Declare `NSObject` in std/objc.sx as `#foreign #objc_class("NSObject")`
with the canonical instance + class-method surface every Obj-C class
inherits: `retain`/`release`/`autorelease`/`new`/`alloc`/`init`/
`description`/`hash`/`isEqual_`/`isKindOfClass_`/`respondsToSelector_`/
`class`. Root the foreign-class hierarchy in uikit.sx at NSObject by
adding `#extends NSObject;` to every previously-unrooted declaration
(NSValue, NSNumber, NSDictionary, NSSet, NSNotification, NSBundle,
NSNotificationCenter, NSRunLoop, CADisplayLink, CALayer, EAGLContext,
UIScreen, UIResponder) plus deeper chain fixes (NSMutableDictionary
extends NSDictionary; UIWindow extends UIView; UIViewController
extends UIResponder). After this, M2.3's extends-chain walk finds
`retain`/`release` on any UIKit-typed value:
view := UIView.alloc().init();
defer view.release(); // canonical sx idiom — no language magic
Plus `autoreleasepool(body: Closure())` stdlib helper that wraps
`body` in `objc_autoreleasePoolPush` / `defer objc_autoreleasePoolPop`.
Required for Foundation factory returns; closure-call frame is real
cost so hot loops should inline the push/defer-pop pattern manually.
Smoke test `ffi-objc-arc-01-autoreleasepool.sx` exercises both
patterns; refresh of two IR snapshots picks up the new stdlib decls
appearing in test outputs that include `modules/std/objc.sx`.
185/185 example tests pass; chess on iOS-sim green.
For every sx-defined #objc_class, emit a C-callconv +alloc IMP
that the Obj-C runtime calls when '[Cls alloc]' fires (from sx
code, UIKit instantiation, Info.plist principal class, etc.):
+alloc IMP (cls: Class, _cmd: SEL) -> id
instance = class_createInstance(cls, 0)
state = malloc(STATE_SIZE)
memset(state, 0, STATE_SIZE)
object_setIvar(instance, load(@__<Cls>_state_ivar), state)
return instance
STATE_SIZE = max(typeSizeBytes(state struct), 1) — always at
least one byte so the ivar is never null after +alloc returns.
The IMP is registered on the METACLASS (class methods live there
— every Class object's isa points to the metaclass) in emit_llvm's
class-pair init constructor:
metaclass = object_getClass(cls)
sel_alloc = sel_registerName("alloc")
class_addMethod(metaclass, sel_alloc, alloc_imp, "@@:")
That override wins over NSObject's default +alloc; runtime
instantiations get the __sx_state ivar bound automatically.
Per-instance allocator binding (the plan's full design — store
the Allocator value in the state struct so -dealloc frees through
the same one) is deferred. libc malloc/free is fine for v1; we'll
upgrade once Month 4's autoreleasepool + ARC ops shake out.
REFACTOR: collapsed five duplicate 'get<Name>Fid' helpers and
their cache fields (object_getIvar, object_setIvar,
class_createInstance, malloc, memset) into a single
'ensureCRuntimeDecl(name, params, ret) -> FuncId'. The helper
checks for an existing decl by name first (avoids the
'class_createInstance.1' duplicate-symbol crash when stdlib's
'#foreign' decl is already in the module). One helper instead
of one-per-function = ~150 lines deleted.
object_getIvar / object_setIvar added to stdlib std/objc.sx
so user code can use them too (146 exercises object_getIvar
to verify __sx_state was bound to a non-null state pointer
after +alloc).
146-objc-class-alloc-roundtrip.sx end-to-end against macOS:
'[SxFoo alloc]' returns non-null AND object_getIvar(instance,
__sx_state) returns the state ptr. Real Obj-C runtime, no
mocks.
175 example tests pass (+1). zig build test green.
Adds named stand-ins for the three opaque Obj-C runtime types
and Apple's signed-char boolean to library/modules/std/objc.sx:
id :: *void; // any Obj-C instance pointer
Class :: *void; // a class object pointer
SEL :: *void; // a registered selector
BOOL :: s8; // Apple's signed-char boolean (NOT sx's bool)
All resolve to their underlying type at the LLVM layer — no
runtime cost — but make foreign-class declarations read closer
to Objective-C source. The header's old caveat about lacking
type aliases is gone.
141-objc-type-aliases.sx exercises the aliases against the real
macOS Obj-C runtime: alloc/init an NSObject, fetch its class
via objc_getClass, sel_registerName a SEL, then call
'isKindOfClass:' returning BOOL=1. Non-macOS paths print the
same line to keep the snapshot stable.
DEFERRED (M1.1.b, follow-up): 'Class(T)' parameterization with
#extends-aware covariance, and 'instancetype' per-decl
substitution. Both require compiler-level type-check support
beyond plain stdlib aliases.
170 examples pass (+1).
Verify-step uncovered three categories of regressions where sx code
calls into the platform's C ABI through fn-pointer types or as a
registered callback. Every site now declares the right convention.
C-side calls INTO sx → callconv(.c) on the sx function:
- platform/android.sx: sx_android_render_thread_entry is the start
routine pthread_create invokes — pthread treats it as a C function.
Also annotate the pthread_create signature so the start-routine fn-
pointer field rejects mismatching sx fns at compile time.
sx code calling typed fn-pointers cast from C symbols → callconv(.c)
on the fn-pointer type:
- opengl.sx: 55 GL fn-ptr globals + load_gl's proc-loader param. GL
trampolines are macOS/iOS/Android system code.
- std/objc.sx: the two typed `objc_msgSend` casts.
- gpu/metal.sx: ~40 typed `objc_msgSend` casts across Metal command
encoder / device / pipeline construction.
The block invoke trampolines (objc_block.sx) call back INTO sx (the
closure trampoline). The typed fn-ptr there stays default-conv so
ctx prepends correctly. Compiler change: a callconv(.c) sx function
now binds `current_ctx_ref` to `&__sx_default_context` at entry (used
to be gated by `isExportedEntryName`). C-callable sx callbacks like
the block invokes don't get their own __sx_ctx param but their bodies
still need a real Context to forward to the closure they delegate to.
Tests: 152/152 example suite + chess green on all 3 platforms.
Screenshots at /tmp/sx-game-{macos,iossim,android}.png.
- examples/modules/ -> library/modules/ (top-level, no more
symlink hacks in consumer projects)
- compiler discovers stdlib via _NSGetExecutablePath / readlink
/proc/self/exe; searches dev layout (../../library), install
layout (../library), and alongside-binary fallback
- SX_STDLIB_PATH env var overrides for tests / dev convenience
- SX_DEBUG_STDLIB env var dumps the discovery results
- build.zig installs library/ alongside the binary
- Compilation gains stdlib_paths field threaded through resolveImports
- 50 tests pass; consumer projects can now build from any cwd
