gcc toolchain path for fallback gcc tools. COMPILER is previously set to "clang" if CC=clang was set from the make command line. So -target and -gcc-toolchain can be added to CC, since we already know that it is set. Clang will fallback to using things like ld, as, and libgcc if (respectively) one of the llvm linkers isn't available, the integrated assembler is turned off, or an appropriately cross-compiled version of compiler-rt isn't available. To this end, you can specify the path to this fallback gcc toolchain with GCC_TOOLCHAIN. Signed-off-by: Behan Webster --- Makefile | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/Makefile b/Makefile index 2893d7f..c772619 100644 --- a/Makefile +++ b/Makefile @@ -360,7 +360,16 @@ include $(srctree)/scripts/Kbuild.include # Make variables (CC, etc...) AS = $(CROSS_COMPILE)as LD = $(CROSS_COMPILE)ld +ifeq ($(COMPILER),clang) +ifneq ($(CROSS_COMPILE),) +CC += -target $(CROSS_COMPILE:%-=%) +endif +ifneq ($(GCC_TOOLCHAIN),) +CC += -gcc-toolchain $(GCC_TOOLCHAIN) +endif +else CC = $(CROSS_COMPILE)gcc +endif CPP = $(CC) -E AR = $(CROSS_COMPILE)ar NM = $(CROSS_COMPILE)nm -- 1.9.1