android: add gdb.sh

This script setup a dummy android native app folder and call ndk-gdb from it.

It needs a modification in ANDROID_NDK since ndk-gdb may attach to the wrong
pid, cf. comments in the script.

android/gdb.sh

@@ -0,0 +1,54 @@
+#!/bin/sh
+
+# This script need the following modification in ANDROID_NDK in order to attach
+# to the good :main pid
+#--- a/prebuilt/linux-x86_64/bin/ndk-gdb.py
+#+++ b/prebuilt/linux-x86_64/bin/ndk-gdb.py
+#@@ -669,7 +669,7 @@
+#             log("Sleeping for {} seconds.".format(args.delay))
+#             time.sleep(args.delay)
+#
+#-    pids = gdbrunner.get_pids(device, pkg_name)
+#+    pids = gdbrunner.get_pids(device, pkg_name + ":main")
+#     if len(pids) == 0:
+#         error("Failed to find running process '{}'".format(pkg_name))
+#     if len(pids) > 1:
+
+SCRIPT_PATH=$(dirname $0)
+BUILD_PATH="`pwd`"
+TMP_PATH="$BUILD_PATH/gdb"
+NDK_GDB_ARGS="--force"
+ANDROID_NDK=$1
+
+if [ ! -f $ANDROID_NDK/source.properties ];then
+    echo "usage: $0 ANDROID_NDK"
+    exit 1
+fi
+
+if [ ! -f $BUILD_PATH/libmpd.so ];then
+    echo "This script need to be executed from the android build directory"
+    exit 1
+fi
+
+rm -rf "$TMP_PATH"
+mkdir -p "$TMP_PATH"
+
+ANDROID_MANIFEST="$SCRIPT_PATH/AndroidManifest.xml"
+ABI=`ls "$BUILD_PATH/android/apk/apk/lib" --sort=time | head -n 1`
+
+if [ ! -f "$ANDROID_MANIFEST" -o "$ABI" = "" ]; then
+    echo "Invalid manifest/ABI, did you try building first ?"
+    exit 1
+fi
+
+mkdir -p "$TMP_PATH"/jni
+touch "$TMP_PATH"/jni/Android.mk
+echo "APP_ABI := $ABI" > "$TMP_PATH"/jni/Application.mk
+
+DEST=obj/local/$ABI
+mkdir -p "$TMP_PATH/$DEST"
+
+cp "$BUILD_PATH/libmpd.so" "$TMP_PATH/$DEST"
+cp "$ANDROID_MANIFEST" "$TMP_PATH"
+
+(cd "$TMP_PATH" && bash $ANDROID_NDK/ndk-gdb $NDK_GDB_ARGS)