New `.jni_msg_send` IR opcode carrying `{env, target, name, sig,
args[], is_static}`. `lowerFfiIntrinsicCall` now dispatches on
`fic.kind`: `.objc_call` keeps the existing path; `.jni_call` and
`.jni_static_call` route through `lowerJniCall`, which emits the new
opcode.
emit_llvm.zig expands `.jni_msg_send` into the JNI vtable
indirection:
%ifs = load ptr, %env ; vtable
%get_obj_class = load ptr, gep(%ifs, i32 31)
%cls = call ptr %get_obj_class(%env, %target)
%get_method_id = load ptr, gep(%ifs, i32 33)
%mid = call ptr %get_method_id(%env, %cls, %name, %sig)
%call_void_method = load ptr, gep(%ifs, i32 61)
call void %call_void_method(%env, %target, %mid, args...)
Per step 1.15's scope: only `.jni_call` (instance) + `void` return
are wired through the switch. `.jni_static_call` (1.23) and the
non-void returns (1.18–1.22) drop to a placeholder `LLVMGetUndef` so
the build doesn't fault — the next-step commits flip those arms one
shape at a time. Method-ID caching is step 1.17.
Two small helpers landed alongside:
- `loadJniFn(ifs, offset, name)` — GEP into the vtable + load.
- `extractSlicePtr(val)` — string literals lower as `{ptr, i64}`
slices in sx IR; JNI's `GetMethodID` expects raw C strings, so
this extracts field 0 when the source is a slice.
Android cross-compile now passes for `examples/ffi-jni-call-02-void.sx`
(2/2 cross targets green). Host run_examples still passes 112/112.
Chess iOS-sim + Android both compile clean.
`collectCaptures` in `src/ir/lower.zig` was the closure free-variable
analyzer that decides which names from a closure body need to be
boxed into the env struct at lambda-build time. Its switch on AST
node kind enumerated every other shape (`.call`, `.if_expr`,
`.match_expr`, `.for_expr`, etc.) but no arm for `.ffi_intrinsic_call`,
so the trailing `else => {}` quietly dropped its `args[]` and
`return_type` walks. Names referenced inside `#objc_call(T)(recv,
"sel:", ...)` from a closure body never made it into the captures
list, so when lowering bound the closure scope from env, those names
came back as "unresolved".
The fix adds the missing arm — walk `return_type` and every `args[i]`
the same way `.call` walks `callee` + `args`.
Companion changes:
- `examples/issue-0038.sx` → `examples/103-ffi-closure-capture.sx`
(out of the open-issue namespace; comment header tightened to
describe the feature, not the historical bug).
- `examples/ffi-objc-call-09-in-construct.sx` drops the
`g_hasher_recv` module-global workaround that was added for this
bug — the closure now captures `recv` from `make_hasher`'s arg
list normally.
109/109 regression tests pass; chess Android + iOS-sim still
build clean.
Root cause: sx's `xx <ptr>` cast targeting an integer type
(common pattern: `xx u64 = xx @some_global`) lowered to a no-op
because `coerceToType` had branches for int↔float and same-kind
widen/narrow, but nothing for pointer↔integer. The cast left the
value as a pointer Ref, and `emitInst`'s `.ret` arm tried to
coerce a `ptr` value to an `i64` slot — coerceArg had no
ptr↔int branch either, fell through to undef.
Why it worked in main but failed in helpers: an
`alloca u64`+`store ptr @g, alloca`+`load i64, alloca` sequence
preserves the address bits as raw memory, so the
"store-then-load through an alloca" workaround happened to do
the right thing without a real cast. A `ret i64 <ptr>` has no
such intermediate slot and triggers an LLVM type mismatch.
Fix layered into two existing IR opcodes:
lower.zig (coerceToType):
new branch — when src and dst types are ptr↔int, emit a
`bitcast` IR opcode with the right from/to. Mirrors how
int↔float emits `.int_to_float` / `.float_to_int`.
emit_llvm.zig (.bitcast arm):
dispatch ptr→int to `LLVMBuildPtrToInt` (+ trunc/zext if the
target int width != 64), int→ptr to `LLVMBuildIntToPtr`. The
"real bitcast" path stays for same-kind type punning.
