Files
ww/selfhost/cmd/wcc/check.ww
Hojun-Cho ba044e206d wcc: route deref-call N_CALL to fn-VALUE fallback (#181)
Pre-fix the wwstage checker bailed asserttyped on the N_CALL whose
callee was N_UN TK_STAR over a *fn — selfhost/cmd/wcc/check.ww
exprtype's N_CALL arm only resolved IDENT/DOT-named callees and
early-returned nil for any other shape, leaving e.type_ unstamped
so the post-checker invariant fired. cstage worked because cexpr
recurses on the callee — TK_STAR's unop arm returns t->sub which
IS the TY_FN, no name path needed.

Fix: replace the `if (nm.len == 0) return nil` early-bail with
`if (nm.len > 0) { name-lookup }`, so non-named callees fall
through to the existing fn-VALUE fallback below (peel TPTR /
dealias to TFN / stamp the result type). Mirrors harec
check_autodereference at ref/harec/src/check.c:1566. cgen post
-#180+#185 already lowers the deref-call correctly, so lifting
the asserttyped bail is silent-SIGSEGV-safe per drew + ken.

Combined.ww regenerated for selfhost/cmd/{w6c,wwdump}/main
.combined.ww per #110 freshness gate.

Probe: test/wcc/766_star_fn_deref_call.c, 5 rows table-driven —
minimal / branched-callee / alias-chain / fn-with-args / fn
-tuple-return. Gate flip from 765: every row now gates BOTH
stages — cstage runtime, wwstage runtime, AND cs.s == ww.s byte
-id. This is the runtime coverage 765 deferred plus the symmetry
gate that proves both stages emit identical asm for the deref
-call shape. Closes the full c-cluster (#180 + #185 + #181 all 3
commits working together end-to-end).
2026-05-28 20:01:14 +09:00

3806 lines
144 KiB
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// selfhost/cmd/wcc/check.ww — minimal port of cmd/wcc/check.c.
//
// Status: name-resolution + primitive-type seeding only. Full type
// inference, conversion rules, tagged-union dispatch typing, return-
// type checking, etc. all live in cmd/wcc/check.c (937 lines) and
// will land here in subsequent commits.
//
// What this version does:
// 1. Creates a top scope and seeds it with primitive type names so
// `i32`, `str`, `*u8` etc. resolve.
// 2. Walks the file's top-level decls (use/def/type/fn/let) and
// installs Sym entries for each.
// 3. Recursively walks fn bodies; for every nkind.N_IDENT used as an
// expression or as a type name, looks it up and counts the
// resolved vs. unresolved.
// 4. Returns a summary the caller (wwdump -r) prints; the test
// asserts unresolved == 0 on every selfhost fixture, which is
// the floor signal that the frontend can name-resolve real ww.
package wcc;
import os;
import tok;
import strconv;
type checker = struct {
tc: *tctx,
top: *scope,
cur: *scope,
nresolved: i32,
nunresolved: i32,
errs: i32,
verbose: i32, // when non-zero, log each unresolved name
fnret: *node, // enclosing fn's return type AST (for `?`)
curmod: str, // importing-module bareword for the decl
// currently being walked; "" for primary
// compilation unit. Drives same-module
// preference in bare-leaf lookups.
file: *node, // N_FILE root; used by checkmoduleshadow
// to consult the declaring source's own
// `use` directives.
};
// seedprimitives — install the built-in type names so `i32`, `str`,
// etc. can be looked up like ordinary symbols.
fn seedprimitives(c: *checker) void = {
scopedefine(c.top, "void", skind.SK_TYPE, c.tc.tyvoid, nil);
scopedefine(c.top, "bool", skind.SK_TYPE, c.tc.tybool, nil);
scopedefine(c.top, "rune", skind.SK_TYPE, c.tc.tyrune, nil);
scopedefine(c.top, "i8", skind.SK_TYPE, c.tc.tyi8, nil);
scopedefine(c.top, "i16", skind.SK_TYPE, c.tc.tyi16, nil);
scopedefine(c.top, "i32", skind.SK_TYPE, c.tc.tyi32, nil);
scopedefine(c.top, "i64", skind.SK_TYPE, c.tc.tyi64, nil);
scopedefine(c.top, "u8", skind.SK_TYPE, c.tc.tyu8, nil);
scopedefine(c.top, "u16", skind.SK_TYPE, c.tc.tyu16, nil);
scopedefine(c.top, "u32", skind.SK_TYPE, c.tc.tyu32, nil);
scopedefine(c.top, "u64", skind.SK_TYPE, c.tc.tyu64, nil);
scopedefine(c.top, "int", skind.SK_TYPE, c.tc.tyint, nil);
scopedefine(c.top, "uint", skind.SK_TYPE, c.tc.tyuint, nil);
scopedefine(c.top, "uintptr", skind.SK_TYPE, c.tc.tyuintptr, nil);
scopedefine(c.top, "f32", skind.SK_TYPE, c.tc.tyf32, nil);
scopedefine(c.top, "f64", skind.SK_TYPE, c.tc.tyf64, nil);
scopedefine(c.top, "str", skind.SK_TYPE, c.tc.tystr, nil);
scopedefine(c.top, "never", skind.SK_TYPE, c.tc.tynever, nil);
// #29: predeclare `type nomem = !void;` so user code needn't
// declare it locally. Synthesize an nkind.N_TYPEDECL whose lhs is
// nkind.N_TBANG{nkind.N_TNAME("void")} so varianterr and other
// iserror-aware paths treat `nomem` identically to a user-written
// alias. Mirrors cmd/wcc/check.c lookup_builtin returning
// ty_nomem (NAMED, under=ty_void, iserror=1). Note: cgen owns a
// separate alias chain — see collectaliases in cgen.ww for the
// companion seed.
let empty: str;
let tnvoid: *node = newnode(nkind.N_TNAME, empty, 0, 0);
tnvoid.str = "void";
let bang: *node = newnode(nkind.N_TBANG, empty, 0, 0);
bang.lhs = tnvoid;
let nomemdecl: *node = newnode(nkind.N_TYPEDECL, empty, 0, 0);
nomemdecl.str = "nomem";
nomemdecl.lhs = bang;
scopedefine(c.top, "nomem", skind.SK_TYPE, nil, nomemdecl);
// `nil`, `true`, `false` are keywords — handled at the lex/parser
// level, no symbol needed.
// `len`, `alloc`, `free`, `append` are pseudo-builtins; scopedefine
// them so their use sites resolve. The actual semantics live in cgen.
scopedefine(c.top, "len", skind.SK_FN, nil, nil);
scopedefine(c.top, "alloc", skind.SK_FN, nil, nil);
scopedefine(c.top, "free", skind.SK_FN, nil, nil);
scopedefine(c.top, "append", skind.SK_FN, nil, nil);
// #42: typed builtins folded to integer literals at check time —
// `size(T)` / `align(T)` (arg is a type-expression planted by the
// parser at lib/ww/parse/expr.ww:254-267) and `offset(e.f)` (arg is
// an N_DOT). exprtype intercepts these and rewrites the N_CALL to
// N_INTLIT so cgen never sees an unresolved size/align/offset symbol.
// Mirrors cmd/wcc/check.c:907-955.
scopedefine(c.top, "size", skind.SK_FN, nil, nil);
scopedefine(c.top, "align", skind.SK_FN, nil, nil);
scopedefine(c.top, "offset", skind.SK_FN, nil, nil);
};
// declmod — module-tag stamp for a top-level decl.
//
// The driver concatenates imported sources before the primary file and
// emits `// MODULE: foo` directives the lexer pins onto each decl's
// `module` field. We treat a decl as "imported" iff its module
// directive matches some `use IDENT;` bareword in this compilation
// unit. Primary-file decls return "" so they coexist (mod="") with
// imported decls of the same leaf name in scopelookupinmodule.
fn declmod(file: *node, d: *node) str = {
let empty: str;
if (d == nil) { return empty; };
if (d.nmod.len == 0) { return empty; };
if (file == nil) { return empty; };
let u: *node = file.list;
for (u != nil) {
if (u.kind == nkind.N_USE) {
if (streq(u.str, d.nmod)) { return d.nmod; };
};
u = u.next;
};
return empty;
};
// srcimports — does the source file that contributed decl-module
// `modtag` carry `use <name>;`? Mirrors cstage's src_imports —
// `modtag.len == 0` means primary, matching declmod's empty-str
// return for primary-source decls.
fn srcimports(file: *node, modtag: str, name: str) bool = {
if (file == nil) { return false; };
if (name.len == 0) { return false; };
let u: *node = file.list;
for (u != nil) {
if (u.kind == nkind.N_USE) {
// Skip self-imports: lib/fmt/fmttest.ww carries
// `use fmt;` while its module tag is also "fmt".
// That directive doesn't introduce a foreign
// module bareword and lib/fmt's own
// `fn bsprintf(fmt: str, ...)` is not a shadow.
if (u.nmod.len > 0) {
if (streq(u.nmod, u.str)) {
u = u.next;
continue;
};
};
let um: str = declmod(file, u);
let m: bool = false;
if (modtag.len == 0) {
if (um.len == 0) { m = true; };
} else { if (streq(um, modtag)) { m = true; }; };
if (m) {
if (streq(u.str, name)) { return true; };
};
};
u = u.next;
};
return false;
};
// checkmoduleshadow — enforce "value names and module names are
// disjoint" at nested-scope binds. Mirrors cstage check_module_shadow
// (cmd/wcc/check.c). Fires for fn params / lets / forrange iters /
// mcase bindings whose name matches an in-scope `use foo;` import
// declared in the same source file. Top-level decls are exempt
// (their same-leaf-as-module pattern is the intentional coexistence
// shape — `use fnmatch; fn fnmatch(...)` etc.).
fn checkmoduleshadow(c: *checker, name: str, kindstr: str) void = {
if (name.len == 0) { return; };
if (c.cur == c.top) { return; };
let seen: bool = false;
let s: *scope = c.cur;
for (s != nil) {
let r: *sym = scopelookuplocal(s, name);
if (r != nil) {
if (r.skind == skind.SK_USE) {
seen = true;
s = nil;
};
};
if (s != nil) { s = s.parent; };
};
if (!seen) { return; };
if (!srcimports(c.file, c.curmod, name)) { return; };
os.write(2, kindstr.ptr, kindstr.len: u64);
os.write(2, " '".ptr, 2u64);
os.write(2, name.ptr, name.len: u64);
os.write(2, "' shadows imported module '".ptr, 27u64);
os.write(2, name.ptr, name.len: u64);
os.write(2, "'\n".ptr, 2u64);
c.errs += 1;
};
// installdecl — install the top-level decl's name into the top scope.
// We don't compute its type yet (that's the resolve pass) — just bind
// the name so forward references resolve.
//
// Architectural note: wwstage uses COEXISTENCE rather than the cstage
// promote-SK_USE-in-place approach in cmd/wcc/check.c. SK_USE and any
// same-leaf SK_TYPE/SK_FN/SK_DEF/SK_VAR live as separate entries in
// the same scope-bucket, distinguished by `sym.mod`. This avoids the
// cstage use_alias FLAG (a field on the sym, which would grow its size
// and risk the wwstage cgen amalloc-undersize trap, rob-pike) — but the
// flag's RESOLUTION job still has to be done. When the colliding decl's
// package equals the importing unit's curmod (the `package fnmatch;` /
// `package random;` self-import: random.random, fnmatch.fnmatch), the
// mod-preferring scopelookupprefer returns the same-leaf SK_FN/SK_TYPE,
// not the coexisting SK_USE, so a dot-lhs `mod.x` would miss the
// module-qualified arm and the call nil-stamps (#6a-D). The dot-lhs
// resolvers in exprtype's N_CALL and N_DOT arms re-resolve through
// scopelookupuselocal (lib/ww/sym.ww) to the SK_USE that coexists in the
// landed scope — the coexistence-equivalent of cstage's use_alias bit.
// Cite: project memory module_type_name_collision (cstage fix
// 2026-05-13). #11 (wwstage checkfile pass) revisits the dup-decl errors
// below when wwstage grows a real check pass on the cgen path.
// TODO(#11): cstage check.c errors on duplicate top-level type/def/fn
// (see cmd/wcc/check.c L1800/L1839/L1860 "duplicate <kind>") and on
// duplicate top-level let (cmd/wcc/check.c L1880, "duplicate let %s")
// once #32 lands. Wwstage's installdecl just drops the second insert
// silently. Add `if (s == nil) err(...)` here once #11 wires checkfile
// into w6c_ww. Silent-accept matches the deferred-check design — see
// test/wcc/708 and test/wcc/696 for the same cstage-only neg-case
// precedent.
fn installdecl(c: *checker, file: *node, d: *node) void = {
if (d == nil) { return; };
let k: nkind = d.kind;
let nm: str = d.str;
let mod: str = declmod(file, d);
if (k == nkind.N_USE) { scopedefine(c.top, nm, skind.SK_USE, nil, d); return; };
if (k == nkind.N_DEF) { scopedefineinmodule(c.top, nm, mod, skind.SK_DEF, nil, d); return; };
if (k == nkind.N_TYPEDECL) { scopedefineinmodule(c.top, nm, mod, skind.SK_TYPE, nil, d); return; };
if (k == nkind.N_FNDECL) { scopedefineinmodule(c.top, nm, mod, skind.SK_FN, nil, d); return; };
if (k == nkind.N_LET) { scopedefineinmodule(c.top, nm, mod, skind.SK_VAR, nil, d); return; };
};
// stamptuplebinds — distribute a tuple's per-element types onto a
// destructure binding chain, walked in lockstep with the resolved
// N_TTUPLE element chain (each `elems` link carries its element type on
// .lhs). Mirror of harec's create_unpack_bindings
// (ref/harec/src/check.c:1354-1419), which harec shares between
// let-unpack (check_expr_binding) and the for-each loop header
// (ref/harec/src/check.c:2308-2317) — the one shape behind ww's
// `let (a,b) = f()`, `for (let (a,b) .. s)`, and the ww-extension
// multi-assign `a, _ = f()`.
//
// `define` (the binding contexts: let-unpack + for-range) installs each
// named binder as a fresh SK_VAR and back-fills its declared type onto
// .lhs so use sites resolve through the N_IDENT exprtype path. Multi-
// assign targets are pre-declared lvalues, so it passes false: .lhs is
// left untouched (an N_INDEX/N_DOT target carries a live operand there)
// and only the type_ stamp fires on the still-untyped slots.
//
// Each binder/target node's own type_ is stamped from its element type so
// the asserttyped gate sees a typed node. This covers the discard `_` (an
// empty-str N_IDENT with no decl to read a type back from): harec drops
// `_` yet still advances the tuple slot, so that slot's element type is
// the honest type to stamp — `_` is UNBOUND, not UNTYPED.
fn stamptuplebinds(c: *checker, binds: *node, elems: *node,
define: bool, what: str) void = {
let b: *node = binds;
let pt: *node = elems;
for (b != nil) {
let et: *node = nil;
if (pt != nil) { et = pt.lhs; };
if (define) {
if (b.lhs == nil) { b.lhs = et; };
let bnm: str = b.str;
if (bnm.len > 0) {
checkmoduleshadow(c, bnm, what);
scopedefine(c.cur, bnm, skind.SK_VAR, nil, b);
};
};
if (b.type_ == nil) {
let src: *node = b.lhs;
if (src == nil) { src = et; };
if (src != nil) {
let ti: *tinfo = tinfofornode(c, src);
if (ti != nil) { b.type_ = ti: *void; };
};
};
b = b.next;
if (pt != nil) { pt = pt.next; };
};
};
// resolvewalk — recursive AST walk that, for every nkind.N_IDENT and
// nkind.N_TNAME seen, looks up the name and bumps the resolved/unresolved
// counters. Local lets are installed in the current scope as soon as
// their init/type expressions have been walked (forward use of a let
// before its declaration would resolve to nothing — same semantics as
// the C checker's collect-then-resolve flow within a function).
// Also runs the typed checks (match exhaustiveness, ? subset) in
// the same pass — they need the same scope state.
fn resolvewalk(c: *checker, n: *node) void = {
if (n == nil) { return; };
let k: nkind = n.kind;
// Typed checks fire on the way down so the scrutinee/operand
// is examined before the arm bodies install new bindings.
if (k == nkind.N_MATCH) { checkmatchexhaust(c, n); };
if (k == nkind.N_TRYPROP) { checktryprop(c, n); };
if (k == nkind.N_TYPETEST) { checkisas(c, n); };
if (k == nkind.N_TYPEASSERT) { checkisas(c, n); };
if (k == nkind.N_LET) { checkletassign(c, n); };
if (k == nkind.N_RETURN) { checkretassign(c, n); };
// `use IDENT;` — name is a module label, not a free ident.
if (k == nkind.N_USE) { return; };
if (k == nkind.N_IDENT) {
let nm: str = n.str;
if (nm.len > 0) {
let s: *sym = scopelookupprefer(c.cur, c.curmod, nm);
if (s == nil) {
c.nunresolved += 1;
if (c.verbose != 0) {
os.write(2, " unresolved id: ".ptr, 17u64);
os.write(2, nm.ptr, nm.len: u64);
os.write(2, "\n".ptr, 1u64);
};
} else { c.nresolved += 1; };
};
};
if (k == nkind.N_TNAME) {
let nm: str = n.str;
if (nm.len > 0) {
let s: *sym = scopelookupprefer(c.cur, c.curmod, nm);
// `pkg.Type` — strip the last dot prefix and look up
// the leaf with a mod filter so same-leaf-name types
// from different imports (`bufio.stream` vs
// `io.stream`) disambiguate to the right one.
// Mirrors cmd/wcc/check.c resolve_typename.
if (s == nil) {
let dot: i32 = nm.len - 1;
for (dot >= 0) {
if (nm[dot] == 46u8) { break; };
dot -= 1;
};
if (dot > 0) {
let head: str;
head.ptr = nm.ptr;
head.len = dot;
let m: *sym = scopelookup(c.cur, head);
if (m != nil) {
let leaf: str;
leaf.ptr = nm.ptr + (dot + 1): u64;
leaf.len = nm.len - (dot + 1);
s = scopelookupinmodule(c.cur, head, leaf);
};
};
};
if (s == nil) {
c.nunresolved += 1;
if (c.verbose != 0) {
os.write(2, " unresolved tname: ".ptr, 20u64);
os.write(2, nm.ptr, nm.len: u64);
os.write(2, "\n".ptr, 1u64);
};
} else { c.nresolved += 1; };
};
};
// `for (let x .. slice) body` / `for (let (a, b) .. slice) body` —
// each binding name becomes a fresh local. Walk the slice expr first
// so its idents resolve before the bindings shadow anything, then
// install bindings and walk the body/else.
//
// TODO(#11): cstage check.c (post-#32) errors `binding '%s'
// redeclared in same scope` when the tuple-pattern lists the same
// name twice (`for (let (a, a) .. xs)`). Wwstage's resolvewalk has
// no per-block scope (see resolvefnbody's docstring) and is used
// only by wwdump_ww as a diagnostic, so silent-accept here avoids
// false-positives on legal cross-block shadow until #11 adds the
// scoping infrastructure.
if (k == nkind.N_FORRANGE) {
if (n.lhs != nil) { resolvewalk(c, n.lhs); };
if (n.list != nil) {
// Tuple destructure `for (let (a,b) .. xs)`: peel the
// iterable's element type and distribute its tuple
// element types onto the binders, the same lockstep walk
// harec runs for the for-each header
// (ref/harec/src/check.c:2308-2317 → create_unpack_bindings).
let elems: *node = nil;
let it: *node = exprtype(c, n.lhs, nil);
if (it != nil) {
let et: *node = nil;
if (it.kind == nkind.N_TSLICE) { et = it.lhs; };
if (it.kind == nkind.N_TARRAY) { et = it.lhs; };
if (et != nil) { if (et.kind == nkind.N_TTUPLE) {
elems = et.list;
}; };
};
stamptuplebinds(c, n.list, elems, true, "binding");
} else {
let bnm: str = n.str;
if (bnm.len > 0) {
checkmoduleshadow(c, bnm, "binding");
scopedefine(c.cur, bnm, skind.SK_VAR, nil, n);
};
};
if (n.body != nil) { resolvewalk(c, n.body); };
if (n.els != nil) { resolvewalk(c, n.els); };
return;
};
// `match (e) { case let v: T => stmt; ... }` — the binding `v`
// is declared by the case arm and visible inside its body. Push a
// fresh scope so `case let e: str` doesn't collide with an outer
// `let e: *T` (scopedefine drops same-scope dupes silently and
// would leave references to `e` resolving to the outer type).
