This tool shows the differences between two Android-target.mk makefile. In the description below the first file is called 'reference makefile`, and the second one is called ‘our makefile’. We assume that the reference makefile was generated by the pure Soong build, and that our makefile was generated by the mixed build for the same configuration (i.e., the same target value, and our goal is thus to find out the difference that mixed build introduces.
At the moment the comparator inspects only the module sections of a file. A module section looks something like this:
include $(CLEAR_VARS) # <module type> LOCAL_MODULE := mymod LOCAL_MODULE_CLASS := ETC include $(BUILD_PREBUILT)
i.e., it always starts with include $(CLEAR_VARS) (‘module header’) line and spans until the blank line. Before a blank line there is an include <mkfile> line (‘module footer’), which may be followed by a few extra variable assignments. Between those two include lines are the assignment lines.
The name of the module is synthesized from the value of the LOCAL_MODULE variable and target configuration, e.g, apex_tzdata.com.android.tzdata|cls:ETC|target_arch:arm64 or aac_dec_fuzzer|cls:EXECUTABLES|host_arch:x86_64
The module header includes the module type as a comment (the plan was to use the mkfile on the footer line, but it proved to be common to most of the modules, so Soong was modified to provide a module detailed module type as a comment on the header line).
A module section in the reference file is compared with the identically named module section of our file. The following items are compared:
The default outputs look as follows:
159 missing modules, by type:
apex.apexBundle.files (159 modules)
Missing variables (14):
...
LOCAL_REQUIRED_MODULES, by type:
art_cc_library (2 modules)
art_cc_library_static (4 modules)
cc_library (28 modules)
cc_library_shared (2 modules)
LOCAL_SHARED_LIBRARIES, by type:
art_cc_library (60 modules)
....
Extra variables (7):
LOCAL_EXPORT_CFLAGS, by type:
cc_library (4 modules)
LOCAL_EXPORT_C_INCLUDE_DEPS, by type:
art_cc_library (28 modules)
...
Diff variables: (18)
LOCAL_EXPORT_C_INCLUDE_DEPS, by type:
aidl_interface.go_android/soong/aidl.wrapLibraryFactory.func1__topDownMutatorModule (1721 modules)
art_cc_library (12 modules)
LOCAL_PREBUILT_MODULE_FILE, by type:
apex.apexBundle (7 modules)
apex.apexBundle.files (625 modules)
...
It looks like this:
{ "RefPath": "<...>/out/soong/Android-aosp_arm64.mk", "OurPath": "<...>/out.mixed/soong/Android-aosp_arm64.mk", "MissingModules": [ "adbd.com.android.adbd|cls:EXECUTABLES|target_arch:arm64", "android.hardware.common-V2-ndk.com.android.media.swcodec|cls:SHARED_LIBRARIES|target_arch:arm64", "android.hardware.graphics.allocator-V1-ndk.com.android.media.swcodec|cls:SHARED_LIBRARIES|target_arch:arm64", "android.hardware.graphics.allocator@2.0.com.android.media.swcodec|cls:SHARED_LIBRARIES|target_arch:arm64", ... ], "DiffModules": [ { "Name": "_makenames|cls:EXECUTABLES|target_arch:arm64", "RefLocation": 137674, "OurLocation": 137673, "MissingVars": [ "LOCAL_SHARED_LIBRARIES", "LOCAL_STATIC_LIBRARIES" ], "DiffVars": [ { "Name": "LOCAL_PREBUILT_MODULE_FILE", "MissingItems": [ "out/soong/.intermediates/external/libcap/_makenames/android_arm64_armv8-a/_makenames" ], "ExtraItems": [ "out/bazel-bin/external/libcap/_makenames" ] }, { "Name": "LOCAL_SOONG_UNSTRIPPED_BINARY", "MissingItems": [ "out/soong/.intermediates/external/libcap/_makenames/android_arm64_armv8-a/unstripped/_makenames" ], "ExtraItems": [ "out/bazel-bin/external/libcap/_makenames_unstripped" ] } ] }, ... ] }
Use JSON query tool like jq to slice and dice it.
The comparator optionally:
-json). This option turns off all out output.-m N)--ignore_variables=VAR,...)--show_module_diffs)--show_type_modules)