wcc/check: #14 nominal typeeqast (aliassym) closes A6 cross-module variant identity (wwstage)

typeeqast's N_TNAME arm compared variant types by SURFACE string
(streq(aa.str, bb.str)), so a cross-module type referenced bare
(oserror) vs qualified (os.oserror) mis-compared unequal -> A6:
concrete->tagged silently mis-identified the variant. Resolve each
name to its canonical type sym before comparing: keep the streq
fast-path, else aliassym(c,aa)==aliassym(c,bb) (ww's existing resolver
maps bare [#53] and qualified [#51] to the same SK_TYPE sym). AST
analog of cstage type.c:278 TY_NAMED a==b / harec types.c:579
ident_equal -- NO interning. `c` threaded into 21 typeeqast sites.
B-full Layer 1: closes A6/#14; Layer 2 (A7 tagged->tagged subset
reject) stays deferred to the #199b flatten arc. Byte-id-neutral;
graduates shlex #59.15 (989 M_WWREJECT->M_ID). test/wcc/839 pins
both-stage symmetry (discriminating teeth = 989 #59.15, per 839 doc).

Makefile

@@ -263,6 +263,7 @@ TESTS	= $(BIN)/test_smoke $(BIN)/test_lex $(BIN)/test_parse $(BIN)/test_check \
 	  $(BIN)/test_tagged_assignable_cluster \
 	  $(BIN)/test_idcast_tagged_return \
 	  $(BIN)/test_global_tagged_castinit \
+	  $(BIN)/test_xmod_nominal_typeeqast \
 	  $(BIN)/test_inferred_array_global \
 	  $(BIN)/test_slice_str_global_arg \
 	  $(BIN)/test_slice_str_global_zero \
@@ -758,6 +759,12 @@ $(BIN)/test_global_tagged_castinit: test/wcc/838_global_tagged_castinit.c $(BIN)
 		$(LIB)/libwwrt.a | $(BIN)
 	$(CC) $(CFLAGS) -o $@ $<
 
+$(BIN)/test_xmod_nominal_typeeqast: test/wcc/839_xmod_nominal_typeeqast.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_inferred_array_global: test/wcc/833_inferred_array_global.c $(BIN)/ww \
 		$(BIN)/w6c $(BIN)/w6a $(BIN)/w6l \
 		$(BIN)/ww_ww $(BIN)/w6c_ww $(BIN)/w6a_ww $(BIN)/w6l_ww \

selfhost/cmd/w6c/main.combined.ww

@@ -11121,23 +11121,33 @@ fn resolvealias(c: *checker, n: *node) *node = {
 
 // 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
+// types compare by string fast-path, else by resolved-decl identity
-// identity at the AST level); other nodes recurse by kind.
+// (the AST analog of cstage type.c:278 `TY_NAMED: a == b` and harec
-fn typeeqast(a: *node, b: *node) bool = {
+// types.c:579 `STORAGE_ALIAS: ident_equal`). #14 B-full Layer 1:
+// bare `oserror` vs qualified `os.oserror` resolve to the SAME
+// SK_TYPE sym (aliassym maps both via #51/#53), so a cross-module
+// nominal forward compares equal where the surface streq said false.
+fn typeeqast(c: *checker, 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_TNAME) {
-	if (k == nkind.N_TPTR)  { return typeeqast(aa.lhs, bb.lhs); };
+		if (streq(aa.str, bb.str)) { return true; };
-	if (k == nkind.N_TSLICE){ return typeeqast(aa.lhs, bb.lhs); };
+		let sa: *sym = aliassym(c, aa);
-	if (k == nkind.N_TCHAN) { return typeeqast(aa.lhs, bb.lhs); };
+		let sb: *sym = aliassym(c, bb);
+		if (sa != nil && sa == sb) { return true; };
+		return false;
+	};
+	if (k == nkind.N_TPTR)  { return typeeqast(c, aa.lhs, bb.lhs); };
+	if (k == nkind.N_TSLICE){ return typeeqast(c, aa.lhs, bb.lhs); };
+	if (k == nkind.N_TCHAN) { return typeeqast(c, 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; };
+		if (!typeeqast(c, aa.lhs, bb.lhs)) { return false; };
 		let pa: *node = aa.list;
 		let pb: *node = bb.list;
 		for (pa != nil) {
@@ -11149,7 +11159,7 @@ fn typeeqast(a: *node, b: *node) bool = {
 				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; };
+				if (!typeeqast(c, pa.lhs, pb.lhs)) { return false; };
 			};
 			pa = pa.next;
 			pb = pb.next;
@@ -11168,7 +11178,7 @@ fn typeeqast(a: *node, b: *node) bool = {
 		let pb: *node = bb.list;
 		for (pa != nil) {
 			if (pb == nil) { return false; };
-			if (!typeeqast(pa.lhs, pb.lhs)) { return false; };
+			if (!typeeqast(c, pa.lhs, pb.lhs)) { return false; };
 			pa = pa.next;
 			pb = pb.next;
 		};
@@ -11199,7 +11209,7 @@ fn typeeqast(a: *node, b: *node) bool = {
 			// lands; b1c's (void|size) has none, so byte-id is untouched.
 			if (pa.op == tkind.TK_ELLIPSIS) { return false; };
 			if (pb.op == tkind.TK_ELLIPSIS) { return false; };
-			if (!typeeqast(pa, pb)) { return false; };
+			if (!typeeqast(c, pa, pb)) { return false; };
 			pa = pa.next;
 			pb = pb.next;
 		};
@@ -12492,7 +12502,7 @@ fn unifyarith(c: *checker, ltn: *node, rtn: *node) *node = {
 	if (ru) {
 		if (isassignable(c, ltn, rtn, &conf)) { return ltn; };
 	};
-	if (typeeqast(ltn, rtn)) { return ltn; };
+	if (typeeqast(c, 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.
@@ -12568,7 +12578,7 @@ fn binoptype(c: *checker, e: *node) *node = {
 		// broad differing-types flip (typeeqast vs cstage type_eq
 		// asymmetry risk) stays out.
 		if (varianterr(c, ltn) || varianterr(c, rtn)) {
-			if (!typeeqast(ltn, rtn)) {
+			if (!typeeqast(c, ltn, rtn)) {
 				deffolderr(c, e, "operands have differing types");
 			};
 		};
@@ -13994,7 +14004,7 @@ fn addrfnptrmatches(c: *checker, ptr: *node, synth: *node) bool = {
 	let ref: *node = resolvealias(c, unwrapbang(pu.lhs));
 	if (ref == nil) { return false; };
 	if (ref.kind != nkind.N_TFN) { return false; };
-	return typeeqast(synth, ref);
+	return typeeqast(c, synth, ref);
 };
 
