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selfhost+cstage+test: graduate alias-chain unwrap to transitive (#22)

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Single-peel TY_NAMED.under bottoms out at the inner alias when
chain length is 2+, surfaces in two stages with different
mechanisms: cstage's gates inline `if (t->kind == TY_NAMED)
t = t->under` at every callsite (cgreturn, cglet sizing, cgexpr
N_DOT, cgassign N_DOT, cg_sret_retsize) — graduated to a
while-loop via new type_chase_named helper across 11 sites.
wwstage routes all field-walks through structlookup, which
registers only direct struct definitions (not aliases) — missing
the alias-recurse fallback. New structlookupchain helper mirrors
slotsize's N_TARRAY arm precedent; sretretsize + 4 cgenexpr.ww
sites route through it. Splitting would either land cstage
without unblocking wwstage's strings.tokenize wrapper shape
(rule 10 byte-id regression) or land wwstage without cstage
gate parity (breaking 995 self-rebuild). 756 sentinel exercises
4 rows × cstage RC + wwstage RC + byte-id = 12 fixtures; pre-fix
rows 2 + 4 (slice-fields single alias, i32 double alias) fail
on both RC and byte-id. The ~67 cstage / ~26 wwstage candidate
sibling sites are #17-style structural-close follow-up; this
commit fixes the immediate strings.tokenize-wrapper blockers.
This commit is contained in:
Hojun-Cho
2026-05-19 15:09:57 +09:00
parent 7e1b681701
commit a1d9f36d11
7 changed files with 513 additions and 40 deletions
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7
Makefile
View File

@@ -290,6 +290,7 @@ TESTS = $(BIN)/test_smoke $(BIN)/test_lex $(BIN)/test_parse $(BIN)/test_check \
$(BIN)/test_convwrap_audit \
$(BIN)/test_slice_of_slice_index \
$(BIN)/test_amp_dot_idx \
$(BIN)/test_alias_chain_unwrap \
$(BIN)/test_param_shadow_mod \
$(BIN)/test_localoff_scope \
$(BIN)/test_cast_enum_movl \
@@ -755,6 +756,12 @@ $(BIN)/test_amp_dot_idx: test/wcc/755_amp_dot_idx.c \
$(LIB)/libwwrt.a | $(BIN)
$(CC) $(CFLAGS) -o $@ $<
$(BIN)/test_alias_chain_unwrap: test/wcc/756_alias_chain_unwrap.c \
$(BIN)/ww $(BIN)/w6c $(BIN)/w6a $(BIN)/w6l \
$(BIN)/ww_ww $(BIN)/w6c_ww $(BIN)/w6a_ww $(BIN)/w6l_ww \
$(LIB)/libwwrt.a | $(BIN)
$(CC) $(CFLAGS) -o $@ $<
$(BIN)/test_match_4arm_cross_module_run: test/wcc/929_match_4arm_cross_module_run.c \
$(BIN)/ww $(BIN)/w6c $(BIN)/w6a $(BIN)/w6l \
$(BIN)/ww_ww $(BIN)/w6c_ww $(BIN)/w6a_ww $(BIN)/w6l_ww \

77
cmd/w6c/cgen.c
View File

@@ -123,6 +123,19 @@ cg_isfloat(Type *t)
|| t->kind == TY_UNTYPED_FLOAT;
}
/* type_chase_named — walk the TY_NAMED.under chain to the deepest non-
* named type. Chain-of-aliases (#22): `type b = a; type a = struct;`
* stacks two TY_NAMED layers — a single peel leaves `t` pointing at
* the inner alias (still TY_NAMED), so kind-gated arms (TY_STRUCT,
* TY_SLICE, TY_TAGGED, TY_PTR) miss and the codegen silently falls
* through to a scalar shape. Mirror of wwstage's structlookupchain. */
static Type *
type_chase_named(Type *t)
{
while (t && t->kind == TY_NAMED) t = t->under;
return t;
}
/* cg_sret_retsize — if `rt` is a plain TY_STRUCT > 24B, return its
