Latent bug from the stdlib-path resolution introduced in 4849cfb.
The earlier shape captured `const ci = decl.data.c_import_decl;`
BEFORE mutating `decl.data.c_import_decl.{sources,includes}` with
the resolved paths, then passed the stale `ci.includes` to
`c_import.processCImport`. Result: `#include "vendors/..."` paths
that resolved via the stdlib branch (i.e. only existed under
sx/library/vendors/) reached clang as the original unresolved
string and failed to parse — silently producing no synthesized
`#foreign` decls.
`#source` survived because the source list is re-read from
decl.data later (collectCImportSources walks the AST), so it
picked up the mutated value. Only `#include`'s synthesis path was
broken.
Fix: do the resolution first inside its own scope, then re-bind
`ci` from `decl.data.c_import_decl` so the include list passed to
processCImport sees the resolved paths.
Caught by ffi-07 baseline (next commit) — the test deliberately
puts its C helper only under library/vendors/ so the path is
findable solely via the stdlib chain.
Foreign functions that return a >16-byte non-HFA aggregate (e.g.
Big24 / UIEdgeInsets on iOS / clang-shaped struct returns) need the
indirect-return ABI: caller allocates space, passes its pointer as a
hidden first arg with `sret(<T>)`, callee writes through it and
returns void. AAPCS64 puts the pointer in x8; SysV AMD64 puts it in
the first int register and treats the named return as void.
The existing >16-byte branch in `abiCoerceParamType` was returning
`ptr` for BOTH params and returns. That works for byval params (the
established pattern — caller alloca + store + pass ptr, callee loads
in prologue), but is wrong for returns: it caused the function decl
to look like `ptr @fn(...)` rather than `void @fn(ptr sret(<T>), ...)`,
and the call site read whatever happened to be in x0 as a struct
pointer — segfault on dereference (caught while writing the ffi-03
baseline).
Fix layered into the same `abiCoerceParamType` / call-site code path:
emitFunctionDecl:
- Compute `uses_sret = needs_c_abi && needsByval(ret_ty, raw_ret_ty)`.
- Ret type collapses to void.
- Prepend a `ptr` param at slot 0.
- Add `sret(<RetType>)` type attribute on param-index 1
(LLVMAttributeIndex 1 = first parameter; 0 = return value).
.call lowering:
- Detect callee_uses_sret via the same predicate.
- Allocate the result on the caller's stack (`sret.slot`).
- Prepend it as args[0] (with sret_off index alignment so the
original sx args land at args[1..]).
- After LLVMBuildCall2, set the same `sret(<T>)` attribute on
the call site's arg 1 (mirrors the fn-decl attribute — both
land in the AArch64 backend's lowering pass).
- Load the result from the slot to produce the IR value.
`call_indirect` (function-pointer dispatch — uikit.sx's typed
`objc_msgSend` casts) keeps its existing behavior for now; the iOS
path already round-trips UIEdgeInsets via that route. Folding the
same sret transform into call_indirect is a follow-up.
89/89 regression tests still pass. Chess Android + iOS-sim both
build clean.
Resolves issue-0036 (LLVM verifier failure on 16-byte integer-only
struct by value through #foreign). The mismatch:
Call parameter type does not match function signature!
%load = load { i64, i64 }, ptr %alloca, align 8
[2 x i64] %call = call [2 x i64] @fn({ i64, i64 } %load)
`abiCoerceParamType` had already chosen `[2 x i64]` for 9..16-byte
non-HFA structs (the AAPCS64 / SysV AMD64 register-pair ABI slot for
that size class) on the foreign-decl side, but `coerceArg` only knew
how to bridge struct<->integer (the ≤8 B case) — not struct<->array.
LLVM's verifier rejects type-mismatched call args, so the call site
never landed.
Added the symmetric branches in coerceArg:
- Struct -> Array : alloca <array>; store <struct>; load <array>
- Array -> Struct : alloca <array>; store <array>; load <struct>
Both use the LLVM opaque-pointer memory-bitcast pattern already in
place for the integer case. They're paired with the existing
i64 <-> small-struct bridge so all four (≤8 B int, 9..16 B int,
16 B HFA, >16 B byval) ABI slots round-trip cleanly through
emit_llvm now.
File mechanics: promotes the issue-0036 repro to a focused feature
example per CLAUDE.md's issue-resolution workflow:
examples/issue-0036.sx -> examples/101-ffi-medium-struct.sx
tests/expected/issue-0036.{txt,exit} -> tests/expected/101-ffi-medium-struct.{txt,exit}
vendors/issue_0036/issue_0036.c -> vendors/ffi_medium_struct/ffi_medium_struct.c
Snapshot updated to the passing output. 89/89 regression tests pass;
chess Android build still clean.
