[PATCH v2 3/3] kbuild: dwarf: use AS_VERSION instead of test_dwarf5_support.sh

Masahiro Yamada
2021-03-15T16:16:02Z

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 requirement for generating DWARF v5 from
C code is as follows:

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

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
---

Changes in v2:
- fix typos
- simplify the dependency expression

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 b479ae609a31..c85d5f7a1aeb 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_LLVM || (AS_IS_GNU && AS_VERSION >= 23502)))
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