* natural size (the sret threshold); else 0. Tagged unions, tuples,
* str, and slices route through their existing register-return ABIs
@@ -130,8 +143,7 @@ cg_isfloat(Type *t)
static int
cg_sret_retsize(Type *rt)
{
if (rt == NULL) return 0;
if (rt->kind == TY_NAMED) rt = rt->under;
rt = type_chase_named(rt);
if (rt == NULL || rt->kind != TY_STRUCT) return 0;
if ((int)rt->size <= 24) return 0;
return (int)rt->size;
@@ -2408,12 +2420,16 @@ cgexpr(Cg *c, Node *n, Local *locals)
Node *base = n->lhs->lhs;
if (base->kind == N_UN) base = base->lhs;
Type *bt = base->type;
Type *u = (bt && bt->kind == TY_NAMED) ? bt->under : bt;
/* type_chase_named (#22): a chain `type b = a; a = struct`
* left u at TY_NAMED a after a single peel, missing the
* TY_STRUCT field-walk gate below — the assignment
* silently dropped (the `break` at the bottom of the
* N_DOT-lhs arm). */
Type *u = type_chase_named(bt);
int via_ptr = 0;
if (u && u->kind == TY_PTR) {
via_ptr = 1;
u = u->sub;
if (u && u->kind == TY_NAMED) u = u->under;
u = type_chase_named(u->sub);
}
/* slice/str pseudo-field write (.ptr/.len/.cap) */
if (u && (u->kind == TY_SLICE || u->kind == TY_STR)) {
@@ -3013,10 +3029,11 @@ cgexpr(Cg *c, Node *n, Local *locals)
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;
/* type_chase_named (#22); same rationale as the cgexpr-
* side pointer-to-struct field branch. */
Type *bu = type_chase_named(bt);
if (bu && bu->kind == TY_PTR && bu->sub) {
Type *inner = bu->sub;
if (inner->kind == TY_NAMED) inner = inner->under;
Type *inner = type_chase_named(bu->sub);
if (inner && inner->kind == TY_STRUCT) {
Tfield *f = NULL;
for (Tfield *fl = inner->fields; fl; fl = fl->next)
@@ -5325,7 +5342,12 @@ cgexpr(Cg *c, Node *n, Local *locals)
&& dot_lhs->lhs && dot_lhs->lhs->kind == N_IDENT)
dot_lhs = dot_lhs->lhs;
Type *bt = dot_lhs ? dot_lhs->type : NULL;
Type *u = (bt && bt->kind == TY_NAMED) ? bt->under : bt;
/* type_chase_named (#22): `type b = a; type a = struct;` stacks
* two TY_NAMED layers; single peel left `u` still TY_NAMED,
* missing the TY_STRUCT field-walk gate below and collapsing
* `s.field` to a base-only MOVQ read (offset 0 instead of
* the field's declared offset). */
Type *u = type_chase_named(bt);
/* Module-qualified value reference: `mod.name`. The checker
* leaves SK_USE idents untyped (NULL/ty_err); detect that and
* look up the leaf in the flat (driver-concatenated) sym/def
@@ -5797,8 +5819,7 @@ cgexpr(Cg *c, Node *n, Local *locals)
* IDENT)) emits the same load as `p.len` after the case-top
* retarget. */
if (u && u->kind == TY_PTR && u->sub) {
Type *inner = u->sub;
if (inner->kind == TY_NAMED) inner = inner->under;
Type *inner = type_chase_named(u->sub);
if (inner && (inner->kind == TY_SLICE || inner->kind == TY_STR)
&& (lenfld || capfld || ptrfld)
&& dot_lhs && dot_lhs->kind == N_IDENT) {
@@ -5813,10 +5834,15 @@ cgexpr(Cg *c, Node *n, Local *locals)
* fn move(p: *point) ... { p.x += dx; ... }
* dot_lhs gates this branch so both `p.f` (n->lhs is IDENT)
* and `(*p).f` (n->lhs is N_UN(STAR, IDENT), retargeted to
* inner IDENT at case-top) emit the same load sequence. */
* inner IDENT at case-top) emit the same load sequence.
