User writes BOTH `main` and a 3-line `android_main(app)` trampoline.
The library provides `sx_android_bootstrap(app)` (stashes the NDK app
pointer into a platform-owned global) and `AndroidPlatform` impl of
the Platform protocol. The library NEVER references `main` — the OS-
shape entry symbol lives in user code where the other entry symbols
already live. iOS / SDL3 keep their existing shape; only Android adds
the trampoline.
Cross-cutting bits this commit ships:
library/modules/compiler.sx
Add `android` variant to `OperatingSystem`.
src/ir/lower.zig
- injectComptimeConstants: map TargetConfig.isAndroid() → .android.
- New Pass 4 `checkRequiredEntryPoints`: emit a clean diagnostic
when `--target android` is requested but `android_main` isn't
defined, instead of letting the user crash on a dlopen-time
missing-symbol error.
library/modules/platform/android.sx
AndroidPlatform impl of the Platform protocol — EGL bringup on
`APP_CMD_INIT_WINDOW`, ALooper(0) polling, dispatches the user's
frame closure each ~16 ms tick. `sx_android_bootstrap(app)` is the
only function exposed for the entry trampoline.
examples/99-android-egl-clear.sx
Rewritten to use the new pattern: minimum `main` + `android_main`
pair, AndroidPlatform-driven render loop. Doubles as the usage
reference users hand off to the compiler diagnostic.
Verified on Pixel 7 Pro: purple clear-color frame, periodic
`rendered 60 frames` logcat lines. iOS-sim chess + 86/86 regression
tests pass.
Verified on Pixel 7 Pro: solid purple frame, 'rendered 60 frames'
logcat line every second. End-to-end exercise of the new
sx-build → libsxhello.so → APK toolchain shipped today: NDK clang
link + native_app_glue bundling + aapt2/zipalign/apksigner pipeline +
isExportedEntryName so android_main lands in .dynsym.
Notes the source captures so future Android work doesn't repeat the
debugging:
- android_app field offsets for arm64 NDK 29 (window @ 72,
destroyRequested @ 100, source process fn-ptr @ 16).
- ALooper_pollOnce(-1, ...) blows the stack inside Looper::pollOnce
on this device/OS combo; ALooper_pollOnce(0, ...) is fine. We
drive the event loop non-blocking and sleep 16ms.
Outside the regression set on purpose (no tests/expected/99-*.txt) —
same convention as 63-metal-clear.sx. Build instructions live in the
file's leading comment.
