`#jni_call` collapses to a single surface — env is *always* implicit:
either picked up from the lexically-enclosing `#jni_env(env) { ... }`
block's Ref (cheap, register-resident, no TL touch) or from the
runtime's thread-local slot via `sx_jni_env_tl_get()` (one fn call
per dispatch). The explicit-env shape is gone — chess and the
existing tests migrate cleanly by wrapping their helper-fn bodies
in `#jni_env(env) { ... }`.
The TL slot lives outside the user's IR module so the LLVM ORC JIT
can load object files cleanly without `orc_rt` for TLS support:
library/vendors/sx_jni_runtime/sx_jni_env_tl.c:
static _Thread_local void *sx_jni_env_tl_slot;
void *sx_jni_env_tl_get(void) { return sx_jni_env_tl_slot; }
void sx_jni_env_tl_set(void *env) { sx_jni_env_tl_slot = env; }
Linkage:
- sx-the-compiler links the .c file via build.zig so the JIT
process-symbol generator resolves `sx_jni_env_tl_get`/`_set`.
- AOT targets get the same .c file auto-linked via the lowering
pass: when lower touches the TL externs, it sets
`needs_jni_env_tl_runtime`, and `Compilation.lowerToIR` appends a
synthetic `CImportInfo` to `lowering_extra_c_sources` that
`collectCImportSources` merges with user-written ones.
Lowering-side changes:
- `getJniEnvTlFids` lazily declares the two externs (parallel
to `getSelRegisterNameFid`) and flips `needs_jni_env_tl_runtime`.
- `#jni_env(env) { body }` emits save→set→body→restore via three
`call` ops to the externs; the inner body sees env via the
lexical-direct stack.
- `lowerJniCall` resolves env from `jni_env_stack` (top) or the TL
fallback. The explicit-env branch is gone.
- `jni_env_stack_base` tracks per-fn lexical scope so lazy-lowering
a callee doesn't accidentally see the caller's Ref (Refs are only
valid inside one fn's instruction stream).
Test migration (mechanical):
- ffi-jni-call-{01..09}: each helper fn wraps `#jni_call(...)`
bodies in `#jni_env(env) { ... }`. Returning values pass through
the block as an expression — `#jni_env` now also lowers in
expression position.
Verified:
- zig build test + tests/run_examples.sh: 130/130 green.
- tests/cross_compile.sh: 3/3 green.
- Chess APK rebuilt + reinstalled on Pixel. Board renders with
status-bar clearance + info panel intact; no crashes in logcat.
Safe-insets dispatch through `#jni_env` + lexical-direct now
fully exercised end-to-end on real hardware.
Two `#jni_call` sites with the same string-literal `(name, sig)` pair
now share a single `jclass` GlobalRef slot and a single `jmethodID`
slot, populated lazily on the first call to any matching site.
Non-literal sites keep the per-call `GetObjectClass` + `GetMethodID`
sequence from step 1.15.
Per-call-site lowering for literal sites:
%cached_mid = load ptr, @SX_JNI_MID_<key>
%is_cached = icmp ne ptr %cached_mid, null
br i1 %is_cached, cont, miss
miss:
%local_cls = GetObjectClass(env, target)
%global_cls = NewGlobalRef(env, local_cls) ; vtable slot 21
store ptr %global_cls, @SX_JNI_CLS_<key>
%fresh_mid = GetMethodID(env, global_cls, name, sig)
store ptr %fresh_mid, @SX_JNI_MID_<key>
br cont
cont:
%mid = phi ptr [%cached_mid, before], [%fresh_mid, miss]
call <Type>Method(env, target, %mid, args...)
Wiring:
- `JniMsgSend.cache_key: ?CacheKey` (new) carries `(name_str,
sig_str)` when both `name` and `sig` are string-literal AST nodes;
empty for non-literal call sites.
- `lower.zig` populates `cache_key` from the AST.
- `emit_llvm.zig` `getOrCreateJniSlots(name, sig)` returns the
`{cls_slot, mid_slot}` pair, creating and caching them on first
lookup. Key is `name\x00sig` so the separator can't collide with
any JNI identifier byte.
- `mangleJniKey` builds an LLVM-identifier suffix from the pair, used
in the `@SX_JNI_{CLS,MID}_<suffix>` global names.
IR snapshot at `tests/expected/ffi-jni-call-03-methodid-sharing.ir`
updated: two call sites against literal `("noop", "()V")` now share
`@SX_JNI_CLS_noop____V` and `@SX_JNI_MID_noop____V`. Pre-1.17 snapshot
had two independent `GetMethodID` calls; post-1.17 has one global
slot pair plus per-call lazy-init branches.
Note: an unrelated regression in `examples/ffi-objc-call-12-rect-u64-returns.sx`
exists in the working tree (parse error from an in-progress C-import
block) and is left untouched.
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.
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).
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.