*
* type_chase_named (#22): `type b = a;` inside the pointer
* (`*b`) leaves a single peel still at TY_NAMED. Bites the
* strings.tokenize wrapper shape — caller signature
* `next_token(s: *strings.tokenizer)` where strings.tokenizer
* aliases bytes.tokenizer. */
if (u && u->kind == TY_PTR && u->sub) {
Type *inner = u->sub;
if (inner->kind == TY_NAMED) inner = inner->under;
Type *inner = type_chase_named(u->sub);
if (inner && inner->kind == TY_STRUCT
&& dot_lhs && dot_lhs->kind == N_IDENT) {
int off = localfind(locals, dot_lhs->str);
@@ -6290,7 +6316,12 @@ cgstmt(Cg *c, Node *n, Local **locals, int *frame)
break;
case N_LET: {
Type *lt = n->type;
Type *lu = (lt && lt->kind == TY_NAMED) ? lt->under : lt;
/* type_chase_named (#22): a chain `type a = struct{...};
* type b = a;` stacks two TY_NAMED layers. A single peel
* left `lu` pointing at the inner alias (still TY_NAMED),
* collapsed the struct/slice/tagged sizing arms to the 8B
* fallback, and the slot under-allocated the local. */
Type *lu = type_chase_named(lt);
int sz = 8;
if (lu && lu->kind == TY_ARRAY) sz = (int)lu->size;
else if (lu && lu->kind == TY_SLICE) sz = 24;
@@ -6829,8 +6860,14 @@ cgstmt(Cg *c, Node *n, Local **locals, int *frame)
* SysV sret discipline of "return the pointer". No
* AX/DX/CX shuffle, no scratch slot beyond @sretarg. */
if (n->lhs && cg_ret_type && cg_sret_arg_off != 0) {
Type *rt = cg_ret_type;
if (rt->kind == TY_NAMED) rt = rt->under;
/* type_chase_named (#22). A single peel left `rt` still
* TY_NAMED when the declared return type is `type b
* = a;` where a is itself a NAMED alias of a struct,
* so the TY_STRUCT gate below missed and the sret
* return arm fell through to the scalar-AX default —
* corrupting the caller's receive slot even though
* the prologue wired @sretarg. */
Type *rt = type_chase_named(cg_ret_type);
/* sret return-forwarding (task #9 follow-up to #23):
* `return f();` where outer + inner both return the
* same >24B struct shape. Outer's @sretarg already
@@ -6939,8 +6976,10 @@ cgstmt(Cg *c, Node *n, Local **locals, int *frame)
* N_STRUCTLIT (field-by-field store at scratch+foff). Call-
* result chain return is deferred to #5's receive side. */
if (n->lhs && cg_ret_type) {
Type *rt = cg_ret_type;
if (rt->kind == TY_NAMED) rt = rt->under;
/* type_chase_named (#22); see the >24B sret arm above
* for the same rationale. The ≤24B register-return
* ABI uses the same TY_STRUCT gate. */
Type *rt = type_chase_named(cg_ret_type);
if (rt && rt->kind == TY_STRUCT && rt->size <= 24
&& (n->lhs->kind == N_IDENT
|| n->lhs->kind == N_STRUCTLIT)) {

66
selfhost/cmd/w6c/main.combined.ww
View File

@@ -9150,6 +9150,39 @@ fn structnaturalsize(si: *structinfo) i32 = {
// cg_sret_retsize predicate. Resolves N_TNAME → struct via structlookup
// and unwraps one leading N_TBANG so `type box = !big;` still
// triggers sret on the underlying big.
//
// Chain-of-aliases (#22): `type a = struct{...}; type b = a;` registers
// `b → a` in c.aliases (target node = N_TNAME "a"), not `b → struct`.
// When structlookup(c, "b") misses, fall through to aliaslookup and
// recurse on the alias target — mirrors slotsize's N_TNAME arm
// (cgenutil.ww:1955) and the cstage while-loop in cg_sret_retsize.
// structlookupchain — resolve TNAME `tn` to its registered struct,
// chasing alias-of-alias (#22). Returns nil if the chain doesn't
// bottom out at a struct. Mirrors cstage's transitive
// `while (t->kind == TY_NAMED) t = t->under` peel; consumed by
// cgdot / cgassign at every "field-walk on a struct-typed local"
// site so a transitively-aliased struct name resolves to its
// fieldinfo list regardless of chain depth.
export fn structlookupchain(c: *cgen, tn: *node) *structinfo = {
if (tn == nil) { return nil; };
if (tn.kind != nkind.N_TNAME) { return nil; };
let si: *structinfo = structlookup(c, tn.str);
if (si != nil) { return si; };
let cur: *node = tn;
for (cur != nil && cur.kind == nkind.N_TNAME && si == nil) {
let aliased: *node = aliaslookup(c, cur.str);
if (aliased == nil) { cur = nil; }
else {
if (aliased.kind == nkind.N_TNAME) {
si = structlookup(c, aliased.str);
cur = aliased;
} else { cur = nil; };
};
};
return si;
};
export fn sretretsize(c: *cgen, t: *node) i32 = {
if (t == nil) { return 0; };
let r: *node = t;
@@ -9162,7 +9195,15 @@ export fn sretretsize(c: *cgen, t: *node) i32 = {
if (primsize(r.str) > 0) { return 0; };
if (streq(r.str, "str")) { return 0; };
let si: *structinfo = structlookup(c, r.str);
if (si == nil) { return 0; };
if (si == nil) {
if (c != nil) {
let aliased: *node = aliaslookup(c, r.str);
if (aliased != nil) {
return sretretsize(c, aliased);
};
};
return 0;
};
let n: i32 = structnaturalsize(si);
if (n <= 24) { return 0; };
return n;
@@ -12807,7 +12848,11 @@ fn cgdot(c: *cgen, n: *node) void = {
};
};
if (sname.len > 0) {
let si: *structinfo = structlookup(c, sname);
// structlookupchain walks the alias chain on
// a miss so `*tokenizer` where tokenizer is
// a transitively-aliased struct still
// resolves to the underlying fieldinfo (#22).
