Create a new kati packaging step; move dist

Instead of looking at `dist` and DIST_DIR directly in the Kati Build
step, always write out information about every call to dist, then create
the rules in another ckati run.

So instead of having:

  dist:    <goal> -> <dist> -> <output>
                \______________↑

  nodist:  <goal> -----------> <output>

Always use another phony target in the Kati Build step:

   <goal> ---> <output>
        \----> _dist_<goal>

Then in the packaging step (which is much faster), choose between dist
and no dist:

  dist:   _dist_<goal> -> <dist> -> <output>

  nodist: _dist_<goal>

Bug: 117463001
Test: m dist
Change-Id: Ic96bb6356740300dd3113f6ed699e6a619360c40

8 files changed, 162 insertions, 39 deletions

diff --git a/Changes.md b/Changes.md
index baa5e6e7ac..4aa7ea2abe 100644
--- a/Changes.md
+++ b/Changes.md
@@ -1,5 +1,31 @@
 # Build System Changes for Android.mk Writers
 
+## `DIST_DIR`, `dist_goal`, and `dist-for-goals`  {#dist}
+
+`DIST_DIR` and `dist_goal` are no longer available when reading Android.mk
+files (or other build tasks). Always use `dist-for-goals` instead, which takes
+a PHONY goal, and a list of files to copy to `$DIST_DIR`. Whenever `dist` is
+specified, and the goal would be built (either explicitly on the command line,
+or as a dependency of something on the command line), that file will be copied
+into `$DIST_DIR`. For example,
+
+``` make
+$(call dist-for-goals,foo,bar/baz)
+```
+
+will copy `bar/baz` into `$DIST_DIR/baz` when `m foo dist` is run.
+
+#### Renames during copy
+
+Instead of specifying just a file, a destination name can be specified,
+including subdirectories:
+
+``` make
+$(call dist-for-goals,foo,bar/baz:logs/foo.log)
+```
+
+will copy `bar/baz` into `$DIST_DIR/logs/foo.log` when `m foo dist` is run.
+
 ## `.PHONY` rule enforcement  {#phony_targets}
 
 There are several new warnings/errors meant to ensure the proper use of
diff --git a/CleanSpec.mk b/CleanSpec.mk
index a9093d2243..39441e1082 100644
--- a/CleanSpec.mk
+++ b/CleanSpec.mk
@@ -512,6 +512,9 @@ $(call add-clean-step, rm -rf $(addsuffix /lib,\
 # Remove strip.sh intermediates to save space
 $(call add-clean-step, find $(OUT_DIR) \( -name "*.so.debug" -o -name "*.so.dynsyms" -o -name "*.so.funcsyms" -o -name "*.so.keep_symbols" -o -name "*.so.mini_debuginfo.xz" \) -print0 | xargs -0 rm -f)
 
+# Clean up old ninja files
+$(call add-clean-step, rm -f $(OUT_DIR)/build-*-dist*.ninja)
+
 # ************************************************
 # NEWER CLEAN STEPS MUST BE AT THE END OF THE LIST
 # ************************************************
diff --git a/core/config.mk b/core/config.mk
index 5491234e68..fae53bbd28 100644
--- a/core/config.mk
+++ b/core/config.mk
@@ -24,7 +24,13 @@ include $(BUILD_SYSTEM_COMMON)/core.mk
 
 # Mark variables that should be coming as environment variables from soong_ui
 # as readonly
-.KATI_READONLY := OUT_DIR TMPDIR BUILD_DATETIME_FILE DIST_DIR
+.KATI_READONLY := OUT_DIR TMPDIR BUILD_DATETIME_FILE
+ifdef CALLED_FROM_SETUP
+  .KATI_READONLY := CALLED_FROM_SETUP DIST_DIR
+endif
+ifdef KATI_PACKAGE_MK_DIR
+  .KATI_READONLY := KATI_PACKAGE_MK_DIR
+endif
 
 # Mark variables deprecated/obsolete
 CHANGES_URL := https://android.googlesource.com/platform/build/+/master/Changes.md
@@ -87,16 +93,21 @@ $(KATI_obsolete_var \
 # This is marked as obsolete in envsetup.mk after reading the BoardConfig.mk
 $(KATI_deprecate_export It is a global setting. See $(CHANGES_URL)#export_keyword)
 
