[PATCH 03/13] kbuild: detect objtool changes correctly and remove .SECONDEXPANSION
From: Masahiro Yamada <masahiroy@kernel.org>
Date: 2021-08-19 00:58:25
Also in:
lkml
Subsystem:
kernel build + files below scripts/ (unless maintained elsewhere), the rest · Maintainers:
Nathan Chancellor, Nicolas Schier, Linus Torvalds
This reverts commit 8852c5524029 ("kbuild: Fix objtool dependency for
'OBJECT_FILES_NON_STANDARD_<obj> := n'"), and fix the dependency in a
cleaner way.
Using .SECONDEXPANSION is expensive since Makefile.build is parsed
twice every time, and the escaping dollars makes the code unreadable.
Adding include/config/* as dependency is not maintainable either because
objtool_args is dependent on more CONFIG options.
A better fix is to include the objtool command in *.cmd files so any
command change is naturally detected by if_change.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
scripts/Makefile.build | 28 ++++++++++------------------
1 file changed, 10 insertions(+), 18 deletions(-)
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 31154e44c251..3e4cd1439cd4 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build@@ -155,7 +155,7 @@ $(obj)/%.ll: $(src)/%.c FORCE # (See cmd_cc_o_c + relevant part of rule_cc_o_c) quiet_cmd_cc_o_c = CC $(quiet_modtag) $@ - cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $< + cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $< $(cmd_objtool) ifdef CONFIG_MODVERSIONS # When module versioning is enabled the following steps are executed:
@@ -223,6 +223,8 @@ endif # CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT ifdef CONFIG_STACK_VALIDATION +objtool := $(objtree)/tools/objtool/objtool + # Objtool arguments are also needed for modfinal with LTO, so we define # then here to avoid duplication. objtool_args = \
@@ -237,26 +239,19 @@ objtool_args = \ ifndef CONFIG_LTO_CLANG -__objtool_obj := $(objtree)/tools/objtool/objtool - # 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory # 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file # 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file cmd_objtool = $(if $(patsubst y%,, \ $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \ - $(__objtool_obj) $(objtool_args) $@) -objtool_obj = $(if $(patsubst y%,, \ - $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \ - $(__objtool_obj)) + ; $(objtool) $(objtool_args) $@) + +# Rebuild all objects when objtool is updated +objtool_dep = $(objtool) endif # CONFIG_LTO_CLANG endif # CONFIG_STACK_VALIDATION -# Rebuild all objects when objtool changes, or is enabled/disabled. -objtool_dep = $(objtool_obj) \ - $(wildcard include/config/ORC_UNWINDER \ - include/config/STACK_VALIDATION) - ifdef CONFIG_TRIM_UNUSED_KSYMS cmd_gen_ksymdeps = \ $(CONFIG_SHELL) $(srctree)/scripts/gen_ksymdeps.sh $@ >> $(dot-target).cmd
@@ -270,7 +265,6 @@ define rule_cc_o_c $(call cmd,gen_ksymdeps) $(call cmd,checksrc) $(call cmd,checkdoc) - $(call cmd,objtool) $(call cmd,modversions_c) $(call cmd,record_mcount) endef
@@ -278,13 +272,11 @@ endef define rule_as_o_S $(call cmd_and_fixdep,as_o_S) $(call cmd,gen_ksymdeps) - $(call cmd,objtool) $(call cmd,modversions_S) endef # Built-in and composite module parts -.SECONDEXPANSION: -$(obj)/%.o: $(src)/%.c $(recordmcount_source) $$(objtool_dep) FORCE +$(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_dep) FORCE $(call if_changed_rule,cc_o_c) $(call cmd,force_checksrc)
@@ -367,7 +359,7 @@ $(obj)/%.s: $(src)/%.S FORCE $(call if_changed_dep,cpp_s_S) quiet_cmd_as_o_S = AS $(quiet_modtag) $@ - cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $< + cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $< $(cmd_objtool) ifdef CONFIG_ASM_MODVERSIONS
@@ -386,7 +378,7 @@ cmd_modversions_S = \ fi endif -$(obj)/%.o: $(src)/%.S $$(objtool_dep) FORCE +$(obj)/%.o: $(src)/%.S $(objtool_dep) FORCE $(call if_changed_rule,as_o_S) targets += $(filter-out $(subdir-builtin), $(real-obj-y))
--
2.30.2