[PATCH v7 1/2] Kbuild: make DWARF version a choice
From: Nick Desaulniers <hidden>
Date: 2021-01-30 01:09:20
Also in:
linux-kbuild, lkml
Subsystem:
kernel build + files below scripts/ (unless maintained elsewhere), library code, the rest · Maintainers:
Nathan Chancellor, Nicolas Schier, Andrew Morton, Linus Torvalds
Modifies CONFIG_DEBUG_INFO_DWARF4 to be a member of a choice which is the default. Does so in a way that's forward compatible with existing configs, and makes adding future versions more straightforward. GCC since ~4.8 has defaulted to this DWARF version implicitly. Suggested-by: Arvind Sankar <redacted> Suggested-by: Fangrui Song <redacted> Suggested-by: Nathan Chancellor <nathan@kernel.org> Suggested-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Nick Desaulniers <redacted> --- Makefile | 5 ++--- lib/Kconfig.debug | 16 +++++++++++----- 2 files changed, 13 insertions(+), 8 deletions(-)
diff --git a/Makefile b/Makefile
index 95ab9856f357..d2b4980807e0 100644
--- a/Makefile
+++ b/Makefile@@ -830,9 +830,8 @@ 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_DWARF4) := 4 +DEBUG_CFLAGS += -gdwarf-$(dwarf-version-y) 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 e906ea906cb7..94c1a7ed6306 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug@@ -256,13 +256,19 @@ 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_DWARF4 - bool "Generate dwarf4 debuginfo" + bool "Generate DWARF Version 4 debuginfo" 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"
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2.30.0.365.g02bc693789-goog