let si: *structinfo = structlookupchain(c, inner);
if (si != nil) {
let fi: *fieldinfo = si.fields;
for (fi != nil) {
@@ -12890,8 +12935,11 @@ fn cgdot(c: *cgen, n: *node) void = {
};
// Direct struct local: field load at off+foff.
if (lkind == nkind.N_TNAME) {
let sname: str = tn.str;
let si: *structinfo = structlookup(c, sname);
// structlookupchain walks the alias chain on
// miss so a transitively-aliased struct (`type
// b = a; a = struct`) still resolves to the
// underlying fieldinfo (#22).
let si: *structinfo = structlookupchain(c, tn);
if (si != nil) {
let fi: *fieldinfo = si.fields;
for (fi != nil) {
@@ -15556,7 +15604,10 @@ fn cgassign(c: *cgen, n: *node) void = {
if (inner.kind == nkind.N_TNAME) { sname = inner.str; };
};
if (sname.len > 0) {
let si: *structinfo = structlookup(c, sname);
// structlookupchain (#22) handles the
// alias-chain miss; same shape as the
// cgdot pointer-to-struct read site.
let si: *structinfo = structlookupchain(c, inner);
if (si != nil) {
let fi: *fieldinfo = si.fields;
for (fi != nil) {
@@ -15794,8 +15845,9 @@ fn cgassign(c: *cgen, n: *node) void = {
};
// Direct struct local: store at off+foff.
if (lkind == nkind.N_TNAME) {
let sname: str = tn.str;
let si: *structinfo = structlookup(c, sname);
// structlookupchain (#22) — same shape
// as the cgdot direct-local read site.
let si: *structinfo = structlookupchain(c, tn);
if (si != nil) {
let fi: *fieldinfo = si.fields;
for (fi != nil) {

23
selfhost/cmd/wcc/cgenexpr.ww
View File

@@ -1280,7 +1280,11 @@ fn cgdot(c: *cgen, n: *node) void = {
};
};
if (sname.len > 0) {
let si: *structinfo = structlookup(c, sname);
// structlookupchain walks the alias chain on
// a miss so `*tokenizer` where tokenizer is
// a transitively-aliased struct still
// resolves to the underlying fieldinfo (#22).
let si: *structinfo = structlookupchain(c, inner);
if (si != nil) {
let fi: *fieldinfo = si.fields;
for (fi != nil) {
@@ -1363,8 +1367,11 @@ fn cgdot(c: *cgen, n: *node) void = {
};
// Direct struct local: field load at off+foff.
if (lkind == nkind.N_TNAME) {
let sname: str = tn.str;
let si: *structinfo = structlookup(c, sname);
// structlookupchain walks the alias chain on
// miss so a transitively-aliased struct (`type
// b = a; a = struct`) still resolves to the
// underlying fieldinfo (#22).
let si: *structinfo = structlookupchain(c, tn);
if (si != nil) {
let fi: *fieldinfo = si.fields;
for (fi != nil) {
@@ -4029,7 +4036,10 @@ fn cgassign(c: *cgen, n: *node) void = {
if (inner.kind == nkind.N_TNAME) { sname = inner.str; };
};
if (sname.len > 0) {
let si: *structinfo = structlookup(c, sname);
// structlookupchain (#22) handles the
// alias-chain miss; same shape as the
// cgdot pointer-to-struct read site.
let si: *structinfo = structlookupchain(c, inner);
if (si != nil) {
let fi: *fieldinfo = si.fields;
for (fi != nil) {
@@ -4267,8 +4277,9 @@ fn cgassign(c: *cgen, n: *node) void = {
};
// Direct struct local: store at off+foff.
if (lkind == nkind.N_TNAME) {
let sname: str = tn.str;
let si: *structinfo = structlookup(c, sname);
// structlookupchain (#22) — same shape
// as the cgdot direct-local read site.
let si: *structinfo = structlookupchain(c, tn);
if (si != nil) {
let fi: *fieldinfo = si.fields;
for (fi != nil) {

43
selfhost/cmd/wcc/cgenutil.ww
View File

@@ -1520,6 +1520,39 @@ fn structnaturalsize(si: *structinfo) i32 = {
// cg_sret_retsize predicate. Resolves N_TNAME → struct via structlookup
// and unwraps one leading N_TBANG so `type box = !big;` still
// triggers sret on the underlying big.