 // assignableaddrfn — project #206 Option C gate. Mirror of cstage
@@ -14060,7 +14070,7 @@ fn isassignable(c: *checker, dst: *node, src: *node, confident: *bool) bool = {
 	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; };
+	if (typeeqast(c, du, su)) { return true; };
 	// #258: implicit [N]T -> []T array-to-slice borrow. Hare admits an
 	// array with a defined length wherever its element slice is expected
 	// (ref/harec/src/types.c:1080-1097, the SLICE-dst arm). Element types
@@ -14070,7 +14080,7 @@ fn isassignable(c: *checker, dst: *node, src: *node, confident: *bool) bool = {
 	// explicit full slice via desugararrayslice; cgen is untouched.
 	if (du.kind == nkind.N_TSLICE) {
 		if (su.kind == nkind.N_TARRAY) {
-			if (typeeqast(du.lhs, su.lhs)) { return true; };
+			if (typeeqast(c, du.lhs, su.lhs)) { return true; };
 			return false;
 		};
 	};
@@ -14201,7 +14211,7 @@ fn isassignable(c: *checker, dst: *node, src: *node, confident: *bool) bool = {
 			let vtagged: bool = false;
 			if (vu != nil) { if (vu.kind == nkind.N_TTAGGED) { vtagged = true; }; };
 			if (vtagged && !vspread) {
-				if (typeeqast(v, src)) { return true; };
+				if (typeeqast(c, v, src)) { return true; };
 			} else {
 				let innerconf: bool = false;
 				if (isassignable(c, v, src, &innerconf)) { return true; };
@@ -14228,7 +14238,7 @@ fn isassignable(c: *checker, dst: *node, src: *node, confident: *bool) bool = {
 			let vu: *node = resolvealias(c, unwrapbang(v));
 			if (vu != nil) {
 				if (vu.kind == nkind.N_TTAGGED) {
-					if (typeeqast(v, src)) { return true; };
+					if (typeeqast(c, v, src)) { return true; };
 				};
 			};
 			v = v.next;
@@ -14375,12 +14385,12 @@ fn taggeddefmod(c: *checker, st: *node) str = {
 
 fn casecovers(c: *checker, cs: *node, want: *node, unionmod: str) bool = {
 	if (cs.lhs != nil) {
-		if (typeeqast(cs.lhs, want)) { return true; };
+		if (typeeqast(c, cs.lhs, want)) { return true; };
 		if (casevariantpairmatch(want, cs.lhs, unionmod)) { return true; };
 	};
 	let alt: *node = cs.list;
 	for (alt != nil) {
-		if (typeeqast(alt, want)) { return true; };
+		if (typeeqast(c, alt, want)) { return true; };
 		if (casevariantpairmatch(want, alt, unionmod)) { return true; };
 		alt = alt.next;
 	};
@@ -14427,7 +14437,7 @@ fn casevariantin(c: *checker, tagged: *node, pat: *node, unionmod: str) bool = {
 				};
 			};
 		};
-		if (typeeqast(v, pat)) { return true; };
+		if (typeeqast(c, v, pat)) { return true; };
 		if (casevariantpairmatch(v, pat, unionmod)) { return true; };
 		v = v.next;
 	};
@@ -14602,7 +14612,7 @@ fn taggedarrayvariantctor(c: *checker, dst: *node, src: *node) bool = {
 		let vtagged: bool = false;
 		if (vu != nil) { if (vu.kind == nkind.N_TTAGGED) { vtagged = true; }; };
 		if (vtagged && !vspread) {
-			if (typeeqast(v, src)) { return false; };
+			if (typeeqast(c, v, src)) { return false; };
 		} else {
 			let innerconf: bool = false;
 			if (isassignable(c, v, src, &innerconf)) {
@@ -14822,7 +14832,7 @@ fn desugararrayslice(c: *checker, dsttn: *node, srctn: *node, val: *node) *node
 	if (su == nil) { return val; };
 	if (du.kind != nkind.N_TSLICE) { return val; };
 	if (su.kind != nkind.N_TARRAY) { return val; };
-	if (!typeeqast(du.lhs, su.lhs)) { return val; };
+	if (!typeeqast(c, du.lhs, su.lhs)) { return val; };
 	let sl: *node = newnode(nkind.N_SLICE, val.file, val.line, val.col);
 	sl.lhs = val;	// sliced base; lo (.rhs) / hi (.cond) nil → 0 : len(arr)
 	let slt: *node = newnode(nkind.N_TSLICE, "", 0, 0);
@@ -14898,7 +14908,7 @@ fn desugarcallargs(c: *checker, n: *node) void = {
 					let au: *node = resolvealias(c, unwrapbang(atype));
 					if (pu != nil) { if (au != nil) {
 						if (pu.kind == nkind.N_TSLICE) { if (au.kind == nkind.N_TARRAY) {
-							if (!typeeqast(pu.lhs, au.lhs)) {
+							if (!typeeqast(c, pu.lhs, au.lhs)) {
 								errnotassign(c, param.lhs, atype, "argument");
 							};
 						}; };
@@ -15433,7 +15443,7 @@ fn checktryprop(c: *checker, n: *node) void = {
 			let found: bool = false;
 			let rv: *node = r.list;
 			for (rv != nil) {
-				if (typeeqast(rv, ev)) {
+				if (typeeqast(c, rv, ev)) {
 					found = true;
 					rv = nil;
 				} else { rv = rv.next; };

