ast, parser, checker: check struct implements non interface type

vlang · Sep 14, 2024 · 8e915f2 · 8e915f2
1 parent 26ab7d4
commit 8e915f2
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Showing 5 changed files with 39 additions and 20 deletions.
diff --git a/vlib/v/ast/ast.v b/vlib/v/ast/ast.v
@@ -417,8 +417,9 @@ pub:
 	end_comments []Comment
 	embeds       []Embed
 
-	is_implements    bool
-	implements_types []Type
+	is_implements        bool
+	implements_types     []Type
+	implements_types_pos token.Pos
 pub mut:
 	fields []StructField
 }

diff --git a/vlib/v/checker/struct.v b/vlib/v/checker/struct.v
@@ -334,6 +334,10 @@ fn (mut c Checker) struct_decl(mut node ast.StructDecl) {
 		// cgen error if I use `println(sym)` without handling the option with `or{}`
 		struct_type := c.table.find_type_idx(node.name) // or { panic(err) }
 		for t in node.implements_types {
+			t_sym := c.table.sym(t)
+			if t_sym.kind != .interface_ {
+				c.error('`${t_sym.name}` is not an interface type', node.implements_types_pos)
+			}
 			c.type_implements(struct_type, t, node.pos)
 		}
 	}

diff --git a/vlib/v/checker/tests/struct_implements_non_interface_err.out b/vlib/v/checker/tests/struct_implements_non_interface_err.out
@@ -0,0 +1,5 @@
+vlib/v/checker/tests/struct_implements_non_interface_err.vv:1:26: error: `Abcde` is not an interface type
+    1 | struct Walker implements Abcde  {
+      |                          ~~~~~
+    2 |     aaa  string
+    3 | }
diff --git a/vlib/v/checker/tests/struct_implements_non_interface_err.vv b/vlib/v/checker/tests/struct_implements_non_interface_err.vv
@@ -0,0 +1,5 @@
+struct Walker implements Abcde  {
+	aaa  string
+}
+
+fn main() {}
diff --git a/vlib/v/parser/struct.v b/vlib/v/parser/struct.v
@@ -97,16 +97,19 @@ fn (mut p Parser) struct_decl(is_anon bool) ast.StructDecl {
 	mut implements_types := []ast.Type{cap: 3} // ast.void_type
 	mut last_line := p.prev_tok.pos().line_nr + 1
 	mut end_comments := []ast.Comment{}
+	mut implements_types_pos := token.Pos{}
 	if !no_body {
 		if p.tok.kind == .key_implements {
 			is_implements = true
+			start_implements_pos := p.peek_tok.pos()
 			for {
 				p.next()
 				implements_types << p.parse_type()
 				if p.tok.kind != .comma {
 					break
 				}
 			}
+			implements_types_pos = start_implements_pos.extend(p.prev_tok.pos())
 		}
 		p.check(.lcbr)
 		pre_comments << p.eat_comments()
@@ -383,24 +386,25 @@ fn (mut p Parser) struct_decl(is_anon bool) ast.StructDecl {
 	}
 	p.expr_mod = ''
 	return ast.StructDecl{
-		name:             name
-		is_pub:           is_pub
-		fields:           ast_fields
-		pos:              start_pos.extend_with_last_line(name_pos, last_line)
-		mut_pos:          mut_pos
-		pub_pos:          pub_pos
-		pub_mut_pos:      pub_mut_pos
-		global_pos:       global_pos
-		module_pos:       module_pos
-		language:         language
-		is_union:         is_union
-		attrs:            if is_anon { []ast.Attr{} } else { attrs } // anon structs can't have attributes
-		pre_comments:     pre_comments
-		end_comments:     end_comments
-		generic_types:    generic_types
-		embeds:           embeds
-		is_implements:    is_implements
-		implements_types: implements_types
+		name:                 name
+		is_pub:               is_pub
+		fields:               ast_fields
+		pos:                  start_pos.extend_with_last_line(name_pos, last_line)
+		mut_pos:              mut_pos
+		pub_pos:              pub_pos
+		pub_mut_pos:          pub_mut_pos
+		global_pos:           global_pos
+		module_pos:           module_pos
+		language:             language
+		is_union:             is_union
+		attrs:                if is_anon { []ast.Attr{} } else { attrs } // anon structs can't have attributes
+		pre_comments:         pre_comments
+		end_comments:         end_comments
+		generic_types:        generic_types
+		embeds:               embeds
+		is_implements:        is_implements
+		implements_types:     implements_types
+		implements_types_pos: implements_types_pos
 	}
 }