Do not obfuscate library uris when the library contains entrypoint annotation

[mkustermann]

If a library contains a @pragma('vm:entry-point') annotation we should ensure to not obfuscate library uris as well as ensure to keep library uris available to make it possible for an embedder to invoke such an entry point.

[stuartmorgan]

How difficult would this be to fix? We're hitting more issues with this recently in Flutter due to new plugin registration mechanics; is this something we could potentially fix in the short term instead of having to work around it?

[alexmarkov]

This bug has been causing multiple problems, so we should probably bump its priority. Tentatively assigning P1.

/cc @a-siva @mraleph

[mraleph]

@jensjoha Jens, could you take a look at this to unblock Flutter? It should be doable in the Kernel transforms that computes obfuscation prohibitions. (ObfuscationProhibitionsVisitor), so should be doable in pure Dart.

[jensjoha]

So the suggested fix works when plugged in to flutter.

But for my own curiosity I couldn't figure out where the obfuscation was happening in the VM (without the proposed fix), considering the uri isn't obfuscated in kernel_loader.cc. So for future reference it happens here:

sdk/runtime/vm/compiler/aot/precompiler.cc

Lines 2968 to 2977 in 33c38e9

	Obfuscator obfuscator(T, /*private_key=*/String::Handle(Z));
	String& str = String::Handle(Z);
	for (intptr_t i = 0; i < scripts.length(); i++) {
	const Script& script = scripts.At(i);
	str = script.url();
	str = Symbols::New(T, str);
	str = obfuscator.Rename(str, /*atomic=*/true);
	script.set_url(str);
	}

Fix in the pipeline @ https://dart-review.googlesource.com/c/sdk/+/236220.

[stuartmorgan]

Is this fixed for master, or is there more follow-up needed?

[mraleph]

I am gonna close given that @jensjoha has tested with Flutter and says it works.

[stuartmorgan]

Awesome, thanks for the quick fix!

[absar]

Any estimates when it will land into Flutter stable? It's a blocker, since it's preventing us from releasing obfuscated Apps since Flutter 2.10

[absar]

Issue still exists in Flutter Channel stable 3.0.1 when APK or appbundle is obfuscated

Background plugin isolate log:

2022-06-03 19:56:02.589 29540-1486/? E/flutter: [ERROR:flutter/shell/common/shell.cc(93)] Dart Unhandled Exception:
NoSuchMethodError: No top-level getter 'Ild' declared.
  Receiver: top-level
  Tried calling: Ild, stack trace: Warning: This VM has been configured to produce stack traces that violate the Dart standard.
  *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
  pid: 29540, tid: 1486, name Unknown
  build_id: '8deece9b97153dcde758a3ce15c56eaf'
  isolate_dso_base: 7830404000, vm_dso_base: 7830404000
  isolate_instructions: 78306bc7f0, vm_instructions: 78306b8000
      #00 abs 00000078306c5eb3 virt 00000000002c1eb3 _kDartIsolateSnapshotInstructions+0x96c3
2022-06-03 19:56:02.589 29540-1486/? E/flutter: [ERROR:flutter/runtime/dart_isolate.cc(668)] Could not resolve main entrypoint function.
2022-06-03 19:56:02.589 29540-1486/? E/flutter: [ERROR:flutter/runtime/dart_isolate.cc(167)] Could not run the run main Dart entrypoint.
2022-06-03 19:56:02.592 29540-1486/? E/flutter: [ERROR:flutter/runtime/runtime_controller.cc(382)] Could not create root isolate.
2022-06-03 19:56:02.592 29540-1486/? E/flutter: [ERROR:flutter/shell/common/shell.cc(600)] Could not launch engine with configuration.

[srmncnk]

Probably flutter_isolate plugin is affected as well.

[mraleph]

@absar please file a separate issue with instructions on how to reproduce.

[absar]

@mraleph filed #49181

[conanlovevit]

Still error with 2.10.5 when APK or appbundle is obfuscated, My phone shows black screen.
Any suggest please?