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ww: cgen trap batch (def-str field, chained-ptr write, scalar+str tuple ABI)

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Hojun-Cho
2026-05-11 20:49:21 +09:00
parent 2ac15e4e99
commit c5f30f2fce
14 changed files with 1629 additions and 67 deletions
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234
cmd/w6c/cgen.c
View File

@@ -1038,6 +1038,111 @@ cgexpr(Cg *c, Node *n, Local *locals)
break;
}
}
/* Chained `<expr>.field = v` where <expr> evaluates to a *struct.
* cgexpr on the inner expression already returns the pointer;
* we then store at (ptr + field.offset). Without this, only the
* single-level N_IDENT base above is wired and shapes like
* `r.sym.flag = 1` (where r.sym: *T) silently emit no store —
* the read still works because the chained-N_DOT read path is
* wired below. (This was trap 1 of the cgen miscompilations.) */
if (n->lhs && n->lhs->kind == N_DOT && n->lhs->lhs
&& n->lhs->lhs->kind != N_IDENT) {
Type *bt = n->lhs->lhs->type;
Type *bu = (bt && bt->kind == TY_NAMED) ? bt->under : bt;
if (bu && bu->kind == TY_PTR && bu->sub) {
Type *inner = bu->sub;
if (inner->kind == TY_NAMED) inner = inner->under;
if (inner && inner->kind == TY_STRUCT) {
Tfield *f = NULL;
for (Tfield *fl = inner->fields; fl; fl = fl->next)
if (strcmp(fl->name, n->lhs->str) == 0)
{ f = fl; break; }
if (f != NULL) {
Type *ft = f->type;
Type *fu = (ft && ft->kind == TY_NAMED)
? ft->under : ft;
int fsz = (int)(ft ? ft->size : 8);
int signed_field = ft && (
ft->kind == TY_I8 ||
ft->kind == TY_I16 ||
ft->kind == TY_I32);
int store_op = A_MOVQ;
if (fsz == 1) store_op = A_MOVB;
else if (fsz == 4) store_op = A_MOVL;
int foff = (int)f->offset;
if (n->op == TK_ASSIGN) {
if (fu && fu->kind == TY_STR) {
/* str rhs: (AX=ptr, BX=len). Stash
* both, then load the struct ptr
* into CX and write both halves. */
cgexpr(c, n->rhs, locals);
ins1(c, A_PUSHQ, areg(D_BX));
ins1(c, A_PUSHQ, areg(D_AX));
cgexpr(c, n->lhs->lhs, locals);
ins2(c, A_MOVQ, areg(D_AX),
areg(D_CX));
ins1(c, A_POPQ, areg(D_AX));
ins1(c, A_POPQ, areg(D_BX));
ins2(c, A_MOVQ, areg(D_AX),
amem(D_CX, foff + 0));
ins2(c, A_MOVQ, areg(D_BX),
amem(D_CX, foff + 8));
} else {
cgexpr(c, n->rhs, locals);
ins1(c, A_PUSHQ, areg(D_AX));
cgexpr(c, n->lhs->lhs, locals);
ins2(c, A_MOVQ, areg(D_AX),
areg(D_BX));
ins1(c, A_POPQ, areg(D_AX));
ins2(c, store_op, areg(D_AX),
amem(D_BX, foff));
}
break;
}
/* compound op: AX=rhs → push; eval ptr → push;
* load old field → AX; pop ptr→BX, rhs→CX;
* combine; store. Float/str compound on a
* chained pointer-field is not wired. */
cgexpr(c, n->rhs, locals);
ins1(c, A_PUSHQ, areg(D_AX));
cgexpr(c, n->lhs->lhs, locals);
ins1(c, A_PUSHQ, areg(D_AX));
int load_op = A_MOVQ;
if (fsz == 1) load_op = A_MOVZBQ;
else if (fsz == 4)
load_op = signed_field ? A_MOVSXD : A_MOVL;
ins2(c, load_op, amem(D_AX, foff),
areg(D_AX));
ins1(c, A_POPQ, areg(D_BX));
ins1(c, A_POPQ, areg(D_CX));
switch (n->op) {
case TK_PLUSEQ:
ins2(c, A_ADDQ, areg(D_CX), areg(D_AX));
break;
case TK_MINUSEQ:
ins2(c, A_SUBQ, areg(D_CX), areg(D_AX));
break;
case TK_STAREQ:
ins2(c, A_IMULQ, areg(D_CX), areg(D_AX));
break;
case TK_AMPEQ:
ins2(c, A_ANDQ, areg(D_CX), areg(D_AX));
break;
case TK_PIPEEQ:
ins2(c, A_ORQ, areg(D_CX), areg(D_AX));
break;
case TK_CARETEQ:
ins2(c, A_XORQ, areg(D_CX), areg(D_AX));
break;
default: break;
}
ins2(c, store_op, areg(D_AX),
amem(D_BX, foff));
break;
}
}
}
}
/* float assignment to a local */
if (n->lhs && n->lhs->kind == N_IDENT && node_isfloat(n)) {
cgexpr(c, n->rhs, locals); /* X0 */
@@ -1887,6 +1992,29 @@ cgexpr(Cg *c, Node *n, Local *locals)
&& (lenfld || capfld || ptrfld)) {
if (n->lhs->kind == N_IDENT) {
int off = localfind(locals, n->lhs->str);
if (off == 0) {
/* Not a local — could be `def NAME: str
* = "lit"`. Sdef-backed strs aren't laid
* out in memory; emit .ptr/.len from the
* literal directly, mirroring the bare
* N_IDENT branch above. Without this we'd
* load BP+8 (return-address slot) as the
* "len". */
for (Sdef *s = sdefs; s; s = s->next) {
if (strcmp(s->name, n->lhs->str) != 0)
continue;
if (ptrfld) {
const char *lab = intern_strlit(c,
s->bytes, s->len);
ins2(c, A_LEAQ, asym(lab), areg(D_AX));
} else {
ins2(c, A_MOVQ,
aimm((long long)s->len),
areg(D_AX));
}
goto dot_done;
}
}
int delta = ptrfld ? 0 : (lenfld ? 8 : 16);
ins2(c, A_MOVQ, amem(D_BP, off + delta),
areg(D_AX));
@@ -1925,6 +2053,8 @@ cgexpr(Cg *c, Node *n, Local *locals)
}
if (tp != NULL) {
int fsz = (int)(tp->type ? tp->type->size : 8);
Type *fu = (tp->type && tp->type->kind == TY_NAMED)
? tp->type->under : tp->type;
int signed_field = tp->type && (
tp->type->kind == TY_I8 ||
tp->type->kind == TY_I16 ||
@@ -1933,6 +2063,15 @@ cgexpr(Cg *c, Node *n, Local *locals)
if (fsz == 1) op = A_MOVZBQ;
else if (fsz == 4) op = signed_field ? A_MOVSXD : A_MOVL;
int off = localfind(locals, n->lhs->str);
/* str element: load (ptr, len) into (AX, BX) so chains
* like `t.1.len` propagate through the str-rhs
* convention. Without this we'd MOVQ 8B and the .len
* shuffle (BX→AX) would surface garbage. */
if (fu && fu->kind == TY_STR) {
ins2(c, A_MOVQ, amem(D_BP, off + foff + 0), areg(D_AX));
ins2(c, A_MOVQ, amem(D_BP, off + foff + 8), areg(D_BX));
break;
}
ins2(c, op, amem(D_BP, off + foff), areg(D_AX));
}
break;
@@ -2225,6 +2364,37 @@ cgstmt(Cg *c, Node *n, Local **locals, int *frame)
ins2(c, A_MOVQ, areg(D_DX), amem(D_BP, off + 8));
break;
}
/* 24B tuple initialiser for `(scalar, str)` / `(str, scalar)`.
* Per the AX:DX:CX return convention: AX = scalar elem,
* DX = str.ptr, CX = str.len. The slot is laid out positionally
* (e0 at +0, e1 at +8 for scalars; str takes 16B starting at
* its position), so we route each register to the slot dictated
* by the element's type, not by AX/DX position. */
if (n->rhs && lu && lu->kind == TY_TUPLE && sz == 24) {
Tparam *p0 = lu->params;
Tparam *p1 = p0 ? p0->next : NULL;
Type *t0 = p0 ? p0->type : NULL;
Type *t1 = p1 ? p1->type : NULL;
Type *u0 = (t0 && t0->kind == TY_NAMED) ? t0->under : t0;
Type *u1 = (t1 && t1->kind == TY_NAMED) ? t1->under : t1;
int e0_str = u0 && u0->kind == TY_STR;
int e1_str = u1 && u1->kind == TY_STR;
if (e0_str ^ e1_str) {
cgexpr(c, n->rhs, *locals);
if (e0_str) {
/* layout: str@+0 (16B), scalar@+16. */
ins2(c, A_MOVQ, areg(D_DX), amem(D_BP, off + 0));
ins2(c, A_MOVQ, areg(D_CX), amem(D_BP, off + 8));
ins2(c, A_MOVQ, areg(D_AX), amem(D_BP, off + 16));
} else {
/* layout: scalar@+0 (8B), str@+8 (16B). */
ins2(c, A_MOVQ, areg(D_AX), amem(D_BP, off + 0));
ins2(c, A_MOVQ, areg(D_DX), amem(D_BP, off + 8));
ins2(c, A_MOVQ, areg(D_CX), amem(D_BP, off + 16));
}
break;
}
}
/* Tagged-union initialiser. Two shapes:
* 1) rhs already produces a tagged-union value (e.g. a fn
* call returning (T | E)). cgexpr leaves AX=tag,
@@ -2496,14 +2666,34 @@ cgstmt(Cg *c, Node *n, Local **locals, int *frame)
break;
}
if (n->lhs && n->lhs->kind == N_TUPLE) {
/* small tuples (≤2 elems, ≤8B each) return in AX:DX */
/* 2-tuple ABI:
* (scalar, scalar) — AX = e0, DX = e1. (16B, fits SysV.)
* (scalar, str) — AX = scalar elem,
* DX = str.ptr, CX = str.len. (24B custom.)
* (str, scalar) — same regs, type-keyed not position-keyed.
*
* The 24B convention mirrors the existing tagged-union return
* (AX:DX:CX); receive sites destructure off the same regs. */
Node *e0 = n->lhs->list;
Node *e1 = e0 ? e0->next : NULL;
if (e1 && e1->next == NULL) {
cgexpr(c, e1, *locals);
ins1(c, A_PUSHQ, areg(D_AX));
cgexpr(c, e0, *locals);
ins1(c, A_POPQ, areg(D_DX));
int e0_is_str = node_isstr(e0);
int e1_is_str = node_isstr(e1);
if (e0_is_str ^ e1_is_str) {
Node *strn = e0_is_str ? e0 : e1;
Node *scaln = e0_is_str ? e1 : e0;
cgexpr(c, scaln, *locals); /* AX = scalar */
ins1(c, A_PUSHQ, areg(D_AX));
cgexpr(c, strn, *locals); /* AX=ptr, BX=len */
ins2(c, A_MOVQ, areg(D_BX), areg(D_CX));
ins2(c, A_MOVQ, areg(D_AX), areg(D_DX));
ins1(c, A_POPQ, areg(D_AX));
} else {
cgexpr(c, e1, *locals);
ins1(c, A_PUSHQ, areg(D_AX));
cgexpr(c, e0, *locals);
ins1(c, A_POPQ, areg(D_DX));
}
} else {
/* >2-tuple not yet implemented; fall back to first elem */
if (e0) cgexpr(c, e0, *locals);
@@ -2681,11 +2871,41 @@ cgstmt(Cg *c, Node *n, Local **locals, int *frame)
break;
}
case N_MLET: {
/* eval rhs; first result in AX, second in DX. Bind both. */
/* eval rhs; consume the per-type return-ABI registers.
* (scalar, scalar) — AX → l0, DX → l1.
* (scalar, str) — AX → scalar slot, (DX, CX) → str slot
* as (.ptr, .len). Position-agnostic.
* Local sizing comes from each l->type so the str slot gets
* the full 16B; without this, only DX would land and the
* len half (CX) would have nowhere to go. */
cgexpr(c, n->rhs, *locals);
ins1(c, A_PUSHQ, areg(D_DX)); /* save 2nd while we store 1st */
Node *l0 = n->list;
Node *l1 = l0 ? l0->next : NULL;
Type *t0 = l0 ? l0->type : NULL;
Type *t1 = l1 ? l1->type : NULL;
Type *u0 = (t0 && t0->kind == TY_NAMED) ? t0->under : t0;
Type *u1 = (t1 && t1->kind == TY_NAMED) ? t1->under : t1;
int s0_is_str = u0 && u0->kind == TY_STR;
int s1_is_str = u1 && u1->kind == TY_STR;
if (l0 && l1 && (s0_is_str ^ s1_is_str)) {
int sz0 = s0_is_str ? 16 : 8;
int sz1 = s1_is_str ? 16 : 8;
int off0 = localoff(c, locals, l0->str, sz0, frame);
int off1 = localoff(c, locals, l1->str, sz1, frame);
if (s0_is_str) {
/* l0 is str: ptr=DX, len=CX. l1 is scalar: l1 = AX. */
ins2(c, A_MOVQ, areg(D_DX), amem(D_BP, off0 + 0));
ins2(c, A_MOVQ, areg(D_CX), amem(D_BP, off0 + 8));
ins2(c, A_MOVQ, areg(D_AX), amem(D_BP, off1));
} else {
/* l0 is scalar; l1 is str. */
ins2(c, A_MOVQ, areg(D_AX), amem(D_BP, off0));
ins2(c, A_MOVQ, areg(D_DX), amem(D_BP, off1 + 0));
ins2(c, A_MOVQ, areg(D_CX), amem(D_BP, off1 + 8));
}
break;
}
ins1(c, A_PUSHQ, areg(D_DX)); /* save 2nd while we store 1st */
if (l0) {
int off = localoff(c, locals, l0->str, 8, frame);
ins2(c, A_MOVQ, areg(D_AX), amem(D_BP, off));

