Merge tag 'kbuild-v4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - improve fixdep to coalesce consecutive slashes in dep-files

 - fix some issues of the maintainer string generation in deb-pkg script

 - remove unused CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX and clean-up
   several tools and linker scripts

 - clean-up modpost

 - allow to enable the dead code/data elimination for PowerPC in EXPERT
   mode

 - improve two coccinelle scripts for better performance

 - pass endianness and machine size flags to sparse for all architecture

 - misc fixes

* tag 'kbuild-v4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (25 commits)
  kbuild: add machine size to CHECKFLAGS
  kbuild: add endianness flag to CHEKCFLAGS
  kbuild: $(CHECK) doesnt need NOSTDINC_FLAGS twice
  scripts: Fixed printf format mismatch
  scripts/tags.sh: use `find` for $ALLSOURCE_ARCHS generation
  coccinelle: deref_null: improve performance
  coccinelle: mini_lock: improve performance
  powerpc: Allow LD_DEAD_CODE_DATA_ELIMINATION to be selected
  kbuild: Allow LD_DEAD_CODE_DATA_ELIMINATION to be selectable if enabled
  kbuild: LD_DEAD_CODE_DATA_ELIMINATION no -ffunction-sections/-fdata-sections for module build
  kbuild: Fix asm-generic/vmlinux.lds.h for LD_DEAD_CODE_DATA_ELIMINATION
  modpost: constify *modname function argument where possible
  modpost: remove redundant is_vmlinux() test
  modpost: use strstarts() helper more widely
  modpost: pass struct elf_info pointer to get_modinfo()
  checkpatch: remove VMLINUX_SYMBOL() check
  vmlinux.lds.h: remove no-op macro VMLINUX_SYMBOL()
  kbuild: remove CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX
  export.h: remove code for prefixing symbols with underscore
  depmod.sh: remove symbol prefix support
  ...

1 files changed, 27 insertions, 0 deletions

diff --git a/init/Kconfig b/init/Kconfig
index 18b151f0ddc1..829a4c1117f2 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1038,6 +1038,33 @@ config CC_OPTIMIZE_FOR_SIZE
 
 endchoice
 
+config HAVE_LD_DEAD_CODE_DATA_ELIMINATION
+	bool
+	help
+	  This requires that the arch annotates or otherwise protects
+	  its external entry points from being discarded. Linker scripts
+	  must also merge .text.*, .data.*, and .bss.* correctly into
+	  output sections. Care must be taken not to pull in unrelated
+	  sections (e.g., '.text.init'). Typically '.' in section names
+	  is used to distinguish them from label names / C identifiers.
+
+config LD_DEAD_CODE_DATA_ELIMINATION
+	bool "Dead code and data elimination (EXPERIMENTAL)"
+	depends on HAVE_LD_DEAD_CODE_DATA_ELIMINATION
+	depends on EXPERT
+	help
+	  Select this if the architecture wants to do dead code and
+	  data elimination with the linker by compiling with
+	  -ffunction-sections -fdata-sections, and linking with
+	  --gc-sections.
+
+	  This can reduce on disk and in-memory size of the kernel
+	  code and static data, particularly for small configs and
+	  on small systems. This has the possibility of introducing
+	  silently broken kernel if the required annotations are not
+	  present. This option is not well tested yet, so use at your
+	  own risk.
+
 config SYSCTL
 	bool