// Mirrors cmd/wcc/check.c's newscope/saved-restore around cstmt.
if (k == nkind.N_MCASE) {
if (n.lhs != nil) { resolvewalk(c, n.lhs); };
let outer: *scope = c.cur;
c.cur = newscope(outer);
let nm: str = n.str;
if (nm.len > 0) {
checkmoduleshadow(c, nm, "binding");
scopedefine(c.cur, nm, skind.SK_VAR, nil, n);
};
if (n.body != nil) { resolvewalk(c, n.body); };
c.cur = outer;
return;
};
// #53: lexical block. Push a child scope so locals introduced by
// inner-block lets (and the `let` install at the tail of this fn) go
// out of scope at block exit. Without this, a deeply nested
// `let i: u64 = 0u64;` survived to shadow a same-named outer
// `let i: i32 = 1;` for the whole fn body, and exprtype handed
// stale primitive types to checkletassign — silent miscompile
// becomes a false-positive on the next driver (`wwdump_ww -r`
// flagged the u64→i32 pair in selfhost/cmd/ww/enumeratedir).
// Mirrors cstage cstmt N_BLOCK at cmd/wcc/check.c:1559-1566.
if (k == nkind.N_BLOCK) {
let outer: *scope = c.cur;
c.cur = newscope(outer);
let m: *node = n.list;
for (m != nil) {
resolvewalk(c, m);
m = m.next;
};
c.cur = outer;
return;
};
// `let (a, b) = call();` / `let a, b = call();` — destructure
// bindings. #121 (Package B, A-narrow): distribute the callee's
// tuple return-type element types onto the un-annotated bindings so
// later references stamp n.type_, matching cgen's structural binding-
// type classifier (cgmlet's rettupleof→localadd path). This closes
// the unstamped-float-destructure gap that the exprfloatkind collapse
// (commit 2's bridge) needs: without it a `let (f,i)=mk()` f64 binding
// reads stamp nil → would disagree with the structural f64.
//
// #6a-A: backfill off ANY call rhs, not just a bare N_IDENT callee, so
// a module-qualified `let (res, ov) = checked.addi64(a, b)` (N_DOT
// callee) stamps its bindings too. This is now a SINGLE path: just call
// exprtype(rhs) and consume the resolved N_TTUPLE — no callee resolution
// here. Harec's create_unpack_bindings does the same: ZERO callee
// resolution, it walks an already-typed tuple result (ref/harec/src/
// check.c:1354-1419). The module-qualified resolution that makes this
// correct for an N_DOT callee lives at the ROOT, in exprtype's N_CALL
// arm (the SK_USE-gated scopelookupinmodule there), so the binding just
// consumes. A D-class module whose leaf collides with a type/fn name
// resolves to nil/wrong-kind at the exprtype root (the SK_USE gate
// fails) → no N_TTUPLE → those destructures stay unstamped, a separate
// nominal-collision fold (#6a-D), not this one. Annotated bindings keep
// their own type. Mirrors the N_FORRANGE binding-install shape above;
// the bindings would otherwise install (unstamped) via the generic
// N_LET walk, so this early return must register them itself.
if (k == nkind.N_MLET) {
if (n.rhs != nil) { resolvewalk(c, n.rhs); };
let pt: *node = nil;
if (n.rhs != nil) { if (n.rhs.kind == nkind.N_CALL) {
// `rt` would shadow the imported lib/rt module
// (checkmoduleshadow errors); `rty` avoids it.
let rty: *node = exprtype(c, n.rhs, nil);
if (rty != nil) { if (rty.kind == nkind.N_TTUPLE) {
pt = rty.list;
}; };
}; };
stamptuplebinds(c, n.list, pt, true, "let");
return;
};
// `a, _ = call();` — tuple multi-assign (a retained ww extension over
// Hare; harec has no statement-position unpack-assign). Targets are
// pre-declared lvalues, resolved by the per-target resolvewalk below
// before the distribution; stamptuplebinds(define=false) only stamps
// still-nil slots, which is exactly the discard `_` (no decl, so the
// N_IDENT exprtype path leaves it untyped). Distribution mirrors the
// N_MLET/N_FORRANGE binders; see stamptuplebinds.
if (k == nkind.N_MASSIGN) {
if (n.rhs != nil) { resolvewalk(c, n.rhs); };
let pt: *node = nil;
if (n.rhs != nil) { if (n.rhs.kind == nkind.N_CALL) {
let rty: *node = exprtype(c, n.rhs, nil);
if (rty != nil) { if (rty.kind == nkind.N_TTUPLE) {
pt = rty.list;
}; };
}; };
let l: *node = n.list;
for (l != nil) { resolvewalk(c, l); l = l.next; };
stamptuplebinds(c, n.list, pt, false, "");
return;
};
if (k == nkind.N_DOT) {
// Walk only the base; the .field name is a member, not a
// free identifier.
if (n.lhs != nil) { resolvewalk(c, n.lhs); };
// A.6.0: branch returns early; stamp here so the post-walk
// dispatch below sees N_DOT covered. exprtype N_DOT arm is
// added in A.6.1; for now this is a no-op nil return.
let _t: *node = exprtype(c, n, nil);
return;
};
if (k == nkind.N_FIELD) {
if (n.lhs != nil) { resolvewalk(c, n.lhs); };
return;
};
if (k == nkind.N_TFIELD) {
if (n.lhs != nil) { resolvewalk(c, n.lhs); };
return;
};
// Walk children (mirroring ast.ww's printer descent order).
if (n.attr != nil) { resolvewalk(c, n.attr); };
if (n.lhs != nil) { resolvewalk(c, n.lhs); };
if (n.rhs != nil) { resolvewalk(c, n.rhs); };
if (n.cond != nil) { resolvewalk(c, n.cond); };
if (n.body != nil) { resolvewalk(c, n.body); };
if (n.els != nil) { resolvewalk(c, n.els); };
if (n.list != nil) {
let m: *node = n.list;
for (m != nil) {
resolvewalk(c, m);
m = m.next;
};
};
// #61 audit §1.8 — A.2 population: stamp tinfo onto type-expression
// nodes once their children have been walked (sub-element TNAMEs
// are now in scope so resolvealias inside tinfofornode can follow
// user-defined aliases). Cgen's slotsize fast-path reads off
// n.type_; uncovered shapes fall through to the cstage-mirror
// walker until the next sub-commit graduates them.
if (k == nkind.N_TNAME || k == nkind.N_TPTR ||
k == nkind.N_TSLICE || k == nkind.N_TCHAN ||
k == nkind.N_TBANG || k == nkind.N_TARRAY ||
k == nkind.N_TFN || k == nkind.N_TSTRUCT ||
k == nkind.N_TTUPLE || k == nkind.N_TTAGGED ||
k == nkind.N_TENUM) {
if (n.type_ == nil) {
let ti: *tinfo = tinfofornode(c, n);
if (ti != nil) { n.type_ = ti: *void; };
};
};
if (k == nkind.N_TENUM) { stampenumvals(c, n); };
// #42's size/align/offset fold trigger lived here pre-A.6.0; the
// A.6.0 end-of-fn general dispatch (below) now fires exprtype on
// every N_CALL — same context-free coverage, one dispatch site.
// After walking children: a local `let X: T = init;` registers
// `X` so subsequent statements can resolve it. Top-level lets
// are installed in installdecl, so this duplicate install at
// the file scope just no-ops (scopedefine returns nil on dup).
//
// Cross-block `let a; { let a; };` no longer trips dup-silence
// since #53 added N_BLOCK push/pop above — the inner `a` lands in
// the inner block's scope. Same-scope dup `let a=1; let a=2;`
// still silent-accepts here; promoting that to an error stays
// queued behind #11 (test/wcc/708 + test/wcc/696 are the cstage-
// only neg-case precedent).
if (k == nkind.N_LET) {
let nm: str = n.str;
if (nm.len > 0) {
checkmoduleshadow(c, nm, "let");
scopedefine(c.cur, nm, skind.SK_VAR, nil, n);
};
};
// #104 fold-2: narrow a bare f32-context float literal AFTER the
// child walk above — the post-order exprtype dispatch (below) re-
// stamps a bare N_FLOATLIT back to untyped_float, so coercing earlier
// (e.g. in checkletassign) would be undone. Placed here, the f32
// stamp on n.rhs / n.lhs sticks; cgen's fold-1 narrow then fires. let
// / return only — see coercefloatlit's docstring for the rule-10 scope
// (the cstage twin coerces in clet / cstmt N_RETURN). c.fnret is set
// by resolvefnbody for the enclosing fn, mirroring checkretassign.
if (k == nkind.N_LET) { coercefloatlit(c, n.rhs, n.lhs); };
if (k == nkind.N_RETURN) { coercefloatlit(c, n.lhs, c.fnret); };
// A.6.0: post-order dispatch of exprtype on every expression-yielding
// node kind so n.type_ stamps fire universally — not only when reached
// through checkletassign / checkretassign / checktryprop / the size-
// align-offset fold. Mirrors cstage cmd/wcc/check.c cstmt's recursive
// cexpr (cmd/wcc/check.c:1567 N_EXPRSTMT, :1570 N_RETURN, :1584 N_IF
// cond, etc.). Plumbing-only: stamps fire from existing exprtype kind
// arms (literals + idents); per-kind stamp coverage lands in A.6.1.
// Stamps are tinfocache-backed idempotent so multi-walk via let /
// return / try entry points is safe. N_DOT is dispatched in its own
// early-return branch above; not listed here. N_LET / N_RETURN /
// N_EXPRSTMT / N_IF / N_FOR / N_FORRANGE / N_BLOCK / N_MATCH-as-stmt
// are not value-typed nodes; their expression children get stamped on
// the recursive descent into them. Type-expression kinds (N_T*) are
// covered separately by the tinfofornode block above.
if (k == nkind.N_INTLIT || k == nkind.N_FLOATLIT ||
k == nkind.N_STRLIT || k == nkind.N_RUNELIT ||
k == nkind.N_TRUE || k == nkind.N_FALSE ||
k == nkind.N_NIL || k == nkind.N_VOIDLIT ||
k == nkind.N_IDENT || k == nkind.N_BIN ||
k == nkind.N_UN || k == nkind.N_CALL ||
k == nkind.N_INDEX || k == nkind.N_CAST ||
k == nkind.N_STRUCTLIT || k == nkind.N_ARRLIT ||
k == nkind.N_RECV ||
k == nkind.N_SLICE || k == nkind.N_SPREAD ||
k == nkind.N_TUPLE || k == nkind.N_TRYPROP ||
k == nkind.N_TRYUNW || k == nkind.N_TYPETEST ||
k == nkind.N_TYPEASSERT || k == nkind.N_YIELD ||
k == nkind.N_MATCH) {
let _t: *node = exprtype(c, n, nil);
};
};
// ---- type-level helpers (AST-level, no resolved tinfo) --------------
//
// The selfhost check operates on AST type expressions rather than
// resolved Type structs. These helpers mirror what cmd/wcc/check.c
// does with tinfo, but only on the subset of cases this checker
// needs to enforce: tagged-union exhaustiveness, ? subset
// propagation, and !-flag semantics.
// unwrapbang — strip an nkind.N_TBANG wrapper; leaves other nodes alone.
fn unwrapbang(n: *node) *node = {
if (n == nil) { return nil; };
if (n.kind == nkind.N_TBANG) { return n.lhs; };
return n;
};
// aliassym — resolve a single nkind.N_TNAME to its IMMEDIATE type
// symbol (one level, no chain walk). Returns nil for non-TNAME nodes,
// unresolvable names, or non-SK_TYPE bindings. #64 factors the lookup
// out of resolvealias so tinfofornode's TY_NAMED build can reach the
// decl sym (nominal identity = sym.type_ ptr-identity) instead of
// flattening to the underlying. Mirrors cstage resolve_typename
// (cmd/wcc/check.c:60-88), which returns the sym's NAMED, not the base.
fn aliassym(c: *checker, n: *node) *sym = {
if (n == nil) { return nil; };
if (n.kind != nkind.N_TNAME) { return nil; };
let nm: str = n.str;
// #51: pkg.alias type refs land here as a single TNAME whose
// str is the joined form (lib/ww/parse/parse.ww:258-265 in
// parsetype). Split on the rightmost '.' and bind the leaf in
// the head module's scope. Mirrors cstage resolve_typename
// cmd/wcc/check.c:74-83 strrchr branch — without this the
// raw `os.oserror` lookup misses and checkisas false-positives
// every cross-module tagged scrutinee.
let dotidx: i32 = -1;
let i: i32 = 0;
for (i < nm.len) {
if (nm[i] == 46u8) { dotidx = i; };
i += 1;
};
let s: *sym = nil;
if (dotidx >= 0) {
let head: str;
head.ptr = nm.ptr;
head.len = dotidx;
let leaf: str;
leaf.ptr = nm.ptr + ((dotidx + 1): u64);
leaf.len = nm.len - dotidx - 1;
s = scopelookupinmodule(c.cur, head, leaf);
} else {
// #53: same-module preference. Mirrors cstage
// cmd/wcc/check.c:66 scope_lookup_prefer. Without this,
// two modules each declaring `type invalid = ...` collide
// on the head-first bucket walk: e.g. utf8.invalid `!void`
// vs strconv.invalid `!i32` resolves to whichever
// registered first, driving localloadop MOVSXD/MOVQ
// divergence at 994/995. Other bare-leaf callers in this
// file (L1597 exprtype N_IDENT, L1795/L2720 N_DOT-callee
// leaf, L600 varianterr, L647 scruttype) tracked as #55.
s = scopelookupprefer(c.cur, c.curmod, nm);
// #61 A.5: bare TNAME that collides with an imported
// module bareword. Two shapes hit this:
// - `let l: lex;` where `lex` struct lives in
// `package lex;` (mod matches leaf).
// - `let t: tok;` where `tok` struct lives in
// `package lex;` (mod differs from leaf — tok.ww
// declares `package lex;`).
// scopelookup bucket-walks the flat scope and can land
// on the SK_USE entry first; without the fallback we'd
// return the unresolved TNAME and tinfofornode aborts on
// body == n. scopelookuptype walks the same bucket but
// filters on SK_TYPE so the struct entry surfaces
// regardless of its declaring package. Mirrors the
// bare-vs-qualified pattern from task #57.
if (s != nil) {
if (s.skind != skind.SK_TYPE) {
let sm: *sym = scopelookuptype(c.cur, nm);
if (sm != nil) { s = sm; };
};
};
};
if (s == nil) { return nil; };
if (s.skind != skind.SK_TYPE) { return nil; };
return s;
};
// resolvealias — if n is an nkind.N_TNAME pointing at a typedecl, return
// the typedecl's body (possibly recursively). Pass-through for any
// other node. The chain stops once we hit a non-nkind.N_TNAME node or a
// name we can't resolve.
fn resolvealias(c: *checker, n: *node) *node = {
let cur: *node = n;
for (cur != nil) {
if (cur.kind != nkind.N_TNAME) { return cur; };
let s: *sym = aliassym(c, cur);
if (s == nil) { return cur; };
let body: *node = nil;
if (s.decl != nil) { body = s.decl.lhs; };
if (body == nil) { return cur; };
cur = unwrapbang(body);
};
return n;
};
// typeeqast — structural equality on AST type expressions, mod
// the `!` wrapper. Mirrors variant_match in cgen + check.c: NAMED
// types compare by string (the closest stand-in for pointer
// identity at the AST level); other nodes recurse by kind.
fn typeeqast(a: *node, b: *node) bool = {
let aa: *node = unwrapbang(a);
let bb: *node = unwrapbang(b);
if (aa == nil) { return bb == nil; };
if (bb == nil) { return false; };
if (aa.kind != bb.kind) { return false; };
let k: nkind = aa.kind;
if (k == nkind.N_TNAME) { return streq(aa.str, bb.str); };
if (k == nkind.N_TPTR) { return typeeqast(aa.lhs, bb.lhs); };
if (k == nkind.N_TSLICE){ return typeeqast(aa.lhs, bb.lhs); };
if (k == nkind.N_TCHAN) { return typeeqast(aa.lhs, bb.lhs); };
if (k == nkind.N_TFN) {
// Divergence: cstage type.c:239 compares resolved Type; we
// compare AST. See #178.
if (!typeeqast(aa.lhs, bb.lhs)) { return false; };
let pa: *node = aa.list;
let pb: *node = bb.list;
for (pa != nil) {
if (pb == nil) { return false; };
let ac: bool = streq(pa.str, "...");
let bc: bool = streq(pb.str, "...");
if (ac != bc) { return false; };
if (!ac) {
let va: bool = pa.op == tkind.TK_ELLIPSIS;
let vb: bool = pb.op == tkind.TK_ELLIPSIS;
if (va != vb) { return false; };
if (!typeeqast(pa.lhs, pb.lhs)) { return false; };
};
pa = pa.next;
pb = pb.next;
};
return pb == nil;
};
// Conservative: anything else (struct/tagged/tuple/array) fails
// the cheap check. Selfhost code doesn't currently rely on
// equality at these shapes for the targeted checks.
return false;
};
// varianterr — does this variant carry the `!` mark? Either
// the variant itself is nkind.N_TBANG or it's an alias whose typedecl
// body is `!T`. Mirrors C check.c's iserror-after-NAMED rule.
fn varianterr(c: *checker, v: *node) bool = {
if (v == nil) { return false; };
if (v.kind == nkind.N_TBANG) { return true; };
if (v.kind == nkind.N_TNAME) {
let s: *sym = scopelookup(c.cur, v.str);
if (s != nil) {
if (s.skind == skind.SK_TYPE) {
if (s.decl != nil) {
if (s.decl.lhs != nil) {
if (s.decl.lhs.kind == nkind.N_TBANG) {
return true;
};
};
};
};
};
};
return false;
};
// taggedhaserr — true iff any variant of `n` (assumed
// nkind.N_TTAGGED) is `!`-marked. Picks the explicit-flag semantics over
// the legacy "first variant = success" rule.
fn taggedhaserr(c: *checker, n: *node) bool = {
let v: *node = n.list;
for (v != nil) {
if (varianterr(c, v)) { return true; };
v = v.next;
};
return false;
};
// iserrvariant — under flag-aware mode (any !-marked variant),
// returns true iff `v` is `!`-marked. Under legacy mode (no flags),
// returns true iff `v` is not the first variant of `tagged`.
fn iserrvariant(c: *checker, tagged: *node, v: *node) bool = {
if (taggedhaserr(c, tagged)) {
return varianterr(c, v);
};
// Legacy: first variant of the union is success.
if (tagged.list == v) { return false; };
return true;
};
// scruttype — resolve the type expression for a match's
// scrutinee. Handles nkind.N_IDENT (look up local/param's declared
// type) and nkind.N_DOT (module-qualified ref). Returns nil if we
// can't statically determine the type. Used by exhaustiveness.
fn scruttype(c: *checker, e: *node) *node = {
if (e == nil) { return nil; };
if (e.kind == nkind.N_IDENT) {
let s: *sym = scopelookup(c.cur, e.str);
if (s == nil) { return nil; };
if (s.decl == nil) { return nil; };
// For nkind.N_LET / nkind.N_PARAM: declared type is decl.lhs.
return s.decl.lhs;
};
// #51: `match (pkg.var)` / `pkg.var is T` — module-qualified ref.
