commit 1a218c01036c738acb47cca637cf0cdb2b509a59
author Jens Johansen <jensj@google.com> Thu Sep 11 05:33:04 2025 -0700
committer Commit Queue <dart-scoped@luci-project-accounts.iam.gserviceaccount.com> Thu Sep 11 05:33:04 2025 -0700
tree a51c3cbfc2e319a1d70b6041be02c7217f4544e8
parent 48cc23ed130ce0b553394d26a6dccf9bacc3fc06

[kernel/CFE] Dill extractor tool; CFE compile dir tool; fixes for stats

This CL adds two tools
* A dill extractor tool which extracts the source files inside the dill
  to a new directory, trying to recrease the package config too so the
  sources can be compiled again. Thought as being useful for doing
  benchmarks between the CFE and the analyzer to make sure they look at
  the exact same source files. No more. No less.
* A CFE compile entry point that compiles all files in a directory.
  Again thought as being useful to compare the CFE with the Analyzer.

Additionally it introduces "--gcs=<int>" to `benchmarker.dart` so it can
do multiple runs and do statistics on combined gc times.

Usage example:

```
$ out/ReleaseX64/dart pkg/front_end/tool/compile.dart pkg/front_end/tool/compile.dart

$ out/ReleaseX64/dart-sdk/bin/dart pkg/kernel/bin/dill_extractor.dart pkg/front_end/tool/compile.dart.dill /tmp/extracted_compile_dart_compile
Done. Wrote 687 source files.

$ out/ReleaseX64/dart-sdk/bin/dart compile aot-snapshot pkg/front_end/tool/compile_files_in_folders.dart
Generated: [...]/pkg/front_end/tool/compile_files_in_folders.aot

$ out/ReleaseX64/dart-sdk/bin/dart compile aot-snapshot pkg/analyzer_cli/bin/analyzer.dart
Generated: [...]/pkg/analyzer_cli/bin/analyzer.aot

$ time out/ReleaseX64/dart-sdk/bin/dartaotruntime pkg/front_end/tool/compile_files_in_folders.aot /tmp/extracted_compile_dart_compile/
Got 626 libraries.
Finished in 0:00:03.496817

real    0m3.530s
user    0m4.985s
sys     0m0.257s

$ time out/ReleaseX64/dart-sdk/bin/dartaotruntime pkg/analyzer_cli/bin/analyzer.aot /tmp/extracted_compile_dart_compile/
Analyzing /tmp/extracted_compile_dart_compile...
  warning • Target of URI doesn't exist: 'package:compiler/src/io/source_file.dart'. • package:_fe_analyzer_shared/src/scanner/utf8_bytes_scanner.dart:5:16 • uri_does_not_exist_in_doc_import
1 warning found.

real    0m8.479s
user    0m9.997s
sys     0m1.048s


$ out/ReleaseX64/dart pkg/front_end/tool/benchmarker.dart --silent --iterations=10 --gcs=5 --snapshot=pkg/front_end/tool/compile_files_in_folders.aot --snapshot=pkg/analyzer_cli/bin/analyzer.aot --arguments="/tmp/extracted_compile_dart_compile/"
Will now run 10 iterations with 2 snapshots.
..............................

Comparing snapshot #1 (compile_files_in_folders.aot) with snapshot #2 (analyzer.aot)
msec task-clock:u: 141.1012% +/- 1.5550% (6281.55 +/- 69.22) (4451.81 -> 10733.36)
page-faults:u: 47.5414% +/- 0.7786% (45602.90 +/- 746.84) (95922.50 -> 141525.40)
cycles:u: 119.3182% +/- 1.5751% (22131655652.90 +/- 292155654.08) (18548436164.50 -> 40680091817.40)
instructions:u: 140.2463% +/- 0.0340% (30410953910.60 +/- 7375789.67) (21683959961.20 -> 52094913871.80)
branch-misses:u: 97.9816% +/- 7.3049% (73071988.00 +/- 5447773.30) (74577266.40 -> 147649254.40)
seconds time elapsed: 141.0789% +/- 1.5479% (6.28 +/- 0.07) (4.45 -> 10.74)
seconds user: 124.4165% +/- 1.8322% (5.31 +/- 0.08) (4.26 -> 9.57)
seconds sys: 521.0422% +/- 17.4291% (0.98 +/- 0.03) (0.19 -> 1.16)
Comparing GC:
Combined GC time: 63.8901% +/- 1.2946% (1008.76 +/- 20.44) (1578.90 -> 2587.66)
```

(note that benchmarker passes `--deterministic` and limits the run to one cpu, both of which (potentially) makes it slower --- which is why the stats say 4.45 s instead of ~3.53 s and 10.74 s instead of ~8.48 s)

Change-Id: I785620ce40af11ca1f7b6c88a0ac863b2200f7d3
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/449180
Reviewed-by: Johnni Winther <johnniwinther@google.com>
Commit-Queue: Jens Johansen <jensj@google.com>