From 5dd28cf941cd814da644407dd6441fdc8e592ac0 Mon Sep 17 00:00:00 2001
From: Felipe Pena <felipensp@gmail.com>
Date: Sat, 18 Jan 2025 05:29:52 -0300
Subject: [PATCH] markused: fix markused auto str detection (fix #23501)
 (#23503)

---
 vlib/v/checker/used_features.v                |  4 +++-
 vlib/v/tests/skip_unused/auto_str.run.out     |  3 +++
 .../skip_unused/auto_str.skip_unused.run.out  |  3 +++
 vlib/v/tests/skip_unused/auto_str.vv          | 20 +++++++++++++++++++
 4 files changed, 29 insertions(+), 1 deletion(-)
 create mode 100644 vlib/v/tests/skip_unused/auto_str.run.out
 create mode 100644 vlib/v/tests/skip_unused/auto_str.skip_unused.run.out
 create mode 100644 vlib/v/tests/skip_unused/auto_str.vv

diff --git a/vlib/v/checker/used_features.v b/vlib/v/checker/used_features.v
index d024da99b..4a73831c1 100644
--- a/vlib/v/checker/used_features.v
+++ b/vlib/v/checker/used_features.v
@@ -125,7 +125,9 @@ fn (mut c Checker) markused_call_expr(mut node ast.CallExpr) {
 
 fn (mut c Checker) markused_fn_call(mut node ast.CallExpr) {
 	if !c.is_builtin_mod && c.mod != 'math.bits' && node.args[0].expr !is ast.StringLiteral {
-		if !c.table.sym(c.unwrap_generic(node.args[0].typ)).has_method('str') {
+		if (node.args[0].expr is ast.CallExpr && node.args[0].expr.is_method
+			&& node.args[0].expr.name == 'str')
+			|| !c.table.sym(c.unwrap_generic(node.args[0].typ)).has_method('str') {
 			c.table.used_features.auto_str = true
 		} else {
 			if node.args[0].typ.has_option_or_result() {
diff --git a/vlib/v/tests/skip_unused/auto_str.run.out b/vlib/v/tests/skip_unused/auto_str.run.out
new file mode 100644
index 000000000..9e932fecc
--- /dev/null
+++ b/vlib/v/tests/skip_unused/auto_str.run.out
@@ -0,0 +1,3 @@
+&TreeTwo{
+    Tree: 
+}
diff --git a/vlib/v/tests/skip_unused/auto_str.skip_unused.run.out b/vlib/v/tests/skip_unused/auto_str.skip_unused.run.out
new file mode 100644
index 000000000..9e932fecc
--- /dev/null
+++ b/vlib/v/tests/skip_unused/auto_str.skip_unused.run.out
@@ -0,0 +1,3 @@
+&TreeTwo{
+    Tree: 
+}
diff --git a/vlib/v/tests/skip_unused/auto_str.vv b/vlib/v/tests/skip_unused/auto_str.vv
new file mode 100644
index 000000000..8989ce3af
--- /dev/null
+++ b/vlib/v/tests/skip_unused/auto_str.vv
@@ -0,0 +1,20 @@
+module main
+
+pub struct Tree {}
+
+pub fn (tree &Tree) str() string {
+	return ''
+}
+
+pub struct TreeTwo {
+	Tree
+}
+
+pub fn TreeTwo.from_string(tree_string string) !&TreeTwo {
+	return &TreeTwo{}
+}
+
+fn main() {
+	tree := TreeTwo.from_string('') or { panic(err) }
+	println(tree.str())
+}
-- 
2.39.5