Four Android UX wins landing together; all verified end-to-end on a
Pixel 7 Pro (board fills width, info-panel text renders, status bar
inset honored, tap-to-select + tap-to-move plays 1. e4).
- AndroidPlatform.init reads density via AConfiguration_getDensity
(app->config at offset 32) and sets dpi_scale = density / 160. The
hardcoded 1.0 had been making every logical unit equal one physical
pixel; ChessBoardView's 520-default size_that_fits fallback then
rendered at ~half the framebuffer width on the device, and glyphs
rasterized at literal 11-13 physical pixels were essentially invisible
on a 2340-tall display.
- gles3.sx set_scissor un-stubbed; with dpi_scale right the renderer
feeds in valid pixel bounds and the Y-flip math lands inside the
framebuffer.
- New library/vendors/sx_android_jni/sx_android_jni.c walks
activity -> window -> decorView -> rootWindowInsets via JNI and
publishes the system-bar insets. safe_insets() lazy-queries the
first call after EGL is up (decor view isn't attached at bootstrap).
- sx_android_install_input_handler sets app->onInputEvent; sx-side
sx_android_input_event translates AMotionEvent DOWN/MOVE/UP/CANCEL
into existing mouse_down/mouse_moved/mouse_up Events so the chess
board's tap-to-select + ScrollView drag path Just Works. Coordinates
divided by dpi_scale so layout-side hit tests match. poll_events
drains its slice after returning (mirrors the SDL pattern).
- src/imports.zig now routes #import c { #source / #include } paths
through the same chain as #import (importing dir -> CWD -> stdlib
search paths). Lets library-owned C helpers like the JNI bridge
live in sx/library/vendors/ without forcing consumers to vendor a
copy. Existing CWD-relative consumer layouts (chess's vendors/...)
still resolve first, so no regression.
86/86 regression tests pass.
platform/android.sx: `sx_android_bootstrap(app)` now also reads the
ANativeActivity's `assetManager` (offset 64) and `internalDataPath`
(offset 32) into module globals so consumers can route file I/O
through the APK's bundled `assets/` tree.
target.zig (`createApk`): also zips the project's `./assets/`
directory into the APK alongside `lib/<arch>/`. Resolves relative
to the user's CWD at invoke time — matches the convention chess
uses (assets/ next to main.sx).
gles3.sx: scissor is currently a no-op on Android. The renderer's
ScrollView clip_push path feeds bounds that land outside the
framebuffer (clipping everything off-screen). With scissor disabled
the chess board + pieces render correctly. TODO recorded in the
file to fix the bounds path properly.
C imports (stb_image, stb_truetype) compiled via the embedded LLVM
clang library now resolve bionic headers on Android. main.zig auto-
fills target_config.sysroot with the NDK root (mirroring the iOS path
that auto-fills the iOS SDK path); c_import.zig derives the bionic
sysroot inside it and passes `--sysroot <ndk>/toolchains/llvm/prebuilt/<host>/sysroot`
to the embedded clang.
Android link branch in target.zig stops auto-appending entries from the
collected `#library` / `#framework` lists. Most `#library` directives
in the stdlib (`objc.sx`'s `objc :: #library "objc";`, frameworks set
by uikit.sx, etc.) describe Apple-specific intent that's nonsensical on
Android. Users opt into Android-side libs via `opts.add_link_flag(...)`
in build.sx — same shape as how the iOS branch already lists frameworks
in chess's configure_build.
Verified end-to-end: chess game compiles for Android, packages into a
debug-signed APK, installs and launches on Pixel 7 Pro. It crashes in
UIRenderer.init because raw GL calls run before EGL is up — same
architectural gap iOS bridges via the Metal GPU protocol. Next step
is a GLES3 GPU impl or a lazy-init in UIRenderer. 86/86 regression
tests + iOS-sim chess build clean.
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.
- `-F <dir>` CLI flag adds Apple framework search paths (parallel to `-L`).
- `TargetConfig.framework_paths` flows into the iOS link line (`-F<dir>`).
- iOS link adds `-Wl,-rpath,@executable_path/Frameworks` so embedded
frameworks resolve at runtime.
- `createBundle` now takes the framework list; for each one it locates
`<name>.framework` in the `-F` paths and `cp -R`s it into
`<bundle>.app/Frameworks/`.
- `c_import.compileCToObjects` forwards `-target`/`-isysroot` to clang so
`#c_import` works under cross-compile (was using host clang implicitly).
- iOS SDK is auto-discovered once at startup and shared by both the C
compile and the link paths.
- `SX_DEBUG_LINK=1` prints the resolved link argv.
- `library/modules/sdl3.sx`: drop `#library "SDL3"` — linking is now
per-target (build.sx handles `-lSDL3` on macOS, `-framework SDL3` on iOS).
- 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
