Add optional `detect.py` `get_tools` method to let platforms register SCons
tools they need.
This helps move this logic out of SConstruct, keeping platforms more self
contained, and helping thirdparty platforms define their own custom tools.
This logic was also unreliable (the `use_mingw` one would only work if
passed manually on the command line, not in e.g. `get_flags`).
Co-authored-by: Thaddeus Crews <repiteo@outlook.com>
This speeds up build time considerably for these platforms compared to
using `lto=full`, which is sadly single-threaded with LLVM, unlike GCC.
Changes to default behavior of `lto=auto` (i.e. `production=yes`):
- Linux: Prefer ThinLTO for LLVM
- Web: Prefer ThinLTO
- Windows: Prefer ThinLTO for llvm-mingw
The following LLVM targets don't use LTO by default currently, which
needs to be assessed further (gains from LLVM LTO on performance need
to be weighed against the potential size increase from heavy inlining):
- Android
- iOS
- macOS
- Windows clang-cl
They are not supported anyway, emscripten has an emulation layer that
implements them over WebSocket/WebRTC, which is really surprising for
users, and also not very useful since we have proper WebSocket and
WebRTC support.
This can make the build smaller, if we also disable the UPNP module
(which will otherwise include a third party library referencing "socket"
thus forcing emscripten to include the compatibility layer)
The offending symbol gets stripped away by wasm-dce but it's used on the
JavaScript side and causes and undefined symbol which also causes the
closure compiler to throw an error.
SUPPORT_LONGJMP have changed since emscripten 3.1.32 to default to
"wasm" mode when exceptions are enabled, and "emscripten" mode when
disabled.
While we generally doesn't use exception in core, linked libraries may
need them, and emscripten don't plan to support WASM EH + Emscripten
SjLj in the long term.
- Set `-sSTACK_SIZE` to what it was before emscripten 3.1.27.
It was renamed in 3.1.25 so also set `-sTOTAL_SIZE` for older
versions for consistency.
- Set `-sDEFAULT_PTHREAD_STACK_SIZE` to what it was before 3.1.30.
Co-authored-by: Rémi Verschelde <rverschelde@gmail.com>
When using proxy_to_pthread we add BIGINT support (to support exchanging
64 bits integers between wasm and JS).
Bigint though, is part of ECMAScript 2020, and the closure compiler was
using ECMAScript 6 instead.
This commit update the CC configuration to use ECMAScript 2020 instead.
This fixes multiple issues/inconsistencies around `get_compiler_version()`:
* With no shell allocated, launching the compiler could fail even
with proper paths being set.
* The return value was described as "an array of version numbers as ints",
but the function actually returned a `Dictionary` (or `None`).
* Not all calls were properly handling a `None` return value in case of errors.
On Windows this broke compiling for me since #81869 with default settings.
* Some calls defined inconsistent defaults/fallbacks (`0` or `-1`).
This means no CPU occlusion culling (and not compiling Embree), unless
you compile custom export templates with `module_raycast_enabled=yes`.
This reduces the memory footprint significantly, and binary size.
Fixes#70621.
Co-authored-by: Hugo Locurcio <hugo.locurcio@hugo.pro>
Upon investigating the extremely slow MSVC build times in #80513, I noticed
that while Godot policy is to never use exceptions, we weren't enforcing it
with compiler flags, and thus still included exception handling code and
stack unwinding.
This is wasteful on multiple aspects:
- Binary size: Around 20% binary size reduction with exceptions disabled
for both MSVC and GCC binaries.
- Compile time:
* More than 50% build time reduction with MSVC.
* 10% to 25% build time reduction with GCC + LTO.
- Performance: Possibly, needs to be benchmarked.
Since users may want to re-enable exceptions in their own thirdparty code
or the libraries they compile with Godot, this behavior can be toggled with
the `disable_exceptions` SCons option, which defaults to true.
This hugely reduces the number of exports, making it acceptable for
browsers.
Note that dlink + threads is still not working due to upstream issues
with the pthread emulation library.
Should hopefully be solved once emscripten move to native WASM threads.
