[PATCH 00/15] Add support for clang LTO
From: mark.rutland@arm.com (Mark Rutland)
Date: 2017-11-03 18:49:18
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On Fri, Nov 03, 2017 at 11:36:33AM -0700, Nick Desaulniers wrote:
On Fri, Nov 3, 2017 at 11:29 AM, Mark Rutland [off-list ref] wrote:quoted
On Fri, Nov 03, 2017 at 11:07:04AM -0700, Nick Desaulniers wrote:quoted
On Fri, Nov 3, 2017 at 10:51 AM, Mark Rutland [off-list ref] wrote:quoted
I had to create an aarch64-linux-gnu-clang wrapper, too. I'm not sure if there's build system help to avoid needing that?Gah! So a BIG difference with Clang vs GCC for cross compiling is that Clang by default ships with all backends enabled, and uses a `-target <triple>` CFLAG to determine the arch to cross compile for, while GCC is configured at compile time to support one back end, IIUC.Yup. I initally tried passing CC=clang\ --target=aarch64-linux-gnu ... but since that conflicts with CROSS_COMPILE, you then have to override AS, LD, OBJCOPY, etc, separately too.make CC=clang CROSS_COMPILE=aarch64-linux-gnu- I think you may need a trailing hyphen on your target as it gets prefixed onto as and ld: Makefile: 348 # Make variables (CC, etc...) 349 AS = $(CROSS_COMPILE)as 350 LD = $(CROSS_COMPILE)ld
I thought CC=clang CROSS_COMPILE=foo- would result in foo-clang, but evidently this is not the case. I must've meseed up something else; sorry for the noise. Thanks for correcting me; now I can go delete my wrapper. :) Thanks, Mark.