Filed issues/0138: `@const` (address-of a `::` comptime constant) lowers
to `inttoptr (i64 <value> to ptr)` — segfaults on deref, invalid store for
asm `-> @const`. Root cause in src/ir/lower/expr.zig .address_of (not asm).
Marked CHECKPOINT-ASM Next step BLOCKED on 0138 for the output-to-const
rejection item.
An asm result can be STORED through a place (a local / struct field) instead of
returned; the place output does not join the result tuple.
- parser.zig: `-> @place` parses `@place` as an ordinary address-of expression
→ an out_place operand (the in-function form; reuses the existing `@` prefix).
- inst.zig: AsmOperand gains out_ty (the output slot's value type) so emit can
build the combined return struct without re-deriving from Inst.ty.
- lower/expr.zig: out_place operand = the lowered @place address, out_ty = the
pointee. Read-write (`+`) and indirect-memory (`*`) constraints rejected loudly
(not yet implemented) rather than miscompiled.
- ops.zig emitInlineAsm: the LLVM return type is built from ALL outputs
(out_value + out_place); after the call, out_place slots are stored through
their address and out_value slots rebuild the sx result. Fast path when there
are no place outputs (the struct return IS the result — pure-value asm IR
unchanged).
Verified: write-to-local (42), struct field, mixed value+place (v=10 b=20), `+`
rejected. Locked with 1649-platform-asm-place-output (mixed, runs on aarch64).
zig build test green (657 corpus, 446 unit).
A top-level `asm { "tmpl", };` block (template only) lowers to LLVM `module asm`;
a lib-less `extern` declaration calls into the symbols it defines (the import
direction reuses the existing C-FFI extern path — no new surface).
- ast.zig: asm_global node (AsmGlobal { template }).
- parser.zig: parseAsmGlobal, dispatched from parseTopLevel on kw_asm — rejects
`volatile` and any operands/clobbers (template only). The in-function asm
expression form stays in parsePrimary.
- module.zig: Module.global_asm list; lower/decl.zig captures each template in
lowerMainAndComptime (the real top-level pass — lowerDecls is dead for
top-level); emit_llvm.zig emit() appends each via LLVMAppendModuleInlineAsm in
source order.
- the new node forced asm_global arms in sema.zig (analyzeNode +
findNodeAtOffset) and semantic_diagnostics.zig (checkBindingNames).
Verified end-to-end: an aarch64 `_my_add` global routine, called via `extern`,
returns 42 — AOT only (the ORC JIT doesn't link module-asm symbols; global-asm
symbols live in the final linked binary). Locked with 1648-platform-asm-global
({ "aot": true, "target": "macos" } → AOT build+run on aarch64, ir-only else).
zig build test green (656 corpus, 446 unit).
Replaces the N>1 "Phase E" bail with a shared asmResultType helper (lowering +
inferType) that derives the result type from the out_value operands: 0→void,
1→T, N→a named tuple (fields named via the §II.5 effective-name rule).
Key realization: toLLVMType(tuple) already produces a literal struct {T1,…,Tn} —
exactly what LLVM's multi-output inline asm returns — so emit needs NO change.
Building the op with a tuple result type makes the asm call return the struct,
which IS sx's tuple value (destructured by the normal tuple_get path).
inferType's .asm_expr arm now also delegates to asmResultType (single owner), so
`return asm`, `x := asm`, and `q, r := asm` all agree on the type.
Verified end-to-end on aarch64: split(0x1234)→(lo=52,hi=18), a udiv/msub
divmod→(3,2). IR: `call { i64, i64 } asm "divq ${4}",
"={rax},={rdx},{rax},{rdx},r,~{cc}"(…)` → extractvalue → tuple.
