Cleanup installed binaries before the NDK build begins.

Ensures that no stale/obsolete shared libraries are left in the
application's project path before the build.

Also fix a minor typo that made the ABI selection process not
work properly in certain cases.

ndk/build/core/install-binary.mk

@@ -22,7 +22,7 @@ $(LOCAL_INSTALLED_MODULE): PRIVATE_SRC  := $(LOCAL_BUILT_MODULE)
 $(LOCAL_INSTALLED_MODULE): PRIVATE_DEST := $(NDK_APP_DEST)
 $(LOCAL_INSTALLED_MODULE): PRIVATE_DST  := $(LOCAL_INSTALLED_MODULE)
 
-$(LOCAL_INSTALLED_MODULE): $(LOCAL_BUILT_MODULE)
+$(LOCAL_INSTALLED_MODULE): $(LOCAL_BUILT_MODULE) clean-installed-binaries
 	@ echo "Install        : $(PRIVATE_NAME) => $(PRIVATE_DEST)"
 	$(hide) mkdir -p $(PRIVATE_DEST)
 	$(hide) install -p $(PRIVATE_SRC) $(PRIVATE_DST)

ndk/build/core/main.mk

@@ -224,7 +224,8 @@ $(call __ndk_info,Building for application '$(NDK_APPS)')
         executables libraries static_libraries shared_libraries \
         clean clean-config clean-objs-dir \
         clean-executables clean-libraries \
-        clean-installed-modules
+        clean-installed-modules \
+        clean-installed-binaries
 
 # These macros are used in Android.mk to include the corresponding
 # build script that will parse the LOCAL_XXX variable definitions.

ndk/build/core/setup-app.mk

@@ -57,7 +57,7 @@ HOST_OBJS   := $(HOST_OUT)/objs
 # the target to use
 TARGET_TOOLCHAIN := $(NDK_TARGET_TOOLCHAIN)
 
-APP_ABI := $(strip $(APP_ABI))
+APP_ABI := $(strip $(NDK_APP_ABI))
 ifndef APP_ABI
     # the default ABI for now is armeabi
     APP_ABI := armeabi
@@ -66,12 +66,22 @@ endif
 # check the target ABIs for this application
 _bad_abis = $(strip $(filter-out $(NDK_ALL_ABIS),$(APP_ABI)))
 ifneq ($(_bad_abis),)
-    $(info _bad_abis = '$(_bad_abis)')
     $(call __ndk_info,NDK Application '$(_app)' targets unknown ABI(s): $(_bad_abis))
     $(call __ndk_info,Please fix the APP_ABI definition in $(NDK_APP_APPLICATION_MK))
     $(call __ndk_error,Aborting)
 endif
 
+# Clear all installed binaries for this application
+# This ensures that if the build fails, you're not going to mistakenly
+# package an obsolete version of it. Or if you change the ABIs you're targetting,
+# you're not going to leave a stale shared library for the old one.
+#
+ifeq ($($(_map).cleaned_binaries),)
+    $(_map).cleaned_binaries := true
+    clean-installed-binaries:
+	$(hide) rm -f $(NDK_ALL_ABIS:%=$(NDK_APP_PROJECT_PATH)/libs/%/lib*.so)
+endif
+
 $(foreach _abi,$(APP_ABI),\
     $(eval TARGET_ARCH_ABI := $(_abi))\
     $(eval include $(BUILD_SYSTEM)/setup-abi.mk) \

ndk/docs/CHANGES.TXT

@@ -56,6 +56,15 @@ IMPORTANT CHANGES:
   OpenGL ES 2.0 is currently *not* available from Java, and must be used
   through native code exclusively.
 
+- The NDK build script will now remove installed binaries from the application
+  project's path before starting the build. This ensures that:
+
+  - if the build fails for some reason, a stale/obsolete file is not left in
+    your application project tree by mistake.
+
+  - if you change the target ABI, a stale/obsolete file is not left into the
+    folder corresponding to the old ABI.
+
 
 OTHER FIXES & CHANGES: