Per CLAUDE.md IMPASSIBLE RULES. Attempted Phase 3.2 C4 migration of
the UIKit chrome cluster in `library/modules/platform/uikit.sx`
(UIScreen / UIWindow / UIViewController / UITextField / UIView)
surfaced a real compiler bug: when a function body contains
`recv.method(...)` calls against an `#objc_class` receiver AND that
body is reached via `lazyLowerFunction` invoked from another
`inline if OS == ...` branch, the method dispatch fails with
"unresolved 'methodName'".
Specifically: `uikit_scene_will_connect_ios` (the iOS-sim crashing
case) contains `UIWindow.alloc().initWithWindowScene(scene)` etc.
The same calls compile cleanly in isolated probes — only the lazy-
lower-via-inline-if entry chain reproduces the bug. macOS target
builds fine throughout; ios-sim trips it.
C1/C2/C3 (commits 1ea9cda / 17775b2 / 2a7c8e0) happen to land cleanly
because the methods they migrate are reached eagerly (or are niladic
so the dispatch path doesn't hit the failing branch). C4 + C5 stay
blocked pending issue-0043's fix in a separate session.
Issue filed at `issues/0043-lazy-lower-loses-foreign-class-method-dispatch.md`
with the reproduction, stack trace, and investigation prompt
pointing at `lower.zig:1057` (`lazyLowerFunction`) and
`lower.zig:5290` (the field-access foreign-class dispatch chain).
FFI checkpoint updated to mark C4+C5 as BLOCKED on 0043.
The in-progress C4 working-tree changes were reverted; tree is at
the C3 commit `2a7c8e0` and chess on macOS/iOS-sim/Android builds
cleanly.
The session-long set of changes that lay the groundwork for the
Jai-literal implicit-Context-parameter refactor. Lots of accumulated
work; the new arrival is the implicit-ctx foundation (steps 1+2 of
the plan in current/CHECKPOINT-MEM.md):
Step 1 — `CAllocator :: struct {}` stateless allocator in
library/modules/allocators.sx, delegating directly to
libc_malloc/libc_free. `ConstantValue` in src/ir/inst.zig gains a
`func_ref: FuncId` leaf so nested aggregates can carry function
pointers (the inline Allocator value's fn-ptr fields). Switch
sites updated in emit_llvm.zig, print.zig, interp.zig.
Step 2 — `emitDefaultContextGlobal` in src/ir/lower.zig synthesises
a static `__sx_default_context` global with a nested-aggregate
init_val pointing at the CAllocator → Allocator thunks. The
second-pass `initVtableGlobals` in emit_llvm.zig is generalised
to handle `.aggregate` init_vals (re-emits after func_map is
populated so func_ref leaves resolve to real symbols).
Also folded in from earlier work this session:
- Phase 1.1: `xx value` heap-copy in `buildProtocolValue` routes
through `context.allocator` via the new `allocViaContext` helper.
- interp.zig: `marshalForeignArg` double-offset bug fixed —
`heapSlice` already adds `hp.offset` to the slice ptr, so the
extra `+ hp.offset` was scribbling memcpy/memset into adjacent
heap state, corrupting `heap.items[0]`. Symptom: `build_format`
at comptime produced zero bytes, all `print` calls failed.
- Lazy lowering: `lazyLowerFunction` now declares foreign-body
functions as extern stubs in the local (comptime) module so
cross-module foreign calls resolve.
- Allocator API: all stdlib allocators on one-line `init() -> *T`
(CAllocator/GPA: libc-backed; Arena/TrackingAllocator: parent-
backed; BufAlloc: embeds state at head of user buffer).
- issues 0038 (transitive #import), 0039 (chess + stdlib migration
fallout), 0040 (generic struct method dot-dispatch), 0041
(pointer types as type-arg), 0042 (alias name resolution) — all
fixed; regression tests in examples/.
- Diagnostic: `emitError` now embeds the lowering's
`current_source_file` and enclosing function in the literal
message; SX_TRACE_UNRESOLVED=1 dumps a Zig stack trace at the
emit site so misattributed spans can't hide where the failure
is.
- tools/verify-step.sh (all-platforms gate) and tools/scratch.sh
(interp/codegen parity tester) added.
Test suite: 152 example tests pass; chess builds + screenshots on
macOS / iOS sim / Android.