Modern LLVM's BuildBitCast rejects ptr↔int directly, hence
the dispatch.
The fix also closes a quiet behavior gap that affected non-`#foreign`
globals (any `xx @<global>` from a helper fn). Surfaced while
investigating issue-0037; verified independently with a
non-`#foreign` sx-side global of type `s64`.
File mechanics: issue-0037 promoted to a focused feature example
per CLAUDE.md's resolution flow:
examples/issue-0037.sx -> examples/102-foreign-global-from-helper.sx
tests/expected/issue-0037.{txt,exit} -> tests/expected/102-foreign-global-from-helper.{txt,exit}
ffi-objc-call-03 + ffi-objc-call-06 IR snapshots updated to
reflect the ptr→int store-via-ptrtoint shape that's now correct
at the LLVM-IR level (same bits in memory, but properly typed).
102/102 regression tests pass; chess Android + iOS-sim still build
clean. `ffi-objc-call-04-primitive-returns` flips from xfail to
passing with both nil-recv and real-recv flavors of *void / s64
returns exercised.
Key change: a new `objc_msg_send` IR opcode bundles (recv, sel,
extra args) and carries the return type via the `Inst.ty` field.
emit_llvm.zig builds a per-call-site LLVM function type from the
argument Refs' IR types (recv/sel as ptr; extra args through
abiCoerceParamType) and dispatches with LLVMBuildCall2. One
declared `@objc_msgSend` symbol is reused across every return
type — opaque pointers make the function value type-erased, so
each call site picks its own ABI.
before: one (recv, sel) -> ptr LLVM declaration, hard-coded
per call site; only void return wired in 1.3.
after: same declaration, each call site provides a fresh
LLVMBuildCall2 fn-type → s64 / *void / bool / f64
returns all dispatch correctly without separate FuncIds.
Selector init mechanism: stayed with the @llvm.global_ctors
constructor. Investigated clang's
`__DATA,__objc_selrefs` + `externally_initialized` shape — works
for fully-linked binaries (dyld substitutes the SEL at load
time) but **LLVM ORC JIT** (the engine behind `sx run`) doesn't
process Mach-O Obj-C metadata sections, so the slot keeps its
initial value (the method-name string pointer) and dispatch
crashes with "<null selector>". The portable choice: keep the
constructor AND inject a direct call to it at `main`'s entry —
idempotent under dyld (sel_registerName returns the same SEL on
re-registration), required for ORC JIT.
Files touched:
src/ir/inst.zig | new ObjcMsgSend struct + opcode
src/ir/lower.zig | drop the void-only restriction; emit the
new opcode; remove the orphaned
getObjcMsgSendFid path (objc_msgSend
declaration moved to emit_llvm)
src/ir/emit_llvm.zig | objc_msg_send arm (per-call-site
LLVMBuildCall2); lazy `@objc_msgSend`
declaration via getObjcMsgSendValue;
emitObjcSelectorInit refactored to inject
the ctor call at main's entry
src/ir/{print,interp}.zig | switch arms for the new opcode
`ffi-objc-call-03-selector-sharing.ir` snapshot updates to
reflect the new shape (the `call ... @objc_msgSend` call sites
no longer mention a typed wrapper).
101/101 regression tests pass; the IR snapshot for the selector-
sharing test diff flips from four per-call `sel_registerName` calls
to two (one per unique selector) routed through a module-init
constructor — matching what clang emits for `@selector(...)`.
