Re: [PATCH v3 1/2] Kbuild: make DWARF version a choice
From: Nathan Chancellor <hidden>
Date: 2021-01-04 23:10:47
Also in:
lkml
On Thu, Dec 03, 2020 at 05:11:26PM -0800, 'Nick Desaulniers' via Clang Built Linux wrote:
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: Fangrui Song <redacted> Suggested-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nathan Chancellor <redacted>
quoted hunk ↗ jump to hunk
--- Makefile | 14 ++++++++------ lib/Kconfig.debug | 21 ++++++++++++++++----- 2 files changed, 24 insertions(+), 11 deletions(-)diff --git a/Makefile b/Makefile index a2ded5029084..2430e1ee7c44 100644 --- a/Makefile +++ b/Makefile@@ -826,12 +826,14 @@ else DEBUG_CFLAGS += -g endif -ifneq ($(LLVM_IAS),1) -KBUILD_AFLAGS += -Wa,-gdwarf-2 -endif - -ifdef CONFIG_DEBUG_INFO_DWARF4 -DEBUG_CFLAGS += -gdwarf-4 +dwarf-version-$(CONFIG_DEBUG_INFO_DWARF2) := 2 +dwarf-version-$(CONFIG_DEBUG_INFO_DWARF4) := 4 +DEBUG_CFLAGS += -gdwarf-$(dwarf-version-y) +ifneq ($(dwarf-version-y)$(LLVM_IAS),21) +# Binutils 2.35+ required for -gdwarf-4+ support. +dwarf-aflag := $(call as-option,-Wa$(comma)-gdwarf-$(dwarf-version-y)) +DEBUG_CFLAGS += $(dwarf-aflag) +KBUILD_AFLAGS += $(dwarf-aflag) endif ifdef CONFIG_DEBUG_INFO_REDUCEDdiff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 0c7380e36370..04719294a7a3 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug@@ -256,14 +256,25 @@ config DEBUG_INFO_SPLIT to know about the .dwo files and include them. Incompatible with older versions of ccache. +choice + prompt "DWARF version" + help + Which version of DWARF debug info to emit. + +config DEBUG_INFO_DWARF2 + bool "Generate DWARF Version 2 debuginfo" + help + Generate DWARF v2 debug info. + config DEBUG_INFO_DWARF4 - bool "Generate dwarf4 debuginfo" + bool "Generate DWARF Version 4 debuginfo" depends on $(cc-option,-gdwarf-4) 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"-- 2.29.2.576.ga3fc446d84-goog