16 fn/global examples across categories (0415/0602/0603/1024/1025/1605/1607-1609/
1611/1616/1619/1622/1628/1635/1636): bare '#foreign'→'extern'. All cls=0 (no class
forms). Marker'd ones (1605/1609/1611 + the rest) corpus-validated; the 3 unmarked
uikit importers (1607/1608/1616) verified byte-identical via 'sx ir' probes.
Empty snapshot diff; suite green (647 corpus / 444 unit, 0 failed).
LEFT comment-only/provenance #foreign (0716/0729 + issues/0030-extern-global +
extern-test files 1223-1231/1332/1348/1349/1426) and the keep-list (identity
ffi-foreign-* + foreign-asserting diagnostics 1172/1174/1219/1228/1620) for Phase 8.
13 JNI examples migrated (1410-1419/1423/1424/1425): import runtime classes
'#foreign #jni_class("X") {' → '#jni_class("X") extern {'. 1417 (all-runtimes)
also exercises #jni_interface/#objc_class/#objc_protocol/#swift_class/#swift_struct/
#swift_protocol — all take the postfix modifier (verified by probe), migrated via a
generalized '#foreign #<directive>("X") {' → '… extern {' rewrite. No 14xx snapshot
asserts on 'foreign'; empty snapshot diff, corpus-validated.
KEPT comment-only #foreign in 1426 (jni-extern-class test, no decls). Suite green
(647 corpus / 444 unit, 0 failed).
18 obj-c examples migrated (1308/1311-1317/1319/1320/1321/1341-1347): import
runtime classes '#foreign #objc_class("X") {' → '#objc_class("X") extern {'
(prefix→postfix) + fn/comment '#foreign'→'extern'. No 13xx snapshot asserts on
'foreign' text → all behavior-preserving; empty snapshot diff, corpus-validated.
Per the keep-list policy: KEPT identity-#foreign tests 1306/1318 (filename
ffi-*-foreign*); LEFT comment-only #foreign in the extern/export test files
1332/1348/1349 (no decls). Bare defined #objc_class examples (no #foreign) untouched
— not a purge target. Suite green (647 corpus / 444 unit, 0 failed).
12 plain-C examples that use #foreign incidentally (as FFI plumbing, output
unchanged): 1200/1206/1209-1215/1220/1221/1222. Blanket keyword swap; all fn/global
markers (no class forms in 12xx). Empty snapshot diff; corpus validates directly
(all marker'd). Suite green (647 corpus / 444 unit, 0 failed).
KEPT on #foreign (deferred to Phase 8 cutover): identity-#foreign feature tests
(filename ffi-foreign-*: 1205/1207/1216/1218/1219), the equivalence test 1228, and
the diagnostics that assert on #foreign source/message (1172/1174/1620). Comment-only
provenance prose (1223/1229/1230/1231) left intact per Decision-6-recommended.
Pure source rename across objc/objc_block/raylib/sdl3/wasm (~51 sites): fn-decl
markers (bare / 'objc' LIB ref) → 'extern …', and objc.sx's 2 import runtime
classes '#foreign #objc_class("X") {' → '#objc_class("X") extern {'. No bare
defined classes. Behavior-preserving. objc + objc_block validated directly by the
50 marked 13xx corpus examples (incl. import classes 1300/1301 + defined classes
1339/1349); raylib/ffi-sdl3/wasm (no marked importers on host) verified by
byte-identical 'sx ir' probes pre/post. Empty snapshot diff; suite green (647
corpus / 444 unit, 0 failed).
Pure source rename across 11 std modules (~60 sites): cli/core/fmt/fs/log/
net/kqueue/process/socket/thread/time/trace. All fn-decl markers — bare
'#foreign;', '#foreign libc;'/'#foreign tlib;' (LIB ref), and
'#foreign libc "csym";' (LIB+rename) → the same 'extern …' tail (extern carries
the identical [LIB] ["csym"] axis). Plus 2 stale comment mentions (fmt/fs).
No class forms in std. These modules ARE host-corpus-exercised, so the empty
snapshot diff is direct validation. Suite green (647 corpus / 444 unit, 0
failed).
Pure source rename across uikit/android/android_jni/sdl3 (~64 #foreign sites):
- 30 fn decls '… #foreign;' → '… extern;'
- 34 import runtime classes '#foreign #objc_class/#jni_class("X") {' →
'#objc_class/#jni_class("X") extern {' (prefix → postfix modifier)
- 4 defined Sx* obj-c classes '#objc_class("X") {' → '… export {'
Behavior-preserving (AST already unified post-Phase-5.0). Verified byte-identical
IR via 'sx ir' on the uikit importers 1610 + 1606 (which compile uikit incl. the
4 defined Sx* classes on host) and an sdl3 probe; android.sx (host-incompatible,
only compiles under OS==.android) verified by an identical 4-error dedup set (the
keyword-neutral 'foreign symbol already bound' message is unchanged). Empty
snapshot diff; suite green (647 corpus / 444 unit, 0 failed).