//
// Chain-of-aliases (#22): `type a = struct{...}; type b = a;` registers
// `b → a` in c.aliases (target node = N_TNAME "a"), not `b → struct`.
// When structlookup(c, "b") misses, fall through to aliaslookup and
// recurse on the alias target — mirrors slotsize's N_TNAME arm
// (cgenutil.ww:1955) and the cstage while-loop in cg_sret_retsize.
// structlookupchain — resolve TNAME `tn` to its registered struct,
// chasing alias-of-alias (#22). Returns nil if the chain doesn't
// bottom out at a struct. Mirrors cstage's transitive
// `while (t->kind == TY_NAMED) t = t->under` peel; consumed by
// cgdot / cgassign at every "field-walk on a struct-typed local"
// site so a transitively-aliased struct name resolves to its
// fieldinfo list regardless of chain depth.
export fn structlookupchain(c: *cgen, tn: *node) *structinfo = {
if (tn == nil) { return nil; };
if (tn.kind != nkind.N_TNAME) { return nil; };
let si: *structinfo = structlookup(c, tn.str);
if (si != nil) { return si; };
let cur: *node = tn;
for (cur != nil && cur.kind == nkind.N_TNAME && si == nil) {
let aliased: *node = aliaslookup(c, cur.str);
if (aliased == nil) { cur = nil; }
else {
if (aliased.kind == nkind.N_TNAME) {
si = structlookup(c, aliased.str);
cur = aliased;
} else { cur = nil; };
};
};
return si;
};
export fn sretretsize(c: *cgen, t: *node) i32 = {
if (t == nil) { return 0; };
let r: *node = t;
@@ -1532,7 +1565,15 @@ export fn sretretsize(c: *cgen, t: *node) i32 = {
if (primsize(r.str) > 0) { return 0; };
if (streq(r.str, "str")) { return 0; };
let si: *structinfo = structlookup(c, r.str);
if (si == nil) { return 0; };
if (si == nil) {
if (c != nil) {
let aliased: *node = aliaslookup(c, r.str);
if (aliased != nil) {
return sretretsize(c, aliased);
};
};
return 0;
};
let n: i32 = structnaturalsize(si);
if (n <= 24) { return 0; };
return n;

66
selfhost/cmd/wwdump/main.combined.ww
View File

@@ -9150,6 +9150,39 @@ fn structnaturalsize(si: *structinfo) i32 = {
// cg_sret_retsize predicate. Resolves N_TNAME → struct via structlookup
// and unwraps one leading N_TBANG so `type box = !big;` still
// triggers sret on the underlying big.
//
// Chain-of-aliases (#22): `type a = struct{...}; type b = a;` registers
// `b → a` in c.aliases (target node = N_TNAME "a"), not `b → struct`.
// When structlookup(c, "b") misses, fall through to aliaslookup and
// recurse on the alias target — mirrors slotsize's N_TNAME arm
// (cgenutil.ww:1955) and the cstage while-loop in cg_sret_retsize.
// structlookupchain — resolve TNAME `tn` to its registered struct,
// chasing alias-of-alias (#22). Returns nil if the chain doesn't
// bottom out at a struct. Mirrors cstage's transitive
// `while (t->kind == TY_NAMED) t = t->under` peel; consumed by
// cgdot / cgassign at every "field-walk on a struct-typed local"
// site so a transitively-aliased struct name resolves to its
// fieldinfo list regardless of chain depth.
