From 4ac610c022a47d7243ef99a5c56967192e014651 Mon Sep 17 00:00:00 2001
From: wenxuanjun <41050170+wenxuanjun@users.noreply.github.com>
Date: Sat, 28 Mar 2026 21:07:47 +0800
Subject: [PATCH] cgen: avoid builtin print handling for user print fns
 (#26781)

---
 vlib/v/gen/c/fn.v                                          | 5 ++++-
 .../gen/c/testdata/no_builtin_print_name_clash.c.must_have | 2 ++
 vlib/v/gen/c/testdata/no_builtin_print_name_clash.vv       | 7 +++++++
 3 files changed, 13 insertions(+), 1 deletion(-)
 create mode 100644 vlib/v/gen/c/testdata/no_builtin_print_name_clash.c.must_have
 create mode 100644 vlib/v/gen/c/testdata/no_builtin_print_name_clash.vv

diff --git a/vlib/v/gen/c/fn.v b/vlib/v/gen/c/fn.v
index a298a27a7..54736ee8b 100644
--- a/vlib/v/gen/c/fn.v
+++ b/vlib/v/gen/c/fn.v
@@ -2082,7 +2082,7 @@ fn (mut g Gen) fn_call(node ast.CallExpr) {
 			}
 		}
 	}
-	is_print := node.kind in [.print, .println, .eprint, .eprintln, .panic]
+	mut is_print := !is_selector_call && node.kind in [.print, .println, .eprint, .eprintln, .panic]
 	print_method := name
 	is_json_encode := node.kind == .json_encode
 	is_json_encode_pretty := node.kind == .json_encode_pretty
@@ -2186,6 +2186,9 @@ fn (mut g Gen) fn_call(node ast.CallExpr) {
 			if func.mod == 'builtin' && !name.starts_with('builtin__') && node.language != .c {
 				name = 'builtin__${name}'
 			}
+			is_print = is_print && func.mod == 'builtin'
+		} else {
+			is_print = false
 		}
 	}
 	if node.is_fn_a_const {
diff --git a/vlib/v/gen/c/testdata/no_builtin_print_name_clash.c.must_have b/vlib/v/gen/c/testdata/no_builtin_print_name_clash.c.must_have
new file mode 100644
index 000000000..ea21cac6b
--- /dev/null
+++ b/vlib/v/gen/c/testdata/no_builtin_print_name_clash.c.must_have
@@ -0,0 +1,2 @@
+void main__print(voidptr fmt, ... );
+main__print("\n");
diff --git a/vlib/v/gen/c/testdata/no_builtin_print_name_clash.vv b/vlib/v/gen/c/testdata/no_builtin_print_name_clash.vv
new file mode 100644
index 000000000..b4b0371b4
--- /dev/null
+++ b/vlib/v/gen/c/testdata/no_builtin_print_name_clash.vv
@@ -0,0 +1,7 @@
+// vtest vflags: -no-builtin
+@[markused]
+pub fn error() {
+	print(c'\n')
+}
+
+pub fn print(fmt voidptr, ...) {}
-- 
2.39.5