From 5f9af3f5941074db49849d02bf6e178b2079f08b Mon Sep 17 00:00:00 2001
From: yuyi <yuyi98@163.com>
Date: Thu, 4 Mar 2021 18:39:39 +0800
Subject: [PATCH] cgen: fix for_in array of fixed_array (fix #9098) (#9099)

---
 vlib/v/gen/c/cgen.v                           |  4 +++
 .../for_in_containers_of_fixed_array_test.v   | 25 +++++++++++++++++++
 2 files changed, 29 insertions(+)
 create mode 100644 vlib/v/tests/for_in_containers_of_fixed_array_test.v

diff --git a/vlib/v/gen/c/cgen.v b/vlib/v/gen/c/cgen.v
index 75dc9f2386..8138fe306b 100644
--- a/vlib/v/gen/c/cgen.v
+++ b/vlib/v/gen/c/cgen.v
@@ -1385,6 +1385,10 @@ fn (mut g Gen) for_in_stmt(node ast.ForInStmt) {
 				g.write('\t')
 				g.write_fn_ptr_decl(val_sym.info as table.FnType, c_name(node.val_var))
 				g.writeln(' = ((voidptr*)$tmp${op_field}data)[$i];')
+			} else if val_sym.kind == .array_fixed && !node.val_is_mut {
+				right := '(($styp*)$tmp${op_field}data)[$i]'
+				g.writeln('\t$styp ${c_name(node.val_var)};')
+				g.writeln('\tmemcpy(*($styp*)${c_name(node.val_var)}, (byte*)$right, sizeof($styp));')
 			} else {
 				// If val is mutable (pointer behind the scenes), we need to generate
 				// `int* val = ((int*)arr.data) + i;`
diff --git a/vlib/v/tests/for_in_containers_of_fixed_array_test.v b/vlib/v/tests/for_in_containers_of_fixed_array_test.v
new file mode 100644
index 0000000000..6c04b84fa8
--- /dev/null
+++ b/vlib/v/tests/for_in_containers_of_fixed_array_test.v
@@ -0,0 +1,25 @@
+fn test_for_in_containers_of_fixed_array() {
+	mut rets := []string{}
+	arr := [][2]int{len: 3}
+
+	for pair in arr {
+		println(pair)
+		rets << '$pair'
+	}
+	assert rets[0] == '[0, 0]'
+	assert rets[1] == '[0, 0]'
+	assert rets[2] == '[0, 0]'
+}
+
+fn test_for_mut_in_containers_of_fixed_array() {
+	mut rets := []string{}
+	mut arr := [][2]int{len: 3}
+
+	for mut pair in arr {
+		println(pair)
+		rets << '$pair'
+	}
+	assert rets[0] == '[0, 0]'
+	assert rets[1] == '[0, 0]'
+	assert rets[2] == '[0, 0]'
+}