[PATCH] kbuild: add option to set max level of debug info

[Dmitrii Bundin <dmitrii.bundin.a@gmail.com>]

When compiling with -g3 option and debugging with gdb it provides some
extra abilities like macro expand, info macro etc... It's sometimes
useful to unerstand behavior of complicated macros.

Signed-off-by: Dmitrii Bundin <dmitrii.bundin.a@gmail.com>
---
 lib/Kconfig.debug      | 9 +++++++++
 scripts/Makefile.debug | 2 ++
 2 files changed, 11 insertions(+)

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 2e24db4bff19..1e8bef3e2a95 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -304,6 +304,15 @@ config DEBUG_INFO_REDUCED
 	  DEBUG_INFO build and compile times are reduced too.
 	  Only works with newer gcc versions.
 
+config DEBUG_INFO_MAXLEVEL
+	bool "Maximum debug information level"
+	depends on !DEBUG_INFO_REDUCED
+	default n
+	help
+	  Sets the maximum level of debug information compilers may generate
+	  (-g3). Enabling this option will require significantly more disk space
+	  and increase built time, but it's useful for debugging purposes.
+
 config DEBUG_INFO_COMPRESSED
 	bool "Compressed debugging information"
 	depends on $(cc-option,-gz=zlib)
diff --git a/scripts/Makefile.debug b/scripts/Makefile.debug
index 9f39b0130551..7e1d8beecfc4 100644
--- a/scripts/Makefile.debug
+++ b/scripts/Makefile.debug
@@ -2,6 +2,8 @@ DEBUG_CFLAGS	:=
 
 ifdef CONFIG_DEBUG_INFO_SPLIT
 DEBUG_CFLAGS	+= -gsplit-dwarf
+else ifdef CONFIG_DEBUG_INFO_MAXLEVEL
+DEBUG_CFLAGS	+= -g3
 else
 DEBUG_CFLAGS	+= -g
 endif
-- 
2.17.1