// lhs is N_IDENT (module bareword), str is the leaf. Bind via
// scopelookupinmodule so the declared type carries the same
// shape resolvealias' dotted-name branch now consumes. Falls
// silently to nil when lhs is a value (struct-field access) —
// the rest of the lenient-check contract.
if (e.kind == nkind.N_DOT) {
if (e.lhs == nil) { return nil; };
if (e.lhs.kind != nkind.N_IDENT) { return nil; };
let s: *sym = scopelookupinmodule(c.cur, e.lhs.str, e.str);
if (s == nil) { return nil; };
if (s.decl == nil) { return nil; };
return s.decl.lhs;
};
return nil;
};
// mktname — fabricate an nkind.N_TNAME node with str = `nm`. Used by
// exprtype to return primitive type nodes for literal
// expressions. The arena keeps them around as long as the checker.
fn mktname(c: *checker, nm: str) *node = {
let n: *node = newnode(nkind.N_TNAME, "", 0, 0);
n.str = nm;
return n;
};
// #43: SSoT for primitive type byte sizes. astsize's N_TNAME-primitive
// arm and every wwstage cgen size walker (slotsize/fieldsize/letemit-
// size/elemsizeof/paramfieldsize) consult this table so a future
// ty_str.size bump (#1) lands in one place. Returns -1 for non-prim
// names; callers fall back to alias/struct/enum lookup. Cstage's
// equivalent SSoT is cmd/wcc/type.c:46-79 (ty_void/ty_bool/.../ty_str).
fn primtypesize(nm: str) i64 = {
if (streq(nm, "void")) { return 0i64; };
if (streq(nm, "bool")) { return 1i64; };
if (streq(nm, "i8") || streq(nm, "u8")) { return 1i64; };
if (streq(nm, "i16") || streq(nm, "u16")) { return 2i64; };
if (streq(nm, "i32") || streq(nm, "u32") || streq(nm, "f32") || streq(nm, "rune")) { return 4i64; };
if (streq(nm, "i64") || streq(nm, "u64") || streq(nm, "f64")) { return 8i64; };
if (streq(nm, "int") || streq(nm, "uint") || streq(nm, "uintptr") || streq(nm, "size")) { return 8i64; };
// str IS []u8: 24B, sourced from the slice header SSoT so str and
// []u8 can never drift; no second hardcoded 24 (#1/Phase 3).
if (streq(nm, "str")) { return tyslicesize(); };
return -1i64;
};
// #43: SSoT for slice header size (ptr+len+cap = 24B today). Mirrors
// cstage cmd/wcc/type.c:103 (ty_slice->size = 24). Bumping a slice's
// header layout in #34 touches only this constant.
fn tyslicesize() i64 = { return 24i64; }; // sizelint-ok: SSoT for ty_slice header (#64)
// #42: AST-level layout helpers for the size(T)/align(T)/offset(e.f)
// fold. Mirror cstage resolve_type's size/align computation
// (cmd/wcc/check.c:286-528) on AST nodes — wwstage check.ww never
// materialises tinfo for user types so the fold has to walk the AST
// directly. Struct layout follows cstage check.c:471-526 (align each
// field, max align for the whole record, round size up to alignment).
fn astalign(c: *checker, t: *node) i64 = {
if (t == nil) { return 1i64; };
let k: nkind = t.kind;
if (k == nkind.N_TBANG) { return astalign(c, t.lhs); };
if (k == nkind.N_TPTR) { return 8i64; };
if (k == nkind.N_TSLICE) { return 8i64; };
if (k == nkind.N_TCHAN) { return 8i64; };
if (k == nkind.N_TFN) { return 8i64; };
if (k == nkind.N_TARRAY) { return astalign(c, t.lhs); };
if (k == nkind.N_TTAGGED) { return 8i64; };
if (k == nkind.N_TTUPLE) {
let m: i64 = 1i64;
let p: *node = t.list;
for (p != nil) {
let pa: i64 = astalign(c, p.lhs);
if (pa > m) { m = pa; };
p = p.next;
};
return m;
};
if (k == nkind.N_TSTRUCT) {
let m: i64 = 1i64;
let f: *node = t.list;
for (f != nil) {
if (f.kind == nkind.N_TFIELD) {
let fa: i64 = astalign(c, f.lhs);
if (fa > m) { m = fa; };
};
f = f.next;
};
return m;
};
if (k == nkind.N_TENUM) {
if (t.lhs != nil) { return astalign(c, t.lhs); };
return 4i64;
};
if (k == nkind.N_TNAME) {
let nm: str = t.str;
if (streq(nm, "void") || streq(nm, "bool") || streq(nm, "i8") || streq(nm, "u8")) { return 1i64; };
if (streq(nm, "i16") || streq(nm, "u16")) { return 2i64; };
if (streq(nm, "i32") || streq(nm, "u32") || streq(nm, "f32") || streq(nm, "rune")) { return 4i64; };
if (streq(nm, "i64") || streq(nm, "u64") || streq(nm, "f64") || streq(nm, "int") || streq(nm, "uint") || streq(nm, "uintptr") || streq(nm, "size") || streq(nm, "str")) { return 8i64; };
let resolved: *node = resolvealias(c, t);
if (resolved != nil && resolved != t) {
return astalign(c, resolved);
};
};
return 1i64;
};
fn astsize(c: *checker, t: *node) i64 = {
if (t == nil) { return 0i64; };
let k: nkind = t.kind;
if (k == nkind.N_TBANG) { return astsize(c, t.lhs); };
if (k == nkind.N_TPTR) { return 8i64; };
if (k == nkind.N_TSLICE) { return tyslicesize(); };
if (k == nkind.N_TCHAN) { return 8i64; };
if (k == nkind.N_TFN) { return 8i64; };
if (k == nkind.N_TARRAY) {
let elen: i64 = 0i64;
if (t.rhs != nil) {
if (t.rhs.kind == nkind.N_INTLIT) { elen = t.rhs.uval: i64; };
};
return astsize(c, t.lhs) * elen;
};
if (k == nkind.N_TTUPLE) {
let total: i64 = 0i64;
let p: *node = t.list;
for (p != nil) {
total += astsize(c, p.lhs);
p = p.next;
};
return total;
};
if (k == nkind.N_TSTRUCT) {
let off: i64 = 0i64;
let maxal: i64 = 1i64;
let f: *node = t.list;
for (f != nil) {
if (f.kind == nkind.N_TFIELD) {
let fa: i64 = astalign(c, f.lhs);
if (fa > maxal) { maxal = fa; };
off = (off + fa - 1i64) & ~(fa - 1i64);
off += astsize(c, f.lhs);
};
f = f.next;
};
return (off + maxal - 1i64) & ~(maxal - 1i64);
};
if (k == nkind.N_TTAGGED) {
// 8 (tag) + max variant payload, rounded up to 8.
let maxsz: i64 = 0i64;
let v: *node = t.list;
for (v != nil) {
let sz: i64 = astsize(c, v);
if (sz > maxsz) { maxsz = sz; };
v = v.next;
};
let pad: i64 = (maxsz + 7i64) & ~7i64;
return 8i64 + pad;
};
if (k == nkind.N_TENUM) {
if (t.lhs != nil) { return astsize(c, t.lhs); };
return 4i64;
};
if (k == nkind.N_TNAME) {
let nm: str = t.str;
let ps: i64 = primtypesize(nm);
if (ps >= 0i64) { return ps; };
let resolved: *node = resolvealias(c, t);
if (resolved != nil && resolved != t) {
return astsize(c, resolved);
};
};
return 0i64;
};
// astunsized — #108(b): true iff `t` contains an unsized component. A
// type is unsized iff it is the abstract `opaque` (size/align ==
// SIZE_UNDEFINED) OR an aggregate (array / struct / tuple / tagged)
// with a recursively-unsized member. The wwstage has NO type-decl
// construction guards (those are cstage-only, rule-10), so its size()/
// align() FOLD must detect every opaque-containing type itself — a
// leaf-only check would silently fold size([4]opaque) / size(struct{x:
// opaque}) / size((opaque, i32)) to garbage (rule 7). Does NOT peel
// TPTR/TSLICE/TCHAN/TFN — `*opaque` (8B) and `[]opaque` (24B header)
// are sized and legal behind indirection. Cstage twin: the leaf
// `m == SIZE_UNDEFINED` size/align guard PLUS the per-construction
// require_sized guards that reject unsized aggregates at the type decl
// (so the cstage size/align fold only ever sees a leaf opaque); harec
// ref/harec/src/check.c:2720, type_store.c:1147 (tuple) / :449 (tagged).
fn astunsized(c: *checker, t: *node) bool = {
if (t == nil) { return false; };
let u: *node = resolvealias(c, unwrapbang(t));
if (u == nil) { return false; };
let k: nkind = u.kind;
if (k == nkind.N_TNAME) {
if (streq(u.str, "opaque")) { return true; };
return false;
};
if (k == nkind.N_TARRAY) { return astunsized(c, u.lhs); };
if (k == nkind.N_TTUPLE) {
let p: *node = u.list;
for (p != nil) {
if (astunsized(c, p.lhs)) { return true; };
p = p.next;
};
return false;
};
if (k == nkind.N_TSTRUCT) {
let f: *node = u.list;
for (f != nil) {
if (f.kind == nkind.N_TFIELD) {
if (astunsized(c, f.lhs)) { return true; };
};
f = f.next;
};
return false;
};
if (k == nkind.N_TTAGGED) {
let v: *node = u.list;
for (v != nil) {
if (astunsized(c, v)) { return true; };
v = v.next;
};
return false;
};
return false;
};
// matchyieldtype — port of cstage cmd/wcc/check.c:110-135. Walks a
// match arm body for the first `yield expr;` and returns its operand
// type. Returns nil if no yield is reachable from `body`. Doesn't
// descend into a nested N_MATCH — each match opens its own yield
// scope. exprtype is idempotent on already-stamped nodes (tinfocache
// path at L467) so re-entering it on the yield operand here is safe.
fn matchyieldtype(c: *checker, body: *node) *node = {
if (body == nil) { return nil; };
let k: nkind = body.kind;
if (k == nkind.N_YIELD) {
if (body.lhs == nil) { return nil; };
return exprtype(c, body.lhs, nil);
};
if (k == nkind.N_MATCH) { return nil; };
if (k == nkind.N_BLOCK) {
let s: *node = body.list;
for (s != nil) {
let t: *node = matchyieldtype(c, s);
if (t != nil) { return t; };
s = s.next;
};
return nil;
};
if (k == nkind.N_IF) {
let t: *node = matchyieldtype(c, body.body);
if (t != nil) { return t; };
return matchyieldtype(c, body.els);
};
if (k == nkind.N_FOR || k == nkind.N_FORRANGE) {
return matchyieldtype(c, body.body);
};
return nil;
};
// astoffset — byte offset of `dot.str` inside the struct type of
// `dot.lhs`. Mirrors cstage cmd/wcc/check.c:932-961: peel one N_TPTR
// (for `p.field` where p is *Struct), require N_TSTRUCT, walk fields
// honouring per-field alignment, return -1 if the field name is
// absent so the caller can flag the error and fold to 0.
fn astoffset(c: *checker, dot: *node) i64 = {
if (dot == nil) { return -1i64; };
if (dot.kind != nkind.N_DOT) { return -1i64; };
let recv: *node = scruttype(c, dot.lhs);
if (recv == nil) { return -1i64; };
let rtyp: *node = resolvealias(c, unwrapbang(recv));
if (rtyp == nil) { return -1i64; };
if (rtyp.kind == nkind.N_TPTR) {
rtyp = resolvealias(c, unwrapbang(rtyp.lhs));
};
if (rtyp == nil) { return -1i64; };
if (rtyp.kind != nkind.N_TSTRUCT) { return -1i64; };
let off: i64 = 0i64;
let f: *node = rtyp.list;
for (f != nil) {
if (f.kind == nkind.N_TFIELD) {
let fa: i64 = astalign(c, f.lhs);
off = (off + fa - 1i64) & ~(fa - 1i64);
if (streq(f.str, dot.str)) { return off; };
off += astsize(c, f.lhs);
};
f = f.next;
};
return -1i64;
};
// arenau64tos — decimal string for the folded INTLIT's `str` field.
// Cstage uses aprintf("%llu") at the same site (cmd/wcc/check.c:921);
// wwstage cgen only reads `uval` for N_INTLIT codegen so `str` is
// just for the AST printer, but set it for parity with the parser's
// own literal-emit shape.
fn arenau64tos(v: u64) str = {
let buf: []u8 = alloc([], 24u64)!;
let i: i32 = 23;
buf[i] = 0u8;
if (v == 0u64) { i -= 1; buf[i] = 48u8; };
let n: u64 = v;
for (n > 0u64) {
i -= 1;
buf[i] = (48u64 + (n % 10u64)): u8;
n /= 10u64;
};
let r: str;
r.ptr = buf.ptr + (i: u64);
r.len = 23 - i;
return r;
};
// foldtointlit — mutate `n` in place to an N_INTLIT with value `v`.
// Used by the #42 size/align/offset intercepts so cgen sees the
// folded literal rather than an unresolved call. Mirrors cstage
// cmd/wcc/check.c:919-927 / :951-958.
fn foldtointlit(c: *checker, n: *node, v: i64) void = {
n.kind = nkind.N_INTLIT;
n.uval = v: u64;
n.str = arenau64tos(v: u64);
n.lhs = nil;
n.list = nil;
let empty: str;
n.tsuffix = empty;
};
// foldbinop — shared constant binary-op core for the two compile-time
// integer evaluators in this file: enumvalfold (enum member exprs) and
// evaldefconst (top-level def rhs, #88). One op table so the cstage
// (cmd/wcc/check.c fold_binop) and wwstage stamp the bit-identical
// literal — rule 10 lives at the check pass for #88. Returns false on
// division by zero or an op outside the constant subset; the caller
// maps that to its own diagnostic.
fn foldbinop(op: tkind, a: u64, b: u64, out: *u64) bool = {
if (op == tkind.TK_PLUS) { *out = a + b; return true; };
if (op == tkind.TK_MINUS) { *out = a - b; return true; };
if (op == tkind.TK_STAR) { *out = a * b; return true; };
if (op == tkind.TK_SLASH) {
if (b == 0u64) { return false; };
*out = a / b; return true;
};
if (op == tkind.TK_PERCENT) {
if (b == 0u64) { return false; };
*out = a % b; return true;
};
if (op == tkind.TK_AMP) { *out = a & b; return true; };
if (op == tkind.TK_PIPE) { *out = a | b; return true; };
if (op == tkind.TK_CARET) { *out = a ^ b; return true; };
if (op == tkind.TK_LSHIFT) { *out = a << b; return true; };
if (op == tkind.TK_RSHIFT) { *out = a >> b; return true; };
return false;
};
// deffolderr — loud diagnostic + checker error count bump for an
// unfoldable def rhs (cycle / narrowing-cast / bad op). c.errs > 0
// gates cgen off in main.ww:165, so this fails the build rather than
// emitting a missing DATA row silently (rule 7). cstage twin: err()
// in cmd/wcc/check.c.
fn deffolderr(c: *checker, n: *node, msg: str) void = {
os.write(2, n.file.ptr, n.file.len: u64);
os.write(2, ": error: ".ptr, 9u64);
os.write(2, msg.ptr, msg.len: u64);
os.write(2, "\n".ptr, 1u64);
c.errs += 1;
};
// defcastfits — wwstage twin of cstage def_cast_fits (cmd/wcc/check.c):
// does the folded u64 `v` survive narrowing to integer target `t`?
// Identity / widening / same-width casts always fit; a genuine
// narrowing cast whose value falls outside the target range must NOT
// be silently truncated (rule 7 / drew). Width via the type table
// (t.size, rule 13); the 8s are CHAR_BIT and the u64 byte-width, not
// type-layout sizes, so they sit outside rule 13's scope. Pure-u64 so
// the range check is bit-identical to cstage (rule 10).
fn defcastfits(t: *tinfo, v: u64) bool = {
if (!typeisint(t)) { return true; }; // non-int target: keep value
let w: u64 = t.size;
if (w >= 8u64) { return true; }; // 64-bit target: no narrowing
let bits: u64 = w * 8u64;
if (typeisunsigned(t)) { return (v >> bits) == 0u64; };
// signed: truncate to `bits` then sign-extend; fits iff unchanged
let mask: u64 = (1u64 << bits) - 1u64;
let sign: u64 = 1u64 << (bits - 1u64);
let ext: u64 = ((v & mask) ^ sign) - sign;
return ext == v;
};
// evaldefconst — fold a top-level def's rhs to a u64 constant,
// resolving sibling and imported def references, casts, and
// arithmetic (#88). Reuses foldintliteral (leaf/unary) + foldbinop
// (arith); the ONLY thing it does that enumvalfold doesn't is resolve
// an identifier through the checker's flat scope (scopelookupprefer
// for a bare sibling ref, scopelookupinmodule for `mod.NAME`) to the
// referent def's own rhs, then recurse.
//
// Why this stays distinct from enumvalfold rather than a full merge
// (rule 8 WHY): enum-member eval carries implicit prev+1 auto-increment
// and forward-only sibling lookup over the member chain; def eval has
// neither — it resolves through the scope/decl graph, which references
// forward and across modules. The two lookup models don't reconcile
// cleanly, so they share the arith core (foldbinop) + leaf fold
// (foldintliteral) and keep separate top-level shapes.
//
// `depth` bounds a def->def->def chain; a cycle (def A = B; def B = A,
// incl. cross-module) hits the cap and fails loud rather than hanging
// (rule 7), mirroring the cgen nsteps>=16 abort precedent.
fn evaldefconst(c: *checker, n: *node, out: *u64, depth: i32) bool = {
if (n == nil) { return false; };
if (depth >= 16) {
deffolderr(c, n, "def value: reference chain too deep (cycle?)");
return false;
};
if (foldintliteral(n, out)) { return true; };
let k: nkind = n.kind;
if (k == nkind.N_BIN) {
let a: u64 = 0u64;
let b: u64 = 0u64;
if (!evaldefconst(c, n.lhs, &a, depth + 1)) { return false; };
if (!evaldefconst(c, n.rhs, &b, depth + 1)) { return false; };
if (foldbinop(n.op, a, b, out)) { return true; };
if ((n.op == tkind.TK_SLASH || n.op == tkind.TK_PERCENT) && b == 0u64) {
deffolderr(c, n, "def value: division by zero");
} else {
deffolderr(c, n, "def value: unsupported binary op");
};
return false;
};
if (k == nkind.N_UN) {
// foldintliteral already covers unary-over-leaf; this arm
// catches unary over a resolved ref, e.g. `-A`.
let v: u64 = 0u64;
if (!evaldefconst(c, n.lhs, &v, depth + 1)) { return false; };
if (n.op == tkind.TK_MINUS) { *out = (-(v: i64)): u64; return true; };
if (n.op == tkind.TK_TILDE) { *out = ~v; return true; };
if (n.op == tkind.TK_PLUS) { *out = v; return true; };
deffolderr(c, n, "def value: unsupported unary op");
return false;
};
if (k == nkind.N_CAST) {
// n.lhs = value; n.type_ = resolved target (stamped by
// exprtype's N_CAST arm during resolvewalk). Strip the cast
// keeping the value; a narrowing cast that loses it fails loud.
let v: u64 = 0u64;
if (!evaldefconst(c, n.lhs, &v, depth + 1)) { return false; };
let t: *tinfo = (n.type_): *tinfo;
if (!defcastfits(t, v)) {
deffolderr(c, n, "def value: narrowing cast loses value");
return false;
};
*out = v;
return true;
};
if (k == nkind.N_IDENT) {
let s: *sym = scopelookupprefer(c.cur, c.curmod, n.str);
if (s == nil) { return false; };
if (s.skind != skind.SK_DEF) { return false; };
if (s.decl == nil) { return false; };
if (s.decl.rhs == nil) { return false; };
return evaldefconst(c, s.decl.rhs, out, depth + 1);
};
if (k == nkind.N_DOT) {
if (n.lhs == nil) { return false; };
if (n.lhs.kind != nkind.N_IDENT) { return false; };
let s: *sym = scopelookupinmodule(c.cur, n.lhs.str, n.str);
if (s == nil) { return false; };
if (s.skind != skind.SK_DEF) { return false; };
if (s.decl == nil) { return false; };
if (s.decl.rhs == nil) { return false; };
return evaldefconst(c, s.decl.rhs, out, depth + 1);
};
return false;
};
// stampintlit — rewrite a const-folded def rhs in place to its literal
// value, preserving the node's resolved type_ so the DATA-row emit
// width and pass-3 asserttyped see a properly-typed literal leaf. Lets
// cgen's existing emitdefconstants lay down the row with no codegen
// change (#88). Shape mirrors foldtointlit (the #42 stamp).
fn stampintlit(n: *node, v: u64) void = {
n.kind = nkind.N_INTLIT;
n.uval = v;
n.op = tkind.TK_NONE;
n.str = arenau64tos(v);
n.lhs = nil;
n.rhs = nil;
n.cond = nil;
n.body = nil;
n.els = nil;
n.list = nil;
let empty: str;
n.tsuffix = empty;
// n.type_ left intact (the type exprtype inferred for the rhs).
};
// enumvalfold — fold an enum member's value expression to a u64
// constant. The Hare-fidelity set: literal leaves, unary +/-/~,
// binary arithmetic (+ - * / %), bitwise (& | ^), shifts (<< >>),
// and sibling backref. Mirrors cstage cmd/wcc/check.c:185-208
// (fold_int_literal) + :210-284 (eval_enum_value); the wider
// constexpr evaluator is at ref/harec/src/eval.c (harec resolves
// each enum member via eval_expr per ref/harec/src/check.c:4419-
// 4434). Wwstage cgen.ww:158-227 (foldintliteral + enumevalmember)
// already ships this set for codegen — check now matches.
//
// `body` is the N_TENUM whose .list is the member chain. `until`
// is the member currently being resolved; sibling lookup walks
// forward from body.list and stops at `until` to enforce harec's
// lnext forward-only-ref discipline (ref/harec/src/check.c:4436-
// 4438). `e` starts as that member's lhs and recurses into its
// children. Returns false on unfoldable shape, unknown sibling,
// or division by zero — callers bail the wrapping N_DOT fold.
