1 files changed, 112 insertions, 0 deletions
diff --git a/mk/cores.mk b/mk/cores.mk
new file mode 100644
index 0000000..7ce2e47
--- /dev/null
+++ b/mk/cores.mk
@@ -0,0 +1,112 @@
+here = $(if $(mod_path),$(mod_path)/)
+mod_path :=
+subdir_stack :=
+
+unknown_core = $(error unknown core '$(1)')
+
+all_cores :=
+all_stamps :=
+
+top_stamp = $(call core_stamp,$(rule_top))
+core_stamp = $(obj)/deps/$(core_info/$(1)/path)/stamp
+
+core_paths = \
+  $(patsubst /%,%, \
+    $(patsubst /,., \
+      $(abspath \
+        $(let prefix,$(core_info/$(1)/workdir), \
+          $(addprefix /$(if $(prefix),$(prefix)/),$(core_info/$(1)/$(2)))))))
+
+define add_core
+  this := core_info/$(1)
+
+  ifneq (,$$($$(this)/path))
+    $$(error multiple definitions of core '$(1)': '$$($$(this)/path)' and '$(2)')
+  else ifneq (,$$(core_path/$(2)))
+    $$(error multiple cores under path '$(2)')
+  endif
+
+  $$(this)/path := $(2)
+  $$(this)/mod_file := $$(mod_file)
+  $$(this)/workdir := $$(mod_path)
+
+  $$(eval $$(call $(3)))
+
+  this :=
+  all_cores += $(1)
+  core_path/$(2) := $(1)
+endef
+
+define add_core_subdir
+  core :=
+  cores :=
+  subdirs :=
+
+  subdir_stack += $$(mod_path)
+  mod_path := $$(here)$(1)
+  mod_file := $$(here)mod.mk
+
+  include $$(mod_file)
+
+  $$(if $$(core), \
+    $$(eval $$(call add_core,$(notdir $(1)),$$(mod_path),core)))
+
+  $$(foreach core,$$(cores), \
+    $$(eval $$(call add_core,$$(core),$$(here)$$(core),core/$$(core))))
+
+  $$(foreach subdir,$$(subdirs), \
+    $$(eval $$(call add_core_subdir,$$(subdir))))
+
+  mod_path := $$(lastword $$(subdir_stack))
+  subdir_stack := $$(filter-out $$(mod_path),$$(subdir_stack))
+endef
+
+define setup_dep_tree
+  $$(foreach core,$$(all_cores), \
+    $$(eval $$(call defer,dep_tree/$$(core),$$$$(call get_core_deps,$$(core)))))
+endef
+
+define setup_stamp_rules
+  $$(foreach core,$$(all_cores), \
+    $$(let stamp,$$(call core_stamp,$$(core)), \
+      $$(stamp) \
+      $$(eval $$(call add_core_stamp,$$(core),$$(stamp))))): $$(build_makefiles) | $$(obj)
+endef
+
+define add_core_stamp
+  $(2): $$(core_info/$(1)/mod_file) \
+        $$(foreach dep,$$(core_info/$(1)/deps),$$(call core_stamp,$$(dep)))
+
+  all_stamps += $(2)
+endef
+
+define get_core_deps
+  dep_tree/$(1) :=
+
+  $$(foreach dep,$$(core_info/$(1)/deps), \
+    $$(if $$(core_info/$$(dep)/path),,$$(call unknown_core,$$(dep))) \
+    $$(eval dep_tree/$(1) := \
+      $$(dep_tree/$$(dep)) $$(filter-out $$(dep_tree/$$(dep)),$$(dep_tree/$(1)))))
+
+  dep_tree/$(1) := $$(strip $$(dep_tree/$(1)))
+  dep_tree/$(1) += $(1)
+endef
+
+map_core_deps = \
+  $(if $(findstring undefined,$(origin $(1)_deps/$(2))), \
+    $(eval $(call merge_mapped_deps,$(1),$(2)))) \
+  $($(1)_deps/$(2))
+
+define merge_mapped_deps
+  $(1)_deps/$(2) := $$(core_info/$(2)/$(1))
+
+  $$(foreach dep,$$(core_info/$(2)/deps), \
+    $$(eval $(1)_deps/$(2) := \
+      $$(let mapped_dep,$$(call map_core_deps,$(1),$$(dep)), \
+        $$(mapped_dep) $$(filter-out $$(mapped_dep),$$($(1)_deps/$(2))))))
+endef
+
+define finish_stamp_rules
+  $$(all_stamps):
+	@mkdir -p $$$$(dirname $$@) && touch $$@
+endef