1640 → the x86_64 multi-output IR lock (ir-only); 1647 → a multi-output example
that runs on aarch64.
zig build test green (655 corpus, 446 unit).
lowerAsmExpr stops bailing and builds the inline_asm op: resolves each operand's
effective name (§II.5 — explicit [name] else the {reg} pin), interns
template/constraints/clobbers, lowers input Refs, derives the result TypeId
(0→void, 1→T). Adds the last deferred validation (every %[name] must name an
operand). Multi-output (N>1) bails with a named "Phase E" diagnostic.
emitInlineAsm (backend/llvm/ops.zig) ports Zig's airAssembly: assembles the LLVM
constraint string (outputs → inputs → ~{clobber}, ',' → '|'), rewrites the
template (%[name]→${N}, %%→%, $→$$, %=→${:uid}), then LLVMGetInlineAsm +
LLVMBuildCall2 (AT&T dialect). Dispatch wired in emit_llvm.zig (replacing the C.0
@panic tripwire).
inferType gains an .asm_expr arm (expr_typer.zig) so a bare `x := asm {…-> T}`
binding types correctly — without it the binding inferred .unresolved and
silently produced 0.
llvm_shim.c: LLVMInitializeNativeAsmParser() — the JIT must assemble inline asm
at run time.
Verified end-to-end on the aarch64 host: `mov`/`add` with register-class inputs
and a value output run (exit 42/99), `nop volatile` runs (exit 0). IR is
textbook: `call i64 asm "add ${0},${1},${2}", "=r,r,r"(…)`.
Locked with 1645 (aarch64 add, runs; ir-only on non-aarch64) + 1646 (:= binding).
Updated 1640 (now Phase-E bail) + 1642 (now runs).
zig build test green (654 corpus, 446 unit).
Adds the `inline_asm: InlineAsm` opcode to the IR Op union (inst.zig): interned
template + operand list (role/name/constraint/operand) + interned clobber names
+ has_side_effects; the result rides on Inst.ty (void / scalar / tuple).
The new variant forces coverage in the exhaustive Op switches:
- interp.zig: loud bailDetail — inline asm is never comptime-evaluable.
- print.zig: an IR-dump arm.
- emit_llvm.zig: a @panic TRIPWIRE — emit lands in Phase D, and until then
lowerAsmExpr still bails, so no inline_asm op is ever created. Reaching emit
would mean lowering switched over before emit was ready; crash loudly rather
than miscompile.
No behavior change: lowering still bails, the op is constructed only in the new
`inline_asm op shape` unit test (inst.test.zig).
zig build test green (652 corpus, 446 unit).
Extends lowerAsmExpr with a pinnedRegister(constraint) helper and two §II.5
operand-naming checks, in the compile path before the codegen bail:
- reject the echo form `[eax] "={eax}"` — a label identical to the register its
own constraint pins is redundant (the operand is already auto-named after the
register); the useful form is a label that differs (`[quot] "={rax}"`);
- reject duplicate operand names (ambiguous %[name] / result field).
Locked with 1643-platform-asm-echo-name and 1644-platform-asm-duplicate-name.
zig build test green (652 corpus, 445 unit).
Restructures the .asm_expr lowering arm into lowerAsmExpr, which validates the
asm shape with specific named diagnostics BEFORE the not-yet-implemented codegen
bail, so the user sees the real problem first. Two checklist items enforced:
- template must be a compile-time-known string ("..." or #string), not a
runtime expression;
- an asm with no value outputs must be `volatile` (else its effects could be
deleted) — mirrors Zig's rule.
Valid shapes still bail with the "codegen not yet implemented" message. Result-
type derivation + the operand auto-naming rule stay deferred to Phase C, where a
real IR op makes the result type observable/testable.
Locked with 1641-platform-asm-missing-volatile (the volatile error) and
1642-platform-asm-nop-volatile (no-output + volatile accepted → codegen bail).
zig build test green (650 corpus, 445 unit).
