Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild

Pull kbuild updates from Michal Marek:
 - make clean also considers $(extra-m) and $(extra-) to be consistent
 - cleanup and fixes in scripts/Makefile.host
 - allow to override the name of the Python 2 executable with make
   PYTHON=... (only needed for ia64 in practice)
 - option to split debugingo into *.dwo files to save disk space if the
   compiler supports it (CONFIG_DEBUG_INFO_SPLIT)
 - option to use dwarf4 debuginfo if the compiler supports it
   (CONFIG_DEBUG_INFO_DWARF4)
 - fix for disabling certain warnings with clang
 - fix for unneeded rebuild with dash when a command contains
   backslashes

* 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
  kbuild: Fix handling of backslashes in *.cmd files
  kbuild, LLVMLinux: Supress warnings unless W=1-3
  Kbuild: Add a option to enable dwarf4 v2
  kbuild: Support split debug info v4
  kbuild: allow to override Python command name
  kbuild: clean-up and bug fix of scripts/Makefile.host
  kbuild: clean up scripts/Makefile.host
  kbuild: drop shared library support from Makefile.host
  kbuild: fix a bug of C++ host program handling
  kbuild: fix a typo in scripts/Makefile.host
  scripts/Makefile.clean: clean also $(extra-m) and $(extra-)

1 files changed, 24 insertions, 0 deletions

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index cb45f59685e6..07c28323f88f 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -143,6 +143,30 @@ config DEBUG_INFO_REDUCED
           DEBUG_INFO build and compile times are reduced too.
           Only works with newer gcc versions.
 
+config DEBUG_INFO_SPLIT
+        bool "Produce split debuginfo in .dwo files"
+        depends on DEBUG_INFO
+        help
+          Generate debug info into separate .dwo files. This significantly
+          reduces the build directory size for builds with DEBUG_INFO,
+          because it stores the information only once on disk in .dwo
+          files instead of multiple times in object files and executables.
+          In addition the debug information is also compressed.
+
+          Requires recent gcc (4.7+) and recent gdb/binutils.
+          Any tool that packages or reads debug information would need
+          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