selfhost/cmd/wcc/check.ww

@@ -840,23 +840,33 @@ fn resolvealias(c: *checker, n: *node) *node = {
 
 // 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
+// types compare by string fast-path, else by resolved-decl identity
-// identity at the AST level); other nodes recurse by kind.
+// (the AST analog of cstage type.c:278 `TY_NAMED: a == b` and harec
-fn typeeqast(a: *node, b: *node) bool = {
+// types.c:579 `STORAGE_ALIAS: ident_equal`). #14 B-full Layer 1:
+// bare `oserror` vs qualified `os.oserror` resolve to the SAME
+// SK_TYPE sym (aliassym maps both via #51/#53), so a cross-module
+// nominal forward compares equal where the surface streq said false.
+fn typeeqast(c: *checker, 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_TNAME) {
-	if (k == nkind.N_TPTR)  { return typeeqast(aa.lhs, bb.lhs); };
+		if (streq(aa.str, bb.str)) { return true; };
-	if (k == nkind.N_TSLICE){ return typeeqast(aa.lhs, bb.lhs); };
+		let sa: *sym = aliassym(c, aa);
-	if (k == nkind.N_TCHAN) { return typeeqast(aa.lhs, bb.lhs); };
+		let sb: *sym = aliassym(c, bb);
+		if (sa != nil && sa == sb) { return true; };
+		return false;
+	};
+	if (k == nkind.N_TPTR)  { return typeeqast(c, aa.lhs, bb.lhs); };
+	if (k == nkind.N_TSLICE){ return typeeqast(c, aa.lhs, bb.lhs); };
+	if (k == nkind.N_TCHAN) { return typeeqast(c, 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; };
+		if (!typeeqast(c, aa.lhs, bb.lhs)) { return false; };
 		let pa: *node = aa.list;
 		let pb: *node = bb.list;
 		for (pa != nil) {
@@ -868,7 +878,7 @@ fn typeeqast(a: *node, b: *node) bool = {
 				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; };
+				if (!typeeqast(c, pa.lhs, pb.lhs)) { return false; };
 			};
 			pa = pa.next;
 			pb = pb.next;
@@ -887,7 +897,7 @@ fn typeeqast(a: *node, b: *node) bool = {
 		let pb: *node = bb.list;
 		for (pa != nil) {
 			if (pb == nil) { return false; };
-			if (!typeeqast(pa.lhs, pb.lhs)) { return false; };
+			if (!typeeqast(c, pa.lhs, pb.lhs)) { return false; };
 			pa = pa.next;
 			pb = pb.next;
 		};
@@ -918,7 +928,7 @@ fn typeeqast(a: *node, b: *node) bool = {
 			// lands; b1c's (void|size) has none, so byte-id is untouched.
 			if (pa.op == tkind.TK_ELLIPSIS) { return false; };
 			if (pb.op == tkind.TK_ELLIPSIS) { return false; };
-			if (!typeeqast(pa, pb)) { return false; };
+			if (!typeeqast(c, pa, pb)) { return false; };
 			pa = pa.next;
 			pb = pb.next;
 		};
@@ -2211,7 +2221,7 @@ fn unifyarith(c: *checker, ltn: *node, rtn: *node) *node = {
 	if (ru) {
 		if (isassignable(c, ltn, rtn, &conf)) { return ltn; };
 	};
-	if (typeeqast(ltn, rtn)) { return ltn; };
+	if (typeeqast(c, 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.
@@ -2287,7 +2297,7 @@ fn binoptype(c: *checker, e: *node) *node = {
 		// broad differing-types flip (typeeqast vs cstage type_eq
 		// asymmetry risk) stays out.
 		if (varianterr(c, ltn) || varianterr(c, rtn)) {
-			if (!typeeqast(ltn, rtn)) {
+			if (!typeeqast(c, ltn, rtn)) {
 				deffolderr(c, e, "operands have differing types");
 			};
 		};
@@ -3713,7 +3723,7 @@ fn addrfnptrmatches(c: *checker, ptr: *node, synth: *node) bool = {
 	let ref: *node = resolvealias(c, unwrapbang(pu.lhs));
 	if (ref == nil) { return false; };
 	if (ref.kind != nkind.N_TFN) { return false; };
-	return typeeqast(synth, ref);
+	return typeeqast(c, synth, ref);
 };
 
