cgen: resolve chained-DOT fn-ptr field callees

fnptrcalleetfn's N_DOT arm required an N_IDENT base, so a.b.cb(...)
fell to the name registry with an empty module hint and emitted
CALL cb(SB) (undefined symbol; cstage calls the stamped ptr indirect).
dotbasestructinfo resolves the base chain through the struct registry
— each link a struct- or *struct-typed field — and the single-dot
path routes through the same resolver unchanged. Closes the last open
shape of the #59.8 name-keyed callee family. Fixture fnptrfield_chain;
corpus pin 1487/2974.

docs/test-system-v2.md

@@ -32,9 +32,9 @@ categories out of the ordinary developer target.
 | Fixed point and self-host | `test-bootstrap` |
 | Host linker/platform behavior | `test-platform` |
 
-The live declarative compiler corpus has 1,486 fixtures and 2,972 C/WW cells:
+The live declarative compiler corpus has 1,487 fixtures and 2,974 C/WW cells:
 338 expected rejections (314 shared and 24 stage-specific), 17 compile-only
-successes, 191 exit-zero programs, and 940 explicit-exit programs.
+successes, 191 exit-zero programs, and 941 explicit-exit programs.
 
 147 native C carriers remain. They are partitioned exactly once as five
 in-process units, 24 byte/artifact gates, six bootstrap gates, one platform

internal/wwfixture/types.ww

@@ -1,13 +1,13 @@
 package wwfixture;
 
 def protocolversion: i32 = 1;
-def corpuscount: i32 = 1486;
+def corpuscount: i32 = 1487;
 def errorcount: i32 = 338;
 def compilecount: i32 = 17;
 def runcount: i32 = 191;
-def runexitcount: i32 = 940;
-def nativecount: i32 = 2972;
-def corpushash: str = "ab4b1d1ffc078b23de0a70911740511e873cd8d6f76009c4719d704bb36e6133";
+def runexitcount: i32 = 941;
+def nativecount: i32 = 2974;
+def corpushash: str = "2520ada0b1687fab6eed6073a263c620fa4cbab6dc8156f7d51bcf8b14a9ec4a";
 
 type directive = enum i32 {
 	ERROR = 0,

selfhost/cmd/wcc/cgenutil.ww

@@ -64,6 +64,53 @@ fn findvariadicparam(ps: *syntax.node, nfixed_out: *i32) *syntax.node = {
 // lookup missed entirely and the raw N_SPREAD leaked to pushargsrev
 // as a single $0 word). Cstage mirror: cgcall's callee_params from
 // the checker-stamped n->lhs->type (cmd/w6c/cgen.c TY_FN cu->params).
+// dotbasestructinfo — the struct registry entry for a DOT base: a
+// local ident (struct value or *struct), or a nested field chain
+// (`a.b.cb(...)` — each link a struct- or *struct-typed field). The
+// chained form previously fell to the name registry with an empty
+// module hint (the #59.8 family's last open shape) and emitted
+// CALL <leaf>(SB).
+fn dotbasestructinfo(c: *cgen, base: *syntax.node) *structinfo = {
+	if (base == nil) { return nil; };
+	if (base.kind == syntax.nkind.N_IDENT) {
+		let lc: *local = localfindnode(c, base.str);
+		if (lc == nil) { return nil; };
+		let tn: *syntax.node = lc.tnode;
+		if (tn == nil) { return nil; };
+		let sname: str;
+		sname.ptr = nil; sname.len = 0;
+		if (tn.kind == syntax.nkind.N_TNAME) { sname = tn.str; };
+		if (tn.kind == syntax.nkind.N_TPTR) {
+			if (tn.lhs != nil) {
+				if (tn.lhs.kind == syntax.nkind.N_TNAME) {
+					sname = tn.lhs.str;
+				};
+			};
+		};
+		if (sname.len == 0) { return nil; };
+		return structlookup(c, sname);
+	};
+	if (base.kind != syntax.nkind.N_DOT) { return nil; };
+	let outer: *structinfo = dotbasestructinfo(c, base.lhs);
+	if (outer == nil) { return nil; };
+	let fi: *fieldinfo = outer.fields;
+	for (fi != nil) {
+		if (syntax.streq(fi.fname, base.str)) {
+			let ft: *syntax.node = fi.tnode;
+			if (ft == nil) { return nil; };
+			if (ft.kind == syntax.nkind.N_TPTR) {
+				if (ft.lhs != nil) { ft = ft.lhs; };
+			};
+			if (ft.kind == syntax.nkind.N_TNAME) {
+				return structlookup(c, ft.str);
+			};
+			return nil;
+		};
+		fi = fi.finext;
+	};
+	return nil;
+};
+
 fn fnptrcalleetfn(c: *cgen, callee: *syntax.node) *syntax.node = {
 	if (callee == nil) { return nil; };
 	if (callee.kind == syntax.nkind.N_IDENT) {
@@ -82,25 +129,7 @@ fn fnptrcalleetfn(c: *cgen, callee: *syntax.node) *syntax.node = {
 		return nil;
 	};
 	if (callee.kind != syntax.nkind.N_DOT) { return nil; };
-	let base: *syntax.node = callee.lhs;
-	if (base == nil) { return nil; };
-	if (base.kind != syntax.nkind.N_IDENT) { return nil; };
-	let lc: *local = localfindnode(c, base.str);
-	if (lc == nil) { return nil; };
-	let tn: *syntax.node = lc.tnode;
-	if (tn == nil) { return nil; };
-	let sname: str;
-	sname.ptr = nil; sname.len = 0;
-	if (tn.kind == syntax.nkind.N_TNAME) { sname = tn.str; };
-	if (tn.kind == syntax.nkind.N_TPTR) {
-		if (tn.lhs != nil) {
-			if (tn.lhs.kind == syntax.nkind.N_TNAME) {
-				sname = tn.lhs.str;
-			};
-		};
-	};
-	if (sname.len == 0) { return nil; };
-	let si: *structinfo = structlookup(c, sname);
+	let si: *structinfo = dotbasestructinfo(c, callee.lhs);
 	if (si == nil) { return nil; };
 	let fi: *fieldinfo = si.fields;
 	for (fi != nil) {

test/wcc/data/fnptrfield_chain/case.ww

@@ -0,0 +1,27 @@
+//ww:run-exit 36
+package main;
+
+// A call through a chained-DOT fn-ptr field (a.b.cb(...)). The wwstage
+// callee resolver only accepted an N_IDENT base, so the chained shape
+// fell to the name registry with an empty module hint and emitted
+// CALL cb(SB) — the last open shape of the #59.8 name-keyed family.
+
+type bstr = struct {
+	cb: *fn(x: i32) i32,
+	pad: i32,
+};
+
+type astr = struct {
+	n: i32,
+	b: bstr,
+};
+
+fn twice(x: i32) i32 = { return x * 2; };
+
+fn main() i32 = {
+	let a: astr;
+	a.n = 1;
+	a.b.cb = &twice;
+	a.b.pad = 2;
+	return a.b.cb(20) + a.n + a.b.pad - 7;
+};