2
lib/ww/CLAUDE.md
View File

@@ -10,4 +10,4 @@ This directory is **not** a Hare-style stdlib module — it's a compiler-fronten
When porting from `cmd/wcc/*.c`:
- Keep the same data layout. The selfhost goal is byte-compatible structures so dump/inspect tools work either way.
- Read `cmd/wcc/ww.h` first for canonical field names and ordering.
- See `selfhost/CLAUDE.md` for the wwstage cgen traps to avoid (two-level field write, `(scalar,str)` tuple return, `def : str`, undersized `amalloc`).
- See `selfhost/CLAUDE.md` for the wwstage cgen traps to avoid (undersized `amalloc`).

14
lib/ww/parse/expr.ww
View File

@@ -281,9 +281,17 @@ fn parsepostfix(p: *parser, lhs: *node) *node = {
advance(p);
let n: *node = newnode(p.a, N_DOT, pf, pl, pc);
n.lhs = cur;
let id: str;
expectident(p, &id);
n.str = id;
// Hare-style tuple field access: `t.0`, `t.1`. The
// numeric literal becomes the field name string so the
// cgen tuple-positional path matches `cmd/wcc/parse.c`.
if (p.curkind == TK_INT) {
n.str = p.curtext;
advance(p);
} else {
let id: str;
expectident(p, &id);
n.str = id;
};
cur = n;
continue;
};

66
lib/ww/parse/stmt.ww
View File

@@ -12,6 +12,42 @@ fn parseletlocal(p: *parser) *node = {
let is_const: i32 = 0;
if (p.curkind == TK_CONST) { is_const = 1; };
advance(p);
// Hare-style tuple destructure: `let (a, b) = expr;`.
// Types are optional per binding (matches C parser; Hare itself
// doesn't allow types here, but cmd/wcc/parse.c does).
if (p.curkind == TK_LPAREN) {
advance(p);
let m: *node = newnode(p.a, N_MLET, pf, pl, pc);
let head: *node = nil;
let tail: *node = nil;
for (true) {
let lpf: str = p.curfile;
let lpl: i32 = p.curline;
let lpc: i32 = p.curcol;
let l: *node = newnode(p.a, N_LET, lpf, lpl, lpc);
let id: str;
expectbindname(p, &id);
l.str = id;
if (accepttok(p, TK_COLON)) { l.lhs = parsetype(p); };
if (head == nil) { head = l; }
else { tail.next = l; };
tail = l;
if (!accepttok(p, TK_COMMA)) { break; };
};
expecttok(p, TK_RPAREN, "expected ')' in let destructure");
expecttok(p, TK_ASSIGN, "expected '=' after let destructure");
m.rhs = parseexpr(p);
expecttok(p, TK_SEMI, "expected ';' after let");
m.list = head;
if (is_const != 0) {
m.op = TK_CONST;
let lc: *node = head;
for (lc != nil) { lc.op = TK_CONST; lc = lc.next; };
};
return m;
};
let n: *node = newnode(p.a, N_LET, pf, pl, pc);
let id: str;
expectbindname(p, &id);
@@ -19,6 +55,36 @@ fn parseletlocal(p: *parser) *node = {
if (accepttok(p, TK_COLON)) {
n.lhs = parsetype(p);
};
// Comma-multi-let: `let n, s = call();` (ww extension over Hare).
// Collects (name, type) pairs, then '=' rhs. Each binding gets
// its own N_LET; the wrapping N_MLET carries the rhs.
if (p.curkind == TK_COMMA) {
let m: *node = newnode(p.a, N_MLET, pf, pl, pc);
let head: *node = n;
let tail: *node = n;
for (accepttok(p, TK_COMMA)) {
let lpf: str = p.curfile;
let lpl: i32 = p.curline;
let lpc: i32 = p.curcol;
let l: *node = newnode(p.a, N_LET, lpf, lpl, lpc);
let id2: str;
expectbindname(p, &id2);
l.str = id2;
if (accepttok(p, TK_COLON)) { l.lhs = parsetype(p); };
tail.next = l;
tail = l;
};
expecttok(p, TK_ASSIGN, "expected '=' after let names");
m.rhs = parseexpr(p);
expecttok(p, TK_SEMI, "expected ';' after let");
m.list = head;
if (is_const != 0) {
m.op = TK_CONST;
let lc: *node = head;
for (lc != nil) { lc.op = TK_CONST; lc = lc.next; };
};
return m;
};
if (accepttok(p, TK_ASSIGN)) {
n.rhs = parseexpr(p);
};

34
selfhost/CLAUDE.md
View File

@@ -4,22 +4,28 @@ Identifiers: Plan 9 style. lowercase, words run together (`newbuf`, `tcpsock`, `
Syntax and idioms: Hare-shaped. Trailing `;`, `=` after fn/type signatures, `export` for visibility, `match`/`?`/`!` for tagged-union errors. Consult `ref/hare/` for canonical signatures and error-handling patterns before inventing your own.
The C bootstrap's cgen ("wwstage") has four known silent-miscompilation traps. They produce wrong runtime behavior, not compile errors. When porting C → ww here, default to the workarounds:
The C bootstrap's cgen has known silent-miscompilation traps. They produce wrong runtime behavior, not compile errors. When porting C → ww here, default to the workarounds:
1. **Two-level field write through pointer field doesn't stick.**
`r.sym.isdyn = 1` where `r.sym: *T` drops the write. Bind the inner pointer to a local first:
```
let sym: *lsym = r.sym;
sym.isdyn = 1;
```
1. **`amalloc(n)` with n < struct size silently corrupts neighbours.** No error — the bump arena hands out n bytes and field writes overflow into the next record. When introducing or growing a struct, audit every `amalloc(_, n)` call site and over-size (we routinely pass 48 for a 40-byte struct). Symptom: linked-list prepends lose all but the most recent entry.
2. **Tuple return `(scalar, str)` corrupts the str half.** Both ptr and len come back garbage. Split into two functions — one returns the scalar, another returns the str. Plain `str` returns are fine.
Fixed (no workaround needed):
3. **`def NAME: str = "...";` is broken.** The `.len` picks up an unrelated accumulator. Wrap the literal in a nullary fn instead:
```
fn namestr() str = { return "..."; };
```
4. **`amalloc(n)` with n < struct size silently corrupts neighbours.** No error — the bump arena hands out n bytes and field writes overflow into the next record. When introducing or growing a struct, audit every `amalloc(_, n)` call site and over-size (we routinely pass 48 for a 40-byte struct). Symptom: linked-list prepends lose all but the most recent entry.
- `def NAME: str = "..."` field access. `.len`/`.ptr` on an Sdef ident
now inline the literal length / strlit address rather than reading
BP+8. See cmd/w6c/cgen.c N_DOT.
- Two-level field write through pointer field: `r.sym.isdyn = 1` where
`r.sym: *T` now stores. The chained-N_DOT N_ASSIGN branch evaluates
the inner pointer and stores at *(ptr + field.offset). See
cmd/w6c/cgen.c N_ASSIGN and selfhost/cmd/wcc/cgenexpr.ww cgassign.
- Tuple return `(scalar, str)` (24B). Returns now follow an AX:DX:CX
convention: AX = scalar elem, DX = str.ptr, CX = str.len. Receive
sites all destructure off the same regs regardless of positional
order:
let n, s = call(); // ww comma form
let (n, s) = call(); // Hare-style paren form
let t: (i64, str) = call(); // positional t.0 / t.1.len
Wwstage parser + cgen are byte-identical to C cgen on these shapes.
See cmd/w6c/cgen.c N_RETURN/N_LET/N_DOT/N_MLET, lib/ww/parse/{stmt,
expr}.ww and selfhost/cmd/wcc/{cgenstmt,cgenexpr,cgenutil,cgendecl}.ww.
If a port "should work" but the binary is wrong, suspect these first.

