Read BUILD_NUMBER from file in rules

Using $(BUILD_NUMBER) inside a rule causes odd behavior, as the rule
is different every time make is run, but since make doesn't depend
on the command line it only ends up being built with the new value
if some other dependency has changed.

To allow ninja, which does depend on the command line, to provide the
same behavior, store the build number in out/build_number.txt, and
use a shell expansion to cat the file in rules that use it.  This will
cause the rule command to stay identical between builds, while still
getting the new build number if the rule is rerun for a dependency.

Also use the same trick for BUILD_FINGERPRINT, and the date in
droiddoc rules.

Change-Id: I6c5e6b6b3ef4c613563d7f5604df0e401575ba5f
diff --git a/core/Makefile b/core/Makefile
index d66855a..c35f744 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -106,7 +106,7 @@
 BUILD_VERSION_TAGS := $(subst $(space),$(comma),$(sort $(BUILD_VERSION_TAGS)))
 
 # A human-readable string that descibes this build in detail.
-build_desc := $(TARGET_PRODUCT)-$(TARGET_BUILD_VARIANT) $(PLATFORM_VERSION) $(BUILD_ID) $(BUILD_NUMBER) $(BUILD_VERSION_TAGS)
+build_desc := $(TARGET_PRODUCT)-$(TARGET_BUILD_VARIANT) $(PLATFORM_VERSION) $(BUILD_ID) $(BUILD_NUMBER_FROM_FILE) $(BUILD_VERSION_TAGS)
 $(INSTALLED_BUILD_PROP_TARGET): PRIVATE_BUILD_DESC := $(build_desc)
 
 # The string used to uniquely identify the combined build and product; used by the OTA server.
@@ -124,6 +124,9 @@
   $(error BUILD_FINGERPRINT cannot contain spaces: "$(BUILD_FINGERPRINT)")
 endif
 
+$(shell echo $(BUILD_FINGERPRINT) > $(PRODUCT_OUT)/build_fingerprint.txt)
+BUILD_FINGERPRINT_FROM_FILE := $$(cat $(PRODUCT_OUT)/build_fingerprint.txt)
+
 # The string used to uniquely identify the system build; used by the OTA server.
 # This purposefully excludes any product-specific variables.
 ifeq (,$(strip $(BUILD_THUMBPRINT)))
@@ -147,7 +150,7 @@
 
   # Dev. branches should have DISPLAY_BUILD_NUMBER set
   ifeq "true" "$(DISPLAY_BUILD_NUMBER)"
-    BUILD_DISPLAY_ID := $(BUILD_ID).$(BUILD_NUMBER) $(BUILD_KEYS)
+    BUILD_DISPLAY_ID := $(BUILD_ID).$(BUILD_NUMBER_FROM_FILE) $(BUILD_KEYS)
   else
     BUILD_DISPLAY_ID := $(BUILD_ID) $(BUILD_KEYS)
   endif
@@ -194,14 +197,14 @@
 			PRIVATE_BUILD_DESC="$(PRIVATE_BUILD_DESC)" \
 			BUILD_ID="$(BUILD_ID)" \
 			BUILD_DISPLAY_ID="$(BUILD_DISPLAY_ID)" \
-			BUILD_NUMBER="$(BUILD_NUMBER)" \
+			BUILD_NUMBER="$(BUILD_NUMBER_FROM_FILE)" \
 			PLATFORM_VERSION="$(PLATFORM_VERSION)" \
 			PLATFORM_SDK_VERSION="$(PLATFORM_SDK_VERSION)" \
 			PLATFORM_VERSION_CODENAME="$(PLATFORM_VERSION_CODENAME)" \
 			PLATFORM_VERSION_ALL_CODENAMES="$(PLATFORM_VERSION_ALL_CODENAMES)" \
 			BUILD_VERSION_TAGS="$(BUILD_VERSION_TAGS)" \
 			TARGET_BOOTLOADER_BOARD_NAME="$(TARGET_BOOTLOADER_BOARD_NAME)" \
-			BUILD_FINGERPRINT="$(BUILD_FINGERPRINT)" \
+			BUILD_FINGERPRINT="$(BUILD_FINGERPRINT_FROM_FILE)" \
 			$(if $(OEM_THUMBPRINT_PROPERTIES),BUILD_THUMBPRINT="$(BUILD_THUMBPRINT)") \
 			TARGET_BOARD_PLATFORM="$(TARGET_BOARD_PLATFORM)" \
 			TARGET_CPU_ABI_LIST="$(TARGET_CPU_ABI_LIST)" \
@@ -244,7 +247,7 @@
 	$(hide) echo > $@
 	$(hide) echo ro.vendor.build.date=`date`>>$@
 	$(hide) echo ro.vendor.build.date.utc=`date +%s`>>$@
-	$(hide) echo ro.vendor.build.fingerprint="$(BUILD_FINGERPRINT)">>$@
+	$(hide) echo ro.vendor.build.fingerprint="$(BUILD_FINGERPRINT_FROM_FILE)">>$@
 endif
 
