From bfaf2dd3509bc73bf4a4cea0e72472755ed860e2 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Wed, 30 Jul 2014 20:50:19 +0200 Subject: [PATCH] Kbuild: Add a option to enable dwarf4 v2 I found that a lot of unresolvable variables when using gdb on the kernel become resolvable when dwarf4 is enabled. So add a Kconfig flag to enable it. It definitely increases the debug information size, but on the other hand this isn't so bad when debug fusion is used. v2: Use cc-option Signed-off-by: Andi Kleen Acked-by: Sam Ravnborg Signed-off-by: Michal Marek --- Makefile | 3 +++ lib/Kconfig.debug | 9 +++++++++ 2 files changed, 12 insertions(+) diff --git a/Makefile b/Makefile index e5a2694..2fd21a5 100644 --- a/Makefile +++ b/Makefile @@ -691,6 +691,9 @@ KBUILD_CFLAGS += -g endif KBUILD_AFLAGS += -Wa,-gdwarf-2 endif +ifdef CONFIG_DEBUG_INFO_DWARF4 +KBUILD_CFLAGS += $(call cc-option, -gdwarf-4,) +endif ifdef CONFIG_DEBUG_INFO_REDUCED KBUILD_CFLAGS += $(call cc-option, -femit-struct-debug-baseonly) \ diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 910355d..d70f203 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -158,6 +158,15 @@ config DEBUG_INFO_SPLIT to know about the .dwo files and include them. Incompatible with older versions of ccache. +config DEBUG_INFO_DWARF4 + bool "Generate dwarf4 debuginfo" + depends on DEBUG_INFO + 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. + config ENABLE_WARN_DEPRECATED bool "Enable __deprecated logic" default y -- 2.7.4