export fn structlookupchain(c: *cgen, tn: *node) *structinfo = {
if (tn == nil) { return nil; };
if (tn.kind != nkind.N_TNAME) { return nil; };
let si: *structinfo = structlookup(c, tn.str);
if (si != nil) { return si; };
let cur: *node = tn;
for (cur != nil && cur.kind == nkind.N_TNAME && si == nil) {
let aliased: *node = aliaslookup(c, cur.str);
if (aliased == nil) { cur = nil; }
else {
if (aliased.kind == nkind.N_TNAME) {
si = structlookup(c, aliased.str);
cur = aliased;
} else { cur = nil; };
};
};
return si;
};
export fn sretretsize(c: *cgen, t: *node) i32 = {
if (t == nil) { return 0; };
let r: *node = t;
@@ -9162,7 +9195,15 @@ export fn sretretsize(c: *cgen, t: *node) i32 = {
if (primsize(r.str) > 0) { return 0; };
if (streq(r.str, "str")) { return 0; };
let si: *structinfo = structlookup(c, r.str);
if (si == nil) { return 0; };
if (si == nil) {
if (c != nil) {
let aliased: *node = aliaslookup(c, r.str);
if (aliased != nil) {
return sretretsize(c, aliased);
};
};
return 0;
};
let n: i32 = structnaturalsize(si);
if (n <= 24) { return 0; };
return n;
@@ -12807,7 +12848,11 @@ fn cgdot(c: *cgen, n: *node) void = {
};
};
if (sname.len > 0) {
let si: *structinfo = structlookup(c, sname);
// structlookupchain walks the alias chain on
// a miss so `*tokenizer` where tokenizer is
// a transitively-aliased struct still
// resolves to the underlying fieldinfo (#22).
let si: *structinfo = structlookupchain(c, inner);
if (si != nil) {
let fi: *fieldinfo = si.fields;
for (fi != nil) {
@@ -12890,8 +12935,11 @@ fn cgdot(c: *cgen, n: *node) void = {
};
// Direct struct local: field load at off+foff.
if (lkind == nkind.N_TNAME) {
let sname: str = tn.str;
let si: *structinfo = structlookup(c, sname);
// structlookupchain walks the alias chain on
// miss so a transitively-aliased struct (`type
// b = a; a = struct`) still resolves to the
// underlying fieldinfo (#22).
let si: *structinfo = structlookupchain(c, tn);
if (si != nil) {
let fi: *fieldinfo = si.fields;
for (fi != nil) {
@@ -15556,7 +15604,10 @@ fn cgassign(c: *cgen, n: *node) void = {
if (inner.kind == nkind.N_TNAME) { sname = inner.str; };
};
if (sname.len > 0) {
let si: *structinfo = structlookup(c, sname);
// structlookupchain (#22) handles the
// alias-chain miss; same shape as the
// cgdot pointer-to-struct read site.
let si: *structinfo = structlookupchain(c, inner);
if (si != nil) {
let fi: *fieldinfo = si.fields;
for (fi != nil) {
@@ -15794,8 +15845,9 @@ fn cgassign(c: *cgen, n: *node) void = {
};
// Direct struct local: store at off+foff.
if (lkind == nkind.N_TNAME) {
let sname: str = tn.str;
let si: *structinfo = structlookup(c, sname);
// structlookupchain (#22) — same shape
// as the cgdot direct-local read site.
let si: *structinfo = structlookupchain(c, tn);
if (si != nil) {
let fi: *fieldinfo = si.fields;
for (fi != nil) {

271
test/wcc/756_alias_chain_unwrap.c Normal file
View File

@@ -0,0 +1,271 @@
/*
* 756_alias_chain_unwrap — sentinel for #22 alias-chain SRET/N_DOT
* wedge. Pre-fix both stages single-peeled `if (t->kind == TY_NAMED)
* t = t->under` in cg_sret_retsize / N_LET sizing / cgreturn / N_DOT
* field-access (cstage) and structlookup-on-N_TNAME (wwstage); a
* `type b = a;` over an alias-of-struct stacked two TY_NAMED layers
* and the single peel bottomed out at the inner alias — still
* TY_NAMED, not TY_STRUCT. Outcome: SRET-shaped returns silently
* routed through the scalar-AX ABI (caller's receive slot
* corrupted), let-init slots under-sized, and `s.field` reads
* collapsed to base+0 instead of base+field_offset.
*
* Polarity (rule 10, mutual-symmetric): cstage's hot-path peels
* graduated to a transitive `while (t->kind == TY_NAMED) t = t->under`
* walk; wwstage's structlookup-misses fall through to aliaslookup +
* recurse, mirroring slotsize's existing N_TNAME arm (cgenutil.ww
* line 1955). The strings.tokenize wrapper shape (`type tokenizer =
* bytes::tokenizer;`) is the original surfacing site (#22).
