Implements https://github.com/godotengine/godot-proposals/issues/3371.
New `target` presets
====================
The `tools` option is removed and `target` changes to use three new presets,
which match the builds users are familiar with. These targets control the
default optimization level and enable editor-specific and debugging code:
- `editor`: Replaces `tools=yes target=release_debug`.
* Defines: `TOOLS_ENABLED`, `DEBUG_ENABLED`, `-O2`/`/O2`
- `template_debug`: Replaces `tools=no target=release_debug`.
* Defines: `DEBUG_ENABLED`, `-O2`/`/O2`
- `template_release`: Replaces `tools=no target=release`.
* Defines: `-O3`/`/O2`
New `dev_build` option
======================
The previous `target=debug` is now replaced by a separate `dev_build=yes`
option, which can be used in combination with either of the three targets,
and changes the following:
- `dev_build`: Defines `DEV_ENABLED`, disables optimization (`-O0`/`/0d`),
enables generating debug symbols, does not define `NDEBUG` so `assert()`
works in thirdparty libraries, adds a `.dev` suffix to the binary name.
Note: Unlike previously, `dev_build` defaults to off so that users who
compile Godot from source get an optimized and small build by default.
Engine contributors should now set `dev_build=yes` in their build scripts or
IDE configuration manually.
Changed binary names
====================
The name of generated binaries and object files are changed too, to follow
this format:
`godot.<platform>.<target>[.dev][.double].<arch>[.<extra_suffix>][.<ext>]`
For example:
- `godot.linuxbsd.editor.dev.arm64`
- `godot.windows.template_release.double.x86_64.mono.exe`
Be sure to update your links/scripts/IDE config accordingly.
More flexible `optimize` and `debug_symbols` options
====================================================
The optimization level and whether to generate debug symbols can be further
specified with the `optimize` and `debug_symbols` options. So the default
values listed above for the various `target` and `dev_build` combinations
are indicative and can be replaced when compiling, e.g.:
`scons p=linuxbsd target=template_debug dev_build=yes optimize=debug`
will make a "debug" export template with dev-only code enabled, `-Og`
optimization level for GCC/Clang, and debug symbols. Perfect for debugging
complex crashes at runtime in an exported project.
This change implements dynamic loading of the OpenXR Loader library
on Android. If an OpenXR Loader library is not found,
Godot will still function with OpenXR disabled.
Also, on every platform, the OpenXR symbols are resolved at runtime
using xrGetInstanceProcAddr.
On Windows and Linux the OpenXR loader is included in the main
engine binary.
On Android, the OpenXR Loader is not built with the engine. Separately
distributed Android plugins will be provided with the correct loader
library for each device.
Co-authored-by: Gábor Pál Korom <gabor.p.korom@migeran.com>
Co-authored-by: Gábor Koncz <gabor.koncz@migeran.com>
Now the `linuxbsd` platform can be built headlessly (e.g. without X11
development libraries).
I also cleaned up some weird (old?) usages of the `env` variable which
seem to make no difference and are used nowhere else.