447
selfhost/cmd/w6c/main.combined.ww
View File

@@ -2251,9 +2251,17 @@ fn parsepostfix(p: *parser, lhs: *node) *node = {
advance(p);
let n: *node = newnode(p.a, N_DOT, pf, pl, pc);
n.lhs = cur;
let id: str;
expectident(p, &id);
n.str = id;
// Hare-style tuple field access: `t.0`, `t.1`. The
// numeric literal becomes the field name string so the
// cgen tuple-positional path matches `cmd/wcc/parse.c`.
if (p.curkind == TK_INT) {
n.str = p.curtext;
advance(p);
} else {
let id: str;
expectident(p, &id);
n.str = id;
};
cur = n;
continue;
};
@@ -2374,6 +2382,42 @@ fn parseletlocal(p: *parser) *node = {
let is_const: i32 = 0;
if (p.curkind == TK_CONST) { is_const = 1; };
advance(p);
// Hare-style tuple destructure: `let (a, b) = expr;`.
// Types are optional per binding (matches C parser; Hare itself
// doesn't allow types here, but cmd/wcc/parse.c does).
if (p.curkind == TK_LPAREN) {
advance(p);
let m: *node = newnode(p.a, N_MLET, pf, pl, pc);
let head: *node = nil;
let tail: *node = nil;
for (true) {
let lpf: str = p.curfile;
let lpl: i32 = p.curline;
let lpc: i32 = p.curcol;
let l: *node = newnode(p.a, N_LET, lpf, lpl, lpc);
let id: str;
expectbindname(p, &id);
l.str = id;
if (accepttok(p, TK_COLON)) { l.lhs = parsetype(p); };
if (head == nil) { head = l; }
else { tail.next = l; };
tail = l;
if (!accepttok(p, TK_COMMA)) { break; };
};
expecttok(p, TK_RPAREN, "expected ')' in let destructure");
expecttok(p, TK_ASSIGN, "expected '=' after let destructure");
m.rhs = parseexpr(p);
expecttok(p, TK_SEMI, "expected ';' after let");
m.list = head;
if (is_const != 0) {
m.op = TK_CONST;
let lc: *node = head;
for (lc != nil) { lc.op = TK_CONST; lc = lc.next; };
};
return m;
};
let n: *node = newnode(p.a, N_LET, pf, pl, pc);
let id: str;
expectbindname(p, &id);
@@ -2381,6 +2425,36 @@ fn parseletlocal(p: *parser) *node = {
if (accepttok(p, TK_COLON)) {
n.lhs = parsetype(p);
};
// Comma-multi-let: `let n, s = call();` (ww extension over Hare).
// Collects (name, type) pairs, then '=' rhs. Each binding gets
// its own N_LET; the wrapping N_MLET carries the rhs.
if (p.curkind == TK_COMMA) {
let m: *node = newnode(p.a, N_MLET, pf, pl, pc);
let head: *node = n;
let tail: *node = n;
for (accepttok(p, TK_COMMA)) {
let lpf: str = p.curfile;
let lpl: i32 = p.curline;
let lpc: i32 = p.curcol;
let l: *node = newnode(p.a, N_LET, lpf, lpl, lpc);
let id2: str;
expectbindname(p, &id2);
l.str = id2;
if (accepttok(p, TK_COLON)) { l.lhs = parsetype(p); };
tail.next = l;
tail = l;
};
expecttok(p, TK_ASSIGN, "expected '=' after let names");
m.rhs = parseexpr(p);
expecttok(p, TK_SEMI, "expected ';' after let");
m.list = head;
if (is_const != 0) {
m.op = TK_CONST;
let lc: *node = head;
for (lc != nil) { lc.op = TK_CONST; lc = lc.next; };
};
return m;
};
if (accepttok(p, TK_ASSIGN)) {
n.rhs = parseexpr(p);
};
@@ -4368,6 +4442,23 @@ fn structlookup(c: *cgen, name: str) *structinfo = {
// primsize — size in bytes of a primitive type name (or 0 if not
// recognised as a primitive — the caller falls back to other paths).
// fldnumidx — parse a tuple field name like "0" / "1" / "12" into an
// index, or -1 if not all-digits. Used by cgdot to dispatch
// `t.0` / `t.1` against an N_TTUPLE local without pulling in strconv.
fn fldnumidx(s: str) i32 = {
if (s.len == 0) { return -1; };
let r: i32 = 0;
let i: i32 = 0;
for (i < s.len) {
let b: u8 = s[i];
if (b < 48u8) { return -1; };
if (b > 57u8) { return -1; };
r = r * 10 + ((b - 48u8): i32);
i += 1;
};
return r;
};
fn primsize(name: str) i32 = {
if (streq(name, "u8")) { return 1; };
if (streq(name, "i8")) { return 1; };
@@ -4441,7 +4532,19 @@ fn slotsize(c: *cgen, typn: *node) i32 = {
if (k == N_TFN) { return 8; };
if (k == N_TCHAN) { return 8; };
if (k == N_TSLICE) { return 24; };
if (k == N_TTUPLE) { return 16; };
if (k == N_TTUPLE) {
// Sum element sizes. Mirrors C cgen which uses raw type
// sizes; padding to 8 happens inside slotsize for primitives,
// so a `(i64, str)` resolves to 8 + 16 = 24 (matches the C
// cgen 24B init / positional-access layout).
let total: i32 = 0;
let p: *node = typn.list;
for (p != nil) {
total += slotsize(c, p);
p = p.next;
};
return total;
};
if (k == N_TTAGGED){ return 24; };
if (k == N_TNAME) {
let nm: str = typn.str;
@@ -5100,6 +5203,49 @@ fn cgdot(c: *cgen, n: *node) void = {
return;
};
};
// Hare-style tuple positional access: `t.0`, `t.1`.
// Walk the tuple element type list summing slotsize
// (matches the (scalar, str) init layout which puts
// the scalar in an 8B slot and the str in 16B). For
// a str element, load both halves into (AX, BX) so
// chains like `t.1.len` propagate correctly.
if (lkind == N_TTUPLE) {
let idx: i32 = fldnumidx(fld);
if (idx >= 0) {
let tp: *node = tn.list;
let foff: i32 = 0;
let i: i32 = 0;
for (i < idx) {
if (tp == nil) { i = idx; }
else {
foff += slotsize(c, tp);
tp = tp.next;
i += 1;
};
};
if (tp != nil) {
if (isstrtyperaw(tp)) {
emitline("\tMOVQ\t");
emitoff((lc.off + foff + 0): i64);
emitline("(BP), AX\n");
emitline("\tMOVQ\t");
emitoff((lc.off + foff + 8): i64);
emitline("(BP), BX\n");
return;
};
let sz: i32 = slotsize(c, tp);
let op: str = "MOVQ";
if (sz == 1) { op = "MOVZBQ"; }
else { if (sz == 4) { op = "MOVL"; }; };
emitline("\t");
emitline(op);
emitline("\t");
emitoff((lc.off + foff): i64);
emitline("(BP), AX\n");
return;
};
};
};
// str/slice pseudo-fields .ptr/.len/.cap on a
// direct local: load at slot+delta.
let delta: i32 = -1;
@@ -5730,6 +5876,71 @@ fn cgassign(c: *cgen, n: *node) void = {
};
};
};
// Chained `<expr>.field = v` where `<expr>` itself is a chain
// of dots resolving to a *struct. Mirrors the C cgen branch
// added to close trap 1 (cmd/w6c/cgen.c). Without this, only
// `local.field = v` and `local.fieldptr.field = v` get wired
// (the latter through the IDENT-base branch above) — chains
// like `s.last.snext = sy` (lib/ww/sym.ww) silently emit no
// store. Only plain `=` is wired here; chained compound on a
// pointer-field hasn't surfaced.
if (lhs != nil) {
if (lhs.kind == N_DOT) {
let base: *node = lhs.lhs;
let fld: str = lhs.str;
if (base != nil) {
if (base.kind == N_DOT) {
let innert: *node = dotinnerstructptr(c, base);
if (innert != nil) {
let sname: str = innert.str;
let si: *structinfo = structlookup(c, sname);
if (si != nil) {
let fi: *fieldinfo = si.fields;
for (fi != nil) {
if (streq(fi.fname, fld)) {
if (n.op == TK_ASSIGN) {
if (isstrtype(c, fi.tnode)) {
// str rhs: AX=ptr, BX=len.
// Stash both, then load
// the struct ptr into CX
// and write both halves.
cgexpr(c, n.rhs);
emitline("\tPUSHQ\tBX\n");
emitline("\tPUSHQ\tAX\n");
cgexpr(c, base);
emitline("\tMOVQ\tAX, CX\n");
emitline("\tPOPQ\tAX\n");
emitline("\tPOPQ\tBX\n");
emitline("\tMOVQ\tAX, ");
emitdispreg(fi.foff: i64, "CX");
emitline("\n");
emitline("\tMOVQ\tBX, ");
emitdispreg((fi.foff + 8): i64, "CX");
emitline("\n");
return;
};
cgexpr(c, n.rhs);
emitline("\tPUSHQ\tAX\n");
cgexpr(c, base);
emitline("\tMOVQ\tAX, BX\n");
emitline("\tPOPQ\tAX\n");
let sop: str = fieldstoreop(fi);
emitline("\t");
emitline(sop);
emitline("\tAX, ");
emitdispreg(fi.foff: i64, "BX");
emitline("\n");
return;
};
};
fi = fi.finext;
};
};
};
};
};
};
};
// Local-ident target — plain `=` and the simple compound
// forms (+= -= *= /=); other compounds fall back to
// "evaluate rhs, replace". Mirrors C cgen's IDENT-assign path.
@@ -5833,6 +6044,8 @@ fn cgstmt(c: *cgen, n: *node) void = {
if (k == N_MASSIGN) { cgmassign(c, n); return; };
if (k == N_MLET) { cgmlet(c, n); return; };
if (k == N_BREAK) { cgbreak(c, n); return; };
if (k == N_CONTINUE) { cgcontinue(c, n); return; };
@@ -5851,18 +6064,35 @@ fn cgblock(c: *cgen, n: *node) void = {
fn cgreturn(c: *cgen, n: *node) void = {
let rhs: *node = n.lhs;
if (rhs != nil) {
// Tuple return `return a, b;` — pack as (AX=v0, DX=v1).
// Matches C cgen: evaluate v1 first (PUSHQ), then v0
// into AX, then POPQ DX. End state: AX = v0, DX = v1.
// Tuple return `return a, b;`:
// (scalar, scalar) — AX = v0, DX = v1.
// (scalar, str) / (str, scalar) — AX = scalar elem,
// DX = str.ptr, CX = str.len.
// 24B convention mirrors the tagged-union return below; receive
// sites destructure off the same regs regardless of position.
if (rhs.kind == N_TUPLE) {
let v: *node = rhs.list;
if (v != nil) {
let v2: *node = v.next;
if (v2 != nil) {
cgexpr(c, v2);
emitline("\tPUSHQ\tAX\n");
cgexpr(c, v);
emitline("\tPOPQ\tDX\n");
let v0_is_str: bool = nodeisstr(c, v);
let v1_is_str: bool = nodeisstr(c, v2);
if ((v0_is_str || v1_is_str) && !(v0_is_str && v1_is_str)) {
let strn: *node = v;
let scaln: *node = v2;
if (v1_is_str) { strn = v2; scaln = v; };
cgexpr(c, scaln);
emitline("\tPUSHQ\tAX\n");
cgexpr(c, strn);
emitline("\tMOVQ\tBX, CX\n");
emitline("\tMOVQ\tAX, DX\n");
emitline("\tPOPQ\tAX\n");
} else {
cgexpr(c, v2);
emitline("\tPUSHQ\tAX\n");
cgexpr(c, v);
emitline("\tPOPQ\tDX\n");
};
} else {
cgexpr(c, v);
};
@@ -5984,6 +6214,50 @@ fn cglet(c: *cgen, n: *node) void = {
c.lastwasreturn = 0;
return;
};
// 24B tuple init for `let t: (scalar, str) = call()` /
// `let t: (str, scalar) = call()`. Per the AX:DX:CX return
// convention: AX = scalar elem, DX = str.ptr, CX = str.len.
// Layout is positional, so we route each register to the
// slot dictated by element type, not by AX/DX position.
if (n.lhs != nil) {
if (n.lhs.kind == N_TTUPLE) {
let p0: *node = n.lhs.list;
let p1: *node = nil;
if (p0 != nil) { p1 = p0.next; };
let s0_is_str: bool = isstrtyperaw(p0);
let s1_is_str: bool = isstrtyperaw(p1);
if (p0 != nil) {
if (p1 != nil) {
if (s0_is_str != s1_is_str) {
cgexpr(c, rhs);
if (s0_is_str) {
emitline("\tMOVQ\tDX, ");
emitoff(off: i64);
emitline("(BP)\n");
emitline("\tMOVQ\tCX, ");
emitoff((off + 8): i64);
emitline("(BP)\n");
emitline("\tMOVQ\tAX, ");
emitoff((off + 16): i64);
emitline("(BP)\n");
} else {
emitline("\tMOVQ\tAX, ");
emitoff(off: i64);
emitline("(BP)\n");
emitline("\tMOVQ\tDX, ");
emitoff((off + 8): i64);
emitline("(BP)\n");
emitline("\tMOVQ\tCX, ");
emitoff((off + 16): i64);
emitline("(BP)\n");
};
c.lastwasreturn = 0;
return;
};
};
};
};
};
// Array literal init: `let xs: [N]T = [a, b, c];` (or [_]T).
// Walk elements in declaration order, store each at off + i*esz
// using the right width for the element type. Trailing `...`
@@ -6256,6 +6530,109 @@ fn cgmassign(c: *cgen, n: *node) void = {
return;
};
// Multi-let from a tuple-returning call: `let n, s = call();` or
// `let (n, s) = call();`. wwstage has no checker, so each binding's
// type is taken from its explicit annotation (l.lhs) when present
// or inferred from the called fn's return-type tuple element.
//
// Per the AX:DX:CX return convention (mirrors C cgen N_MLET):
// (scalar, scalar) — AX → l0, DX → l1.
// (scalar, str) — AX → scalar slot, (DX, CX) → str slot
// as (.ptr, .len). Position-agnostic — the
// regs are routed by element type, not by AX/DX.
fn cgmlet(c: *cgen, n: *node) void = {
let rhs: *node = n.rhs;
if (rhs == nil) { return; };
let p0t: *node = nil;
let p1t: *node = nil;
if (rhs.kind == N_CALL) {
let callee: *node = rhs.lhs;
if (callee != nil) {
let cnm: str;
cnm.ptr = nil; cnm.len = 0;
if (callee.kind == N_IDENT) { cnm = callee.str; };
if (callee.kind == N_DOT) { cnm = callee.str; };
if (cnm.len > 0) {
let rt: *node = fnretlookup(c, cnm);
if (rt != nil) {
if (rt.kind == N_TTUPLE) {
p0t = rt.list;
if (p0t != nil) { p1t = p0t.next; };
};
};
};
};
};
let l0: *node = n.list;
let l1: *node = nil;
if (l0 != nil) { l1 = l0.next; };
let t0: *node = nil;
let t1: *node = nil;
if (l0 != nil) { t0 = l0.lhs; };
if (l1 != nil) { t1 = l1.lhs; };
if (t0 == nil) { t0 = p0t; };
if (t1 == nil) { t1 = p1t; };
let s0_is_str: bool = isstrtyperaw(t0);
let s1_is_str: bool = isstrtyperaw(t1);
cgexpr(c, rhs);
if (l0 != nil) {
if (l1 != nil) {
if (s0_is_str != s1_is_str) {
let sz0: i32 = 8;
let sz1: i32 = 8;
if (s0_is_str) { sz0 = 16; };
if (s1_is_str) { sz1 = 16; };
let off0: i32 = localadd(c, l0.str, sz0, t0);
let off1: i32 = localadd(c, l1.str, sz1, t1);
if (s0_is_str) {
emitline("\tMOVQ\tDX, ");
emitoff(off0: i64);
emitline("(BP)\n");
emitline("\tMOVQ\tCX, ");
emitoff((off0 + 8): i64);
emitline("(BP)\n");
emitline("\tMOVQ\tAX, ");
emitoff(off1: i64);
emitline("(BP)\n");
} else {
emitline("\tMOVQ\tAX, ");
emitoff(off0: i64);
emitline("(BP)\n");
emitline("\tMOVQ\tDX, ");
emitoff(off1: i64);
emitline("(BP)\n");
emitline("\tMOVQ\tCX, ");
emitoff((off1 + 8): i64);
emitline("(BP)\n");
};
c.lastwasreturn = 0;
return;
};
};
};
if (l0 != nil) {
let off: i32 = localadd(c, l0.str, 8, t0);
emitline("\tMOVQ\tAX, ");
emitoff(off: i64);
emitline("(BP)\n");
};
if (l1 != nil) {
let off: i32 = localadd(c, l1.str, 8, t1);
emitline("\tMOVQ\tDX, ");
emitoff(off: i64);
emitline("(BP)\n");
};
c.lastwasreturn = 0;
return;
};
fn cgbreak(c: *cgen, n: *node) void = {
if (c.looptop > 0) {
let lbl: str = c.loopendbuf[c.looptop - 1];
@@ -6318,6 +6695,54 @@ fn scanlocals(c: *cgen, n: *node) i32 = {
total += sz;
};
};
// Multi-let from a tuple-returning call: each binding's size
// comes from its annotated type (l.lhs) when present, else from
// the rhs call's return-tuple element type. Marking via
// scanseenmark also dedupes the recursive descent into n.list
// so each child isn't counted again at the default 8B.
if (n.kind == N_MLET) {
let p0t: *node = nil;
let p1t: *node = nil;
if (n.rhs != nil) {
if (n.rhs.kind == N_CALL) {
let callee: *node = n.rhs.lhs;
if (callee != nil) {
let cnm: str;
cnm.ptr = nil; cnm.len = 0;
if (callee.kind == N_IDENT) { cnm = callee.str; };
if (callee.kind == N_DOT) { cnm = callee.str; };
if (cnm.len > 0) {
let rt: *node = fnretlookup(c, cnm);
if (rt != nil) {
if (rt.kind == N_TTUPLE) {
p0t = rt.list;
if (p0t != nil) { p1t = p0t.next; };
};
};
};
};
};
};
let l: *node = n.list;
let pt: *node = p0t;
let bidx: i32 = 0;
for (l != nil) {
if (!scanseenmark(c, l.str)) {
let t: *node = l.lhs;
if (t == nil) {
if (bidx == 0) { t = p0t; };
if (bidx == 1) { t = p1t; };
};
let sz: i32 = 8;
if (t != nil) { sz = slotsize(c, t); };
if (sz < 8) { sz = 8; };
if ((sz & 7) != 0) { sz = (sz + 7) & ~7; };
total += sz;
};
l = l.next;
bidx += 1;
};
};
// Match-arm binding (`case let v: T => ...`) gets a slot too.
// Crucially we do NOT dedup these against c.locals: C cgen
// handles a match as an expression with a by-value locals copy,

