XML syntax warnings when using JavaSourceJar

[cncb-gh]

Error Message or Issue

After upgrading to VS 16.10 (from 16.4), I get several general XML syntax errors when trying to compile the https://github.com/Baseflow/ExoPlayerXamarin binding library:

Severity Code Description Project File Line Suppression State Error (1 24): Syntax error, expected: #PCDATA, <tt>, <TT>, <i>, <I>, {@code, {@docRoot}, {@inheritDoc}, {@link, {@linkplain, {@literal, {@value}, {@value, UnknownHtmlElementStart, <p>, <P>, <pre>, <PRE>, @author, @apiSince, @deprecated, @deprecatedSince, @exception, @param, @return, @see, @serialData, @serialField, @since, @throws, @[unknown], @version ExoPlayer.Common C:\Craigs Files\Apps\ExoPlayerXamarin-develop\ExoPlayer.Common\BINDINGSGENERATOR 1

Version Information

Other Helpful Info

[jpobst]

I think the only current workaround for this is to remove the <JavaSourceJar> files from your .csproj files.

<JavaSourceJar Include="JavaDocs\*.jar" />

[jonpryor]

@cncb-gh: How are you observing this error? It looks like you have $(TreatWarningsAsErrors) disabled:

https://github.com/Baseflow/ExoPlayerXamarin/blob/5214b7158fc6611f602ffc0f0122429a3ae49b6d/Directory.Build.props#L22

We should only be emitting a warning for this, and probably not even a warning… (We should fix that.)

[cncb-gh]

I don' t know - they are showing up as errors in the Build Output as well as the Error List. Is there another setting in VS that might affect this?

I tried removing the source jar files and now get invalid token errors in some generated files. It is placing '?' in some methods like so (notice "void?"):

[Register ("writeToParcel", "(Landroid/os/Parcel;I)V", "GetWriteToParcel_Landroid_os_Parcel_IHandler")] public abstract void? WriteToParcel (global::Android.OS.Parcel? dest, [global::Android.Runtime.GeneratedEnum] global::Android.OS.ParcelableWriteFlags flags);

[jpobst]

Looks like this is the full output message that is being emitted:

## Unable to translate remarks for com/google/android/exoplayer2/Player:

A media player interface defining traditional high-level functionality, such as the ability to

play, pause, seek and query properties of the currently playing media.

<p>

Some important properties of media players that implement this interface are:

<ul>

    <li>They can provide a {@link Timeline} representing the structure of the media being played,

    which can be obtained by calling {@link #getCurrentTimeline()}.</li>

    <li>They can provide a {@link TrackGroupArray} defining the currently available tracks,

    which can be obtained by calling {@link #getCurrentTrackGroups()}.</li>

    <li>They contain a number of renderers, each of which is able to render tracks of a single

    type (e.g. audio, video or text). The number of renderers and their respective track types

    can be obtained by calling {@link #getRendererCount()} and {@link #getRendererType(int)}.

    </li>

    <li>They can provide a {@link TrackSelectionArray} defining which of the currently available

    tracks are selected to be rendered by each renderer. This can be obtained by calling

    {@link #getCurrentTrackSelections()}}.</li>

</ul>

Error (31:41): Syntax error, expected: #PCDATA, <tt>, <TT>, <i>, <I>, {@code, {@docRoot}, {@inheritDoc}, {@link, {@linkplain, {@literal, {@value}, {@value, UnknownHtmlElementStart, </tt>, </TT>, </i>, </I>, </p>, </P>, <p>, <P>, <pre>, <PRE>, @author, @apiSince, @deprecated, @deprecatedSince, @exception, @param, @return, @see, @serialData, @serialField, @since, @throws, @[unknown], @version
    {@link #getCurrentTrackSelections()}}.</li>
                                        ^

This part:

Error (31:41): Syntax error, expected: ......

Is close enough to the MSBuild error format that MSBuild seems to be recognizing it as an actual error, which is not intended.

I think if we change this line to something else we can get this back to an informational message as intended:

// JavadocInfo.cs: 189
writer.WriteLine ($"{m.Level} {m.Location}: {m.Message}");

[jpobst]

I have a PR that fixes MSBuild interpreting these error messages as real errors:
#851

I believe @pjcollins will be looking at improving the Javadoc parsing in the future to prevent the messages from happening in the first place.

(See also #843)

[cncb-gh]

Thanks. In the meantime, do you know how I can fix the "invalid token" error when removing the JavaDoc references?

[jpobst]

Did you remove them from all of your projects? I had tried removing them from all the projects, and did not get the invalid token errors you mentioned.