 // assignableaddrfn — project #206 Option C gate. Mirror of cstage
@@ -3779,7 +3789,7 @@ fn isassignable(c: *checker, dst: *node, src: *node, confident: *bool) bool = {
 	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; };
+	if (typeeqast(c, du, su)) { return true; };
 	// #258: implicit [N]T -> []T array-to-slice borrow. Hare admits an
 	// array with a defined length wherever its element slice is expected
 	// (ref/harec/src/types.c:1080-1097, the SLICE-dst arm). Element types
@@ -3789,7 +3799,7 @@ fn isassignable(c: *checker, dst: *node, src: *node, confident: *bool) bool = {
 	// explicit full slice via desugararrayslice; cgen is untouched.
 	if (du.kind == nkind.N_TSLICE) {
 		if (su.kind == nkind.N_TARRAY) {
-			if (typeeqast(du.lhs, su.lhs)) { return true; };
+			if (typeeqast(c, du.lhs, su.lhs)) { return true; };
 			return false;
 		};
 	};
@@ -3920,7 +3930,7 @@ fn isassignable(c: *checker, dst: *node, src: *node, confident: *bool) bool = {
 			let vtagged: bool = false;
 			if (vu != nil) { if (vu.kind == nkind.N_TTAGGED) { vtagged = true; }; };
 			if (vtagged && !vspread) {
-				if (typeeqast(v, src)) { return true; };
+				if (typeeqast(c, v, src)) { return true; };
 			} else {
 				let innerconf: bool = false;
 				if (isassignable(c, v, src, &innerconf)) { return true; };
@@ -3947,7 +3957,7 @@ fn isassignable(c: *checker, dst: *node, src: *node, confident: *bool) bool = {
 			let vu: *node = resolvealias(c, unwrapbang(v));
 			if (vu != nil) {
 				if (vu.kind == nkind.N_TTAGGED) {
-					if (typeeqast(v, src)) { return true; };
+					if (typeeqast(c, v, src)) { return true; };
 				};
 			};
 			v = v.next;
@@ -4094,12 +4104,12 @@ fn taggeddefmod(c: *checker, st: *node) str = {
 
 fn casecovers(c: *checker, cs: *node, want: *node, unionmod: str) bool = {
 	if (cs.lhs != nil) {
-		if (typeeqast(cs.lhs, want)) { return true; };
+		if (typeeqast(c, cs.lhs, want)) { return true; };
 		if (casevariantpairmatch(want, cs.lhs, unionmod)) { return true; };
 	};
 	let alt: *node = cs.list;
 	for (alt != nil) {
-		if (typeeqast(alt, want)) { return true; };
+		if (typeeqast(c, alt, want)) { return true; };
 		if (casevariantpairmatch(want, alt, unionmod)) { return true; };
 		alt = alt.next;
 	};
@@ -4146,7 +4156,7 @@ fn casevariantin(c: *checker, tagged: *node, pat: *node, unionmod: str) bool = {
 				};
 			};
 		};
-		if (typeeqast(v, pat)) { return true; };
+		if (typeeqast(c, v, pat)) { return true; };
 		if (casevariantpairmatch(v, pat, unionmod)) { return true; };
 		v = v.next;
 	};
@@ -4321,7 +4331,7 @@ fn taggedarrayvariantctor(c: *checker, dst: *node, src: *node) bool = {
 		let vtagged: bool = false;
 		if (vu != nil) { if (vu.kind == nkind.N_TTAGGED) { vtagged = true; }; };
 		if (vtagged && !vspread) {
-			if (typeeqast(v, src)) { return false; };
+			if (typeeqast(c, v, src)) { return false; };
 		} else {
 			let innerconf: bool = false;
 			if (isassignable(c, v, src, &innerconf)) {
@@ -4541,7 +4551,7 @@ fn desugararrayslice(c: *checker, dsttn: *node, srctn: *node, val: *node) *node
 	if (su == nil) { return val; };
 	if (du.kind != nkind.N_TSLICE) { return val; };
 	if (su.kind != nkind.N_TARRAY) { return val; };
-	if (!typeeqast(du.lhs, su.lhs)) { return val; };
+	if (!typeeqast(c, du.lhs, su.lhs)) { return val; };
 	let sl: *node = newnode(nkind.N_SLICE, val.file, val.line, val.col);
 	sl.lhs = val;	// sliced base; lo (.rhs) / hi (.cond) nil → 0 : len(arr)
 	let slt: *node = newnode(nkind.N_TSLICE, "", 0, 0);
@@ -4617,7 +4627,7 @@ fn desugarcallargs(c: *checker, n: *node) void = {
 					let au: *node = resolvealias(c, unwrapbang(atype));
 					if (pu != nil) { if (au != nil) {
 						if (pu.kind == nkind.N_TSLICE) { if (au.kind == nkind.N_TARRAY) {
-							if (!typeeqast(pu.lhs, au.lhs)) {
+							if (!typeeqast(c, pu.lhs, au.lhs)) {
 								errnotassign(c, param.lhs, atype, "argument");
 							};
 						}; };
@@ -5152,7 +5162,7 @@ fn checktryprop(c: *checker, n: *node) void = {
 			let found: bool = false;
 			let rv: *node = r.list;
 			for (rv != nil) {
-				if (typeeqast(rv, ev)) {
+				if (typeeqast(c, rv, ev)) {
 					found = true;
 					rv = nil;
 				} else { rv = rv.next; };

