[dart-misc] Embedding Dart in an executable, still possible?

[Jeff Ward]

I've been trying to embed the Dart VM in an executable for a few days and I
haven't been having much luck, and I'm wondering if this is still a
supported use case.

It would be nice if the following worked:

- Pull the dart source and build libdart
- Link in libdart, include dart_api.h and have that work.

Unfortunately that doesn't work. But, here's what I've tried and still
haven't had much success.

- Pull the dart source and build the full dart executable
- link in libdart, libdart_lib, libdart_vm,
libdart_vm_precompiled_runtime, and libdouble_conversion

With this approach, I'm able to build, but when the CreateIsolate callback
gets called for the "vm-service" isolate, I call "CreateIsolate" which
ASSERTS and exits (the assert is "runtime/vm/hash_table.h:378: error:
expected: !data_->IsNull()", where the most relevant function in the
callstack is Symbols::AddPredefinedSymbolsToIsolate)

It appears that even though the documentation says Dart_Iniitialize should
support supplying a NULL for both the vm_isolate_snapshot and that
Dart_CreateIsolate should support supplying a NULL isolate_snapshot, this
is no longer the case.

So, I added in the generated snapshot files to my project source
(dart_sdk_src\sdk\build\DebugX64\obj\global_intermediate\snapshot_gen.cc)
and re-ran. This gets past CreateIsolate, but fails attempting to load the
core library. ("Dart_LookupLibrary: library 'dart:builtin' not found.").

I've tried various combinations of compiling in generated files and
compiled libs but can't find a combination that links cleanly and supplies
a version of dart:builtin.

Obviously there's some amount of secret sauce here I'm missing, but I can't
figure out the magic combination to make it work.

--
Jeff

['Florian Schneider' via Dart Misc]

Post by Jeff Ward
I've been trying to embed the Dart VM in an executable for a few days and
I haven't been having much luck, and I'm wondering if this is still a
supported use case.
- Pull the dart source and build libdart
- Link in libdart, include dart_api.h and have that work.
Unfortunately that doesn't work. But, here's what I've tried and still
haven't had much success.
- Pull the dart source and build the full dart executable
- link in libdart, libdart_lib, libdart_vm,
libdart_vm_precompiled_runtime, and libdouble_conversion

Normally you should only need libdart_vm, and not
libdart_vm_precompiled_runtime.

Post by Jeff Ward
With this approach, I'm able to build, but when the CreateIsolate callback
gets called for the "vm-service" isolate, I call "CreateIsolate" which
expected: !data_->IsNull()", where the most relevant function in the
callstack is Symbols::AddPredefinedSymbolsToIsolate)
It appears that even though the documentation says Dart_Iniitialize should
support supplying a NULL for both the vm_isolate_snapshot and that
Dart_CreateIsolate should support supplying a NULL isolate_snapshot, this
is no longer the case.
So, I added in the generated snapshot files to my project source
(dart_sdk_src\sdk\build\DebugX64\obj\global_intermediate\snapshot_gen.cc)
and re-ran. This gets past CreateIsolate, but fails attempting to load the
core library. ("Dart_LookupLibrary: library 'dart:builtin' not found.").
I've tried various combinations of compiling in generated files and
compiled libs but can't find a combination that links cleanly and supplies
a version of dart:builtin.

Hard to say what exactly is going wrong. Take a close look at
runtime/bin/main.cc as an example of how to embed libdart_vm.

Post by Jeff Ward
Obviously there's some amount of secret sauce here I'm missing, but I
can't figure out the magic combination to make it work.
--
Jeff
--
For other discussions, see https://groups.google.com/a/dartlang.org/
For HOWTO questions, visit http://stackoverflow.com/tags/dart
To file a bug report or feature request, go to http://www.dartbug.com/new
---
You received this message because you are subscribed to the Google Groups
"Dart Misc" group.
To unsubscribe from this group and stop receiving emails from it, send an

[Jeff Ward]

Hey Florian, thanks for the response!

What's in libdart_vm_precompiled_runtime?

Also, is my conclusion about Dart_CreateIsolate no longer supporting NULL
vm / isolate snapshots correct?