 # ----------------------------------------------------------------
@@ -260,7 +263,7 @@
 	$(hide) echo > $@
 	$(hide) echo ro.bootimage.build.date=`date`>>$@
 	$(hide) echo ro.bootimage.build.date.utc=`date +%s`>>$@
-	$(hide) echo ro.bootimage.build.fingerprint="$(BUILD_FINGERPRINT)">>$@
+	$(hide) echo ro.bootimage.build.fingerprint="$(BUILD_FINGERPRINT_FROM_FILE)">>$@
 
 # -----------------------------------------------------------------
 # sdk-build.prop
diff --git a/core/definitions.mk b/core/definitions.mk
index a9d09ef..fad753f 100644
--- a/core/definitions.mk
+++ b/core/definitions.mk
@@ -1664,8 +1664,8 @@
     $(addprefix -G , $(PRIVATE_PROGUARD_OPTIONS_FILE)) \
     $(addprefix --min-sdk-version , $(PRIVATE_DEFAULT_APP_TARGET_SDK)) \
     $(addprefix --target-sdk-version , $(PRIVATE_DEFAULT_APP_TARGET_SDK)) \
-    $(if $(filter --version-code,$(PRIVATE_AAPT_FLAGS)),,$(addprefix --version-code , $(PLATFORM_SDK_VERSION))) \
-    $(if $(filter --version-name,$(PRIVATE_AAPT_FLAGS)),,$(addprefix --version-name , $(PLATFORM_VERSION)-$(BUILD_NUMBER))) \
+    $(if $(filter --version-code,$(PRIVATE_AAPT_FLAGS)),,--version-code $(PLATFORM_SDK_VERSION)) \
+    $(if $(filter --version-name,$(PRIVATE_AAPT_FLAGS)),,--version-name $(PLATFORM_VERSION)-$(BUILD_NUMBER_FROM_FILE)) \
     $(addprefix --rename-manifest-package , $(PRIVATE_MANIFEST_PACKAGE_NAME)) \
     $(addprefix --rename-instrumentation-target-package , $(PRIVATE_MANIFEST_INSTRUMENTATION_FOR))
 endef
@@ -1788,7 +1788,7 @@
         $(PRIVATE_CLASS_INTERMEDIATES_DIR)/$(subst .,/,$(pkg))))
 $(if $(PRIVATE_RMTYPEDEFS), $(hide) $(RMTYPEDEFS) -v $(PRIVATE_CLASS_INTERMEDIATES_DIR))
 $(if $(PRIVATE_JAR_MANIFEST), \
-    $(hide) sed -e 's/%BUILD_NUMBER%/$(BUILD_NUMBER)/' \
+    $(hide) sed -e "s/%BUILD_NUMBER%/$(BUILD_NUMBER_FROM_FILE)/" \
             $(PRIVATE_JAR_MANIFEST) > $(dir $@)/manifest.mf && \
         jar -cfm $@ $(dir $@)/manifest.mf \
             -C $(PRIVATE_CLASS_INTERMEDIATES_DIR) ., \
@@ -1990,7 +1990,7 @@
         $(PRIVATE_CLASS_INTERMEDIATES_DIR)/$(subst .,/,$(pkg))))
 $(if $(PRIVATE_RMTYPEDEFS), $(hide) $(RMTYPEDEFS) -v $(PRIVATE_CLASS_INTERMEDIATES_DIR))
 $(if $(PRIVATE_JAR_MANIFEST), \
-    $(hide) sed -e 's/%BUILD_NUMBER%/$(BUILD_NUMBER)/' \
+    $(hide) sed -e "s/%BUILD_NUMBER%/$(BUILD_NUMBER_FROM_FILE)/" \
             $(PRIVATE_JAR_MANIFEST) > $(dir $@)/manifest.mf && \
         jar -cfm $@ $(dir $@)/manifest.mf \
             -C $(PRIVATE_CLASS_INTERMEDIATES_DIR) ., \
@@ -2093,8 +2093,8 @@
     $(addprefix --min-sdk-version , $(PRIVATE_DEFAULT_APP_TARGET_SDK)) \
     $(addprefix --target-sdk-version , $(PRIVATE_DEFAULT_APP_TARGET_SDK)) \
     $(if $(filter --product,$(PRIVATE_AAPT_FLAGS)),,$(addprefix --product , $(TARGET_AAPT_CHARACTERISTICS))) \
-    $(if $(filter --version-code,$(PRIVATE_AAPT_FLAGS)),,$(addprefix --version-code , $(PLATFORM_SDK_VERSION))) \
-    $(if $(filter --version-name,$(PRIVATE_AAPT_FLAGS)),,$(addprefix --version-name , $(PLATFORM_VERSION)-$(BUILD_NUMBER))) \
+    $(if $(filter --version-code,$(PRIVATE_AAPT_FLAGS)),,--version-code $(PLATFORM_SDK_VERSION)) \
+    $(if $(filter --version-name,$(PRIVATE_AAPT_FLAGS)),,--version-name $(PLATFORM_VERSION)-$(BUILD_NUMBER_FROM_FILE)) \
     $(addprefix --rename-manifest-package , $(PRIVATE_MANIFEST_PACKAGE_NAME)) \
     $(addprefix --rename-instrumentation-target-package , $(PRIVATE_MANIFEST_INSTRUMENTATION_FOR)) \
     -F $@
diff --git a/core/droiddoc.mk b/core/droiddoc.mk
index 41f135c..0de1837 100644
--- a/core/droiddoc.mk
+++ b/core/droiddoc.mk
@@ -131,8 +131,8 @@
 	$(HOST_OUT_JAVA_LIBRARIES)/doclava$(COMMON_JAVA_PACKAGE_SUFFIX)
 
