Third step toward writable globals. The C cgen and its selfhost
mirror now:
- emit DATAW <name>(SB),"<8 LE bytes>" for every top-level `let`
whose type lands in the scalar set (i8..i64/u8..u64/bool/rune/
int/uint/uintptr/ptr; floats and multi-word types deferred);
- drop the "no writable .data" silent-drop guard at the N_IDENT
store path, replacing it with a RIP-relative MOVQ for `=` and
a load→combine→store sequence for the compound ops; and
- route `&name` through LEAQ name(SB) instead of dropping it.
Type aliases resolve via aliaslookup so `type counter = i32; let c:
counter = 0;` still emits a DATAW slot. Non-literal initialisers
silently skip, which surfaces as a clean undefined-symbol error if
the binding is ever referenced.
The selfhost mirror lands in the same commit because test 990
diffs the C cgen against wwdump_ww -c on err.ww (which has
top-level `let nerrors: i32 = 0; ... nerrors += 1;`). Any drift
between the two cgens makes 990 fail. Bootstrap stays at a fixed
point: ww2 == ww3 == ww4 byte-identical.
Cascades the four enum kinds through every signature and local that
holds one of their values, then removes the type_assignable /
unify_arith relaxation that previously let bare i32 mix with the
named enum types.
Signature updates:
- kwlookup() now returns `tkind` (not i32); tokname() takes `tkind`
- accepttok / expecttok / bprec / isassignop take `tkind`
- parsearglist's closekind is `tkind`
- newtype / prim take `tykind`; scopedefine takes `skind`
- newnode / nkname take `nkind`
Struct fields:
- tok.kind is `tkind`; parser.curkind is `tkind`
- node.kind is `nkind`; node.op is `tkind`
- tinfo.kind is `tykind`; sym.skind is `skind`
Locals holding kinds across lex/parse/check/cgen are now typed with
their enum, including sentinel patterns like `let lkind: nkind =
nkind.N_NONE; if (...) lkind = tn.kind;`.
The selfhost cgen had a load-width bug exposed by this: fieldsize()
fell back to 8 bytes for any TNAME that wasn't a struct or primitive.
For a tkind-typed field that gave `MOVQ (BX), AX` instead of `MOVL`,
diverging from the C cgen on tok.kind / parser.curkind / etc. Two
fixes:
- fieldsize now consults the enum registry and returns the storage
type's size (4 for `enum i32`)
- collectenums runs before collectstructs in cgfile so the registry
is populated when registerstruct asks for field sizes
All 22 tests stay green; 990/993/995 byte-identity probes pass with
the strict typing in place.
`type tkind = enum i32 { TK_NONE = 0, TK_EOF = 1, ... TK_LAST = 86 }`
replaces the 87-line `def TK_*: i32 = N` cluster in lib/ww/lex/tok.ww.
Numeric values explicit so 990_selfhost's byte-diff against the C-side
`Tkind` enum still passes.
All ~270 reference sites in lib/ww and selfhost/cmd/{wcc,wwdump}
sed-renamed `TK_X` → `tkind.TK_X`. Struct fields (`tok.kind`,
`parser.curkind`) intentionally kept as `i32` — making them `tkind`
shifted some byte-positions in the cgen output and broke 990/993/995
byte-identity probes without an obvious win.
To make the rename non-cascading on every signature, type_assignable
and unify_arith in cmd/wcc/check+type relax to allow enum ↔ int
mixing when storage matches (a `tkind` value flows into an `i32`
slot and vice versa, no explicit cast). This deviates from Hare's
strict enum semantics; doc'd as an explicit pragmatic relaxation
for the compiler's internal enum-shaped kinds. External user code
can still get the type-safety benefit if they declare their
parameters with the enum type.
combined.ww files regenerated by ww build.
Driver-side concatenation flattens module names, but enum member
lookup keyed off the exact lhs ident — so `whence.CUR` worked while
`os.whence.CUR` fell through to w6l with `undefined main.whence`.
C side: fold TY_ENUM members in the post-cexpr cascade too, not
just the early SK_TYPE shortcut. The recursive cexpr lands the
inner N_DOT(os, whence) on the named enum type; the outer access
then folds normally.
Selfhost: cgdot now treats `N_IDENT.MEMBER` and `N_DOT.MEMBER` the
same way, keying off the leaf name. enumlookup strips a trailing
`.`-prefix from the lookup key.
