kbuild: Add support to generate LLVM assembly files

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>
This commit is contained in:
Vinícius Tinti 2017-04-24 13:04:58 -07:00 committed by Masahiro Yamada
parent 785f11aa59
commit 433db3e260
3 changed files with 14 additions and 0 deletions

1
.gitignore vendored
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@ -33,6 +33,7 @@
*.lzo
*.patch
*.gcno
*.ll
modules.builtin
Module.symvers
*.dwo

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@ -1373,6 +1373,8 @@ help:
@echo ' (default: $$(INSTALL_MOD_PATH)/lib/firmware)'
@echo ' dir/ - Build all files in dir and below'
@echo ' dir/file.[ois] - Build specified target only'
@echo ' dir/file.ll - Build the LLVM assembly file'
@echo ' (requires compiler support for LLVM assembly generation)'
@echo ' dir/file.lst - Build specified mixed source/assembly target only'
@echo ' (requires a recent binutils and recent build (System.map))'
@echo ' dir/file.ko - Build module including final link'
@ -1557,6 +1559,7 @@ clean: $(clean-dirs)
-o -name '*.symtypes' -o -name 'modules.order' \
-o -name modules.builtin -o -name '.tmp_*.o.*' \
-o -name '*.c.[012]*.*' \
-o -name '*.ll' \
-o -name '*.gcno' \) -type f -print | xargs rm -f
# Generate tags for editors
@ -1660,6 +1663,8 @@ endif
$(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
%.symtypes: %.c prepare scripts FORCE
$(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
%.ll: %.c prepare scripts FORCE
$(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
# Modules
/: prepare scripts FORCE

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@ -177,6 +177,14 @@ cmd_cc_symtypes_c = \
$(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)