Fail if a module has missing dependencies.

    include $(CLEAR_VARS)
    LOCAL_MODULE := foo
    LOCAL_SRC_FILES := foo.cpp
    LOCAL_STATIC_LIBRARIES := never-defined
    include $(BUILD_SHARED_LIBRARY)

In the above example, the build would succeed even though it had
missing dependencies. This seems to have always been the behavior (I
checked back to r10e), so there's a good chance that there are builds
out there that depend on this behavior.

By default we will now abort in this situation because this is so
completely broken. A user may define `APP_ALLOW_MISSING_DEPS` to
"false" in their Application.mk or on the command line to revert to
the old, broken behavior.

Test: ./run_tests.py --filter APP_ALLOW_MISSING_DEPS
Bug: android/ndk#208
Change-Id: Ie77ad18a7e8000ef468c79f8e89aa2e5ae1788dd

CHANGELOG.md

@@ -16,6 +16,13 @@ Announcements
   become stable enough to be the default, as some parts of gnustl are still
   incompatible with Clang. It will likely be removed after that point.
 
+ndk-build
+---------
+
+ * Module builds will now fail if they have any missing dependencies. To revert
+   to the old behavior, set `APP_ALLOW_MISSING_DEPS=false`. See
+   https://github.com/android-ndk/ndk/issues/208.
+
 Known Issues
 ------------
 

build/core/build-binary.mk

@@ -642,6 +642,26 @@ shared_libs := $(call module-filter-shared-libraries,$(all_libs))
 static_libs := $(call module-filter-static-libraries,$(all_libs))
 whole_static_libs := $(call module-extract-whole-static-libs,$(LOCAL_MODULE),$(static_libs))
 static_libs := $(filter-out $(whole_static_libs),$(static_libs))
+all_defined_libs := $(shared_libs) $(static_libs) $(whole_static_libs)
+undefined_libs := $(filter-out $(all_defined_libs),$(all_libs))
+
+ifdef undefined_libs
+    $(call __ndk_warning,Module $(LOCAL_MODULE) depends on undefined modules: $(undefined_libs))
+
+    # https://github.com/android-ndk/ndk/issues/208
+    # ndk-build didn't used to fail the build for a missing dependency. This
+    # seems to have always been the behavior, so there's a good chance that
+    # there are builds out there that depend on this behavior (as of right now,
+    # anything using libc++ on ARM has this problem because of libunwind).
+    #
+    # By default we will abort in this situation because this is so completely
+    # broken. A user may define APP_ALLOW_MISSING_DEPS to "false" in their
+    # Application.mk or on the command line to revert to the old, broken
+    # behavior.
+    ifneq ($(APP_ALLOW_MISSING_DEPS),true)
+        $(call __ndk_error,Aborting (set APP_ALLOW_MISSING_DEPS=true to allow missing dependencies))
+    endif
+endif
 
 $(call -ndk-mod-debug,module $(LOCAL_MODULE) [$(LOCAL_BUILT_MODULE)])
 $(call -ndk-mod-debug,.  all_libs='$(all_libs)')

tests/build/APP_ALLOW_MISSING_DEPS/jni/Android.mk

@@ -0,0 +1,7 @@
+LOCAL_PATH := $(call my-dir)
+
+include $(CLEAR_VARS)
+LOCAL_MODULE := foo
+LOCAL_SRC_FILES := foo.cpp
+LOCAL_STATIC_LIBRARIES := missing-dep
+include $(BUILD_EXECUTABLE)

tests/build/APP_ALLOW_MISSING_DEPS/jni/Application.mk

@@ -0,0 +1 @@
+APP_ALLOW_MISSING_DEPS := true

tests/build/APP_ALLOW_MISSING_DEPS/jni/foo.cpp

@@ -0,0 +1,3 @@
+int main(int, char**) {
+  return 0;
+}