`asm volatile? { "tmpl", [name]? "constraint" (-> Type | = expr), …,
clobbers(.…) }` now parses into a flat-operand AsmExpr/AsmOperand (ast.zig +
parser.zig parseAsmExpr, dispatched from parsePrimary on .kw_asm). `volatile`
and `clobbers` are recognized contextually (not reserved). `-> @place`
write-through is rejected with a clear "Phase 2" parse error.
Codegen is not implemented yet (IR op + LLVM emit are Phases C–E), so lowering
bails LOUD + named via an explicit .asm_expr arm in lower/expr.zig (not the
generic unknown_expr else) — emitPlaceholder makes hasErrors() abort the build
on the message.
The new asm_expr tag forced (and got) arms in three exhaustive Node.Data
switches: sema.zig analyzeNode + findNodeAtOffset, semantic_diagnostics.zig
checkBindingNames — each recurses into template + operand payloads.
Design: adopted the operand auto-naming rule (design §II.5) — name auto-derived
from a {reg} pin, explicit [name] only when it differs or for register-class
operands, echo form rejected. Typing-stage rule; parser stores name: ?[]const u8.
Locked with examples/1640-platform-asm-parse.sx (multi-output divmod: named
operands, register pins, clobbers — parses then bails, called from main).
Also files issue 0137 (pre-existing, orthogonal: `sx run` with no `main`
segfaults via an unguarded JIT entry lookup in target.zig — not an asm bug).
zig build test green (648 corpus, 445 unit).
`asm` now lexes as a dedicated `kw_asm` keyword (Token.Tag + keyword map entry).
`volatile` and `clobbers` stay out of the global keyword table — they are
recognized contextually only inside an `asm { … }` body (PLAN-ASM Deviation 4).
- token.zig: kw_asm tag + `.{ "asm", .kw_asm }` map entry.
- lsp/server.zig: classifyToken exhaustive switch gained the .kw_asm arm
(the new enum value forced coverage — intended tripwire).
- lexer.test.zig (new, wired into root.zig barrel): locks `asm`->kw_asm and
`volatile`/`clobbers`->identifier.
Lock commit (behavior-locking passing test). zig build test green (445 unit).
CLAUDE.md §Testing + §Test-layout now describe the optional `<name>.build` JSON
config (aot + target keys, ir-only arch-gating, unknown-key-is-error) and list
it among the `expected/` files, replacing the stale standalone `.aot` marker
prose. Closes Phase 0 (corpus target-gating); next is Phase A (kw_asm keyword).
When a `.build` target doesn't match the host, the runner can't execute the
example here, so it verifies via `sx ir --target` only: asserts exit + the `.ir`
snapshot (stdout) + diagnostics (stderr), never `.stdout`. An `.ir` snapshot is
REQUIRED in ir-only mode — its absence is a loud failure, never a silent pass.
- corpus_run.test.zig: ir_only flag (target set & !hostMatchesTarget); first
dispatch arm runs `sx ir`, sets act_exit/act_err/act_ir; skip stdout in both
update and verify modes; require ir_raw.
- lock fixture 1639-platform-target-cross (asm-free main, target x86_64-linux,
checked-in .ir). Verified: corrupt .ir => IR mismatch; delete .ir => require
failure.
Test-infra only; no compiler code. zig build test green (647 corpus, 444 unit).
Two post-stream follow-ups flagged in CHECKPOINT-EXTERN-EXPORT.md, plus a
reproducible vscode-extension packaging setup:
- parser: drop the vestigial `RuntimeClassPrefix.is_extern` field and
`parseRuntimeClassDecl`'s `is_extern` param. Always false since the
`#foreign` token was deleted; the postfix `extern`/`export` keyword is the
sole reference-vs-define decider. No behavior change (644 corpus / 442 unit).
- vscode grammar: highlight `extern`/`export` as `storage.modifier.sx`.