Adds e2e test 700: `use os; os.whence.CUR as i32 == 1`.
w6c_ww now compiles enum end-to-end and emits byte-identical
asm to the C w6c on the new 994 corpus case (`type mode = enum u8
{ R, W, RW = R | W }; main() { return (mode.RW): i32 }`). Mechanism
mirrors the C side:
- collectenums walks every `type X = enum {...}` at file scope and
pre-resolves each member's u64 value (auto-increment from prior,
sibling-ref folding for `RDWR = READ | WRITE`).
- cgdot recognises `EnumName.MEMBER` before the local lookup and
emits MOVQ $value, AX directly.
- cgtypeassert short-circuits when either side is enum: cgexpr on
the LHS lands the value in AX with the right integer width; no
tag/unwrap.
main.combined.ww (wwdump/ + w6c/) regenerated by ww build.
C cgen has carried defer for a while (defers[] global + reverse
walk on every return). Selfhost cgen now mirrors:
- cgen struct: deferbuf (**node, LIFO stack) + defertop counter.
- cgstmt N_DEFER: push n.lhs.
- cgreturn: rundefers() at entry — same as the C cgen pattern.
- cgfn fall-through return: rundefers() before zero-AX+RET.
DEFER_MAX = 16 matches C cgen.
Two new e2e rows: defer with an explicit `return acc;` (321 mod 256
= 65), and defer firing on an implicit void-fn fall-through (87).
Both rows verified via the wwstage cgen too.
Defer's semantics: queued exprs fire LIFO before the return expr
is evaluated, so a return that reads memory mutated by a deferred
call sees the post-defer state. Matches C cgen and Hare.
`match (e) { ... }` can now sit in expression position, with each
arm using `yield expr;` to produce the match's value:
let v = match (r) {
case let n: i32 => yield n + 1;
case let s: str => yield s.len: i32 + 100;
};
TK_YIELD keyword + N_YIELD AST node, both appended at the tail of
their enums to keep prior numeric values byte-stable for the
wwdump-diff gates.
Checker: cexpr for N_MATCH walks each arm's body looking for the
first N_YIELD; the match's type is the unified yield type (or
ty_void if no yield, preserving the statement-form semantics).
Mismatched arm yields are flagged.
Cgen: a yield-target stack (separate from the loop break stack)
holds each enclosing match's end label. N_YIELD evaluates its
expression into AX (and BX for str) and JMPs to the topmost entry.
cgmatch pushes its end label on entry and pops on exit.
Selfhost mirror: lib/ww/lex/tok.ww kwtab+name, lib/ww/ast.ww
N_YIELD def+print, lib/ww/parse/stmt.ww yield-stmt; selfhost cgen
adds a yieldbuf to the cgen struct and a cgyield helper. Verified
end-to-end: a yield-using program compiled via the wwstage cgen
matches the C-cgen build's exit code.
Plan 9-style w-prefix on the per-arch tools, disambiguating from the
real Plan 9 6c/6a/6l in ref/plan9front/:
cmd/wwc/ → cmd/wcc/ libwwc.a → libwcc.a
cmd/6{c,a,l} → cmd/w6{c,a,l} binary names too
test/wwc/ → test/wcc/ 6 test files w/ w6 prefix
selfhost/cmd mirror in lockstep
bootstrap/amd64/{w6c,w6a,w6l} snapshot binaries (gitignored)
WW_6{C,A,L} → WW_W6{C,A,L} env-var overrides
Plan 9 source-tree refs ("Plan 9 6c shape", ref/plan9front/, etc.)
preserved. Hare-style driver, both C and ww sides:
ww test [path] discover *_test.ww in a directory module, run
each; single-file mode for `ww test foo.ww`
Module-by-name `ww build foo` resolves to foo.ww or foo/foo.ww
via search path (cwd : -I dirs : $WW_LIB)
Default-to-cwd `ww build` / `ww test` build the cwd module
Run pass-through `ww run path arg1 arg2` reaches the program
lib/os: getcwd (79) and getdents64 (217) syscalls power `.` resolution
and directory enumeration on the ww side.
Makefile: wwstage tool deps now include lib/os/os.ww (+ lib/strconv
for wwdump_ww) so lib/* edits force their rebuild instead of leaving
stale binaries — surfaced when test 995 first failed against a stale
w6c_ww built before the lib/os additions.
Test 993 byte-identical parity gate (C-side ww vs ww-side ww_ww on a
build corpus) stays green; all 19 tests pass.
