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From:   Masahiro Yamada <masahiroy@kernel.org>
To:     linux-kbuild@vger.kernel.org
Cc:     clang-built-linux@googlegroups.com,
        Nick Desaulniers <ndesaulniers@google.com>,
        Masahiro Yamada <masahiroy@kernel.org>,
        Nathan Chancellor <nathan@kernel.org>,
        linux-kernel@vger.kernel.org
Subject: [PATCH 4/4] kbuild: dwarf: use AS_VERSION instead of test_dwarf5_support.sh
Date:   Thu,  4 Mar 2021 03:33:33 +0900
Message-Id: <20210303183333.46543-4-masahiroy@kernel.org>
In-Reply-To: <20210303183333.46543-1-masahiroy@kernel.org>
References: <20210303183333.46543-1-masahiroy@kernel.org>
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The test code in scripts/test_dwarf5_support.sh is somewhat difficult
to understand, but after all, we want to check binutils >= 2.35.2

From the former discussion, the requrement for generating DRAWF v5 from
C code is as follows:

 - gcc + binutils as     -> requires gcc 5.0+ (but 7.0+ for full support)
 - clang + binutils as   -> requires binutils 2.35.2+
 - clang + integrated as -> OK

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---

 lib/Kconfig.debug              | 3 +--
 scripts/test_dwarf5_support.sh | 8 --------
 2 files changed, 1 insertion(+), 10 deletions(-)
 delete mode 100755 scripts/test_dwarf5_support.sh

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 2779c29d9981..f3337a38925d 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -284,8 +284,7 @@ config DEBUG_INFO_DWARF4
 
 config DEBUG_INFO_DWARF5
 	bool "Generate DWARF Version 5 debuginfo"
-	depends on GCC_VERSION >= 50000 || CC_IS_CLANG
-	depends on CC_IS_GCC || $(success,$(srctree)/scripts/test_dwarf5_support.sh $(CC) $(CLANG_FLAGS))
+	depends on GCC_VERSION >= 50000 || (CC_IS_CLANG && AS_IS_GNU && AS_VERSION >= 23502) || (CC_IS_CLANG && AS_IS_LLVM)
 	depends on !DEBUG_INFO_BTF
 	help
 	  Generate DWARF v5 debug info. Requires binutils 2.35.2, gcc 5.0+ (gcc
diff --git a/scripts/test_dwarf5_support.sh b/scripts/test_dwarf5_support.sh
deleted file mode 100755
index c46e2456b47a..000000000000
--- a/scripts/test_dwarf5_support.sh
+++ /dev/null
@@ -1,8 +0,0 @@
-#!/bin/sh
-# SPDX-License-Identifier: GPL-2.0
-
-# Test that the assembler doesn't need -Wa,-gdwarf-5 when presented with DWARF
-# v5 input, such as `.file 0` and `md5 0x00`. Should be fixed in GNU binutils
-# 2.35.2. https://sourceware.org/bugzilla/show_bug.cgi?id=25611
-echo '.file 0 "filename" md5 0x7a0b65214090b6693bd1dc24dd248245' | \
-  $* -gdwarf-5 -Wno-unused-command-line-argument -c -x assembler -o /dev/null -
-- 
2.27.0