I did actually made some progress on this last night (by consulting
main.cc, I'll outline the fixes at the end for future generations) but
still having some issues.

Once I have a hello_world.dart file loaded, I attempt to invoke main using
Dart_Invoke, and I'm getting an error message along the lines of
"Dart_Invoke expects the library in 'target' to be loaded". I'm not sure
what to call to load the "library" other than call Dart_LoadScript (or
Dart_LoadLibrary, both do the same thing). I've added a Dart_RunLoop (which
main.cc does) but that doesn't seem to fix the issue.

Any thoughts?

How I Fixed My Dumb Issues:
First, I made sure that I'm not doing any extra work fro the vm-service
isolate that gets created when you call Dart_Initialize. In the creation
callbacks I checked for Dart_IsServiceIssolate and break out if that's the
case.
Second, the dart:builtin module is now called dart:_builtin. Loading that
library worked.

On Tue, Apr 19, 2016 at 6:32 AM, 'Florian Schneider' via Dart Misc <

Post by 'Florian Schneider' via Dart Misc

Post by Jeff Ward
I've been trying to embed the Dart VM in an executable for a few days and
I haven't been having much luck, and I'm wondering if this is still a
supported use case.
- Pull the dart source and build libdart
- Link in libdart, include dart_api.h and have that work.
Unfortunately that doesn't work. But, here's what I've tried and still
haven't had much success.
- Pull the dart source and build the full dart executable
- link in libdart, libdart_lib, libdart_vm,
libdart_vm_precompiled_runtime, and libdouble_conversion

Normally you should only need libdart_vm, and not
libdart_vm_precompiled_runtime.

Post by Jeff Ward
With this approach, I'm able to build, but when the CreateIsolate
callback gets called for the "vm-service" isolate, I call "CreateIsolate"
expected: !data_->IsNull()", where the most relevant function in the
callstack is Symbols::AddPredefinedSymbolsToIsolate)
It appears that even though the documentation says Dart_Iniitialize
should support supplying a NULL for both the vm_isolate_snapshot and that
Dart_CreateIsolate should support supplying a NULL isolate_snapshot, this
is no longer the case.
So, I added in the generated snapshot files to my project source
(dart_sdk_src\sdk\build\DebugX64\obj\global_intermediate\snapshot_gen.cc)
and re-ran. This gets past CreateIsolate, but fails attempting to load the
core library. ("Dart_LookupLibrary: library 'dart:builtin' not found.").
I've tried various combinations of compiling in generated files and
compiled libs but can't find a combination that links cleanly and supplies
a version of dart:builtin.

Hard to say what exactly is going wrong. Take a close look at
runtime/bin/main.cc as an example of how to embed libdart_vm.

Post by Jeff Ward
Obviously there's some amount of secret sauce here I'm missing, but I
can't figure out the magic combination to make it work.
--
Jeff
--
For other discussions, see https://groups.google.com/a/dartlang.org/
For HOWTO questions, visit http://stackoverflow.com/tags/dart
To file a bug report or feature request, go to http://www.dartbug.com/new
---
You received this message because you are subscribed to the Google Groups
"Dart Misc" group.
To unsubscribe from this group and stop receiving emails from it, send an

--
For other discussions, see https://groups.google.com/a/dartlang.org/
For HOWTO questions, visit http://stackoverflow.com/tags/dart
To file a bug report or feature request, go to http://www.dartbug.com/new
---
You received this message because you are subscribed to a topic in the
Google Groups "Dart Misc" group.
To unsubscribe from this topic, visit
https://groups.google.com/a/dartlang.org/d/topic/misc/BvUbN7qRhX4/unsubscribe
.
To unsubscribe from this group and all its topics, send an email to

['Florian Schneider' via Dart Misc]

Post by Jeff Ward
Hey Florian, thanks for the response!
What's in libdart_vm_precompiled_runtime?

libdart_vm_precompiled_runtime is used to run programs from a precompiled
instruction snapshot - basically a Dart app compiled into a .so file.

Post by Jeff Ward
Also, is my conclusion about Dart_CreateIsolate no longer supporting NULL
vm / isolate snapshots correct?