 $(full_target): PRIVATE_DOCLETPATH := $(HOST_OUT_JAVA_LIBRARIES)/jsilver$(COMMON_JAVA_PACKAGE_SUFFIX):$(HOST_OUT_JAVA_LIBRARIES)/doclava$(COMMON_JAVA_PACKAGE_SUFFIX)
-$(full_target): PRIVATE_CURRENT_BUILD := -hdf page.build $(BUILD_ID)-$(BUILD_NUMBER)
-$(full_target): PRIVATE_CURRENT_TIME :=  -hdf page.now "$(shell date "+%d %b %Y %k:%M")"
+$(full_target): PRIVATE_CURRENT_BUILD := -hdf page.build $(BUILD_ID)-$(BUILD_NUMBER_FROM_FILE)
+$(full_target): PRIVATE_CURRENT_TIME :=  -hdf page.now "$$(date "+%d %b %Y %k:%M")"
 $(full_target): PRIVATE_CUSTOM_TEMPLATE_DIR := $(LOCAL_DROIDDOC_CUSTOM_TEMPLATE_DIR)
 $(full_target): PRIVATE_IN_CUSTOM_ASSET_DIR := $(LOCAL_DROIDDOC_CUSTOM_TEMPLATE_DIR)/$(LOCAL_DROIDDOC_CUSTOM_ASSET_DIR)
 $(full_target): PRIVATE_OUT_ASSET_DIR := $(out_dir)/$(LOCAL_DROIDDOC_ASSET_DIR)
diff --git a/core/main.mk b/core/main.mk
index 7f561ab..7f22d76 100644
--- a/core/main.mk
+++ b/core/main.mk
@@ -93,6 +93,12 @@
 # and host information.
 include $(BUILD_SYSTEM)/config.mk
 
+# Write the build number to a file so it can be read back in
+# without changing the command line every time.  Avoids rebuilds
+# when using ninja.
+$(shell echo -n $(BUILD_NUMBER) > $(OUT_DIR)/build_number.txt)
+BUILD_NUMBER_FROM_FILE := $$(cat $(OUT_DIR)/build_number.txt)
+
 # CTS-specific config.
 -include cts/build/config.mk