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-rw-r--r--scripts/Makefile.build129
1 files changed, 115 insertions, 14 deletions
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index abfd4f4b66dd..d41c72a51043 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -176,6 +176,14 @@ 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)
@@ -200,6 +208,23 @@ else
cmd_cc_o_c = $(CC) $(c_flags) -c -o $(@D)/.tmp_$(@F) $<
+ifdef CONFIG_LTO_CLANG
+# Generate .o.symversions files for each .o with exported symbols, and link these
+# to the kernel and/or modules at the end.
+cmd_modversions_c = \
+ if $(OBJDUMP) -h $(@D)/.tmp_$(@F) >/dev/null 2>/dev/null; then \
+ if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \
+ $(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
+ > $(@D)/$(@F).symversions; \
+ fi; \
+ else \
+ if $(LLVM_DIS) -o=- $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \
+ $(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
+ > $(@D)/$(@F).symversions; \
+ fi; \
+ fi; \
+ mv -f $(@D)/.tmp_$(@F) $@;
+else
cmd_modversions_c = \
if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \
$(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
@@ -212,12 +237,19 @@ cmd_modversions_c = \
mv -f $(@D)/.tmp_$(@F) $@; \
fi;
endif
+endif
ifdef CONFIG_FTRACE_MCOUNT_RECORD
ifdef BUILD_C_RECORDMCOUNT
ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
RECORDMCOUNT_FLAGS = -w
endif
+
+ifdef CONFIG_LTO_CLANG
+# With LTO, we postpone running recordmcount until after the LTO link step, so
+# let's export the parameters for the link script.
+export RECORDMCOUNT_FLAGS
+else
# Due to recursion, we must skip empty.o.
# The empty.o file is created in the make process in order to determine
# the target endianness and word size. It is made before all other C
@@ -226,23 +258,29 @@ sub_cmd_record_mcount = \
if [ $(@) != "scripts/mod/empty.o" ]; then \
$(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)"; \
fi;
+endif
+
recordmcount_source := $(srctree)/scripts/recordmcount.c \
$(srctree)/scripts/recordmcount.h
-else
+else # !BUILD_C_RECORDMCOUNT
sub_cmd_record_mcount = set -e ; perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
"$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
"$(if $(CONFIG_64BIT),64,32)" \
"$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CFLAGS)" \
"$(LD)" "$(NM)" "$(RM)" "$(MV)" \
"$(if $(part-of-module),1,0)" "$(@)";
+
recordmcount_source := $(srctree)/scripts/recordmcount.pl
-endif
+endif # BUILD_C_RECORDMCOUNT
+
+ifndef CONFIG_LTO_CLANG
cmd_record_mcount = \
if [ "$(findstring $(CC_FLAGS_FTRACE),$(_c_flags))" = \
"$(CC_FLAGS_FTRACE)" ]; then \
$(sub_cmd_record_mcount) \
fi;
endif
+endif # CONFIG_FTRACE_MCOUNT_RECORD
ifdef CONFIG_STACK_VALIDATION
ifneq ($(SKIP_STACK_VALIDATION),1)
@@ -429,9 +467,30 @@ $(sort $(subdir-obj-y)): $(subdir-ym) ;
#
ifdef builtin-target
+ifdef CONFIG_LTO_CLANG
+ ifdef CONFIG_MODVERSIONS
+ # combine symversions for later processing
+ update_lto_symversions = \
+ rm -f $@.symversions; \
+ for i in $(filter-out FORCE,$^); do \
+ if [ -f $$i.symversions ]; then \
+ cat $$i.symversions \
+ >> $@.symversions; \
+ fi; \
+ done;
+ endif
+ # rebuild the symbol table with llvm-ar to include IR files
+ update_lto_symtable = ; \
+ mv -f $@ $@.tmp; \
+ $(LLVM_AR) rcsT$(KBUILD_ARFLAGS) $@ \
+ $$($(AR) t $@.tmp); \
+ rm -f $@.tmp
+endif
+
ifdef CONFIG_THIN_ARCHIVES
