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 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.
