Add fieldnull tool
The fieldnull tool uses jvmti to allow one to examine which portion of
a fields values are null on a running process. This can be used to
determine if changing the layout or implementation of a class would be
appropriate when the data is optional.
Bug: 32635074
Test: ./test/run-test --debuggable \
--host \
--dev \
--with-agent 'libfieldnull.so=Ljava/lang/Class;.name:Ljava/lang/String;' \
001-HelloWorld
Test: am start-activity \
-S \
--attach-agent '/data/local/tmp/libfieldnull.so=Ljava/lang/Class;.name:Ljava/lang/String;' \
com.antonioleiva.bandhookkotlin/.ui.screens.main.mainactivity;
kill -3 $(pidof com.antonioleiva.bandhookkotlin)
Change-Id: If64a9720d97625761556d78e881662f84953115f
diff --git a/tools/field-null-percent/Android.bp b/tools/field-null-percent/Android.bp
new file mode 100644
index 0000000..26bb1dc
--- /dev/null
+++ b/tools/field-null-percent/Android.bp
@@ -0,0 +1,56 @@
+//
+// 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.
+//
+
+// Build variants {target,host} x {debug,ndebug} x {32,64}
+cc_defaults {
+ name: "fieldnull-defaults",
+ host_supported: true,
+ srcs: ["fieldnull.cc"],
+ defaults: ["art_defaults"],
+
+ // Note that this tool needs to be built for both 32-bit and 64-bit since it requires
+ // to be same ISA as what it is attached to.
+ compile_multilib: "both",
+
+ shared_libs: [
+ "libbase",
+ ],
+ header_libs: [
+ "libopenjdkjvmti_headers",
+ ],
+ multilib: {
+ lib32: {
+ suffix: "32",
+ },
+ lib64: {
+ suffix: "64",
+ },
+ },
+ symlink_preferred_arch: true,
+}
+
+art_cc_library {
+ name: "libfieldnull",
+ defaults: ["fieldnull-defaults"],
+}
+
+art_cc_library {
+ name: "libfieldnulld",
+ defaults: [
+ "art_debug_defaults",
+ "fieldnull-defaults",
+ ],
+}