I'm using unit tests with my ANTLR3-generated parser project to verify my grammar definition. I just downloaded NCrunch to trial its use as well, but it seems to have some problems with ANTLR3.

In order to get ANTLR builds working at all, I first needed to add the grammar file (.g3) and the ANTLR directory (../Reference/**.*) to "Additional files to include" for the parser project. Now, builds work sometimes: generally, it seems to work when I first start Visual Studio, and often starts to fail when I'm editing the grammar file, but doesn't usually recover from that even after I'm done editing and can run unit tests manually through Test Explorer.

The error I get from NCrunch for the build is rather opaque:


This is rather weird in that Antlr3.Targets.CSharp3Target is derived from Antlr3.Codegen.Target, so it should be possible to cast in that direction. The line 126 on Antlr3.targets is the AntlrClassGenerationTask, but I don't see anything wrong with it (plus, the project builds ok in Visual Studio and when I run it through MSBuild).

Does anyone have any ideas what could be different between the way VS2012 and NCrunch builds the software that could cause this error?

Edit: Oops, forgot to mention tools' versions. NCrunch 1.45.0.12, antlr-dotnet-tool-3.5.0.2, and Visual Studio 2012.

Hi, and thanks for the quick reply.



I forgot to mention I'd tried enabling 'Copy referenced assemblies to workspace' earlier, but switched it back off since I didn't see any difference. I now set NCrunch to compatibility mode (which appears to include this setting as well), but this doesn't seem to make a difference either - I still get the same build failure. Note: I did the project-specific steps here only for the project that has the build failure; this project doesn't depend on other projects though.



Ok, I tried this, and MSBuild invocation (c:\Windows\Microsoft.NET\Framework64\v4.0.30319\MSBuild /m {parserproject}.csproj) works ok in the NCrunch workspace. I do get two warnings regarding CLSCompliant attributes not being needed for the lexer and parser from MSBuild, but I get these in Visual Studio as well.

Ok, tried this, first without compatibility mode, and then with compatibility mode on, but neither case made a difference.



Wilco.



No, sorry, this is a closed source one, but I can try to create a solution that I can send - that shouldn't be too difficult as my project currently doesn't have much else besides the ANTLR stuff, so I expect a basic calculator project using ANTLR might fail just the same.

Thanks for sharing the sample code. It took quite a bit of digging through this sample and the Antlr3 source code to finally figure this out.

It seems that Antlr3 has been designed in the assumption that the process executed to host the build will only be used once for a single build, before being terminated. Normally this is a safe assumption, as when building your project via Visual Studio or the command line, MSBuild will launch, then execute a single build task, then terminate cleanly.

Because of the overhead involved in launching processes to host builds, NCrunch doesn't follow this pattern - it will instead re-use build processes as many times as practical to build many different projects. This normally doesn't cause problems, but in this case, it clashes with the design of Antlr3's build logic. Antlr3 appears to perform some kind of task that manipulates the state of the build process (i.e. manually loading referenced assemblies or something along these lines), which messes up the internal type resolution of the CLR (hence the error message describing one type not being castable to another when it is a clear descendant of this type). Without changing Antlr3, the only way to allow subsequent executions of the build to perform normally is by forcing a restart of the process used to execute the build.

NCrunch has a configuration option that can do just this. Try changing the build process memory limit global configuration option to '1'. In this way, NCrunch will evaluate the memory utilisation of the build process after each build, then restart it, as memory utilisation will always be higher than 1.

You'll notice that the lack of re-use of the build process has an impact on the performance of NCrunch, but unfortunately there isn't much that can be done here without changing Antlr3.

I hope this helps!


Cheers,

Remco