11
selfhost/cmd/w6l/main.combined.ww
View File

@@ -1345,14 +1345,13 @@ export fn resolve(l: *lnk) i32 = {
for (r != nil) {
if (r.sym != nil) {
if (r.sym.defined == 0) {
let sym: *lsym = r.sym;
if (sym.isdyn == 0) {
if (r.sym.isdyn == 0) {
let so: *lso = l.sos;
for (so != nil) {
if (soprovides(so, sym.name) != 0) {
sym.isdyn = 1;
sym.dynlib = so;
sym.pltidx = l.dynn;
if (soprovides(so, r.sym.name) != 0) {
r.sym.isdyn = 1;
r.sym.dynlib = so;
r.sym.pltidx = l.dynn;
l.dynn += 1;
so = nil; // break
} else {

11
selfhost/cmd/w6l/pass.ww
View File

@@ -35,14 +35,13 @@ export fn resolve(l: *lnk) i32 = {
for (r != nil) {
if (r.sym != nil) {
if (r.sym.defined == 0) {
let sym: *lsym = r.sym;
if (sym.isdyn == 0) {
if (r.sym.isdyn == 0) {
let so: *lso = l.sos;
for (so != nil) {
if (soprovides(so, sym.name) != 0) {
sym.isdyn = 1;
sym.dynlib = so;
sym.pltidx = l.dynn;
if (soprovides(so, r.sym.name) != 0) {
r.sym.isdyn = 1;
r.sym.dynlib = so;
r.sym.pltidx = l.dynn;
l.dynn += 1;
so = nil; // break
} else {

48
selfhost/cmd/wcc/cgendecl.ww
View File

@@ -39,6 +39,54 @@ fn scanlocals(c: *cgen, n: *node) i32 = {
total += sz;
};
};
// Multi-let from a tuple-returning call: each binding's size
// comes from its annotated type (l.lhs) when present, else from
// the rhs call's return-tuple element type. Marking via
// scanseenmark also dedupes the recursive descent into n.list
// so each child isn't counted again at the default 8B.
if (n.kind == N_MLET) {
let p0t: *node = nil;
let p1t: *node = nil;
if (n.rhs != nil) {
if (n.rhs.kind == N_CALL) {
let callee: *node = n.rhs.lhs;
if (callee != nil) {
let cnm: str;
cnm.ptr = nil; cnm.len = 0;
if (callee.kind == N_IDENT) { cnm = callee.str; };
if (callee.kind == N_DOT) { cnm = callee.str; };
if (cnm.len > 0) {
let rt: *node = fnretlookup(c, cnm);
if (rt != nil) {
if (rt.kind == N_TTUPLE) {
p0t = rt.list;
if (p0t != nil) { p1t = p0t.next; };
};
};
};
};
};
};
let l: *node = n.list;
let pt: *node = p0t;
let bidx: i32 = 0;
for (l != nil) {
if (!scanseenmark(c, l.str)) {
let t: *node = l.lhs;
if (t == nil) {
if (bidx == 0) { t = p0t; };
if (bidx == 1) { t = p1t; };
};
let sz: i32 = 8;
if (t != nil) { sz = slotsize(c, t); };
if (sz < 8) { sz = 8; };
if ((sz & 7) != 0) { sz = (sz + 7) & ~7; };
total += sz;
};
l = l.next;
bidx += 1;
};
};
// Match-arm binding (`case let v: T => ...`) gets a slot too.
// Crucially we do NOT dedup these against c.locals: C cgen
// handles a match as an expression with a by-value locals copy,

108
selfhost/cmd/wcc/cgenexpr.ww
View File

@@ -419,6 +419,49 @@ fn cgdot(c: *cgen, n: *node) void = {
return;
};
};
// Hare-style tuple positional access: `t.0`, `t.1`.
// Walk the tuple element type list summing slotsize
// (matches the (scalar, str) init layout which puts
// the scalar in an 8B slot and the str in 16B). For
// a str element, load both halves into (AX, BX) so
// chains like `t.1.len` propagate correctly.
if (lkind == N_TTUPLE) {
let idx: i32 = fldnumidx(fld);
if (idx >= 0) {
let tp: *node = tn.list;
let foff: i32 = 0;
let i: i32 = 0;
for (i < idx) {
if (tp == nil) { i = idx; }
else {
foff += slotsize(c, tp);
tp = tp.next;
i += 1;
};
};
if (tp != nil) {
if (isstrtyperaw(tp)) {
emitline("\tMOVQ\t");
emitoff((lc.off + foff + 0): i64);
emitline("(BP), AX\n");
emitline("\tMOVQ\t");
emitoff((lc.off + foff + 8): i64);
emitline("(BP), BX\n");
return;
};
let sz: i32 = slotsize(c, tp);
let op: str = "MOVQ";
if (sz == 1) { op = "MOVZBQ"; }
else { if (sz == 4) { op = "MOVL"; }; };
emitline("\t");
emitline(op);
emitline("\t");
emitoff((lc.off + foff): i64);
emitline("(BP), AX\n");
return;
};
};
};
// str/slice pseudo-fields .ptr/.len/.cap on a
// direct local: load at slot+delta.
let delta: i32 = -1;
@@ -1049,6 +1092,71 @@ fn cgassign(c: *cgen, n: *node) void = {
};
};
};
// Chained `<expr>.field = v` where `<expr>` itself is a chain
// of dots resolving to a *struct. Mirrors the C cgen branch
// added to close trap 1 (cmd/w6c/cgen.c). Without this, only
// `local.field = v` and `local.fieldptr.field = v` get wired
// (the latter through the IDENT-base branch above) — chains
// like `s.last.snext = sy` (lib/ww/sym.ww) silently emit no
// store. Only plain `=` is wired here; chained compound on a
// pointer-field hasn't surfaced.
if (lhs != nil) {
if (lhs.kind == N_DOT) {
let base: *node = lhs.lhs;
let fld: str = lhs.str;
if (base != nil) {
if (base.kind == N_DOT) {
let innert: *node = dotinnerstructptr(c, base);
if (innert != nil) {
let sname: str = innert.str;
let si: *structinfo = structlookup(c, sname);
if (si != nil) {
let fi: *fieldinfo = si.fields;
for (fi != nil) {
if (streq(fi.fname, fld)) {
if (n.op == TK_ASSIGN) {
if (isstrtype(c, fi.tnode)) {
// str rhs: AX=ptr, BX=len.
// Stash both, then load
// the struct ptr into CX
// and write both halves.
cgexpr(c, n.rhs);
emitline("\tPUSHQ\tBX\n");
emitline("\tPUSHQ\tAX\n");
cgexpr(c, base);
emitline("\tMOVQ\tAX, CX\n");
emitline("\tPOPQ\tAX\n");
emitline("\tPOPQ\tBX\n");
emitline("\tMOVQ\tAX, ");
emitdispreg(fi.foff: i64, "CX");
emitline("\n");
emitline("\tMOVQ\tBX, ");
emitdispreg((fi.foff + 8): i64, "CX");
emitline("\n");
return;
};
cgexpr(c, n.rhs);
emitline("\tPUSHQ\tAX\n");
cgexpr(c, base);
emitline("\tMOVQ\tAX, BX\n");
emitline("\tPOPQ\tAX\n");
let sop: str = fieldstoreop(fi);
emitline("\t");
emitline(sop);
emitline("\tAX, ");
emitdispreg(fi.foff: i64, "BX");
emitline("\n");
return;
};
};
fi = fi.finext;
};
};
};
};
};
};
};
// Local-ident target — plain `=` and the simple compound
// forms (+= -= *= /=); other compounds fall back to
// "evaluate rhs, replace". Mirrors C cgen's IDENT-assign path.