selfhost/cmd/wwdump/main.combined.ww

@@ -11121,23 +11121,33 @@ fn resolvealias(c: *checker, n: *node) *node = {
 
 // 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
+// types compare by string fast-path, else by resolved-decl identity
-// identity at the AST level); other nodes recurse by kind.
+// (the AST analog of cstage type.c:278 `TY_NAMED: a == b` and harec
-fn typeeqast(a: *node, b: *node) bool = {
+// types.c:579 `STORAGE_ALIAS: ident_equal`). #14 B-full Layer 1:
+// bare `oserror` vs qualified `os.oserror` resolve to the SAME
+// SK_TYPE sym (aliassym maps both via #51/#53), so a cross-module
+// nominal forward compares equal where the surface streq said false.
+fn typeeqast(c: *checker, 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_TNAME) {
-	if (k == nkind.N_TPTR)  { return typeeqast(aa.lhs, bb.lhs); };
+		if (streq(aa.str, bb.str)) { return true; };
-	if (k == nkind.N_TSLICE){ return typeeqast(aa.lhs, bb.lhs); };
+		let sa: *sym = aliassym(c, aa);
-	if (k == nkind.N_TCHAN) { return typeeqast(aa.lhs, bb.lhs); };
+		let sb: *sym = aliassym(c, bb);
+		if (sa != nil && sa == sb) { return true; };
+		return false;
+	};
+	if (k == nkind.N_TPTR)  { return typeeqast(c, aa.lhs, bb.lhs); };
+	if (k == nkind.N_TSLICE){ return typeeqast(c, aa.lhs, bb.lhs); };
+	if (k == nkind.N_TCHAN) { return typeeqast(c, 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; };
+		if (!typeeqast(c, aa.lhs, bb.lhs)) { return false; };
 		let pa: *node = aa.list;
 		let pb: *node = bb.list;
 		for (pa != nil) {
@@ -11149,7 +11159,7 @@ fn typeeqast(a: *node, b: *node) bool = {
 				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; };
+				if (!typeeqast(c, pa.lhs, pb.lhs)) { return false; };
 			};
 			pa = pa.next;
 			pb = pb.next;
@@ -11168,7 +11178,7 @@ fn typeeqast(a: *node, b: *node) bool = {
 		let pb: *node = bb.list;
 		for (pa != nil) {
 			if (pb == nil) { return false; };
-			if (!typeeqast(pa.lhs, pb.lhs)) { return false; };
+			if (!typeeqast(c, pa.lhs, pb.lhs)) { return false; };
 			pa = pa.next;
 			pb = pb.next;
 		};
@@ -11199,7 +11209,7 @@ fn typeeqast(a: *node, b: *node) bool = {
 			// lands; b1c's (void|size) has none, so byte-id is untouched.
 			if (pa.op == tkind.TK_ELLIPSIS) { return false; };
 			if (pb.op == tkind.TK_ELLIPSIS) { return false; };
-			if (!typeeqast(pa, pb)) { return false; };
+			if (!typeeqast(c, pa, pb)) { return false; };
 			pa = pa.next;
 			pb = pb.next;
 		};
@@ -12492,7 +12502,7 @@ fn unifyarith(c: *checker, ltn: *node, rtn: *node) *node = {
 	if (ru) {
 		if (isassignable(c, ltn, rtn, &conf)) { return ltn; };
 	};
-	if (typeeqast(ltn, rtn)) { return ltn; };
+	if (typeeqast(c, 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.
@@ -12568,7 +12578,7 @@ fn binoptype(c: *checker, e: *node) *node = {
 		// broad differing-types flip (typeeqast vs cstage type_eq
 		// asymmetry risk) stays out.
 		if (varianterr(c, ltn) || varianterr(c, rtn)) {
-			if (!typeeqast(ltn, rtn)) {
+			if (!typeeqast(c, ltn, rtn)) {
 				deffolderr(c, e, "operands have differing types");
 			};
 		};
@@ -13994,7 +14004,7 @@ fn addrfnptrmatches(c: *checker, ptr: *node, synth: *node) bool = {
 	let ref: *node = resolvealias(c, unwrapbang(pu.lhs));
 	if (ref == nil) { return false; };
 	if (ref.kind != nkind.N_TFN) { return false; };
-	return typeeqast(synth, ref);
+	return typeeqast(c, synth, ref);
 };
 
 // assignableaddrfn — project #206 Option C gate. Mirror of cstage
@@ -14060,7 +14070,7 @@ fn isassignable(c: *checker, dst: *node, src: *node, confident: *bool) bool = {
 	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; };
+	if (typeeqast(c, du, su)) { return true; };
 	// #258: implicit [N]T -> []T array-to-slice borrow. Hare admits an
 	// array with a defined length wherever its element slice is expected
 	// (ref/harec/src/types.c:1080-1097, the SLICE-dst arm). Element types
@@ -14070,7 +14080,7 @@ fn isassignable(c: *checker, dst: *node, src: *node, confident: *bool) bool = {
 	// explicit full slice via desugararrayslice; cgen is untouched.
 	if (du.kind == nkind.N_TSLICE) {
 		if (su.kind == nkind.N_TARRAY) {
-			if (typeeqast(du.lhs, su.lhs)) { return true; };
+			if (typeeqast(c, du.lhs, su.lhs)) { return true; };
 			return false;
 		};
 	};
@@ -14201,7 +14211,7 @@ fn isassignable(c: *checker, dst: *node, src: *node, confident: *bool) bool = {
 			let vtagged: bool = false;
 			if (vu != nil) { if (vu.kind == nkind.N_TTAGGED) { vtagged = true; }; };
 			if (vtagged && !vspread) {
-				if (typeeqast(v, src)) { return true; };
+				if (typeeqast(c, v, src)) { return true; };
 			} else {
 				let innerconf: bool = false;
 				if (isassignable(c, v, src, &innerconf)) { return true; };
@@ -14228,7 +14238,7 @@ fn isassignable(c: *checker, dst: *node, src: *node, confident: *bool) bool = {
 			let vu: *node = resolvealias(c, unwrapbang(v));
 			if (vu != nil) {
 				if (vu.kind == nkind.N_TTAGGED) {
-					if (typeeqast(v, src)) { return true; };
+					if (typeeqast(c, v, src)) { return true; };
 				};
 			};
 			v = v.next;
@@ -14375,12 +14385,12 @@ fn taggeddefmod(c: *checker, st: *node) str = {
 