-CHANGES_URL :=
-
 # Used to force goals to build.  Only use for conditionally defined goals.
 .PHONY: FORCE
 FORCE:
 
 ORIGINAL_MAKECMDGOALS := $(MAKECMDGOALS)
 
-dist_goal := $(strip $(filter dist,$(MAKECMDGOALS)))
-MAKECMDGOALS := $(strip $(filter-out dist,$(MAKECMDGOALS)))
+ifdef CALLED_FROM_SETUP
+  dist_goal := $(strip $(filter dist,$(MAKECMDGOALS)))
+  MAKECMDGOALS := $(strip $(filter-out dist,$(MAKECMDGOALS)))
+  .KATI_READONLY := dist_goal
+else
+  $(KATI_obsolete_var DIST_DIR dist_goal,Use dist-for-goals instead. See $(CHANGES_URL)#dist)
+endif
+
+CHANGES_URL :=
 
 UNAME := $(shell uname -sm)
 
diff --git a/core/distdir.mk b/core/distdir.mk
index c074186b8d..a2eabd2b3e 100644
--- a/core/distdir.mk
+++ b/core/distdir.mk
@@ -17,52 +17,52 @@
 # When specifying "dist", the user has asked that we copy the important
 # files from this build into DIST_DIR.
 
-ifdef dist_goal
-
-# $(1): source file
-# $(2): destination file
-# $(3): goals that should copy the file
-#
-define copy-one-dist-file
-$(3): $(2)
-$(2): $(1)
-	@echo "Dist: $$@"
-	$$(copy-file-to-new-target-with-cp)
-endef
-
-# A global variable to remember all dist'ed src:dst pairs.
-# So if a src:dst is already dist'ed by another goal,
-# we should just establish the dependency and don't really call the
-# copy-one-dist-file to avoid multiple rules for the same target.
+# list of all goals that depend on any dist files
+_all_dist_goals :=
+# pairs of goal:distfile
+_all_dist_goal_output_pairs :=
+# pairs of srcfile:distfile
 _all_dist_src_dst_pairs :=
+
 # Other parts of the system should use this function to associate
 # certain files with certain goals.  When those goals are built
 # and "dist" is specified, the marked files will be copied to DIST_DIR.
 #
-# $(1): a list of goals  (e.g. droid, sdk, pdk, ndk)
+# $(1): a list of goals  (e.g. droid, sdk, pdk, ndk). These must be PHONY
 # $(2): the dist files to add to those goals.  If the file contains ':',
 #       the text following the colon is the name that the file is copied
 #       to under the dist directory.  Subdirs are ok, and will be created
 #       at copy time if necessary.
 define dist-for-goals
+$(eval _all_dist_goals += $$(1)) \
 $(foreach file,$(2), \
-  $(eval fw := $(subst :,$(space),$(file))) \
-  $(eval src := $(word 1,$(fw))) \
-  $(eval dst := $(word 2,$(fw))) \
-  $(eval dst := $(if $(dst),$(dst),$(notdir $(src)))) \
-  $(if $(filter $(_all_dist_src_dst_pairs),$(src):$(dst)),\
-    $(eval $(call add-dependency,$(1),$(DIST_DIR)/$(dst))),\
-    $(eval $(call copy-one-dist-file,\
-      $(src),$(DIST_DIR)/$(dst),$(1)))\
-      $(eval _all_dist_src_dst_pairs += $(src):$(dst))\
-  )\
-)
+  $(eval src := $(call word-colon,1,$(file))) \
+  $(eval dst := $(call word-colon,2,$(file))) \
+  $(if $(dst),,$(eval dst := $$(notdir $$(src)))) \
+  $(eval _all_dist_src_dst_pairs += $$(src):$$(dst)) \
+  $(foreach goal,$(1), \
+    $(eval _all_dist_goal_output_pairs += $$(goal):$$(dst))))
 endef
 
-else # !dist_goal
+#------------------------------------------------------------------
+# To be used at the end of the build to collect all the uses of
+# dist-for-goals, and write them into a file for the packaging step to use.
 
