78e304f552
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).
64 lines
3.8 KiB
Markdown
64 lines
3.8 KiB
Markdown
# sx `extern`/`export` + `#foreign` retirement — Checkpoint (FFI-linkage stream)
|
|
|
|
Companion to `current/PLAN-EXTERN-EXPORT.md` — one merged plan: **Part A** adds
|
|
`extern`/`export`, **Part B** migrates `#foreign` and purges `foreign`. Update after
|
|
every commit, one step at a time per the cadence rule.
|
|
|
|
## Last completed step
|
|
**Phase 1.0b** (xfail — example half of 1.0) — added `examples/1223-ffi-extern-fn.sx`
|
|
(extern-binds libc `abs` via bare `extern`; sx name = C symbol, no rename) +
|
|
hand-authored `expected/` capturing the SUCCESS output (`abs(-7) = 7` / `abs(42) =
|
|
42`, exit 0). **RED**: 1223 is the only corpus failure (634 ran, 1 failed) — it parses
|
|
then errors at sema (`body produces no value`) because lowering doesn't route extern
|
|
yet. Phase 1.1 turns it green. (Prior: 1.0a (lock, green) wired fn-path extern
|
|
parsing — `parseFnDecl` → `parseOptionalExternExport()` → `FnDecl.extern_export`,
|
|
`;` body = empty-block placeholder; both lookahead predicates accept
|
|
`kw_extern`/`kw_export`; per user feedback added `FnDecl.extern_lib`/`extern_name` +
|
|
`VarDecl.extern_lib`, decision 4 REVISED.)
|
|
|
|
## Current state
|
|
Syntax: bare `extern`/`export`, postfix after `callconv(.c)`, `extern ⇒ callconv(.c)`.
|
|
**Decision 4 revised** (user 2026-06-14): `extern` carries an optional `LIB`+`"csym"`
|
|
axis (`extern_lib`/`extern_name`) like `#foreign`; the `#library` decl + build-flag
|
|
linking stays separate. Touch-points: token `token.zig:45,282`; parser
|
|
`1950,3669,316,425,1305`; lowering `decl.zig:1123,387,2110,2382,2514`; IR/emit already
|
|
capable (no codegen change). Part B `foreign` footprint to purge: 643 lines / ~57
|
|
identifiers in `src/` + 28 doc lines. End-state invariant: **zero `foreign`** (Phase
|
|
9.4 gate). **Done**: tokens (0.0) + AST/parser plumbing (0.1) + fn-path extern parsing
|
|
+ lib/name fields (1.0a), all unconsumed. Lowering not yet wired.
|
|
|
|
## Next step
|
|
**Phase 1.1** (green, turns 1223 green) — in `decl.zig`, when
|
|
`fn_decl.extern_export == .extern_`, route the fn through `declareExtern` (`is_extern`,
|
|
`.external` linkage, `callconv(.c)`, no implicit ctx — anchors `decl.zig:1123,387,
|
|
2110,2113`) instead of lowering the empty-block placeholder body. Treat the bare
|
|
`extern` (no `extern_lib`/`extern_name` yet) like a lib-less `#foreign` import — the
|
|
sx name IS the C symbol, resolves against the default-linked libc. Run, then
|
|
`-Dupdate-goldens` to finalize 1223's snapshot byte-exact; review diff. Then **1.2**
|
|
(green): consume `extern LIB "csym"` rename (`extern_lib`/`extern_name`) + extern-global
|
|
`g : T extern;` (`parser.zig:425`). Stop at end of Phase 1.
|
|
|
|
## Open decisions
|
|
Part A ratified (bare / postfix / `⇒ callconv(.c)` / lib-separate). Part B (confirm
|
|
before Phase 9): runtime-class rename target — `Runtime*Class*` (recommended);
|
|
historical carve-out — keep `issues/*.md` provenance, gate the live tree only.
|
|
|
|
## Log
|
|
- (init) Plan written; FFI-linkage stream opened.
|
|
- (merge) Folded FOREIGN-MIGRATION in as Part B; deleted the split plan + checkpoint.
|
|
- (0.0) Added `kw_extern`/`kw_export` tokens + keyword-map entries + LSP keyword
|
|
classification + `lex linkage keywords` test. Suite green; no identifier collisions
|
|
in the corpus. `lock` commit.
|
|
- (0.1) Added `ast.ExternExportModifier` + `FnDecl.extern_export` +
|
|
`VarDecl.is_extern`/`extern_name` + `parseOptionalExternExport()` (unconsumed) + 2
|
|
parser unit tests. Suite green (443/633). `lock` commit.
|
|
- (1.0a) Wired fn-path extern parsing (`parseFnDecl` + both lookahead predicates) +
|
|
added `FnDecl.extern_lib`/`extern_name` + `VarDecl.extern_lib` per user feedback
|
|
(decision 4 revised: extern carries an optional lib axis). Unconsumed by lowering.
|
|
Suite green (443/633). `lock` commit.
|
|
- (1.0b) Added `examples/1223-ffi-extern-fn.sx` + hand-authored success snapshots.
|
|
RED (634 ran, 1 failed — sema `body produces no value`). `xfail` commit; 1.1 greens it.
|
|
|
|
## Known issues
|
|
None yet.
|