cgen: fix map_complex_high_order_fixed_array (#8329)

vlib/v/gen/cgen.v

@@ -65,6 +65,7 @@ mut:
 	is_sql              bool // Inside `sql db{}` statement, generating sql instead of C (e.g. `and` instead of `&&` etc)
 	is_shared           bool // for initialization of hidden mutex in `[rw]shared` literals
 	is_vlines_enabled   bool // is it safe to generate #line directives when -g is passed
+	array_set_pos       int
 	vlines_path         string   // set to the proper path for generating #line directives
 	optionals           []string // to avoid duplicates TODO perf, use map
 	chan_pop_optionals  []string // types for `x := <-ch or {...}`
@@ -1976,57 +1977,28 @@ fn (mut g Gen) gen_assign_stmt(assign_stmt ast.AssignStmt) {
 			}
 		} else if is_fixed_array_init && assign_stmt.op == .assign {
 			right := val as ast.ArrayInit
-			if right.has_val {
+			v_var := g.new_tmp_var()
-				for j, expr in right.exprs {
+			arr_typ := styp.trim('*')
-					if !is_decl && left is ast.Ident
+			g.write('$arr_typ $v_var = ')
-						&& g.for_in_mul_val_name == (left as ast.Ident).name {
+			g.expr(right)
-						g.write('(*')
-						g.expr(left)
-						g.write(')')
-					} else {
-						g.expr(left)
-					}
-					if g.is_array_set {
-						g.out.go_back(2)
-					} else {
-						g.write('[$j] = ')
-					}
-					g.expr(expr)
-					if g.is_array_set {
-						g.writeln(')')
-						g.is_array_set = false
-					} else {
 			g.writeln(';')
-					}
+			pos := g.out.len
-				}
-			} else {
-				fixed_array := right_sym.info as table.ArrayFixed
-				for j in 0 .. fixed_array.size {
-					if !is_decl && left is ast.Ident
-						&& g.for_in_mul_val_name == (left as ast.Ident).name {
-						g.write('(*')
 			g.expr(left)
-						g.write(')')
+
-					} else {
+			if g.is_array_set && g.array_set_pos > 0 {
-						g.expr(left)
+				g.out.go_back_to(g.array_set_pos)
-					}
+				g.write(', &$v_var)')
-					if g.is_array_set {
-						g.out.go_back(2)
-					} else {
-						g.write('[$j] = ')
-					}
-					if right.has_default {
-						g.expr(right.default_expr)
-					} else {
-						g.write(g.type_default(right.elem_type))
-					}
-					if g.is_array_set {
-						g.writeln(')')
 				g.is_array_set = false
+				g.array_set_pos = 0
 			} else {
-						g.writeln(';')
+				g.out.go_back_to(pos)
-					}
+				is_var_mut := !is_decl && left is ast.Ident
-				}
+					&& g.for_in_mul_val_name == (left as ast.Ident).name
+				addr := if is_var_mut { '' } else { '&' }
+				g.writeln('')
+				g.write('memcpy($addr')
+				g.expr(left)
+				g.writeln(', &$v_var, sizeof($arr_typ));')
 			}
 			g.is_assign_lhs = false
 		} else {
@@ -4271,6 +4243,7 @@ fn (mut g Gen) index_expr(node ast.IndexExpr) {
 					if elem_typ.kind == .function {
 						g.write(', &(voidptr[]) { ')
 					} else {
+						g.array_set_pos = g.out.len
 						g.write(', &($elem_type_str[]) { ')
 					}
 					if g.assign_op != .assign && info.value_type != table.string_type {

vlib/v/tests/map_complex_fixed_array_test.v

@@ -17,3 +17,12 @@ fn test_innermost_value_of_map_fixed_array() {
 	assert m['foo'][0][0]['bar'] == 1
 	assert '${m['foo'][0][0]['bar']}' == '1'
 }
+
+fn test_complex_map_high_order_fixed_array() {
+	mut m := {'foo': [[{'a': 1}]!]!, 'bar': [[{'b': 2}]!]!}
+	for _, mut j in m {
+		j = [[{'c': 3}]!]!
+	}
+	println(m)
+	assert '$m' == "{'foo': [[{'c': 3}]], 'bar': [[{'c': 3}]]}"
+}