kbuild: refactor modversions build rules

Let $(CC) compile objects into normal files *.o instead of .tmp_*.o
whether CONFIG_MODVERSIONS is enabled or not. With this, the input
file for objtool is always *.o so objtool_o can go away.

I guess the reason of using .tmp_*.o for intermediate objects was
to avoid leaving incomplete *.o file (, whose timestamp says it is
up-to-date) when the genksyms tool failed for some reasons.

It no longer matters because any targets are deleted on errors since
commit 9c2af1c7377a ("kbuild: add .DELETE_ON_ERROR special target").

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

1 files changed, 17 insertions, 37 deletions

diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 91b63ba926fc..cdb25d163b42 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -154,35 +154,30 @@ $(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 $@ $<
 
-ifndef CONFIG_MODVERSIONS
-cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
-
-else
+ifdef CONFIG_MODVERSIONS
 # When module versioning is enabled the following steps are executed:
-# o compile a .tmp_<file>.o from <file>.c
-# o if .tmp_<file>.o doesn't contain a __ksymtab version, i.e. does
-#   not export symbols, we just rename .tmp_<file>.o to <file>.o and
-#   are done.
+# o compile a <file>.o from <file>.c
+# o if <file>.o doesn't contain a __ksymtab version, i.e. does
+#   not export symbols, it's done.
 # o otherwise, we calculate symbol versions using the good old
 #   genksyms on the preprocessed source and postprocess them in a way
 #   that they are usable as a linker script
-# o generate <file>.o from .tmp_<file>.o using the linker to
+# o generate .tmp_<file>.o from <file>.o using the linker to
 #   replace the unresolved symbols __crc_exported_symbol with
 #   the actual value of the checksum generated by genksyms
-
-cmd_cc_o_c = $(CC) $(c_flags) -c -o $(@D)/.tmp_$(@F) $<
+# o remove .tmp_<file>.o to <file>.o
 
 cmd_modversions_c =                                                             \
-        if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then             \
+        if $(OBJDUMP) -h $@ | grep -q __ksymtab; then                           \
                 $(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes))  \
                     > $(@D)/.tmp_$(@F:.o=.ver);                                 \
                                                                                 \
-                $(LD) $(KBUILD_LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F)               \
+                $(LD) $(KBUILD_LDFLAGS) -r -o $(@D)/.tmp_$(@F) $@               \
                         -T $(@D)/.tmp_$(@F:.o=.ver);                            \
-                rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver);                \
-        else                                                                    \
                 mv -f $(@D)/.tmp_$(@F) $@;                                      \
+                rm -f $(@D)/.tmp_$(@F:.o=.ver);                                 \
         fi;
 endif
 
@@ -241,19 +236,12 @@ ifneq ($(RETPOLINE_CFLAGS),)
 endif
 endif
 
-
-ifdef CONFIG_MODVERSIONS
-objtool_o = $(@D)/.tmp_$(@F)
-else
-objtool_o = $(@)
-endif
-
 # '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_o)";)
+        $(__objtool_obj) $(objtool_args) $@;)
 objtool_obj = $(if $(patsubst y%,, \
         $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
         $(__objtool_obj))
@@ -357,34 +345,26 @@ $(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 $@ $<
 
-ifndef CONFIG_MODVERSIONS
-cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
-
-else
+ifdef CONFIG_MODVERSIONS
 
 ASM_PROTOTYPES := $(wildcard $(srctree)/arch/$(SRCARCH)/include/asm/asm-prototypes.h)
 
-ifeq ($(ASM_PROTOTYPES),)
-cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
-
-else
+ifneq ($(ASM_PROTOTYPES),)
 
 # versioning matches the C process described above, with difference that
 # we parse asm-prototypes.h C header to get function definitions.
 
-cmd_as_o_S = $(CC) $(a_flags) -c -o $(@D)/.tmp_$(@F) $<
-
 cmd_modversions_S =                                                             \
-        if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then             \
+        if $(OBJDUMP) -h $@ | grep -q __ksymtab; then                           \
                 $(call cmd_gensymtypes_S,$(KBUILD_SYMTYPES),$(@:.o=.symtypes))  \
                     > $(@D)/.tmp_$(@F:.o=.ver);                                 \
                                                                                 \
-                $(LD) $(KBUILD_LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F)               \
+                $(LD) $(KBUILD_LDFLAGS) -r -o $(@D)/.tmp_$(@F) $@               \
                         -T $(@D)/.tmp_$(@F:.o=.ver);                            \
-                rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver);                \
-        else                                                                    \
                 mv -f $(@D)/.tmp_$(@F) $@;                                      \
+                rm -f $(@D)/.tmp_$(@F:.o=.ver);                                 \
         fi;
 endif
 endif