[PATCH] kbuild: Simplify DEBUG_INFO Kconfig handling

From: Sedat Dilek
Date: Sun Aug 16 2020 - 08:33:12 EST


While playing with [1] I saw that the handling
of CONFIG_DEBUG_INFO can be simplified.

[1] https://patchwork.kernel.org/patch/11716107/

Signed-off-by: Sedat Dilek <sedat.dilek@xxxxxxxxx>
---
Makefile | 6 +++++-
lib/Kconfig.debug | 10 ++++------
2 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/Makefile b/Makefile
index 24a4c1b97bb0..f7af83393a49 100644
--- a/Makefile
+++ b/Makefile
@@ -810,13 +810,15 @@ endif
DEBUG_CFLAGS := $(call cc-option, -fno-var-tracking-assignments)

ifdef CONFIG_DEBUG_INFO
+
ifdef CONFIG_DEBUG_INFO_SPLIT
DEBUG_CFLAGS += -gsplit-dwarf
else
DEBUG_CFLAGS += -g
endif
+
KBUILD_AFLAGS += -Wa,-gdwarf-2
-endif
+
ifdef CONFIG_DEBUG_INFO_DWARF4
DEBUG_CFLAGS += -gdwarf-4
endif
@@ -832,6 +834,8 @@ KBUILD_AFLAGS += -gz=zlib
KBUILD_LDFLAGS += --compress-debug-sections=zlib
endif

+endif # CONFIG_DEBUG_INFO
+
KBUILD_CFLAGS += $(DEBUG_CFLAGS)
export DEBUG_CFLAGS

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 9ad9210d70a1..19930c412b93 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -212,9 +212,10 @@ config DEBUG_INFO

If unsure, say N.

+if DEBUG_INFO
+
config DEBUG_INFO_REDUCED
bool "Reduce debugging information"
- depends on DEBUG_INFO
help
If you say Y here gcc is instructed to generate less debugging
information for structure types. This means that tools that
@@ -227,7 +228,6 @@ config DEBUG_INFO_REDUCED

config DEBUG_INFO_COMPRESSED
bool "Compressed debugging information"
- depends on DEBUG_INFO
depends on $(cc-option,-gz=zlib)
depends on $(ld-option,--compress-debug-sections=zlib)
help
@@ -243,7 +243,6 @@ config DEBUG_INFO_COMPRESSED

config DEBUG_INFO_SPLIT
bool "Produce split debuginfo in .dwo files"
- depends on DEBUG_INFO
depends on $(cc-option,-gsplit-dwarf)
help
Generate debug info into separate .dwo files. This significantly
@@ -259,7 +258,6 @@ config DEBUG_INFO_SPLIT

config DEBUG_INFO_DWARF4
bool "Generate dwarf4 debuginfo"
- depends on DEBUG_INFO
depends on $(cc-option,-gdwarf-4)
help
Generate dwarf4 debug info. This requires recent versions
@@ -269,7 +267,6 @@ config DEBUG_INFO_DWARF4

config DEBUG_INFO_BTF
bool "Generate BTF typeinfo"
- depends on DEBUG_INFO
depends on !DEBUG_INFO_SPLIT && !DEBUG_INFO_REDUCED
depends on !GCC_PLUGIN_RANDSTRUCT || COMPILE_TEST
help
@@ -279,7 +276,6 @@ config DEBUG_INFO_BTF

config GDB_SCRIPTS
bool "Provide GDB scripts for kernel debugging"
- depends on DEBUG_INFO
help
This creates the required links to GDB helper scripts in the
build directory. If you load vmlinux into gdb, the helper
@@ -288,6 +284,8 @@ config GDB_SCRIPTS
instance. See Documentation/dev-tools/gdb-kernel-debugging.rst
for further details.

+endif # DEBUG_INFO
+
config ENABLE_MUST_CHECK
bool "Enable __must_check logic"
default y
--
2.28.0