Rewrote 20 issue writeups to the extern/runtime-class vocabulary (#foreign→extern,
foreign_class_map→runtime_class_map, parseForeignClassDecl→parseRuntimeClassDecl,
findForeignMethodInChain→findRuntimeMethodInChain, dedupeForeignSymbol→
dedupeExternSymbol, is_foreign_c_api→is_extern_c_api, stale filename refs to the
renamed examples, foreign-class→runtime-class, bare foreign→extern). Renamed
issues/0043-…-foreign-class-…→…-runtime-class-….
PHASE 9 COMPLETE — 9.4 GATE PASSES: zero 'foreign' across src/library/examples/
issues/docs/editors/specs/readme/CLAUDE, excluding only the SQLite API constant
SQLITE_CONSTRAINT_FOREIGNKEY + vendored sqlite3.c/.h (upstream third-party).
Suite green (644 corpus / 443 unit, 0 failed).
Two genuine defects behind the 0128 filing (whose original repros were
both poisoned by binding getenv, which std already declares -> *u8):
1. Re-declaring a C symbol was silent first-wins: every call through
the later declaration was typed by the older signature. Foreign
registration now dedupes — equal signatures share one FuncId,
conflicting ones are diagnosed.
2. Foreign -> string / -> ?string returns read garbage: C returns one
char*, but the LLVM signature declared the fat {ptr,i64} (len =
register garbage), and ?string was mis-declared SRET (the hidden
out-pointer landed in the callee's first arg register). cstrRetKind
now classifies such returns, declares them as plain ptr (never
sret), and the call site synthesizes {ptr, strlen} via a
branch-guarded strlen (NULL -> {null,0} / optional null), wrapping
{string, i1} for ?string.
?[:0]u8 itself resolves fine (it is ?string); the spelling works in
return, param, local, and alias positions.
Regression: examples/1221 (plain + optional non-null + NULL paths) and
examples/1172 (conflict diagnostic); both FAIL pre-fix. The extern
dedupe collapses duplicate libc decls, so affected .ir snapshots were
regenerated. zig build test 426/426; run_examples 602/602;
distribution suite 21/21.
[:0]u8 aliases string (fat) and params already ABI-thin to char*, but
a foreign -> [:0]u8 return silently resolves to plain u8, and ?[:0]u8
never resolves at all (LLVM emission panic) even though ?string works.
Design contract recorded: ?[:0]u8 lowers to a nullable char* at the
boundary, length synthesized on the sx side; until then such returns
must be diagnosed, not mis-typed.
