Factor out json from soong_config.mk
Factor out the json functions from soong_config.mk, and extend them
to support maps.
Bug: 119412419
Test: no change to soong.variables
Change-Id: Ieea08fdd2aa202f60945103e3ca82538f098a942
diff --git a/core/json.mk b/core/json.mk
new file mode 100644
index 0000000..ba8ffa7
--- /dev/null
+++ b/core/json.mk
@@ -0,0 +1,35 @@
+4space :=$= $(space)$(space)$(space)$(space)
+invert_bool =$= $(if $(strip $(1)),,true)
+
+# Converts a list to a JSON list.
+# $1: List separator.
+# $2: List.
+_json_list =$= [$(if $(2),"$(subst $(1),"$(comma)",$(2))")]
+
+# Converts a space-separated list to a JSON list.
+json_list =$= $(call _json_list,$(space),$(1))
+
+# Converts a comma-separated list to a JSON list.
+csv_to_json_list =$= $(call _json_list,$(comma),$(1))
+
+# Adds or removes 4 spaces from _json_indent
+json_increase_indent =$= $(eval _json_indent := $$(_json_indent)$$(4space))
+json_decrease_indent =$= $(eval _json_indent := $$(subst _,$$(space),$$(patsubst %____,%,$$(subst $$(space),_,$$(_json_indent)))))
+
+# 1: Key name
+# 2: Value
+add_json_val =$= $(eval _json_contents := $$(_json_contents)$$(_json_indent)"$$(strip $$(1))": $$(strip $$(2))$$(comma)$$(newline))
+add_json_str =$= $(call add_json_val,$(1),"$(strip $(2))")
+add_json_list =$= $(call add_json_val,$(1),$(call json_list,$(patsubst %,%,$(2))))
+add_json_csv =$= $(call add_json_val,$(1),$(call csv_to_json_list,$(strip $(2))))
+add_json_bool =$= $(call add_json_val,$(1),$(if $(strip $(2)),true,false))
+add_json_map =$= $(eval _json_contents := $$(_json_contents)$$(_json_indent)"$$(strip $$(1))": {$$(newline))$(json_increase_indent)
+end_json_map =$= $(json_decrease_indent)$(eval _json_contents := $$(_json_contents)$$(if $$(filter %$$(comma),$$(lastword $$(_json_contents))),__SV_END)$$(_json_indent)},$$(newline))
+
+# Clears _json_contents to start a new json file
+json_start =$= $(eval _json_contents := {$$(newline))$(eval _json_indent := $$(4space))
+
+# Adds the trailing close brace to _json_contents, and removes any trailing commas if necessary
+json_end =$= $(eval _json_contents := $$(subst $$(comma)$$(newline)__SV_END,$$(newline),$$(_json_contents)__SV_END}$$(newline)))
+
+json_contents =$= $(_json_contents)