cgen: fix update expr with embed fixed array with multiple dimensions (…

…fix vlang#23048) (vlang#23049)

vlib/v/gen/c/array.v

@@ -1657,12 +1657,17 @@ fn (mut g Gen) fixed_array_update_expr_field(expr_str string, field_type ast.Typ
 			g.write('}')
 		}
 	}
+	embed_field := if is_update_embed {
+		g.get_embed_field_name(field_type, field_name)
+	} else {
+		''
+	}
 	for i in 0 .. size {
 		if elem_sym.info is ast.ArrayFixed {
 			init_str := if g.inside_array_fixed_struct {
 				'${expr_str}'
 			} else {
-				'${expr_str}->${c_name(field_name)}[${i}]'
+				'${expr_str}->${embed_field}${c_name(field_name)}[${i}]'
 			}
 			g.fixed_array_update_expr_field(init_str, field_type, field_name, is_auto_deref,
 				elem_sym.info.elem_type, elem_sym.info.size, is_update_embed)
@@ -1675,26 +1680,11 @@ fn (mut g Gen) fixed_array_update_expr_field(expr_str string, field_type ast.Typ
 					g.write('.')
 				}
 				if is_update_embed {
-					update_sym := g.table.sym(field_type)
-					_, embeds := g.table.find_field_from_embeds(update_sym, field_name) or {
-						ast.StructField{}, []ast.Type{}
-					}
-					for embed in embeds {
-						esym := g.table.sym(embed)
-						ename := esym.embed_name()
-						g.write(ename)
-						if embed.is_ptr() {
-							g.write('->')
-						} else {
-							g.write('.')
-						}
-					}
+					g.write(embed_field)
 				}
 				g.write(c_name(field_name))
 			}
-			if !expr_str.starts_with('(') && !expr_str.starts_with('{') {
-				g.write('[${i}]')
-			}
+			g.write('[${i}]')
 		}
 		if i != size - 1 {
 			g.write(', ')

vlib/v/gen/c/struct.v

@@ -326,20 +326,7 @@ fn (mut g Gen) struct_init(node ast.StructInit) {
 						g.write('.')
 					}
 					if node.is_update_embed {
-						update_sym := g.table.sym(node.update_expr_type)
-						_, embeds := g.table.find_field_from_embeds(update_sym, field.name) or {
-							ast.StructField{}, []ast.Type{}
-						}
-						for embed in embeds {
-							esym := g.table.sym(embed)
-							ename := esym.embed_name()
-							g.write(ename)
-							if embed.is_ptr() {
-								g.write('->')
-							} else {
-								g.write('.')
-							}
-						}
+						g.write(g.get_embed_field_name(node.update_expr_type, field.name))
 					}
 					g.write(c_name(field.name))
 				}
@@ -402,6 +389,24 @@ fn (mut g Gen) struct_init(node ast.StructInit) {
 	}
 }
 
+fn (mut g Gen) get_embed_field_name(field_type ast.Type, field_name string) string {
+	update_sym := g.table.sym(field_type)
+	_, embeds := g.table.find_field_from_embeds(update_sym, field_name) or {
+		ast.StructField{}, []ast.Type{}
+	}
+	mut s := ''
+	for embed in embeds {
+		esym := g.table.sym(embed)
+		ename := esym.embed_name()
+		if embed.is_ptr() {
+			s += '${ename}->'
+		} else {
+			s += '${ename}.'
+		}
+	}
+	return s
+}
+
 fn (mut g Gen) zero_struct_field(field ast.StructField) bool {
 	old_inside_cast_in_heap := g.inside_cast_in_heap
 	g.inside_cast_in_heap = 0

vlib/v/tests/fixed_array_2_dims_embed_test.v

@@ -0,0 +1,48 @@
+module main
+
+type Mat4 = [16]f32
+type Mat14 = [1][16]f32
+
+@[heap]
+struct GameObject {
+mut:
+	transform  Mat4
+	transform2 Mat14
+}
+
+@[heap]
+struct Ship {
+	GameObject
+}
+
+fn Ship.new() &Ship {
+	mut ship := &Ship{}
+	return ship
+}
+
+fn (mut ship Ship) clone() &Ship {
+	return &Ship{
+		...ship
+	}
+}
+
+fn test_main() {
+	mut v1 := Ship.new()
+	v1.transform[0] = 1.0
+	v1.transform[15] = 2.0
+	v1.transform2[0][0] = 1.0
+	v1.transform2[0][15] = 2.0
+	mut v2 := v1.clone()
+	eprintln('v1=${v1.transform}\nv2=${v2.transform}')
+	assert v1.transform == v2.transform
+	assert v1.transform2 == v2.transform2
+	assert v1.transform[0] == 1.0
+	assert v2.transform[0] == 1.0
+	assert v1.transform[15] == 2.0
+	assert v2.transform[15] == 2.0
+
+	assert v1.transform2[0][0] == 1.0
+	assert v2.transform2[0][0] == 1.0
+	assert v1.transform2[0][15] == 2.0
+	assert v2.transform2[0][15] == 2.0
+}