Hot-path cost collapses from a libobjc hashtable lookup per call to
a single load of a static `SEL*` slot:
Before (Phase 1.3):
%sel = call ptr @sel_registerName(<"init">)
call ptr @objc_msgSend(<recv>, %sel)
After (Phase 1.5):
%sel = load ptr, ptr @OBJC_SELECTOR_REFERENCES_init
call ptr @objc_msgSend(<recv>, %sel)
+ @OBJC_SELECTOR_REFERENCES_init = internal global ptr null
+ @OBJC_SELECTOR_REFERENCES_release = internal global ptr null
+ define internal void @__sx_objc_selector_init() {
+ %sel = call ptr @sel_registerName(ptr @OBJC_METH_VAR_NAME_)
+ store ptr %sel, ptr @OBJC_SELECTOR_REFERENCES_init
+ %sel1 = call ptr @sel_registerName(ptr @OBJC_METH_VAR_NAME_.2)
+ store ptr %sel1, ptr @OBJC_SELECTOR_REFERENCES_release
+ ret void
+ }
+ @llvm.global_ctors = appending global [1 x { i32, ptr, ptr }]
+ [{ ..., ptr @__sx_objc_selector_init, ptr null }]
Implementation:
module.zig | new `objc_selector_cache: ArrayList(ObjcSelectorEntry)`
with `lookupObjcSelector` / `appendObjcSelector`. List
(not hashmap) keeps emit order stable across builds so
the IR snapshot doesn't flicker on rehash.
lower.zig | `internObjcSelector(sel)` creates the slot on first
use, returns the same `GlobalId` on every subsequent
call to the same selector. lowerFfiIntrinsicCall now
emits `global_addr + load` for literal selectors.
Non-literal selectors keep the `sel_registerName`
fallback. Declaring `sel_registerName` lazily on
first intern so emit_llvm finds it for the
constructor body.
emit_llvm.zig | new `emitObjcSelectorInit` pass synthesizes a void
constructor that loops over the cache, calls
`sel_registerName` for each unique selector string,
stores the result in the slot. Constructor is
registered in `@llvm.global_ctors` with default
priority (65535) so dyld runs it before main.
The `@OBJC_METH_VAR_NAME_` private string globals and unnamed-addr
flag match clang's exact emission shape — picked up by the system
linker into the right Mach-O sections on macOS / iOS. Chess
Android + iOS-sim still build clean (no `#objc_call` in chess yet —
phase-3 migration will start exercising this).
100/100 regression tests pass; ffi-objc-call-02-void-return flips
from xfail (codegen rejection) to passing ("ok").
Lowering for `#objc_call(void)(recv, "selector:")` lands in
lower.zig as `lowerFfiIntrinsicCall`:
%sel = call ptr @sel_registerName(<"selector:">)
%call = call ptr @objc_msgSend(<recv>, %sel)
Two extern decls (`sel_registerName(*u8) -> *void` and
`objc_msgSend(*void, *void) -> *void`) are declared lazily and
cached on the Lowering instance via `objc_msg_send_fid` /
`sel_register_name_fid`, so multiple call sites share one
declaration each.
Phase 1.3 deliberately keeps scope tight: only `void` return + just
(recv, selector) arity is wired. Non-void returns + variadic arity
fall through with a diagnostic and are owned by subsequent phase-1
steps (1.6 primitive returns; 1.7..1.9 struct shapes; 1.10 multi-
keyword selectors).
Selector resolution is still per-call-site `sel_registerName` —
the planned 1.5 interning turns the per-call hashtable lookup into
a single static-global load. Chess Android + iOS-sim builds clean
— no regression on the existing typed-`objc_msgSend`-cast pattern.
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.
When lowering `self.cb()` from inside a method whose receiver is *Self,
the field-access path passed the receiver pointer (not the aggregate)
to `structGet`, which then produced `call void undef(ptr undef)` at
the LLVM level — undefined at runtime, corrupted adjacent globals when
it transferred control to a garbage pointer. Auto-load through the
pointer first so structGet receives a real aggregate.
Discovered while building the new AndroidPlatform's `run_frame_loop` —
calling the stored frame closure as `self.frame_closure()` zeroed
out adjacent globals because the undef call jumped into random memory.
Added examples/100-closure-field-call-via-self-ptr.sx as the locked-in
regression: both direct (`self.cb()`) and hoisted (`fn := self.cb; fn();`)
forms must yield identical IR + behavior. 86/86 regression tests pass.