//
// Recursion bound: O(N²) worst case on chained sibling backrefs
// (each ident lookup re-walks 0..until). Enum bodies are tiny in
// practice — harec accepts the same shape without memoisation per
// resolve_enum_field's wrap_resolver chain
// (ref/harec/src/check.c:4438) — so the quadratic is harmless.
fn enumvalfold(body: *node, until: *node, e: *node, out: *u64) bool = {
if (e == nil) { return false; };
let k: nkind = e.kind;
if (k == nkind.N_INTLIT) { *out = e.uval; return true; };
if (k == nkind.N_RUNELIT) { *out = e.uval; return true; };
if (k == nkind.N_TRUE) { *out = 1u64; return true; };
if (k == nkind.N_FALSE) { *out = 0u64; return true; };
if (k == nkind.N_NIL) { *out = 0u64; return true; };
if (k == nkind.N_UN) {
let v: u64 = 0u64;
if (!enumvalfold(body, until, e.lhs, &v)) { return false; };
let op: tkind = e.op;
if (op == tkind.TK_MINUS) { *out = (-(v: i64)): u64; return true; };
if (op == tkind.TK_TILDE) { *out = ~v; return true; };
if (op == tkind.TK_PLUS) { *out = v; return true; };
return false;
};
if (k == nkind.N_BIN) {
let a: u64 = 0u64;
let b: u64 = 0u64;
if (!enumvalfold(body, until, e.lhs, &a)) { return false; };
if (!enumvalfold(body, until, e.rhs, &b)) { return false; };
return foldbinop(e.op, a, b, out);
};
if (k == nkind.N_IDENT) {
let prev: u64 = (-1i64): u64;
let m: *node = body.list;
for (m != nil && m != until) {
let val: u64 = 0u64;
if (m.lhs == nil) {
val = prev + 1u64;
} else {
if (!enumvalfold(body, m, m.lhs, &val)) { return false; };
};
prev = val;
if (streq(m.str, e.str)) { *out = val; return true; };
m = m.next;
};
return false;
};
return false;
};
// stampenumvals — give every node in each enum-member value-expr a
// non-nil type_. resolvewalk's post-order exprtype (L543) stamps the
// literal leaves, but a sibling backref (`B = A + 4`) resolves to
// nothing — enum members aren't installed as scope idents — so the
// backref N_IDENT and the N_BIN/N_UN wrapping it stay nil. asserttyped
// walks the enum DEFINITION (whether or not a member is `.`-accessed)
// and its value-node invariant then fires on those. harec checks each
// member's value-expr at the enum's underlying type
// (ref/harec/src/check.c:4419 — check_expression with type->alias.type),
// so the whole constant subtree carries the underlying integer type;
// mirror that. The value itself is folded to a constant at every use
// site (enumvalfold) and at codegen (cgen.ww enumevalmember), so cgen
// never reads these node types — this stamp is checker metadata only.
fn stampenumvals(c: *checker, n: *node) void = {
let under: *tinfo = c.tc.tyi32;
if (n.lhs != nil) {
let s: *tinfo = tinfofornode(c, n.lhs);
if (s != nil) { under = s; };
};
let m: *node = n.list;
for (m != nil) {
stampnilexpr(m.lhs, under);
m = m.next;
};
};
// stampnilexpr — stamp nil-typed nodes in a constant expr subtree to
// `ti`. lhs/rhs cover the enum constexpr grammar enumvalfold accepts
// (literals, unary, binary, sibling backref); non-nil nodes keep the
// type exprtype already derived.
fn stampnilexpr(n: *node, ti: *tinfo) void = {
if (n == nil) { return; };
if (n.type_ == nil) { n.type_ = ti: *void; };
stampnilexpr(n.lhs, ti);
stampnilexpr(n.rhs, ti);
};
// #61 A.5 helper: per-element slot size when `pt` appears inside a
// tuple. Mirrors cgenutil.ww slotsize TTUPLE — cstage's tuple ABI
// spills each element into its own register / 8B eightbyte, so narrow
// scalars pad to 8 (cgen's let_emit_size + AX:DX:CX positional layout).
// str/slice and composites consult `pt.size` so a future #1 bump on
// any primitive layout propagates through the typ.ww SSoT seed
// instead of getting baked into this detour. pointer/fn/chan stay
// 8; void contributes 0 (never appears in tuples emitted by user
// code, but kept for SSoT symmetry with cgen's N_TNAME-"void"
// fallback arm).
fn tupleelemslot(pt: *tinfo) u64 = {
if (pt == nil) { return 8u64; };
// #63 Phase-N step 1: peel TY_NAMED before this structural query.
// #64 builds per-decl NAMED wrappers (tinfofornode), so the peel
// now fires on aliased operands; byte-id holds because it collapses
// NAMED to the alias-invariant underlying this read consumes.
let t: *tinfo = pt;
for (t != nil && t.kind == tykind.TY_NAMED) { t = t.under; };
if (t == nil) { return 8u64; };
let pk: tykind = t.kind;
if (pk == tykind.TY_VOID) { return 0u64; };
if (pk == tykind.TY_STR) { return t.size; };
if (pk == tykind.TY_SLICE) { return t.size; };
if (pk == tykind.TY_PTR || pk == tykind.TY_FN ||
pk == tykind.TY_CHAN || pk == tykind.TY_I64 ||
pk == tykind.TY_U64 || pk == tykind.TY_INT ||
pk == tykind.TY_UINT || pk == tykind.TY_UINTPTR ||
pk == tykind.TY_SIZE || pk == tykind.TY_F64) { return 8u64; };
if (pk == tykind.TY_BOOL || pk == tykind.TY_RUNE ||
pk == tykind.TY_I8 || pk == tykind.TY_I16 ||
pk == tykind.TY_I32 || pk == tykind.TY_U8 ||
pk == tykind.TY_U16 || pk == tykind.TY_U32 ||
pk == tykind.TY_F32 || pk == tykind.TY_ENUM) { return 8u64; };
// Composite — struct/tuple/array/tagged carry their own slot total.
return t.slotsize;
};
// #61 A.5 helper: per-field slot size mirroring cgenutil.ww
// registerstruct/fieldsize. Nested struct fields contribute their
// slot-padded total (si.totsize equivalent); primitives keep their
// natural width (struct interior packing is unaffected by stack-slot
// pad-to-8); arrays use their slot-padded element-stride * elen.
fn fieldslotsize(ft: *tinfo) u64 = {
if (ft == nil) { return 8u64; };
// #63 Phase-N step 1: peel TY_NAMED before this structural query.
// #64 builds per-decl NAMED wrappers (tinfofornode), so the peel
// now fires on aliased operands; byte-id holds because it collapses
// NAMED to the alias-invariant underlying this read consumes.
let t: *tinfo = ft;
for (t != nil && t.kind == tykind.TY_NAMED) { t = t.under; };
if (t == nil) { return 8u64; };
let fk: tykind = t.kind;
if (fk == tykind.TY_STRUCT) { return t.slotsize; };
if (fk == tykind.TY_ARRAY) { return t.slotsize; };
if (fk == tykind.TY_TAGGED) { return t.size; };
// str / slice read t.size so the typ.ww SSoT seed is the single
// source for #1 (str→24) / #34 (slice graduation) — no hardcoded
// literal here to drift.
if (fk == tykind.TY_SLICE) { return t.size; };
if (fk == tykind.TY_PTR || fk == tykind.TY_FN ||
fk == tykind.TY_CHAN) { return 8u64; };
if (fk == tykind.TY_STR) { return t.size; };
// Primitives keep natural width inside structs (matches
// cgenutil fieldsize: primsize, not pad-to-8). TY_TUPLE inside a
// struct currently defaults to 8 in cgenutil — preserve that
// shape until a future graduation aligns the two.
if (fk == tykind.TY_BOOL || fk == tykind.TY_RUNE ||
fk == tykind.TY_I8 || fk == tykind.TY_I16 ||
fk == tykind.TY_I32 || fk == tykind.TY_I64 ||
fk == tykind.TY_U8 || fk == tykind.TY_U16 ||
fk == tykind.TY_U32 || fk == tykind.TY_U64 ||
fk == tykind.TY_INT || fk == tykind.TY_UINT ||
fk == tykind.TY_UINTPTR || fk == tykind.TY_SIZE ||
fk == tykind.TY_F32 || fk == tykind.TY_F64 ||
fk == tykind.TY_ENUM) { return t.size; };
return 8u64;
};
// #61 audit §1.8 — resolve a type-expression AST node to its *tinfo.
// Mirrors cstage's resolve_type (cmd/wcc/check.c:286-565) which
// produces ty_* singletons / arena-allocated composites from a Node*.
// Cache lives in c.tc (typ.ww) so the same shape can be reused across
// modules within one check pass. Rob+Drew convergence 2026-05-20: cgen
// reads sizes from here starting with slotsize in A.2; subsequent
// sub-commits graduate elemsize/fieldsize/letemitsize/etc. onto the
// same pivot.
//
// A.2 coverage: primitive TNAME singletons, TNAME aliases (via
// resolvealias), TBANG (inner unchanged — see iserror note), TPTR,
// TSLICE, TCHAN, TARRAY, TFN, TENUM, TTUPLE, TSTRUCT, TTAGGED. Size
// computation tracks cstage natural sizes; cgen's slot-padding
// contract (cmd/w6c/cgen.c let_emit_size:691-720 pads narrow scalars
// to 8B) stays in slotsize's fallback walker.
fn tinfofornode(c: *checker, n: *node) *tinfo = {
if (n == nil) { return nil; };
let cached: *tinfo = tinfocachelookup(c.tc, n);
if (cached != nil) { return cached; };
let r: *tinfo = nil;
let k: nkind = n.kind;
if (k == nkind.N_TNAME) {
let nm: str = n.str;
if (streq(nm, "void")) { r = c.tc.tyvoid; };
if (streq(nm, "bool")) { r = c.tc.tybool; };
if (streq(nm, "rune")) { r = c.tc.tyrune; };
if (streq(nm, "i8")) { r = c.tc.tyi8; };
if (streq(nm, "i16")) { r = c.tc.tyi16; };
if (streq(nm, "i32")) { r = c.tc.tyi32; };
if (streq(nm, "i64")) { r = c.tc.tyi64; };
if (streq(nm, "u8")) { r = c.tc.tyu8; };
if (streq(nm, "u16")) { r = c.tc.tyu16; };
if (streq(nm, "u32")) { r = c.tc.tyu32; };
if (streq(nm, "u64")) { r = c.tc.tyu64; };
if (streq(nm, "int")) { r = c.tc.tyint; };
if (streq(nm, "uint")) { r = c.tc.tyuint; };
if (streq(nm, "uintptr")) { r = c.tc.tyuintptr; };
if (streq(nm, "size")) { r = c.tc.tysize; }; // #85 fold-2
if (streq(nm, "opaque")) { r = c.tc.tyopaque; }; // #108(a)
if (streq(nm, "f32")) { r = c.tc.tyf32; };
if (streq(nm, "f64")) { r = c.tc.tyf64; };
if (streq(nm, "str")) { r = c.tc.tystr; };
if (streq(nm, "never")) { r = c.tc.tynever; };
if (streq(nm, "untyped_int")) { r = c.tc.tyuntypedint; };
if (streq(nm, "untyped_float")) { r = c.tc.tyuntypedfloat; };
if (streq(nm, "untyped_str")) { r = c.tc.tyuntypedstr; };
if (streq(nm, "untyped_rune")) { r = c.tc.tyuntypedrune; };
if (streq(nm, "untyped_bool")) { r = c.tc.tyuntypedbool; };
if (streq(nm, "untyped_nil")) { r = c.tc.tyuntypednil; };
if (r == nil) {
// #64 Phase-N step 2 (THE FLIP): build a per-decl
// TY_NAMED wrapper instead of collapsing the alias to
// its underlying. sym.type_ caches the wrapper so every
// TNAME resolving to the same decl yields the SAME tinfo
// pointer — ptr-identity IS nominal identity (the whole
// point; typeeq is the only consumer, wired in step 3).
// CHAINS, not flatten: under is the IMMEDIATE body's
// tinfo, so `type a = b` gives NAMED(a).under = NAMED(b)
// — mirrors cstage's two-phase type_named
// (cmd/wcc/check.c:1900-1929): pass1 creates the NAMED,
// pass2 patches under/size off resolve_type(d->lhs),
// where resolve_typename returns the inner NAMED.
let s: *sym = aliassym(c, n);
if (s != nil) {
if (s.type_ != nil) {
r = s.type_;
} else {
let body: *node = nil;
if (s.decl != nil) {
body = unwrapbang(s.decl.lhs);
};
if (body != nil) {
// PRE-BIND before resolving under: a
// self-referential field (`type node =
// struct {next: *node}`) re-finds this
// NAMED via sym.type_ instead of re-
// entering the chain. Mirrors cstage
// pass1's sym->type install
// (check.c:1909/1917) ahead of pass2's
// under patch, and A.2's TSTRUCT/TFN/
// TTAGGED tinfocachebind cycle-break.
let named: *tinfo = typenamed(s.name, nil);
s.type_ = named;
let under: *tinfo = tinfofornode(c, body);
named.under = under;
if (under != nil) {
named.size = under.size;
named.align = under.align;
named.slotsize = under.slotsize;
};
r = named;
};
};
};
};
} else { if (k == nkind.N_TBANG) {
// #61 audit §1.8: `!T` propagates the inner shape; cstage's
// resolve_type sets ty->iserror on the wrapper but no wwstage
// cgen reader consumes it yet, so A.1 drops the flag and
// returns the inner tinfo unchanged. Mirrors typeeqast's
// unwrapbang pre-walk; graduate alongside the first cgen
// site that needs iserror discrimination.
r = tinfofornode(c, n.lhs);
} else { if (k == nkind.N_TPTR) {
r = typeptr(tinfofornode(c, n.lhs));
} else { if (k == nkind.N_TSLICE) {
r = typeslice(tinfofornode(c, n.lhs));
} else { if (k == nkind.N_TCHAN) {
r = typechan(tinfofornode(c, n.lhs));
} else { if (k == nkind.N_TARRAY) {
// Cstage cmd/wcc/check.c:314-326: length must be an integer
// literal (`[_]T` keeps alen=0 as the inferred-length sentinel
// patched at letslotsize-time).
//
// #61 A.5: ti.size = natural (sub.size * elen), ti.slotsize =
// slot-padded (sub.slotsize * elen) — typearray handles both.
// Reverts A.4's r.size override (which conflated stride with
// natural size); the slot-padded stride now lives in slotsize
// where cgenutil's fast-path reads it.
let elen: u64 = 0u64;
if (n.rhs != nil) {
if (n.rhs.kind == nkind.N_INTLIT) { elen = n.rhs.uval; };
};
let sub: *tinfo = tinfofornode(c, n.lhs);
r = typearray(sub, elen);
} else { if (k == nkind.N_TFN) {
// Cstage cmd/wcc/check.c:437-466: function types are 8B / 8B
// (call-target pointer shape). Pre-bind before recursing into
// the return type so a recursive `type F = fn() F` self-ref
// doesn't spin (cycle-break mirror of the TSTRUCT/TTAGGED
// pattern below).
r = newtype(tykind.TY_FN);
r.size = 8u64;
r.align = 8u64;
r.slotsize = 8u64;
tinfocachebind(c.tc, n, r);
r.ret = tinfofornode(c, n.lhs);
} else { if (k == nkind.N_TENUM) {
// Cstage cmd/wcc/check.c:529-542: storage type's size/align
// (default i32 = 4B/4B). Cgen's slotsize-TENUM fallback pads
// to 8B per its stack-slot contract; tinfo.size carries the
// raw storage width so size(EnumT) folds to the correct value.
r = newtype(tykind.TY_ENUM);
let storage: *tinfo = nil;
if (n.lhs != nil) { storage = tinfofornode(c, n.lhs); };
if (storage == nil) { storage = c.tc.tyi32; };
r.sub = storage;
r.size = storage.size;
r.align = storage.align;
r.slotsize = storage.size;
} else { if (k == nkind.N_TTUPLE) {
// Cstage cmd/wcc/check.c:329-345: sum of element sizes with
// per-element alignment NOT padded — cstage uses raw sums for
// tuples and 8B-rounding lives at the call/return ABI layer.
// Pre-bind for cycle protection (recursive tuple shapes).
//
// #61 A.5: ti.size = natural sum (cstage parity); ti.slotsize
// = per-element slot sum mirroring cgenutil.ww:2018-2029
// slotsize TTUPLE — narrow scalars pad to 8 (cgen spills each
// tuple element into its own register / stack-slot eightbyte),
// composites contribute their own ti.slotsize.
r = newtype(tykind.TY_TUPLE);
tinfocachebind(c.tc, n, r);
// #57 A.6.3i-phase-1: populate r.tupleelems as a ttupleelem
// linked list (head=positional 0) in lock-step with the
// size/align accumulator. Harec analog ref/harec/src/type_
// store.c:532-589 tuple_init_from_atype — {type, offset, next}
// per member onto type->tuple.next chain. Diverges from cstage
// cmd/wcc/check.c:329-345 which stores tuple positionals on
// t->params (Tparam, no offset, consumer recomputes by walking
// at cgen.c:5723-5750); the offset-stored shape lets Phase
// 2/J consumers (dotchainresolve) read offsets directly per
// the A.6 stamp-once-read-many arc. Direct analog
// 26724fe (#50 phase 1, A.6.3f-a) for the head/tail append
// pattern. Offset matches cstage's raw-sum layout (no per-
// element padding) — rule 10 aligns wwstage tuple layout down
// to cstage, distinct from harec's add_padding(&offset,
// memb.align) at type_store.c:561.
let teh: *ttupleelem = nil;
let tet: *ttupleelem = nil;
let total: u64 = 0u64;
let slottotal: u64 = 0u64;
let maxal: u64 = 1u64;
let p: *node = n.list;
for (p != nil) {
let pt: *tinfo = tinfofornode(c, p.lhs);
let elemoff: u64 = total;
let te: *ttupleelem = alloc(ttupleelem{type_=pt, offset=elemoff, tnext=nil})!;
if (teh == nil) { teh = te; } else { tet.tnext = te; };
tet = te;
if (pt != nil) {
if (pt.align > maxal) { maxal = pt.align; };
total += pt.size;
slottotal += tupleelemslot(pt);
};
p = p.next;
};
r.tupleelems = teh;
r.size = total;
r.align = maxal;
r.slotsize = slottotal;
} else { if (k == nkind.N_TSTRUCT) {
// Cstage cmd/wcc/check.c:468-527: per-field alignment, max
// align for the whole record, total rounded up to alignment.
// Anonymous-embed promotion is deferred (#13).
//
// Pre-bind into the cache BEFORE walking fields so a
// self-referential pointer field (e.g., `next: *node` inside
// `type node = struct {..., next: *node, ...}`) terminates:
// the inner tinfofornode(TNAME(node)) resolvealias-recurses
// back to this same body node, hits the cache, and returns
// the in-progress stub. r.size is filled in below; the stub's
// only consumer during the recursion is typeptr (8B/8B
// regardless of pointee size), so partial-fill is safe.
//
// #61 A.5: alongside the natural layout (cstage parity), walk
// the same fields with the slot-padded sizing cgenutil.ww
// registerstruct uses (fieldsize → si.totsize for nested
// struct; size-derived alignment; final round to 8). That
// slot total lands in ti.slotsize so the cgen fast-path can
// graduate TY_STRUCT off the AST walker.
r = newtype(tykind.TY_STRUCT);
tinfocachebind(c.tc, n, r);
// #57 A.6.3i-phase-1: populate r.fields as a tfield linked
// list (head=first declared field) in lock-step with the
// natural-layout offset accumulator. Mirrors cstage cmd/wcc/
// check.c:468-527 (Tfield {name, type, offset, next} per
// member onto t->fields). Direct analog 26724fe (#50 phase 1,
// A.6.3f-a) for the head/tail append pattern. Harec cite:
// ref/harec/include/types.h:109-115 struct_field and
// ref/harec/src/type_store.c:314-347 struct_init_from_atype.