- vscode packaging: declare `@vscode/vsce` as a devDep + add `package` /
`vscode:prepublish` scripts so the vsix rebuilds reproducibly (was an
ambient tool). Add repository/homepage/bugs (Gitea), icon (swipelab logo,
256x256), galleryBanner, README with cover banner. Rebuilt the vsix.
Plain-free classification + extern lib-ref validation closed (the 3rd and
4th extern/#foreign divergences). All four fn-path prereqs now done. The
fn-decl #foreign->extern flip is scoped: IR zero-churn, only example 1620's
lib-ref wording churns. Records Decision 7 (interim diagnostic wording) as
the one gate before executing the flip.
Next step is the fn-decl #foreign body-marker migration onto extern
(behavior-preserving single refactor commit; lowering + both prereq
gates already coalesce is_foreign with extern_export).
- Mark deferred prereq (b) visibility-gate equivalence CLOSED (1228).
- Record const-with-type as a dead path (deferred per user) and the
runtime-class prefix as already-coalesced (no Phase 5.0 change).
- Next step is the fn-path variadic prerequisite.
Parser: a 'kw_extern' branch in the var-decl-with-type-annotation path
(beside #foreign) parses 'name : type extern [LIB] ["csym"];' into
VarDecl.is_extern/extern_lib/extern_name; the trailing diagnostic now
lists 'extern'. Lowering: registerTopLevelGlobal uses
extern_name orelse foreign_name orelse name for the C symbol and sets
is_extern = is_foreign or is_extern; globalInitValue returns null (no
initializer) for extern globals too.
examples/1225 green: '__stdinp : *void extern;' lowers to
'@__stdinp = external global ptr'; @__stdinp reads non-null. Suite
green (636 corpus / 443 unit).
Phase 1 done: extern functions (bare + rename) and data globals (bare +
rename) all work, behavior-equivalent to the matching #foreign form.
export (Phase 2), aggregates (Phase 3), docs + A->B gate (Phase 4)
remain. green commit.
Add examples/1225-ffi-extern-global.sx — '__stdinp : *void extern;'
references libSystem's stdin pointer via the bare 'extern' modifier on
a typed var decl (the extern-named counterpart of the #foreign global
in examples/1205). Hand-authored snapshot expects the success output.
RED: 1225 is the sole corpus failure (636 ran, 1 failed) — parse error,
'extern' after a type annotation is not yet accepted in the var-decl
path. Phase 1.2d parses it and lowers the extern global.
xfail commit per the cadence rule.
parseFnDecl parses the optional [LIB] ["csym"] tail after the
extern/export keyword into FnDecl.extern_lib/extern_name (mirrors
'#foreign LIB "csym"'). declareFunction unifies the symbol-name
override: rename_c_name = foreign_expr.c_name (for #foreign) OR
fd.extern_name (for extern) -> declare under the C name and map sx->C
in foreign_name_map; the dedupe guard now covers extern too.
examples/1224 green: 'c_abs :: (n) -> i32 extern "abs";' resolves
c_abs to libc abs -> c_abs(-42) = 42. 1223 (bare extern) unregressed.
Suite green (635 corpus / 443 unit).
extern_lib is parsed + stored but not a linking driver — like
'#foreign libc', it references a lib; the #library decl + build flags
remain the separate linking axis (decision 4). green commit.
Add examples/1224-ffi-extern-fn-rename.sx — 'c_abs :: (n) -> i32
extern "abs";' binds C's abs via the optional symbol-name override.
Hand-authored expected captures the success output (c_abs(-42) = 42).
RED: 1224 is the sole corpus failure (635 ran, 1 failed) — parse error,
the '"abs"' string after 'extern' is not yet accepted. Phase 1.2b
parses the optional [LIB] ["csym"] tail and consumes the rename.
xfail commit per the cadence rule.
