[PATCH v2 5/5] Makefile.debug: set -g unconditional on CONFIG_DEBUG_INFO_SPLIT

From: Nick Desaulniers
Date: Wed Aug 31 2022 - 14:44:46 EST


Dmitrii, Fangrui, and Mashahiro note:

Before GCC 11 and Clang 12 -gsplit-dwarf implicitly uses -g2.

Fix CONFIG_DEBUG_INFO_SPLIT for gcc-11+ & clang-12+ which now need -g
specified in order for -gsplit-dwarf to work at all.

-gsplit-dwarf has been mutually exclusive with -g since support for
CONFIG_DEBUG_INFO_SPLIT was introduced in
commit 866ced950bcd ("kbuild: Support split debug info v4")
I don't think it ever needed to be.

Link: https://lore.kernel.org/lkml/20220815013317.26121-1-dmitrii.bundin.a@xxxxxxxxx/
Link: https://lore.kernel.org/lkml/CAK7LNARPAmsJD5XKAw7m_X2g7Fi-CAAsWDQiP7+ANBjkg7R7ng@xxxxxxxxxxxxxx/
Link: https://reviews.llvm.org/D80391
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Reported-by: Dmitrii Bundin <dmitrii.bundin.a@xxxxxxxxx>
Reported-by: Fangrui Song <maskray@xxxxxxxxxx>
Reported-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
Suggested-by: Dmitrii Bundin <dmitrii.bundin.a@xxxxxxxxx>
Signed-off-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
---
Changes v1 -> v2:
* Add reference to 866ced950bcd, cc Andi, in commit message.

scripts/Makefile.debug | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/scripts/Makefile.debug b/scripts/Makefile.debug
index 46e88f0ca998..b6eb532af3cc 100644
--- a/scripts/Makefile.debug
+++ b/scripts/Makefile.debug
@@ -1,10 +1,8 @@
-DEBUG_CFLAGS :=
+DEBUG_CFLAGS := -g
+KBUILD_AFLAGS += -g

ifdef CONFIG_DEBUG_INFO_SPLIT
DEBUG_CFLAGS += -gsplit-dwarf
-else
-DEBUG_CFLAGS += -g
-KBUILD_AFLAGS += -g
endif

ifdef CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT
--
2.37.2.672.g94769d06f0-goog