Added hot reload support to CMakeLists.txt

[pimms]

Add support for hot reloading when building godot-cpp using CMake.

CMake projects can enable the reloading by setting GODOT_ENABLE_HOT_RELOAD to ON before including the godot-cpp subdirectory.

Example:

set(GODOT_ENABLE_HOT_RELOAD ON)
add_subdirectory("${CMAKE_CURRENT_SOURCE_DIR}/godot-cpp/" build-godot-cpp)

I believe I've done all of this correctly — I'm super new to both Godot and Scons, but from how I understand the Scons-support for hot reloading in #1200, I believe this to be correct.

[AThousandShips]

This does not match what the code does for scons, it defaults to true if you are not on a release build:

if env.get("use_hot_reload") is None:
    env["use_hot_reload"] = env["target"] != "template_release"

This should be reflected here

[AThousandShips]

You should document this option above along with the rest

[pimms]

Thanks for the comments! I've made changes accordingly, but I was not able to set the default value in a particularly elegant manner. My CMake skills are quite basic, and I couldn't get generator expressions to work as I wanted, hence the ugly if (...)/else().

[pimms]

@AThousandShips

[AThousandShips]

Why are you pinging me with no question or anything? Please don't just ping people to boost things 🙁

[pimms]

I'm not sure how reviews and merging in Godot typically goes, but I fixed the comments 10 days ago and left a comment about it. The ping was just a friendly notification in case you didn't see it.

[AThousandShips]

Understood, but then please make that clear, just pinging someone without any details isn't very friendly 🙂

The review process can be slow at times, especially at this time of year, I mainly gave some minor details and would have approved had it been something I was ready to do, I get updates when things change so no worries, no need to remind

Also for the future, if you want a new review, just push the little icon next to the reviewer to re-request review (don't do it for me here though, as I have nothing to add here)

It can be confusing I know 🙂, but I hope you can see that just tagging someone without actually stating your intent (and assuming it's clear from assumptions) is a bit like just yelling "hey!" at someone

[dsnopek]

Thanks!

I don't know cmake very well, but it seems to be working as expected in my testing. I only have the one tiny bit of review, otherwise this seems fine to me. Ideally, it'd be nice for someone who is more knowledgeable with cmake to review it, but we don't have too many folks who are.

[dsnopek]

Other defines are added to the command-line without the space after -D, it'd be nice for that to be consistent:

Suggested change

	set(GODOT_COMPILE_FLAGS "${GODOT_COMPILE_FLAGS} -D HOT_RELOAD_ENABLED")
	set(GODOT_COMPILE_FLAGS "${GODOT_COMPILE_FLAGS} -DHOT_RELOAD_ENABLED")

[dsnopek]

This is fine, given that it looks like "Debug" and "Release" are the only options here. With scons, there's also the possibility of making editor builds, which is why the logic there is "not release" as opposed to checking directly for debug. I guess if we ever have editor builds via cmake, though, we'll need to change this.

[grabusr]

Please consider also Multiconfig generators like "Visual Studio ..." or NinjaMultiConfig where there is no CMAKE_BUILD_TYPE. Then you can use generator expression $