180
selfhost/cmd/wcc/cgenstmt.ww
View File

@@ -36,6 +36,8 @@ fn cgstmt(c: *cgen, n: *node) void = {
if (k == N_MASSIGN) { cgmassign(c, n); return; };
if (k == N_MLET) { cgmlet(c, n); return; };
if (k == N_BREAK) { cgbreak(c, n); return; };
if (k == N_CONTINUE) { cgcontinue(c, n); return; };
@@ -54,18 +56,35 @@ fn cgblock(c: *cgen, n: *node) void = {
fn cgreturn(c: *cgen, n: *node) void = {
let rhs: *node = n.lhs;
if (rhs != nil) {
// Tuple return `return a, b;` — pack as (AX=v0, DX=v1).
// Matches C cgen: evaluate v1 first (PUSHQ), then v0
// into AX, then POPQ DX. End state: AX = v0, DX = v1.
// Tuple return `return a, b;`:
// (scalar, scalar) — AX = v0, DX = v1.
// (scalar, str) / (str, scalar) — AX = scalar elem,
// DX = str.ptr, CX = str.len.
// 24B convention mirrors the tagged-union return below; receive
// sites destructure off the same regs regardless of position.
if (rhs.kind == N_TUPLE) {
let v: *node = rhs.list;
if (v != nil) {
let v2: *node = v.next;
if (v2 != nil) {
cgexpr(c, v2);
emitline("\tPUSHQ\tAX\n");
cgexpr(c, v);
emitline("\tPOPQ\tDX\n");
let v0_is_str: bool = nodeisstr(c, v);
let v1_is_str: bool = nodeisstr(c, v2);
if ((v0_is_str || v1_is_str) && !(v0_is_str && v1_is_str)) {
let strn: *node = v;
let scaln: *node = v2;
if (v1_is_str) { strn = v2; scaln = v; };
cgexpr(c, scaln);
emitline("\tPUSHQ\tAX\n");
cgexpr(c, strn);
emitline("\tMOVQ\tBX, CX\n");
emitline("\tMOVQ\tAX, DX\n");
emitline("\tPOPQ\tAX\n");
} else {
cgexpr(c, v2);
emitline("\tPUSHQ\tAX\n");
cgexpr(c, v);
emitline("\tPOPQ\tDX\n");
};
} else {
cgexpr(c, v);
};
@@ -187,6 +206,50 @@ fn cglet(c: *cgen, n: *node) void = {
c.lastwasreturn = 0;
return;
};
// 24B tuple init for `let t: (scalar, str) = call()` /
// `let t: (str, scalar) = call()`. Per the AX:DX:CX return
// convention: AX = scalar elem, DX = str.ptr, CX = str.len.
// Layout is positional, so we route each register to the
// slot dictated by element type, not by AX/DX position.
if (n.lhs != nil) {
if (n.lhs.kind == N_TTUPLE) {
let p0: *node = n.lhs.list;
let p1: *node = nil;
if (p0 != nil) { p1 = p0.next; };
let s0_is_str: bool = isstrtyperaw(p0);
let s1_is_str: bool = isstrtyperaw(p1);
if (p0 != nil) {
if (p1 != nil) {
if (s0_is_str != s1_is_str) {
cgexpr(c, rhs);
if (s0_is_str) {
emitline("\tMOVQ\tDX, ");
emitoff(off: i64);
emitline("(BP)\n");
emitline("\tMOVQ\tCX, ");
emitoff((off + 8): i64);
emitline("(BP)\n");
emitline("\tMOVQ\tAX, ");
emitoff((off + 16): i64);
emitline("(BP)\n");
} else {
emitline("\tMOVQ\tAX, ");
emitoff(off: i64);
emitline("(BP)\n");
emitline("\tMOVQ\tDX, ");
emitoff((off + 8): i64);
emitline("(BP)\n");
emitline("\tMOVQ\tCX, ");
emitoff((off + 16): i64);
emitline("(BP)\n");
};
c.lastwasreturn = 0;
return;
};
};
};
};
};
// Array literal init: `let xs: [N]T = [a, b, c];` (or [_]T).
// Walk elements in declaration order, store each at off + i*esz
// using the right width for the element type. Trailing `...`
@@ -459,6 +522,109 @@ fn cgmassign(c: *cgen, n: *node) void = {
return;
};
// Multi-let from a tuple-returning call: `let n, s = call();` or
// `let (n, s) = call();`. wwstage has no checker, so each binding's
// type is taken from its explicit annotation (l.lhs) when present
// or inferred from the called fn's return-type tuple element.
//
// Per the AX:DX:CX return convention (mirrors C cgen N_MLET):
// (scalar, scalar) — AX → l0, DX → l1.
// (scalar, str) — AX → scalar slot, (DX, CX) → str slot
// as (.ptr, .len). Position-agnostic — the
// regs are routed by element type, not by AX/DX.
fn cgmlet(c: *cgen, n: *node) void = {
let rhs: *node = n.rhs;
if (rhs == nil) { return; };
let p0t: *node = nil;
let p1t: *node = nil;
if (rhs.kind == N_CALL) {
let callee: *node = rhs.lhs;
if (callee != nil) {
let cnm: str;
cnm.ptr = nil; cnm.len = 0;
if (callee.kind == N_IDENT) { cnm = callee.str; };
if (callee.kind == N_DOT) { cnm = callee.str; };
if (cnm.len > 0) {
let rt: *node = fnretlookup(c, cnm);
if (rt != nil) {
if (rt.kind == N_TTUPLE) {
p0t = rt.list;
if (p0t != nil) { p1t = p0t.next; };
};
};
};
};
};
let l0: *node = n.list;
let l1: *node = nil;
if (l0 != nil) { l1 = l0.next; };
let t0: *node = nil;
let t1: *node = nil;
if (l0 != nil) { t0 = l0.lhs; };
if (l1 != nil) { t1 = l1.lhs; };
if (t0 == nil) { t0 = p0t; };
if (t1 == nil) { t1 = p1t; };
let s0_is_str: bool = isstrtyperaw(t0);
let s1_is_str: bool = isstrtyperaw(t1);
cgexpr(c, rhs);
if (l0 != nil) {
if (l1 != nil) {
if (s0_is_str != s1_is_str) {
let sz0: i32 = 8;
let sz1: i32 = 8;
if (s0_is_str) { sz0 = 16; };
if (s1_is_str) { sz1 = 16; };
let off0: i32 = localadd(c, l0.str, sz0, t0);
let off1: i32 = localadd(c, l1.str, sz1, t1);
if (s0_is_str) {
emitline("\tMOVQ\tDX, ");
emitoff(off0: i64);
emitline("(BP)\n");
emitline("\tMOVQ\tCX, ");
emitoff((off0 + 8): i64);
emitline("(BP)\n");
emitline("\tMOVQ\tAX, ");
emitoff(off1: i64);
emitline("(BP)\n");
} else {
emitline("\tMOVQ\tAX, ");
emitoff(off0: i64);
emitline("(BP)\n");
emitline("\tMOVQ\tDX, ");
emitoff(off1: i64);
emitline("(BP)\n");
emitline("\tMOVQ\tCX, ");
emitoff((off1 + 8): i64);
emitline("(BP)\n");
};
c.lastwasreturn = 0;
return;
};
};
};
if (l0 != nil) {
let off: i32 = localadd(c, l0.str, 8, t0);
emitline("\tMOVQ\tAX, ");
emitoff(off: i64);
emitline("(BP)\n");
};
if (l1 != nil) {
let off: i32 = localadd(c, l1.str, 8, t1);
emitline("\tMOVQ\tDX, ");
emitoff(off: i64);
emitline("(BP)\n");
};
c.lastwasreturn = 0;
return;
};
fn cgbreak(c: *cgen, n: *node) void = {
if (c.looptop > 0) {
let lbl: str = c.loopendbuf[c.looptop - 1];

31
selfhost/cmd/wcc/cgenutil.ww
View File

@@ -599,6 +599,23 @@ fn structlookup(c: *cgen, name: str) *structinfo = {
// primsize — size in bytes of a primitive type name (or 0 if not
// recognised as a primitive — the caller falls back to other paths).
// fldnumidx — parse a tuple field name like "0" / "1" / "12" into an
// index, or -1 if not all-digits. Used by cgdot to dispatch
// `t.0` / `t.1` against an N_TTUPLE local without pulling in strconv.
fn fldnumidx(s: str) i32 = {
if (s.len == 0) { return -1; };
let r: i32 = 0;
let i: i32 = 0;
for (i < s.len) {
let b: u8 = s[i];
if (b < 48u8) { return -1; };
if (b > 57u8) { return -1; };
r = r * 10 + ((b - 48u8): i32);
i += 1;
};
return r;
};
fn primsize(name: str) i32 = {
if (streq(name, "u8")) { return 1; };
if (streq(name, "i8")) { return 1; };
@@ -672,7 +689,19 @@ fn slotsize(c: *cgen, typn: *node) i32 = {
if (k == N_TFN) { return 8; };
if (k == N_TCHAN) { return 8; };
if (k == N_TSLICE) { return 24; };
if (k == N_TTUPLE) { return 16; };
if (k == N_TTUPLE) {
// Sum element sizes. Mirrors C cgen which uses raw type
// sizes; padding to 8 happens inside slotsize for primitives,
// so a `(i64, str)` resolves to 8 + 16 = 24 (matches the C
// cgen 24B init / positional-access layout).
let total: i32 = 0;
let p: *node = typn.list;
for (p != nil) {
total += slotsize(c, p);
p = p.next;
};
return total;
};
if (k == N_TTAGGED){ return 24; };
if (k == N_TNAME) {
let nm: str = typn.str;