 fn casecovers(c: *checker, cs: *node, want: *node, unionmod: str) bool = {
 	if (cs.lhs != nil) {
-		if (typeeqast(cs.lhs, want)) { return true; };
+		if (typeeqast(c, cs.lhs, want)) { return true; };
 		if (casevariantpairmatch(want, cs.lhs, unionmod)) { return true; };
 	};
 	let alt: *node = cs.list;
 	for (alt != nil) {
-		if (typeeqast(alt, want)) { return true; };
+		if (typeeqast(c, alt, want)) { return true; };
 		if (casevariantpairmatch(want, alt, unionmod)) { return true; };
 		alt = alt.next;
 	};
@@ -14427,7 +14437,7 @@ fn casevariantin(c: *checker, tagged: *node, pat: *node, unionmod: str) bool = {
 				};
 			};
 		};
-		if (typeeqast(v, pat)) { return true; };
+		if (typeeqast(c, v, pat)) { return true; };
 		if (casevariantpairmatch(v, pat, unionmod)) { return true; };
 		v = v.next;
 	};
@@ -14602,7 +14612,7 @@ fn taggedarrayvariantctor(c: *checker, dst: *node, src: *node) bool = {
 		let vtagged: bool = false;
 		if (vu != nil) { if (vu.kind == nkind.N_TTAGGED) { vtagged = true; }; };
 		if (vtagged && !vspread) {
-			if (typeeqast(v, src)) { return false; };
+			if (typeeqast(c, v, src)) { return false; };
 		} else {
 			let innerconf: bool = false;
 			if (isassignable(c, v, src, &innerconf)) {
@@ -14822,7 +14832,7 @@ fn desugararrayslice(c: *checker, dsttn: *node, srctn: *node, val: *node) *node
 	if (su == nil) { return val; };
 	if (du.kind != nkind.N_TSLICE) { return val; };
 	if (su.kind != nkind.N_TARRAY) { return val; };
-	if (!typeeqast(du.lhs, su.lhs)) { return val; };
+	if (!typeeqast(c, du.lhs, su.lhs)) { return val; };
 	let sl: *node = newnode(nkind.N_SLICE, val.file, val.line, val.col);
 	sl.lhs = val;	// sliced base; lo (.rhs) / hi (.cond) nil → 0 : len(arr)
 	let slt: *node = newnode(nkind.N_TSLICE, "", 0, 0);
@@ -14898,7 +14908,7 @@ fn desugarcallargs(c: *checker, n: *node) void = {
 					let au: *node = resolvealias(c, unwrapbang(atype));
 					if (pu != nil) { if (au != nil) {
 						if (pu.kind == nkind.N_TSLICE) { if (au.kind == nkind.N_TARRAY) {
-							if (!typeeqast(pu.lhs, au.lhs)) {
+							if (!typeeqast(c, pu.lhs, au.lhs)) {
 								errnotassign(c, param.lhs, atype, "argument");
 							};
 						}; };
@@ -15433,7 +15443,7 @@ fn checktryprop(c: *checker, n: *node) void = {
 			let found: bool = false;
 			let rv: *node = r.list;
 			for (rv != nil) {
-				if (typeeqast(rv, ev)) {
+				if (typeeqast(c, rv, ev)) {
 					found = true;
 					rv = nil;
 				} else { rv = rv.next; };

