From 6553d60e915c2ee89ad1b9a410432e516ba6f0a7 Mon Sep 17 00:00:00 2001
From: Hojun-Cho <ghwns6743@gmail.com>
Date: Sat, 8 Aug 2026 02:28:33 +0900
Subject: [PATCH] cgen: peel *fn field types for local struct-field callees
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fnptrcalleetfn's N_DOT arm accepted only a bare N_TFN field tnode, so
a call through a field declared `cb: *fn(...)` missed, fell through to
the name registry, and emitted CALL cb(SB) — an undefined symbol
(loud at link; cstage calls the stamped ptr-to-fn indirectly). Same
TPTR peel the N_IDENT arm already had. Fixture fnptrfield_call covers
the by-value and via-pointer shapes; corpus pin 1478/2956.
---
 docs/test-system-v2.md                |  4 ++--
 internal/wwfixture/types.ww           |  8 ++++----
 selfhost/cmd/wcc/cgenutil.ww          | 12 ++++++++++++
 test/wcc/data/fnptrfield_call/case.ww | 22 ++++++++++++++++++++++
 4 files changed, 40 insertions(+), 6 deletions(-)
 create mode 100644 test/wcc/data/fnptrfield_call/case.ww

diff --git a/docs/test-system-v2.md b/docs/test-system-v2.md
index b49b27f0..e1f9d96a 100644
--- a/docs/test-system-v2.md
+++ b/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 1,477 fixtures and 2,954 C/WW cells:
+The live declarative compiler corpus has 1,478 fixtures and 2,956 C/WW cells:
 335 expected rejections (311 shared and 24 stage-specific), 17 compile-only
-successes, 191 exit-zero programs, and 934 explicit-exit programs.
+successes, 191 exit-zero programs, and 935 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
diff --git a/internal/wwfixture/types.ww b/internal/wwfixture/types.ww
index 7906f5c6..5fa66bd7 100644
--- a/internal/wwfixture/types.ww
+++ b/internal/wwfixture/types.ww
@@ -1,13 +1,13 @@
 package wwfixture;
 
 def protocolversion: i32 = 1;
-def corpuscount: i32 = 1477;
+def corpuscount: i32 = 1478;
 def errorcount: i32 = 335;
 def compilecount: i32 = 17;
 def runcount: i32 = 191;
-def runexitcount: i32 = 934;
-def nativecount: i32 = 2954;
-def corpushash: str = "64258f4de9ac7d71c4ad6221dd2ae7338a38cd5c620fc4ce22c1105021559e83";
+def runexitcount: i32 = 935;
+def nativecount: i32 = 2956;
+def corpushash: str = "2ac2342a80c4148968250bf4ce93852b78cdefb6af96622fa533eea4a68837c6";
 
 type directive = enum i32 {
 	ERROR = 0,
diff --git a/selfhost/cmd/wcc/cgenutil.ww b/selfhost/cmd/wcc/cgenutil.ww
index 18f0e35a..456e2030 100644
--- a/selfhost/cmd/wcc/cgenutil.ww
+++ b/selfhost/cmd/wcc/cgenutil.ww
@@ -108,6 +108,18 @@ fn fnptrcalleetfn(c: *cgen, callee: *syntax.node) *syntax.node = {
 			let ft: *syntax.node = fi.tnode;
 			if (ft != nil) {
 				if (ft.kind == syntax.nkind.N_TFN) { return ft; };
+				// `cb: *fn(...)` — same TPTR peel as the N_IDENT
+				// arm above; without it the field-call fell through
+				// to the name registry and emitted CALL <leaf>(SB)
+				// (undefined symbol — loud at link, but cstage
+				// resolves the stamped ptr-to-fn and calls indirect).
+				if (ft.kind == syntax.nkind.N_TPTR) {
+					if (ft.lhs != nil) {
+						if (ft.lhs.kind == syntax.nkind.N_TFN) {
+							return ft.lhs;
+						};
+					};
+				};
 			};
 			return nil;
 		};
diff --git a/test/wcc/data/fnptrfield_call/case.ww b/test/wcc/data/fnptrfield_call/case.ww
new file mode 100644
index 00000000..4eeff68a
--- /dev/null
+++ b/test/wcc/data/fnptrfield_call/case.ww
@@ -0,0 +1,22 @@
+//ww:run-exit 36
+package main;
+
+// A call through a struct field declared `*fn(...)`, by value and via
+// pointer. The wwstage fnptrcalleetfn N_DOT arm lacked the TPTR peel
+// its N_IDENT arm had, so the callee fell through to the name registry
+// and emitted CALL cb(SB) — an undefined symbol.
+
+type cbs = struct {
+	cb: *fn(x: i32) i32,
+	k:  i32,
+};
+
+fn twice(x: i32) i32 = { return x * 2; };
+
+fn main() i32 = {
+	let o: cbs;
+	o.cb = &twice;
+	o.k = 4;
+	let p: *cbs = &o;
+	return o.cb(10) + p.cb(6) + o.k;
+};