*
* row | shape | gate
* ---------------------+----------------------------------------+--------
* r1_i32_struct | direct TY_STRUCT, no alias | works pre-fix
* r2_slice_single | `type a = struct{[]u8,[]u8,i64}` | wedge pre-fix (RC=12)
* | aliased once → `type b = a;` |
* r3_slice_direct | direct struct, slice fields | works pre-fix
* r4_i32_double | `type b = a; type a = struct{i32...}` | wedge pre-fix (RC=14)
* | aliased twice → `type c = b;` |
*
* Each row asserts:
* - cstage RC == 0
* - wwstage RC == 0 (when w6c_ww present)
* - cstage and wwstage emit byte-identical asm
*
* Pre-fix: rows 2 and 4 fail the RC check on both stages and the
* byte-id is also broken on rows 2/4 (one stage emits sret discipline,
* the other emits the scalar-AX fall-through). Post-fix all 12
* fixtures pass.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/stat.h>
#include <sys/wait.h>
static int
runwait(const char *cmd)
{
int rc = system(cmd);
if (rc == -1) return -1;
if (WIFEXITED(rc)) return WEXITSTATUS(rc);
return -1;
}
struct row { const char *label; const char *src; };
static const struct row rows[] = {
/* r1: direct i32-fields struct, no alias. Baseline — single
* TY_NAMED layer (the type itself) suffices for the existing
* single-peel pattern. */
{ "r1_i32_struct",
"package main;\n"
"type r1 = struct {\n"
"\ta: i32, b: i32, c: i32, d: i32, e: i32, f: i32, g: i32,\n"
"\th: i32, i: i32, j: i32, k: i32, l: i32, m: i32, p: i32,\n"
"};\n"
"fn make_r1() r1 = {\n"
"\tlet b: r1;\n"
"\tb.p = 99i32;\n"
"\treturn b;\n"
"};\n"
"export fn main() i32 = {\n"
"\tlet s: r1 = make_r1();\n"
"\tif (s.p != 99i32) { return 11; };\n"
"\treturn 0;\n"
"};\n",
},
/* r2: slice-fields struct aliased once. Pre-fix wedge:
* `type r2_alias = r2_struct;` stacks two TY_NAMED layers, the
* single peel lands on the inner alias and the SRET gate falls
* through to scalar-AX. RC=12 pre-fix on both stages. */
{ "r2_slice_single",
"package main;\n"
"type r2_struct = struct { in: []u8, delim: []u8, p: i64 };\n"
"type r2_alias = r2_struct;\n"
"fn make_r2() r2_alias = {\n"
"\tlet b: r2_struct;\n"
"\tb.p = 99i64;\n"
"\treturn b;\n"
"};\n"
"export fn main() i32 = {\n"
"\tlet s: r2_alias = make_r2();\n"
"\tif (s.p != 99i64) { return 12; };\n"
"\treturn 0;\n"
"};\n",
},
/* r3: slice-fields struct, no alias — baseline that proves the
* slice-payload sret discipline itself is unaffected. */
{ "r3_slice_direct",
"package main;\n"
"type r3 = struct { in: []u8, delim: []u8, p: i64 };\n"
"fn make_r3() r3 = {\n"
"\tlet b: r3;\n"
"\tb.p = 99i64;\n"
"\treturn b;\n"
"};\n"
"export fn main() i32 = {\n"
"\tlet s: r3 = make_r3();\n"
"\tif (s.p != 99i64) { return 13; };\n"
"\treturn 0;\n"
"};\n",
},
/* r4: i32-fields struct double-aliased. Same wedge as r2 but
* chain length 3 — extra TY_NAMED layer between the alias and
* the struct. Confirms the discriminator is the chain length,
* not the field shape. RC=14 pre-fix on both stages. */
{ "r4_i32_double",
"package main;\n"
"type r4_struct = struct {\n"
"\ta: i32, b: i32, c: i32, d: i32, e: i32, f: i32, g: i32,\n"
"\th: i32, i: i32, j: i32, k: i32, l: i32, m: i32, p: i32,\n"
"};\n"
"type r4_base = r4_struct;\n"
"type r4_alias = r4_base;\n"
"fn make_r4() r4_alias = {\n"
"\tlet b: r4_alias;\n"
"\tb.p = 99i32;\n"