Android (toolchain):
--target android / --target android-arm64 → aarch64-linux-android21.
target.zig discovers $ANDROID_NDK_HOME (or scans
~/Library/Android/sdk/ndk/* for the newest), invokes the NDK clang
with -shared -fPIC and links libsxhello.so against -llog -landroid
-lEGL -lGLESv3 -lm -ldl. native_app_glue.c from the NDK is compiled
and linked alongside the sx .o so apps can use the conventional
android_main(struct android_app*) shape; -u ANativeActivity_onCreate
keeps glue's symbol live.
Android (APK):
--apk <out> wraps the .so into a debug-signed installable APK.
target.zig discovers the SDK at $ANDROID_HOME (or
~/Library/Android/sdk), picks the newest build-tools + platforms,
generates a NativeActivity AndroidManifest.xml from --bundle-id,
packages via aapt2 link, appends the lib/ tree, zipalign, then
apksigner against ~/.android/debug.keystore (auto-generated via
keytool on first use). One command end-to-end:
sx build --target android --apk out.apk \\
--bundle-id co.swipelab.foo main.sx
Verified on Pixel 7 Pro: install + launch reaches android_main.
Compiler (entry-point linkage):
Top-level fn defs default to LLVM internal linkage and are lazily
lowered (only `main` was eagerly lowered before). Added
isExportedEntryName() — a small allowlist for names the OS loader
calls: `main`, `android_main`, `ANativeActivity_onCreate`,
`JNI_OnLoad`. These get eagerly lowered AND keep external linkage,
so they actually land in .dynsym.
LSP (imports):
DocumentStore now takes the install-discovered stdlib_paths and
forwards them into resolveImportPath, mirroring the compiler. Before
this, every `#import "modules/..."` resolved through the stdlib path
failed silently inside the LSP and identifiers from those modules
showed as `undefined variable`. Repro on label.sx: 1 false positive
before, 0 after.
Protocol structs registered via registerProtocolDecl carry a new
is_protocol flag; the ?T paths in sizeOf/typeSizeBytes/toLLVMType
recognise it and lay out ?Protocol as the protocol struct itself
(ctx == null IS the "none" state), matching how ?Closure / ?*T are
sentinel-shaped — no extra storage.
Method dispatch on ?Protocol auto-unwraps in lowerCall's field-access
path; the unwrap is structurally a no-op so we just rebind obj_ty to
the payload type. resolveCallParamTypes extended for optional-protocol
receivers so enum-literal args (gpu.create_texture(.r8, ...)) get the
right target_type and don't silently collapse to tag=0 : s32 — same
issue-0031-class bug closed in Session 66, one type-system layer
deeper.
Library: UIRenderer / UIPipeline / GlyphCache migrated from the verbose
gpu: GPU = ---; has_gpu: bool pattern to gpu: ?GPU = null. set_gpu no
longer maintains a parallel bool flag.
Bundled: dock.sx threads delta_time as a struct field rather than via
a global pointer (cleanup unrelated to issue-0028, committed alongside).
Verified: 85/85 regression tests pass; iOS-sim chess + macOS chess
both render correctly post-migration.
Four root causes for "chess UI shows white screen" — all fixed:
1. Hybrid legacy-app + scene-API path on iOS 26. Without
UIApplicationSceneManifest in the Info.plist, iOS 26 booted us in
[rb-legacy] mode and -[UIApplication connectedScenes] returned an
empty set. didFinishLaunching's window-setup code bailed at "no scene"
and the UIWindow never appeared on screen. Fix: emit the manifest in
buildInfoPlist (src/target.zig) AND split the window/view/layer setup
from didFinishLaunching into a new SxSceneDelegate's
scene:willConnectToSession:options: IMP. didFinishLaunching now just
subscribes the keyboard observer and returns YES.
