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.