Passing NULL is supported. For example, see runtime/bin/gen_snapshot.cc -
it loads all sources from source files instead of a snapshot. Maybe
gen_snapshot is actually a better (simpler) example to start from than
main.cc -- but instead of creating and writing a snapshot you would invoke
main there.

Post by Jeff Ward
I did actually made some progress on this last night (by consulting
main.cc, I'll outline the fixes at the end for future generations) but
still having some issues.
Once I have a hello_world.dart file loaded, I attempt to invoke main using
Dart_Invoke, and I'm getting an error message along the lines of
"Dart_Invoke expects the library in 'target' to be loaded". I'm not sure
what to call to load the "library" other than call Dart_LoadScript (or
Dart_LoadLibrary, both do the same thing). I've added a Dart_RunLoop (which
main.cc does) but that doesn't seem to fix the issue.
Any thoughts?
First, I made sure that I'm not doing any extra work fro the vm-service
isolate that gets created when you call Dart_Initialize. In the creation
callbacks I checked for Dart_IsServiceIssolate and break out if that's the
case.
Second, the dart:builtin module is now called dart:_builtin. Loading that
library worked.
On Tue, Apr 19, 2016 at 6:32 AM, 'Florian Schneider' via Dart Misc <

Post by 'Florian Schneider' via Dart Misc

Post by Jeff Ward
I've been trying to embed the Dart VM in an executable for a few days
and I haven't been having much luck, and I'm wondering if this is still a
supported use case.
- Pull the dart source and build libdart
- Link in libdart, include dart_api.h and have that work.
Unfortunately that doesn't work. But, here's what I've tried and still
haven't had much success.
- Pull the dart source and build the full dart executable
- link in libdart, libdart_lib, libdart_vm,
libdart_vm_precompiled_runtime, and libdouble_conversion

Normally you should only need libdart_vm, and not
libdart_vm_precompiled_runtime.

Post by Jeff Ward
With this approach, I'm able to build, but when the CreateIsolate
callback gets called for the "vm-service" isolate, I call "CreateIsolate"
expected: !data_->IsNull()", where the most relevant function in the
callstack is Symbols::AddPredefinedSymbolsToIsolate)
It appears that even though the documentation says Dart_Iniitialize
should support supplying a NULL for both the vm_isolate_snapshot and that
Dart_CreateIsolate should support supplying a NULL isolate_snapshot, this
is no longer the case.
So, I added in the generated snapshot files to my project source
(dart_sdk_src\sdk\build\DebugX64\obj\global_intermediate\snapshot_gen.cc)
and re-ran. This gets past CreateIsolate, but fails attempting to load the
core library. ("Dart_LookupLibrary: library 'dart:builtin' not found.").
I've tried various combinations of compiling in generated files and
compiled libs but can't find a combination that links cleanly and supplies
a version of dart:builtin.

Hard to say what exactly is going wrong. Take a close look at
runtime/bin/main.cc as an example of how to embed libdart_vm.

Post by Jeff Ward
Obviously there's some amount of secret sauce here I'm missing, but I
can't figure out the magic combination to make it work.
--
Jeff
--
For other discussions, see https://groups.google.com/a/dartlang.org/
For HOWTO questions, visit http://stackoverflow.com/tags/dart
To file a bug report or feature request, go to
http://www.dartbug.com/new
---
You received this message because you are subscribed to the Google
Groups "Dart Misc" group.
To unsubscribe from this group and stop receiving emails from it, send

--
For other discussions, see https://groups.google.com/a/dartlang.org/
For HOWTO questions, visit http://stackoverflow.com/tags/dart
To file a bug report or feature request, go to http://www.dartbug.com/new
---
You received this message because you are subscribed to a topic in the
Google Groups "Dart Misc" group.
To unsubscribe from this topic, visit
https://groups.google.com/a/dartlang.org/d/topic/misc/BvUbN7qRhX4/unsubscribe
.
To unsubscribe from this group and all its topics, send an email to

--
For other discussions, see https://groups.google.com/a/dartlang.org/
For HOWTO questions, visit http://stackoverflow.com/tags/dart
To file a bug report or feature request, go to http://www.dartbug.com/new
---
You received this message because you are subscribed to the Google Groups
"Dart Misc" group.
To unsubscribe from this group and stop receiving emails from it, send an