// Anonymous-embed promotion not populated here (#13 per
// the cstage cite at check.ww:1263).
let fh: *tfield = nil;
let ft_: *tfield = nil;
let off: u64 = 0u64;
let maxalign: u64 = 1u64;
let soff: u64 = 0u64;
let f: *node = n.list;
for (f != nil) {
if (f.kind == nkind.N_TFIELD) {
let ft: *tinfo = tinfofornode(c, f.lhs);
if (ft != nil) {
if (ft.align > maxalign) { maxalign = ft.align; };
if (ft.align > 0u64) {
off = (off + ft.align - 1u64) & ~(ft.align - 1u64);
};
let fldoff: u64 = off;
let tf: *tfield = alloc(tfield{name=f.str, type_=ft, offset=fldoff, tnext=nil})!;
if (fh == nil) { fh = tf; } else { ft_.tnext = tf; };
ft_ = tf;
off += ft.size;
// Slot-padded layout (mirror of cgenutil
// fieldsize + registerstruct align rules).
let fsz: u64 = fieldslotsize(ft);
let faln: u64 = 1u64;
if (fsz >= 8u64) { faln = 8u64; }
else { if (fsz >= 4u64) { faln = 4u64; }
else { if (fsz >= 2u64) { faln = 2u64; }; }; };
if ((soff & (faln - 1u64)) != 0u64) {
soff = (soff + faln - 1u64) & ~(faln - 1u64);
};
soff += fsz;
};
};
f = f.next;
};
r.fields = fh;
if (maxalign > 0u64) {
r.size = (off + maxalign - 1u64) & ~(maxalign - 1u64);
};
r.align = maxalign;
if ((soff & 7u64) != 0u64) {
soff = (soff + 7u64) & ~7u64;
};
r.slotsize = soff;
} else { if (k == nkind.N_TTAGGED) {
// Cstage cmd/wcc/check.c:347-435: 8B tag + max(variant)
// rounded up to 8. Pre-bind for cycle protection (recursive
// sum-type shapes through NAMED variants).
r = newtype(tykind.TY_TAGGED);
tinfocachebind(c.tc, n, r);
// #50 / A.6.3f phase 1: populate ti.params as a tparam linked
// list (head=first source variant). #61a: flatten `...inner`
// tagged spreads into the chain and stamp each variant's
// iserror. Mirrors cstage check.c:366-389 — dealias one NAMED
// level, require TY_TAGGED, splice its (already-flattened)
// variants in declaration order; otherwise append the single
// variant. size/align stays accounted off the surface member
// (vt), so r.size is byte-identical to pre-#61a: the flatten +
// iserror are additive, with no #61a-stage readers (the variant
// machinery + cgwidentaggedstore/matchscrutt migrate onto the
// chain in #61b/c). Same shared Tparam shape ww reuses across
// struct-fields / tuple-fields / fn-params / tagged-variants
// (sea-of-stars per rule 12). Phase 2 (#50b) retired cgenutil's
// AST-keyed nullableptrtag onto the chain.
let head: *tparam = nil;
let tail: *tparam = nil;
let maxsz: u64 = 0u64;
let al: u64 = 8u64;
let v: *node = n.list;
for (v != nil) {
let vt: *tinfo = tinfofornode(c, v);
if (vt != nil) {
if (vt.size > maxsz) { maxsz = vt.size; };
if (vt.align > al) { al = vt.align; };
};
let isspread: bool = (v.op == tkind.TK_ELLIPSIS);
let vu: *tinfo = vt;
if (isspread) {
if (vu != nil) {
if (vu.kind == tykind.TY_NAMED) { vu = vu.under; };
};
};
if (isspread && vu != nil && vu.kind == tykind.TY_TAGGED) {
// Spliced variants carry the inner union's
// already-stamped iserror; no re-derivation.
let src: *tparam = vu.params;
for (src != nil) {
let tp: *tparam = alloc(tparam{name="", type_=src.type_, iserror=src.iserror, tnext=nil})!;
if (head == nil) { head = tp; } else { tail.tnext = tp; };
tail = tp;
src = src.tnext;
};
} else {
let ve: bool = varianterr(c, v);
let tp: *tparam = alloc(tparam{name="", type_=vt, iserror=ve, tnext=nil})!;
if (head == nil) { head = tp; } else { tail.tnext = tp; };
tail = tp;
};
v = v.next;
};
r.params = head;
// #61 A.3 nullable fold: `(*T | void)` collapses to a single
// 8B pointer slot, null is the void variant. Mirrors
// cmd/wcc/check.c:412-426 — bare TNAME("void"), not `!void`,
// and not NAMED. AST-kind discrimination retained: wwstage
// tinfo carries no `iserror` field, so cstage's tinfo-level
// (kind==TY_VOID && !iserror) check doesn't port symmetrically.
let a: *node = n.list;
if (a != nil) {
let b: *node = a.next;
if (b != nil && b.next == nil) {
let aptr: bool = (a.kind == nkind.N_TPTR);
let bptr: bool = (b.kind == nkind.N_TPTR);
let avoid: bool = (a.kind == nkind.N_TNAME);
if (avoid) { avoid = streq(a.str, "void"); };
let bvoid: bool = (b.kind == nkind.N_TNAME);
if (bvoid) { bvoid = streq(b.str, "void"); };
let isnull: bool = false;
if (aptr) { if (bvoid) { isnull = true; }; };
if (avoid) { if (bptr) { isnull = true; }; };
if (isnull) {
r.size = 8u64;
r.align = 8u64;
r.nullable = 1;
r.slotsize = 8u64;
return r;
};
};
};
let pad: u64 = (maxsz + 7u64) & ~7u64;
r.size = 8u64 + pad;
r.align = al;
r.slotsize = 8u64 + pad;
};};};};};};};};};};};
if (r != nil) {
// #61 A.5: any arm that didn't set slotsize gets ti.size as
// the default (covers primitives via prim() + the ptr/slice/
// chan paths which already populate slotsize, plus TBANG which
// inherits the inner's tinfo unchanged).
if (r.slotsize == 0u64) { r.slotsize = r.size; };
tinfocachebind(c.tc, n, r);
};
return r;
};
// unifyarith — usual-arithmetic-conversion analogue at the AST-tnode
// layer. Mirrors cstage cmd/wcc/check.c:580-596 `unify_arith` and harec
// ref/harec/src/types.c type_promote. Trailing `return ltn` covers
// mismatched typed pairs; cstage flags the same shape — wwstage's
// checker stays silent here per existing discipline.
//
// Nil-on-valid classification (5-lite-b #34, A.6.2.1c #24): both ltn
// and rtn can be nil when an operand was an inherent-IDENT bail
// (exprtype N_IDENT arm L1596-1599 — SK_USE module ref or pseudo-
// builtin callee with sym.decl == nil; #19 retires these as
// dedicated AST kinds). Propagation, not silent gap — asserttyped
// gates those idents at the consumer layer.
fn unifyarith(c: *checker, ltn: *node, rtn: *node) *node = {
let lu: bool = isuntypedint(ltn) || isuntypedfloat(ltn);
let ru: bool = isuntypedint(rtn) || isuntypedfloat(rtn);
if (lu && ru) {
if (isuntypedfloat(ltn) || isuntypedfloat(rtn)) {
return mktname(c, "untyped_float");
};
return mktname(c, "untyped_int");
};
let conf: bool = false;
if (lu) {
if (isassignable(c, rtn, ltn, &conf)) { return rtn; };
};
if (ru) {
if (isassignable(c, ltn, rtn, &conf)) { return ltn; };
};
if (typeeqast(ltn, rtn)) { return ltn; };
// Mismatched typed pair — return ltn so the binop stamps something;
// 5-lite-b: the trailing nil-on-mismatch shape was eliminated when
// the helper was split out of binoptype.
return ltn;
};
// coercefloatlit — twin of cstage cmd/wcc/check.c coerce_floatlit (see there
// for the full rationale + the rule-10 scope note). Stamp an un-suffixed
// float literal (whose type_ is the untyped_float singleton) as f32 when the
// target type resolves to f32, so fold-1's cgen narrow (isf32type, cgenexpr.
// ww) fires off the now-f32 node.type_. SCOPED to a DIRECT untyped_float
// N_FLOATLIT at let-init / return only: the wwstage cgen's exprfloatkind
// (cgenutil.ww) hardcodes N_FLOATLIT -> f64 and cgbin / the unary negate pick
// f32 off the operands' float-kind, not the node stamp, so a stamped literal
// inside an arith-binop / behind a unary minus does NOT narrow there —
// binop / unary-minus / assign / call-arg / struct-field wait on #120.
fn coercefloatlit(c: *checker, e: *node, target: *node) void = {
if (e == nil) { return; };
if (target == nil) { return; };
let tu: *node = resolvealias(c, unwrapbang(target));
if (tu == nil) { return; };
if (tu.kind != nkind.N_TNAME) { return; };
if (!streq(tu.str, "f32")) { return; };
if (e.kind == nkind.N_FLOATLIT) {
if ((e.type_: *tinfo) == c.tc.tyuntypedfloat) {
let f32t: *node = mktname(c, "f32");
e.type_ = tinfofornode(c, f32t): *void;
};
};
};
// binoptype — derive the result tnode of an N_BIN operator expression.
// Mirrors cstage cmd/wcc/check.c:598-640 `cbinop`. Operates on tnodes
// returned by exprtype; ptr arithmetic / bitwise / shifts / comparisons /
// logicals all reflect cstage's rules. Type-mismatch diagnostics are
// elided here (cstage gates the same shape).
fn binoptype(c: *checker, e: *node) *node = {
let op: tkind = e.op;
let ltn: *node = exprtype(c, e.lhs, nil);
let rtn: *node = exprtype(c, e.rhs, nil);
if (op == tkind.TK_PLUS || op == tkind.TK_MINUS) {
if (ltn != nil && ltn.kind == nkind.N_TPTR && isinttypeast(rtn)) {
return ltn;
};
};
if (op == tkind.TK_PLUS) {
if (isinttypeast(ltn) && rtn != nil && rtn.kind == nkind.N_TPTR) {
return rtn;
};
};
if (op == tkind.TK_MINUS) {
if (ltn != nil && rtn != nil
&& ltn.kind == nkind.N_TPTR && rtn.kind == nkind.N_TPTR) {
return mktname(c, "i64");
};
};
if (op == tkind.TK_PLUS || op == tkind.TK_MINUS ||
op == tkind.TK_STAR || op == tkind.TK_SLASH ||
op == tkind.TK_PERCENT || op == tkind.TK_AMP ||
op == tkind.TK_PIPE || op == tkind.TK_CARET ||
op == tkind.TK_LSHIFT || op == tkind.TK_RSHIFT) {
return unifyarith(c, ltn, rtn);
};
if (op == tkind.TK_EQ || op == tkind.TK_NEQ ||
op == tkind.TK_LT || op == tkind.TK_LE ||
op == tkind.TK_GT || op == tkind.TK_GE ||
op == tkind.TK_AND || op == tkind.TK_OR) {
return mktname(c, "bool");
};
// Unreachable for valid input: op is one of TK_PLUS/MINUS/STAR/
// SLASH/PERCENT/AMP/PIPE/CARET/LSHIFT/RSHIFT/EQ/NEQ/LT/LE/GT/GE/
// AND/OR per parser invariant (lib/ww/parse/expr.ww binary-op
// table); all are handled above. 5-lite-b #34.
return nil;
};
// unoptype — derive the result tnode of an N_UN unary expression. Mirrors
// cstage cmd/wcc/check.c:642-687 `cunop` and harec ref/harec/src/types.c
// type_promote. The slice/str .len/.cap pseudo-field address-of widening
// to *i64 mirrors check.c:672-682 directly — its purpose is documented
// at the cstage site.
fn unoptype(c: *checker, e: *node) *node = {
let op: tkind = e.op;
let opt: *node = exprtype(c, e.lhs, nil);
if (op == tkind.TK_MINUS || op == tkind.TK_PLUS) { return opt; };
if (op == tkind.TK_NOT) { return mktname(c, "bool"); };
if (op == tkind.TK_TILDE) { return opt; };
if (op == tkind.TK_STAR) {
// opt nil here means the operand was an inherent-IDENT bail
// (exprtype N_IDENT arm L1596-1599 — SK_USE / pseudo-builtin
// sym.decl == nil — or another helper's nil propagation);
// 5-lite-b #34, A.6.2.1c #24. The `u == nil` post-resolvealias
// check was eliminated here — unwrapbang(non-nil) returns
// non-nil (parser invariant N_TBANG.lhs always set) and
// resolvealias passes through non-nil unchanged (L513
// `for (cur != nil)` only exits via `return cur` or `return n`).
if (opt == nil) { return nil; };
let u: *node = resolvealias(c, unwrapbang(opt));
// Invalid input (non-pointer dereference); cstage errors at
// cmd/wcc/check.c:660. 5-lite-b #34.
if (u.kind != nkind.N_TPTR) { return nil; };
return u.lhs;
};
if (op == tkind.TK_AMP) {
if (e.lhs != nil && e.lhs.kind == nkind.N_DOT) {
let fld: str = e.lhs.str;
if (streq(fld, "len") || streq(fld, "cap")) {
let base: *node = e.lhs.lhs;
if (base != nil && base.type_ != nil) {
let bu: *tinfo = base.type_: *tinfo;
if (bu != nil && bu.kind == tykind.TY_NAMED) { bu = bu.under; };
if (bu != nil && bu.kind == tykind.TY_PTR) { bu = bu.sub; };
if (bu != nil && bu.kind == tykind.TY_NAMED) { bu = bu.under; };
if (bu != nil) {
if (bu.kind == tykind.TY_SLICE || bu.kind == tykind.TY_STR) {
let pp: *node = newnode(nkind.N_TPTR, "", 0, 0);
pp.lhs = mktname(c, "i64");
return pp;
};
};
};
};
};
// opt nil → propagation from inherent-IDENT bail (5-lite-b
// #34). Generic &expr widens to *opt; without opt we can't
// synthesize the pointer node.
if (opt == nil) { return nil; };
let pp: *node = newnode(nkind.N_TPTR, "", 0, 0);
pp.lhs = opt;
return pp;
};
// Unreachable for valid input: op is one of TK_MINUS/PLUS/NOT/
// TILDE/STAR/AMP per parser invariant (lib/ww/parse/expr.ww unary
// op set); all are handled above. 5-lite-b #34.
return nil;
};
// indexresult — derive the result tnode of an N_INDEX expression.
// Mirrors cstage cmd/wcc/check.c:870-894 and harec ref/harec/src/types.c
// type_promote dispatch. Slice/array → elem; str → u8; `*[N]T` decays
// to T (pointer-to-array); `*[]T` does NOT decay (yields []T via the
// generic *U → U fallback — Hare-faithful, a pointer-to-slice is a 1D
// array of slices, not of T); generic *T → T.
fn indexresult(c: *checker, e: *node) *node = {
let basetn: *node = exprtype(c, e.lhs, nil);
let _idx: *node = exprtype(c, e.rhs, nil);
let u: *node = resolvealias(c, unwrapbang(basetn));
// basetn nil → propagation from inherent-IDENT bail at exprtype
// N_IDENT arm L1596-1599 (5-lite-b #34, A.6.2.1c #24).
// unwrapbang(nil)=nil and resolvealias(nil)=nil pass through.
if (u == nil) { return nil; };
if (u.kind == nkind.N_TSLICE) { return u.lhs; };
if (u.kind == nkind.N_TARRAY) { return u.lhs; };
if (u.kind == nkind.N_TNAME) {
if (streq(u.str, "str")) { return mktname(c, "u8"); };
};
if (u.kind == nkind.N_TPTR) {
let inner: *node = u.lhs;
let iu: *node = resolvealias(c, unwrapbang(inner));
if (iu != nil && iu.kind == nkind.N_TARRAY) {
return iu.lhs;
};
return inner;
};
// Invalid input (non-indexable base — cstage errors at
// cmd/wcc/check.c:893). 5-lite-b #34.
return nil;
};
// exprtype — best-effort type-AST inference for an expression
// node. Handles literals, identifiers, calls, casts, binary/unary
// ops, indexing, module-qualified refs + enum-member folds; returns
// nil for shapes we don't statically know (struct field access into
// non-primitive types, etc).
// `hint`: optional declared-type AST passed by the caller (let
// target, assign target). nil = "no hint, derive from self". Threaded
// for use by A.6.1's STRUCTLIT/ARRLIT arms which can't self-type and
// need the enclosing declared type to resolve. Ignored by every arm
// in A.6.0; the param is plumbed here so the per-kind work that
// follows doesn't ripple a fresh signature change. Mirrors harec's
// `check_expression(..., result_type, ...)` per
// `feedback_hare_frontend_reference.md`.
//
// Dispatcher invariant (5-lite-a #33): every value-producing nkind
// listed in resolvewalk's post-order dispatch (L474-489) reaches a
// stamping arm here that sets e.type_ before returning. No
// fall-through. Arms that return nil (binoptype trailing, unoptype
// TK_STAR opt-nil, indexresult u-nil, N_DOT outer fold-miss, N_SLICE
// non-sliceable base, etc.) are propagation from a callee's nil —
// not silent gaps. Mirror of harec's
// `assert(expr->result)` at ref/harec/src/check.c:3810. The
// asserttyped pass at L2871 enforces the invariant on every
// dispatched node post-checker, with gates for the residual
// inherent-IDENT bails (SK_USE, pseudo-builtin sym.decl==nil,
// N_DOT-LHS syntactic position, EXPR_ASSERT-family abort/assert) until
// #19 retires the bail shape.
fn exprtype(c: *checker, e: *node, hint: *node) *node = {
if (e == nil) { return nil; };
let k: nkind = e.kind;
// #61 audit §1.8 — A.2 widens A.1's single N_INTLIT population to
// every primitive literal arm + N_IDENT. Cgen size walkers
// (slotsize first; elemsize/fieldsize/letemitsize follow) consult
// node.type_ as the SSoT; populating literals + idents closes the
// loop from the read side.
if (k == nkind.N_INTLIT) {
// Typed-int literal (`7u32`, `0i8`): tsuffix names a builtin
// primitive. Mirrors cstage cmd/wcc/check.c:694-701 cexpr's
// `lookup_builtin(n->tsuffix)`; falls through to untyped_int
// when the suffix doesn't resolve.
if (e.tsuffix.len > 0) {
let suf: *node = mktname(c, e.tsuffix);
let ti: *tinfo = tinfofornode(c, suf);
if (ti != nil) {
e.type_ = ti: *void;
return suf;
};
};
let tn: *node = mktname(c, "untyped_int");
e.type_ = tinfofornode(c, tn): *void;
return tn;
};
if (k == nkind.N_FLOATLIT) {
// Typed-float literal (`1.5f32`, `0.0f64`): tsuffix names a
// builtin primitive. Mirrors cstage cmd/wcc/check.c:702-709
// cexpr's `lookup_builtin(n->tsuffix)`; falls through to
// untyped_float when the suffix doesn't resolve.
if (e.tsuffix.len > 0) {
let suf: *node = mktname(c, e.tsuffix);
let ti: *tinfo = tinfofornode(c, suf);
if (ti != nil) {
e.type_ = ti: *void;
return suf;
};
};
let tn: *node = mktname(c, "untyped_float");
e.type_ = tinfofornode(c, tn): *void;
return tn;
};
if (k == nkind.N_STRLIT) {
let tn: *node = mktname(c, "str");
e.type_ = tinfofornode(c, tn): *void;
return tn;
};
if (k == nkind.N_RUNELIT) {
let tn: *node = mktname(c, "rune");
e.type_ = tinfofornode(c, tn): *void;
return tn;
};
if (k == nkind.N_TRUE) {
let tn: *node = mktname(c, "bool");
e.type_ = tinfofornode(c, tn): *void;
return tn;
};
if (k == nkind.N_FALSE) {
let tn: *node = mktname(c, "bool");
e.type_ = tinfofornode(c, tn): *void;
return tn;
};
if (k == nkind.N_VOIDLIT) {
let tn: *node = mktname(c, "void");
e.type_ = tinfofornode(c, tn): *void;
return tn;
};
if (k == nkind.N_NIL) {
let tn: *node = mktname(c, "untyped_nil");
e.type_ = tinfofornode(c, tn): *void;
return tn;
};
if (k == nkind.N_IDENT) {
let s: *sym = scopelookup(c.cur, e.str);
if (s == nil) { return nil; };
if (s.decl == nil) { return nil; };
let t: *node = s.decl.lhs;
// Propagate the declared type's tinfo onto the use site so
// downstream cgen walkers can read n.type_ off an ident.
if (t != nil) {
if (t.type_ != nil) {
e.type_ = t.type_;
} else {
let ti: *tinfo = tinfofornode(c, t);
if (ti != nil) {
e.type_ = ti: *void;
t.type_ = ti: *void;
};
};
};
return t;
};
if (k == nkind.N_BIN) {
let tn: *node = binoptype(c, e);
e.type_ = tinfofornode(c, tn): *void;
return tn;
};
if (k == nkind.N_UN) {
let tn: *node = unoptype(c, e);
e.type_ = tinfofornode(c, tn): *void;
return tn;
};
if (k == nkind.N_INDEX) {
let tn: *node = indexresult(c, e);
e.type_ = tinfofornode(c, tn): *void;
return tn;
};
if (k == nkind.N_CAST) {
// `expr: T` — explicit cast; the type expr is e.rhs. Mirrors
// cstage cmd/wcc/check.c:737 `n->type = resolve_type(c, n->rhs)`.
e.type_ = tinfofornode(c, e.rhs): *void;
return e.rhs;
};
if (k == nkind.N_CALL) {
let callee: *node = e.lhs;
if (callee == nil) { return nil; };
// #31: synthesize the `alloc(value)` / `alloc([], n)` builtin
// return shape so checkletassign sees the same `(*T | nomem)` /
// `([]T | nomem)` cstage's check.c stamps at L981-1006. Without
// this, exprtype returns the seeded decl's nil lhs and the let
// silently accepts `let p: *T = alloc(v);` — rule 10 trap.
