Merge "Make duplicate COPY_HEADERS an error"

# If more than one makefile declared a header, print a warning,

# If more than one makefile declared a header, print a warning,

# then copy the last one defined. This matches the previous make

# then copy the last one defined. This matches the previous make

# behavior.

# behavior.

has_dup_copy_headers :=

$(foreach dest,$(ALL_COPIED_HEADERS), \

$(foreach dest,$(ALL_COPIED_HEADERS), \

    $(eval _srcs := $(ALL_COPIED_HEADERS.$(dest).SRC)) \

    $(eval _srcs := $(ALL_COPIED_HEADERS.$(dest).SRC)) \

    $(eval _src := $(word $(words $(_srcs)),$(_srcs))) \

    $(eval _src := $(word $(words $(_srcs)),$(_srcs))) \

    $(if $(call streq,$(_src),$(_srcs)),, \

    $(if $(call streq,$(_src),$(_srcs)),, \

        $(warning Duplicate header copy: $(dest)) \

        $(warning Duplicate header copy: $(dest)) \

	$(warning Defined in: $(ALL_COPIED_HEADERS.$(dest).MAKEFILE))) \

	$(warning Defined in: $(ALL_COPIED_HEADERS.$(dest).MAKEFILE)) \

	$(eval has_dup_copy_headers := true)) \

    $(eval $(call copy-one-header,$(_src),$(dest))))

    $(eval $(call copy-one-header,$(_src),$(dest))))

all_copied_headers: $(ALL_COPIED_HEADERS)

all_copied_headers: $(ALL_COPIED_HEADERS)

ifdef has_dup_copy_headers

  has_dup_copy_headers :=

  ifneq ($(BUILD_BROKEN_DUP_COPY_HEADERS),true)

    $(error duplicate header copies are no longer allowed. For more information about headers, see: https://android.googlesource.com/platform/build/soong/+/master/docs/best_practices.md#headers)

  endif

endif

# -----------------------------------------------------------------

# -----------------------------------------------------------------

# docs/index.html

# docs/index.html

ifeq (,$(TARGET_BUILD_APPS))

ifeq (,$(TARGET_BUILD_APPS))