From 72b48047b5ac87de9be9fda619df74d8e4802d55 Mon Sep 17 00:00:00 2001
From: Felipe Pena <felipensp@gmail.com>
Date: Wed, 9 Oct 2024 16:48:28 -0300
Subject: [PATCH] checker: add scope validation for struct (fix #22437)
 (#22449)

---
 vlib/v/ast/types.v                        |  4 +++-
 vlib/v/checker/struct.v                   |  5 +++++
 vlib/v/checker/tests/struct_scope_err.out |  7 +++++++
 vlib/v/checker/tests/struct_scope_err.vv  | 18 ++++++++++++++++++
 vlib/v/parser/struct.v                    |  2 ++
 5 files changed, 35 insertions(+), 1 deletion(-)
 create mode 100644 vlib/v/checker/tests/struct_scope_err.out
 create mode 100644 vlib/v/checker/tests/struct_scope_err.vv

diff --git a/vlib/v/ast/types.v b/vlib/v/ast/types.v
index a7381eec8..20e8c3d1b 100644
--- a/vlib/v/ast/types.v
+++ b/vlib/v/ast/types.v
@@ -158,7 +158,9 @@ pub mut:
 @[minify]
 pub struct Struct {
 pub:
-	attrs []Attr
+	attrs    []Attr
+	scope    &Scope = unsafe { nil }
+	is_local bool
 pub mut:
 	embeds         []Type
 	fields         []StructField
diff --git a/vlib/v/checker/struct.v b/vlib/v/checker/struct.v
index 89e3ebb17..3b03fdfd4 100644
--- a/vlib/v/checker/struct.v
+++ b/vlib/v/checker/struct.v
@@ -441,6 +441,11 @@ fn (mut c Checker) struct_init(mut node ast.StructInit, is_field_zero_struct_ini
 	mut old_cur_struct_generic_types := []ast.Type{}
 	mut old_cur_struct_concrete_types := []ast.Type{}
 	if struct_sym.info is ast.Struct {
+		if struct_sym.info.is_local && struct_sym.info.scope != unsafe { nil }
+			&& !struct_sym.info.scope.contains(node.pos.pos) {
+			c.error('struct `${struct_sym.name}` was declared in a local scope outside current scope',
+				node.pos)
+		}
 		// check if the generic param types have been defined
 		for ct in struct_sym.info.concrete_types {
 			ct_sym := c.table.sym(ct)
diff --git a/vlib/v/checker/tests/struct_scope_err.out b/vlib/v/checker/tests/struct_scope_err.out
new file mode 100644
index 000000000..2c80cb349
--- /dev/null
+++ b/vlib/v/checker/tests/struct_scope_err.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/struct_scope_err.vv:16:8: error: struct `Foobar` was declared in a local scope outside current scope
+   14 | 
+   15 | fn x() {
+   16 |     fb := Foobar{7, 8}
+      |           ~~~~~~~~~~~~
+   17 |     println(fb.bar)
+   18 | }
diff --git a/vlib/v/checker/tests/struct_scope_err.vv b/vlib/v/checker/tests/struct_scope_err.vv
new file mode 100644
index 000000000..f5e70858d
--- /dev/null
+++ b/vlib/v/checker/tests/struct_scope_err.vv
@@ -0,0 +1,18 @@
+fn main() {
+
+	struct Foobar {
+		foo int
+		bar int
+	}
+
+	if true {
+		fb := Foobar{5, 6}
+		println(fb.foo)
+		x()
+	}
+}
+
+fn x() {
+	fb := Foobar{7, 8}
+	println(fb.bar)
+}
diff --git a/vlib/v/parser/struct.v b/vlib/v/parser/struct.v
index 7e0050929..4796867ec 100644
--- a/vlib/v/parser/struct.v
+++ b/vlib/v/parser/struct.v
@@ -370,6 +370,8 @@ fn (mut p Parser) struct_decl(is_anon bool) ast.StructDecl {
 			generic_types: generic_types
 			attrs:         attrs
 			is_anon:       is_anon
+			is_local:      p.inside_fn
+			scope:         p.scope
 		}
 		is_pub:   is_pub
 	}
-- 
2.39.5