explore using "aapt2 dump xmlstrings" or "aapt2 dump xmltree" for additional AndroidManifest.xml validation

[silbinarywolf]

tldr:

• Check if AndroidManifest.xml has android:hasCode="false", if not, then throw error saying you're missing Java files

Description

After merging #33 there is no longer any compile-time validation that you included Java files where necessary or that you've configured your AndroidManifest.xml file correctly.

For example if you have android:hasCode="false" then it's valid to not include any Java files. However if you do not include that configuration you can get the following error message when running adb install

• Scanning Failed.: Package /data/app/base.apk code is missing

My thinking is that it would be nice to create a validation build step, based off of: src/androidbuild/builtin_options_update.zig
The idea is that we should explore calling aapt2 dump xmlstrings or aapt2 dump xmltree (or something) and check if the AndroidManifest.xml has been configured correctly.

We could also put additional AndroidManifest.xml validation rules here in the future if need be.

[lumenkeyes]

What about something like:

const ValidateContext = struct {
    pub var dump_file: ?LazyPath = null;
    pub var java_file_count: ?usize = null;
};

fn validateManifest(apk: *Apk, b: *std.Build, resources_apk: LazyPath) !void {
    const aapt2_dumptree = b.addSystemCommand(&.{
        apk.tools.build_tools.aapt2,
        "dump", 
        "xmltree",
        "--file",
        "AndroidManifest.xml"
    });
    aapt2_dumptree.addFileArg(resources_apk);
    ValidateContext.dump_file = aapt2_dumptree.captureStdOut();
    const validate_step = b.step("validate manifest", "");
    validate_step.dependOn(&aapt2_dumptree.step);

    ValidateContext.java_file_count = apk.java_files.items.len;
    validate_step.makeFn = makeValidateStep;

    b.getInstallStep().dependOn(validate_step);
}

fn makeValidateStep(self: *Step, _: Step.MakeOptions) anyerror!void {
    if(ValidateContext.java_file_count.? > 0) return;
    const manifestDump = blk: {
        const file = try std.fs.cwd().openFile(ValidateContext.dump_file.?.generated.file.getPath(), .{});
        const stat = try file.stat();
        break :blk try file.readToEndAlloc(self.owner.allocator, stat.size);
    };
    if(!std.mem.containsAtLeast(u8, manifestDump, 1, "hasCode(0x0101000c)=false")) {
        _ = try self.addError("must include at least one java source file or set 'android:hasCode=false'", .{});
    }
}

[silbinarywolf]

Sort of like that but more that the validation step would be captured in its own struct like this:

• https://github.com/silbinarywolf/zig-android-sdk/blob/main/src/androidbuild/builtin_options_update.zig#L21
• https://github.com/silbinarywolf/zig-android-sdk/blob/main/src/androidbuild/apk.zig#L348-L352
  or
• https://github.com/silbinarywolf/zig-android-sdk/blob/main/src/androidbuild/d8glob.zig#L27
• https://github.com/silbinarywolf/zig-android-sdk/blob/main/src/androidbuild/apk.zig#L503

Also a concern with the approach above for me is detecting hasCode(0x0101000c). I'm not sure how stable or consistent that 0x0101000c part would be across machines/Android versions, so ideally I'd want to ignore that with regex or similar.