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From:   Adrian Ratiu <adrian.ratiu@collabora.com>
To:     llvm@lists.linux.dev
Cc:     linux-kernel@vger.kernel.org,
        Nick Desaulniers <ndesaulniers@google.com>,
        Nathan Chancellor <nathan@kernel.org>,
        Manoj Gupta <manojgupta@chromium.com>
Subject: [PATCH] tools: fix unavoidable GCC call in Clang builds
Date:   Thu, 17 Feb 2022 05:36:48 +0200
Message-Id: <20220217033648.1453303-1-adrian.ratiu@collabora.com>
MIME-Version: 1.0
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In ChromeOS and Gentoo we catch any unwanted mixed Clang/LLVM
and GCC/binutils usage via toolchain wrappers which fail builds.
This has revealed that GCC is called unconditionally in Clang
configured builds to populate GCC_TOOLCHAIN_DIR.

Allow overriding the variable to avoid the GCC call - in our
case we can set GCC_TOOLCHAIN_DIR directly in the ebuild recipe.

Suggested-by: Manoj Gupta <manojgupta@chromium.com>
Signed-off-by: Adrian Ratiu <adrian.ratiu@collabora.com>
---
 tools/scripts/Makefile.include | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/scripts/Makefile.include b/tools/scripts/Makefile.include
index 79d102304470..98c098c064dd 100644
--- a/tools/scripts/Makefile.include
+++ b/tools/scripts/Makefile.include
@@ -90,7 +90,7 @@ EXTRA_WARNINGS += -Wstrict-aliasing=3
 
 else ifneq ($(CROSS_COMPILE),)
 CLANG_CROSS_FLAGS := --target=$(notdir $(CROSS_COMPILE:%-=%))
-GCC_TOOLCHAIN_DIR := $(dir $(shell which $(CROSS_COMPILE)gcc 2>/dev/null))
+GCC_TOOLCHAIN_DIR ?= $(dir $(shell which $(CROSS_COMPILE)gcc 2>/dev/null))
 ifneq ($(GCC_TOOLCHAIN_DIR),)
 CLANG_CROSS_FLAGS += --prefix=$(GCC_TOOLCHAIN_DIR)$(notdir $(CROSS_COMPILE))
 CLANG_CROSS_FLAGS += --sysroot=$(shell $(CROSS_COMPILE)gcc -print-sysroot)
-- 
2.35.0