"\treturn b;\n"
"};\n"
"export fn main() i32 = {\n"
"\tlet s: r4_alias = make_r4();\n"
"\tif (s.p != 99i32) { return 14; };\n"
"\treturn 0;\n"
"};\n",
},
};
static int
build_and_run(const char *driver, const struct row *r, int i)
{
char src[64], tmpdir[64], cmd[1024];
snprintf(src, sizeof src, "/tmp/acu_%d_%d.ww", getpid(), i);
snprintf(tmpdir, sizeof tmpdir, "/tmp/acu_%d_d_%d", getpid(), i);
FILE *f = fopen(src, "wb");
if (!f) return -1;
fputs(r->src, f);
fclose(f);
mkdir(tmpdir, 0755);
snprintf(cmd, sizeof cmd, "cd %s && %s build %s",
tmpdir, driver, src);
if (runwait(cmd) != 0) {
fprintf(stderr, "row[%s]: build via %s failed\n",
r->label, driver);
unlink(src); rmdir(tmpdir);
return -1;
}
const char *base = strrchr(src, '/');
base = base ? base + 1 : src;
char outbin[128];
snprintf(outbin, sizeof outbin, "%s/%s", tmpdir, base);
char *dot = strrchr(outbin, '.');
if (dot && strcmp(dot, ".ww") == 0) *dot = '\0';
int got = runwait(outbin);
unlink(src); unlink(outbin); rmdir(tmpdir);
return got;
}
static int
emit_s(const char *w6c, const struct row *r, int i, char *out_s, size_t cap)
{
char src[96], cmd[1024];
snprintf(src, sizeof src, "/tmp/acu_s_%d_%d.ww", getpid(), i);
snprintf(out_s, cap, "/tmp/acu_s_%d_%d_%s.s",
getpid(), i, w6c[strlen(w6c) - 1] == 'w' ? "ww" : "c");
FILE *f = fopen(src, "wb");
if (!f) return -1;
fputs(r->src, f);
fclose(f);
snprintf(cmd, sizeof cmd, "%s -o %s %s 2>/dev/null", w6c, out_s, src);
int rc = runwait(cmd);
unlink(src);
return rc;
}
int
main(void)
{
const char *bin = getenv("BIN");
if (!bin) bin = "out/bin";
char absbin[512];
if (bin[0] != '/') {
char cwd[256];
if (getcwd(cwd, sizeof cwd) == NULL) return 1;
snprintf(absbin, sizeof absbin, "%s/%s", cwd, bin);
bin = absbin;
}
char cdrv[640], wdrv[640];
snprintf(cdrv, sizeof cdrv, "%s/ww", bin);
snprintf(wdrv, sizeof wdrv, "%s/ww_ww", bin);
char cw6c[640], ww6c[640];
snprintf(cw6c, sizeof cw6c, "%s/w6c", bin);
snprintf(ww6c, sizeof ww6c, "%s/w6c_ww", bin);
int have_ww = (access(wdrv, X_OK) == 0)
&& (access(ww6c, X_OK) == 0);
int n = (int)(sizeof rows / sizeof rows[0]);
int total = 0, fail = 0;
for (int i = 0; i < n; i++) {
/* cstage RC */
total++;
int got_c = build_and_run(cdrv, &rows[i], i);
if (got_c != 0) {
fprintf(stderr,
"alias_chain[cstage][%s]: exit=%d want=0\n",
rows[i].label, got_c);
fail++;
}
if (!have_ww) continue;
/* wwstage RC */
total++;
int got_w = build_and_run(wdrv, &rows[i], i);
if (got_w != 0) {
fprintf(stderr,
"alias_chain[wwstage][%s]: exit=%d want=0\n",
rows[i].label, got_w);
fail++;
}
/* byte-id cstage vs wwstage */
total++;
char cs_path[160], ws_path[160];
if (emit_s(cw6c, &rows[i], i, cs_path, sizeof cs_path) != 0
|| emit_s(ww6c, &rows[i], i, ws_path, sizeof ws_path) != 0) {
fprintf(stderr,
"alias_chain[byte-id][%s]: emit failed\n",
rows[i].label);
fail++;
unlink(cs_path); unlink(ws_path);
continue;
}
char cmpcmd[512];
snprintf(cmpcmd, sizeof cmpcmd, "cmp -s %s %s",
cs_path, ws_path);
if (runwait(cmpcmd) != 0) {
fprintf(stderr,
"alias_chain[byte-id][%s]: cstage vs wwstage asm differs\n",
rows[i].label);
fail++;
}
unlink(cs_path); unlink(ws_path);
}
if (fail) {
fprintf(stderr,
"alias_chain: %d/%d fixtures failed\n", fail, total);
return 1;
}
printf("alias_chain: %d/%d ok\n", total, total);
return 0;
}