mk: initial commit

This is a complete overhaul of the build system. This new
implementations upports many new features and is very extensible.

1 files changed, 45 insertions, 0 deletions

diff --git a/mk/target.mk b/mk/target.mk
new file mode 100644
index 0000000..d28c2e2
--- /dev/null
+++ b/mk/target.mk
@@ -0,0 +1,45 @@
+target_var = $(1)/$(rule_target)/$(rule_top)
+per_target = $($(call target_var,$(1)))
+
+rule_top_path = $(core_info/$(rule_top)/path)
+
+define target_entrypoint
+  $(1): rule_top := $$(rule_top)
+  $(1): rule_target := $$(rule_target)
+endef
+
+define check_target
+  ifneq ($$(target),$$(findstring $$(target),$$(targets)))
+    $$(error bad target '$$(target)')
+  endif
+endef
+
+define setup_submake_rules
+  .PHONY: $$(targets)
+
+  other_targets := $$(filter-out $$(target),$$(targets))
+
+  $$(foreach t,$$(targets),$$(eval $$(call top_rule,$$(t))))
+
+  ifeq (,$$(target))
+    $$(foreach other,$$(other_targets), \
+      $$(foreach core,$$(all_cores), \
+        $$(eval $$(call submake_rule,$$(other),$$(core)))))
+  else
+    $$(foreach core,$$(filter-out $$(top),$$(all_cores)), \
+      $$(eval $$(call submake_rule,$$(target),$$(core))))
+  endif
+endef
+
+define top_rule
+  $(1): $$(top_path)/$(1)
+endef
+
+define submake_rule
+  path := $$(core_info/$(2)/path)/$(1)
+
+  .PHONY: $$(path)
+
+  $$(path):
+	+$$(MAKE) --no-print-directory target=$(1) top=$(2) $$@
+endef