Re: [PATCH v5 2/3] Kbuild: make DWARF version a choice
From: Sedat Dilek <hidden>
Date: 2021-01-15 21:43:33
Also in:
linux-kbuild, lkml
On Fri, Jan 15, 2021 at 10:06 PM Nick Desaulniers [off-list ref] wrote:
quoted hunk ↗ jump to hunk
Modifies CONFIG_DEBUG_INFO_DWARF4 to be a member of a choice. Adds an explicit CONFIG_DEBUG_INFO_DWARF2, which is the default. Does so in a way that's forward compatible with existing configs, and makes adding future versions more straightforward. Suggested-by: Arvind Sankar <redacted> Suggested-by: Fangrui Song <redacted> Suggested-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Nick Desaulniers <redacted> --- Makefile | 13 ++++++------- lib/Kconfig.debug | 21 ++++++++++++++++----- 2 files changed, 22 insertions(+), 12 deletions(-)diff --git a/Makefile b/Makefile index d49c3f39ceb4..4eb3bf7ee974 100644 --- a/Makefile +++ b/Makefile@@ -826,13 +826,12 @@ else DEBUG_CFLAGS += -g endif -ifneq ($(LLVM_IAS),1) -KBUILD_AFLAGS += -Wa,-gdwarf-2 -endif - -ifdef CONFIG_DEBUG_INFO_DWARF4 -DEBUG_CFLAGS += -gdwarf-4 -endif +dwarf-version-$(CONFIG_DEBUG_INFO_DWARF2) := 2 +dwarf-version-$(CONFIG_DEBUG_INFO_DWARF4) := 4 +DEBUG_CFLAGS += -gdwarf-$(dwarf-version-y) +# Binutils 2.35+ required for -gdwarf-4+ support. +dwarf-aflag := $(call as-option,-Wa$(comma)-gdwarf-$(dwarf-version-y)) +KBUILD_AFLAGS += $(dwarf-aflag) ifdef CONFIG_DEBUG_INFO_REDUCED DEBUG_CFLAGS += $(call cc-option, -femit-struct-debug-baseonly) \diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index dd7d8d35b2a5..e80770fac4f0 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug@@ -256,13 +256,24 @@ config DEBUG_INFO_SPLIT to know about the .dwo files and include them. Incompatible with older versions of ccache. +choice + prompt "DWARF version"
Here you use "DWARF version" so keep this for v2 and v4.
+ help + Which version of DWARF debug info to emit. + +config DEBUG_INFO_DWARF2 + bool "Generate DWARF Version 2 debuginfo"
s/DWARF Version/DWARF version
+ help + Generate DWARF v2 debug info. + config DEBUG_INFO_DWARF4 - bool "Generate dwarf4 debuginfo" + bool "Generate DWARF Version 4 debuginfo"
Same here: s/DWARF Version/DWARF version - Sedat -
help
- Generate dwarf4 debug info. This requires recent versions
- of gcc and gdb. It makes the debug information larger.
- But it significantly improves the success of resolving
- variables in gdb on optimized code.
+ Generate DWARF v4 debug info. This requires gcc 4.5+ and gdb 7.0+.
+ It makes the debug information larger, but it significantly
+ improves the success of resolving variables in gdb on optimized code.
+
+endchoice # "DWARF version"
config DEBUG_INFO_BTF
bool "Generate BTF typeinfo"
--
2.30.0.284.gd98b1dd5eaa7-goog