2. UISceneDelegate formal protocol conformance. iOS 26 checks
-[cls conformsToProtocol:@protocol(UISceneDelegate)] before
instantiating the scene delegate; without it the runtime logs
"SxSceneDelegate does not conform to the UISceneDelegate protocol"
and silently uses a default delegate that does nothing. Fix:
look up UISceneDelegate + UIWindowSceneDelegate via objc_getProtocol
and class_addProtocol BEFORE objc_registerClassPair. The protocol
metadata is present at link time (unlike UIApplicationDelegate per
the long-standing legacy note in CHECKPOINT).
3. Protocol method return types via type aliases lowered as void.
The GPU protocol declares `create_shader(...) -> ShaderHandle` where
`ShaderHandle :: u32`. The protocol-decl lowering at lower.zig:7547
passed the return AST node through type_bridge.resolveAstType which
doesn't know about the type_alias_map. resolveTypeName fell through
to its "assume named struct" branch and registered ShaderHandle as
an empty struct ({ }). LLVM IR for the protocol call_indirect then
read `call {} %fn_ptr(...)` — return value discarded; the
subsequent abi.coerce load from a zero-init'd alloca yielded 0.
Symptom: UIRenderer.mtl_shader = 0, set_shader sees state == null,
the render-encoder fires draw with no pipeline state bound, GPU
rejects the command buffer with MTLCommandBufferErrorInternal.
Fix: at the protocol-decl method-type resolution sites in
lower.zig, check type_alias_map BEFORE falling through to
type_bridge.resolveAstType for both params and return type. A
chess-side companion fix in /Users/agra/projects/game/main.sx
(separate commit) memsets the MetalGPU struct after alloc so the
List(*void) fields' len/cap/items aren't garbage.
After all four (this commit + memset companion in chess repo):
- 71/71 regression tests pass.
- Chess game now boots, scene-connects, ticks CADisplayLink, renders
dark-gray clear + UI text + panel dividers every frame on iOS sim.
- Metal-clear example still renders.
Chess board + pieces visual contrast and faint-text-color are remaining
visual-polish items, not compiler/platform-setup issues.
Three stacked compiler bugs were causing iOS-sim chess to crash inside
[MTLTexture replaceRegion:...]. Fixing them lets every replaceRegion call
site succeed (1×1 RGBA8, 1MB R8 atlas, 440×440 chess pieces).
Path B for callconv(.c) fn-pointer casts:
- FunctionInfo now carries call_conv: CallConv (TypeInfo.CallConv) so
function-type interning distinguishes sx-CC from C-CC. Inst.zig's
Function.CallingConvention aliases the same enum.
- Parser accepts an optional `callconv(.c)` suffix on fn-pointer type
spellings (factored into parseOptionalCallConv() shared with parseFnDecl
and parseLambda).
- resolveFunctionType passes the parsed CC through functionTypeCC().
- .call_indirect reads fp.call_conv == .c and applies the C-ABI
alloca+materialize for >16B aggregate args (Path A's behaviour at .call).
Apple ARM64 ABI (drop LLVM byval):
- Side-by-side asm diff vs clang's emission for the equivalent C call site
showed LLVM's `byval` attribute lowers Apple-arm64 byval on the stack,
while clang passes the struct via a pointer in the next int register
(x2 for replaceRegion:). The runtime objc_msgSend dispatch path expects
clang's convention.
- Dropped the byval attribute from the function-signature emission and
from both call sites (.call and .call_indirect). The materialize-into-
alloca + pass-plain-ptr pattern stays — the call site now matches
clang's `mov x2, sp` exactly.
- Path A's sx-to-sx case continues to work since both ends use plain ptr
(caller does alloca+store+pass, callee loads from the ptr in prologue).
Protocol dispatch (emitProtocolDispatch):
- Untargeted `null` lowers as const_null with type .void (per
target_type orelse .void). The "wrap-value-in-alloca-pass-pointer"
branch alloca'd a void slot, which LLVM's IRBuilder asserts on —
EXC_BREAKPOINT in getTypeSizeInBits, manifesting as exit 133 / SIGTRAP
when building the chess game. Fixed by re-emitting as
constNull(void_ptr) when arg_ty == .void && expected_ty == void_ptr.