-# empty definition when not building dist
-define dist-for-goals
+# $(1): The file to write
+define dist-write-file
+$(strip \
+  $(KATI_obsolete_var dist-for-goals,Cannot be used after dist-write-file) \
+  $(foreach goal,$(sort $(_all_dist_goals)), \
+    $(eval $$(goal): _dist_$$(goal))) \
+  $(shell mkdir -p $(dir $(1))) \
+  $(file >$(1).tmp, \
+    DIST_GOAL_OUTPUT_PAIRS := $(sort $(_all_dist_goal_output_pairs)) \
+    $(newline)DIST_SRC_DST_PAIRS := $(sort $(_all_dist_src_dst_pairs))) \
+  $(shell if ! cmp -s $(1).tmp $(1); then \
+            mv $(1).tmp $(1); \
+          else \
+            rm $(1).tmp; \
+          fi))
 endef
 
-endif # !dist_goal
+.KATI_READONLY := dist-for-goals dist-write-file
diff --git a/core/main.mk b/core/main.mk
index 967f52bbfd..3c4dd9ab7d 100644
--- a/core/main.mk
+++ b/core/main.mk
@@ -1490,6 +1490,8 @@ tidy_only:
 ndk: $(SOONG_OUT_DIR)/ndk.timestamp
 .PHONY: ndk
 
+$(call dist-write-file,$(KATI_PACKAGE_MK_DIR)/dist.mk)
+
 $(info [$(call inc_and_print,subdir_makefiles_inc)/$(subdir_makefiles_total)] writing build rules ...)
 
 endif # KATI
diff --git a/core/ninja_config.mk b/core/ninja_config.mk
index ca2dceecec..2d44d8fc6c 100644
--- a/core/ninja_config.mk
+++ b/core/ninja_config.mk
@@ -28,7 +28,6 @@ PARSE_TIME_MAKE_GOALS := \
 	custom_images \
 	deps-license \
 	dicttool_aosp \
-	dist \
 	dump-products \
 	eng \
 	fusion \
diff --git a/packaging/distdir.mk b/packaging/distdir.mk
new file mode 100644
index 0000000000..f1ef336317
--- /dev/null
+++ b/packaging/distdir.mk
@@ -0,0 +1,45 @@
+#
+# Copyright (C) 2018 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+# From the Android.mk pass:
+DIST_GOAL_OUTPUT_PAIRS :=
+DIST_SRC_DST_PAIRS :=
+include $(KATI_PACKAGE_MK_DIR)/dist.mk
+
+$(foreach pair,$(DIST_GOAL_OUTPUT_PAIRS), \
+  $(eval goal := $(call word-colon,1,$(pair))) \
+  $(eval output := $(call word-colon,2,$(pair))) \
+  $(eval .PHONY: _dist_$$(goal)) \
+  $(if $(call streq,$(DIST),true),\
+    $(eval _dist_$$(goal): $$(DIST_DIR)/$$(output))))
+
+define copy-one-dist-file
+$(2): $(1)
+	@echo "Dist: $$@"
+	rm -f $$@
+	cp $$< $$@
+endef
+
+ifeq ($(DIST),true)
+  $(foreach pair,$(DIST_SRC_DST_PAIRS), \
+    $(eval src := $(call word-colon,1,$(pair))) \
+    $(eval dst := $(DIST_DIR)/$(call word-colon,2,$(pair))) \
+    $(eval $(call copy-one-dist-file,$(src),$(dst))))
+endif
+
+copy-one-dist-file :=
+DIST_GOAL_OUTPUT_PAIRS :=
+DIST_SRC_DST_PAIRS :=
diff --git a/packaging/main.mk b/packaging/main.mk
new file mode 100644
index 0000000000..0b746a8f8e
--- /dev/null
+++ b/packaging/main.mk
@@ -0,0 +1,37 @@
+#
+# Copyright (C) 2018 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+# Create a default rule. This is unused currently, as the real default rule is
+# still in the Kati build step.
+.PHONY: _packaging_default_rule_
+_packaging_default_rule_:
+
+ifndef KATI
+$(error Only Kati is supported.)
+endif
+
+$(info [1/3] initializing packaging system ...)
+
+.KATI_READONLY := KATI_PACKAGE_MK_DIR
+
+include build/make/common/core.mk
+include build/make/common/strings.mk
+
+$(info [2/3] including distdir.mk ...)
+
+include build/make/packaging/distdir.mk
+
+$(info [3/3] writing packaging rules ...)