Add hot reload support when building with GCC and CMake

[ytnuf]

This is a small continuation to PR #1330 which adds hot reloading options for CMake

However when compiling with GCC, the option -fno-gnu-unique must also be enabled to allow hot reloading.
This is done in the SCons script:

godot-cpp/tools/linux.py

Line 20 in 9b98377

env.Append(CXXFLAGS=["-fno-gnu-unique"])

[jpxaraujo]

Even with this, it still does not work for me. Maybe i'm missing something?

[dsnopek]

Thanks!

Insofar as I understand cmake, this seems good. I only have the one note

[dsnopek]

We have the compiler_is_gnu variable defined above. Could we use?

[ytnuf]

Yep! But since it's a generator expression, it requires a slightly different approach (using the target_compile_options function instead).

[dsnopek]

@jpxaraujo:

Even with this, it still does not work for me. Maybe i'm missing something?

That error is usually caused by not having HOT_RELOAD_ENABLED defined, which I think is set via calling cmake with -DGODOT_ENABLE_HOT_RELOAD.

[jpxaraujo]

@jpxaraujo:

Even with this, it still does not work for me. Maybe i'm missing something?

That error is usually caused by not having HOT_RELOAD_ENABLED defined, which I think is set via calling cmake with -DGODOT_ENABLE_HOT_RELOAD.

@dsnopek Thanks for the reply!

So, I added the changes in this commit, added "reloadable = true" to .gdextension and added the HOT_RELOAD_ENABLED

But still have the same problem ...

[Drahiri]

Finally made it work.
@jpxaraujo for hot reloading to work you also need to include HOT_RELOAD_ENABLED and -fno-gnu-unique flag when building your shared library.
Adding this worked

set_property(TARGET ${LIBRARY_NAME} APPEND_STRING PROPERTY COMPILE_FLAGS "-D HOT_RELOAD_ENABLED -fno-gnu-unique")

Where ${LIBRARY_NAME} is name of target from add_library().

[jpxaraujo]

@Drahiri well, I am bit confused I think. It was already working when running a scene. But I thought it would also update the scene in the editor.
It would be a game changer if we could get an automatic update for scenes in the editor.

[Drahiri]

It's doing exactly that. After I updated CMake to match this pull request and updated mine CMake with that line. After rebuilding shared library, editor automatically updated without that message asking if hot reloading is enabled.
No need to reload whole project to see changes.

[jpxaraujo]

@Drahiri I followed every step, It does not work for me, don't know why. I tried in two different systems, one with a 12800h and a 3050ti with fedora and another with 5800X3D and a 6950xt with gentoo ...
It only updates if I run the scene, the editor does not change for me ...

[Drahiri]

@jpxaraujo I've added repo with working example. Also sorry to all staff if it's turning into spam (I feel like a little).

[jpxaraujo]

@jpxaraujo I've added repo with working example. Also sorry to all staff if it's turning into spam (I feel like a little).

Thank you for taking your time to create an example! Hopefully it can help other people. Will test it today or tomorrow.
Regarding the spam, my bad, I'm sorry for that.

[ytnuf]

Now using the compiler_is_gnu generator expression as suggested.

[dsnopek]

Thanks!

[dsnopek]

Cherry-picked for 4.2 in PR #1631

[dsnopek]

Cherry-picked for 4.3 in PR #1632