// Same-module gate mirrors cstage's `c->cur_mod &&
// scope_lookup_in_module(...)` check from task #23.
if (callee.kind == nkind.N_IDENT) {
if (streq(callee.str, "alloc")) {
let shadowed: bool = false;
if (c.curmod.len > 0) {
if (scopelookupinmodule(c.cur, c.curmod, "alloc") != nil) {
shadowed = true;
};
};
if (!shadowed) {
if (e.list != nil) {
// Slice form: `alloc([], n)`.
if (e.list.kind == nkind.N_ARRLIT) {
if (e.list.list == nil) {
if (e.list.next != nil) {
if (e.list.next.next == nil) {
let sl: *node = newnode(nkind.N_TSLICE, "", 0, 0);
sl.lhs = mktname(c, "u8");
let nome: *node = mktname(c, "nomem");
sl.next = nome;
let tt: *node = newnode(nkind.N_TTAGGED, "", 0, 0);
tt.list = sl;
e.type_ = tinfofornode(c, tt): *void;
return tt;
};
};
};
};
// Value form: `alloc(value)`.
if (e.list.next == nil) {
let argt: *node = exprtype(c, e.list, nil);
let ptr: *node = newnode(nkind.N_TPTR, "", 0, 0);
ptr.lhs = argt;
let nome: *node = mktname(c, "nomem");
ptr.next = nome;
let tt: *node = newnode(nkind.N_TTAGGED, "", 0, 0);
tt.list = ptr;
e.type_ = tinfofornode(c, tt): *void;
return tt;
};
};
};
};
};
// #42: size(T) / align(T) / offset(e.f) typed-builtin intercepts.
// Fold the N_CALL in place to an N_INTLIT so cgen never sees an
// unresolved size/align/offset symbol. Same-module shadow gate
// mirrors the alloc precedent (#23) so a user `fn size(...)`
// inside this module suppresses the builtin. Mirrors cstage
// cmd/wcc/check.c:907-960.
if (callee.kind == nkind.N_IDENT) {
let bname: str = callee.str;
let issize: bool = streq(bname, "size");
let isalign: bool = streq(bname, "align");
let isoffset: bool = streq(bname, "offset");
if (issize || isalign || isoffset) {
let shadowed: bool = false;
if (c.curmod.len > 0) {
if (scopelookupinmodule(c.cur, c.curmod, bname) != nil) {
shadowed = true;
};
};
if (!shadowed) {
if (e.list != nil) {
// Post-fold the node IS an N_INTLIT-shaped
// untyped_int constant. Mirrors cstage
// cmd/wcc/check.c:926/958 which stamps
// ty_untyped_int after the fold. The return
// tnode mktname("i32") is the assignability
// target for callers, not the constant's
// own type.
let utn: *node = mktname(c, "untyped_int");
if (issize) {
// #108(b): rule-10 twin of the cstage
// size/align unsized guard.
if (astunsized(c, e.list)) {
deffolderr(c, e, "cannot take size of unsized type 'opaque'");
};
let v: i64 = astsize(c, e.list);
foldtointlit(c, e, v);
e.type_ = tinfofornode(c, utn): *void;
return mktname(c, "i32");
};
if (isalign) {
if (astunsized(c, e.list)) {
deffolderr(c, e, "cannot take align of unsized type 'opaque'");
};
let v: i64 = astalign(c, e.list);
foldtointlit(c, e, v);
e.type_ = tinfofornode(c, utn): *void;
return mktname(c, "i32");
};
// offset(e.f): the arg is a value expression
// (N_DOT), parsed via parsearglist — not a
// type expression.
if (isoffset) {
if (e.list.next == nil && e.list.kind == nkind.N_DOT) {
let off: i64 = astoffset(c, e.list);
if (off < 0i64) {
os.write(2, "offset: no field '".ptr, 18u64);
os.write(2, e.list.str.ptr, e.list.str.len: u64);
os.write(2, "'\n".ptr, 2u64);
c.errs += 1;
off = 0i64;
};
foldtointlit(c, e, off);
e.type_ = tinfofornode(c, utn): *void;
return mktname(c, "i32");
};
};
};
};
};
};
// len(x) / append(s,...) / free(p) — Hare pseudo-builtins.
// Mirror cstage cmd/wcc/check.c:896-1011 (rule 10 requires
// stage byte-id; both stages stamp the same shape). No shadow
// guard: cstage's len/append/free intercepts have none either
// (check.c:901/962/1005), and the names are seeded into c.top
// at L85-88 so a user same-module decl dup-silences. Harec
// models these as dedicated AST kinds — EXPR_LEN at
// ref/harec/src/check.c:2630 (result `&builtin_type_size`),
// EXPR_APPEND at :745 (result `(nomem | void)`), EXPR_FREE at
// :2443 (result `&builtin_type_void`). The cstage divergence
// (len → i32 not size, append → void not tagged) pre-dates
// this task; #19 (Drew's δ — dedicated AST kinds) is the
// Hare-faithful path. This is the intercept-shim minimum to
// unblock #15 (A.6.2.1e assertion enable).
if (callee.kind == nkind.N_IDENT) {
if (streq(callee.str, "len")) {
let tn: *node = mktname(c, "i32");
e.type_ = tinfofornode(c, tn): *void;
return tn;
};
if (streq(callee.str, "append") || streq(callee.str, "free")) {
let tn: *node = mktname(c, "void");
e.type_ = tinfofornode(c, tn): *void;
return tn;
};
};
let nm: str;
nm.ptr = nil; nm.len = 0;
if (callee.kind == nkind.N_IDENT) { nm = callee.str; };
if (callee.kind == nkind.N_DOT) { nm = callee.str; };
// #56: bare-leaf N_IDENT calls go through scopelookupprefer so
// `foo()` inside module M binds to M.foo rather than another
// module's same-leaf foo at the head of the flat scope bucket.
// Mirrors cstage cexpr N_IDENT routing through
// scope_lookup_prefer with c->cur_mod.
//
// #6a-A: a module-qualified `mod.fn()` callee resolves via the
// callee.lhs module hint when `mod` is an import (SK_USE) —
// scopelookupinmodule(mod, leaf) — mirroring cstage cexpr N_DOT
// (cmd/wcc/check.c:1035 scope_lookup_in_module) and cgen's
// rettupleof (cgen.ww:2263 fnretlookupmod). Closing this at the
// N_CALL root (vs the N_MLET backfill) makes every consumer of a
// module-qual call result — destructure binding AND a bare
// `mod.fn().0` rvalue — read the right return type via the one
// expr path, harec-faithful (binding-unpack does zero callee
// resolution, ref/harec/src/check.c:1354-1419). Without it the
// bare-leaf scopelookup grabbed whichever same-leaf fn heads the
// flat scope — wrong on a cross-module shadow (753_convwrap_audit:
// alpha.foo (i64,str) vs beta.foo (i64,i64)).
//
// #6a-D: a D-class callee whose `mod` leaf is itself a type/fn
// (SK_TYPE/SK_FN — random.random / fnmatch.fnmatch collision)
// resolves through scopelookupprefer to that same-leaf entry, not
// the coexisting SK_USE, when curmod matches the colliding decl's
// package — so the SK_USE gate below misses and the call stays
// nil-stamped. scopelookupuselocal re-resolves `mod` to the SK_USE
// that coexists in the same scope (coexistence-equivalent of
// cstage's use_alias; see lib/ww/sym.ww + memory
// module_type_name_collision).
//
// #181: a non-named callee (N_UN TK_STAR deref of a *fn local,
// `(*f)(...)`; or any other expression-as-callee shape) has no
// leaf to resolve here — skip the SK_FN name-lookup and let the
// fn-VALUE fallback below peel TPTR / dealias to TFN. Mirrors
// harec check_autodereference at ref/harec/src/check.c:1566.
// cgen post-#180+#185 already lowers the deref-call correctly,
// so lifting the asserttyped bail is silent-SIGSEGV-safe.
if (nm.len > 0) {
let s: *sym = nil;
if (callee.kind == nkind.N_IDENT) {
s = scopelookupprefer(c.cur, c.curmod, nm);
} else {
let ms: *sym = nil;
if (callee.lhs != nil && callee.lhs.kind == nkind.N_IDENT) {
ms = scopelookupprefer(c.cur, c.curmod, callee.lhs.str);
if (ms != nil && ms.skind != skind.SK_USE) {
let mu: *sym = scopelookupuselocal(ms.scope, callee.lhs.str);
if (mu != nil) { ms = mu; };
};
};
if (ms != nil && ms.skind == skind.SK_USE) {
s = scopelookupinmodule(c.cur, callee.lhs.str, nm);
} else {
s = scopelookup(c.cur, nm);
};
};
if (s != nil) { if (s.skind == skind.SK_FN) { if (s.decl != nil) {
// fn-decl's lhs is the return-type AST node. Mirrors cstage
// cmd/wcc/check.c:984+ regular-CALL `n->type =
// build_fn_type(c, s->decl)->ret` shape.
e.type_ = tinfofornode(c, s.decl.lhs): *void;
return s.decl.lhs;
}; }; };
};
// A callee that is a fn-VALUE — a fn-pointer struct field
// (`w.emit(...)`), local, or param — has no free SK_FN entry, so
// the name lookup above misses. Read the result off the checked
// callee node's own type instead: autodereference + dealias to
// the TY_FN, then take its result. Mirrors harec's check_expr_call
// `expr->result = type_dealias(check_autodereference(lvalue->
// result))->func.result` (ref/harec/src/check.c:1566-1581). The
// name path stays primary because a fn-NAME callee node in wwstage
// already carries its RETURN type (fn-decl.lhs), not its fn-type —
// so a `fn make() fn() void` callee would otherwise mis-yield void.
let ct: *node = resolvealias(c, unwrapbang(exprtype(c, callee, nil)));
for (ct != nil && ct.kind == nkind.N_TPTR) {
ct = resolvealias(c, unwrapbang(ct.lhs));
};
if (ct != nil) { if (ct.kind == nkind.N_TFN) {
let res: *node = ct.lhs;
e.type_ = tinfofornode(c, res): *void;
return res;
}; };
return nil;
};
if (k == nkind.N_DOT) {
// A.6.1.5a — fold cases only. Mirrors cstage cmd/wcc/check.c
// :740-832. Struct field + pseudo-field (.len/.cap/.ptr) lands
// in A.6.1.5b. SK_USE gates case 1; a #6a-D dot-lhs collision
// (random.random / fnmatch.fnmatch — the module leaf is also a
// same-scope type/fn) re-resolves through scopelookupuselocal so
// the SK_USE coexisting alongside the type/fn wins (the
// coexistence-equivalent of cstage's use_alias; see installdecl
// docstring + lib/ww/sym.ww). Enum-member fold delegates
// non-literal lhs shapes (sibling backref, unary, binary, shift)
// to enumvalfold, matching cstage cmd/wcc/check.c:210-284 and
// harec's enum-resolve constexpr set at
// ref/harec/src/check.c:4419-4434.
let lhsn: *node = e.lhs;
if (lhsn != nil) { if (lhsn.kind == nkind.N_IDENT) {
let ms: *sym = scopelookupprefer(c.cur, c.curmod, lhsn.str);
if (ms != nil && ms.skind != skind.SK_USE) {
let mu: *sym = scopelookupuselocal(ms.scope, lhsn.str);
if (mu != nil) { ms = mu; };
};
if (ms != nil) {
// Fold case 1: module-qualified ref. Mirror cstage
// check.c:749-775. cstage returns ty_err on SK_USE
// with missing leaf (extern decl); wwstage falls
// through to outer case — cgen has its own module-
// qualified resolution and the lenient checker policy
// keeps the silent miss documented at scruttype L656.
if (ms.skind == skind.SK_USE) {
let fs: *sym = scopelookupinmodule(c.cur, lhsn.str, e.str);
if (fs != nil) { if (fs.decl != nil) {
let tn: *node = fs.decl.lhs;
if (tn != nil) {
e.type_ = tinfofornode(c, tn): *void;
return tn;
};
}; };
};
// Fold case 2 inner: bare `EnumT.MEMBER` where EnumT
// is an SK_TYPE in the flat scope. Mirror cstage
// check.c:780-803.
if (ms.skind == skind.SK_TYPE) { if (ms.decl != nil) {
let body: *node = ms.decl.lhs;
let ub: *node = resolvealias(c, unwrapbang(body));
if (ub != nil) { if (ub.kind == nkind.N_TENUM) {
let prev: u64 = (-1i64): u64;
let m: *node = ub.list;
for (m != nil) {
let val: u64 = 0u64;
if (m.lhs == nil) {
val = prev + 1u64;
} else {
if (!enumvalfold(ub, m, m.lhs, &val)) { return nil; };
};
prev = val;
if (streq(m.str, e.str)) {
foldtointlit(c, e, val: i64);
e.type_ = tinfofornode(c, body): *void;
return body;
};
m = m.next;
};
}; };
}; };
};
}; };
// Fold case 2 outer: base resolves to enum, e.g.
// `pkg.EnumT.MEMBER` where the inner N_DOT (pkg.EnumT) folded
// via case 1 above to the enum body. Mirror cstage
// check.c:805-832. Peel one TPTR for `(*EnumT).MEMBER` (rare
// but cstage handles it at L808).
let basetn: *node = exprtype(c, lhsn, nil);
if (basetn != nil) {
let bu: *node = resolvealias(c, unwrapbang(basetn));
if (bu != nil) { if (bu.kind == nkind.N_TPTR) {
bu = resolvealias(c, unwrapbang(bu.lhs));
}; };
if (bu != nil) { if (bu.kind == nkind.N_TENUM) {
let prev: u64 = (-1i64): u64;
let m: *node = bu.list;
for (m != nil) {
let val: u64 = 0u64;
if (m.lhs == nil) {
val = prev + 1u64;
} else {
if (!enumvalfold(bu, m, m.lhs, &val)) { return nil; };
};
prev = val;
if (streq(m.str, e.str)) {
foldtointlit(c, e, val: i64);
e.type_ = tinfofornode(c, basetn): *void;
return basetn;
};
m = m.next;
};
}; };
// A.6.1.5b stamp cases — mirror cstage check.c:833-866. Pure
// type-AST stamps; never rewrite e.kind. Lenient on misses
// (cstage errors); falls through to nil under scruttype L656.
//
// Pseudo-fields .len/.cap/.ptr on slice/str/array. Cstage
// L833-842. `str` lives as N_TNAME("str") in wwstage — no
// dedicated N_TSTR kind — so test the trio shape here.
if (bu != nil) {
let isstr: bool = (bu.kind == nkind.N_TNAME) && streq(bu.str, "str");
if (bu.kind == nkind.N_TSLICE || bu.kind == nkind.N_TARRAY || isstr) {
if (streq(e.str, "len")) {
let tn: *node = mktname(c, "i32");
e.type_ = tinfofornode(c, tn): *void;
return tn;
};
if (streq(e.str, "cap")) {
let tn: *node = mktname(c, "i32");
e.type_ = tinfofornode(c, tn): *void;
return tn;
};
if (streq(e.str, "ptr")) {
let elem: *node = bu.lhs;
if (isstr) { elem = mktname(c, "u8"); };
let pp: *node = newnode(nkind.N_TPTR, "", 0, 0);
pp.lhs = elem;
e.type_ = tinfofornode(c, pp): *void;
return pp;
};
};
};
// Struct field walk. Cstage L843-849 errors on missing field.
if (bu != nil) { if (bu.kind == nkind.N_TSTRUCT) {
let f: *node = bu.list;
for (f != nil) {
if (f.kind == nkind.N_TFIELD) { if (streq(f.str, e.str)) {
e.type_ = tinfofornode(c, f.lhs): *void;
return f.lhs;
}; };
f = f.next;
};
}; };
// Tuple positional access `t.0`, `t.1`, …. Cstage L850-866
// errors on non-numeric / out-of-range; wwstage falls
// through. fldnumidx (cgenutil) returns -1 on non-digit.
if (bu != nil) { if (bu.kind == nkind.N_TTUPLE) {
let idx: i32 = fldnumidx(e.str);
if (idx >= 0) {
let p: *node = bu.list;
for (idx > 0 && p != nil) {
p = p.next;
idx -= 1;
};
if (p != nil) {
let pt: *node = p.lhs;
e.type_ = tinfofornode(c, pt): *void;
return pt;
};
};
}; };
};
return nil;
};
if (k == nkind.N_STRUCTLIT) {
// A.6.1.6 — head-only stamp of the struct-lit's overall type.
// Mirror cstage cmd/wcc/check.c:1161-1197; field-level walk
// (cstage L1178-1194) parked behind #23 / Phase 2 — field
// values are walked by the post-order exprtype dispatch at
// L460-489, so each field expr still gets its own n.type_.
//
// Parser at lib/ww/parse/expr.ww:147-148 always plants the
// TYPE_IDENT in e.lhs; e.lhs == nil would be a future Hare-
// style anonymous struct lit we don't yet parse — bail.
if (e.lhs == nil) { return nil; };
if (e.lhs.kind == nkind.N_IDENT) {
let ms: *sym = scopelookupprefer(c.cur, c.curmod, e.lhs.str);
if (ms != nil) { if (ms.skind == skind.SK_TYPE) { if (ms.decl != nil) {
let tn: *node = ms.decl.lhs;
if (tn != nil) {
// #66 Phase-N step 3: stamp e.type_ to the NOMINAL
// per-decl NAMED, not the flattened body. `overflow{}`
// where `type overflow = !void` must carry
// NAMED(overflow) so the typeeq variant match
// (cgenutil flatvariantidx) selects the overflow arm
// instead of falling to the scalar shape fallback;
// stamping tinfofornode(tn) gave the body (TY_VOID)
// and lost nominal identity. Resolve through a
// synthesized TNAME to reuse tinfofornode's TY_NAMED
// build/cache (check.ww:1157) — the SAME NAMED ptr
// the union variant resolved to. Mirrors cstage
// resolving overflow{} to the overflow Type, and ww's
// own N_CAST / N_IDENT arms which already stamp NAMED.
// Return the body node tn unchanged: byte-id rides
// e.type_ (cgen), while the checker's AST-level
// assign/return checks keep their prior input.
let tnm: *node = mktname(c, e.lhs.str);
let nti: *tinfo = tinfofornode(c, tnm);
if (nti != nil) { e.type_ = nti: *void; }
else { e.type_ = tinfofornode(c, tn): *void; };
return tn;
};
}; }; };
// Lenient on miss: cstage L1170 errors, wwstage falls
// through (scruttype L656 / A.6.1.5b N_DOT struct-miss).
return nil;
};
// Synthetic type-expr (`(*T){...}` etc). Mirror cstage L1175
// resolve_type(c, n->lhs).
e.type_ = tinfofornode(c, e.lhs): *void;
return e.lhs;
};
if (k == nkind.N_ARRLIT) {
// A.6.1.7 — head-only stamp of the array-lit's overall type.
// Mirror cstage cmd/wcc/check.c:1198-1211: walk elements,
// skip the `...` repeat sentinel (parse/expr.ww:101-105),
// first-element-wins for the elem type, count non-skipped
// elements, synthesize an N_TARRAY{elt, INTLIT count}. Empty
// list defaults to `[0]i32` per cstage L1209. Per-element
// stamps still fire via the post-order dispatch at L460-489
// (N_ARRLIT is in the kind list since A.6.0); the re-walk in
// the loop below is tinfocache-idempotent (L467).
//
// Documented cstage divergence: cstage L1206 applies
// type_default to lift untyped_int → i32 etc; wwstage stamps
// the raw exprtype result, matching the alloc-value-form
// precedent at L1509. Consumers default-type via the declared
// `let` slot until A.6.3 lands. Mixed-type elements follow
// cstage first-element-wins; no unify check (future scope).
let elt: *node = nil;
let count: u64 = 0u64;
let it: *node = e.list;
for (it != nil) {
let skip: bool = false;
if (it.kind == nkind.N_FIELD) {
if (streq(it.str, "...")) { skip = true; };
};
if (!skip) {
let t: *node = exprtype(c, it, nil);
if (elt == nil) { elt = t; };
count += 1u64;
};
it = it.next;
};
if (elt == nil) { elt = mktname(c, "i32"); };
let arr: *node = newnode(nkind.N_TARRAY, "", 0, 0);
arr.lhs = elt;
let cn: *node = newnode(nkind.N_INTLIT, "", 0, 0);
cn.uval = count;
arr.rhs = cn;
e.type_ = tinfofornode(c, arr): *void;
return arr;
};
if (k == nkind.N_SLICE) {
// A.6.2.0a — head-only stamp of the slice expression's overall
// type. Mirrors cstage cmd/wcc/check.c:1214-1228 N_SLICE: peel
// alias on the base; [N]T → []T, []T → []T (return base), str
// → str, *T (non-nil sub) → []T. Slice bounds (e.rhs start,
// e.cond end) are already covered by the post-order dispatch
// at L460-489 (typically N_INTLIT/N_IDENT/N_BIN, all in the
// dispatch list), so we do not double-walk them here.