447
selfhost/cmd/wwdump/main.combined.ww
View File

@@ -2251,9 +2251,17 @@ fn parsepostfix(p: *parser, lhs: *node) *node = {
advance(p);
let n: *node = newnode(p.a, N_DOT, pf, pl, pc);
n.lhs = cur;
let id: str;
expectident(p, &id);
n.str = id;
// Hare-style tuple field access: `t.0`, `t.1`. The
// numeric literal becomes the field name string so the
// cgen tuple-positional path matches `cmd/wcc/parse.c`.
if (p.curkind == TK_INT) {
n.str = p.curtext;
advance(p);
} else {
let id: str;
expectident(p, &id);
n.str = id;
};
cur = n;
continue;
};
@@ -2374,6 +2382,42 @@ fn parseletlocal(p: *parser) *node = {
let is_const: i32 = 0;
if (p.curkind == TK_CONST) { is_const = 1; };
advance(p);
// Hare-style tuple destructure: `let (a, b) = expr;`.
// Types are optional per binding (matches C parser; Hare itself
// doesn't allow types here, but cmd/wcc/parse.c does).
if (p.curkind == TK_LPAREN) {
advance(p);
let m: *node = newnode(p.a, N_MLET, pf, pl, pc);
let head: *node = nil;
let tail: *node = nil;
for (true) {
let lpf: str = p.curfile;
let lpl: i32 = p.curline;
let lpc: i32 = p.curcol;
let l: *node = newnode(p.a, N_LET, lpf, lpl, lpc);
let id: str;
expectbindname(p, &id);
l.str = id;
if (accepttok(p, TK_COLON)) { l.lhs = parsetype(p); };
if (head == nil) { head = l; }
else { tail.next = l; };
tail = l;
if (!accepttok(p, TK_COMMA)) { break; };
};
expecttok(p, TK_RPAREN, "expected ')' in let destructure");
expecttok(p, TK_ASSIGN, "expected '=' after let destructure");
m.rhs = parseexpr(p);
expecttok(p, TK_SEMI, "expected ';' after let");
m.list = head;
if (is_const != 0) {
m.op = TK_CONST;
let lc: *node = head;
for (lc != nil) { lc.op = TK_CONST; lc = lc.next; };
};
return m;
};
let n: *node = newnode(p.a, N_LET, pf, pl, pc);
let id: str;
expectbindname(p, &id);
@@ -2381,6 +2425,36 @@ fn parseletlocal(p: *parser) *node = {
if (accepttok(p, TK_COLON)) {
n.lhs = parsetype(p);
};
// Comma-multi-let: `let n, s = call();` (ww extension over Hare).
// Collects (name, type) pairs, then '=' rhs. Each binding gets
// its own N_LET; the wrapping N_MLET carries the rhs.
if (p.curkind == TK_COMMA) {
let m: *node = newnode(p.a, N_MLET, pf, pl, pc);
let head: *node = n;
let tail: *node = n;
for (accepttok(p, TK_COMMA)) {
let lpf: str = p.curfile;
let lpl: i32 = p.curline;
let lpc: i32 = p.curcol;
let l: *node = newnode(p.a, N_LET, lpf, lpl, lpc);
let id2: str;
expectbindname(p, &id2);
l.str = id2;
if (accepttok(p, TK_COLON)) { l.lhs = parsetype(p); };
tail.next = l;
tail = l;
};
expecttok(p, TK_ASSIGN, "expected '=' after let names");
m.rhs = parseexpr(p);
expecttok(p, TK_SEMI, "expected ';' after let");
m.list = head;
if (is_const != 0) {
m.op = TK_CONST;
let lc: *node = head;
for (lc != nil) { lc.op = TK_CONST; lc = lc.next; };
};
return m;
};
if (accepttok(p, TK_ASSIGN)) {
n.rhs = parseexpr(p);
};
@@ -4368,6 +4442,23 @@ fn structlookup(c: *cgen, name: str) *structinfo = {
// primsize — size in bytes of a primitive type name (or 0 if not
// recognised as a primitive — the caller falls back to other paths).
// fldnumidx — parse a tuple field name like "0" / "1" / "12" into an
// index, or -1 if not all-digits. Used by cgdot to dispatch
// `t.0` / `t.1` against an N_TTUPLE local without pulling in strconv.
fn fldnumidx(s: str) i32 = {
if (s.len == 0) { return -1; };
let r: i32 = 0;
let i: i32 = 0;
for (i < s.len) {
let b: u8 = s[i];
if (b < 48u8) { return -1; };
if (b > 57u8) { return -1; };
r = r * 10 + ((b - 48u8): i32);
i += 1;
};
return r;
};
fn primsize(name: str) i32 = {
if (streq(name, "u8")) { return 1; };
if (streq(name, "i8")) { return 1; };
@@ -4441,7 +4532,19 @@ fn slotsize(c: *cgen, typn: *node) i32 = {
if (k == N_TFN) { return 8; };
if (k == N_TCHAN) { return 8; };
if (k == N_TSLICE) { return 24; };
if (k == N_TTUPLE) { return 16; };
if (k == N_TTUPLE) {
// Sum element sizes. Mirrors C cgen which uses raw type
// sizes; padding to 8 happens inside slotsize for primitives,
// so a `(i64, str)` resolves to 8 + 16 = 24 (matches the C
// cgen 24B init / positional-access layout).
let total: i32 = 0;
let p: *node = typn.list;
for (p != nil) {
total += slotsize(c, p);
p = p.next;
};
return total;
};
if (k == N_TTAGGED){ return 24; };
if (k == N_TNAME) {
let nm: str = typn.str;
@@ -5100,6 +5203,49 @@ fn cgdot(c: *cgen, n: *node) void = {
return;
};
};
// Hare-style tuple positional access: `t.0`, `t.1`.
// Walk the tuple element type list summing slotsize
// (matches the (scalar, str) init layout which puts
// the scalar in an 8B slot and the str in 16B). For
// a str element, load both halves into (AX, BX) so
// chains like `t.1.len` propagate correctly.
if (lkind == N_TTUPLE) {
let idx: i32 = fldnumidx(fld);
if (idx >= 0) {
let tp: *node = tn.list;
let foff: i32 = 0;
let i: i32 = 0;
for (i < idx) {
if (tp == nil) { i = idx; }
else {
foff += slotsize(c, tp);
tp = tp.next;
i += 1;
};
};
if (tp != nil) {
if (isstrtyperaw(tp)) {
emitline("\tMOVQ\t");
emitoff((lc.off + foff + 0): i64);
emitline("(BP), AX\n");
emitline("\tMOVQ\t");
emitoff((lc.off + foff + 8): i64);
emitline("(BP), BX\n");
return;
};
let sz: i32 = slotsize(c, tp);
let op: str = "MOVQ";
if (sz == 1) { op = "MOVZBQ"; }
else { if (sz == 4) { op = "MOVL"; }; };
emitline("\t");
emitline(op);
emitline("\t");
emitoff((lc.off + foff): i64);
emitline("(BP), AX\n");
return;
};
};
};
// str/slice pseudo-fields .ptr/.len/.cap on a
// direct local: load at slot+delta.
let delta: i32 = -1;
@@ -5730,6 +5876,71 @@ fn cgassign(c: *cgen, n: *node) void = {
};
};
};
// Chained `<expr>.field = v` where `<expr>` itself is a chain
// of dots resolving to a *struct. Mirrors the C cgen branch
// added to close trap 1 (cmd/w6c/cgen.c). Without this, only
// `local.field = v` and `local.fieldptr.field = v` get wired
// (the latter through the IDENT-base branch above) — chains
// like `s.last.snext = sy` (lib/ww/sym.ww) silently emit no
// store. Only plain `=` is wired here; chained compound on a
// pointer-field hasn't surfaced.
if (lhs != nil) {
if (lhs.kind == N_DOT) {
let base: *node = lhs.lhs;
let fld: str = lhs.str;
if (base != nil) {
if (base.kind == N_DOT) {
let innert: *node = dotinnerstructptr(c, base);
if (innert != nil) {
let sname: str = innert.str;
let si: *structinfo = structlookup(c, sname);
if (si != nil) {
let fi: *fieldinfo = si.fields;
for (fi != nil) {
if (streq(fi.fname, fld)) {
if (n.op == TK_ASSIGN) {
if (isstrtype(c, fi.tnode)) {
// str rhs: AX=ptr, BX=len.
// Stash both, then load
// the struct ptr into CX
// and write both halves.
cgexpr(c, n.rhs);
emitline("\tPUSHQ\tBX\n");
emitline("\tPUSHQ\tAX\n");
cgexpr(c, base);
emitline("\tMOVQ\tAX, CX\n");
emitline("\tPOPQ\tAX\n");
emitline("\tPOPQ\tBX\n");
emitline("\tMOVQ\tAX, ");
emitdispreg(fi.foff: i64, "CX");
emitline("\n");
emitline("\tMOVQ\tBX, ");
emitdispreg((fi.foff + 8): i64, "CX");
emitline("\n");
return;
};
cgexpr(c, n.rhs);
emitline("\tPUSHQ\tAX\n");
cgexpr(c, base);
emitline("\tMOVQ\tAX, BX\n");
emitline("\tPOPQ\tAX\n");
let sop: str = fieldstoreop(fi);
emitline("\t");
emitline(sop);
emitline("\tAX, ");
emitdispreg(fi.foff: i64, "BX");
emitline("\n");
return;
};
};
fi = fi.finext;