Pure source rename: all 97 'sqlite3_* ... #foreign sqlib "csym";' fn decls
→ 'extern sqlib "csym";' (+ the one stale header-comment reference). The
extern_lib axis references the 'sqlib' #import c unit identically to #foreign
sqlib, so IR/output is byte-identical. Empty snapshot diff; example 1624
(vendor-sqlite-module) stdout byte-unchanged. Suite green (647 corpus / 444
unit, 0 failed).
Phase 5.0 flipped the fn-decl and data-global #foreign parser paths onto the
same extern-named AST that postfix extern produces, so the A→B gate's fn/global
cases are now STRUCTURALLY identical (guaranteed by construction, not empirically
equal). Annotate the gate header to record this and keep it as a regression
tripwire against a future reader re-diverging the two spellings or a revert of
the flip. Add a fn-rename case (extern_name axis: c_abs -> "abs") to broaden
coverage beyond bare import. Test-only; suite green (647 corpus / 444 unit, 0
failed). PHASE 5.1 COMPLETE → PART B Phase 5 done; next Phase 6 (migrate stdlib).
The fn-body `#foreign [LIB] ["csym"]` marker now builds the SAME shape postfix
`extern` produces — extern_export = .extern_ + extern_lib/extern_name + an
empty-block body — instead of a `foreign_expr` body. With all four prereqs
landed (visibility, variadic, plain-free classification, lib-ref validation),
every downstream reader coalesces is_foreign with extern_export, so the IR and
runtime behavior are byte-identical (full corpus + the A->B gate stay green).
The surface keyword is no longer on the AST, so a `#foreign`-spelled decl now
yields `extern`-worded diagnostics — the single accepted churn (Decision 7):
example 1620's lib-ref error flips '#foreign library' -> 'extern library'.
Parser-surface diagnostics (conflict/expected-token) fire on the literal keyword
and are unaffected. c_import auto-synthesis still emits foreign_expr bodies (not
this step), so both shapes still coexist. Parser unit test updated to assert the
extern shape.
647 corpus / 444 unit, 0 failed. The const-with-type (dead) + runtime-class
(already coalesced) paths need no flip — Phase 5.0 parser routing is complete.
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.
checkForeignRefs now reads a library reference from either spelling — the
legacy #foreign body (foreign_expr.library_ref) or the new extern keyword
(extern_lib) — and validates both against the declared #library / #import c
units. The diagnostic names the surface keyword the user wrote (#foreign vs
extern), so example 1620 (#foreign) is byte-unchanged and example 1231
(extern) gets the parallel 'extern library ... not declared'. Greens 1231.
647 corpus / 444 unit, 0 failed.
An `extern LIB "csym"` ref must name a declared #library / #import c unit,
like its `#foreign LIB` twin (example 1620). Today checkForeignRefs reads
only foreign_expr.library_ref and skips the extern keyword's extern_lib, so
a bogus `extern nosuchunit "abs"` compiles silently (the symbol resolves
via the default image and runs). Expected pins the DESIRED compile-time
diagnostic; the next commit extends checkForeignRefs to green it. Fourth
extern/#foreign divergence and a prerequisite for the fn-decl migration.
647 corpus (1231 xfail), 444 unit.
isPlainFreeFn / isPlainFreeFnDecl excluded a #foreign body but classified
an empty-block extern fn as a plain free function, so existing extern fns
were wrongly counted in the bare-call ambiguity verdict (and eligible for
the out-of-line-slot / shadow-author pass). Both predicates now also
exclude extern_export == .extern_ (an external C symbol with no
sx-lowerable body, name-keyed first-wins dispatch like #foreign); export
keeps a real body and stays plain-free. Greens example 1230 — same-name
extern authors compile like their #foreign twins (0729).
646 corpus / 444 unit, 0 failed.
Two flat imports each declare `absval` via `extern libc "abs"` (the
`extern` twin of example 0729's `#foreign` form). Like its #foreign twin,
this must compile + run (prints 7), not error as an ambiguous bare-call
collision.
Today `isPlainFreeFn` / `isPlainFreeFnDecl` exclude a `#foreign` body but
classify an empty-block `extern` fn as a plain free function, so the two
extern authors ARE counted in the bare-call ambiguity verdict and the call
errors. A third extern/#foreign divergence (after visibility + variadic)
and a prerequisite for migrating the fn-decl `#foreign` path onto `extern`.
646 corpus (1230 xfail), 444 unit.
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).
Two gates were keyed on the `#foreign` (foreign_expr) body shape only:
- declareFunction: the is_variadic drop (decl.zig) — a variadic extern
kept its trailing slice param in the IR signature.
- packVariadicCallArgs: the call-site early-out (pack.zig) — extras were
slice-packed instead of passed through the C `...` slot.