// Documented cstage divergence: cstage L1227 errors on a
// non-sliceable base; wwstage returns nil (lenient on miss),
// matching scruttype L656 / A.6.1.5b N_DOT precedent.
let basetn: *node = exprtype(c, e.lhs, nil);
let bu: *node = resolvealias(c, unwrapbang(basetn));
if (bu == nil) { return nil; };
if (bu.kind == nkind.N_TARRAY) {
let sl: *node = newnode(nkind.N_TSLICE, "", 0, 0);
sl.lhs = bu.lhs;
e.type_ = tinfofornode(c, sl): *void;
return sl;
};
if (bu.kind == nkind.N_TSLICE) {
e.type_ = tinfofornode(c, basetn): *void;
return basetn;
};
if (bu.kind == nkind.N_TNAME) {
if (streq(bu.str, "str")) {
let tn: *node = mktname(c, "str");
e.type_ = tinfofornode(c, tn): *void;
return tn;
};
};
if (bu.kind == nkind.N_TPTR && bu.lhs != nil) {
let sl: *node = newnode(nkind.N_TSLICE, "", 0, 0);
sl.lhs = bu.lhs;
e.type_ = tinfofornode(c, sl): *void;
return sl;
};
return nil;
};
if (k == nkind.N_TUPLE) {
// A.6.2.0b — head-only stamp of the tuple expression's
// overall type. Mirrors cstage cmd/wcc/check.c:1437-1451
// N_TUPLE: walk e.list, type each element via exprtype, and
// assemble an N_TTUPLE whose .list chains N_TPARAM wrappers
// (one per element) so shared element-type ASTs (sym.decl.lhs,
// another tuple's element, struct field's .lhs) keep their
// own .next untouched — see lib/ww/ast.ww:101 and the
// A.6.2.0b-pre parser precedent at lib/ww/parse/parse.ww:302.
// Per-element exprtype recursion is tinfocache-idempotent
// (resolvewalk L460-489 already dispatches into N_TUPLE
// children). Lenient on empty list: grammar requires >= 2
// elements (lib/ww/parse/expr.ww:117 single-elem returns the
// expression), so empty is unreachable and yields nil here
// (matches scruttype L656 / A.6.1.5b N_DOT lenient-on-miss).
if (e.list == nil) { return nil; };
let head: *node = nil;
let tail: *node = nil;
let it: *node = e.list;
for (it != nil) {
let elemt: *node = exprtype(c, it, nil);
let w: *node = newnode(nkind.N_TPARAM, "", 0, 0);
w.lhs = elemt;
if (head == nil) { head = w; }
else { tail.next = w; };
tail = w;
it = it.next;
};
let tt: *node = newnode(nkind.N_TTUPLE, "", 0, 0);
tt.list = head;
e.type_ = tinfofornode(c, tt): *void;
return tt;
};
if (k == nkind.N_RECV) {
// A.6.2.0d — head-only stamp of the receive expression's
// overall type. Mirrors cstage cmd/wcc/check.c:1230-1236
// N_RECV: peel alias on the channel base; chan T → T.
// Documented cstage divergence: cstage L1234 errors on a
// non-chan base; wwstage returns nil (lenient on miss),
// matching scruttype L656 / A.6.1.5b N_DOT precedent.
let basetn: *node = exprtype(c, e.lhs, nil);
let bu: *node = resolvealias(c, unwrapbang(basetn));
if (bu == nil) { return nil; };
if (bu.kind == nkind.N_TCHAN) {
e.type_ = tinfofornode(c, bu.lhs): *void;
return bu.lhs;
};
return nil;
};
if (k == nkind.N_SPREAD) {
// A.6.2.0e — pass-through stamp. Mirrors cstage check.c:1212-1213.
// The spread expression `xs...` carries the operand's type.
let t: *node = exprtype(c, e.lhs, nil);
if (t != nil) { e.type_ = tinfofornode(c, t): *void; };
return t;
};
if (k == nkind.N_MATCH) {
// A.6.2.0g — port of cstage cmd/wcc/check.c:1316-1330 match-as-
// expression stamp. The match's type is the first arm's yield
// operand type; void if no arm yields. Wwstage skips cstage's
// arm-yield-unification check (L1322-1327) — that's a checker
// concern, this arm only stamps. Closes the consumer half of
// the match-as-expression contract that A.6.2.0f opened on the
// producer side (N_YIELD).
let yt: *node = nil;
let cs: *node = e.list;
for (cs != nil) {
let t: *node = matchyieldtype(c, cs.body);
if (t != nil) { yt = t; break; };
cs = cs.next;
};
if (yt == nil) {
yt = mktname(c, "void");
};
e.type_ = tinfofornode(c, yt): *void;
return yt;
};
if (k == nkind.N_YIELD) {
// A.6.2.0f — pass-through stamp; cstage check.c:1708 does NOT
// stamp N_YIELD (statement-shaped). Wwstage's A.6.2 invariant
// requires every post-dispatch kind have type_ set. Yield's
// value type is the operand's type per Hare's unified stmt/expr
// AST (ref/hare/hare/ast/expr.ha:449-461 — yield_expr is an
// expression with a type). Bare `yield;` (no operand) stamps
// void.
if (e.lhs == nil) {
let v: *node = mktname(c, "void");
e.type_ = tinfofornode(c, v): *void;
return v;
};
let t: *node = exprtype(c, e.lhs, nil);
if (t != nil) { e.type_ = tinfofornode(c, t): *void; };
return t;
};
if (k == nkind.N_TRYPROP) {
// success unwrap: the success-variant type of operand's
// tagged union.
let opt: *node = exprtype(c, e.lhs, nil);
let ou: *node = resolvealias(c, unwrapbang(opt));
if (ou == nil) { return nil; };
if (ou.kind != nkind.N_TTAGGED) { return nil; };
// Hare semantics: success = first non-error variant if
// any !-flag is present; else first variant.
if (taggedhaserr(c, ou)) {
let v: *node = ou.list;
for (v != nil) {
if (!iserrvariant(c, ou, v)) {
e.type_ = tinfofornode(c, v): *void;
return v;
};
v = v.next;
};
return nil;
};
e.type_ = tinfofornode(c, ou.list): *void;
return ou.list;
};
if (k == nkind.N_TRYUNW) {
// `e!` abort-on-error unwrap; success variant is what the
// receiver gets, identical to `?` shape modulo control flow.
// #31: required so `let p: *T = alloc(v)!;` resolves to *T.
let opt: *node = exprtype(c, e.lhs, nil);
let ou: *node = resolvealias(c, unwrapbang(opt));
if (ou == nil) { return nil; };
if (ou.kind != nkind.N_TTAGGED) { return nil; };
if (taggedhaserr(c, ou)) {
let v: *node = ou.list;
for (v != nil) {
if (!iserrvariant(c, ou, v)) {
e.type_ = tinfofornode(c, v): *void;
return v;
};
v = v.next;
};
return nil;
};
e.type_ = tinfofornode(c, ou.list): *void;
return ou.list;
};
if (k == nkind.N_TYPEASSERT) {
// `e as T` → T. Mirrors cstage cmd/wcc/check.c TYPEASSERT
// `n->type = resolve_type(c, n->rhs)`.
e.type_ = tinfofornode(c, e.rhs): *void;
return e.rhs;
};
if (k == nkind.N_TYPETEST) {
// `e is T` → bool
let tn: *node = mktname(c, "bool");
e.type_ = tinfofornode(c, tn): *void;
return tn;
};
return nil;
};
// isuntypedint / is_str_like / is_bool_like — helpers used
// by the assignability check below to allow common AST shapes
// through without needing real type inference.
fn isuntypedint(t: *node) bool = {
if (t == nil) { return false; };
if (t.kind != nkind.N_TNAME) { return false; };
return streq(t.str, "untyped_int");
};
fn isuntypedfloat(t: *node) bool = {
if (t == nil) { return false; };
if (t.kind != nkind.N_TNAME) { return false; };
return streq(t.str, "untyped_float");
};
fn isuntypednil(t: *node) bool = {
if (t == nil) { return false; };
if (t.kind != nkind.N_TNAME) { return false; };
return streq(t.str, "untyped_nil");
};
// isinttypeast — int-typed AST node. Either a primitive int name
// (i8..i64/u8..u64/int/uint/uintptr/rune) or an N_TENUM. Floats are
// excluded so the enum↔int reinterpret in checkisas (#52) refuses a
// surprise `enum as f64` shape. Mirrors cstage's type_isint
// (cmd/wcc/type.c) restricted to the kinds reachable from AST.
fn isinttypeast(t: *node) bool = {
if (t == nil) { return false; };
if (t.kind == nkind.N_TENUM) { return true; };
if (t.kind != nkind.N_TNAME) { return false; };
let s: str = t.str;
if (streq(s, "i8")) { return true; };
if (streq(s, "i16")) { return true; };
if (streq(s, "i32")) { return true; };
if (streq(s, "i64")) { return true; };
if (streq(s, "u8")) { return true; };
if (streq(s, "u16")) { return true; };
if (streq(s, "u32")) { return true; };
if (streq(s, "u64")) { return true; };
if (streq(s, "int")) { return true; };
if (streq(s, "uint")) { return true; };
if (streq(s, "uintptr")) { return true; };
if (streq(s, "size")) { return true; };
if (streq(s, "rune")) { return true; };
return false;
};
fn isnumerictname(t: *node) bool = {
if (t == nil) { return false; };
if (t.kind != nkind.N_TNAME) { return false; };
let s: str = t.str;
if (streq(s, "i8")) { return true; };
if (streq(s, "i16")) { return true; };
if (streq(s, "i32")) { return true; };
if (streq(s, "i64")) { return true; };
if (streq(s, "u8")) { return true; };
if (streq(s, "u16")) { return true; };
if (streq(s, "u32")) { return true; };
if (streq(s, "u64")) { return true; };
if (streq(s, "int")) { return true; };
if (streq(s, "uint")) { return true; };
if (streq(s, "uintptr")) { return true; };
if (streq(s, "size")) { return true; };
if (streq(s, "rune")) { return true; };
if (streq(s, "f32")) { return true; };
if (streq(s, "f64")) { return true; };
return false;
};
fn isstrtname(t: *node) bool = {
if (t == nil) { return false; };
if (t.kind != nkind.N_TNAME) { return false; };
return streq(t.str, "str");
};
// isassignable — AST-level approximation of C check.c
// type_assignable. Returns true when we know the assignment is
// OK, false only when we're confident it isn't, and "skip" (true)
// when we can't tell — to avoid false positives. The trailing bool
// `confident` lets the caller decide whether to emit an error
// when the result is false: if !confident, the caller should not
// flag it.
fn isassignable(c: *checker, dst: *node, src: *node, confident: *bool) bool = {
*confident = false;
if (dst == nil) { return true; }; // no declared target
if (src == nil) { return true; }; // unknown src type
*confident = true;
let du: *node = resolvealias(c, unwrapbang(dst));
let su: *node = resolvealias(c, unwrapbang(src));
if (du == nil) { *confident = false; return true; };
if (su == nil) { *confident = false; return true; };
if (typeeqast(du, su)) { return true; };
// untyped numeric → any numeric named type.
if (isuntypedint(su)) {
if (isnumerictname(du)) { return true; };
// (T | ...) tagged: only OK if some variant accepts untyped_int.
if (du.kind == nkind.N_TTAGGED) {
let v: *node = du.list;
for (v != nil) {
let vu: *node = resolvealias(c, unwrapbang(v));
if (vu != nil) {
if (isnumerictname(vu)) { return true; };
};
v = v.next;
};
*confident = false;
return true;
};
// Known non-numeric primitive: confidently wrong.
if (du.kind == nkind.N_TNAME) {
if (streq(du.str, "bool")) { return false; };
if (streq(du.str, "void")) { return false; };
if (streq(du.str, "str")) { return false; };
};
// Unknown shapes: stay quiet.
*confident = false;
return true;
};
if (isuntypedfloat(su)) {
if (isnumerictname(du)) { return true; };
if (du.kind == nkind.N_TNAME) {
if (streq(du.str, "bool")) { return false; };
if (streq(du.str, "void")) { return false; };
if (streq(du.str, "str")) { return false; };
};
*confident = false;
return true;
};
if (isuntypednil(su)) {
// nil → ptr/slice/chan/fn/nullable
if (du.kind == nkind.N_TPTR) { return true; };
if (du.kind == nkind.N_TSLICE) { return true; };
if (du.kind == nkind.N_TCHAN) { return true; };
if (du.kind == nkind.N_TFN) { return true; };
// nullable `(*T | void)` — already accepted by typeeqast
// when matched whole; nil is OK there too.
if (du.kind == nkind.N_TTAGGED) {
let v: *node = du.list;
for (v != nil) {
if (v.kind == nkind.N_TPTR) { return true; };
if (v.kind == nkind.N_TSLICE){ return true; };
v = v.next;
};
};
*confident = false;
return true;
};
// Tagged-union variant inclusion: src is one of dst's variants.
// Recursive isassignable mirrors cstage type_assignable
// (cmd/wcc/type.c:298-299) and harec tagged_select_subtype's
// recursive type_is_assignable call (ref/harec/src/types.c:702-739,
// :718; invoked from the TAGGED arm at :1110-1112). #39 cascade:
// the prior typeeqast-only walk rejected widenings that aren't
// strict surface-eq (NAMED-aliased variants, nested tagged inside
// a variant, concrete → variant after the wrap-induced exprtype
// reshape). #55 surface-nominal fast path is preserved by the
// recursive call's leading typeeqast (line 2257). #57 bare-vs-
// qualified TNAME residual unchanged.
if (du.kind == nkind.N_TTAGGED && su.kind != nkind.N_TTAGGED) {
let v: *node = du.list;
for (v != nil) {
let innerconf: bool = false;
if (isassignable(c, v, src, &innerconf)) { return true; };
v = v.next;
};
return false;
};
// tagged → tagged: structural variant list compare. Skip
// (don't be confident) — common when forwarding a fallible
// return through another fn with the same shape but possibly
// a different surface spelling.
if (du.kind == nkind.N_TTAGGED && su.kind == nkind.N_TTAGGED) {
*confident = false;
return true;
};
// tagged → non-tagged: requires `?` / `!` / match to project a
// variant. #31: this is what traps `let p: *T = alloc(v);`
// where the builtin returns `(*T | nomem)` and the LHS is bare.
if (su.kind == nkind.N_TTAGGED && du.kind != nkind.N_TTAGGED) {
return false;
};
// Two known primitives with different names are confidently
// incompatible. `i32 ↔ bool`, `str ↔ i32`, etc.
if (du.kind == nkind.N_TNAME && su.kind == nkind.N_TNAME) {
let known_d: bool = isnumerictname(du) || isstrtname(du);
if (!known_d) { if (streq(du.str, "bool")) { known_d = true; }; };
if (!known_d) { if (streq(du.str, "void")) { known_d = true; }; };
let known_s: bool = isnumerictname(su) || isstrtname(su);
if (!known_s) { if (streq(su.str, "bool")) { known_s = true; }; };
if (!known_s) { if (streq(su.str, "void")) { known_s = true; }; };
if (known_d) {
if (known_s) {
// Both primitives, different names → no.
return false;
};
};
};
// Anything else: don't claim confidence.
*confident = false;
return true;
};
// ---- match exhaustiveness --------------------------------------------
//
// For every match arm, verify that every variant of the scrutinee's
// tagged-union type is handled by some case (or a default arm
// exists). Multi-pattern `case A | B =>` covers all alts.
fn casecovers(c: *checker, cs: *node, want: *node) bool = {
if (cs.lhs != nil) {
if (typeeqast(cs.lhs, want)) { return true; };
};
let alt: *node = cs.list;
for (alt != nil) {
if (typeeqast(alt, want)) { return true; };
alt = alt.next;
};
return false;
};
fn errmatchvariant(c: *checker, n: *node, vname: *node) void = {
os.write(2, "match: variant not handled".ptr, 26u64);
if (vname != nil) {
if (vname.kind == nkind.N_TNAME) {
os.write(2, " (".ptr, 2u64);
os.write(2, vname.str.ptr, vname.str.len: u64);
os.write(2, ")".ptr, 1u64);
};
};
os.write(2, "\n".ptr, 1u64);
c.errs += 1;
};
// casevariantin — true iff `pat` (a `case T` pattern, including
// each alt of a multi-pattern) names a variant of the tagged
// union `tagged`.
fn casevariantin(tagged: *node, pat: *node) bool = {
let v: *node = tagged.list;
for (v != nil) {
if (typeeqast(v, pat)) { return true; };
v = v.next;
};
return false;
};
fn errbadcase(c: *checker, pat: *node) void = {
os.write(2, "case: not a variant of scrutinee".ptr, 32u64);
if (pat != nil) {
if (pat.kind == nkind.N_TNAME) {
os.write(2, " (".ptr, 2u64);
os.write(2, pat.str.ptr, pat.str.len: u64);
os.write(2, ")".ptr, 1u64);
};
};
os.write(2, "\n".ptr, 1u64);
c.errs += 1;
};
fn checkmatchexhaust(c: *checker, n: *node) void = {
if (n == nil) { return; };
if (n.lhs == nil) { return; };
let st: *node = scruttype(c, n.lhs);
let u: *node = resolvealias(c, unwrapbang(st));
if (u == nil) { return; };
if (u.kind != nkind.N_TTAGGED) { return; };
// Validity: every `case T` pattern (and multi-pattern alts)
// must name a variant of u. Catches typos and dead arms that
// the dispatch would never reach.
let cs0: *node = n.list;
for (cs0 != nil) {
if (cs0.lhs != nil) {
if (!casevariantin(u, cs0.lhs)) {
errbadcase(c, cs0.lhs);
};
let alt: *node = cs0.list;
for (alt != nil) {
if (!casevariantin(u, alt)) {
errbadcase(c, alt);
};
alt = alt.next;
};
};
cs0 = cs0.next;
};
// Default arm absorbs anything; skip exhaustiveness.
let cs: *node = n.list;
for (cs != nil) {
if (cs.lhs == nil) { return; }; // default
cs = cs.next;
};
// For each variant of u, look for a covering case.
let v: *node = u.list;
for (v != nil) {
let covered: bool = false;
let cs2: *node = n.list;
for (cs2 != nil) {
if (casecovers(c, cs2, v)) {
covered = true;
cs2 = nil;
} else {
cs2 = cs2.next;
};
};
if (!covered) { errmatchvariant(c, n, v); };
v = v.next;
};
};
// ---- let init / return assignability --------------------------------
//
// AST-level approximation: when we can infer src's type and dst is
// explicitly declared, verify isassignable. We only emit an error
// when isassignable says "false with confidence." If we can't tell
// (binary ops, complex exprs we don't infer), we stay quiet — full
// type inference lives only on the C side.
fn errnotassign(c: *checker, dst: *node, src: *node, where: str) void = {
os.write(2, where.ptr, where.len: u64);
os.write(2, ": not assignable".ptr, 16u64);
if (src != nil) {
if (src.kind == nkind.N_TNAME) {
os.write(2, " (".ptr, 2u64);
os.write(2, src.str.ptr, src.str.len: u64);
os.write(2, " → ".ptr, 5u64);
if (dst != nil) {
if (dst.kind == nkind.N_TNAME) {
os.write(2, dst.str.ptr, dst.str.len: u64);
};
};
os.write(2, ")".ptr, 1u64);
};
};
os.write(2, "\n".ptr, 1u64);
c.errs += 1;
};
fn checkletassign(c: *checker, n: *node) void = {
if (n == nil) { return; };
if (n.rhs == nil) { return; }; // no init
// hint = nil for A.6.0; A.6.1 will pass n.lhs once STRUCTLIT/ARRLIT
// arms consume it. Plumbing-only at this point.
let src: *node = exprtype(c, n.rhs, nil);
// Inferred binding (`let r = expr;`, no type annotation). Mirror
// cstage cmd/wcc/check.c:1477 clet `if (t == NULL && initt) t =
// type_default(initt);` and ref/harec/src/check.c:1422
// check_expr_binding. wwstage carries the let's type on decl.lhs
// (exprtype N_IDENT at L1546 reads s.decl.lhs); cstage carries it
// on Sym.type — same observable result, rule-10 byte-id holds.
