From d7d38926e2bdfc5c2e1871f64edcb8c1eea94b8a Mon Sep 17 00:00:00 2001
From: shove70 <shove@163.com>
Date: Thu, 10 Aug 2023 14:06:54 +0800
Subject: [PATCH] cgen: fix spawn call fn struct field(fix #18862)

---
 vlib/v/gen/c/spawn_and_go.v                    | 14 +++++++++++---
 .../c/testdata/spawn_call_fn_struct_field.out  |  2 ++
 .../c/testdata/spawn_call_fn_struct_field.vv   | 18 ++++++++++++++++++
 3 files changed, 31 insertions(+), 3 deletions(-)
 create mode 100644 vlib/v/gen/c/testdata/spawn_call_fn_struct_field.out
 create mode 100644 vlib/v/gen/c/testdata/spawn_call_fn_struct_field.vv

diff --git a/vlib/v/gen/c/spawn_and_go.v b/vlib/v/gen/c/spawn_and_go.v
index b3d36ed50f..7c620e0f88 100644
--- a/vlib/v/gen/c/spawn_and_go.v
+++ b/vlib/v/gen/c/spawn_and_go.v
@@ -91,7 +91,8 @@ fn (mut g Gen) spawn_and_go_expr(node ast.SpawnExpr, mode SpawnGoMode) {
 	} else {
 		name
 	}
-	if !(expr.is_method && g.table.sym(expr.receiver_type).kind == .interface_) {
+	if !(expr.is_method && (g.table.sym(expr.receiver_type).kind == .interface_
+		|| (g.table.sym(expr.receiver_type).kind == .struct_ && expr.is_field))) {
 		g.writeln('${arg_tmp_var}${dot}fn = ${fn_name};')
 	}
 	if expr.is_method {
@@ -250,7 +251,9 @@ fn (mut g Gen) spawn_and_go_expr(node ast.SpawnExpr, mode SpawnGoMode) {
 				}
 			}
 		}
-		g.type_definitions.writeln('\t${fn_var};')
+		if fn_var != '' {
+			g.type_definitions.writeln('\t${fn_var};')
+		}
 		if expr.is_method {
 			styp := g.typ(expr.receiver_type)
 			g.type_definitions.writeln('\t${styp} arg0;')
@@ -298,11 +301,16 @@ fn (mut g Gen) spawn_and_go_expr(node ast.SpawnExpr, mode SpawnGoMode) {
 				g.gowrappers.write_string('${idot}_typ]._method_${mname}(')
 				g.gowrappers.write_string('arg->arg0')
 				g.gowrappers.write_string('${idot}_object')
+			} else if typ_sym.kind == .struct_ && expr.is_field {
+				g.gowrappers.write_string('arg->arg0')
+				idot := if expr.left_type.is_ptr() { '->' } else { '.' }
+				mname := c_name(expr.name)
+				g.gowrappers.write_string('${idot}${mname}(')
 			} else {
 				g.gowrappers.write_string('arg->fn(')
 				g.gowrappers.write_string('arg->arg0')
 			}
-			if expr.args.len > 0 {
+			if expr.args.len > 0 && (typ_sym.kind != .struct_ || !expr.is_field) {
 				g.gowrappers.write_string(', ')
 			}
 		} else {
diff --git a/vlib/v/gen/c/testdata/spawn_call_fn_struct_field.out b/vlib/v/gen/c/testdata/spawn_call_fn_struct_field.out
new file mode 100644
index 0000000000..317e9677c3
--- /dev/null
+++ b/vlib/v/gen/c/testdata/spawn_call_fn_struct_field.out
@@ -0,0 +1,2 @@
+hello
+hello
diff --git a/vlib/v/gen/c/testdata/spawn_call_fn_struct_field.vv b/vlib/v/gen/c/testdata/spawn_call_fn_struct_field.vv
new file mode 100644
index 0000000000..a4604f5551
--- /dev/null
+++ b/vlib/v/gen/c/testdata/spawn_call_fn_struct_field.vv
@@ -0,0 +1,18 @@
+struct Foo {
+mut:
+	func1 fn (int) = unsafe { nil }
+	func2 fn (int) = do
+}
+
+fn do(a int) {
+	println('hello')
+}
+
+mut foo := Foo{}
+
+foo.func1 = do
+mut p := spawn foo.func1(1)
+p.wait()
+
+p = spawn foo.func2(1)
+p.wait()