test/wcc/839_xmod_nominal_typeeqast.c

@@ -0,0 +1,279 @@
+/*
+ * 839_xmod_nominal_typeeqast — B-full Layer 1 (#14): typeeqast's N_TNAME
+ * arm now compares by RESOLVED-decl identity (aliassym pointer-equality),
+ * not surface spelling. A cross-module type referenced bare inside its
+ * defining module (`myerr`) and qualified by a consumer (`e.myerr`) used
+ * to mis-compare unequal (streq), so a nominal forward / variant match was
+ * silently mis-identified. cstage already equates them (type.c:278
+ * `TY_NAMED: a == b` on resolved Type); harec equates them
+ * (types.c:579 `STORAGE_ALIAS: ident_equal`). ww now matches at the AST
+ * level via the existing #51/#53 resolver — NO type-interning layer.
+ *
+ * The headline discriminator for this fix is the lib/shlex graduation
+ * (989 #59.15: M_WWREJECT -> M_ID). That flip needs shlex's full
+ * `(size | io.error)` match pipeline and is NOT reproducible standalone,
+ * so the gate that actually distinguishes pre-fix surface-streq from
+ * post-fix nominal-aliassym is 989_lib_byteid, not this test.
+ *
+ *   scenario          | shape                                       | gate
+ *   ------------------+---------------------------------------------+------
+ *   nominal_match     | match e.res whose variants are spelled BARE |  42
+ *                     |   inside e, with QUALIFIED case patterns    |
+ *                     |   (`case e.myerr`) — nominal cover          |
+ *   a6_concrete       | concrete `e.myerr` returned into `e.res`    |   0
+ *                     |   (A6 concrete->tagged, bare-vs-qualified)  |
+ *   incompat_concrete | `str` into `(i64 | e.myerr)` — NO str       | FAIL
+ *                     |   variant: confident reject (no over-accept)|
+ *   distinct_alias    | distinct alias `other = !i64` into `e.res`  | FAIL
+ *                     |   — rejected at CGEN (#95 structural        |
+ *                     |   ambiguity: two i64-underlying variants),  |
+ *                     |   symmetric both stages                     |
+ *
+ * SCOPE / no-teeth disclosure: all four rows decide IDENTICALLY against
+ * the pre-fix surface-streq HEAD (nominal_match->42, a6_concrete->0, the
+ * two NEG rows reject) on BOTH stages — the nominal-identity change does
+ * not flip any of them, because each is reached through a sibling
+ * mechanism that already handled bare-vs-qualified: nominal_match via
+ * casevariantpairmatch (#205 match-cover resolve), a6_concrete via the
+ * concrete->tagged arm's underlying-i64 resolvealias, and distinct_alias
+ * via the cgen #95 ambiguity reject (the CHECKER accepts it — `other`'s
+ * underlying i64 matches a variant; the reject is structural, not
+ * nominal). So this test does NOT guard a revert of typeeqast to streq;
+ * that is 989 #59.15's job. What it DOES pin is that the four
+ * cross-module nominal accept/reject decisions stay correct AND symmetric
+ * across cstage/wwstage (rule-10) — a forward guard against either stage
+ * drifting on cross-module nominal forwards.
+ *
+ * Both stages must agree (rule-10): the POS rows build+run to the same
+ * exit on cstage and wwstage; the NEG rows build-FAIL on both. Byte-id of
+ * the emitted asm is NOT asserted here — receiving a cross-module tagged
+ * return and re-passing it crosses a pre-existing, unrelated cgen frame-
+ * layout divergence; B-full Layer 1's byte-id-neutrality is gated by
+ * 989_lib_byteid + 990-997 (the bootstrap forwards).
+ */
+#include <stdio.h>
+#include <stdlib.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 file { const char *name; const char *src; };
+
+struct scenario {
+	const char *label;
+	const struct file *files;	/* name==NULL terminates */
+	int expect_build;		/* 1 = build+run to want_exit; 0 = must FAIL */
+	int want_exit;
+};
+
+/* ---- nominal_match: bare union variants, qualified case patterns ---- */
+static const struct file nominal_match_files[] = {
+	{ "e.ww",
+	  "package e;\n"
+	  "\n"
+	  "export type myerr = !i64;\n"
+	  "export type res = (i64 | myerr);\n"
+	  "\n"
+	  "export fn ok(v: i64) res = { return v; };\n"
+	  "export fn bad() res = { return (-7: myerr); };\n" },
+	{ "main.ww",
+	  "package main;\n"
+	  "\n"
+	  "import e;\n"
+	  "\n"
+	  "fn unwrap(r: e.res) i64 = {\n"
+	  "	match (r) {\n"
+	  "	case let n: i64 => return n;\n"
+	  "	case let x: e.myerr => return -1;\n"
+	  "	};\n"
+	  "};\n"
+	  "\n"
+	  "export fn main() i32 = {\n"
+	  "	let a = unwrap(e.ok(40));\n"
+	  "	let b = unwrap(e.bad());\n"
+	  "	if (a != 40) { return 11; };\n"
+	  "	if (b != -1) { return 12; };\n"
+	  "	return 42;\n"
+	  "};\n" },
+	{ NULL, NULL }
+};
+
+/* ---- a6_concrete: concrete e.myerr into e.res return (A6) ---------- */
+static const struct file a6_concrete_files[] = {
+	{ "e.ww",
+	  "package e;\n"
+	  "\n"
+	  "export type myerr = !i64;\n"