Route a bare 'extern' fn declare-only, exactly like a lib-less #foreign
import. Six edits in decl.zig, each mirroring an existing foreign_expr
guard so the empty-block placeholder body is never lowered:
1. funcWantsImplicitCtx: suppress the implicit __sx_ctx for .extern_
2. declareFunction: add is_extern_decl
3. ...and include it in the C-ABI calling-convention promotion
4. lazyLowerFunction: .extern_ -> declareFunction (declare-only)
5. lowerFunction: .extern_ in the declare-only guard
6. lowerFunctionBodyInto: never promote/lower an extern stub
examples/1223 now green: 'extern' abs lowers to 'declare i32 @abs(i32)'
(external linkage, C ABI, no ctx param) and the call resolves against
the default-linked libc -> abs(-7)=7, abs(42)=42. The 1.0b hand-authored
snapshot matched byte-exact (no regen). Suite green (634 corpus / 443
unit). green commit (makes the 1.0b xfail pass; adds no new test).
Add examples/1223-ffi-extern-fn.sx — binds libc 'abs' via bare 'extern'
(sx name = C symbol, no rename). Hand-authored expected/ captures the
SUCCESS output (abs(-7)=7 / abs(42)=42, exit 0).
RED: 1223 is the sole corpus failure (634 ran, 1 failed) — it parses
then errors at sema ('body produces no value') because lowering does
not yet route extern fns through declareExtern. Phase 1.1 wires the
lowering and turns this green.
xfail commit per the cadence rule (no commit both adds a test and makes
it pass).
parseFnDecl now calls parseOptionalExternExport() after the callconv
slot and stores the modifier on FnDecl.extern_export. For 'extern' the
body is ';' (an empty-block placeholder — the modifier carries the
linkage, no *_expr node, per the naming constraint). Both fn-decl
lookahead predicates (isFunctionDef, hasFnBodyAfterArrow) now treat
kw_extern/kw_export as fn-body markers beside kw_callconv, so
'(...) -> R extern;' is recognized as a fn def rather than a fn-type
const.
Per user feedback, decision 4 ("library separate") is REVISED: extern
carries an optional LIB + "csym" axis mirroring '#foreign LIB "csym"',
so it is a true #foreign superset (Gate A->B requirement — the Part B
migration of 466 #foreign uses across 6 libs must preserve each
symbol's library). Added FnDecl.extern_lib/extern_name and
VarDecl.extern_lib (beside is_extern/extern_name).
All unconsumed by lowering: extern parses, but a fn still errors at
sema (body produces no value). Suite green (443 unit / 633 corpus).
lock commit.
Add ast.ExternExportModifier { none, extern_, export_ } beside
CallingConvention; FnDecl.extern_export and VarDecl.is_extern/extern_name
fields (all defaulting to absent); and Parser.parseOptionalExternExport()
mirroring parseOptionalCallConv.
None of this is consumed by a decl path yet — no user-facing behavior
change, corpus diff empty. Two inline parser unit tests pin the helper's
keyword mapping and the field defaults. Phase 1.0 wires the helper into
the fn-decl path. lock commit.
Lex 'extern' and 'export' as keywords beside 'callconv': new token.Tag
variants + keywords StaticStringMap entries + LSP semantic-token keyword
classification. Adds a 'lex linkage keywords' unit test.
Tokens only — parser/AST plumbing and lowering land in later phases.
Corpus sweep confirmed no .sx identifier collides with the new reserved
words. lock commit per the cadence rule.
Two new workstreams:
- ASM: inline assembly — asm { "tmpl", "=r" -> T, "r" = expr, clobbers(.…) },
multi-return tuples; lowers via the existing llvm_api.c (no shim).
- FFI-linkage: add extern/export postfix keywords, migrate every #foreign onto
them, then purge 'foreign' from the tree (end-state invariant).
Drop current/ from .gitignore so plans + checkpoints are tracked normally
(the dir was ignored; only checkpoints had been force-added). Includes
docs/inline-asm-design.md. specs.md change left uncommitted.