};
};
};
};
};
};
};
// Local-ident target — plain `=` and the simple compound
// forms (+= -= *= /=); other compounds fall back to
// "evaluate rhs, replace". Mirrors C cgen's IDENT-assign path.
@@ -5833,6 +6044,8 @@ fn cgstmt(c: *cgen, n: *node) void = {
if (k == N_MASSIGN) { cgmassign(c, n); return; };
if (k == N_MLET) { cgmlet(c, n); return; };
if (k == N_BREAK) { cgbreak(c, n); return; };
if (k == N_CONTINUE) { cgcontinue(c, n); return; };
@@ -5851,18 +6064,35 @@ fn cgblock(c: *cgen, n: *node) void = {
fn cgreturn(c: *cgen, n: *node) void = {
let rhs: *node = n.lhs;
if (rhs != nil) {
// Tuple return `return a, b;` — pack as (AX=v0, DX=v1).
// Matches C cgen: evaluate v1 first (PUSHQ), then v0
// into AX, then POPQ DX. End state: AX = v0, DX = v1.
// Tuple return `return a, b;`:
// (scalar, scalar) — AX = v0, DX = v1.
// (scalar, str) / (str, scalar) — AX = scalar elem,
// DX = str.ptr, CX = str.len.
// 24B convention mirrors the tagged-union return below; receive
// sites destructure off the same regs regardless of position.
if (rhs.kind == N_TUPLE) {
let v: *node = rhs.list;
if (v != nil) {
let v2: *node = v.next;
if (v2 != nil) {
cgexpr(c, v2);
emitline("\tPUSHQ\tAX\n");
cgexpr(c, v);
emitline("\tPOPQ\tDX\n");
let v0_is_str: bool = nodeisstr(c, v);
let v1_is_str: bool = nodeisstr(c, v2);
if ((v0_is_str || v1_is_str) && !(v0_is_str && v1_is_str)) {
let strn: *node = v;
let scaln: *node = v2;
if (v1_is_str) { strn = v2; scaln = v; };
cgexpr(c, scaln);
emitline("\tPUSHQ\tAX\n");
cgexpr(c, strn);
emitline("\tMOVQ\tBX, CX\n");
emitline("\tMOVQ\tAX, DX\n");
emitline("\tPOPQ\tAX\n");
} else {
cgexpr(c, v2);
emitline("\tPUSHQ\tAX\n");
cgexpr(c, v);
emitline("\tPOPQ\tDX\n");
};
} else {
cgexpr(c, v);
};
@@ -5984,6 +6214,50 @@ fn cglet(c: *cgen, n: *node) void = {
c.lastwasreturn = 0;
return;
};
// 24B tuple init for `let t: (scalar, str) = call()` /
// `let t: (str, scalar) = call()`. Per the AX:DX:CX return
// convention: AX = scalar elem, DX = str.ptr, CX = str.len.
// Layout is positional, so we route each register to the
// slot dictated by element type, not by AX/DX position.
if (n.lhs != nil) {
if (n.lhs.kind == N_TTUPLE) {
let p0: *node = n.lhs.list;
let p1: *node = nil;
if (p0 != nil) { p1 = p0.next; };
let s0_is_str: bool = isstrtyperaw(p0);
let s1_is_str: bool = isstrtyperaw(p1);
if (p0 != nil) {
if (p1 != nil) {
if (s0_is_str != s1_is_str) {
cgexpr(c, rhs);
if (s0_is_str) {
emitline("\tMOVQ\tDX, ");
emitoff(off: i64);
emitline("(BP)\n");
emitline("\tMOVQ\tCX, ");
emitoff((off + 8): i64);
emitline("(BP)\n");
emitline("\tMOVQ\tAX, ");
emitoff((off + 16): i64);
emitline("(BP)\n");
} else {
emitline("\tMOVQ\tAX, ");
emitoff(off: i64);
emitline("(BP)\n");
emitline("\tMOVQ\tDX, ");
emitoff((off + 8): i64);
emitline("(BP)\n");
emitline("\tMOVQ\tCX, ");
emitoff((off + 16): i64);
emitline("(BP)\n");
};
c.lastwasreturn = 0;
return;
};
};
};
};
};
// Array literal init: `let xs: [N]T = [a, b, c];` (or [_]T).
// Walk elements in declaration order, store each at off + i*esz
// using the right width for the element type. Trailing `...`
@@ -6256,6 +6530,109 @@ fn cgmassign(c: *cgen, n: *node) void = {
return;
};
// Multi-let from a tuple-returning call: `let n, s = call();` or
// `let (n, s) = call();`. wwstage has no checker, so each binding's
// type is taken from its explicit annotation (l.lhs) when present
// or inferred from the called fn's return-type tuple element.
//
// Per the AX:DX:CX return convention (mirrors C cgen N_MLET):
// (scalar, scalar) — AX → l0, DX → l1.
// (scalar, str) — AX → scalar slot, (DX, CX) → str slot
// as (.ptr, .len). Position-agnostic — the
// regs are routed by element type, not by AX/DX.
fn cgmlet(c: *cgen, n: *node) void = {
let rhs: *node = n.rhs;
if (rhs == nil) { return; };
let p0t: *node = nil;
let p1t: *node = nil;
if (rhs.kind == N_CALL) {
let callee: *node = rhs.lhs;
if (callee != nil) {
let cnm: str;
cnm.ptr = nil; cnm.len = 0;
if (callee.kind == N_IDENT) { cnm = callee.str; };
if (callee.kind == N_DOT) { cnm = callee.str; };
if (cnm.len > 0) {
let rt: *node = fnretlookup(c, cnm);
if (rt != nil) {
if (rt.kind == N_TTUPLE) {
p0t = rt.list;
if (p0t != nil) { p1t = p0t.next; };
};
};
};
};
};
let l0: *node = n.list;
let l1: *node = nil;
if (l0 != nil) { l1 = l0.next; };
let t0: *node = nil;
let t1: *node = nil;
if (l0 != nil) { t0 = l0.lhs; };
if (l1 != nil) { t1 = l1.lhs; };
if (t0 == nil) { t0 = p0t; };
if (t1 == nil) { t1 = p1t; };
let s0_is_str: bool = isstrtyperaw(t0);
let s1_is_str: bool = isstrtyperaw(t1);
cgexpr(c, rhs);
if (l0 != nil) {
if (l1 != nil) {
if (s0_is_str != s1_is_str) {
let sz0: i32 = 8;
let sz1: i32 = 8;
if (s0_is_str) { sz0 = 16; };
if (s1_is_str) { sz1 = 16; };
let off0: i32 = localadd(c, l0.str, sz0, t0);
let off1: i32 = localadd(c, l1.str, sz1, t1);
if (s0_is_str) {
emitline("\tMOVQ\tDX, ");
emitoff(off0: i64);
emitline("(BP)\n");
emitline("\tMOVQ\tCX, ");
emitoff((off0 + 8): i64);
emitline("(BP)\n");
emitline("\tMOVQ\tAX, ");
emitoff(off1: i64);
emitline("(BP)\n");
} else {
emitline("\tMOVQ\tAX, ");
emitoff(off0: i64);
emitline("(BP)\n");
emitline("\tMOVQ\tDX, ");
emitoff(off1: i64);
emitline("(BP)\n");
emitline("\tMOVQ\tCX, ");
emitoff((off1 + 8): i64);
emitline("(BP)\n");
};
c.lastwasreturn = 0;
return;
};
};
};
if (l0 != nil) {
let off: i32 = localadd(c, l0.str, 8, t0);
emitline("\tMOVQ\tAX, ");
emitoff(off: i64);
emitline("(BP)\n");
};
if (l1 != nil) {
let off: i32 = localadd(c, l1.str, 8, t1);
emitline("\tMOVQ\tDX, ");
emitoff(off: i64);
emitline("(BP)\n");
};
c.lastwasreturn = 0;
return;
};
fn cgbreak(c: *cgen, n: *node) void = {
if (c.looptop > 0) {
let lbl: str = c.loopendbuf[c.looptop - 1];
@@ -6318,6 +6695,54 @@ fn scanlocals(c: *cgen, n: *node) i32 = {
total += sz;
};
};
// Multi-let from a tuple-returning call: each binding's size
// comes from its annotated type (l.lhs) when present, else from
// the rhs call's return-tuple element type. Marking via
// scanseenmark also dedupes the recursive descent into n.list
// so each child isn't counted again at the default 8B.
if (n.kind == N_MLET) {
let p0t: *node = nil;
let p1t: *node = nil;
if (n.rhs != nil) {
if (n.rhs.kind == N_CALL) {
let callee: *node = n.rhs.lhs;
if (callee != nil) {
let cnm: str;
cnm.ptr = nil; cnm.len = 0;
if (callee.kind == N_IDENT) { cnm = callee.str; };
if (callee.kind == N_DOT) { cnm = callee.str; };
if (cnm.len > 0) {
let rt: *node = fnretlookup(c, cnm);
if (rt != nil) {
if (rt.kind == N_TTUPLE) {
p0t = rt.list;
if (p0t != nil) { p1t = p0t.next; };
};
};
};
};
};
};
let l: *node = n.list;
let pt: *node = p0t;
let bidx: i32 = 0;
for (l != nil) {
if (!scanseenmark(c, l.str)) {
let t: *node = l.lhs;
if (t == nil) {
if (bidx == 0) { t = p0t; };
if (bidx == 1) { t = p1t; };
};
let sz: i32 = 8;
if (t != nil) { sz = slotsize(c, t); };
if (sz < 8) { sz = 8; };
if ((sz & 7) != 0) { sz = (sz + 7) & ~7; };
total += sz;
};
l = l.next;
bidx += 1;
};
};
// Match-arm binding (`case let v: T => ...`) gets a slot too.
// Crucially we do NOT dedup these against c.locals: C cgen
// handles a match as an expression with a by-value locals copy,