+	  "export type res = (i64 | myerr);\n" },
+	{ "main.ww",
+	  "package main;\n"
+	  "\n"
+	  "import e;\n"
+	  "\n"
+	  "fn wrap(x: e.myerr) e.res = { return x; };\n"
+	  "\n"
+	  "export fn main() i32 = { return 0; };\n" },
+	{ NULL, NULL }
+};
+
+/* ---- incompat_concrete: str into (i64|e.myerr) — must reject ------- */
+static const struct file incompat_concrete_files[] = {
+	{ "e.ww",
+	  "package e;\n"
+	  "\n"
+	  "export type myerr = !i64;\n" },
+	{ "main.ww",
+	  "package main;\n"
+	  "\n"
+	  "import e;\n"
+	  "\n"
+	  "type u = (i64 | e.myerr);\n"
+	  "\n"
+	  "fn bad(s: str) u = { return s; };\n"
+	  "\n"
+	  "export fn main() i32 = { return 0; };\n" },
+	{ NULL, NULL }
+};
+
+/* ---- distinct_alias: distinct alias over same underlying — reject -- */
+static const struct file distinct_alias_files[] = {
+	{ "e.ww",
+	  "package e;\n"
+	  "\n"
+	  "export type myerr = !i64;\n"
+	  "export type res = (i64 | myerr);\n" },
+	{ "main.ww",
+	  "package main;\n"
+	  "\n"
+	  "import e;\n"
+	  "\n"
+	  "type other = !i64;\n"
+	  "\n"
+	  "fn f(x: other) e.res = { return x; };\n"
+	  "\n"
+	  "export fn main() i32 = { return 0; };\n" },
+	{ NULL, NULL }
+};
+
+static const struct scenario scenarios[] = {
+	{ "nominal_match",     nominal_match_files,     1, 42 },
+	{ "a6_concrete",       a6_concrete_files,       1, 0 },
+	{ "incompat_concrete", incompat_concrete_files, 0, 0 },
+	{ "distinct_alias",    distinct_alias_files,    0, 0 },
+};
+
+struct driver { const char *name; char path[2100]; int gated; };
+
+static int
+run_one(const struct driver *drv, const struct scenario *sc)
+{
+	char dir[] = "/tmp/ww839_XXXXXX";
+	if (mkdtemp(dir) == NULL) {
+		fprintf(stderr, "839[%s][%s]: mkdtemp failed\n",
+		    drv->name, sc->label);
+		return -1;
+	}
+
+	char path[1024], cmd[4096];
+	int rc = 0;
+
+	for (int i = 0; sc->files[i].name; i++) {
+		snprintf(path, sizeof path, "%s/%s", dir, sc->files[i].name);
+		FILE *f = fopen(path, "wb");
+		if (!f) {
+			fprintf(stderr, "839[%s][%s]: write %s\n",
+			    drv->name, sc->label, sc->files[i].name);
+			rc = -1; goto done;
+		}
+		fputs(sc->files[i].src, f);
+		fclose(f);
+	}
+
+	snprintf(cmd, sizeof cmd, "cd %s && %s build -I %s %s/main.ww "
+	    ">/dev/null 2>&1", dir, drv->path, dir, dir);
+	int brc = runwait(cmd);
+
+	if (!sc->expect_build) {
+		/* NEG: the build must FAIL on this stage. */
+		if (brc == 0) {
+			fprintf(stderr, "839[%s][%s]: built ok, expected a "
+			    "confident reject\n", drv->name, sc->label);
+			rc = -1;
+		}
+		goto done;
+	}
+
+	if (brc != 0) {
+		fprintf(stderr, "839[%s][%s]: build failed, expected ok\n",
+		    drv->name, sc->label);
+		rc = -1; goto done;
+	}
+	snprintf(path, sizeof path, "%s/main", dir);
+	int got = runwait(path);
+	if (got != sc->want_exit) {
+		fprintf(stderr, "839[%s][%s]: exit %d, want %d\n",
+		    drv->name, sc->label, got, sc->want_exit);
+		rc = -1;
+	}
+
+done:
+	snprintf(cmd, sizeof cmd, "rm -rf %s", dir);
+	(void)runwait(cmd);
+	return rc;
+}
+
+int
+main(void)
+{
+	const char *bin = getenv("BIN");
+	if (!bin) bin = "out/bin";
+	char absbin[2048];
+	if (bin[0] != '/') {
+		char cwd[1024];
+		if (getcwd(cwd, sizeof cwd) == NULL) return 1;
+		snprintf(absbin, sizeof absbin, "%s/%s", cwd, bin);
+		bin = absbin;
+	}
+
+	struct driver drivers[2];
+	snprintf(drivers[0].path, sizeof drivers[0].path, "%s/ww", bin);
+	drivers[0].name = "cstage";
+	drivers[0].gated = 0;
+	snprintf(drivers[1].path, sizeof drivers[1].path, "%s/ww_ww", bin);
+	drivers[1].name = "wwstage";
+	drivers[1].gated = 1;
+
+	int n = (int)(sizeof scenarios / sizeof scenarios[0]);
+	int total = 0, fail = 0;
+
+	for (int d = 0; d < 2; d++) {
+		if (drivers[d].gated && access(drivers[d].path, X_OK) != 0) {
+			fprintf(stderr, "839: skip %s (no %s)\n",
+			    drivers[d].name, drivers[d].path);
+			continue;
+		}
+		for (int i = 0; i < n; i++) {
+			total++;
+			if (run_one(&drivers[d], &scenarios[i]) != 0)
+				fail++;
+		}
+	}
+
+	if (fail) {
+		fprintf(stderr, "839 xmod_nominal_typeeqast: %d/%d failed\n",
+		    fail, total);
+		return 1;
+	}
+	printf("xmod_nominal_typeeqast: %d/%d ok (cross-module nominal "
+	    "accept + reject, both stages)\n", total, total);
+	return 0;
+}

test/wcc/989_lib_byteid.c

@@ -157,8 +157,11 @@ static const struct ent ents[] = {
 	  .mode = M_WWREJECT, .cite = "#59.13" },
 	{ .fixture = "lib/fnmatch/fnmatchtest.ww",
 	  .mode = M_WWREJECT, .cite = "#59.14" },
+	/* #59.15 shlex graduated to M_ID by B-full Layer 1 (#14 nominal
+	 * typeeqast): the cross-module bare-vs-qualified variant forward
+	 * w6c_ww over-rejected now compiles byte-identically. */
 	{ .fixture = "lib/shlex/shlextest.ww",
-	  .mode = M_WWREJECT, .cite = "#59.15" },
+	  .mode = M_ID, .cite = "#59.15 graduated by #14 nominal typeeqast" },
 	{ .fixture = NULL },
 };