commit 85ab13ffcc69fbe93c3a9d38857795cba79a4c35
author Vinícius Tinti <viniciustinti@gmail.com> Mon Apr 24 13:04:58 2017 -0700
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> Fri Nov 23 08:20:35 2018 +0100
tree e1a16e276f9fdd0c891af4b178527b34308c1799
parent d438cec0737451e3615c4665592b6df0858de41a

kbuild: Add support to generate LLVM assembly files

commit 433db3e260bc8134d4a46ddf20b3668937e12556 upstream.

Add rules to kbuild in order to generate LLVM assembly files with the .ll
extension when using clang.

  # from c code
  make CC=clang kernel/pid.ll

Signed-off-by: Vinícius Tinti <viniciustinti@gmail.com>
Signed-off-by: Behan Webster <behanw@converseincode.com>
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

scripts/Makefile.build

diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index abfd4f4..6228a83 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -176,6 +176,14 @@
 $(obj)/%.symtypes : $(src)/%.c FORCE
 	$(call cmd,cc_symtypes_c)
 
+# LLVM assembly
+# Generate .ll files from .c
+quiet_cmd_cc_ll_c = CC $(quiet_modtag)  $@
+      cmd_cc_ll_c = $(CC) $(c_flags) -emit-llvm -S -o $@ $<
+
+$(obj)/%.ll: $(src)/%.c FORCE
+	$(call if_changed_dep,cc_ll_c)
+
 # C (.c) files
 # The C file is compiled and updated dependency information is generated.
 # (See cmd_cc_o_c + relevant part of rule_cc_o_c)