Both now also fire for `extern_export == .extern_`, so a variadic
`extern` drops the trailing `..args: []T`, sets is_variadic, and passes
extras through the C ABI with default argument promotion — byte-identical
to its `#foreign` twin. Greens example 1229.
645 corpus / 444 unit, 0 failed.
A trailing `..args: []T` on an `extern` fn must map to the C `...` tail
like its `#foreign` twin (example 1218). Today the variadic handling in
both declareFunction (is_variadic drop) and packVariadicCallArgs
(call-site early-out) is gated on `#foreign` only, so a variadic
`extern` keeps the trailing slice param and slice-packs the extras —
garbage at the C ABI (probe: sum_ints(3,10,20,30) → 53316585, not 60).
Example 1229 pins the DESIRED correct output; the next commit extends
both gates to cover extern and greens it. Prerequisite for migrating the
fn-decl `#foreign` path onto `extern`.
645 corpus (1229 xfail), 444 unit.
- 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.
The non-transitive C-import visibility gate (`isVisible(.c_import_bare)`)
only recognised the legacy `#foreign` body shape; a bare `extern` fn
(empty-block body + extern_export == .extern_) escaped via the
`body != foreign_expr -> return true` arm and was caught only by the
general isNameVisible gate, yielding the generic 'not visible' wording
instead of the C-specific 'C function not visible; add #import' one.
Now both lib-less spellings route to visibleOverEdges, and a library-
bound `extern LIB` (like a library-bound `#foreign LIB`) stays
unconditionally visible. This makes a future fn-decl `#foreign`->`extern`
migration byte-identical at this gate. Greens example 1228.
644 corpus / 444 unit, 0 failed.
Cross-module example (main → b → c) referencing c's lib-less C imports
transitively. The non-transitive C-import gate (lower/decl.zig
c_import_bare) must police the legacy `#foreign` form and the new
`extern` keyword IDENTICALLY — same 'C function not visible' diagnostic,
not the generic top-level-name wording. Today the extern twin escapes the
c_import_bare gate (body is an empty block, not foreign_expr) and is only
caught by the general isNameVisible gate, yielding the generic message.
Expected snapshot pins the DESIRED equivalent wording; the next commit
aligns the gate to green it. Prerequisite for migrating the fn-decl
`#foreign` path onto `extern`.
443/444 corpus (1228 xfail), 444 unit.
Part B begins: `#foreign` becomes an alias for `extern`. First of the four
`#foreign` parser paths to migrate — the data-global form
(`name : T #foreign [lib] ["csym"];`). It now builds the SAME extern-named
VarDecl (`is_extern`/`extern_lib`/`extern_name`) that the postfix `extern`
global path already produces, instead of `is_foreign`/`foreign_lib`/`foreign_name`.
Behavior-preserving: lowering coalesces the two forms identically — the symbol
name is `extern_name orelse foreign_name orelse name` (decl.zig:1119), and both
`is_foreign` and `is_extern` feed the same `.is_extern` IR flag + early-return
(decl.zig:1127,1141). The A->B gate already proved fn/global/class lower to
byte-identical IR, so the corpus locks this with zero snapshot churn.
Suite green: 10/10 steps, 444/444 unit, 643 corpus, 0 failed.
The fn-decl, const-with-type, and runtime-class `#foreign` paths still build the
legacy AST; they migrate next (the fn path needs the deferred visibility-gate +
variadic alignment first).
Eliminates the recurring -Dupdate-goldens churn: these 5 were 0-byte
outliers while 484 other empty goldens use the writeGolden-produced
1-byte "\n" form. The corpus runner trims trailing newlines on both
sides during verify, so both forms passed — but regen always rewrote
them to 1-byte. Conforming them makes -Dupdate-goldens idempotent.
The define path now honors the optional `export … "csym"` symbol-name
override (gap iii). declareFunction's rename branch fires for `export` too:
the extern stub is declared under the C name and the sx→C mapping recorded
in foreign_name_map. lazyLowerFunction then resolves the stub by that C
name (via foreign_name_map) so the body promotes into the C-named function
— emitting `define @triple_c` instead of `@sx_triple`. sx-side call sites
to the sx name resolve through the same map (verified: 5*5 prints 25).
example/1227 greens: the companion C calls `triple_c` and prints
call_triple(7) = 22. Bare export (1226) is unaffected (no rename → sx
name). Suite green (638 corpus / 443 unit). Phase 2 (`export`) complete.
example/1227 exposes the sx fn `sx_triple` to C under the symbol `triple_c`
via `export "triple_c"`; the companion C calls `triple_c` by that name.
RED: the define path emits the fn under its sx name (`sx_triple`) and
ignores the parsed `extern_name`, so the C reference to `triple_c` is
undefined at AOT link. The next commit consumes the rename on the define
path (gap iii) and greens it.
