cgen: fix mutable array arguments (#5769)

vlib/builtin/array_test.v

@@ -910,3 +910,25 @@ fn test_array_in_mut() {
 	array_in_mut(mut a)
 	assert a == [2,2]
 }
+
+// test array delete in function with mut argument
+fn delete_nums(mut arr []int) {
+	arr.delete(0)
+}
+
+fn test_array_delete_in_mut() {
+	mut nums := [1, 2, 3]
+	delete_nums(mut nums)
+	assert nums == [2, 3]
+}
+
+// test array add in function with mut argument
+fn add_nums(mut arr []int) {
+	arr << 4
+}
+
+fn test_array_add_in_mut() {
+	mut nums := [1, 2, 3]
+	add_nums(mut nums)
+	assert nums == [1, 2, 3, 4]
+}

vlib/crypto/aes/aes_cbc.v

@@ -46,7 +46,8 @@ pub fn new_cbc(b AesCipher, iv []byte) AesCbc {
 
 pub fn (x &AesCbc) block_size() int { return x.block_size }
 
-pub fn (x &AesCbc) encrypt_blocks(mut dst []byte, src_ []byte) {
+pub fn (x &AesCbc) encrypt_blocks(mut dst_ []byte, src_ []byte) {
+	mut dst := *dst_
 	mut src := src_
 	if src.len%x.block_size != 0 {
 		panic('crypto.cipher: input not full blocks')
@@ -54,7 +55,7 @@ pub fn (x &AesCbc) encrypt_blocks(mut dst []byte, src_ []byte) {
 	if dst.len < src.len {
 		panic('crypto.cipher: output smaller than input')
 	}
-	if subtle.inexact_overlap((*dst)[..src.len], src_) {
+	if subtle.inexact_overlap(dst[..src.len], src_) {
 		panic('crypto.cipher: invalid buffer overlap')
 	}
 
@@ -62,17 +63,17 @@ pub fn (x &AesCbc) encrypt_blocks(mut dst []byte, src_ []byte) {
 
 	for src.len > 0 {
 		// Write the xor to dst, then encrypt in place.
-		cipher.xor_bytes(mut (*dst)[..x.block_size], src[..x.block_size], iv)
-		x.b.encrypt(mut (*dst)[..x.block_size], mut (*dst)[..x.block_size])
+		cipher.xor_bytes(mut dst[..x.block_size], src[..x.block_size], iv)
+		x.b.encrypt(mut dst[..x.block_size], mut dst[..x.block_size])
 
 		// Move to the next block with this block as the next iv.
-		iv = (*dst)[..x.block_size]
+		iv = dst[..x.block_size]
 		if x.block_size >= src.len {
 			src = []
 		} else {
 			src = src[x.block_size..]
 		}
-		(*dst) = (*dst)[x.block_size..]
+		dst = dst[x.block_size..]
 	}
 
 	// Save the iv for the next crypt_blocks call.

vlib/crypto/aes/aes_test.v

@@ -21,7 +21,8 @@ fn test_crypto_aes() {
 		panic('ciphertext is not a multiple of the block size')
 	}
 	mode := aes.new_cbc(block, iv)
-	mode.encrypt_blocks(mut ciphertext, ciphertext)
+	cipher_clone := ciphertext.clone()
+	mode.encrypt_blocks(mut ciphertext, cipher_clone)
 
 	assert ciphertext.hex() == 'c210459b514668ddc44674885e4979215265a6c44431a248421254ef357a8c2a308a8bddf5623af9df91737562041cf1'
 }

vlib/v/gen/fn.v

@@ -624,11 +624,16 @@ fn (mut g Gen) ref_or_deref_arg(arg ast.CallArg, expected_type table.Type) {
 	} else if arg_is_ptr && !expr_is_ptr {
 		if arg.is_mut {
 			if exp_sym.kind == .array {
+				if arg.expr is ast.Ident && (arg.expr as ast.Ident).kind == .variable {
+					g.write('&/*arr*/')
+					g.expr(arg.expr)
+				} else {
 					// Special case for mutable arrays. We can't `&` function
 					// results,	have to use `(array[]){ expr }[0]` hack.
 					g.write('&/*111*/(array[]){')
 					g.expr(arg.expr)
 					g.write('}[0]')
+				}
 				return
 			}
 		}