- is_pointer_ty only recognized .pointer, so [*]T (many_pointer) was
alloca-wrapped — the heap pixels pointer from stbi_load was stored
into a stack slot and the slot's address was passed as the *void arg.
Fixed by extending the check to `.pointer or .many_pointer`.
metal.sx call sites + lifecycle guards:
- msg_replace (replaceRegion:, MTLRegion = 48B) and the two setScissorRect:
sites (MTLScissorRect = 32B) now spell their fn-pointer types with
by-value params + callconv(.c) — the *MTLRegion/@local workaround is
gone.
- metal_begin_frame_ios bails before nextDrawable when pixel_w/h are 0
(drawableSize 0×0 makes nextDrawable abort via XPC).
- metal_init_ios only sets drawableSize when dims are positive.
- begin_frame's encoder/cmd_buffer failure paths now clear self.drawable
so a partial failure doesn't leak a drawable back into the pool.
Examples + tests:
- examples/86-callconv-c-fnptr-large-aggregate.sx — new, covers Path B
with C-CC fn-ptr cast.
- examples/87-fnptr-cast-large-aggregate.sx — renamed from issue-0025.sx,
covers Path B with default sx-CC (the negative case).
- examples/85-cc-c-large-aggregate.sx — from Session 60, covers Path A.
- examples/issue-0014.sx, issue-0024.sx, issue-0025.sx — removed
(resolved earlier this work).
71 regression tests pass, 0 failed. Chess game builds clean for iOS sim
and reaches its frame loop without aborting. Runtime: chess UI still
doesn't render — remaining issue is in the UIKit lifecycle / CAMetalLayer
setup (legacy-app vs scene-API hybrid), not a compiler bug. See
current/CHECKPOINT.md "Next step" for the diagnosis + options.
Phase 8 step 3a of the Metal renderer port:
- New library/modules/gpu/ with types.sx (handles + ClearColor +
TextureFormat enum), api.sx (GPU :: protocol { ... } covering the
lifecycle / per-frame / resource / per-draw surface), and metal.sx
(MetalGPU backend implementing the protocol against CAMetalLayer).
Resource handles are 1-based indices into backend List(*void) tables.
MTL aggregates >16 bytes (MTLRegion, MTLScissorRect) pass via *T to
match arm64 Apple's indirect-by-reference ABI; MTLClearColor + CGSize
go through the HFA path as direct fn-pointer casts on objc_msgSend.
- UIKitPlatform got a gpu_mode: GpuMode toggle + sibling SxMetalView
class registration. In metal mode init skips EAGL context, the
did_finish_launching IMP skips the EAGL drawable-properties dict,
layoutSubviews reads the layer's bounds * dpi_scale into pixel_w/h
instead of allocating a GL renderbuffer, and end_frame is a no-op
(the MetalGPU owns its own present).
- examples/63-metal-clear.sx verifies the pipeline end-to-end on iOS
sim — compiles a pass-through MSL shader (packed_float2/packed_float4
to avoid alignment padding), uploads 3 vertices, draws a colored
triangle on a dark-blue clear.
Compiler fixes (filed-and-fixed in this branch):
- inline if X { return E; } followed by a fall-through final expression
no longer emits two terminators into the same basic block. Verified
by examples/83-inline-if-return-fallthrough.sx.
- Top-level type alias Name :: u32; now resolves correctly as the type
annotation on a global variable (was treated as ptr {}, breaking
comparisons + initializers). Verified by examples/84-global-type-alias.sx.
Issue->feature promotion:
- 16 historical examples/issue-NNNN.sx repros now confirmed-fixed and
renamed to focused feature names (67-82). Each gains a
tests/expected/*.txt + .exit pair so the regression suite covers them.
- 5 stale issue repros deleted (subsumed by broader tests).
Regression suite: 68 passing, 0 failed. macOS chess builds + runs; wasm
chess builds; iOS sim GLES chess still renders the full board; iOS sim
Metal demo renders the triangle.
