Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753457AbbGNJFe (ORCPT ); Tue, 14 Jul 2015 05:05:34 -0400 Received: from smtprelay.synopsys.com ([198.182.60.111]:50599 "EHLO smtprelay.synopsys.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1751277AbbGNJFa (ORCPT ); Tue, 14 Jul 2015 05:05:30 -0400 From: Alexey Brodkin To: linux-arch@vger.kernel.org Cc: Alexey Brodkin , Vineet Gupta , Aaro Koskinen , Jiri Olsa , Paul Mackerras , Peter Zijlstra , Arnaldo Carvalho de Melo , linux-kernel@vger.kernel.org Subject: [PATCH] perf tools: Really allow to specify custom CC, AR or LD Date: Tue, 14 Jul 2015 12:05:20 +0300 Message-Id: <1436864720-26316-1-git-send-email-abrodkin@synopsys.com> X-Mailer: git-send-email 2.4.3 In-Reply-To: <20150714063152.GD22977@krava.local> References: <20150714063152.GD22977@krava.local> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2713 Lines: 74 Commit 5ef7bbb09f7b ("perf tools: Allow to specify custom linker command") was meant to enable usage non $(CROSS_COMPILE)ld linker during perf building. But implementation didn't take in account fact that LD is a pre-defined variable in GNU Make. I.e. it is always defined. Which means there's no point to check "LD ?= ..." because it will never succeed. And so LD will be either that explicitly passed to make like this: ------->8------- make LD=path_to_my_ld ... ------->8------- or default value, which is host's "ld". Latter leads to failure of cross-linkage because instead of cross linker "$(CROSS_COMPILE)ld" host's "ld" is used. Fortunately there's a way to do correct substitution of $(CROSS_COMPILE)ld with user defined LD on command-line. As a reference was used implementation in "tools/lib/traceevent/Makefile". Build tested for x86_64 and ARC. Thanks Jiri for this hint. Signed-off-by: Alexey Brodkin Cc: Vineet Gupta Cc: Aaro Koskinen Cc: Jiri Olsa Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Arnaldo Carvalho de Melo Cc: linux-kernel@vger.kernel.org --- tools/perf/Makefile.perf | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-) diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf index 7a4b549..bba3463 100644 --- a/tools/perf/Makefile.perf +++ b/tools/perf/Makefile.perf @@ -109,9 +109,22 @@ $(OUTPUT)PERF-VERSION-FILE: ../../.git/HEAD $(Q)$(SHELL_PATH) util/PERF-VERSION-GEN $(OUTPUT) $(Q)touch $(OUTPUT)PERF-VERSION-FILE -CC = $(CROSS_COMPILE)gcc -LD ?= $(CROSS_COMPILE)ld -AR = $(CROSS_COMPILE)ar +# Makefiles suck: This macro sets a default value of $(2) for the +# variable named by $(1), unless the variable has been set by +# environment or command line. This is necessary for CC and AR +# because make sets default values, so the simpler ?= approach +# won't work as expected. +define allow-override + $(if $(or $(findstring environment,$(origin $(1))),\ + $(findstring command line,$(origin $(1)))),,\ + $(eval $(1) = $(2))) +endef + +# Allow setting CC and AR and LD, or setting CROSS_COMPILE as a prefix. +$(call allow-override,CC,$(CROSS_COMPILE)gcc) +$(call allow-override,AR,$(CROSS_COMPILE)ar) +$(call allow-override,LD,$(CROSS_COMPILE)ld) + PKG_CONFIG = $(CROSS_COMPILE)pkg-config RM = rm -f -- 2.4.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/