diff options
Diffstat (limited to 'xen/Rules.mk')
| -rw-r--r-- | xen/Rules.mk | 39 |
1 files changed, 36 insertions, 3 deletions
diff --git a/xen/Rules.mk b/xen/Rules.mk index 59d0dc7c31..9a9829bcb3 100644 --- a/xen/Rules.mk +++ b/xen/Rules.mk @@ -9,6 +9,8 @@ perfc_arrays ?= n lock_profile ?= n crash_debug ?= n frame_pointer ?= n +clang ?= n +lto ?= n XEN_ROOT=$(BASEDIR)/.. include $(XEN_ROOT)/Config.mk @@ -75,7 +77,8 @@ CFLAGS += $(CFLAGS-y) # Most CFLAGS are safe for assembly files: # -std=gnu{89,99} gets confused by #-prefixed end-of-line comments -AFLAGS += $(AFLAGS-y) $(filter-out -std=gnu%,$(CFLAGS)) +# -flto makes no sense and annoys clang +AFLAGS += $(AFLAGS-y) $(filter-out -std=gnu%,$(filter-out -flto,$(CFLAGS))) # LDFLAGS are only passed directly to $(LD) LDFLAGS += $(LDFLAGS_DIRECT) @@ -86,18 +89,45 @@ include Makefile subdir-n := $(patsubst %,%/,$(patsubst %/,%,$(subdir-n) $(subdir-))) subdir-y := $(patsubst %,%/,$(patsubst %/,%,$(subdir-y))) -# Add explicitly declared subdirectories to the object list. +# Add explicitly declared subdirectories to the object lists. obj-y += $(patsubst %/,%/built_in.o,$(subdir-y)) -# Add implicitly declared subdirectories (in the object list) to the +# Add implicitly declared subdirectories (in the object lists) to the # subdirectory list, and rewrite the object-list entry. subdir-y += $(filter %/,$(obj-y)) obj-y := $(patsubst %/,%/built-in.o,$(obj-y)) subdir-all := $(subdir-y) $(subdir-n) +ifeq ($(lto),y) +# Would like to handle all object files as bitcode, but objects made from +# pure asm are in a different format and have to be collected separately. +# Mirror the directory tree, collecting them as built_in_bin.o. +# If there are no binary objects in a given directory, make a dummy .o +obj-bin-y += $(patsubst %/built_in.o,%/built_in_bin.o,$(filter %/built_in.o,$(obj-y))) +else +# For a non-LTO build, bundle obj-bin targets in with the normal objs. +obj-y += $(obj-bin-y) +obj-bin-y := +endif + built_in.o: $(obj-y) +ifeq ($(obj-y),) + $(CC) $(CFLAGS) -c -x c /dev/null -o $@ +else +ifeq ($(lto),y) + $(LD_LTO) -r -o $@ $^ +else + $(LD) $(LDFLAGS) -r -o $@ $^ +endif +endif + +built_in_bin.o: $(obj-bin-y) +ifeq ($(obj-bin-y),) + $(CC) $(AFLAGS) -c -x assembler /dev/null -o $@ +else $(LD) $(LDFLAGS) -r -o $@ $^ +endif # Force execution of pattern rules (for which PHONY cannot be directly used). .PHONY: FORCE @@ -106,6 +136,9 @@ FORCE: %/built_in.o: FORCE $(MAKE) -f $(BASEDIR)/Rules.mk -C $* built_in.o +%/built_in_bin.o: FORCE + $(MAKE) -f $(BASEDIR)/Rules.mk -C $* built_in_bin.o + .PHONY: clean clean:: $(addprefix _clean_, $(subdir-all)) rm -f *.o *~ core $(DEPS) |