- cmd_make_builtin = rm -f $@; $(AR) rcST$(KBUILD_ARFLAGS)
- cmd_make_empty_builtin = rm -f $@; $(AR) rcST$(KBUILD_ARFLAGS)
+ cmd_make_builtin = $(update_lto_symversions) \
+ rm -f $@; $(AR) rcSTP$(KBUILD_ARFLAGS)
+ cmd_make_empty_builtin = rm -f $@; $(AR) rcSTP$(KBUILD_ARFLAGS)
quiet_cmd_link_o_target = AR $@
else
cmd_make_builtin = $(LD) $(ld_flags) -r -o
@@ -471,7 +530,11 @@ ifdef lib-target
quiet_cmd_link_l_target = AR $@
ifdef CONFIG_THIN_ARCHIVES
- cmd_link_l_target = rm -f $@; $(AR) rcsT$(KBUILD_ARFLAGS) $@ $(lib-y)
+ cmd_link_l_target = \
+ $(update_lto_symversions) \
+ rm -f $@; \
+ $(AR) rcsTP$(KBUILD_ARFLAGS) $@ $(lib-y) \
+ $(update_lto_symtable)
else
cmd_link_l_target = rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS) $@ $(lib-y)
endif
@@ -489,14 +552,36 @@ else
ref_prefix = EXTERN(
endif
-quiet_cmd_export_list = EXPORTS $@
-cmd_export_list = $(OBJDUMP) -h $< | \
- sed -ne '/___ksymtab/{s/.*+/$(ref_prefix)/;s/ .*/)/;p}' >$(ksyms-lds);\
- rm -f $(dummy-object);\
- $(AR) rcs$(KBUILD_ARFLAGS) $(dummy-object);\
+filter_export_list = sed -ne '/___ksymtab/s/.*+\([^ "]*\).*/$(ref_prefix)\1)/p'
+link_export_list = rm -f $(dummy-object);\
+ echo | $(CC) $(a_flags) -c -o $(dummy-object) -x assembler -;\
$(LD) $(ld_flags) -r -o $@ -T $(ksyms-lds) $(dummy-object);\
rm $(dummy-object) $(ksyms-lds)
+quiet_cmd_export_list = EXPORTS $@
+
+ifdef CONFIG_LTO_CLANG
+# objdump doesn't understand IR files and llvm-dis doesn't support archives,
+# so we'll walk through each file in the archive separately
+cmd_export_list = \
+ rm -f $(ksyms-lds); \
+ for o in $$($(AR) t $<); do \
+ if $(OBJDUMP) -h $$o >/dev/null 2>/dev/null; then \
+ $(OBJDUMP) -h $$o | \
+ $(filter_export_list) \
+ >>$(ksyms-lds); \
+ else \
+ $(LLVM_DIS) -o=- $$o | \
+ $(filter_export_list) \
+ >>$(ksyms-lds); \
+ fi; \
+ done; \
+ $(link_export_list)
+else
+cmd_export_list = $(OBJDUMP) -h $< | $(filter_export_list) >$(ksyms-lds); \
+ $(link_export_list)
+endif
+
$(obj)/lib-ksyms.o: $(lib-target) FORCE
$(call if_changed,export_list)
@@ -520,20 +605,36 @@ $($(subst $(obj)/,,$(@:.o=-objs))) \
$($(subst $(obj)/,,$(@:.o=-y))) \
$($(subst $(obj)/,,$(@:.o=-m)))), $^)
-quiet_cmd_link_multi-y = LD $@
-cmd_link_multi-y = $(LD) $(ld_flags) -r -o $@ $(link_multi_deps) $(cmd_secanalysis)
+cmd_link_multi-link = $(LD) $(ld_flags) -r -o $@ $(link_multi_deps) $(cmd_secanalysis)
+
+ifdef CONFIG_THIN_ARCHIVES
+ quiet_cmd_link_multi-y = AR $@
+ cmd_link_multi-y = $(update_lto_symversions) \
+ rm -f $@; $(AR) rcSTP$(KBUILD_ARFLAGS) $@ $(link_multi_deps) \
+ $(update_lto_symtable)
+else
+ quiet_cmd_link_multi-y = LD $@
+ cmd_link_multi-y = $(cmd_link_multi-link)
+endif
quiet_cmd_link_multi-m = LD [M] $@
-cmd_link_multi-m = $(cmd_link_multi-y)
+
+ifdef CONFIG_LTO_CLANG
+ # don't compile IR until needed
+ cmd_link_multi-m = $(cmd_link_multi-y)
+else
+ cmd_link_multi-m = $(cmd_link_multi-link)
+endif
$(multi-used-y): FORCE
$(call if_changed,link_multi-y)
-$(call multi_depend, $(multi-used-y), .o, -objs -y)
$(multi-used-m): FORCE
$(call if_changed,link_multi-m)
@{ echo $(@:.o=.ko); echo $(link_multi_deps); \
$(cmd_undef_syms); } > $(MODVERDIR)/$(@F:.o=.mod)
+
+$(call multi_depend, $(multi-used-y), .o, -objs -y)
$(call multi_depend, $(multi-used-m), .o, -objs -y -m)
targets += $(multi-used-y) $(multi-used-m)
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-11 17:35:42 +0000