63
test/wcc/700_e2e.c
View File

@@ -806,6 +806,69 @@ static const struct row rows[] = {
" };\n"
" return acc;\n"
"};", 16 }, /* 3 + 3 + len(\"no newline\")=10 */
/* `(scalar, str)` tuple return: AX:DX:CX convention extends the
* tagged-union ABI. AX = scalar, DX = str.ptr, CX = str.len.
* Receive sites destructure off the same regs regardless of
* positional order. Without the fix, len was lost (only AX:DX
* returned), every receive shape gave garbage. */
{ "fn split() (i64, str) = { return 42, \"hello\"; };\n"
"fn main() i32 = {\n"
" let n, s = split();\n"
" return (n: i32) + (s.len: i32);\n"
"};", 47 },
{ "fn split() (str, i64) = { return \"hello\", 42; };\n"
"fn main() i32 = {\n"
" let s, n = split();\n"
" return (n: i32) + (s.len: i32);\n"
"};", 47 },
{ "fn split() (i64, str) = { return 42, \"hello\"; };\n"
"fn main() i32 = {\n"
" let t: (i64, str) = split();\n"
" return (t.0: i32) + (t.1.len: i32);\n"
"};", 47 },
/* Hare-style paren tuple-destructure with str element */
{ "fn split() (i64, str) = { return 42, \"hello\"; };\n"
"fn main() i32 = {\n"
" let (n, s) = split();\n"
" return (n: i32) + (s.len: i32);\n"
"};", 47 },
/* Chained field write through a pointer field: `r.sym.flag = v`
* where `r.sym: *T`. The cgen must evaluate the inner pointer,
* then store at *(ptr + field.offset). Without the fix, the
* single-level N_IDENT-base path doesn't fire (base is itself
* an N_DOT) and the assignment silently emits no instructions.
* Compound op + 1-byte field + 3-level chain all exercised. */
{ "type inner = struct { tag: u8, pad: u8, flag: i32 };\n"
"type outer = struct { sym: *inner };\n"
"fn main() i32 = {\n"
" let i: inner = inner { tag = 0u8, pad = 0u8, flag = 10 };\n"
" let r: outer = outer { sym = &i };\n"
" r.sym.flag += 32;\n"
" r.sym.tag = 5u8;\n"
" return r.sym.flag + (r.sym.tag: i32);\n"
"};", 47 },
{ "type leaf = struct { v: i32 };\n"
"type mid = struct { l: *leaf };\n"
"type top = struct { m: *mid };\n"
"fn main() i32 = {\n"
" let lf: leaf = leaf { v = 0 };\n"
" let md: mid = mid { l = &lf };\n"
" let tp: top = top { m = &md };\n"
" tp.m.l.v = 99;\n"
" return tp.m.l.v;\n"
"};", 99 },
/* `def NAME: str = \"lit\"` field access. The Sdef has no stack
* slot, so .len/.ptr must inline the literal length / strlit
* address; without the fix, .len reads BP+8 (return-address slot)
* as garbage. */
{ "def MSG: str = \"hello world\";\n"
"fn main() i32 = { return MSG.len: i32; };", 11 },
{ "use os;\n"
"def GREETING: str = \"hi\\n\";\n"
"fn main() i32 = {\n"
" os.write(1, GREETING.ptr, GREETING.len: u64);\n"
" return GREETING.len: i32;\n"
"};", 3 },
{ NULL, 0 }
};