Support passing arguments to ddc

[annagrin]

Apologies if I missed it, but is there a way to pass arguments to ddc in build_web_compilers, for example, --canary flag?

Related: dart-lang/webdev#1949

[natebosch]

We do not currently support passing arbitrary arguments to DDC.
Is this something that we expect end users to be able to do, or is this limited to Dart team use for testing purposes?

[annagrin]

Is this something that we expect end users to be able to do, or is this limited to Dart team use for testing purposes?

This is only for testing features under development in DDC (the testing would be done in webdev). We would like to run the tests in CI to make sure debugger is prepared for any upcoming features, as well as validate that the features are ready to ship before making them enabled by default in DDC.

I appreciate any advice on how to enable them if already possible, or what changes are needed in build to make that happen. I can contribute code if needed:)

[natebosch]

In the very short term I would override to a local copy of build_web_compilers and hardcode the argument in the list.

build/build_web_compilers/lib/src/dev_compiler_builder.dart

Line 185 in ac65c07

..arguments.addAll([

If you'd like to open a PR we could make --canary an explicitly supported flag similar to how we have one for --emit-debug-symbols. https://github.com/search?q=repo%3Adart-lang%2Fbuild+emitDebugSymbols&type=code

[annagrin]

Need a longer term, will open a PR for canary flag