How to disassemble aot snapshots

[nielsenko]

Is it possible to decompile AOT compiled dart code?

I know how to do it for JIT snapshots, with the secret dart --disassemble flag, but I would like to do it for an AOT snapshot as well.

I see some reference to a dart_precompiled_runtime that apparently supports a --disassemble flag (ie. #41705), but this dart_precompiled_runtime is a mystery to me, and perhaps others outside google.

Could you elaborate on how to do this?

[mraleph]

There are few options.

If you are fine with using flutter tooling (rather than dart compile exe) you can just use

$ flutter build apk --extra-gen-snapshot-options=--disassemble,--code-comments,--print-flow-graph,--print-flow-graph-filter=xyz

To see code (and IL) for functions containing xyz in their names. This is not that different from JIT.

If you want to use dart compile exe then you could do:

$ dart compile aot-snapshot /tmp/test.dart
$ llvm-objdump --disassemble /tmp/test.aot

You can also use https://godbolt.org/ which has support for Dart.

[osa1]

With the commit referenced above you can also do

dart compile exe \
    --extra-gen-snapshot-options=--disassemble,--print-flow-graph,--print-flow-graph-filter=<function name> \
    -v <Dart file>