// Defaulting (untyped_int → i32, etc.) is exprtype's job at use
// sites, not the binding site.
if (n.lhs == nil) {
if (src != nil) { n.lhs = src; };
return;
};
if (src == nil) { return; }; // can't infer
// #45: alloc([], n) defers element type to the let-init context
// (Hare-style). exprtype's alloc-slice branch synthesizes
// ([]u8 | nomem) / []u8 (for the ?/! wrap) with no LHS context;
// when the let declares []T, retype src to []T / ([]T | nomem)
// so isassignable sees exact equality. cgenstmt cglet drives the
// element size from n.lhs already (cmd/wcc/cgenstmt.ww), so this
// stays symmetric with cstage check.c clet's parallel retype.
if (n.lhs.kind == nkind.N_TSLICE) {
let wrapped: bool = false;
let inner: *node = n.rhs;
if (inner.kind == nkind.N_TRYPROP) {
wrapped = true;
inner = inner.lhs;
} else { if (inner.kind == nkind.N_TRYUNW) {
wrapped = true;
inner = inner.lhs;
}; };
if (inner != nil && inner.kind == nkind.N_CALL) {
let callee: *node = inner.lhs;
let a0: *node = inner.list;
let a1: *node = nil;
let a2: *node = nil;
if (a0 != nil) { a1 = a0.next; };
if (a1 != nil) { a2 = a1.next; };
if (callee != nil
&& callee.kind == nkind.N_IDENT
&& streq(callee.str, "alloc")
&& a0 != nil && a0.kind == nkind.N_ARRLIT
&& a0.list == nil
&& a1 != nil && a2 == nil) {
let shadowed: bool = false;
if (c.curmod.len > 0) {
if (scopelookupinmodule(c.cur, c.curmod, "alloc") != nil) {
shadowed = true;
};
};
if (!shadowed) {
let sl: *node = newnode(nkind.N_TSLICE, "", 0, 0);
sl.lhs = n.lhs.lhs;
if (wrapped) {
src = sl;
} else {
let nome: *node = mktname(c, "nomem");
sl.next = nome;
let tt: *node = newnode(nkind.N_TTAGGED, "", 0, 0);
tt.list = sl;
src = tt;
};
};
};
};
};
// #130: array-init accept-if-fits. When lhs is [N]T and rhs is an
// array literal, per-element check: foldable int literal →
// defcastfits range-check (reject out-of-range loud, rule-7/Drew —
// Hare range-checks at literal-value level); non-foldable →
// isassignable to the element type. This BOTH accepts in-range
// bare-int (the #130 headline, matching cstage) AND closes the
// wwstage over-accept where str→u8 / out-of-range silently passed
// (#146 merged). Mirrors cstage check.c arrlit_init_fits. Scoped
// to the array path; scalar-init range-check is a separate
// language-wide gap (#148).
if (n.lhs.kind == nkind.N_TARRAY) {
if (n.rhs.kind == nkind.N_ARRLIT) {
let elemtn: *node = n.lhs.lhs;
let at: *tinfo = tinfofornode(c, n.lhs);
let et: *tinfo = nil;
if (at != nil) { et = at.sub; };
for (et != nil && et.kind == tykind.TY_NAMED) { et = et.under; };
let e: *node = n.rhs.list;
for (e != nil) {
let skip: bool = false;
if (e.kind == nkind.N_FIELD) {
if (streq(e.str, "...")) { skip = true; };
};
if (!skip) {
let ev: *node = e;
for (ev != nil && ev.kind == nkind.N_CAST) { ev = ev.lhs; };
let v: u64 = 0u64;
let folded: bool = false;
if (et != nil) {
if (typeisint(et)) {
if (ev != nil) {
folded = foldintliteral(ev, &v);
};
};
};
if (folded) {
if (!defcastfits(et, v)) {
let m: str = "let: array element out of range\n";
os.write(2, m.ptr, m.len: u64);
c.errs += 1;
return;
};
} else {
let est: *node = exprtype(c, ev, elemtn);
let conf2: bool = false;
if (est != nil) {
if (!isassignable(c, elemtn, est, &conf2)) {
if (conf2) {
errnotassign(c, elemtn, est, "let");
return;
};
};
};
};
};
e = e.next;
};
return;
};
};
let conf: bool = false;
let ok: bool = isassignable(c, n.lhs, src, &conf);
if (!conf) { return; };
if (!ok) { errnotassign(c, n.lhs, src, "let"); };
};
fn checkretassign(c: *checker, n: *node) void = {
if (n == nil) { return; };
if (n.lhs == nil) {
// bare `return;` — OK iff fnret is void or a tagged union
// with a void variant. Skip flagging for now; cgen handles
// the void-variant tag synthesis already.
return;
};
if (c.fnret == nil) { return; };
let src: *node = exprtype(c, n.lhs, nil);
if (src == nil) { return; };
let conf: bool = false;
let ok: bool = isassignable(c, c.fnret, src, &conf);
if (!conf) { return; };
if (!ok) { errnotassign(c, c.fnret, src, "return"); };
};
// ---- is / as validity ------------------------------------------------
//
// `e is T` and `e as T` require that e's declared type be a tagged
// union and that T name one of its variants. Operates on AST type
// expressions; falls back silently when we can't determine e's
// type (matches the case-variant rule for match).
fn checkisas(c: *checker, n: *node) void = {
if (n == nil) { return; };
// e is in n.lhs (value), T is in n.rhs (type expr).
let st: *node = scruttype(c, n.lhs);
let u: *node = resolvealias(c, unwrapbang(st));
if (u == nil) { return; };
// #52: enum ↔ int reinterpret (`enum as intT` / `intT as enum`).
// Mirrors cstage cmd/wcc/check.c:1346-1357 — N_TYPEASSERT with an
// enum on either side and integer types on both reinterprets in
// the same register, no tag check involved. Returns early before
// the tagged-union gate so lib/time/instant.ww `(c as i32)` and
// the lib/os syscall casts stop false-positiving. `is` (TYPETEST)
// stays rejected on non-tagged operands — cstage cmd/wcc/check.c
// gates the bypass on N_TYPEASSERT only.
if (n.kind == nkind.N_TYPEASSERT) {
let v: *node = resolvealias(c, unwrapbang(n.rhs));
let lhsenum: bool = false;
let rhsenum: bool = false;
if (u != nil) { if (u.kind == nkind.N_TENUM) { lhsenum = true; }; };
if (v != nil) { if (v.kind == nkind.N_TENUM) { rhsenum = true; }; };
if (lhsenum || rhsenum) {
if (isinttypeast(u)) { if (isinttypeast(v)) { return; }; };
};
};
if (u.kind != nkind.N_TTAGGED) {
os.write(2, "is/as: operand is not a tagged union\n".ptr, 37u64);
c.errs += 1;
return;
};
let want: *node = n.rhs;
if (want == nil) { return; };
if (!casevariantin(u, want)) {
os.write(2, "is/as: not a variant of operand".ptr, 31u64);
if (want.kind == nkind.N_TNAME) {
os.write(2, " (".ptr, 2u64);
os.write(2, want.str.ptr, want.str.len: u64);
os.write(2, ")".ptr, 1u64);
};
os.write(2, "\n".ptr, 1u64);
c.errs += 1;
};
};
// ---- ? subset propagation --------------------------------------------
//
// For `expr?`, the operand's error subset must be a subset of the
// enclosing fn's return-type variants. Mirrors C check.c. Operand
// is nkind.N_TRYPROP; its lhs is the value-bearing expr; we look at the
// expr's *declared* type for nkind.N_IDENT/nkind.N_CALL cases.
fn exprtypeoftry(c: *checker, e: *node) *node = {
if (e == nil) { return nil; };
if (e.kind == nkind.N_IDENT) {
let s: *sym = scopelookup(c.cur, e.str);
if (s == nil) { return nil; };
if (s.decl == nil) { return nil; };
return s.decl.lhs;
};
if (e.kind == nkind.N_CALL) {
// callee return type lookup: callee is e.lhs (nkind.N_IDENT or
// nkind.N_DOT). We need the fn-decl's lhs (return-type AST).
let callee: *node = e.lhs;
if (callee == nil) { return nil; };
let nm: str;
nm.ptr = nil; nm.len = 0;
if (callee.kind == nkind.N_IDENT) { nm = callee.str; };
if (callee.kind == nkind.N_DOT) { nm = callee.str; };
if (nm.len == 0) { return nil; };
let s: *sym = scopelookup(c.cur, nm);
if (s == nil) { return nil; };
if (s.skind != skind.SK_FN) { return nil; };
if (s.decl == nil) { return nil; };
return s.decl.lhs;
};
return nil;
};
fn checktryprop(c: *checker, n: *node) void = {
if (n == nil) { return; };
let t: *node = exprtypeoftry(c, n.lhs);
let u: *node = resolvealias(c, unwrapbang(t));
if (u == nil) { return; };
if (u.kind != nkind.N_TTAGGED) { return; };
// Does the operand have any error variants?
let haserr: bool = false;
let v: *node = u.list;
for (v != nil) {
if (iserrvariant(c, u, v)) { haserr = true; };
v = v.next;
};
if (!haserr) { return; };
// Enclosing fn must return a tagged union with each operand
// error variant present.
let r: *node = resolvealias(c, unwrapbang(c.fnret));
if (r == nil) {
os.write(2, "?: enclosing fn has no tagged-union return\n".ptr, 43u64);
c.errs += 1;
return;
};
if (r.kind != nkind.N_TTAGGED) {
os.write(2, "?: enclosing fn return is not tagged\n".ptr, 37u64);
c.errs += 1;
return;
};
let ev: *node = u.list;
for (ev != nil) {
if (iserrvariant(c, u, ev)) {
let found: bool = false;
let rv: *node = r.list;
for (rv != nil) {
if (typeeqast(rv, ev)) {
found = true;
rv = nil;
} else { rv = rv.next; };
};
if (!found) {
os.write(2, "?: error variant not in enclosing return\n".ptr, 41u64);
c.errs += 1;
};
};
ev = ev.next;
};
};
// install_param — when entering a fn body, define its params in a
// fresh local scope.
//
// TODO(#11): cstage check.c (post-#32) errors `param '%s' redeclared`
// when two params share a name. The fn body's scope IS fresh here
// (resolvefnbody opens it before calling us), so guarding scopedefine's
// nil return would be sound — but we defer until #11 wires checkfile
// into w6c_ww so the diagnostic class lands as a single coordinated
// step rather than dribbling in. Matches the cstage-only neg-case
// precedent at test/wcc/708 + test/wcc/696.
fn installparams(c: *checker, params: *node) void = {
let p: *node = params;
for (p != nil) {
if (p.kind == nkind.N_PARAM) {
// Hare-style variadic `T...`: normalize p.lhs to []T so
// downstream consumers (N_IDENT exprtype lookups via
// s.decl.lhs, cgen's variadic-slot synthesis) see the
// effective slice type. Mirrors cstage check.c:455
// `tp->type = type_slice(c->a, pt)` and harec
// check_func_type. Surface-fidelity preserved: wwdump
// -a runs parser only and never reaches this mutation.
if (p.op == tkind.TK_ELLIPSIS) {
if (p.lhs != nil && p.lhs.kind != nkind.N_TSLICE) {
let sl: *node = newnode(nkind.N_TSLICE, "", 0, 0);
sl.lhs = p.lhs;
p.lhs = sl;
};
};
let nm: str = p.str;
if (nm.len > 0) {
checkmoduleshadow(c, nm, "param");
scopedefine(c.cur, nm, skind.SK_PARAM, nil, p);
};
};
p = p.next;
};
};
// resolvefnbody — open a child scope for the fn, install its params,
// then walk the body. Local lets installed by walk_stmt (a future
// extension); for the current pass we just resolve-walk without
// per-statement scopes.
fn resolvefnbody(c: *checker, fnnode: *node) void = {
let outer: *scope = c.cur;
c.cur = newscope(c.cur);
installparams(c, fnnode.list);
// #61 audit §1.8 — A.2: walk each param's declared type-expr so
// tinfofornode stamps n.type_ on it. installparams binds the name
// but never recurses into the type; without this, cgen's slotsize
// fast-path hits the fallback for every param load/store.
let p: *node = fnnode.list;
for (p != nil) {
if (p.kind == nkind.N_PARAM) {
if (p.lhs != nil) { resolvewalk(c, p.lhs); };
};
p = p.next;
};
let prevret: *node = c.fnret;
c.fnret = fnnode.lhs; // return type AST, used by `?` check
if (fnnode.body != nil) {
resolvewalk(c, fnnode.body);
};
c.fnret = prevret;
c.cur = outer;
};
// isassertfam — `abort`/`assert` are language builtins, not value
// calls. harec models each as a dedicated EXPR_ASSERT whose result is
// builtin void (assert) or never (bare abort) at
// ref/harec/src/check.c:877,893; there is no callee ident, so nothing
// is left untyped. wwstage parses them as an N_CALL over a bare
// N_IDENT callee that binds to no decl, so both the call and its
// callee carry no type by design. Recognized exactly as the cstage
// builtin intercept (cmd/wcc/check.c:1314,1328): the reserved name
// with no shadowing user symbol.
fn isassertfam(c: *checker, id: *node) bool = {
if (id == nil) { return false; };
if (id.kind != nkind.N_IDENT) { return false; };
if (!streq(id.str, "abort") && !streq(id.str, "assert")) {
return false;
};
return scopelookupprefer(c.cur, c.curmod, id.str) == nil;
};
// asserttyped — post-checker invariant gate (#15, A.6.2.1e). Walks the
// file tree and fires for any node in resolvewalk's value-producing
// dispatch set (L474-489) whose n.type_ remained nil. Mirror of harec's
// `assert(expr->result)` at ref/harec/src/check.c:3810. The invariant
// is ARMED: a non-exempt nil-typed value node writes its one-line
// diagnostic to stderr and bails (os.exit 1), so a stamping regression
// fails loud rather than shipping a partially-typed tree. The
// 990_selfhost / 901 probes drive the wwstage checker over the resolved
// units that exercise this gate.
//
// Gates (per Drew 2026-05-22 — "guards value-producing expression
// nodes; SK_USE refs and bare builtin callees are syntactic positions,
// gate them out with WHY pointing at #19"):
//
// 1. N_IDENT whose resolved sym kind is SK_USE — module references
// (`os` in `os.write`). Harec models these via EXPR_ACCESS whose
// lookup-target is an OBJ_USE directly; there is no intermediate
// "ident-as-value" expr. Until #19 ports that AST shape, skip.
// 2. N_IDENT whose resolved sym has decl == nil — pseudo-builtin
// callees (len/append/free/alloc/size/align/offset, seeded in
// checkinit L85-97 with decl=nil). Harec spells these as
// dedicated EXPR_* kinds (EXPR_LEN, EXPR_APPEND, EXPR_FREE,
// EXPR_ALLOC at ref/harec/src/check.c:2630/745/2443/...).
// Drew's δ (#19) retires the seeded-SK_FN-with-nil-decl hack.
// 3. N_IDENT at the LHS-of-N_DOT syntactic position — the bare
// name half of a member-access expr is a lookup target, not a
// value-producing sub-expression. Harec's EXPR_ACCESS stores the
// member as a string, not a node.
// 4. The EXPR_ASSERT family — an N_CALL whose callee is `abort` or
// `assert`, and the bare N_IDENT callee itself (see isassertfam).
// harec's EXPR_ASSERT carries a void/never result with no callee
// ident (ref/harec/src/check.c:877,893); wwstage's
// N_CALL-over-bare-ident shape leaves both nodes nil by design.
//
// `indot` tracks gate 3: true only when the immediate caller is an
// N_DOT recursing into its .lhs.
fn asserttyped(c: *checker, n: *node, indot: bool) void = {
if (n == nil) { return; };
let k: nkind = n.kind;
let isexpr: bool =
k == nkind.N_INTLIT || k == nkind.N_FLOATLIT ||
k == nkind.N_STRLIT || k == nkind.N_RUNELIT ||
k == nkind.N_TRUE || k == nkind.N_FALSE ||
k == nkind.N_NIL || k == nkind.N_VOIDLIT ||
k == nkind.N_IDENT || k == nkind.N_BIN ||
k == nkind.N_UN || k == nkind.N_CALL ||
k == nkind.N_INDEX || k == nkind.N_CAST ||
k == nkind.N_STRUCTLIT || k == nkind.N_ARRLIT ||
k == nkind.N_RECV || k == nkind.N_DOT ||
k == nkind.N_SLICE || k == nkind.N_SPREAD ||
k == nkind.N_TUPLE || k == nkind.N_TRYPROP ||
k == nkind.N_TRYUNW || k == nkind.N_TYPETEST ||
k == nkind.N_TYPEASSERT || k == nkind.N_YIELD ||
k == nkind.N_MATCH;
let skip: bool = false;
if (isexpr && k == nkind.N_IDENT) {
if (indot) { skip = true; };
if (!skip) {
let s: *sym = scopelookup(c.cur, n.str);
if (s != nil) {
if (s.skind == skind.SK_USE) { skip = true; };
if (s.decl == nil) { skip = true; };
};
};
if (!skip) { if (isassertfam(c, n)) { skip = true; }; };
};
if (isexpr && k == nkind.N_CALL) {
if (isassertfam(c, n.lhs)) { skip = true; };
};
if (isexpr && !skip) {
if (n.type_ == nil) {
os.write(2, "asserttyped: ".ptr, 13u64);
let kn: str = nkname(k);
os.write(2, kn.ptr, kn.len: u64);
os.write(2, " ".ptr, 1u64);
if (n.file.len > 0) {
os.write(2, n.file.ptr, n.file.len: u64);
os.write(2, ":".ptr, 1u64);
let ls: str = strconv.i32tos(n.line, strconv.base.DEC);
os.write(2, ls.ptr, ls.len: u64);
};
if (n.str.len > 0) {
os.write(2, " '".ptr, 2u64);
os.write(2, n.str.ptr, n.str.len: u64);
os.write(2, "'".ptr, 1u64);
};
os.write(2, "\n".ptr, 1u64);
os.exit(1);
};
};
if (k == nkind.N_DOT) {
if (n.lhs != nil) { asserttyped(c, n.lhs, true); };
return;
};
if (n.attr != nil) { asserttyped(c, n.attr, false); };
if (n.lhs != nil) { asserttyped(c, n.lhs, false); };
if (n.rhs != nil) { asserttyped(c, n.rhs, false); };
if (n.cond != nil) { asserttyped(c, n.cond, false); };
if (n.body != nil) { asserttyped(c, n.body, false); };
if (n.els != nil) { asserttyped(c, n.els, false); };
let m: *node = n.list;
for (m != nil) {
asserttyped(c, m, false);
m = m.next;
};
};
export fn checkinit(c: *checker, tc: *tctx) void = {
c.tc = tc;
c.top = newscope(nil);
c.cur = c.top;
c.nresolved = 0;
c.nunresolved = 0;
c.errs = 0;
c.verbose = 0;
c.fnret = nil;
let empty: str;
c.curmod = empty;
c.file = nil;
seedprimitives(c);
};
export fn checkfile(c: *checker, file: *node) void = {
if (file == nil) { return; };
if (file.kind != nkind.N_FILE) { return; };
c.file = file;
// Pass 1: install all top-level names.
let d: *node = file.list;
for (d != nil) {
installdecl(c, file, d);
d = d.next;
};
// Pass 2: walk decl bodies/types and resolve identifiers.
// Track the per-decl module bareword so bare-leaf lookups inside
// the body prefer same-module entries over alphabetically-earlier
// same-leaf imports.
d = file.list;
for (d != nil) {
c.curmod = declmod(file, d);
// A.6.2.1-pre — attr-subtree gap: top-level dispatch below walks
// d.lhs / d.body per kind but never d.attr, leaving `@symbol("…")`
// arg literals (N_STRLIT) outside the post-order exprtype
// dispatch. Mirror resolvewalk L405 which descends n.attr on
// inner nodes.
if (d.attr != nil) { resolvewalk(c, d.attr); };
let k: nkind = d.kind;
if (k == nkind.N_FNDECL) {
if (d.lhs != nil) { resolvewalk(c, d.lhs); }; // return type
resolvefnbody(c, d);
} else { if (k == nkind.N_DEF) {
if (d.lhs != nil) { resolvewalk(c, d.lhs); };
if (d.rhs != nil) { resolvewalk(c, d.rhs); };
// #88: const-fold sibling/imported def refs, casts, and
// arithmetic so cgen's literal-only emitdefconstants can
// lay down the DATA row. GATED on the plain literal fold
// missing first, so existing literal/unary defs keep
// their rhs node and the emitted bytes stay byte-identical.
if (d.rhs != nil) {
let dv: u64 = 0u64;
if (!foldintliteral(d.rhs, &dv)) {
if (evaldefconst(c, d.rhs, &dv, 0)) {
stampintlit(d.rhs, dv);
};
};
};
} else { if (k == nkind.N_TYPEDECL) {
if (d.lhs != nil) { resolvewalk(c, d.lhs); };
} else { if (k == nkind.N_LET) {
if (d.lhs != nil) { resolvewalk(c, d.lhs); };
if (d.rhs != nil) { resolvewalk(c, d.rhs); };
// #130: top-level let assignability — the subtree
// resolvewalk above stamps types but never runs the
// init-assignability check (function-body lets get it
// via resolvewalk's post-order L247; top-level lets
// were missed). Needed for the array accept-if-fits
// range-check to fire on module-level `let A:[N]u8=[..]`.
checkletassign(c, d);
};};};};
d = d.next;
};
// Pass 3 (#15, A.6.2.1e): post-checker invariant gate. Walks each
// decl with its curmod set so asserttyped's gate lookups resolve
// against the same module context exprtype saw during pass 2.
d = file.list;
for (d != nil) {
c.curmod = declmod(file, d);
asserttyped(c, d, false);
d = d.next;
};
let empty: str;
c.curmod = empty;
};