`Dart_DebugName` and `Dart_DetectNullSafety` symbols in my executable

[ClementBeal]

Info

• Dart 3.5.3 (stable) (Wed Sep 11 16:22:47 2024 +0000) on "linux_x64"
• on linux / Linux 6.1.0-27-amd64 Process tests sometimes cause timeout on Linux #1 SMP PREEMPT_DYNAMIC Debian 6.1.115-1 (2024-11-01)
• locale is en_US.UTF-8

Problem

Hi!

Yesterday, I was trying for the first time to benchmark my code by reading the final assembly code.

That's the program I have (coming from a Twitter post) :

import 'dart:typed_data';

void main(List<String> args) {
  final u = int.parse(args[0]); 
  final r = 8372;

  final List<int> a = Uint32List(10000);

  for (int i = 0; i < 10000; i++) {
    for (int j = 0; j < 100000; j++) {
      a[i] = a[i] + j % u;
    }
    a[i] += r;
  }
  print(a[r]);
}

I compiled that code with dart compile exe my_program.dart then run objdump -d my_program.dart > output.asm to get the assembly code.

I can see a lot of Dart_DebugName and Dart_DetectNullSafety. I thought it would be compile without the debug info so I checked the available flag and with the flag -save-debugging-info, I should remove them and save them in an external file.

I run the new command dart compile exe --save-debugging-info debug.txt my_program.dart. I don't know which extension should be the debugging info file. I can already see my file getting smaller! From 5.4MB to 5.2MB!

I checked again the assembly and I still find the previous symbols Dart_DebugName and Dart_DetectNullSafety that I thought would be stripped from the final executable.

Is it a normal behavior?

[dart-github-bot]

Summary: User observes Dart_DebugName and Dart_DetectNullSafety symbols in their compiled Dart executable even after attempting to remove debug info using --save-debugging-info. They expect these symbols to be absent from the release build.

[mraleph]

These symbols are part of the Dart runtime API, has nothing to do with debug info of Dart snapshots.